Squashed 'third_party/abseil/' content from commit ddf8e52a2
Change-Id: I330cdc687395c6605ad027b855e313ff4a2059e9
git-subtree-dir: third_party/abseil
git-subtree-split: ddf8e52a2918dd0ccec75d3e2426125fa3926724
diff --git a/absl/strings/internal/char_map.h b/absl/strings/internal/char_map.h
new file mode 100644
index 0000000..b9108b8
--- /dev/null
+++ b/absl/strings/internal/char_map.h
@@ -0,0 +1,154 @@
+// Copyright 2017 The Abseil Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+// Character Map Class
+//
+// A fast, bit-vector map for 8-bit unsigned characters.
+// This class is useful for non-character purposes as well.
+
+#ifndef ABSL_STRINGS_INTERNAL_CHAR_MAP_H_
+#define ABSL_STRINGS_INTERNAL_CHAR_MAP_H_
+
+#include <cstddef>
+#include <cstdint>
+#include <cstring>
+
+#include "absl/base/macros.h"
+#include "absl/base/port.h"
+
+namespace absl {
+namespace strings_internal {
+
+class Charmap {
+ public:
+ constexpr Charmap() : m_() {}
+
+ // Initializes with a given char*. Note that NUL is not treated as
+ // a terminator, but rather a char to be flicked.
+ Charmap(const char* str, int len) : m_() {
+ while (len--) SetChar(*str++);
+ }
+
+ // Initializes with a given char*. NUL is treated as a terminator
+ // and will not be in the charmap.
+ explicit Charmap(const char* str) : m_() {
+ while (*str) SetChar(*str++);
+ }
+
+ constexpr bool contains(unsigned char c) const {
+ return (m_[c / 64] >> (c % 64)) & 0x1;
+ }
+
+ // Returns true if and only if a character exists in both maps.
+ bool IntersectsWith(const Charmap& c) const {
+ for (size_t i = 0; i < ABSL_ARRAYSIZE(m_); ++i) {
+ if ((m_[i] & c.m_[i]) != 0) return true;
+ }
+ return false;
+ }
+
+ bool IsZero() const {
+ for (uint64_t c : m_) {
+ if (c != 0) return false;
+ }
+ return true;
+ }
+
+ // Containing only a single specified char.
+ static constexpr Charmap Char(char x) {
+ return Charmap(CharMaskForWord(x, 0), CharMaskForWord(x, 1),
+ CharMaskForWord(x, 2), CharMaskForWord(x, 3));
+ }
+
+ // Containing all the chars in the C-std::string 's'.
+ // Note that this is expensively recursive because of the C++11 constexpr
+ // formulation. Use only in constexpr initializers.
+ static constexpr Charmap FromString(const char* s) {
+ return *s == 0 ? Charmap() : (Char(*s) | FromString(s + 1));
+ }
+
+ // Containing all the chars in the closed interval [lo,hi].
+ static constexpr Charmap Range(char lo, char hi) {
+ return Charmap(RangeForWord(lo, hi, 0), RangeForWord(lo, hi, 1),
+ RangeForWord(lo, hi, 2), RangeForWord(lo, hi, 3));
+ }
+
+ friend constexpr Charmap operator&(const Charmap& a, const Charmap& b) {
+ return Charmap(a.m_[0] & b.m_[0], a.m_[1] & b.m_[1], a.m_[2] & b.m_[2],
+ a.m_[3] & b.m_[3]);
+ }
+
+ friend constexpr Charmap operator|(const Charmap& a, const Charmap& b) {
+ return Charmap(a.m_[0] | b.m_[0], a.m_[1] | b.m_[1], a.m_[2] | b.m_[2],
+ a.m_[3] | b.m_[3]);
+ }
+
+ friend constexpr Charmap operator~(const Charmap& a) {
+ return Charmap(~a.m_[0], ~a.m_[1], ~a.m_[2], ~a.m_[3]);
+ }
+
+ private:
+ constexpr Charmap(uint64_t b0, uint64_t b1, uint64_t b2, uint64_t b3)
+ : m_{b0, b1, b2, b3} {}
+
+ static constexpr uint64_t RangeForWord(unsigned char lo, unsigned char hi,
+ uint64_t word) {
+ return OpenRangeFromZeroForWord(hi + 1, word) &
+ ~OpenRangeFromZeroForWord(lo, word);
+ }
+
+ // All the chars in the specified word of the range [0, upper).
+ static constexpr uint64_t OpenRangeFromZeroForWord(uint64_t upper,
+ uint64_t word) {
+ return (upper <= 64 * word)
+ ? 0
+ : (upper >= 64 * (word + 1))
+ ? ~static_cast<uint64_t>(0)
+ : (~static_cast<uint64_t>(0) >> (64 - upper % 64));
+ }
+
+ static constexpr uint64_t CharMaskForWord(unsigned char x, uint64_t word) {
+ return (x / 64 == word) ? (static_cast<uint64_t>(1) << (x % 64)) : 0;
+ }
+
+ private:
+ void SetChar(unsigned char c) {
+ m_[c / 64] |= static_cast<uint64_t>(1) << (c % 64);
+ }
+
+ uint64_t m_[4];
+};
+
+// Mirror the char-classifying predicates in <cctype>
+constexpr Charmap UpperCharmap() { return Charmap::Range('A', 'Z'); }
+constexpr Charmap LowerCharmap() { return Charmap::Range('a', 'z'); }
+constexpr Charmap DigitCharmap() { return Charmap::Range('0', '9'); }
+constexpr Charmap AlphaCharmap() { return LowerCharmap() | UpperCharmap(); }
+constexpr Charmap AlnumCharmap() { return DigitCharmap() | AlphaCharmap(); }
+constexpr Charmap XDigitCharmap() {
+ return DigitCharmap() | Charmap::Range('A', 'F') | Charmap::Range('a', 'f');
+}
+constexpr Charmap PrintCharmap() { return Charmap::Range(0x20, 0x7e); }
+constexpr Charmap SpaceCharmap() { return Charmap::FromString("\t\n\v\f\r "); }
+constexpr Charmap CntrlCharmap() {
+ return Charmap::Range(0, 0x7f) & ~PrintCharmap();
+}
+constexpr Charmap BlankCharmap() { return Charmap::FromString("\t "); }
+constexpr Charmap GraphCharmap() { return PrintCharmap() & ~SpaceCharmap(); }
+constexpr Charmap PunctCharmap() { return GraphCharmap() & ~AlnumCharmap(); }
+
+} // namespace strings_internal
+} // namespace absl
+
+#endif // ABSL_STRINGS_INTERNAL_CHAR_MAP_H_
diff --git a/absl/strings/internal/char_map_benchmark.cc b/absl/strings/internal/char_map_benchmark.cc
new file mode 100644
index 0000000..5cef967
--- /dev/null
+++ b/absl/strings/internal/char_map_benchmark.cc
@@ -0,0 +1,61 @@
+// Copyright 2017 The Abseil Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include "absl/strings/internal/char_map.h"
+
+#include <cstdint>
+
+#include "benchmark/benchmark.h"
+
+namespace {
+
+absl::strings_internal::Charmap MakeBenchmarkMap() {
+ absl::strings_internal::Charmap m;
+ uint32_t x[] = {0x0, 0x1, 0x2, 0x3, 0xf, 0xe, 0xd, 0xc};
+ for (uint32_t& t : x) t *= static_cast<uint32_t>(0x11111111UL);
+ for (uint32_t i = 0; i < 256; ++i) {
+ if ((x[i / 32] >> (i % 32)) & 1)
+ m = m | absl::strings_internal::Charmap::Char(i);
+ }
+ return m;
+}
+
+// Micro-benchmark for Charmap::contains.
+void BM_Contains(benchmark::State& state) {
+ // Loop-body replicated 10 times to increase time per iteration.
+ // Argument continuously changed to avoid generating common subexpressions.
+ const absl::strings_internal::Charmap benchmark_map = MakeBenchmarkMap();
+ unsigned char c = 0;
+ int ops = 0;
+ for (auto _ : state) {
+ ops += benchmark_map.contains(c++);
+ ops += benchmark_map.contains(c++);
+ ops += benchmark_map.contains(c++);
+ ops += benchmark_map.contains(c++);
+ ops += benchmark_map.contains(c++);
+ ops += benchmark_map.contains(c++);
+ ops += benchmark_map.contains(c++);
+ ops += benchmark_map.contains(c++);
+ ops += benchmark_map.contains(c++);
+ ops += benchmark_map.contains(c++);
+ }
+ benchmark::DoNotOptimize(ops);
+}
+BENCHMARK(BM_Contains);
+
+// We don't bother benchmarking Charmap::IsZero or Charmap::IntersectsWith;
+// their running time is data-dependent and it is not worth characterizing
+// "typical" data.
+
+} // namespace
diff --git a/absl/strings/internal/char_map_test.cc b/absl/strings/internal/char_map_test.cc
new file mode 100644
index 0000000..d330624
--- /dev/null
+++ b/absl/strings/internal/char_map_test.cc
@@ -0,0 +1,172 @@
+// Copyright 2017 The Abseil Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include "absl/strings/internal/char_map.h"
+
+#include <cctype>
+#include <string>
+#include <vector>
+
+#include "gmock/gmock.h"
+#include "gtest/gtest.h"
+
+namespace {
+
+constexpr absl::strings_internal::Charmap everything_map =
+ ~absl::strings_internal::Charmap();
+constexpr absl::strings_internal::Charmap nothing_map{};
+
+TEST(Charmap, AllTests) {
+ const absl::strings_internal::Charmap also_nothing_map("", 0);
+ ASSERT_TRUE(everything_map.contains('\0'));
+ ASSERT_TRUE(!nothing_map.contains('\0'));
+ ASSERT_TRUE(!also_nothing_map.contains('\0'));
+ for (unsigned char ch = 1; ch != 0; ++ch) {
+ ASSERT_TRUE(everything_map.contains(ch));
+ ASSERT_TRUE(!nothing_map.contains(ch));
+ ASSERT_TRUE(!also_nothing_map.contains(ch));
+ }
+
+ const absl::strings_internal::Charmap symbols("&@#@^!@?", 5);
+ ASSERT_TRUE(symbols.contains('&'));
+ ASSERT_TRUE(symbols.contains('@'));
+ ASSERT_TRUE(symbols.contains('#'));
+ ASSERT_TRUE(symbols.contains('^'));
+ ASSERT_TRUE(!symbols.contains('!'));
+ ASSERT_TRUE(!symbols.contains('?'));
+ int cnt = 0;
+ for (unsigned char ch = 1; ch != 0; ++ch)
+ cnt += symbols.contains(ch);
+ ASSERT_EQ(cnt, 4);
+
+ const absl::strings_internal::Charmap lets("^abcde", 3);
+ const absl::strings_internal::Charmap lets2("fghij\0klmnop", 10);
+ const absl::strings_internal::Charmap lets3("fghij\0klmnop");
+ ASSERT_TRUE(lets2.contains('k'));
+ ASSERT_TRUE(!lets3.contains('k'));
+
+ ASSERT_TRUE(symbols.IntersectsWith(lets));
+ ASSERT_TRUE(!lets2.IntersectsWith(lets));
+ ASSERT_TRUE(lets.IntersectsWith(symbols));
+ ASSERT_TRUE(!lets.IntersectsWith(lets2));
+
+ ASSERT_TRUE(nothing_map.IsZero());
+ ASSERT_TRUE(!lets.IsZero());
+}
+
+namespace {
+std::string Members(const absl::strings_internal::Charmap& m) {
+ std::string r;
+ for (size_t i = 0; i < 256; ++i)
+ if (m.contains(i)) r.push_back(i);
+ return r;
+}
+
+std::string ClosedRangeString(unsigned char lo, unsigned char hi) {
+ // Don't depend on lo<hi. Just increment until lo==hi.
+ std::string s;
+ while (true) {
+ s.push_back(lo);
+ if (lo == hi) break;
+ ++lo;
+ }
+ return s;
+}
+
+} // namespace
+
+TEST(Charmap, Constexpr) {
+ constexpr absl::strings_internal::Charmap kEmpty = nothing_map;
+ EXPECT_THAT(Members(kEmpty), "");
+ constexpr absl::strings_internal::Charmap kA =
+ absl::strings_internal::Charmap::Char('A');
+ EXPECT_THAT(Members(kA), "A");
+ constexpr absl::strings_internal::Charmap kAZ =
+ absl::strings_internal::Charmap::Range('A', 'Z');
+ EXPECT_THAT(Members(kAZ), "ABCDEFGHIJKLMNOPQRSTUVWXYZ");
+ constexpr absl::strings_internal::Charmap kIdentifier =
+ absl::strings_internal::Charmap::Range('0', '9') |
+ absl::strings_internal::Charmap::Range('A', 'Z') |
+ absl::strings_internal::Charmap::Range('a', 'z') |
+ absl::strings_internal::Charmap::Char('_');
+ EXPECT_THAT(Members(kIdentifier),
+ "0123456789"
+ "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
+ "_"
+ "abcdefghijklmnopqrstuvwxyz");
+ constexpr absl::strings_internal::Charmap kAll = everything_map;
+ for (size_t i = 0; i < 256; ++i) {
+ EXPECT_TRUE(kAll.contains(i)) << i;
+ }
+ constexpr absl::strings_internal::Charmap kHello =
+ absl::strings_internal::Charmap::FromString("Hello, world!");
+ EXPECT_THAT(Members(kHello), " !,Hdelorw");
+
+ // test negation and intersection
+ constexpr absl::strings_internal::Charmap kABC =
+ absl::strings_internal::Charmap::Range('A', 'Z') &
+ ~absl::strings_internal::Charmap::Range('D', 'Z');
+ EXPECT_THAT(Members(kABC), "ABC");
+}
+
+TEST(Charmap, Range) {
+ // Exhaustive testing takes too long, so test some of the boundaries that
+ // are perhaps going to cause trouble.
+ std::vector<size_t> poi = {0, 1, 2, 3, 4, 7, 8, 9, 15,
+ 16, 17, 30, 31, 32, 33, 63, 64, 65,
+ 127, 128, 129, 223, 224, 225, 254, 255};
+ for (auto lo = poi.begin(); lo != poi.end(); ++lo) {
+ SCOPED_TRACE(*lo);
+ for (auto hi = lo; hi != poi.end(); ++hi) {
+ SCOPED_TRACE(*hi);
+ EXPECT_THAT(Members(absl::strings_internal::Charmap::Range(*lo, *hi)),
+ ClosedRangeString(*lo, *hi));
+ }
+ }
+}
+
+bool AsBool(int x) { return static_cast<bool>(x); }
+
+TEST(CharmapCtype, Match) {
+ for (int c = 0; c < 256; ++c) {
+ SCOPED_TRACE(c);
+ SCOPED_TRACE(static_cast<char>(c));
+ EXPECT_EQ(AsBool(std::isupper(c)),
+ absl::strings_internal::UpperCharmap().contains(c));
+ EXPECT_EQ(AsBool(std::islower(c)),
+ absl::strings_internal::LowerCharmap().contains(c));
+ EXPECT_EQ(AsBool(std::isdigit(c)),
+ absl::strings_internal::DigitCharmap().contains(c));
+ EXPECT_EQ(AsBool(std::isalpha(c)),
+ absl::strings_internal::AlphaCharmap().contains(c));
+ EXPECT_EQ(AsBool(std::isalnum(c)),
+ absl::strings_internal::AlnumCharmap().contains(c));
+ EXPECT_EQ(AsBool(std::isxdigit(c)),
+ absl::strings_internal::XDigitCharmap().contains(c));
+ EXPECT_EQ(AsBool(std::isprint(c)),
+ absl::strings_internal::PrintCharmap().contains(c));
+ EXPECT_EQ(AsBool(std::isspace(c)),
+ absl::strings_internal::SpaceCharmap().contains(c));
+ EXPECT_EQ(AsBool(std::iscntrl(c)),
+ absl::strings_internal::CntrlCharmap().contains(c));
+ EXPECT_EQ(AsBool(std::isblank(c)),
+ absl::strings_internal::BlankCharmap().contains(c));
+ EXPECT_EQ(AsBool(std::isgraph(c)),
+ absl::strings_internal::GraphCharmap().contains(c));
+ EXPECT_EQ(AsBool(std::ispunct(c)),
+ absl::strings_internal::PunctCharmap().contains(c));
+ }
+}
+
+} // namespace
diff --git a/absl/strings/internal/charconv_bigint.cc b/absl/strings/internal/charconv_bigint.cc
new file mode 100644
index 0000000..95d471d
--- /dev/null
+++ b/absl/strings/internal/charconv_bigint.cc
@@ -0,0 +1,357 @@
+// Copyright 2018 The Abseil Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include "absl/strings/internal/charconv_bigint.h"
+
+#include <algorithm>
+#include <cassert>
+#include <string>
+
+namespace absl {
+namespace strings_internal {
+
+namespace {
+
+// Table containing some large powers of 5, for fast computation.
+
+// Constant step size for entries in the kLargePowersOfFive table. Each entry
+// is larger than the previous entry by a factor of 5**kLargePowerOfFiveStep
+// (or 5**27).
+//
+// In other words, the Nth entry in the table is 5**(27*N).
+//
+// 5**27 is the largest power of 5 that fits in 64 bits.
+constexpr int kLargePowerOfFiveStep = 27;
+
+// The largest legal index into the kLargePowersOfFive table.
+//
+// In other words, the largest precomputed power of 5 is 5**(27*20).
+constexpr int kLargestPowerOfFiveIndex = 20;
+
+// Table of powers of (5**27), up to (5**27)**20 == 5**540.
+//
+// Used to generate large powers of 5 while limiting the number of repeated
+// multiplications required.
+//
+// clang-format off
+const uint32_t kLargePowersOfFive[] = {
+// 5**27 (i=1), start=0, end=2
+ 0xfa10079dU, 0x6765c793U,
+// 5**54 (i=2), start=2, end=6
+ 0x97d9f649U, 0x6664242dU, 0x29939b14U, 0x29c30f10U,
+// 5**81 (i=3), start=6, end=12
+ 0xc4f809c5U, 0x7bf3f22aU, 0x67bdae34U, 0xad340517U, 0x369d1b5fU, 0x10de1593U,
+// 5**108 (i=4), start=12, end=20
+ 0x92b260d1U, 0x9efff7c7U, 0x81de0ec6U, 0xaeba5d56U, 0x410664a4U, 0x4f40737aU,
+ 0x20d3846fU, 0x06d00f73U,
+// 5**135 (i=5), start=20, end=30
+ 0xff1b172dU, 0x13a1d71cU, 0xefa07617U, 0x7f682d3dU, 0xff8c90c0U, 0x3f0131e7U,
+ 0x3fdcb9feU, 0x917b0177U, 0x16c407a7U, 0x02c06b9dU,
+// 5**162 (i=6), start=30, end=42
+ 0x960f7199U, 0x056667ecU, 0xe07aefd8U, 0x80f2b9ccU, 0x8273f5e3U, 0xeb9a214aU,
+ 0x40b38005U, 0x0e477ad4U, 0x277d08e6U, 0xfa28b11eU, 0xd3f7d784U, 0x011c835bU,
+// 5**189 (i=7), start=42, end=56
+ 0xf723d9d5U, 0x3282d3f3U, 0xe00857d1U, 0x69659d25U, 0x2cf117cfU, 0x24da6d07U,
+ 0x954d1417U, 0x3e5d8cedU, 0x7a8bb766U, 0xfd785ae6U, 0x645436d2U, 0x40c78b34U,
+ 0x94151217U, 0x0072e9f7U,
+// 5**216 (i=8), start=56, end=72
+ 0x2b416aa1U, 0x7893c5a7U, 0xe37dc6d4U, 0x2bad2beaU, 0xf0fc846cU, 0x7575ae4bU,
+ 0x62587b14U, 0x83b67a34U, 0x02110cdbU, 0xf7992f55U, 0x00deb022U, 0xa4a23becU,
+ 0x8af5c5cdU, 0xb85b654fU, 0x818df38bU, 0x002e69d2U,
+// 5**243 (i=9), start=72, end=90
+ 0x3518cbbdU, 0x20b0c15fU, 0x38756c2fU, 0xfb5dc3ddU, 0x22ad2d94U, 0xbf35a952U,
+ 0xa699192aU, 0x9a613326U, 0xad2a9cedU, 0xd7f48968U, 0xe87dfb54U, 0xc8f05db6U,
+ 0x5ef67531U, 0x31c1ab49U, 0xe202ac9fU, 0x9b2957b5U, 0xa143f6d3U, 0x0012bf07U,
+// 5**270 (i=10), start=90, end=110
+ 0x8b971de9U, 0x21aba2e1U, 0x63944362U, 0x57172336U, 0xd9544225U, 0xfb534166U,
+ 0x08c563eeU, 0x14640ee2U, 0x24e40d31U, 0x02b06537U, 0x03887f14U, 0x0285e533U,
+ 0xb744ef26U, 0x8be3a6c4U, 0x266979b4U, 0x6761ece2U, 0xd9cb39e4U, 0xe67de319U,
+ 0x0d39e796U, 0x00079250U,
+// 5**297 (i=11), start=110, end=132
+ 0x260eb6e5U, 0xf414a796U, 0xee1a7491U, 0xdb9368ebU, 0xf50c105bU, 0x59157750U,
+ 0x9ed2fb5cU, 0xf6e56d8bU, 0xeaee8d23U, 0x0f319f75U, 0x2aa134d6U, 0xac2908e9U,
+ 0xd4413298U, 0x02f02a55U, 0x989d5a7aU, 0x70dde184U, 0xba8040a7U, 0x03200981U,
+ 0xbe03b11cU, 0x3c1c2a18U, 0xd60427a1U, 0x00030ee0U,
+// 5**324 (i=12), start=132, end=156
+ 0xce566d71U, 0xf1c4aa25U, 0x4e93ca53U, 0xa72283d0U, 0x551a73eaU, 0x3d0538e2U,
+ 0x8da4303fU, 0x6a58de60U, 0x0e660221U, 0x49cf61a6U, 0x8d058fc1U, 0xb9d1a14cU,
+ 0x4bab157dU, 0xc85c6932U, 0x518c8b9eU, 0x9b92b8d0U, 0x0d8a0e21U, 0xbd855df9U,
+ 0xb3ea59a1U, 0x8da29289U, 0x4584d506U, 0x3752d80fU, 0xb72569c6U, 0x00013c33U,
+// 5**351 (i=13), start=156, end=182
+ 0x190f354dU, 0x83695cfeU, 0xe5a4d0c7U, 0xb60fb7e8U, 0xee5bbcc4U, 0xb922054cU,
+ 0xbb4f0d85U, 0x48394028U, 0x1d8957dbU, 0x0d7edb14U, 0x4ecc7587U, 0x505e9e02U,
+ 0x4c87f36bU, 0x99e66bd6U, 0x44b9ed35U, 0x753037d4U, 0xe5fe5f27U, 0x2742c203U,
+ 0x13b2ed2bU, 0xdc525d2cU, 0xe6fde59aU, 0x77ffb18fU, 0x13c5752cU, 0x08a84bccU,
+ 0x859a4940U, 0x00007fb6U,
+// 5**378 (i=14), start=182, end=210
+ 0x4f98cb39U, 0xa60edbbcU, 0x83b5872eU, 0xa501acffU, 0x9cc76f78U, 0xbadd4c73U,
+ 0x43e989faU, 0xca7acf80U, 0x2e0c824fU, 0xb19f4ffcU, 0x092fd81cU, 0xe4eb645bU,
+ 0xa1ff84c2U, 0x8a5a83baU, 0xa8a1fae9U, 0x1db43609U, 0xb0fed50bU, 0x0dd7d2bdU,
+ 0x7d7accd8U, 0x91fa640fU, 0x37dcc6c5U, 0x1c417fd5U, 0xe4d462adU, 0xe8a43399U,
+ 0x131bf9a5U, 0x8df54d29U, 0x36547dc1U, 0x00003395U,
+// 5**405 (i=15), start=210, end=240
+ 0x5bd330f5U, 0x77d21967U, 0x1ac481b7U, 0x6be2f7ceU, 0x7f4792a9U, 0xe84c2c52U,
+ 0x84592228U, 0x9dcaf829U, 0xdab44ce1U, 0x3d0c311bU, 0x532e297dU, 0x4704e8b4U,
+ 0x9cdc32beU, 0x41e64d9dU, 0x7717bea1U, 0xa824c00dU, 0x08f50b27U, 0x0f198d77U,
+ 0x49bbfdf0U, 0x025c6c69U, 0xd4e55cd3U, 0xf083602bU, 0xb9f0fecdU, 0xc0864aeaU,
+ 0x9cb98681U, 0xaaf620e9U, 0xacb6df30U, 0x4faafe66U, 0x8af13c3bU, 0x000014d5U,
+// 5**432 (i=16), start=240, end=272
+ 0x682bb941U, 0x89a9f297U, 0xcba75d7bU, 0x404217b1U, 0xb4e519e9U, 0xa1bc162bU,
+ 0xf7f5910aU, 0x98715af5U, 0x2ff53e57U, 0xe3ef118cU, 0x490c4543U, 0xbc9b1734U,
+ 0x2affbe4dU, 0x4cedcb4cU, 0xfb14e99eU, 0x35e34212U, 0xece39c24U, 0x07673ab3U,
+ 0xe73115ddU, 0xd15d38e7U, 0x093eed3bU, 0xf8e7eac5U, 0x78a8cc80U, 0x25227aacU,
+ 0x3f590551U, 0x413da1cbU, 0xdf643a55U, 0xab65ad44U, 0xd70b23d7U, 0xc672cd76U,
+ 0x3364ea62U, 0x0000086aU,
+// 5**459 (i=17), start=272, end=306
+ 0x22f163ddU, 0x23cf07acU, 0xbe2af6c2U, 0xf412f6f6U, 0xc3ff541eU, 0x6eeaf7deU,
+ 0xa47047e0U, 0x408cda92U, 0x0f0eeb08U, 0x56deba9dU, 0xcfc6b090U, 0x8bbbdf04U,
+ 0x3933cdb3U, 0x9e7bb67dU, 0x9f297035U, 0x38946244U, 0xee1d37bbU, 0xde898174U,
+ 0x63f3559dU, 0x705b72fbU, 0x138d27d9U, 0xf8603a78U, 0x735eec44U, 0xe30987d5U,
+ 0xc6d38070U, 0x9cfe548eU, 0x9ff01422U, 0x7c564aa8U, 0x91cc60baU, 0xcbc3565dU,
+ 0x7550a50bU, 0x6909aeadU, 0x13234c45U, 0x00000366U,
+// 5**486 (i=18), start=306, end=342
+ 0x17954989U, 0x3a7d7709U, 0x98042de5U, 0xa9011443U, 0x45e723c2U, 0x269ffd6fU,
+ 0x58852a46U, 0xaaa1042aU, 0x2eee8153U, 0xb2b6c39eU, 0xaf845b65U, 0xf6c365d7U,
+ 0xe4cffb2bU, 0xc840e90cU, 0xabea8abbU, 0x5c58f8d2U, 0x5c19fa3aU, 0x4670910aU,
+ 0x4449f21cU, 0xefa645b3U, 0xcc427decU, 0x083c3d73U, 0x467cb413U, 0x6fe10ae4U,
+ 0x3caffc72U, 0x9f8da55eU, 0x5e5c8ea7U, 0x490594bbU, 0xf0871b0bU, 0xdd89816cU,
+ 0x8e931df8U, 0xe85ce1c9U, 0xcca090a5U, 0x575fa16bU, 0x6b9f106cU, 0x0000015fU,
+// 5**513 (i=19), start=342, end=380
+ 0xee20d805U, 0x57bc3c07U, 0xcdea624eU, 0xd3f0f52dU, 0x9924b4f4U, 0xcf968640U,
+ 0x61d41962U, 0xe87fb464U, 0xeaaf51c7U, 0x564c8b60U, 0xccda4028U, 0x529428bbU,
+ 0x313a1fa8U, 0x96bd0f94U, 0x7a82ebaaU, 0xad99e7e9U, 0xf2668cd4U, 0xbe33a45eU,
+ 0xfd0db669U, 0x87ee369fU, 0xd3ec20edU, 0x9c4d7db7U, 0xdedcf0d8U, 0x7cd2ca64U,
+ 0xe25a6577U, 0x61003fd4U, 0xe56f54ccU, 0x10b7c748U, 0x40526e5eU, 0x7300ae87U,
+ 0x5c439261U, 0x2c0ff469U, 0xbf723f12U, 0xb2379b61U, 0xbf59b4f5U, 0xc91b1c3fU,
+ 0xf0046d27U, 0x0000008dU,
+// 5**540 (i=20), start=380, end=420
+ 0x525c9e11U, 0xf4e0eb41U, 0xebb2895dU, 0x5da512f9U, 0x7d9b29d4U, 0x452f4edcU,
+ 0x0b90bc37U, 0x341777cbU, 0x63d269afU, 0x1da77929U, 0x0a5c1826U, 0x77991898U,
+ 0x5aeddf86U, 0xf853a877U, 0x538c31ccU, 0xe84896daU, 0xb7a0010bU, 0x17ef4de5U,
+ 0xa52a2adeU, 0x029fd81cU, 0x987ce701U, 0x27fefd77U, 0xdb46c66fU, 0x5d301900U,
+ 0x496998c0U, 0xbb6598b9U, 0x5eebb607U, 0xe547354aU, 0xdf4a2f7eU, 0xf06c4955U,
+ 0x96242ffaU, 0x1775fb27U, 0xbecc58ceU, 0xebf2a53bU, 0x3eaad82aU, 0xf41137baU,
+ 0x573e6fbaU, 0xfb4866b8U, 0x54002148U, 0x00000039U,
+};
+// clang-format on
+
+// Returns a pointer to the big integer data for (5**27)**i. i must be
+// between 1 and 20, inclusive.
+const uint32_t* LargePowerOfFiveData(int i) {
+ return kLargePowersOfFive + i * (i - 1);
+}
+
+// Returns the size of the big integer data for (5**27)**i, in words. i must be
+// between 1 and 20, inclusive.
+int LargePowerOfFiveSize(int i) { return 2 * i; }
+} // namespace
+
+const uint32_t kFiveToNth[14] = {
+ 1, 5, 25, 125, 625, 3125, 15625,
+ 78125, 390625, 1953125, 9765625, 48828125, 244140625, 1220703125,
+};
+
+const uint32_t kTenToNth[10] = {
+ 1, 10, 100, 1000, 10000, 100000, 1000000, 10000000, 100000000, 1000000000,
+};
+
+template <int max_words>
+int BigUnsigned<max_words>::ReadFloatMantissa(const ParsedFloat& fp,
+ int significant_digits) {
+ SetToZero();
+ assert(fp.type == FloatType::kNumber);
+
+ if (fp.subrange_begin == nullptr) {
+ // We already exactly parsed the mantissa, so no more work is necessary.
+ words_[0] = fp.mantissa & 0xffffffffu;
+ words_[1] = fp.mantissa >> 32;
+ if (words_[1]) {
+ size_ = 2;
+ } else if (words_[0]) {
+ size_ = 1;
+ }
+ return fp.exponent;
+ }
+ int exponent_adjust =
+ ReadDigits(fp.subrange_begin, fp.subrange_end, significant_digits);
+ return fp.literal_exponent + exponent_adjust;
+}
+
+template <int max_words>
+int BigUnsigned<max_words>::ReadDigits(const char* begin, const char* end,
+ int significant_digits) {
+ assert(significant_digits <= Digits10() + 1);
+ SetToZero();
+
+ bool after_decimal_point = false;
+ // Discard any leading zeroes before the decimal point
+ while (begin < end && *begin == '0') {
+ ++begin;
+ }
+ int dropped_digits = 0;
+ // Discard any trailing zeroes. These may or may not be after the decimal
+ // point.
+ while (begin < end && *std::prev(end) == '0') {
+ --end;
+ ++dropped_digits;
+ }
+ if (begin < end && *std::prev(end) == '.') {
+ // If the std::string ends in '.', either before or after dropping zeroes, then
+ // drop the decimal point and look for more digits to drop.
+ dropped_digits = 0;
+ --end;
+ while (begin < end && *std::prev(end) == '0') {
+ --end;
+ ++dropped_digits;
+ }
+ } else if (dropped_digits) {
+ // We dropped digits, and aren't sure if they're before or after the decimal
+ // point. Figure that out now.
+ const char* dp = std::find(begin, end, '.');
+ if (dp != end) {
+ // The dropped trailing digits were after the decimal point, so don't
+ // count them.
+ dropped_digits = 0;
+ }
+ }
+ // Any non-fraction digits we dropped need to be accounted for in our exponent
+ // adjustment.
+ int exponent_adjust = dropped_digits;
+
+ uint32_t queued = 0;
+ int digits_queued = 0;
+ for (; begin != end && significant_digits > 0; ++begin) {
+ if (*begin == '.') {
+ after_decimal_point = true;
+ continue;
+ }
+ if (after_decimal_point) {
+ // For each fractional digit we emit in our parsed integer, adjust our
+ // decimal exponent to compensate.
+ --exponent_adjust;
+ }
+ int digit = (*begin - '0');
+ --significant_digits;
+ if (significant_digits == 0 && std::next(begin) != end &&
+ (digit == 0 || digit == 5)) {
+ // If this is the very last significant digit, but insignificant digits
+ // remain, we know that the last of those remaining significant digits is
+ // nonzero. (If it wasn't, we would have stripped it before we got here.)
+ // So if this final digit is a 0 or 5, adjust it upward by 1.
+ //
+ // This adjustment is what allows incredibly large mantissas ending in
+ // 500000...000000000001 to correctly round up, rather than to nearest.
+ ++digit;
+ }
+ queued = 10 * queued + digit;
+ ++digits_queued;
+ if (digits_queued == kMaxSmallPowerOfTen) {
+ MultiplyBy(kTenToNth[kMaxSmallPowerOfTen]);
+ AddWithCarry(0, queued);
+ queued = digits_queued = 0;
+ }
+ }
+ // Encode any remaining digits.
+ if (digits_queued) {
+ MultiplyBy(kTenToNth[digits_queued]);
+ AddWithCarry(0, queued);
+ }
+
+ // If any insignificant digits remain, we will drop them. But if we have not
+ // yet read the decimal point, then we have to adjust the exponent to account
+ // for the dropped digits.
+ if (begin < end && !after_decimal_point) {
+ // This call to std::find will result in a pointer either to the decimal
+ // point, or to the end of our buffer if there was none.
+ //
+ // Either way, [begin, decimal_point) will contain the set of dropped digits
+ // that require an exponent adjustment.
+ const char* decimal_point = std::find(begin, end, '.');
+ exponent_adjust += (decimal_point - begin);
+ }
+ return exponent_adjust;
+}
+
+template <int max_words>
+/* static */ BigUnsigned<max_words> BigUnsigned<max_words>::FiveToTheNth(
+ int n) {
+ BigUnsigned answer(1u);
+
+ // Seed from the table of large powers, if possible.
+ bool first_pass = true;
+ while (n >= kLargePowerOfFiveStep) {
+ int big_power =
+ std::min(n / kLargePowerOfFiveStep, kLargestPowerOfFiveIndex);
+ if (first_pass) {
+ // just copy, rather than multiplying by 1
+ std::copy(
+ LargePowerOfFiveData(big_power),
+ LargePowerOfFiveData(big_power) + LargePowerOfFiveSize(big_power),
+ answer.words_);
+ answer.size_ = LargePowerOfFiveSize(big_power);
+ first_pass = false;
+ } else {
+ answer.MultiplyBy(LargePowerOfFiveSize(big_power),
+ LargePowerOfFiveData(big_power));
+ }
+ n -= kLargePowerOfFiveStep * big_power;
+ }
+ answer.MultiplyByFiveToTheNth(n);
+ return answer;
+}
+
+template <int max_words>
+void BigUnsigned<max_words>::MultiplyStep(int original_size,
+ const uint32_t* other_words,
+ int other_size, int step) {
+ int this_i = std::min(original_size - 1, step);
+ int other_i = step - this_i;
+
+ uint64_t this_word = 0;
+ uint64_t carry = 0;
+ for (; this_i >= 0 && other_i < other_size; --this_i, ++other_i) {
+ uint64_t product = words_[this_i];
+ product *= other_words[other_i];
+ this_word += product;
+ carry += (this_word >> 32);
+ this_word &= 0xffffffff;
+ }
+ AddWithCarry(step + 1, carry);
+ words_[step] = this_word & 0xffffffff;
+ if (this_word > 0 && size_ <= step) {
+ size_ = step + 1;
+ }
+}
+
+template <int max_words>
+std::string BigUnsigned<max_words>::ToString() const {
+ BigUnsigned<max_words> copy = *this;
+ std::string result;
+ // Build result in reverse order
+ while (copy.size() > 0) {
+ int next_digit = copy.DivMod<10>();
+ result.push_back('0' + next_digit);
+ }
+ if (result.empty()) {
+ result.push_back('0');
+ }
+ std::reverse(result.begin(), result.end());
+ return result;
+}
+
+template class BigUnsigned<4>;
+template class BigUnsigned<84>;
+
+} // namespace strings_internal
+} // namespace absl
diff --git a/absl/strings/internal/charconv_bigint.h b/absl/strings/internal/charconv_bigint.h
new file mode 100644
index 0000000..7da9a7e
--- /dev/null
+++ b/absl/strings/internal/charconv_bigint.h
@@ -0,0 +1,419 @@
+// Copyright 2018 The Abseil Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef ABSL_STRINGS_INTERNAL_CHARCONV_BIGINT_H_
+#define ABSL_STRINGS_INTERNAL_CHARCONV_BIGINT_H_
+
+#include <algorithm>
+#include <cstdint>
+#include <iostream>
+#include <string>
+
+#include "absl/strings/ascii.h"
+#include "absl/strings/internal/charconv_parse.h"
+#include "absl/strings/string_view.h"
+
+namespace absl {
+namespace strings_internal {
+
+// The largest power that 5 that can be raised to, and still fit in a uint32_t.
+constexpr int kMaxSmallPowerOfFive = 13;
+// The largest power that 10 that can be raised to, and still fit in a uint32_t.
+constexpr int kMaxSmallPowerOfTen = 9;
+
+extern const uint32_t kFiveToNth[kMaxSmallPowerOfFive + 1];
+extern const uint32_t kTenToNth[kMaxSmallPowerOfTen + 1];
+
+// Large, fixed-width unsigned integer.
+//
+// Exact rounding for decimal-to-binary floating point conversion requires very
+// large integer math, but a design goal of absl::from_chars is to avoid
+// allocating memory. The integer precision needed for decimal-to-binary
+// conversions is large but bounded, so a huge fixed-width integer class
+// suffices.
+//
+// This is an intentionally limited big integer class. Only needed operations
+// are implemented. All storage lives in an array data member, and all
+// arithmetic is done in-place, to avoid requiring separate storage for operand
+// and result.
+//
+// This is an internal class. Some methods live in the .cc file, and are
+// instantiated only for the values of max_words we need.
+template <int max_words>
+class BigUnsigned {
+ public:
+ static_assert(max_words == 4 || max_words == 84,
+ "unsupported max_words value");
+
+ BigUnsigned() : size_(0), words_{} {}
+ explicit constexpr BigUnsigned(uint64_t v)
+ : size_((v >> 32) ? 2 : v ? 1 : 0),
+ words_{static_cast<uint32_t>(v & 0xffffffffu),
+ static_cast<uint32_t>(v >> 32)} {}
+
+ // Constructs a BigUnsigned from the given string_view containing a decimal
+ // value. If the input std::string is not a decimal integer, constructs a 0
+ // instead.
+ explicit BigUnsigned(absl::string_view sv) : size_(0), words_{} {
+ // Check for valid input, returning a 0 otherwise. This is reasonable
+ // behavior only because this constructor is for unit tests.
+ if (std::find_if_not(sv.begin(), sv.end(), ascii_isdigit) != sv.end() ||
+ sv.empty()) {
+ return;
+ }
+ int exponent_adjust =
+ ReadDigits(sv.data(), sv.data() + sv.size(), Digits10() + 1);
+ if (exponent_adjust > 0) {
+ MultiplyByTenToTheNth(exponent_adjust);
+ }
+ }
+
+ // Loads the mantissa value of a previously-parsed float.
+ //
+ // Returns the associated decimal exponent. The value of the parsed float is
+ // exactly *this * 10**exponent.
+ int ReadFloatMantissa(const ParsedFloat& fp, int significant_digits);
+
+ // Returns the number of decimal digits of precision this type provides. All
+ // numbers with this many decimal digits or fewer are representable by this
+ // type.
+ //
+ // Analagous to std::numeric_limits<BigUnsigned>::digits10.
+ static constexpr int Digits10() {
+ // 9975007/1035508 is very slightly less than log10(2**32).
+ return static_cast<uint64_t>(max_words) * 9975007 / 1035508;
+ }
+
+ // Shifts left by the given number of bits.
+ void ShiftLeft(int count) {
+ if (count > 0) {
+ const int word_shift = count / 32;
+ if (word_shift >= max_words) {
+ SetToZero();
+ return;
+ }
+ size_ = (std::min)(size_ + word_shift, max_words);
+ count %= 32;
+ if (count == 0) {
+ std::copy_backward(words_, words_ + size_ - word_shift, words_ + size_);
+ } else {
+ for (int i = (std::min)(size_, max_words - 1); i > word_shift; --i) {
+ words_[i] = (words_[i - word_shift] << count) |
+ (words_[i - word_shift - 1] >> (32 - count));
+ }
+ words_[word_shift] = words_[0] << count;
+ // Grow size_ if necessary.
+ if (size_ < max_words && words_[size_]) {
+ ++size_;
+ }
+ }
+ std::fill(words_, words_ + word_shift, 0u);
+ }
+ }
+
+
+ // Multiplies by v in-place.
+ void MultiplyBy(uint32_t v) {
+ if (size_ == 0 || v == 1) {
+ return;
+ }
+ if (v == 0) {
+ SetToZero();
+ return;
+ }
+ const uint64_t factor = v;
+ uint64_t window = 0;
+ for (int i = 0; i < size_; ++i) {
+ window += factor * words_[i];
+ words_[i] = window & 0xffffffff;
+ window >>= 32;
+ }
+ // If carry bits remain and there's space for them, grow size_.
+ if (window && size_ < max_words) {
+ words_[size_] = window & 0xffffffff;
+ ++size_;
+ }
+ }
+
+ void MultiplyBy(uint64_t v) {
+ uint32_t words[2];
+ words[0] = static_cast<uint32_t>(v);
+ words[1] = static_cast<uint32_t>(v >> 32);
+ if (words[1] == 0) {
+ MultiplyBy(words[0]);
+ } else {
+ MultiplyBy(2, words);
+ }
+ }
+
+ // Multiplies in place by 5 to the power of n. n must be non-negative.
+ void MultiplyByFiveToTheNth(int n) {
+ while (n >= kMaxSmallPowerOfFive) {
+ MultiplyBy(kFiveToNth[kMaxSmallPowerOfFive]);
+ n -= kMaxSmallPowerOfFive;
+ }
+ if (n > 0) {
+ MultiplyBy(kFiveToNth[n]);
+ }
+ }
+
+ // Multiplies in place by 10 to the power of n. n must be non-negative.
+ void MultiplyByTenToTheNth(int n) {
+ if (n > kMaxSmallPowerOfTen) {
+ // For large n, raise to a power of 5, then shift left by the same amount.
+ // (10**n == 5**n * 2**n.) This requires fewer multiplications overall.
+ MultiplyByFiveToTheNth(n);
+ ShiftLeft(n);
+ } else if (n > 0) {
+ // We can do this more quickly for very small N by using a single
+ // multiplication.
+ MultiplyBy(kTenToNth[n]);
+ }
+ }
+
+ // Returns the value of 5**n, for non-negative n. This implementation uses
+ // a lookup table, and is faster then seeding a BigUnsigned with 1 and calling
+ // MultiplyByFiveToTheNth().
+ static BigUnsigned FiveToTheNth(int n);
+
+ // Multiplies by another BigUnsigned, in-place.
+ template <int M>
+ void MultiplyBy(const BigUnsigned<M>& other) {
+ MultiplyBy(other.size(), other.words());
+ }
+
+ void SetToZero() {
+ std::fill(words_, words_ + size_, 0u);
+ size_ = 0;
+ }
+
+ // Returns the value of the nth word of this BigUnsigned. This is
+ // range-checked, and returns 0 on out-of-bounds accesses.
+ uint32_t GetWord(int index) const {
+ if (index < 0 || index >= size_) {
+ return 0;
+ }
+ return words_[index];
+ }
+
+ // Returns this integer as a decimal std::string. This is not used in the decimal-
+ // to-binary conversion; it is intended to aid in testing.
+ std::string ToString() const;
+
+ int size() const { return size_; }
+ const uint32_t* words() const { return words_; }
+
+ private:
+ // Reads the number between [begin, end), possibly containing a decimal point,
+ // into this BigUnsigned.
+ //
+ // Callers are required to ensure [begin, end) contains a valid number, with
+ // one or more decimal digits and at most one decimal point. This routine
+ // will behave unpredictably if these preconditions are not met.
+ //
+ // Only the first `significant_digits` digits are read. Digits beyond this
+ // limit are "sticky": If the final significant digit is 0 or 5, and if any
+ // dropped digit is nonzero, then that final significant digit is adjusted up
+ // to 1 or 6. This adjustment allows for precise rounding.
+ //
+ // Returns `exponent_adjustment`, a power-of-ten exponent adjustment to
+ // account for the decimal point and for dropped significant digits. After
+ // this function returns,
+ // actual_value_of_parsed_string ~= *this * 10**exponent_adjustment.
+ int ReadDigits(const char* begin, const char* end, int significant_digits);
+
+ // Performs a step of big integer multiplication. This computes the full
+ // (64-bit-wide) values that should be added at the given index (step), and
+ // adds to that location in-place.
+ //
+ // Because our math all occurs in place, we must multiply starting from the
+ // highest word working downward. (This is a bit more expensive due to the
+ // extra carries involved.)
+ //
+ // This must be called in steps, for each word to be calculated, starting from
+ // the high end and working down to 0. The first value of `step` should be
+ // `std::min(original_size + other.size_ - 2, max_words - 1)`.
+ // The reason for this expression is that multiplying the i'th word from one
+ // multiplicand and the j'th word of another multiplicand creates a
+ // two-word-wide value to be stored at the (i+j)'th element. The highest
+ // word indices we will access are `original_size - 1` from this object, and
+ // `other.size_ - 1` from our operand. Therefore,
+ // `original_size + other.size_ - 2` is the first step we should calculate,
+ // but limited on an upper bound by max_words.
+
+ // Working from high-to-low ensures that we do not overwrite the portions of
+ // the initial value of *this which are still needed for later steps.
+ //
+ // Once called with step == 0, *this contains the result of the
+ // multiplication.
+ //
+ // `original_size` is the size_ of *this before the first call to
+ // MultiplyStep(). `other_words` and `other_size` are the contents of our
+ // operand. `step` is the step to perform, as described above.
+ void MultiplyStep(int original_size, const uint32_t* other_words,
+ int other_size, int step);
+
+ void MultiplyBy(int other_size, const uint32_t* other_words) {
+ const int original_size = size_;
+ const int first_step =
+ (std::min)(original_size + other_size - 2, max_words - 1);
+ for (int step = first_step; step >= 0; --step) {
+ MultiplyStep(original_size, other_words, other_size, step);
+ }
+ }
+
+ // Adds a 32-bit value to the index'th word, with carry.
+ void AddWithCarry(int index, uint32_t value) {
+ if (value) {
+ while (index < max_words && value > 0) {
+ words_[index] += value;
+ // carry if we overflowed in this word:
+ if (value > words_[index]) {
+ value = 1;
+ ++index;
+ } else {
+ value = 0;
+ }
+ }
+ size_ = (std::min)(max_words, (std::max)(index + 1, size_));
+ }
+ }
+
+ void AddWithCarry(int index, uint64_t value) {
+ if (value && index < max_words) {
+ uint32_t high = value >> 32;
+ uint32_t low = value & 0xffffffff;
+ words_[index] += low;
+ if (words_[index] < low) {
+ ++high;
+ if (high == 0) {
+ // Carry from the low word caused our high word to overflow.
+ // Short circuit here to do the right thing.
+ AddWithCarry(index + 2, static_cast<uint32_t>(1));
+ return;
+ }
+ }
+ if (high > 0) {
+ AddWithCarry(index + 1, high);
+ } else {
+ // Normally 32-bit AddWithCarry() sets size_, but since we don't call
+ // it when `high` is 0, do it ourselves here.
+ size_ = (std::min)(max_words, (std::max)(index + 1, size_));
+ }
+ }
+ }
+
+ // Divide this in place by a constant divisor. Returns the remainder of the
+ // division.
+ template <uint32_t divisor>
+ uint32_t DivMod() {
+ uint64_t accumulator = 0;
+ for (int i = size_ - 1; i >= 0; --i) {
+ accumulator <<= 32;
+ accumulator += words_[i];
+ // accumulator / divisor will never overflow an int32_t in this loop
+ words_[i] = static_cast<uint32_t>(accumulator / divisor);
+ accumulator = accumulator % divisor;
+ }
+ while (size_ > 0 && words_[size_ - 1] == 0) {
+ --size_;
+ }
+ return static_cast<uint32_t>(accumulator);
+ }
+
+ // The number of elements in words_ that may carry significant values.
+ // All elements beyond this point are 0.
+ //
+ // When size_ is 0, this BigUnsigned stores the value 0.
+ // When size_ is nonzero, is *not* guaranteed that words_[size_ - 1] is
+ // nonzero. This can occur due to overflow truncation.
+ // In particular, x.size_ != y.size_ does *not* imply x != y.
+ int size_;
+ uint32_t words_[max_words];
+};
+
+// Compares two big integer instances.
+//
+// Returns -1 if lhs < rhs, 0 if lhs == rhs, and 1 if lhs > rhs.
+template <int N, int M>
+int Compare(const BigUnsigned<N>& lhs, const BigUnsigned<M>& rhs) {
+ int limit = (std::max)(lhs.size(), rhs.size());
+ for (int i = limit - 1; i >= 0; --i) {
+ const uint32_t lhs_word = lhs.GetWord(i);
+ const uint32_t rhs_word = rhs.GetWord(i);
+ if (lhs_word < rhs_word) {
+ return -1;
+ } else if (lhs_word > rhs_word) {
+ return 1;
+ }
+ }
+ return 0;
+}
+
+template <int N, int M>
+bool operator==(const BigUnsigned<N>& lhs, const BigUnsigned<M>& rhs) {
+ int limit = (std::max)(lhs.size(), rhs.size());
+ for (int i = 0; i < limit; ++i) {
+ if (lhs.GetWord(i) != rhs.GetWord(i)) {
+ return false;
+ }
+ }
+ return true;
+}
+
+template <int N, int M>
+bool operator!=(const BigUnsigned<N>& lhs, const BigUnsigned<M>& rhs) {
+ return !(lhs == rhs);
+}
+
+template <int N, int M>
+bool operator<(const BigUnsigned<N>& lhs, const BigUnsigned<M>& rhs) {
+ return Compare(lhs, rhs) == -1;
+}
+
+template <int N, int M>
+bool operator>(const BigUnsigned<N>& lhs, const BigUnsigned<M>& rhs) {
+ return rhs < lhs;
+}
+template <int N, int M>
+bool operator<=(const BigUnsigned<N>& lhs, const BigUnsigned<M>& rhs) {
+ return !(rhs < lhs);
+}
+template <int N, int M>
+bool operator>=(const BigUnsigned<N>& lhs, const BigUnsigned<M>& rhs) {
+ return !(lhs < rhs);
+}
+
+// Output operator for BigUnsigned, for testing purposes only.
+template <int N>
+std::ostream& operator<<(std::ostream& os, const BigUnsigned<N>& num) {
+ return os << num.ToString();
+}
+
+// Explicit instantiation declarations for the sizes of BigUnsigned that we
+// are using.
+//
+// For now, the choices of 4 and 84 are arbitrary; 4 is a small value that is
+// still bigger than an int128, and 84 is a large value we will want to use
+// in the from_chars implementation.
+//
+// Comments justifying the use of 84 belong in the from_chars implementation,
+// and will be added in a follow-up CL.
+extern template class BigUnsigned<4>;
+extern template class BigUnsigned<84>;
+
+} // namespace strings_internal
+} // namespace absl
+
+#endif // ABSL_STRINGS_INTERNAL_CHARCONV_BIGINT_H_
diff --git a/absl/strings/internal/charconv_bigint_test.cc b/absl/strings/internal/charconv_bigint_test.cc
new file mode 100644
index 0000000..745714a
--- /dev/null
+++ b/absl/strings/internal/charconv_bigint_test.cc
@@ -0,0 +1,203 @@
+// Copyright 2018 The Abseil Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include "absl/strings/internal/charconv_bigint.h"
+
+#include <string>
+
+#include "gtest/gtest.h"
+
+namespace absl {
+namespace strings_internal {
+
+TEST(BigUnsigned, ShiftLeft) {
+ {
+ // Check that 3 * 2**100 is calculated correctly
+ BigUnsigned<4> num(3u);
+ num.ShiftLeft(100);
+ EXPECT_EQ(num, BigUnsigned<4>("3802951800684688204490109616128"));
+ }
+ {
+ // Test that overflow is truncated properly.
+ // 15 is 4 bits long, and BigUnsigned<4> is a 128-bit bigint.
+ // Shifting left by 125 bits should truncate off the high bit, so that
+ // 15 << 125 == 7 << 125
+ // after truncation.
+ BigUnsigned<4> a(15u);
+ BigUnsigned<4> b(7u);
+ BigUnsigned<4> c(3u);
+ a.ShiftLeft(125);
+ b.ShiftLeft(125);
+ c.ShiftLeft(125);
+ EXPECT_EQ(a, b);
+ EXPECT_NE(a, c);
+ }
+ {
+ // Same test, larger bigint:
+ BigUnsigned<84> a(15u);
+ BigUnsigned<84> b(7u);
+ BigUnsigned<84> c(3u);
+ a.ShiftLeft(84 * 32 - 3);
+ b.ShiftLeft(84 * 32 - 3);
+ c.ShiftLeft(84 * 32 - 3);
+ EXPECT_EQ(a, b);
+ EXPECT_NE(a, c);
+ }
+ {
+ // Check that incrementally shifting has the same result as doing it all at
+ // once (attempting to capture corner cases.)
+ const std::string seed = "1234567890123456789012345678901234567890";
+ BigUnsigned<84> a(seed);
+ for (int i = 1; i <= 84 * 32; ++i) {
+ a.ShiftLeft(1);
+ BigUnsigned<84> b(seed);
+ b.ShiftLeft(i);
+ EXPECT_EQ(a, b);
+ }
+ // And we should have fully rotated all bits off by now:
+ EXPECT_EQ(a, BigUnsigned<84>(0u));
+ }
+}
+
+TEST(BigUnsigned, MultiplyByUint32) {
+ const BigUnsigned<84> factorial_100(
+ "933262154439441526816992388562667004907159682643816214685929638952175999"
+ "932299156089414639761565182862536979208272237582511852109168640000000000"
+ "00000000000000");
+ BigUnsigned<84> a(1u);
+ for (uint32_t i = 1; i <= 100; ++i) {
+ a.MultiplyBy(i);
+ }
+ EXPECT_EQ(a, BigUnsigned<84>(factorial_100));
+}
+
+TEST(BigUnsigned, MultiplyByBigUnsigned) {
+ {
+ // Put the terms of factorial_200 into two bigints, and multiply them
+ // together.
+ const BigUnsigned<84> factorial_200(
+ "7886578673647905035523632139321850622951359776871732632947425332443594"
+ "4996340334292030428401198462390417721213891963883025764279024263710506"
+ "1926624952829931113462857270763317237396988943922445621451664240254033"
+ "2918641312274282948532775242424075739032403212574055795686602260319041"
+ "7032406235170085879617892222278962370389737472000000000000000000000000"
+ "0000000000000000000000000");
+ BigUnsigned<84> evens(1u);
+ BigUnsigned<84> odds(1u);
+ for (uint32_t i = 1; i < 200; i += 2) {
+ odds.MultiplyBy(i);
+ evens.MultiplyBy(i + 1);
+ }
+ evens.MultiplyBy(odds);
+ EXPECT_EQ(evens, factorial_200);
+ }
+ {
+ // Multiply various powers of 10 together.
+ for (int a = 0 ; a < 700; a += 25) {
+ SCOPED_TRACE(a);
+ BigUnsigned<84> a_value("3" + std::string(a, '0'));
+ for (int b = 0; b < (700 - a); b += 25) {
+ SCOPED_TRACE(b);
+ BigUnsigned<84> b_value("2" + std::string(b, '0'));
+ BigUnsigned<84> expected_product("6" + std::string(a + b, '0'));
+ b_value.MultiplyBy(a_value);
+ EXPECT_EQ(b_value, expected_product);
+ }
+ }
+ }
+}
+
+TEST(BigUnsigned, MultiplyByOverflow) {
+ {
+ // Check that multiplcation overflow predictably truncates.
+
+ // A big int with all bits on.
+ BigUnsigned<4> all_bits_on("340282366920938463463374607431768211455");
+ // Modulo 2**128, this is equal to -1. Therefore the square of this,
+ // modulo 2**128, should be 1.
+ all_bits_on.MultiplyBy(all_bits_on);
+ EXPECT_EQ(all_bits_on, BigUnsigned<4>(1u));
+ }
+ {
+ // Try multiplying a large bigint by 2**50, and compare the result to
+ // shifting.
+ BigUnsigned<4> value_1("12345678901234567890123456789012345678");
+ BigUnsigned<4> value_2("12345678901234567890123456789012345678");
+ BigUnsigned<4> two_to_fiftieth(1u);
+ two_to_fiftieth.ShiftLeft(50);
+
+ value_1.ShiftLeft(50);
+ value_2.MultiplyBy(two_to_fiftieth);
+ EXPECT_EQ(value_1, value_2);
+ }
+}
+
+TEST(BigUnsigned, FiveToTheNth) {
+ {
+ // Sanity check that MultiplyByFiveToTheNth gives consistent answers, up to
+ // and including overflow.
+ for (int i = 0; i < 1160; ++i) {
+ SCOPED_TRACE(i);
+ BigUnsigned<84> value_1(123u);
+ BigUnsigned<84> value_2(123u);
+ value_1.MultiplyByFiveToTheNth(i);
+ for (int j = 0; j < i; j++) {
+ value_2.MultiplyBy(5u);
+ }
+ EXPECT_EQ(value_1, value_2);
+ }
+ }
+ {
+ // Check that the faster, table-lookup-based static method returns the same
+ // result that multiplying in-place would return, up to and including
+ // overflow.
+ for (int i = 0; i < 1160; ++i) {
+ SCOPED_TRACE(i);
+ BigUnsigned<84> value_1(1u);
+ value_1.MultiplyByFiveToTheNth(i);
+ BigUnsigned<84> value_2 = BigUnsigned<84>::FiveToTheNth(i);
+ EXPECT_EQ(value_1, value_2);
+ }
+ }
+}
+
+TEST(BigUnsigned, TenToTheNth) {
+ {
+ // Sanity check MultiplyByTenToTheNth.
+ for (int i = 0; i < 800; ++i) {
+ SCOPED_TRACE(i);
+ BigUnsigned<84> value_1(123u);
+ BigUnsigned<84> value_2(123u);
+ value_1.MultiplyByTenToTheNth(i);
+ for (int j = 0; j < i; j++) {
+ value_2.MultiplyBy(10u);
+ }
+ EXPECT_EQ(value_1, value_2);
+ }
+ }
+ {
+ // Alternate testing approach, taking advantage of the decimal parser.
+ for (int i = 0; i < 200; ++i) {
+ SCOPED_TRACE(i);
+ BigUnsigned<84> value_1(135u);
+ value_1.MultiplyByTenToTheNth(i);
+ BigUnsigned<84> value_2("135" + std::string(i, '0'));
+ EXPECT_EQ(value_1, value_2);
+ }
+ }
+}
+
+
+} // namespace strings_internal
+} // namespace absl
diff --git a/absl/strings/internal/charconv_parse.cc b/absl/strings/internal/charconv_parse.cc
new file mode 100644
index 0000000..f3c7232
--- /dev/null
+++ b/absl/strings/internal/charconv_parse.cc
@@ -0,0 +1,496 @@
+// Copyright 2018 The Abseil Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include "absl/strings/internal/charconv_parse.h"
+#include "absl/strings/charconv.h"
+
+#include <cassert>
+#include <cstdint>
+#include <limits>
+
+#include "absl/strings/internal/memutil.h"
+
+namespace absl {
+namespace {
+
+// ParseFloat<10> will read the first 19 significant digits of the mantissa.
+// This number was chosen for multiple reasons.
+//
+// (a) First, for whatever integer type we choose to represent the mantissa, we
+// want to choose the largest possible number of decimal digits for that integer
+// type. We are using uint64_t, which can express any 19-digit unsigned
+// integer.
+//
+// (b) Second, we need to parse enough digits that the binary value of any
+// mantissa we capture has more bits of resolution than the mantissa
+// representation in the target float. Our algorithm requires at least 3 bits
+// of headway, but 19 decimal digits give a little more than that.
+//
+// The following static assertions verify the above comments:
+constexpr int kDecimalMantissaDigitsMax = 19;
+
+static_assert(std::numeric_limits<uint64_t>::digits10 ==
+ kDecimalMantissaDigitsMax,
+ "(a) above");
+
+// IEEE doubles, which we assume in Abseil, have 53 binary bits of mantissa.
+static_assert(std::numeric_limits<double>::is_iec559, "IEEE double assumed");
+static_assert(std::numeric_limits<double>::radix == 2, "IEEE double fact");
+static_assert(std::numeric_limits<double>::digits == 53, "IEEE double fact");
+
+// The lowest valued 19-digit decimal mantissa we can read still contains
+// sufficient information to reconstruct a binary mantissa.
+static_assert(1000000000000000000u > (uint64_t(1) << (53 + 3)), "(b) above");
+
+// ParseFloat<16> will read the first 15 significant digits of the mantissa.
+//
+// Because a base-16-to-base-2 conversion can be done exactly, we do not need
+// to maximize the number of scanned hex digits to improve our conversion. What
+// is required is to scan two more bits than the mantissa can represent, so that
+// we always round correctly.
+//
+// (One extra bit does not suffice to perform correct rounding, since a number
+// exactly halfway between two representable floats has unique rounding rules,
+// so we need to differentiate between a "halfway between" number and a "closer
+// to the larger value" number.)
+constexpr int kHexadecimalMantissaDigitsMax = 15;
+
+// The minimum number of significant bits that will be read from
+// kHexadecimalMantissaDigitsMax hex digits. We must subtract by three, since
+// the most significant digit can be a "1", which only contributes a single
+// significant bit.
+constexpr int kGuaranteedHexadecimalMantissaBitPrecision =
+ 4 * kHexadecimalMantissaDigitsMax - 3;
+
+static_assert(kGuaranteedHexadecimalMantissaBitPrecision >
+ std::numeric_limits<double>::digits + 2,
+ "kHexadecimalMantissaDigitsMax too small");
+
+// We also impose a limit on the number of significant digits we will read from
+// an exponent, to avoid having to deal with integer overflow. We use 9 for
+// this purpose.
+//
+// If we read a 9 digit exponent, the end result of the conversion will
+// necessarily be infinity or zero, depending on the sign of the exponent.
+// Therefore we can just drop extra digits on the floor without any extra
+// logic.
+constexpr int kDecimalExponentDigitsMax = 9;
+static_assert(std::numeric_limits<int>::digits10 >= kDecimalExponentDigitsMax,
+ "int type too small");
+
+// To avoid incredibly large inputs causing integer overflow for our exponent,
+// we impose an arbitrary but very large limit on the number of significant
+// digits we will accept. The implementation refuses to match a string with
+// more consecutive significant mantissa digits than this.
+constexpr int kDecimalDigitLimit = 50000000;
+
+// Corresponding limit for hexadecimal digit inputs. This is one fourth the
+// amount of kDecimalDigitLimit, since each dropped hexadecimal digit requires
+// a binary exponent adjustment of 4.
+constexpr int kHexadecimalDigitLimit = kDecimalDigitLimit / 4;
+
+// The largest exponent we can read is 999999999 (per
+// kDecimalExponentDigitsMax), and the largest exponent adjustment we can get
+// from dropped mantissa digits is 2 * kDecimalDigitLimit, and the sum of these
+// comfortably fits in an integer.
+//
+// We count kDecimalDigitLimit twice because there are independent limits for
+// numbers before and after the decimal point. (In the case where there are no
+// significant digits before the decimal point, there are independent limits for
+// post-decimal-point leading zeroes and for significant digits.)
+static_assert(999999999 + 2 * kDecimalDigitLimit <
+ std::numeric_limits<int>::max(),
+ "int type too small");
+static_assert(999999999 + 2 * (4 * kHexadecimalDigitLimit) <
+ std::numeric_limits<int>::max(),
+ "int type too small");
+
+// Returns true if the provided bitfield allows parsing an exponent value
+// (e.g., "1.5e100").
+bool AllowExponent(chars_format flags) {
+ bool fixed = (flags & chars_format::fixed) == chars_format::fixed;
+ bool scientific =
+ (flags & chars_format::scientific) == chars_format::scientific;
+ return scientific || !fixed;
+}
+
+// Returns true if the provided bitfield requires an exponent value be present.
+bool RequireExponent(chars_format flags) {
+ bool fixed = (flags & chars_format::fixed) == chars_format::fixed;
+ bool scientific =
+ (flags & chars_format::scientific) == chars_format::scientific;
+ return scientific && !fixed;
+}
+
+const int8_t kAsciiToInt[256] = {
+ -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+ -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+ -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 0, 1, 2, 3, 4, 5, 6, 7, 8,
+ 9, -1, -1, -1, -1, -1, -1, -1, 10, 11, 12, 13, 14, 15, -1, -1, -1, -1, -1,
+ -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+ -1, -1, 10, 11, 12, 13, 14, 15, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+ -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+ -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+ -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+ -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+ -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+ -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+ -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+ -1, -1, -1, -1, -1, -1, -1, -1, -1};
+
+// Returns true if `ch` is a digit in the given base
+template <int base>
+bool IsDigit(char ch);
+
+// Converts a valid `ch` to its digit value in the given base.
+template <int base>
+unsigned ToDigit(char ch);
+
+// Returns true if `ch` is the exponent delimiter for the given base.
+template <int base>
+bool IsExponentCharacter(char ch);
+
+// Returns the maximum number of significant digits we will read for a float
+// in the given base.
+template <int base>
+constexpr int MantissaDigitsMax();
+
+// Returns the largest consecutive run of digits we will accept when parsing a
+// number in the given base.
+template <int base>
+constexpr int DigitLimit();
+
+// Returns the amount the exponent must be adjusted by for each dropped digit.
+// (For decimal this is 1, since the digits are in base 10 and the exponent base
+// is also 10, but for hexadecimal this is 4, since the digits are base 16 but
+// the exponent base is 2.)
+template <int base>
+constexpr int DigitMagnitude();
+
+template <>
+bool IsDigit<10>(char ch) {
+ return ch >= '0' && ch <= '9';
+}
+template <>
+bool IsDigit<16>(char ch) {
+ return kAsciiToInt[static_cast<unsigned char>(ch)] >= 0;
+}
+
+template <>
+unsigned ToDigit<10>(char ch) {
+ return ch - '0';
+}
+template <>
+unsigned ToDigit<16>(char ch) {
+ return kAsciiToInt[static_cast<unsigned char>(ch)];
+}
+
+template <>
+bool IsExponentCharacter<10>(char ch) {
+ return ch == 'e' || ch == 'E';
+}
+
+template <>
+bool IsExponentCharacter<16>(char ch) {
+ return ch == 'p' || ch == 'P';
+}
+
+template <>
+constexpr int MantissaDigitsMax<10>() {
+ return kDecimalMantissaDigitsMax;
+}
+template <>
+constexpr int MantissaDigitsMax<16>() {
+ return kHexadecimalMantissaDigitsMax;
+}
+
+template <>
+constexpr int DigitLimit<10>() {
+ return kDecimalDigitLimit;
+}
+template <>
+constexpr int DigitLimit<16>() {
+ return kHexadecimalDigitLimit;
+}
+
+template <>
+constexpr int DigitMagnitude<10>() {
+ return 1;
+}
+template <>
+constexpr int DigitMagnitude<16>() {
+ return 4;
+}
+
+// Reads decimal digits from [begin, end) into *out. Returns the number of
+// digits consumed.
+//
+// After max_digits has been read, keeps consuming characters, but no longer
+// adjusts *out. If a nonzero digit is dropped this way, *dropped_nonzero_digit
+// is set; otherwise, it is left unmodified.
+//
+// If no digits are matched, returns 0 and leaves *out unchanged.
+//
+// ConsumeDigits does not protect against overflow on *out; max_digits must
+// be chosen with respect to type T to avoid the possibility of overflow.
+template <int base, typename T>
+std::size_t ConsumeDigits(const char* begin, const char* end, int max_digits,
+ T* out, bool* dropped_nonzero_digit) {
+ if (base == 10) {
+ assert(max_digits <= std::numeric_limits<T>::digits10);
+ } else if (base == 16) {
+ assert(max_digits * 4 <= std::numeric_limits<T>::digits);
+ }
+ const char* const original_begin = begin;
+ T accumulator = *out;
+ const char* significant_digits_end =
+ (end - begin > max_digits) ? begin + max_digits : end;
+ while (begin < significant_digits_end && IsDigit<base>(*begin)) {
+ // Do not guard against *out overflow; max_digits was chosen to avoid this.
+ // Do assert against it, to detect problems in debug builds.
+ auto digit = static_cast<T>(ToDigit<base>(*begin));
+ assert(accumulator * base >= accumulator);
+ accumulator *= base;
+ assert(accumulator + digit >= accumulator);
+ accumulator += digit;
+ ++begin;
+ }
+ bool dropped_nonzero = false;
+ while (begin < end && IsDigit<base>(*begin)) {
+ dropped_nonzero = dropped_nonzero || (*begin != '0');
+ ++begin;
+ }
+ if (dropped_nonzero && dropped_nonzero_digit != nullptr) {
+ *dropped_nonzero_digit = true;
+ }
+ *out = accumulator;
+ return begin - original_begin;
+}
+
+// Returns true if `v` is one of the chars allowed inside parentheses following
+// a NaN.
+bool IsNanChar(char v) {
+ return (v == '_') || (v >= '0' && v <= '9') || (v >= 'a' && v <= 'z') ||
+ (v >= 'A' && v <= 'Z');
+}
+
+// Checks the range [begin, end) for a strtod()-formatted infinity or NaN. If
+// one is found, sets `out` appropriately and returns true.
+bool ParseInfinityOrNan(const char* begin, const char* end,
+ strings_internal::ParsedFloat* out) {
+ if (end - begin < 3) {
+ return false;
+ }
+ switch (*begin) {
+ case 'i':
+ case 'I': {
+ // An infinity std::string consists of the characters "inf" or "infinity",
+ // case insensitive.
+ if (strings_internal::memcasecmp(begin + 1, "nf", 2) != 0) {
+ return false;
+ }
+ out->type = strings_internal::FloatType::kInfinity;
+ if (end - begin >= 8 &&
+ strings_internal::memcasecmp(begin + 3, "inity", 5) == 0) {
+ out->end = begin + 8;
+ } else {
+ out->end = begin + 3;
+ }
+ return true;
+ }
+ case 'n':
+ case 'N': {
+ // A NaN consists of the characters "nan", case insensitive, optionally
+ // followed by a parenthesized sequence of zero or more alphanumeric
+ // characters and/or underscores.
+ if (strings_internal::memcasecmp(begin + 1, "an", 2) != 0) {
+ return false;
+ }
+ out->type = strings_internal::FloatType::kNan;
+ out->end = begin + 3;
+ // NaN is allowed to be followed by a parenthesized std::string, consisting of
+ // only the characters [a-zA-Z0-9_]. Match that if it's present.
+ begin += 3;
+ if (begin < end && *begin == '(') {
+ const char* nan_begin = begin + 1;
+ while (nan_begin < end && IsNanChar(*nan_begin)) {
+ ++nan_begin;
+ }
+ if (nan_begin < end && *nan_begin == ')') {
+ // We found an extra NaN specifier range
+ out->subrange_begin = begin + 1;
+ out->subrange_end = nan_begin;
+ out->end = nan_begin + 1;
+ }
+ }
+ return true;
+ }
+ default:
+ return false;
+ }
+}
+} // namespace
+
+namespace strings_internal {
+
+template <int base>
+strings_internal::ParsedFloat ParseFloat(const char* begin, const char* end,
+ chars_format format_flags) {
+ strings_internal::ParsedFloat result;
+
+ // Exit early if we're given an empty range.
+ if (begin == end) return result;
+
+ // Handle the infinity and NaN cases.
+ if (ParseInfinityOrNan(begin, end, &result)) {
+ return result;
+ }
+
+ const char* const mantissa_begin = begin;
+ while (begin < end && *begin == '0') {
+ ++begin; // skip leading zeros
+ }
+ uint64_t mantissa = 0;
+
+ int exponent_adjustment = 0;
+ bool mantissa_is_inexact = false;
+ std::size_t pre_decimal_digits = ConsumeDigits<base>(
+ begin, end, MantissaDigitsMax<base>(), &mantissa, &mantissa_is_inexact);
+ begin += pre_decimal_digits;
+ int digits_left;
+ if (pre_decimal_digits >= DigitLimit<base>()) {
+ // refuse to parse pathological inputs
+ return result;
+ } else if (pre_decimal_digits > MantissaDigitsMax<base>()) {
+ // We dropped some non-fraction digits on the floor. Adjust our exponent
+ // to compensate.
+ exponent_adjustment =
+ static_cast<int>(pre_decimal_digits - MantissaDigitsMax<base>());
+ digits_left = 0;
+ } else {
+ digits_left =
+ static_cast<int>(MantissaDigitsMax<base>() - pre_decimal_digits);
+ }
+ if (begin < end && *begin == '.') {
+ ++begin;
+ if (mantissa == 0) {
+ // If we haven't seen any nonzero digits yet, keep skipping zeros. We
+ // have to adjust the exponent to reflect the changed place value.
+ const char* begin_zeros = begin;
+ while (begin < end && *begin == '0') {
+ ++begin;
+ }
+ std::size_t zeros_skipped = begin - begin_zeros;
+ if (zeros_skipped >= DigitLimit<base>()) {
+ // refuse to parse pathological inputs
+ return result;
+ }
+ exponent_adjustment -= static_cast<int>(zeros_skipped);
+ }
+ std::size_t post_decimal_digits = ConsumeDigits<base>(
+ begin, end, digits_left, &mantissa, &mantissa_is_inexact);
+ begin += post_decimal_digits;
+
+ // Since `mantissa` is an integer, each significant digit we read after
+ // the decimal point requires an adjustment to the exponent. "1.23e0" will
+ // be stored as `mantissa` == 123 and `exponent` == -2 (that is,
+ // "123e-2").
+ if (post_decimal_digits >= DigitLimit<base>()) {
+ // refuse to parse pathological inputs
+ return result;
+ } else if (post_decimal_digits > digits_left) {
+ exponent_adjustment -= digits_left;
+ } else {
+ exponent_adjustment -= post_decimal_digits;
+ }
+ }
+ // If we've found no mantissa whatsoever, this isn't a number.
+ if (mantissa_begin == begin) {
+ return result;
+ }
+ // A bare "." doesn't count as a mantissa either.
+ if (begin - mantissa_begin == 1 && *mantissa_begin == '.') {
+ return result;
+ }
+
+ if (mantissa_is_inexact) {
+ // We dropped significant digits on the floor. Handle this appropriately.
+ if (base == 10) {
+ // If we truncated significant decimal digits, store the full range of the
+ // mantissa for future big integer math for exact rounding.
+ result.subrange_begin = mantissa_begin;
+ result.subrange_end = begin;
+ } else if (base == 16) {
+ // If we truncated hex digits, reflect this fact by setting the low
+ // ("sticky") bit. This allows for correct rounding in all cases.
+ mantissa |= 1;
+ }
+ }
+ result.mantissa = mantissa;
+
+ const char* const exponent_begin = begin;
+ result.literal_exponent = 0;
+ bool found_exponent = false;
+ if (AllowExponent(format_flags) && begin < end &&
+ IsExponentCharacter<base>(*begin)) {
+ bool negative_exponent = false;
+ ++begin;
+ if (begin < end && *begin == '-') {
+ negative_exponent = true;
+ ++begin;
+ } else if (begin < end && *begin == '+') {
+ ++begin;
+ }
+ const char* const exponent_digits_begin = begin;
+ // Exponent is always expressed in decimal, even for hexadecimal floats.
+ begin += ConsumeDigits<10>(begin, end, kDecimalExponentDigitsMax,
+ &result.literal_exponent, nullptr);
+ if (begin == exponent_digits_begin) {
+ // there were no digits where we expected an exponent. We failed to read
+ // an exponent and should not consume the 'e' after all. Rewind 'begin'.
+ found_exponent = false;
+ begin = exponent_begin;
+ } else {
+ found_exponent = true;
+ if (negative_exponent) {
+ result.literal_exponent = -result.literal_exponent;
+ }
+ }
+ }
+
+ if (!found_exponent && RequireExponent(format_flags)) {
+ // Provided flags required an exponent, but none was found. This results
+ // in a failure to scan.
+ return result;
+ }
+
+ // Success!
+ result.type = strings_internal::FloatType::kNumber;
+ if (result.mantissa > 0) {
+ result.exponent = result.literal_exponent +
+ (DigitMagnitude<base>() * exponent_adjustment);
+ } else {
+ result.exponent = 0;
+ }
+ result.end = begin;
+ return result;
+}
+
+template ParsedFloat ParseFloat<10>(const char* begin, const char* end,
+ chars_format format_flags);
+template ParsedFloat ParseFloat<16>(const char* begin, const char* end,
+ chars_format format_flags);
+
+} // namespace strings_internal
+} // namespace absl
diff --git a/absl/strings/internal/charconv_parse.h b/absl/strings/internal/charconv_parse.h
new file mode 100644
index 0000000..44d06b2
--- /dev/null
+++ b/absl/strings/internal/charconv_parse.h
@@ -0,0 +1,96 @@
+// Copyright 2018 The Abseil Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef ABSL_STRINGS_INTERNAL_CHARCONV_PARSE_H_
+#define ABSL_STRINGS_INTERNAL_CHARCONV_PARSE_H_
+
+#include <cstdint>
+
+#include "absl/strings/charconv.h"
+
+namespace absl {
+namespace strings_internal {
+
+// Enum indicating whether a parsed float is a number or special value.
+enum class FloatType { kNumber, kInfinity, kNan };
+
+// The decomposed parts of a parsed `float` or `double`.
+struct ParsedFloat {
+ // Representation of the parsed mantissa, with the decimal point adjusted to
+ // make it an integer.
+ //
+ // During decimal scanning, this contains 19 significant digits worth of
+ // mantissa value. If digits beyond this point are found, they
+ // are truncated, and if any of these dropped digits are nonzero, then
+ // `mantissa` is inexact, and the full mantissa is stored in [subrange_begin,
+ // subrange_end).
+ //
+ // During hexadecimal scanning, this contains 15 significant hex digits worth
+ // of mantissa value. Digits beyond this point are sticky -- they are
+ // truncated, but if any dropped digits are nonzero, the low bit of mantissa
+ // will be set. (This allows for precise rounding, and avoids the need
+ // to store the full mantissa in [subrange_begin, subrange_end).)
+ uint64_t mantissa = 0;
+
+ // Floating point expontent. This reflects any decimal point adjustments and
+ // any truncated digits from the mantissa. The absolute value of the parsed
+ // number is represented by mantissa * (base ** exponent), where base==10 for
+ // decimal floats, and base==2 for hexadecimal floats.
+ int exponent = 0;
+
+ // The literal exponent value scanned from the input, or 0 if none was
+ // present. This does not reflect any adjustments applied to mantissa.
+ int literal_exponent = 0;
+
+ // The type of number scanned.
+ FloatType type = FloatType::kNumber;
+
+ // When non-null, [subrange_begin, subrange_end) marks a range of characters
+ // that require further processing. The meaning is dependent on float type.
+ // If type == kNumber and this is set, this is a "wide input": the input
+ // mantissa contained more than 19 digits. The range contains the full
+ // mantissa. It plus `literal_exponent` need to be examined to find the best
+ // floating point match.
+ // If type == kNan and this is set, the range marks the contents of a
+ // matched parenthesized character region after the NaN.
+ const char* subrange_begin = nullptr;
+ const char* subrange_end = nullptr;
+
+ // One-past-the-end of the successfully parsed region, or nullptr if no
+ // matching pattern was found.
+ const char* end = nullptr;
+};
+
+// Read the floating point number in the provided range, and populate
+// ParsedFloat accordingly.
+//
+// format_flags is a bitmask value specifying what patterns this API will match.
+// `scientific` and `fixed` are honored per std::from_chars rules
+// ([utility.from.chars], C++17): if exactly one of these bits is set, then an
+// exponent is required, or dislallowed, respectively.
+//
+// Template parameter `base` must be either 10 or 16. For base 16, a "0x" is
+// *not* consumed. The `hex` bit from format_flags is ignored by ParseFloat.
+template <int base>
+ParsedFloat ParseFloat(const char* begin, const char* end,
+ absl::chars_format format_flags);
+
+extern template ParsedFloat ParseFloat<10>(const char* begin, const char* end,
+ absl::chars_format format_flags);
+extern template ParsedFloat ParseFloat<16>(const char* begin, const char* end,
+ absl::chars_format format_flags);
+
+} // namespace strings_internal
+} // namespace absl
+#endif // ABSL_STRINGS_INTERNAL_CHARCONV_PARSE_H_
diff --git a/absl/strings/internal/charconv_parse_test.cc b/absl/strings/internal/charconv_parse_test.cc
new file mode 100644
index 0000000..9511c98
--- /dev/null
+++ b/absl/strings/internal/charconv_parse_test.cc
@@ -0,0 +1,357 @@
+// Copyright 2018 The Abseil Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include "absl/strings/internal/charconv_parse.h"
+
+#include <string>
+#include <utility>
+
+#include "gmock/gmock.h"
+#include "gtest/gtest.h"
+#include "absl/base/internal/raw_logging.h"
+#include "absl/strings/str_cat.h"
+
+using absl::chars_format;
+using absl::strings_internal::FloatType;
+using absl::strings_internal::ParsedFloat;
+using absl::strings_internal::ParseFloat;
+
+namespace {
+
+// Check that a given string input is parsed to the expected mantissa and
+// exponent.
+//
+// Input string `s` must contain a '$' character. It marks the end of the
+// characters that should be consumed by the match. It is stripped from the
+// input to ParseFloat.
+//
+// If input string `s` contains '[' and ']' characters, these mark the region
+// of characters that should be marked as the "subrange". For NaNs, this is
+// the location of the extended NaN string. For numbers, this is the location
+// of the full, over-large mantissa.
+template <int base>
+void ExpectParsedFloat(std::string s, absl::chars_format format_flags,
+ FloatType expected_type, uint64_t expected_mantissa,
+ int expected_exponent,
+ int expected_literal_exponent = -999) {
+ SCOPED_TRACE(s);
+
+ int begin_subrange = -1;
+ int end_subrange = -1;
+ // If s contains '[' and ']', then strip these characters and set the subrange
+ // indices appropriately.
+ std::string::size_type open_bracket_pos = s.find('[');
+ if (open_bracket_pos != std::string::npos) {
+ begin_subrange = static_cast<int>(open_bracket_pos);
+ s.replace(open_bracket_pos, 1, "");
+ std::string::size_type close_bracket_pos = s.find(']');
+ ABSL_RAW_CHECK(close_bracket_pos != absl::string_view::npos,
+ "Test input contains [ without matching ]");
+ end_subrange = static_cast<int>(close_bracket_pos);
+ s.replace(close_bracket_pos, 1, "");
+ }
+ const std::string::size_type expected_characters_matched = s.find('$');
+ ABSL_RAW_CHECK(expected_characters_matched != std::string::npos,
+ "Input std::string must contain $");
+ s.replace(expected_characters_matched, 1, "");
+
+ ParsedFloat parsed =
+ ParseFloat<base>(s.data(), s.data() + s.size(), format_flags);
+
+ EXPECT_NE(parsed.end, nullptr);
+ if (parsed.end == nullptr) {
+ return; // The following tests are not useful if we fully failed to parse
+ }
+ EXPECT_EQ(parsed.type, expected_type);
+ if (begin_subrange == -1) {
+ EXPECT_EQ(parsed.subrange_begin, nullptr);
+ EXPECT_EQ(parsed.subrange_end, nullptr);
+ } else {
+ EXPECT_EQ(parsed.subrange_begin, s.data() + begin_subrange);
+ EXPECT_EQ(parsed.subrange_end, s.data() + end_subrange);
+ }
+ if (parsed.type == FloatType::kNumber) {
+ EXPECT_EQ(parsed.mantissa, expected_mantissa);
+ EXPECT_EQ(parsed.exponent, expected_exponent);
+ if (expected_literal_exponent != -999) {
+ EXPECT_EQ(parsed.literal_exponent, expected_literal_exponent);
+ }
+ }
+ auto characters_matched = static_cast<int>(parsed.end - s.data());
+ EXPECT_EQ(characters_matched, expected_characters_matched);
+}
+
+// Check that a given string input is parsed to the expected mantissa and
+// exponent.
+//
+// Input string `s` must contain a '$' character. It marks the end of the
+// characters that were consumed by the match.
+template <int base>
+void ExpectNumber(std::string s, absl::chars_format format_flags,
+ uint64_t expected_mantissa, int expected_exponent,
+ int expected_literal_exponent = -999) {
+ ExpectParsedFloat<base>(std::move(s), format_flags, FloatType::kNumber,
+ expected_mantissa, expected_exponent,
+ expected_literal_exponent);
+}
+
+// Check that a given string input is parsed to the given special value.
+//
+// This tests against both number bases, since infinities and NaNs have
+// identical representations in both modes.
+void ExpectSpecial(const std::string& s, absl::chars_format format_flags,
+ FloatType type) {
+ ExpectParsedFloat<10>(s, format_flags, type, 0, 0);
+ ExpectParsedFloat<16>(s, format_flags, type, 0, 0);
+}
+
+// Check that a given input string is not matched by Float.
+template <int base>
+void ExpectFailedParse(absl::string_view s, absl::chars_format format_flags) {
+ ParsedFloat parsed =
+ ParseFloat<base>(s.data(), s.data() + s.size(), format_flags);
+ EXPECT_EQ(parsed.end, nullptr);
+}
+
+TEST(ParseFloat, SimpleValue) {
+ // Test that various forms of floating point numbers all parse correctly.
+ ExpectNumber<10>("1.23456789e5$", chars_format::general, 123456789, -3);
+ ExpectNumber<10>("1.23456789e+5$", chars_format::general, 123456789, -3);
+ ExpectNumber<10>("1.23456789E5$", chars_format::general, 123456789, -3);
+ ExpectNumber<10>("1.23456789e05$", chars_format::general, 123456789, -3);
+ ExpectNumber<10>("123.456789e3$", chars_format::general, 123456789, -3);
+ ExpectNumber<10>("0.000123456789e9$", chars_format::general, 123456789, -3);
+ ExpectNumber<10>("123456.789$", chars_format::general, 123456789, -3);
+ ExpectNumber<10>("123456789e-3$", chars_format::general, 123456789, -3);
+
+ ExpectNumber<16>("1.234abcdefp28$", chars_format::general, 0x1234abcdef, -8);
+ ExpectNumber<16>("1.234abcdefp+28$", chars_format::general, 0x1234abcdef, -8);
+ ExpectNumber<16>("1.234ABCDEFp28$", chars_format::general, 0x1234abcdef, -8);
+ ExpectNumber<16>("1.234AbCdEfP0028$", chars_format::general, 0x1234abcdef,
+ -8);
+ ExpectNumber<16>("123.4abcdefp20$", chars_format::general, 0x1234abcdef, -8);
+ ExpectNumber<16>("0.0001234abcdefp44$", chars_format::general, 0x1234abcdef,
+ -8);
+ ExpectNumber<16>("1234abcd.ef$", chars_format::general, 0x1234abcdef, -8);
+ ExpectNumber<16>("1234abcdefp-8$", chars_format::general, 0x1234abcdef, -8);
+
+ // ExpectNumber does not attempt to drop trailing zeroes.
+ ExpectNumber<10>("0001.2345678900e005$", chars_format::general, 12345678900,
+ -5);
+ ExpectNumber<16>("0001.234abcdef000p28$", chars_format::general,
+ 0x1234abcdef000, -20);
+
+ // Ensure non-matching characters after a number are ignored, even when they
+ // look like potentially matching characters.
+ ExpectNumber<10>("1.23456789e5$ ", chars_format::general, 123456789, -3);
+ ExpectNumber<10>("1.23456789e5$e5e5", chars_format::general, 123456789, -3);
+ ExpectNumber<10>("1.23456789e5$.25", chars_format::general, 123456789, -3);
+ ExpectNumber<10>("1.23456789e5$-", chars_format::general, 123456789, -3);
+ ExpectNumber<10>("1.23456789e5$PUPPERS!!!", chars_format::general, 123456789,
+ -3);
+ ExpectNumber<10>("123456.789$efghij", chars_format::general, 123456789, -3);
+ ExpectNumber<10>("123456.789$e", chars_format::general, 123456789, -3);
+ ExpectNumber<10>("123456.789$p5", chars_format::general, 123456789, -3);
+ ExpectNumber<10>("123456.789$.10", chars_format::general, 123456789, -3);
+
+ ExpectNumber<16>("1.234abcdefp28$ ", chars_format::general, 0x1234abcdef,
+ -8);
+ ExpectNumber<16>("1.234abcdefp28$p28", chars_format::general, 0x1234abcdef,
+ -8);
+ ExpectNumber<16>("1.234abcdefp28$.125", chars_format::general, 0x1234abcdef,
+ -8);
+ ExpectNumber<16>("1.234abcdefp28$-", chars_format::general, 0x1234abcdef, -8);
+ ExpectNumber<16>("1.234abcdefp28$KITTEHS!!!", chars_format::general,
+ 0x1234abcdef, -8);
+ ExpectNumber<16>("1234abcd.ef$ghijk", chars_format::general, 0x1234abcdef,
+ -8);
+ ExpectNumber<16>("1234abcd.ef$p", chars_format::general, 0x1234abcdef, -8);
+ ExpectNumber<16>("1234abcd.ef$.10", chars_format::general, 0x1234abcdef, -8);
+
+ // Ensure we can read a full resolution mantissa without overflow.
+ ExpectNumber<10>("9999999999999999999$", chars_format::general,
+ 9999999999999999999u, 0);
+ ExpectNumber<16>("fffffffffffffff$", chars_format::general,
+ 0xfffffffffffffffu, 0);
+
+ // Check that zero is consistently read.
+ ExpectNumber<10>("0$", chars_format::general, 0, 0);
+ ExpectNumber<16>("0$", chars_format::general, 0, 0);
+ ExpectNumber<10>("000000000000000000000000000000000000000$",
+ chars_format::general, 0, 0);
+ ExpectNumber<16>("000000000000000000000000000000000000000$",
+ chars_format::general, 0, 0);
+ ExpectNumber<10>("0000000000000000000000.000000000000000000$",
+ chars_format::general, 0, 0);
+ ExpectNumber<16>("0000000000000000000000.000000000000000000$",
+ chars_format::general, 0, 0);
+ ExpectNumber<10>("0.00000000000000000000000000000000e123456$",
+ chars_format::general, 0, 0);
+ ExpectNumber<16>("0.00000000000000000000000000000000p123456$",
+ chars_format::general, 0, 0);
+}
+
+TEST(ParseFloat, LargeDecimalMantissa) {
+ // After 19 significant decimal digits in the mantissa, ParsedFloat will
+ // truncate additional digits. We need to test that:
+ // 1) the truncation to 19 digits happens
+ // 2) the returned exponent reflects the dropped significant digits
+ // 3) a correct literal_exponent is set
+ //
+ // If and only if a significant digit is found after 19 digits, then the
+ // entirety of the mantissa in case the exact value is needed to make a
+ // rounding decision. The [ and ] characters below denote where such a
+ // subregion was marked by by ParseFloat. They are not part of the input.
+
+ // Mark a capture group only if a dropped digit is significant (nonzero).
+ ExpectNumber<10>("100000000000000000000000000$", chars_format::general,
+ 1000000000000000000,
+ /* adjusted exponent */ 8);
+
+ ExpectNumber<10>("123456789123456789100000000$", chars_format::general,
+ 1234567891234567891,
+ /* adjusted exponent */ 8);
+
+ ExpectNumber<10>("[123456789123456789123456789]$", chars_format::general,
+ 1234567891234567891,
+ /* adjusted exponent */ 8,
+ /* literal exponent */ 0);
+
+ ExpectNumber<10>("[123456789123456789100000009]$", chars_format::general,
+ 1234567891234567891,
+ /* adjusted exponent */ 8,
+ /* literal exponent */ 0);
+
+ ExpectNumber<10>("[123456789123456789120000000]$", chars_format::general,
+ 1234567891234567891,
+ /* adjusted exponent */ 8,
+ /* literal exponent */ 0);
+
+ // Leading zeroes should not count towards the 19 significant digit limit
+ ExpectNumber<10>("[00000000123456789123456789123456789]$",
+ chars_format::general, 1234567891234567891,
+ /* adjusted exponent */ 8,
+ /* literal exponent */ 0);
+
+ ExpectNumber<10>("00000000123456789123456789100000000$",
+ chars_format::general, 1234567891234567891,
+ /* adjusted exponent */ 8);
+
+ // Truncated digits after the decimal point should not cause a further
+ // exponent adjustment.
+ ExpectNumber<10>("1.234567891234567891e123$", chars_format::general,
+ 1234567891234567891, 105);
+ ExpectNumber<10>("[1.23456789123456789123456789]e123$", chars_format::general,
+ 1234567891234567891,
+ /* adjusted exponent */ 105,
+ /* literal exponent */ 123);
+
+ // Ensure we truncate, and not round. (The from_chars algorithm we use
+ // depends on our guess missing low, if it misses, so we need the rounding
+ // error to be downward.)
+ ExpectNumber<10>("[1999999999999999999999]$", chars_format::general,
+ 1999999999999999999,
+ /* adjusted exponent */ 3,
+ /* literal exponent */ 0);
+}
+
+TEST(ParseFloat, LargeHexadecimalMantissa) {
+ // After 15 significant hex digits in the mantissa, ParsedFloat will treat
+ // additional digits as sticky, We need to test that:
+ // 1) The truncation to 15 digits happens
+ // 2) The returned exponent reflects the dropped significant digits
+ // 3) If a nonzero digit is dropped, the low bit of mantissa is set.
+
+ ExpectNumber<16>("123456789abcdef123456789abcdef$", chars_format::general,
+ 0x123456789abcdef, 60);
+
+ // Leading zeroes should not count towards the 15 significant digit limit
+ ExpectNumber<16>("000000123456789abcdef123456789abcdef$",
+ chars_format::general, 0x123456789abcdef, 60);
+
+ // Truncated digits after the radix point should not cause a further
+ // exponent adjustment.
+ ExpectNumber<16>("1.23456789abcdefp100$", chars_format::general,
+ 0x123456789abcdef, 44);
+ ExpectNumber<16>("1.23456789abcdef123456789abcdefp100$",
+ chars_format::general, 0x123456789abcdef, 44);
+
+ // test sticky digit behavior. The low bit should be set iff any dropped
+ // digit is nonzero.
+ ExpectNumber<16>("123456789abcdee123456789abcdee$", chars_format::general,
+ 0x123456789abcdef, 60);
+ ExpectNumber<16>("123456789abcdee000000000000001$", chars_format::general,
+ 0x123456789abcdef, 60);
+ ExpectNumber<16>("123456789abcdee000000000000000$", chars_format::general,
+ 0x123456789abcdee, 60);
+}
+
+TEST(ParseFloat, ScientificVsFixed) {
+ // In fixed mode, an exponent is never matched (but the remainder of the
+ // number will be matched.)
+ ExpectNumber<10>("1.23456789$e5", chars_format::fixed, 123456789, -8);
+ ExpectNumber<10>("123456.789$", chars_format::fixed, 123456789, -3);
+ ExpectNumber<16>("1.234abcdef$p28", chars_format::fixed, 0x1234abcdef, -36);
+ ExpectNumber<16>("1234abcd.ef$", chars_format::fixed, 0x1234abcdef, -8);
+
+ // In scientific mode, numbers don't match *unless* they have an exponent.
+ ExpectNumber<10>("1.23456789e5$", chars_format::scientific, 123456789, -3);
+ ExpectFailedParse<10>("-123456.789$", chars_format::scientific);
+ ExpectNumber<16>("1.234abcdefp28$", chars_format::scientific, 0x1234abcdef,
+ -8);
+ ExpectFailedParse<16>("1234abcd.ef$", chars_format::scientific);
+}
+
+TEST(ParseFloat, Infinity) {
+ ExpectFailedParse<10>("in", chars_format::general);
+ ExpectFailedParse<16>("in", chars_format::general);
+ ExpectFailedParse<10>("inx", chars_format::general);
+ ExpectFailedParse<16>("inx", chars_format::general);
+ ExpectSpecial("inf$", chars_format::general, FloatType::kInfinity);
+ ExpectSpecial("Inf$", chars_format::general, FloatType::kInfinity);
+ ExpectSpecial("INF$", chars_format::general, FloatType::kInfinity);
+ ExpectSpecial("inf$inite", chars_format::general, FloatType::kInfinity);
+ ExpectSpecial("iNfInItY$", chars_format::general, FloatType::kInfinity);
+ ExpectSpecial("infinity$!!!", chars_format::general, FloatType::kInfinity);
+}
+
+TEST(ParseFloat, NaN) {
+ ExpectFailedParse<10>("na", chars_format::general);
+ ExpectFailedParse<16>("na", chars_format::general);
+ ExpectFailedParse<10>("nah", chars_format::general);
+ ExpectFailedParse<16>("nah", chars_format::general);
+ ExpectSpecial("nan$", chars_format::general, FloatType::kNan);
+ ExpectSpecial("NaN$", chars_format::general, FloatType::kNan);
+ ExpectSpecial("nAn$", chars_format::general, FloatType::kNan);
+ ExpectSpecial("NAN$", chars_format::general, FloatType::kNan);
+ ExpectSpecial("NaN$aNaNaNaNaBatman!", chars_format::general, FloatType::kNan);
+
+ // A parenthesized sequence of the characters [a-zA-Z0-9_] is allowed to
+ // appear after an NaN. Check that this is allowed, and that the correct
+ // characters are grouped.
+ //
+ // (The characters [ and ] in the pattern below delimit the expected matched
+ // subgroup; they are not part of the input passed to ParseFloat.)
+ ExpectSpecial("nan([0xabcdef])$", chars_format::general, FloatType::kNan);
+ ExpectSpecial("nan([0xabcdef])$...", chars_format::general, FloatType::kNan);
+ ExpectSpecial("nan([0xabcdef])$)...", chars_format::general, FloatType::kNan);
+ ExpectSpecial("nan([])$", chars_format::general, FloatType::kNan);
+ ExpectSpecial("nan([aAzZ09_])$", chars_format::general, FloatType::kNan);
+ // If the subgroup contains illegal characters, don't match it at all.
+ ExpectSpecial("nan$(bad-char)", chars_format::general, FloatType::kNan);
+ // Also cope with a missing close paren.
+ ExpectSpecial("nan$(0xabcdef", chars_format::general, FloatType::kNan);
+}
+
+} // namespace
diff --git a/absl/strings/internal/escaping_test_common.h b/absl/strings/internal/escaping_test_common.h
new file mode 100644
index 0000000..bd80303
--- /dev/null
+++ b/absl/strings/internal/escaping_test_common.h
@@ -0,0 +1,131 @@
+// Copyright 2017 The Abseil Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+// This test contains common things needed by both escaping_test.cc and
+// escaping_benchmark.cc.
+
+#ifndef ABSL_STRINGS_INTERNAL_ESCAPING_TEST_COMMON_H_
+#define ABSL_STRINGS_INTERNAL_ESCAPING_TEST_COMMON_H_
+
+#include <array>
+#include "absl/strings/string_view.h"
+
+namespace absl {
+namespace strings_internal {
+
+struct base64_testcase {
+ absl::string_view plaintext;
+ absl::string_view cyphertext;
+};
+
+inline const std::array<base64_testcase, 5>& base64_strings() {
+ static const std::array<base64_testcase, 5> testcase{{
+ // Some google quotes
+ // Cyphertext created with "uuencode (GNU sharutils) 4.6.3"
+ // (Note that we're testing the websafe encoding, though, so if
+ // you add messages, be sure to run "tr -- '+/' '-_'" on the output)
+ { "I was always good at math and science, and I never realized "
+ "that was unusual or somehow undesirable. So one of the things "
+ "I care a lot about is helping to remove that stigma, "
+ "to show girls that you can be feminine, you can like the things "
+ "that girls like, but you can also be really good at technology. "
+ "You can be really good at building things."
+ " - Marissa Meyer, Newsweek, 2010-12-22" "\n",
+
+ "SSB3YXMgYWx3YXlzIGdvb2QgYXQgbWF0aCBhbmQgc2NpZW5jZSwgYW5kIEkg"
+ "bmV2ZXIgcmVhbGl6ZWQgdGhhdCB3YXMgdW51c3VhbCBvciBzb21laG93IHVu"
+ "ZGVzaXJhYmxlLiBTbyBvbmUgb2YgdGhlIHRoaW5ncyBJIGNhcmUgYSBsb3Qg"
+ "YWJvdXQgaXMgaGVscGluZyB0byByZW1vdmUgdGhhdCBzdGlnbWEsIHRvIHNo"
+ "b3cgZ2lybHMgdGhhdCB5b3UgY2FuIGJlIGZlbWluaW5lLCB5b3UgY2FuIGxp"
+ "a2UgdGhlIHRoaW5ncyB0aGF0IGdpcmxzIGxpa2UsIGJ1dCB5b3UgY2FuIGFs"
+ "c28gYmUgcmVhbGx5IGdvb2QgYXQgdGVjaG5vbG9neS4gWW91IGNhbiBiZSBy"
+ "ZWFsbHkgZ29vZCBhdCBidWlsZGluZyB0aGluZ3MuIC0gTWFyaXNzYSBNZXll"
+ "ciwgTmV3c3dlZWssIDIwMTAtMTItMjIK" },
+
+ { "Typical first year for a new cluster: "
+ "~0.5 overheating "
+ "~1 PDU failure "
+ "~1 rack-move "
+ "~1 network rewiring "
+ "~20 rack failures "
+ "~5 racks go wonky "
+ "~8 network maintenances "
+ "~12 router reloads "
+ "~3 router failures "
+ "~dozens of minor 30-second blips for dns "
+ "~1000 individual machine failures "
+ "~thousands of hard drive failures "
+ "slow disks, bad memory, misconfigured machines, flaky machines, etc."
+ " - Jeff Dean, The Joys of Real Hardware" "\n",
+
+ "VHlwaWNhbCBmaXJzdCB5ZWFyIGZvciBhIG5ldyBjbHVzdGVyOiB-MC41IG92"
+ "ZXJoZWF0aW5nIH4xIFBEVSBmYWlsdXJlIH4xIHJhY2stbW92ZSB-MSBuZXR3"
+ "b3JrIHJld2lyaW5nIH4yMCByYWNrIGZhaWx1cmVzIH41IHJhY2tzIGdvIHdv"
+ "bmt5IH44IG5ldHdvcmsgbWFpbnRlbmFuY2VzIH4xMiByb3V0ZXIgcmVsb2Fk"
+ "cyB-MyByb3V0ZXIgZmFpbHVyZXMgfmRvemVucyBvZiBtaW5vciAzMC1zZWNv"
+ "bmQgYmxpcHMgZm9yIGRucyB-MTAwMCBpbmRpdmlkdWFsIG1hY2hpbmUgZmFp"
+ "bHVyZXMgfnRob3VzYW5kcyBvZiBoYXJkIGRyaXZlIGZhaWx1cmVzIHNsb3cg"
+ "ZGlza3MsIGJhZCBtZW1vcnksIG1pc2NvbmZpZ3VyZWQgbWFjaGluZXMsIGZs"
+ "YWt5IG1hY2hpbmVzLCBldGMuIC0gSmVmZiBEZWFuLCBUaGUgSm95cyBvZiBS"
+ "ZWFsIEhhcmR3YXJlCg" },
+
+ { "I'm the head of the webspam team at Google. "
+ "That means that if you type your name into Google and get porn back, "
+ "it's my fault. Unless you're a porn star, in which case porn is a "
+ "completely reasonable response."
+ " - Matt Cutts, Google Plus" "\n",
+
+ "SSdtIHRoZSBoZWFkIG9mIHRoZSB3ZWJzcGFtIHRlYW0gYXQgR29vZ2xlLiAg"
+ "VGhhdCBtZWFucyB0aGF0IGlmIHlvdSB0eXBlIHlvdXIgbmFtZSBpbnRvIEdv"
+ "b2dsZSBhbmQgZ2V0IHBvcm4gYmFjaywgaXQncyBteSBmYXVsdC4gVW5sZXNz"
+ "IHlvdSdyZSBhIHBvcm4gc3RhciwgaW4gd2hpY2ggY2FzZSBwb3JuIGlzIGEg"
+ "Y29tcGxldGVseSByZWFzb25hYmxlIHJlc3BvbnNlLiAtIE1hdHQgQ3V0dHMs"
+ "IEdvb2dsZSBQbHVzCg" },
+
+ { "It will still be a long time before machines approach human "
+ "intelligence. "
+ "But luckily, machines don't actually have to be intelligent; "
+ "they just have to fake it. Access to a wealth of information, "
+ "combined with a rudimentary decision-making capacity, "
+ "can often be almost as useful. Of course, the results are better yet "
+ "when coupled with intelligence. A reference librarian with access to "
+ "a good search engine is a formidable tool."
+ " - Craig Silverstein, Siemens Pictures of the Future, Spring 2004"
+ "\n",
+
+ "SXQgd2lsbCBzdGlsbCBiZSBhIGxvbmcgdGltZSBiZWZvcmUgbWFjaGluZXMg"
+ "YXBwcm9hY2ggaHVtYW4gaW50ZWxsaWdlbmNlLiBCdXQgbHVja2lseSwgbWFj"
+ "aGluZXMgZG9uJ3QgYWN0dWFsbHkgaGF2ZSB0byBiZSBpbnRlbGxpZ2VudDsg"
+ "dGhleSBqdXN0IGhhdmUgdG8gZmFrZSBpdC4gQWNjZXNzIHRvIGEgd2VhbHRo"
+ "IG9mIGluZm9ybWF0aW9uLCBjb21iaW5lZCB3aXRoIGEgcnVkaW1lbnRhcnkg"
+ "ZGVjaXNpb24tbWFraW5nIGNhcGFjaXR5LCBjYW4gb2Z0ZW4gYmUgYWxtb3N0"
+ "IGFzIHVzZWZ1bC4gT2YgY291cnNlLCB0aGUgcmVzdWx0cyBhcmUgYmV0dGVy"
+ "IHlldCB3aGVuIGNvdXBsZWQgd2l0aCBpbnRlbGxpZ2VuY2UuIEEgcmVmZXJl"
+ "bmNlIGxpYnJhcmlhbiB3aXRoIGFjY2VzcyB0byBhIGdvb2Qgc2VhcmNoIGVu"
+ "Z2luZSBpcyBhIGZvcm1pZGFibGUgdG9vbC4gLSBDcmFpZyBTaWx2ZXJzdGVp"
+ "biwgU2llbWVucyBQaWN0dXJlcyBvZiB0aGUgRnV0dXJlLCBTcHJpbmcgMjAw"
+ "NAo" },
+
+ // Degenerate edge case
+ { "",
+ "" },
+ }};
+
+ return testcase;
+}
+
+} // namespace strings_internal
+} // namespace absl
+
+#endif // ABSL_STRINGS_INTERNAL_ESCAPING_TEST_COMMON_H_
diff --git a/absl/strings/internal/memutil.cc b/absl/strings/internal/memutil.cc
new file mode 100644
index 0000000..77aa63c
--- /dev/null
+++ b/absl/strings/internal/memutil.cc
@@ -0,0 +1,110 @@
+// Copyright 2017 The Abseil Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include "absl/strings/internal/memutil.h"
+
+#include <cstdlib>
+
+namespace absl {
+namespace strings_internal {
+
+int memcasecmp(const char* s1, const char* s2, size_t len) {
+ const unsigned char* us1 = reinterpret_cast<const unsigned char*>(s1);
+ const unsigned char* us2 = reinterpret_cast<const unsigned char*>(s2);
+
+ for (size_t i = 0; i < len; i++) {
+ const int diff =
+ int{static_cast<unsigned char>(absl::ascii_tolower(us1[i]))} -
+ int{static_cast<unsigned char>(absl::ascii_tolower(us2[i]))};
+ if (diff != 0) return diff;
+ }
+ return 0;
+}
+
+char* memdup(const char* s, size_t slen) {
+ void* copy;
+ if ((copy = malloc(slen)) == nullptr) return nullptr;
+ memcpy(copy, s, slen);
+ return reinterpret_cast<char*>(copy);
+}
+
+char* memrchr(const char* s, int c, size_t slen) {
+ for (const char* e = s + slen - 1; e >= s; e--) {
+ if (*e == c) return const_cast<char*>(e);
+ }
+ return nullptr;
+}
+
+size_t memspn(const char* s, size_t slen, const char* accept) {
+ const char* p = s;
+ const char* spanp;
+ char c, sc;
+
+cont:
+ c = *p++;
+ if (slen-- == 0) return p - 1 - s;
+ for (spanp = accept; (sc = *spanp++) != '\0';)
+ if (sc == c) goto cont;
+ return p - 1 - s;
+}
+
+size_t memcspn(const char* s, size_t slen, const char* reject) {
+ const char* p = s;
+ const char* spanp;
+ char c, sc;
+
+ while (slen-- != 0) {
+ c = *p++;
+ for (spanp = reject; (sc = *spanp++) != '\0';)
+ if (sc == c) return p - 1 - s;
+ }
+ return p - s;
+}
+
+char* mempbrk(const char* s, size_t slen, const char* accept) {
+ const char* scanp;
+ int sc;
+
+ for (; slen; ++s, --slen) {
+ for (scanp = accept; (sc = *scanp++) != '\0';)
+ if (sc == *s) return const_cast<char*>(s);
+ }
+ return nullptr;
+}
+
+// This is significantly faster for case-sensitive matches with very
+// few possible matches. See unit test for benchmarks.
+const char* memmatch(const char* phaystack, size_t haylen, const char* pneedle,
+ size_t neelen) {
+ if (0 == neelen) {
+ return phaystack; // even if haylen is 0
+ }
+ if (haylen < neelen) return nullptr;
+
+ const char* match;
+ const char* hayend = phaystack + haylen - neelen + 1;
+ // A static cast is used here to work around the fact that memchr returns
+ // a void* on Posix-compliant systems and const void* on Windows.
+ while ((match = static_cast<const char*>(
+ memchr(phaystack, pneedle[0], hayend - phaystack)))) {
+ if (memcmp(match, pneedle, neelen) == 0)
+ return match;
+ else
+ phaystack = match + 1;
+ }
+ return nullptr;
+}
+
+} // namespace strings_internal
+} // namespace absl
diff --git a/absl/strings/internal/memutil.h b/absl/strings/internal/memutil.h
new file mode 100644
index 0000000..7c071a8
--- /dev/null
+++ b/absl/strings/internal/memutil.h
@@ -0,0 +1,146 @@
+//
+// Copyright 2017 The Abseil Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+
+// These routines provide mem versions of standard C string routines,
+// such as strpbrk. They function exactly the same as the str versions,
+// so if you wonder what they are, replace the word "mem" by
+// "str" and check out the man page. I could return void*, as the
+// strutil.h mem*() routines tend to do, but I return char* instead
+// since this is by far the most common way these functions are called.
+//
+// The difference between the mem and str versions is the mem version
+// takes a pointer and a length, rather than a '\0'-terminated string.
+// The memcase* routines defined here assume the locale is "C"
+// (they use absl::ascii_tolower instead of tolower).
+//
+// These routines are based on the BSD library.
+//
+// Here's a list of routines from string.h, and their mem analogues.
+// Functions in lowercase are defined in string.h; those in UPPERCASE
+// are defined here:
+//
+// strlen --
+// strcat strncat MEMCAT
+// strcpy strncpy memcpy
+// -- memccpy (very cool function, btw)
+// -- memmove
+// -- memset
+// strcmp strncmp memcmp
+// strcasecmp strncasecmp MEMCASECMP
+// strchr memchr
+// strcoll --
+// strxfrm --
+// strdup strndup MEMDUP
+// strrchr MEMRCHR
+// strspn MEMSPN
+// strcspn MEMCSPN
+// strpbrk MEMPBRK
+// strstr MEMSTR MEMMEM
+// (g)strcasestr MEMCASESTR MEMCASEMEM
+// strtok --
+// strprefix MEMPREFIX (strprefix is from strutil.h)
+// strcaseprefix MEMCASEPREFIX (strcaseprefix is from strutil.h)
+// strsuffix MEMSUFFIX (strsuffix is from strutil.h)
+// strcasesuffix MEMCASESUFFIX (strcasesuffix is from strutil.h)
+// -- MEMIS
+// -- MEMCASEIS
+// strcount MEMCOUNT (strcount is from strutil.h)
+
+#ifndef ABSL_STRINGS_INTERNAL_MEMUTIL_H_
+#define ABSL_STRINGS_INTERNAL_MEMUTIL_H_
+
+#include <cstddef>
+#include <cstring>
+
+#include "absl/base/port.h" // disable some warnings on Windows
+#include "absl/strings/ascii.h" // for absl::ascii_tolower
+
+namespace absl {
+namespace strings_internal {
+
+inline char* memcat(char* dest, size_t destlen, const char* src,
+ size_t srclen) {
+ return reinterpret_cast<char*>(memcpy(dest + destlen, src, srclen));
+}
+
+int memcasecmp(const char* s1, const char* s2, size_t len);
+char* memdup(const char* s, size_t slen);
+char* memrchr(const char* s, int c, size_t slen);
+size_t memspn(const char* s, size_t slen, const char* accept);
+size_t memcspn(const char* s, size_t slen, const char* reject);
+char* mempbrk(const char* s, size_t slen, const char* accept);
+
+// This is for internal use only. Don't call this directly
+template <bool case_sensitive>
+const char* int_memmatch(const char* haystack, size_t haylen,
+ const char* needle, size_t neelen) {
+ if (0 == neelen) {
+ return haystack; // even if haylen is 0
+ }
+ const char* hayend = haystack + haylen;
+ const char* needlestart = needle;
+ const char* needleend = needlestart + neelen;
+
+ for (; haystack < hayend; ++haystack) {
+ char hay = case_sensitive
+ ? *haystack
+ : absl::ascii_tolower(static_cast<unsigned char>(*haystack));
+ char nee = case_sensitive
+ ? *needle
+ : absl::ascii_tolower(static_cast<unsigned char>(*needle));
+ if (hay == nee) {
+ if (++needle == needleend) {
+ return haystack + 1 - neelen;
+ }
+ } else if (needle != needlestart) {
+ // must back up haystack in case a prefix matched (find "aab" in "aaab")
+ haystack -= needle - needlestart; // for loop will advance one more
+ needle = needlestart;
+ }
+ }
+ return nullptr;
+}
+
+// These are the guys you can call directly
+inline const char* memstr(const char* phaystack, size_t haylen,
+ const char* pneedle) {
+ return int_memmatch<true>(phaystack, haylen, pneedle, strlen(pneedle));
+}
+
+inline const char* memcasestr(const char* phaystack, size_t haylen,
+ const char* pneedle) {
+ return int_memmatch<false>(phaystack, haylen, pneedle, strlen(pneedle));
+}
+
+inline const char* memmem(const char* phaystack, size_t haylen,
+ const char* pneedle, size_t needlelen) {
+ return int_memmatch<true>(phaystack, haylen, pneedle, needlelen);
+}
+
+inline const char* memcasemem(const char* phaystack, size_t haylen,
+ const char* pneedle, size_t needlelen) {
+ return int_memmatch<false>(phaystack, haylen, pneedle, needlelen);
+}
+
+// This is significantly faster for case-sensitive matches with very
+// few possible matches. See unit test for benchmarks.
+const char* memmatch(const char* phaystack, size_t haylen, const char* pneedle,
+ size_t neelen);
+
+} // namespace strings_internal
+} // namespace absl
+
+#endif // ABSL_STRINGS_INTERNAL_MEMUTIL_H_
diff --git a/absl/strings/internal/memutil_benchmark.cc b/absl/strings/internal/memutil_benchmark.cc
new file mode 100644
index 0000000..dc95c3e
--- /dev/null
+++ b/absl/strings/internal/memutil_benchmark.cc
@@ -0,0 +1,323 @@
+// Copyright 2018 The Abseil Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include "absl/strings/internal/memutil.h"
+
+#include <algorithm>
+#include <cstdlib>
+
+#include "benchmark/benchmark.h"
+#include "absl/strings/ascii.h"
+
+// We fill the haystack with aaaaaaaaaaaaaaaaaa...aaaab.
+// That gives us:
+// - an easy search: 'b'
+// - a medium search: 'ab'. That means every letter is a possible match.
+// - a pathological search: 'aaaaaa.......aaaaab' (half as many a's as haytack)
+// We benchmark case-sensitive and case-insensitive versions of
+// three memmem implementations:
+// - memmem() from memutil.h
+// - search() from STL
+// - memmatch(), a custom implementation using memchr and memcmp.
+// Here are sample results:
+//
+// Run on (12 X 3800 MHz CPU s)
+// CPU Caches:
+// L1 Data 32K (x6)
+// L1 Instruction 32K (x6)
+// L2 Unified 256K (x6)
+// L3 Unified 15360K (x1)
+// ----------------------------------------------------------------
+// Benchmark Time CPU Iterations
+// ----------------------------------------------------------------
+// BM_Memmem 3583 ns 3582 ns 196469 2.59966GB/s
+// BM_MemmemMedium 13743 ns 13742 ns 50901 693.986MB/s
+// BM_MemmemPathological 13695030 ns 13693977 ns 51 713.133kB/s
+// BM_Memcasemem 3299 ns 3299 ns 212942 2.82309GB/s
+// BM_MemcasememMedium 16407 ns 16406 ns 42170 581.309MB/s
+// BM_MemcasememPathological 17267745 ns 17266030 ns 41 565.598kB/s
+// BM_Search 1610 ns 1609 ns 431321 5.78672GB/s
+// BM_SearchMedium 11111 ns 11110 ns 63001 858.414MB/s
+// BM_SearchPathological 12117390 ns 12116397 ns 58 805.984kB/s
+// BM_Searchcase 3081 ns 3081 ns 229949 3.02313GB/s
+// BM_SearchcaseMedium 16003 ns 16001 ns 44170 595.998MB/s
+// BM_SearchcasePathological 15823413 ns 15821909 ns 44 617.222kB/s
+// BM_Memmatch 197 ns 197 ns 3584225 47.2951GB/s
+// BM_MemmatchMedium 52333 ns 52329 ns 13280 182.244MB/s
+// BM_MemmatchPathological 659799 ns 659727 ns 1058 14.4556MB/s
+// BM_Memcasematch 5460 ns 5460 ns 127606 1.70586GB/s
+// BM_MemcasematchMedium 32861 ns 32857 ns 21258 290.248MB/s
+// BM_MemcasematchPathological 15154243 ns 15153089 ns 46 644.464kB/s
+// BM_MemmemStartup 5 ns 5 ns 150821500
+// BM_SearchStartup 5 ns 5 ns 150644203
+// BM_MemmatchStartup 7 ns 7 ns 97068802
+//
+// Conclusions:
+//
+// The following recommendations are based on the sample results above. However,
+// we have found that the performance of STL search can vary significantly
+// depending on compiler and standard library implementation. We recommend you
+// run the benchmarks for yourself on relevant platforms.
+//
+// If you need case-insensitive, STL search is slightly better than memmem for
+// all cases.
+//
+// Case-sensitive is more subtle:
+// Custom memmatch is _very_ fast at scanning, so if you have very few possible
+// matches in your haystack, that's the way to go. Performance drops
+// significantly with more matches.
+//
+// STL search is slightly faster than memmem in the medium and pathological
+// benchmarks. However, the performance of memmem is currently more dependable
+// across platforms and build configurations.
+
+namespace {
+
+constexpr int kHaystackSize = 10000;
+constexpr int64_t kHaystackSize64 = kHaystackSize;
+const char* MakeHaystack() {
+ char* haystack = new char[kHaystackSize];
+ for (int i = 0; i < kHaystackSize - 1; ++i) haystack[i] = 'a';
+ haystack[kHaystackSize - 1] = 'b';
+ return haystack;
+}
+const char* const kHaystack = MakeHaystack();
+
+void BM_Memmem(benchmark::State& state) {
+ for (auto _ : state) {
+ benchmark::DoNotOptimize(
+ absl::strings_internal::memmem(kHaystack, kHaystackSize, "b", 1));
+ }
+ state.SetBytesProcessed(kHaystackSize64 * state.iterations());
+}
+BENCHMARK(BM_Memmem);
+
+void BM_MemmemMedium(benchmark::State& state) {
+ for (auto _ : state) {
+ benchmark::DoNotOptimize(
+ absl::strings_internal::memmem(kHaystack, kHaystackSize, "ab", 2));
+ }
+ state.SetBytesProcessed(kHaystackSize64 * state.iterations());
+}
+BENCHMARK(BM_MemmemMedium);
+
+void BM_MemmemPathological(benchmark::State& state) {
+ for (auto _ : state) {
+ benchmark::DoNotOptimize(absl::strings_internal::memmem(
+ kHaystack, kHaystackSize, kHaystack + kHaystackSize / 2,
+ kHaystackSize - kHaystackSize / 2));
+ }
+ state.SetBytesProcessed(kHaystackSize64 * state.iterations());
+}
+BENCHMARK(BM_MemmemPathological);
+
+void BM_Memcasemem(benchmark::State& state) {
+ for (auto _ : state) {
+ benchmark::DoNotOptimize(
+ absl::strings_internal::memcasemem(kHaystack, kHaystackSize, "b", 1));
+ }
+ state.SetBytesProcessed(kHaystackSize64 * state.iterations());
+}
+BENCHMARK(BM_Memcasemem);
+
+void BM_MemcasememMedium(benchmark::State& state) {
+ for (auto _ : state) {
+ benchmark::DoNotOptimize(
+ absl::strings_internal::memcasemem(kHaystack, kHaystackSize, "ab", 2));
+ }
+ state.SetBytesProcessed(kHaystackSize64 * state.iterations());
+}
+BENCHMARK(BM_MemcasememMedium);
+
+void BM_MemcasememPathological(benchmark::State& state) {
+ for (auto _ : state) {
+ benchmark::DoNotOptimize(absl::strings_internal::memcasemem(
+ kHaystack, kHaystackSize, kHaystack + kHaystackSize / 2,
+ kHaystackSize - kHaystackSize / 2));
+ }
+ state.SetBytesProcessed(kHaystackSize64 * state.iterations());
+}
+BENCHMARK(BM_MemcasememPathological);
+
+bool case_eq(const char a, const char b) {
+ return absl::ascii_tolower(a) == absl::ascii_tolower(b);
+}
+
+void BM_Search(benchmark::State& state) {
+ for (auto _ : state) {
+ benchmark::DoNotOptimize(std::search(kHaystack, kHaystack + kHaystackSize,
+ kHaystack + kHaystackSize - 1,
+ kHaystack + kHaystackSize));
+ }
+ state.SetBytesProcessed(kHaystackSize64 * state.iterations());
+}
+BENCHMARK(BM_Search);
+
+void BM_SearchMedium(benchmark::State& state) {
+ for (auto _ : state) {
+ benchmark::DoNotOptimize(std::search(kHaystack, kHaystack + kHaystackSize,
+ kHaystack + kHaystackSize - 2,
+ kHaystack + kHaystackSize));
+ }
+ state.SetBytesProcessed(kHaystackSize64 * state.iterations());
+}
+BENCHMARK(BM_SearchMedium);
+
+void BM_SearchPathological(benchmark::State& state) {
+ for (auto _ : state) {
+ benchmark::DoNotOptimize(std::search(kHaystack, kHaystack + kHaystackSize,
+ kHaystack + kHaystackSize / 2,
+ kHaystack + kHaystackSize));
+ }
+ state.SetBytesProcessed(kHaystackSize64 * state.iterations());
+}
+BENCHMARK(BM_SearchPathological);
+
+void BM_Searchcase(benchmark::State& state) {
+ for (auto _ : state) {
+ benchmark::DoNotOptimize(std::search(kHaystack, kHaystack + kHaystackSize,
+ kHaystack + kHaystackSize - 1,
+ kHaystack + kHaystackSize, case_eq));
+ }
+ state.SetBytesProcessed(kHaystackSize64 * state.iterations());
+}
+BENCHMARK(BM_Searchcase);
+
+void BM_SearchcaseMedium(benchmark::State& state) {
+ for (auto _ : state) {
+ benchmark::DoNotOptimize(std::search(kHaystack, kHaystack + kHaystackSize,
+ kHaystack + kHaystackSize - 2,
+ kHaystack + kHaystackSize, case_eq));
+ }
+ state.SetBytesProcessed(kHaystackSize64 * state.iterations());
+}
+BENCHMARK(BM_SearchcaseMedium);
+
+void BM_SearchcasePathological(benchmark::State& state) {
+ for (auto _ : state) {
+ benchmark::DoNotOptimize(std::search(kHaystack, kHaystack + kHaystackSize,
+ kHaystack + kHaystackSize / 2,
+ kHaystack + kHaystackSize, case_eq));
+ }
+ state.SetBytesProcessed(kHaystackSize64 * state.iterations());
+}
+BENCHMARK(BM_SearchcasePathological);
+
+char* memcasechr(const char* s, int c, size_t slen) {
+ c = absl::ascii_tolower(c);
+ for (; slen; ++s, --slen) {
+ if (absl::ascii_tolower(*s) == c) return const_cast<char*>(s);
+ }
+ return nullptr;
+}
+
+const char* memcasematch(const char* phaystack, size_t haylen,
+ const char* pneedle, size_t neelen) {
+ if (0 == neelen) {
+ return phaystack; // even if haylen is 0
+ }
+ if (haylen < neelen) return nullptr;
+
+ const char* match;
+ const char* hayend = phaystack + haylen - neelen + 1;
+ while ((match = static_cast<char*>(
+ memcasechr(phaystack, pneedle[0], hayend - phaystack)))) {
+ if (absl::strings_internal::memcasecmp(match, pneedle, neelen) == 0)
+ return match;
+ else
+ phaystack = match + 1;
+ }
+ return nullptr;
+}
+
+void BM_Memmatch(benchmark::State& state) {
+ for (auto _ : state) {
+ benchmark::DoNotOptimize(
+ absl::strings_internal::memmatch(kHaystack, kHaystackSize, "b", 1));
+ }
+ state.SetBytesProcessed(kHaystackSize64 * state.iterations());
+}
+BENCHMARK(BM_Memmatch);
+
+void BM_MemmatchMedium(benchmark::State& state) {
+ for (auto _ : state) {
+ benchmark::DoNotOptimize(
+ absl::strings_internal::memmatch(kHaystack, kHaystackSize, "ab", 2));
+ }
+ state.SetBytesProcessed(kHaystackSize64 * state.iterations());
+}
+BENCHMARK(BM_MemmatchMedium);
+
+void BM_MemmatchPathological(benchmark::State& state) {
+ for (auto _ : state) {
+ benchmark::DoNotOptimize(absl::strings_internal::memmatch(
+ kHaystack, kHaystackSize, kHaystack + kHaystackSize / 2,
+ kHaystackSize - kHaystackSize / 2));
+ }
+ state.SetBytesProcessed(kHaystackSize64 * state.iterations());
+}
+BENCHMARK(BM_MemmatchPathological);
+
+void BM_Memcasematch(benchmark::State& state) {
+ for (auto _ : state) {
+ benchmark::DoNotOptimize(memcasematch(kHaystack, kHaystackSize, "b", 1));
+ }
+ state.SetBytesProcessed(kHaystackSize64 * state.iterations());
+}
+BENCHMARK(BM_Memcasematch);
+
+void BM_MemcasematchMedium(benchmark::State& state) {
+ for (auto _ : state) {
+ benchmark::DoNotOptimize(memcasematch(kHaystack, kHaystackSize, "ab", 2));
+ }
+ state.SetBytesProcessed(kHaystackSize64 * state.iterations());
+}
+BENCHMARK(BM_MemcasematchMedium);
+
+void BM_MemcasematchPathological(benchmark::State& state) {
+ for (auto _ : state) {
+ benchmark::DoNotOptimize(memcasematch(kHaystack, kHaystackSize,
+ kHaystack + kHaystackSize / 2,
+ kHaystackSize - kHaystackSize / 2));
+ }
+ state.SetBytesProcessed(kHaystackSize64 * state.iterations());
+}
+BENCHMARK(BM_MemcasematchPathological);
+
+void BM_MemmemStartup(benchmark::State& state) {
+ for (auto _ : state) {
+ benchmark::DoNotOptimize(absl::strings_internal::memmem(
+ kHaystack + kHaystackSize - 10, 10, kHaystack + kHaystackSize - 1, 1));
+ }
+}
+BENCHMARK(BM_MemmemStartup);
+
+void BM_SearchStartup(benchmark::State& state) {
+ for (auto _ : state) {
+ benchmark::DoNotOptimize(
+ std::search(kHaystack + kHaystackSize - 10, kHaystack + kHaystackSize,
+ kHaystack + kHaystackSize - 1, kHaystack + kHaystackSize));
+ }
+}
+BENCHMARK(BM_SearchStartup);
+
+void BM_MemmatchStartup(benchmark::State& state) {
+ for (auto _ : state) {
+ benchmark::DoNotOptimize(absl::strings_internal::memmatch(
+ kHaystack + kHaystackSize - 10, 10, kHaystack + kHaystackSize - 1, 1));
+ }
+}
+BENCHMARK(BM_MemmatchStartup);
+
+} // namespace
diff --git a/absl/strings/internal/memutil_test.cc b/absl/strings/internal/memutil_test.cc
new file mode 100644
index 0000000..d8681dd
--- /dev/null
+++ b/absl/strings/internal/memutil_test.cc
@@ -0,0 +1,179 @@
+// Copyright 2017 The Abseil Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Unit test for memutil.cc
+
+#include "absl/strings/internal/memutil.h"
+
+#include <cstdlib>
+
+#include "gtest/gtest.h"
+#include "absl/strings/ascii.h"
+
+namespace {
+
+static char* memcasechr(const char* s, int c, size_t slen) {
+ c = absl::ascii_tolower(c);
+ for (; slen; ++s, --slen) {
+ if (absl::ascii_tolower(*s) == c) return const_cast<char*>(s);
+ }
+ return nullptr;
+}
+
+static const char* memcasematch(const char* phaystack, size_t haylen,
+ const char* pneedle, size_t neelen) {
+ if (0 == neelen) {
+ return phaystack; // even if haylen is 0
+ }
+ if (haylen < neelen) return nullptr;
+
+ const char* match;
+ const char* hayend = phaystack + haylen - neelen + 1;
+ while ((match = static_cast<char*>(
+ memcasechr(phaystack, pneedle[0], hayend - phaystack)))) {
+ if (absl::strings_internal::memcasecmp(match, pneedle, neelen) == 0)
+ return match;
+ else
+ phaystack = match + 1;
+ }
+ return nullptr;
+}
+
+TEST(MemUtilTest, AllTests) {
+ // check memutil functions
+ char a[1000];
+ absl::strings_internal::memcat(a, 0, "hello", sizeof("hello") - 1);
+ absl::strings_internal::memcat(a, 5, " there", sizeof(" there") - 1);
+
+ EXPECT_EQ(absl::strings_internal::memcasecmp(a, "heLLO there",
+ sizeof("hello there") - 1),
+ 0);
+ EXPECT_EQ(absl::strings_internal::memcasecmp(a, "heLLO therf",
+ sizeof("hello there") - 1),
+ -1);
+ EXPECT_EQ(absl::strings_internal::memcasecmp(a, "heLLO therf",
+ sizeof("hello there") - 2),
+ 0);
+ EXPECT_EQ(absl::strings_internal::memcasecmp(a, "whatever", 0), 0);
+
+ char* p = absl::strings_internal::memdup("hello", 5);
+ free(p);
+
+ p = absl::strings_internal::memrchr("hello there", 'e',
+ sizeof("hello there") - 1);
+ EXPECT_TRUE(p && p[-1] == 'r');
+ p = absl::strings_internal::memrchr("hello there", 'e',
+ sizeof("hello there") - 2);
+ EXPECT_TRUE(p && p[-1] == 'h');
+ p = absl::strings_internal::memrchr("hello there", 'u',
+ sizeof("hello there") - 1);
+ EXPECT_TRUE(p == nullptr);
+
+ int len = absl::strings_internal::memspn("hello there",
+ sizeof("hello there") - 1, "hole");
+ EXPECT_EQ(len, sizeof("hello") - 1);
+ len = absl::strings_internal::memspn("hello there", sizeof("hello there") - 1,
+ "u");
+ EXPECT_EQ(len, 0);
+ len = absl::strings_internal::memspn("hello there", sizeof("hello there") - 1,
+ "");
+ EXPECT_EQ(len, 0);
+ len = absl::strings_internal::memspn("hello there", sizeof("hello there") - 1,
+ "trole h");
+ EXPECT_EQ(len, sizeof("hello there") - 1);
+ len = absl::strings_internal::memspn("hello there!",
+ sizeof("hello there!") - 1, "trole h");
+ EXPECT_EQ(len, sizeof("hello there") - 1);
+ len = absl::strings_internal::memspn("hello there!",
+ sizeof("hello there!") - 2, "trole h!");
+ EXPECT_EQ(len, sizeof("hello there!") - 2);
+
+ len = absl::strings_internal::memcspn("hello there",
+ sizeof("hello there") - 1, "leho");
+ EXPECT_EQ(len, 0);
+ len = absl::strings_internal::memcspn("hello there",
+ sizeof("hello there") - 1, "u");
+ EXPECT_EQ(len, sizeof("hello there") - 1);
+ len = absl::strings_internal::memcspn("hello there",
+ sizeof("hello there") - 1, "");
+ EXPECT_EQ(len, sizeof("hello there") - 1);
+ len = absl::strings_internal::memcspn("hello there",
+ sizeof("hello there") - 1, " ");
+ EXPECT_EQ(len, 5);
+
+ p = absl::strings_internal::mempbrk("hello there", sizeof("hello there") - 1,
+ "leho");
+ EXPECT_TRUE(p && p[1] == 'e' && p[2] == 'l');
+ p = absl::strings_internal::mempbrk("hello there", sizeof("hello there") - 1,
+ "nu");
+ EXPECT_TRUE(p == nullptr);
+ p = absl::strings_internal::mempbrk("hello there!",
+ sizeof("hello there!") - 2, "!");
+ EXPECT_TRUE(p == nullptr);
+ p = absl::strings_internal::mempbrk("hello there", sizeof("hello there") - 1,
+ " t ");
+ EXPECT_TRUE(p && p[-1] == 'o' && p[1] == 't');
+
+ {
+ const char kHaystack[] = "0123456789";
+ EXPECT_EQ(absl::strings_internal::memmem(kHaystack, 0, "", 0), kHaystack);
+ EXPECT_EQ(absl::strings_internal::memmem(kHaystack, 10, "012", 3),
+ kHaystack);
+ EXPECT_EQ(absl::strings_internal::memmem(kHaystack, 10, "0xx", 1),
+ kHaystack);
+ EXPECT_EQ(absl::strings_internal::memmem(kHaystack, 10, "789", 3),
+ kHaystack + 7);
+ EXPECT_EQ(absl::strings_internal::memmem(kHaystack, 10, "9xx", 1),
+ kHaystack + 9);
+ EXPECT_TRUE(absl::strings_internal::memmem(kHaystack, 10, "9xx", 3) ==
+ nullptr);
+ EXPECT_TRUE(absl::strings_internal::memmem(kHaystack, 10, "xxx", 1) ==
+ nullptr);
+ }
+ {
+ const char kHaystack[] = "aBcDeFgHiJ";
+ EXPECT_EQ(absl::strings_internal::memcasemem(kHaystack, 0, "", 0),
+ kHaystack);
+ EXPECT_EQ(absl::strings_internal::memcasemem(kHaystack, 10, "Abc", 3),
+ kHaystack);
+ EXPECT_EQ(absl::strings_internal::memcasemem(kHaystack, 10, "Axx", 1),
+ kHaystack);
+ EXPECT_EQ(absl::strings_internal::memcasemem(kHaystack, 10, "hIj", 3),
+ kHaystack + 7);
+ EXPECT_EQ(absl::strings_internal::memcasemem(kHaystack, 10, "jxx", 1),
+ kHaystack + 9);
+ EXPECT_TRUE(absl::strings_internal::memcasemem(kHaystack, 10, "jxx", 3) ==
+ nullptr);
+ EXPECT_TRUE(absl::strings_internal::memcasemem(kHaystack, 10, "xxx", 1) ==
+ nullptr);
+ }
+ {
+ const char kHaystack[] = "0123456789";
+ EXPECT_EQ(absl::strings_internal::memmatch(kHaystack, 0, "", 0), kHaystack);
+ EXPECT_EQ(absl::strings_internal::memmatch(kHaystack, 10, "012", 3),
+ kHaystack);
+ EXPECT_EQ(absl::strings_internal::memmatch(kHaystack, 10, "0xx", 1),
+ kHaystack);
+ EXPECT_EQ(absl::strings_internal::memmatch(kHaystack, 10, "789", 3),
+ kHaystack + 7);
+ EXPECT_EQ(absl::strings_internal::memmatch(kHaystack, 10, "9xx", 1),
+ kHaystack + 9);
+ EXPECT_TRUE(absl::strings_internal::memmatch(kHaystack, 10, "9xx", 3) ==
+ nullptr);
+ EXPECT_TRUE(absl::strings_internal::memmatch(kHaystack, 10, "xxx", 1) ==
+ nullptr);
+ }
+}
+
+} // namespace
diff --git a/absl/strings/internal/numbers_test_common.h b/absl/strings/internal/numbers_test_common.h
new file mode 100644
index 0000000..2824720
--- /dev/null
+++ b/absl/strings/internal/numbers_test_common.h
@@ -0,0 +1,179 @@
+// Copyright 2017 The Abseil Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+// This file contains common things needed by numbers_test.cc,
+// numbers_legacy_test.cc and numbers_benchmark.cc.
+
+#ifndef ABSL_STRINGS_INTERNAL_NUMBERS_TEST_COMMON_H_
+#define ABSL_STRINGS_INTERNAL_NUMBERS_TEST_COMMON_H_
+
+#include <array>
+#include <cstdint>
+#include <limits>
+#include <string>
+
+namespace absl {
+namespace strings_internal {
+
+template <typename IntType>
+inline bool Itoa(IntType value, int base, std::string* destination) {
+ destination->clear();
+ if (base <= 1 || base > 36) {
+ return false;
+ }
+
+ if (value == 0) {
+ destination->push_back('0');
+ return true;
+ }
+
+ bool negative = value < 0;
+ while (value != 0) {
+ const IntType next_value = value / base;
+ // Can't use std::abs here because of problems when IntType is unsigned.
+ int remainder = value > next_value * base ? value - next_value * base
+ : next_value * base - value;
+ char c = remainder < 10 ? '0' + remainder : 'A' + remainder - 10;
+ destination->insert(0, 1, c);
+ value = next_value;
+ }
+
+ if (negative) {
+ destination->insert(0, 1, '-');
+ }
+ return true;
+}
+
+struct uint32_test_case {
+ const char* str;
+ bool expect_ok;
+ int base; // base to pass to the conversion function
+ uint32_t expected;
+};
+
+inline const std::array<uint32_test_case, 27>& strtouint32_test_cases() {
+ static const std::array<uint32_test_case, 27> test_cases{{
+ {"0xffffffff", true, 16, (std::numeric_limits<uint32_t>::max)()},
+ {"0x34234324", true, 16, 0x34234324},
+ {"34234324", true, 16, 0x34234324},
+ {"0", true, 16, 0},
+ {" \t\n 0xffffffff", true, 16, (std::numeric_limits<uint32_t>::max)()},
+ {" \f\v 46", true, 10, 46}, // must accept weird whitespace
+ {" \t\n 72717222", true, 8, 072717222},
+ {" \t\n 072717222", true, 8, 072717222},
+ {" \t\n 072717228", false, 8, 07271722},
+ {"0", true, 0, 0},
+
+ // Base-10 version.
+ {"34234324", true, 0, 34234324},
+ {"4294967295", true, 0, (std::numeric_limits<uint32_t>::max)()},
+ {"34234324 \n\t", true, 10, 34234324},
+
+ // Unusual base
+ {"0", true, 3, 0},
+ {"2", true, 3, 2},
+ {"11", true, 3, 4},
+
+ // Invalid uints.
+ {"", false, 0, 0},
+ {" ", false, 0, 0},
+ {"abc", false, 0, 0}, // would be valid hex, but prefix is missing
+ {"34234324a", false, 0, 34234324},
+ {"34234.3", false, 0, 34234},
+ {"-1", false, 0, 0},
+ {" -123", false, 0, 0},
+ {" \t\n -123", false, 0, 0},
+
+ // Out of bounds.
+ {"4294967296", false, 0, (std::numeric_limits<uint32_t>::max)()},
+ {"0x100000000", false, 0, (std::numeric_limits<uint32_t>::max)()},
+ {nullptr, false, 0, 0},
+ }};
+ return test_cases;
+}
+
+struct uint64_test_case {
+ const char* str;
+ bool expect_ok;
+ int base;
+ uint64_t expected;
+};
+
+inline const std::array<uint64_test_case, 34>& strtouint64_test_cases() {
+ static const std::array<uint64_test_case, 34> test_cases{{
+ {"0x3423432448783446", true, 16, int64_t{0x3423432448783446}},
+ {"3423432448783446", true, 16, int64_t{0x3423432448783446}},
+
+ {"0", true, 16, 0},
+ {"000", true, 0, 0},
+ {"0", true, 0, 0},
+ {" \t\n 0xffffffffffffffff", true, 16,
+ (std::numeric_limits<uint64_t>::max)()},
+
+ {"012345670123456701234", true, 8, int64_t{012345670123456701234}},
+ {"12345670123456701234", true, 8, int64_t{012345670123456701234}},
+
+ {"12845670123456701234", false, 8, 0},
+
+ // Base-10 version.
+ {"34234324487834466", true, 0, int64_t{34234324487834466}},
+
+ {" \t\n 18446744073709551615", true, 0,
+ (std::numeric_limits<uint64_t>::max)()},
+
+ {"34234324487834466 \n\t ", true, 0, int64_t{34234324487834466}},
+
+ {" \f\v 46", true, 10, 46}, // must accept weird whitespace
+
+ // Unusual base
+ {"0", true, 3, 0},
+ {"2", true, 3, 2},
+ {"11", true, 3, 4},
+
+ {"0", true, 0, 0},
+
+ // Invalid uints.
+ {"", false, 0, 0},
+ {" ", false, 0, 0},
+ {"abc", false, 0, 0},
+ {"34234324487834466a", false, 0, 0},
+ {"34234487834466.3", false, 0, 0},
+ {"-1", false, 0, 0},
+ {" -123", false, 0, 0},
+ {" \t\n -123", false, 0, 0},
+
+ // Out of bounds.
+ {"18446744073709551616", false, 10, 0},
+ {"18446744073709551616", false, 0, 0},
+ {"0x10000000000000000", false, 16,
+ (std::numeric_limits<uint64_t>::max)()},
+ {"0X10000000000000000", false, 16,
+ (std::numeric_limits<uint64_t>::max)()}, // 0X versus 0x.
+ {"0x10000000000000000", false, 0, (std::numeric_limits<uint64_t>::max)()},
+ {"0X10000000000000000", false, 0,
+ (std::numeric_limits<uint64_t>::max)()}, // 0X versus 0x.
+
+ {"0x1234", true, 16, 0x1234},
+
+ // Base-10 std::string version.
+ {"1234", true, 0, 1234},
+ {nullptr, false, 0, 0},
+ }};
+ return test_cases;
+}
+
+} // namespace strings_internal
+} // namespace absl
+
+#endif // ABSL_STRINGS_INTERNAL_NUMBERS_TEST_COMMON_H_
diff --git a/absl/strings/internal/ostringstream.cc b/absl/strings/internal/ostringstream.cc
new file mode 100644
index 0000000..d0f0f84
--- /dev/null
+++ b/absl/strings/internal/ostringstream.cc
@@ -0,0 +1,34 @@
+// Copyright 2017 The Abseil Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include "absl/strings/internal/ostringstream.h"
+
+namespace absl {
+namespace strings_internal {
+
+OStringStream::Buf::int_type OStringStream::overflow(int c) {
+ assert(s_);
+ if (!Buf::traits_type::eq_int_type(c, Buf::traits_type::eof()))
+ s_->push_back(static_cast<char>(c));
+ return 1;
+}
+
+std::streamsize OStringStream::xsputn(const char* s, std::streamsize n) {
+ assert(s_);
+ s_->append(s, n);
+ return n;
+}
+
+} // namespace strings_internal
+} // namespace absl
diff --git a/absl/strings/internal/ostringstream.h b/absl/strings/internal/ostringstream.h
new file mode 100644
index 0000000..2079201
--- /dev/null
+++ b/absl/strings/internal/ostringstream.h
@@ -0,0 +1,87 @@
+// Copyright 2017 The Abseil Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef ABSL_STRINGS_INTERNAL_OSTRINGSTREAM_H_
+#define ABSL_STRINGS_INTERNAL_OSTRINGSTREAM_H_
+
+#include <cassert>
+#include <ostream>
+#include <streambuf>
+#include <string>
+
+#include "absl/base/port.h"
+
+namespace absl {
+namespace strings_internal {
+
+// The same as std::ostringstream but appends to a user-specified std::string,
+// and is faster. It is ~70% faster to create, ~50% faster to write to, and
+// completely free to extract the result std::string.
+//
+// std::string s;
+// OStringStream strm(&s);
+// strm << 42 << ' ' << 3.14; // appends to `s`
+//
+// The stream object doesn't have to be named. Starting from C++11 operator<<
+// works with rvalues of std::ostream.
+//
+// std::string s;
+// OStringStream(&s) << 42 << ' ' << 3.14; // appends to `s`
+//
+// OStringStream is faster to create than std::ostringstream but it's still
+// relatively slow. Avoid creating multiple streams where a single stream will
+// do.
+//
+// Creates unnecessary instances of OStringStream: slow.
+//
+// std::string s;
+// OStringStream(&s) << 42;
+// OStringStream(&s) << ' ';
+// OStringStream(&s) << 3.14;
+//
+// Creates a single instance of OStringStream and reuses it: fast.
+//
+// std::string s;
+// OStringStream strm(&s);
+// strm << 42;
+// strm << ' ';
+// strm << 3.14;
+//
+// Note: flush() has no effect. No reason to call it.
+class OStringStream : private std::basic_streambuf<char>, public std::ostream {
+ public:
+ // The argument can be null, in which case you'll need to call str(p) with a
+ // non-null argument before you can write to the stream.
+ //
+ // The destructor of OStringStream doesn't use the std::string. It's OK to
+ // destroy the std::string before the stream.
+ explicit OStringStream(std::string* s) : std::ostream(this), s_(s) {}
+
+ std::string* str() { return s_; }
+ const std::string* str() const { return s_; }
+ void str(std::string* s) { s_ = s; }
+
+ private:
+ using Buf = std::basic_streambuf<char>;
+
+ Buf::int_type overflow(int c) override;
+ std::streamsize xsputn(const char* s, std::streamsize n) override;
+
+ std::string* s_;
+};
+
+} // namespace strings_internal
+} // namespace absl
+
+#endif // ABSL_STRINGS_INTERNAL_OSTRINGSTREAM_H_
diff --git a/absl/strings/internal/ostringstream_benchmark.cc b/absl/strings/internal/ostringstream_benchmark.cc
new file mode 100644
index 0000000..5979f18
--- /dev/null
+++ b/absl/strings/internal/ostringstream_benchmark.cc
@@ -0,0 +1,106 @@
+// Copyright 2018 The Abseil Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include "absl/strings/internal/ostringstream.h"
+
+#include <sstream>
+#include <string>
+
+#include "benchmark/benchmark.h"
+
+namespace {
+
+enum StringType {
+ kNone,
+ kStdString,
+};
+
+// Benchmarks for std::ostringstream.
+template <StringType kOutput>
+void BM_StdStream(benchmark::State& state) {
+ const int num_writes = state.range(0);
+ const int bytes_per_write = state.range(1);
+ const std::string payload(bytes_per_write, 'x');
+ for (auto _ : state) {
+ std::ostringstream strm;
+ benchmark::DoNotOptimize(strm);
+ for (int i = 0; i != num_writes; ++i) {
+ strm << payload;
+ }
+ switch (kOutput) {
+ case kNone: {
+ break;
+ }
+ case kStdString: {
+ std::string s = strm.str();
+ benchmark::DoNotOptimize(s);
+ break;
+ }
+ }
+ }
+}
+
+// Create the stream, optionally write to it, then destroy it.
+BENCHMARK_TEMPLATE(BM_StdStream, kNone)
+ ->ArgPair(0, 0)
+ ->ArgPair(1, 16) // 16 bytes is small enough for SSO
+ ->ArgPair(1, 256) // 256 bytes requires heap allocation
+ ->ArgPair(1024, 256);
+// Create the stream, write to it, get std::string out, then destroy.
+BENCHMARK_TEMPLATE(BM_StdStream, kStdString)
+ ->ArgPair(1, 16) // 16 bytes is small enough for SSO
+ ->ArgPair(1, 256) // 256 bytes requires heap allocation
+ ->ArgPair(1024, 256);
+
+// Benchmarks for OStringStream.
+template <StringType kOutput>
+void BM_CustomStream(benchmark::State& state) {
+ const int num_writes = state.range(0);
+ const int bytes_per_write = state.range(1);
+ const std::string payload(bytes_per_write, 'x');
+ for (auto _ : state) {
+ std::string out;
+ absl::strings_internal::OStringStream strm(&out);
+ benchmark::DoNotOptimize(strm);
+ for (int i = 0; i != num_writes; ++i) {
+ strm << payload;
+ }
+ switch (kOutput) {
+ case kNone: {
+ break;
+ }
+ case kStdString: {
+ std::string s = out;
+ benchmark::DoNotOptimize(s);
+ break;
+ }
+ }
+ }
+}
+
+// Create the stream, optionally write to it, then destroy it.
+BENCHMARK_TEMPLATE(BM_CustomStream, kNone)
+ ->ArgPair(0, 0)
+ ->ArgPair(1, 16) // 16 bytes is small enough for SSO
+ ->ArgPair(1, 256) // 256 bytes requires heap allocation
+ ->ArgPair(1024, 256);
+// Create the stream, write to it, get std::string out, then destroy.
+// It's not useful in practice to extract std::string from OStringStream; we
+// measure it for completeness.
+BENCHMARK_TEMPLATE(BM_CustomStream, kStdString)
+ ->ArgPair(1, 16) // 16 bytes is small enough for SSO
+ ->ArgPair(1, 256) // 256 bytes requires heap allocation
+ ->ArgPair(1024, 256);
+
+} // namespace
diff --git a/absl/strings/internal/ostringstream_test.cc b/absl/strings/internal/ostringstream_test.cc
new file mode 100644
index 0000000..2879e50
--- /dev/null
+++ b/absl/strings/internal/ostringstream_test.cc
@@ -0,0 +1,102 @@
+// Copyright 2017 The Abseil Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include "absl/strings/internal/ostringstream.h"
+
+#include <memory>
+#include <ostream>
+#include <string>
+#include <type_traits>
+
+#include "gtest/gtest.h"
+
+namespace {
+
+TEST(OStringStream, IsOStream) {
+ static_assert(
+ std::is_base_of<std::ostream, absl::strings_internal::OStringStream>(),
+ "");
+}
+
+TEST(OStringStream, ConstructDestroy) {
+ {
+ absl::strings_internal::OStringStream strm(nullptr);
+ EXPECT_EQ(nullptr, strm.str());
+ }
+ {
+ std::string s = "abc";
+ {
+ absl::strings_internal::OStringStream strm(&s);
+ EXPECT_EQ(&s, strm.str());
+ }
+ EXPECT_EQ("abc", s);
+ }
+ {
+ std::unique_ptr<std::string> s(new std::string);
+ absl::strings_internal::OStringStream strm(s.get());
+ s.reset();
+ }
+}
+
+TEST(OStringStream, Str) {
+ std::string s1;
+ absl::strings_internal::OStringStream strm(&s1);
+ const absl::strings_internal::OStringStream& c_strm(strm);
+
+ static_assert(std::is_same<decltype(strm.str()), std::string*>(), "");
+ static_assert(std::is_same<decltype(c_strm.str()), const std::string*>(), "");
+
+ EXPECT_EQ(&s1, strm.str());
+ EXPECT_EQ(&s1, c_strm.str());
+
+ strm.str(&s1);
+ EXPECT_EQ(&s1, strm.str());
+ EXPECT_EQ(&s1, c_strm.str());
+
+ std::string s2;
+ strm.str(&s2);
+ EXPECT_EQ(&s2, strm.str());
+ EXPECT_EQ(&s2, c_strm.str());
+
+ strm.str(nullptr);
+ EXPECT_EQ(nullptr, strm.str());
+ EXPECT_EQ(nullptr, c_strm.str());
+}
+
+TEST(OStreamStream, WriteToLValue) {
+ std::string s = "abc";
+ {
+ absl::strings_internal::OStringStream strm(&s);
+ EXPECT_EQ("abc", s);
+ strm << "";
+ EXPECT_EQ("abc", s);
+ strm << 42;
+ EXPECT_EQ("abc42", s);
+ strm << 'x' << 'y';
+ EXPECT_EQ("abc42xy", s);
+ }
+ EXPECT_EQ("abc42xy", s);
+}
+
+TEST(OStreamStream, WriteToRValue) {
+ std::string s = "abc";
+ absl::strings_internal::OStringStream(&s) << "";
+ EXPECT_EQ("abc", s);
+ absl::strings_internal::OStringStream(&s) << 42;
+ EXPECT_EQ("abc42", s);
+ absl::strings_internal::OStringStream(&s) << 'x' << 'y';
+ EXPECT_EQ("abc42xy", s);
+}
+
+} // namespace
diff --git a/absl/strings/internal/pow10_helper.cc b/absl/strings/internal/pow10_helper.cc
new file mode 100644
index 0000000..03ed8d0
--- /dev/null
+++ b/absl/strings/internal/pow10_helper.cc
@@ -0,0 +1,120 @@
+// Copyright 2018 The Abseil Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include "absl/strings/internal/pow10_helper.h"
+
+#include <cmath>
+
+namespace absl {
+namespace strings_internal {
+
+namespace {
+
+// The exact value of 1e23 falls precisely halfway between two representable
+// doubles. Furthermore, the rounding rules we prefer (break ties by rounding
+// to the nearest even) dictate in this case that the number should be rounded
+// down, but this is not completely specified for floating-point literals in
+// C++. (It just says to use the default rounding mode of the standard
+// library.) We ensure the result we want by using a number that has an
+// unambiguous correctly rounded answer.
+constexpr double k1e23 = 9999999999999999e7;
+
+constexpr double kPowersOfTen[] = {
+ 0.0, 1e-323, 1e-322, 1e-321, 1e-320, 1e-319, 1e-318, 1e-317, 1e-316,
+ 1e-315, 1e-314, 1e-313, 1e-312, 1e-311, 1e-310, 1e-309, 1e-308, 1e-307,
+ 1e-306, 1e-305, 1e-304, 1e-303, 1e-302, 1e-301, 1e-300, 1e-299, 1e-298,
+ 1e-297, 1e-296, 1e-295, 1e-294, 1e-293, 1e-292, 1e-291, 1e-290, 1e-289,
+ 1e-288, 1e-287, 1e-286, 1e-285, 1e-284, 1e-283, 1e-282, 1e-281, 1e-280,
+ 1e-279, 1e-278, 1e-277, 1e-276, 1e-275, 1e-274, 1e-273, 1e-272, 1e-271,
+ 1e-270, 1e-269, 1e-268, 1e-267, 1e-266, 1e-265, 1e-264, 1e-263, 1e-262,
+ 1e-261, 1e-260, 1e-259, 1e-258, 1e-257, 1e-256, 1e-255, 1e-254, 1e-253,
+ 1e-252, 1e-251, 1e-250, 1e-249, 1e-248, 1e-247, 1e-246, 1e-245, 1e-244,
+ 1e-243, 1e-242, 1e-241, 1e-240, 1e-239, 1e-238, 1e-237, 1e-236, 1e-235,
+ 1e-234, 1e-233, 1e-232, 1e-231, 1e-230, 1e-229, 1e-228, 1e-227, 1e-226,
+ 1e-225, 1e-224, 1e-223, 1e-222, 1e-221, 1e-220, 1e-219, 1e-218, 1e-217,
+ 1e-216, 1e-215, 1e-214, 1e-213, 1e-212, 1e-211, 1e-210, 1e-209, 1e-208,
+ 1e-207, 1e-206, 1e-205, 1e-204, 1e-203, 1e-202, 1e-201, 1e-200, 1e-199,
+ 1e-198, 1e-197, 1e-196, 1e-195, 1e-194, 1e-193, 1e-192, 1e-191, 1e-190,
+ 1e-189, 1e-188, 1e-187, 1e-186, 1e-185, 1e-184, 1e-183, 1e-182, 1e-181,
+ 1e-180, 1e-179, 1e-178, 1e-177, 1e-176, 1e-175, 1e-174, 1e-173, 1e-172,
+ 1e-171, 1e-170, 1e-169, 1e-168, 1e-167, 1e-166, 1e-165, 1e-164, 1e-163,
+ 1e-162, 1e-161, 1e-160, 1e-159, 1e-158, 1e-157, 1e-156, 1e-155, 1e-154,
+ 1e-153, 1e-152, 1e-151, 1e-150, 1e-149, 1e-148, 1e-147, 1e-146, 1e-145,
+ 1e-144, 1e-143, 1e-142, 1e-141, 1e-140, 1e-139, 1e-138, 1e-137, 1e-136,
+ 1e-135, 1e-134, 1e-133, 1e-132, 1e-131, 1e-130, 1e-129, 1e-128, 1e-127,
+ 1e-126, 1e-125, 1e-124, 1e-123, 1e-122, 1e-121, 1e-120, 1e-119, 1e-118,
+ 1e-117, 1e-116, 1e-115, 1e-114, 1e-113, 1e-112, 1e-111, 1e-110, 1e-109,
+ 1e-108, 1e-107, 1e-106, 1e-105, 1e-104, 1e-103, 1e-102, 1e-101, 1e-100,
+ 1e-99, 1e-98, 1e-97, 1e-96, 1e-95, 1e-94, 1e-93, 1e-92, 1e-91,
+ 1e-90, 1e-89, 1e-88, 1e-87, 1e-86, 1e-85, 1e-84, 1e-83, 1e-82,
+ 1e-81, 1e-80, 1e-79, 1e-78, 1e-77, 1e-76, 1e-75, 1e-74, 1e-73,
+ 1e-72, 1e-71, 1e-70, 1e-69, 1e-68, 1e-67, 1e-66, 1e-65, 1e-64,
+ 1e-63, 1e-62, 1e-61, 1e-60, 1e-59, 1e-58, 1e-57, 1e-56, 1e-55,
+ 1e-54, 1e-53, 1e-52, 1e-51, 1e-50, 1e-49, 1e-48, 1e-47, 1e-46,
+ 1e-45, 1e-44, 1e-43, 1e-42, 1e-41, 1e-40, 1e-39, 1e-38, 1e-37,
+ 1e-36, 1e-35, 1e-34, 1e-33, 1e-32, 1e-31, 1e-30, 1e-29, 1e-28,
+ 1e-27, 1e-26, 1e-25, 1e-24, 1e-23, 1e-22, 1e-21, 1e-20, 1e-19,
+ 1e-18, 1e-17, 1e-16, 1e-15, 1e-14, 1e-13, 1e-12, 1e-11, 1e-10,
+ 1e-9, 1e-8, 1e-7, 1e-6, 1e-5, 1e-4, 1e-3, 1e-2, 1e-1,
+ 1e+0, 1e+1, 1e+2, 1e+3, 1e+4, 1e+5, 1e+6, 1e+7, 1e+8,
+ 1e+9, 1e+10, 1e+11, 1e+12, 1e+13, 1e+14, 1e+15, 1e+16, 1e+17,
+ 1e+18, 1e+19, 1e+20, 1e+21, 1e+22, k1e23, 1e+24, 1e+25, 1e+26,
+ 1e+27, 1e+28, 1e+29, 1e+30, 1e+31, 1e+32, 1e+33, 1e+34, 1e+35,
+ 1e+36, 1e+37, 1e+38, 1e+39, 1e+40, 1e+41, 1e+42, 1e+43, 1e+44,
+ 1e+45, 1e+46, 1e+47, 1e+48, 1e+49, 1e+50, 1e+51, 1e+52, 1e+53,
+ 1e+54, 1e+55, 1e+56, 1e+57, 1e+58, 1e+59, 1e+60, 1e+61, 1e+62,
+ 1e+63, 1e+64, 1e+65, 1e+66, 1e+67, 1e+68, 1e+69, 1e+70, 1e+71,
+ 1e+72, 1e+73, 1e+74, 1e+75, 1e+76, 1e+77, 1e+78, 1e+79, 1e+80,
+ 1e+81, 1e+82, 1e+83, 1e+84, 1e+85, 1e+86, 1e+87, 1e+88, 1e+89,
+ 1e+90, 1e+91, 1e+92, 1e+93, 1e+94, 1e+95, 1e+96, 1e+97, 1e+98,
+ 1e+99, 1e+100, 1e+101, 1e+102, 1e+103, 1e+104, 1e+105, 1e+106, 1e+107,
+ 1e+108, 1e+109, 1e+110, 1e+111, 1e+112, 1e+113, 1e+114, 1e+115, 1e+116,
+ 1e+117, 1e+118, 1e+119, 1e+120, 1e+121, 1e+122, 1e+123, 1e+124, 1e+125,
+ 1e+126, 1e+127, 1e+128, 1e+129, 1e+130, 1e+131, 1e+132, 1e+133, 1e+134,
+ 1e+135, 1e+136, 1e+137, 1e+138, 1e+139, 1e+140, 1e+141, 1e+142, 1e+143,
+ 1e+144, 1e+145, 1e+146, 1e+147, 1e+148, 1e+149, 1e+150, 1e+151, 1e+152,
+ 1e+153, 1e+154, 1e+155, 1e+156, 1e+157, 1e+158, 1e+159, 1e+160, 1e+161,
+ 1e+162, 1e+163, 1e+164, 1e+165, 1e+166, 1e+167, 1e+168, 1e+169, 1e+170,
+ 1e+171, 1e+172, 1e+173, 1e+174, 1e+175, 1e+176, 1e+177, 1e+178, 1e+179,
+ 1e+180, 1e+181, 1e+182, 1e+183, 1e+184, 1e+185, 1e+186, 1e+187, 1e+188,
+ 1e+189, 1e+190, 1e+191, 1e+192, 1e+193, 1e+194, 1e+195, 1e+196, 1e+197,
+ 1e+198, 1e+199, 1e+200, 1e+201, 1e+202, 1e+203, 1e+204, 1e+205, 1e+206,
+ 1e+207, 1e+208, 1e+209, 1e+210, 1e+211, 1e+212, 1e+213, 1e+214, 1e+215,
+ 1e+216, 1e+217, 1e+218, 1e+219, 1e+220, 1e+221, 1e+222, 1e+223, 1e+224,
+ 1e+225, 1e+226, 1e+227, 1e+228, 1e+229, 1e+230, 1e+231, 1e+232, 1e+233,
+ 1e+234, 1e+235, 1e+236, 1e+237, 1e+238, 1e+239, 1e+240, 1e+241, 1e+242,
+ 1e+243, 1e+244, 1e+245, 1e+246, 1e+247, 1e+248, 1e+249, 1e+250, 1e+251,
+ 1e+252, 1e+253, 1e+254, 1e+255, 1e+256, 1e+257, 1e+258, 1e+259, 1e+260,
+ 1e+261, 1e+262, 1e+263, 1e+264, 1e+265, 1e+266, 1e+267, 1e+268, 1e+269,
+ 1e+270, 1e+271, 1e+272, 1e+273, 1e+274, 1e+275, 1e+276, 1e+277, 1e+278,
+ 1e+279, 1e+280, 1e+281, 1e+282, 1e+283, 1e+284, 1e+285, 1e+286, 1e+287,
+ 1e+288, 1e+289, 1e+290, 1e+291, 1e+292, 1e+293, 1e+294, 1e+295, 1e+296,
+ 1e+297, 1e+298, 1e+299, 1e+300, 1e+301, 1e+302, 1e+303, 1e+304, 1e+305,
+ 1e+306, 1e+307, 1e+308,
+};
+
+} // namespace
+
+double Pow10(int exp) {
+ if (exp < -324) {
+ return 0.0;
+ } else if (exp > 308) {
+ return INFINITY;
+ } else {
+ return kPowersOfTen[exp + 324];
+ }
+}
+
+} // namespace strings_internal
+} // namespace absl
diff --git a/absl/strings/internal/pow10_helper.h b/absl/strings/internal/pow10_helper.h
new file mode 100644
index 0000000..9d1aa71
--- /dev/null
+++ b/absl/strings/internal/pow10_helper.h
@@ -0,0 +1,36 @@
+//
+// Copyright 2018 The Abseil Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+// This test helper library contains a table of powers of 10, to guarantee
+// precise values are computed across the full range of doubles. We can't rely
+// on the pow() function, because not all standard libraries ship a version
+// that is precise.
+#ifndef ABSL_STRINGS_INTERNAL_POW10_HELPER_H_
+#define ABSL_STRINGS_INTERNAL_POW10_HELPER_H_
+
+#include <vector>
+
+namespace absl {
+namespace strings_internal {
+
+// Computes the precise value of 10^exp. (I.e. the nearest representable
+// double to the exact value, rounding to nearest-even in the (single) case of
+// being exactly halfway between.)
+double Pow10(int exp);
+
+} // namespace strings_internal
+} // namespace absl
+
+#endif // ABSL_STRINGS_INTERNAL_POW10_HELPER_H_
diff --git a/absl/strings/internal/pow10_helper_test.cc b/absl/strings/internal/pow10_helper_test.cc
new file mode 100644
index 0000000..a4a68b5
--- /dev/null
+++ b/absl/strings/internal/pow10_helper_test.cc
@@ -0,0 +1,120 @@
+// Copyright 2018 The Abseil Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include "absl/strings/internal/pow10_helper.h"
+
+#include <cmath>
+
+#include "gtest/gtest.h"
+#include "absl/strings/str_format.h"
+
+namespace absl {
+namespace strings_internal {
+
+namespace {
+
+struct TestCase {
+ int power; // Testing Pow10(power)
+ uint64_t significand; // Raw bits of the expected value
+ int radix; // significand is adjusted by 2^radix
+};
+
+TEST(Pow10HelperTest, Works) {
+ // The logic in pow10_helper.cc is so simple that theoretically we don't even
+ // need a test. However, we're paranoid and believe that there may be
+ // compilers that don't round floating-point literals correctly, even though
+ // it is specified by the standard. We check various edge cases, just to be
+ // sure.
+ constexpr TestCase kTestCases[] = {
+ // Subnormals
+ {-323, 0x2, -1074},
+ {-322, 0x14, -1074},
+ {-321, 0xca, -1074},
+ {-320, 0x7e8, -1074},
+ {-319, 0x4f10, -1074},
+ {-318, 0x316a2, -1074},
+ {-317, 0x1ee257, -1074},
+ {-316, 0x134d761, -1074},
+ {-315, 0xc1069cd, -1074},
+ {-314, 0x78a42205, -1074},
+ {-313, 0x4b6695433, -1074},
+ {-312, 0x2f201d49fb, -1074},
+ {-311, 0x1d74124e3d1, -1074},
+ {-310, 0x12688b70e62b, -1074},
+ {-309, 0xb8157268fdaf, -1074},
+ {-308, 0x730d67819e8d2, -1074},
+ // Values that are very close to rounding the other way.
+ // Comment shows difference of significand from the true value.
+ {-307, 0x11fa182c40c60d, -1072}, // -.4588
+ {-290, 0x18f2b061aea072, -1016}, // .4854
+ {-276, 0x11BA03F5B21000, -969}, // .4709
+ {-259, 0x1899C2F6732210, -913}, // .4830
+ {-252, 0x1D53844EE47DD1, -890}, // -.4743
+ {-227, 0x1E5297287C2F45, -807}, // -.4708
+ {-198, 0x1322E220A5B17E, -710}, // -.4714
+ {-195, 0x12B010D3E1CF56, -700}, // .4928
+ {-192, 0x123FF06EEA847A, -690}, // .4968
+ {-163, 0x1708D0F84D3DE7, -594}, // -.4977
+ {-145, 0x13FAAC3E3FA1F3, -534}, // -.4785
+ {-111, 0x133D4032C2C7F5, -421}, // .4774
+ {-106, 0x1D5B561574765B, -405}, // -.4869
+ {-104, 0x16EF5B40C2FC77, -398}, // -.4741
+ {-88, 0x197683DF2F268D, -345}, // -.4738
+ {-86, 0x13E497065CD61F, -338}, // .4736
+ {-76, 0x17288E1271F513, -305}, // -.4761
+ {-63, 0x1A53FC9631D10D, -262}, // .4929
+ {-30, 0x14484BFEEBC2A0, -152}, // .4758
+ {-21, 0x12E3B40A0E9B4F, -122}, // -.4916
+ {-5, 0x14F8B588E368F1, -69}, // .4829
+ {23, 0x152D02C7E14AF6, 24}, // -.5000 (exactly, round-to-even)
+ {29, 0x1431E0FAE6D721, 44}, // -.4870
+ {34, 0x1ED09BEAD87C03, 60}, // -.4721
+ {70, 0x172EBAD6DDC73D, 180}, // .4733
+ {105, 0x1BE7ABD3781ECA, 296}, // -.4850
+ {126, 0x17A2ECC414A03F, 366}, // -.4999
+ {130, 0x1CDA62055B2D9E, 379}, // .4855
+ {165, 0x115D847AD00087, 496}, // -.4913
+ {172, 0x14B378469B6732, 519}, // .4818
+ {187, 0x1262DFEEBBB0F9, 569}, // -.4805
+ {210, 0x18557F31326BBB, 645}, // -.4992
+ {212, 0x1302CB5E6F642A, 652}, // -.4838
+ {215, 0x1290BA9A38C7D1, 662}, // -.4881
+ {236, 0x1F736F9B3494E9, 731}, // .4707
+ {244, 0x176EC98994F489, 758}, // .4924
+ {250, 0x1658E3AB795204, 778}, // -.4963
+ {252, 0x117571DDF6C814, 785}, // .4873
+ {254, 0x1B4781EAD1989E, 791}, // -.4887
+ {260, 0x1A03FDE214CAF1, 811}, // .4784
+ {284, 0x1585041B2C477F, 891}, // .4798
+ {304, 0x1D2A1BE4048F90, 957}, // -.4987
+ // Out-of-range values
+ {-324, 0x0, 0},
+ {-325, 0x0, 0},
+ {-326, 0x0, 0},
+ {309, 1, 2000},
+ {310, 1, 2000},
+ {311, 1, 2000},
+ };
+ for (const TestCase& test_case : kTestCases) {
+ EXPECT_EQ(Pow10(test_case.power),
+ std::ldexp(test_case.significand, test_case.radix))
+ << absl::StrFormat("Failure for Pow10(%d): %a vs %a", test_case.power,
+ Pow10(test_case.power),
+ std::ldexp(test_case.significand, test_case.radix));
+ }
+}
+
+} // namespace
+} // namespace strings_internal
+} // namespace absl
diff --git a/absl/strings/internal/resize_uninitialized.h b/absl/strings/internal/resize_uninitialized.h
new file mode 100644
index 0000000..469962b
--- /dev/null
+++ b/absl/strings/internal/resize_uninitialized.h
@@ -0,0 +1,72 @@
+//
+// Copyright 2017 The Abseil Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+
+#ifndef ABSL_STRINGS_INTERNAL_RESIZE_UNINITIALIZED_H_
+#define ABSL_STRINGS_INTERNAL_RESIZE_UNINITIALIZED_H_
+
+#include <string>
+#include <type_traits>
+#include <utility>
+
+#include "absl/base/port.h"
+#include "absl/meta/type_traits.h" // for void_t
+
+namespace absl {
+namespace strings_internal {
+
+// Is a subclass of true_type or false_type, depending on whether or not
+// T has a __resize_default_init member.
+template <typename string_type, typename = void>
+struct ResizeUninitializedTraits {
+ using HasMember = std::false_type;
+ static void Resize(string_type* s, size_t new_size) { s->resize(new_size); }
+};
+
+// __resize_default_init is provided by libc++ >= 8.0 and by Google's internal
+// ::string implementation.
+template <typename string_type>
+struct ResizeUninitializedTraits<
+ string_type, absl::void_t<decltype(std::declval<string_type&>()
+ .__resize_default_init(237))> > {
+ using HasMember = std::true_type;
+ static void Resize(string_type* s, size_t new_size) {
+ s->__resize_default_init(new_size);
+ }
+};
+
+// Returns true if the std::string implementation supports a resize where
+// the new characters added to the std::string are left untouched.
+//
+// (A better name might be "STLStringSupportsUninitializedResize", alluding to
+// the previous function.)
+template <typename string_type>
+inline constexpr bool STLStringSupportsNontrashingResize(string_type*) {
+ return ResizeUninitializedTraits<string_type>::HasMember::value;
+}
+
+// Like str->resize(new_size), except any new characters added to "*str" as a
+// result of resizing may be left uninitialized, rather than being filled with
+// '0' bytes. Typically used when code is then going to overwrite the backing
+// store of the std::string with known data.
+template <typename string_type, typename = void>
+inline void STLStringResizeUninitialized(string_type* s, size_t new_size) {
+ ResizeUninitializedTraits<string_type>::Resize(s, new_size);
+}
+
+} // namespace strings_internal
+} // namespace absl
+
+#endif // ABSL_STRINGS_INTERNAL_RESIZE_UNINITIALIZED_H_
diff --git a/absl/strings/internal/resize_uninitialized_test.cc b/absl/strings/internal/resize_uninitialized_test.cc
new file mode 100644
index 0000000..c5be0b1
--- /dev/null
+++ b/absl/strings/internal/resize_uninitialized_test.cc
@@ -0,0 +1,68 @@
+// Copyright 2017 The Abseil Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include "absl/strings/internal/resize_uninitialized.h"
+
+#include "gtest/gtest.h"
+
+namespace {
+
+int resize_call_count = 0;
+
+struct resizable_string {
+ void resize(size_t) { resize_call_count += 1; }
+};
+
+int resize_default_init_call_count = 0;
+
+struct resize_default_init_string {
+ void resize(size_t) { resize_call_count += 1; }
+ void __resize_default_init(size_t) { resize_default_init_call_count += 1; }
+};
+
+TEST(ResizeUninit, WithAndWithout) {
+ resize_call_count = 0;
+ resize_default_init_call_count = 0;
+ {
+ resizable_string rs;
+
+ EXPECT_EQ(resize_call_count, 0);
+ EXPECT_EQ(resize_default_init_call_count, 0);
+ EXPECT_FALSE(
+ absl::strings_internal::STLStringSupportsNontrashingResize(&rs));
+ EXPECT_EQ(resize_call_count, 0);
+ EXPECT_EQ(resize_default_init_call_count, 0);
+ absl::strings_internal::STLStringResizeUninitialized(&rs, 237);
+ EXPECT_EQ(resize_call_count, 1);
+ EXPECT_EQ(resize_default_init_call_count, 0);
+ }
+
+ resize_call_count = 0;
+ resize_default_init_call_count = 0;
+ {
+ resize_default_init_string rus;
+
+ EXPECT_EQ(resize_call_count, 0);
+ EXPECT_EQ(resize_default_init_call_count, 0);
+ EXPECT_TRUE(
+ absl::strings_internal::STLStringSupportsNontrashingResize(&rus));
+ EXPECT_EQ(resize_call_count, 0);
+ EXPECT_EQ(resize_default_init_call_count, 0);
+ absl::strings_internal::STLStringResizeUninitialized(&rus, 237);
+ EXPECT_EQ(resize_call_count, 0);
+ EXPECT_EQ(resize_default_init_call_count, 1);
+ }
+}
+
+} // namespace
diff --git a/absl/strings/internal/stl_type_traits.h b/absl/strings/internal/stl_type_traits.h
new file mode 100644
index 0000000..202ab37
--- /dev/null
+++ b/absl/strings/internal/stl_type_traits.h
@@ -0,0 +1,246 @@
+// Copyright 2017 The Abseil Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+
+// Thie file provides the IsStrictlyBaseOfAndConvertibleToSTLContainer type
+// trait metafunction to assist in working with the _GLIBCXX_DEBUG debug
+// wrappers of STL containers.
+//
+// DO NOT INCLUDE THIS FILE DIRECTLY. Use this file by including
+// absl/strings/str_split.h.
+//
+// IWYU pragma: private, include "absl/strings/str_split.h"
+
+#ifndef ABSL_STRINGS_INTERNAL_STL_TYPE_TRAITS_H_
+#define ABSL_STRINGS_INTERNAL_STL_TYPE_TRAITS_H_
+
+#include <array>
+#include <bitset>
+#include <deque>
+#include <forward_list>
+#include <list>
+#include <map>
+#include <set>
+#include <type_traits>
+#include <unordered_map>
+#include <unordered_set>
+#include <vector>
+
+#include "absl/meta/type_traits.h"
+
+namespace absl {
+namespace strings_internal {
+
+template <typename C, template <typename...> class T>
+struct IsSpecializationImpl : std::false_type {};
+template <template <typename...> class T, typename... Args>
+struct IsSpecializationImpl<T<Args...>, T> : std::true_type {};
+template <typename C, template <typename...> class T>
+using IsSpecialization = IsSpecializationImpl<absl::decay_t<C>, T>;
+
+template <typename C>
+struct IsArrayImpl : std::false_type {};
+template <template <typename, size_t> class A, typename T, size_t N>
+struct IsArrayImpl<A<T, N>> : std::is_same<A<T, N>, std::array<T, N>> {};
+template <typename C>
+using IsArray = IsArrayImpl<absl::decay_t<C>>;
+
+template <typename C>
+struct IsBitsetImpl : std::false_type {};
+template <template <size_t> class B, size_t N>
+struct IsBitsetImpl<B<N>> : std::is_same<B<N>, std::bitset<N>> {};
+template <typename C>
+using IsBitset = IsBitsetImpl<absl::decay_t<C>>;
+
+template <typename C>
+struct IsSTLContainer
+ : absl::disjunction<
+ IsArray<C>, IsBitset<C>, IsSpecialization<C, std::deque>,
+ IsSpecialization<C, std::forward_list>,
+ IsSpecialization<C, std::list>, IsSpecialization<C, std::map>,
+ IsSpecialization<C, std::multimap>, IsSpecialization<C, std::set>,
+ IsSpecialization<C, std::multiset>,
+ IsSpecialization<C, std::unordered_map>,
+ IsSpecialization<C, std::unordered_multimap>,
+ IsSpecialization<C, std::unordered_set>,
+ IsSpecialization<C, std::unordered_multiset>,
+ IsSpecialization<C, std::vector>> {};
+
+template <typename C, template <typename...> class T, typename = void>
+struct IsBaseOfSpecializationImpl : std::false_type {};
+// IsBaseOfSpecializationImpl needs multiple partial specializations to SFINAE
+// on the existence of container dependent types and plug them into the STL
+// template.
+template <typename C, template <typename, typename> class T>
+struct IsBaseOfSpecializationImpl<
+ C, T, absl::void_t<typename C::value_type, typename C::allocator_type>>
+ : std::is_base_of<C,
+ T<typename C::value_type, typename C::allocator_type>> {};
+template <typename C, template <typename, typename, typename> class T>
+struct IsBaseOfSpecializationImpl<
+ C, T,
+ absl::void_t<typename C::key_type, typename C::key_compare,
+ typename C::allocator_type>>
+ : std::is_base_of<C, T<typename C::key_type, typename C::key_compare,
+ typename C::allocator_type>> {};
+template <typename C, template <typename, typename, typename, typename> class T>
+struct IsBaseOfSpecializationImpl<
+ C, T,
+ absl::void_t<typename C::key_type, typename C::mapped_type,
+ typename C::key_compare, typename C::allocator_type>>
+ : std::is_base_of<C,
+ T<typename C::key_type, typename C::mapped_type,
+ typename C::key_compare, typename C::allocator_type>> {
+};
+template <typename C, template <typename, typename, typename, typename> class T>
+struct IsBaseOfSpecializationImpl<
+ C, T,
+ absl::void_t<typename C::key_type, typename C::hasher,
+ typename C::key_equal, typename C::allocator_type>>
+ : std::is_base_of<C, T<typename C::key_type, typename C::hasher,
+ typename C::key_equal, typename C::allocator_type>> {
+};
+template <typename C,
+ template <typename, typename, typename, typename, typename> class T>
+struct IsBaseOfSpecializationImpl<
+ C, T,
+ absl::void_t<typename C::key_type, typename C::mapped_type,
+ typename C::hasher, typename C::key_equal,
+ typename C::allocator_type>>
+ : std::is_base_of<C, T<typename C::key_type, typename C::mapped_type,
+ typename C::hasher, typename C::key_equal,
+ typename C::allocator_type>> {};
+template <typename C, template <typename...> class T>
+using IsBaseOfSpecialization = IsBaseOfSpecializationImpl<absl::decay_t<C>, T>;
+
+template <typename C>
+struct IsBaseOfArrayImpl : std::false_type {};
+template <template <typename, size_t> class A, typename T, size_t N>
+struct IsBaseOfArrayImpl<A<T, N>> : std::is_base_of<A<T, N>, std::array<T, N>> {
+};
+template <typename C>
+using IsBaseOfArray = IsBaseOfArrayImpl<absl::decay_t<C>>;
+
+template <typename C>
+struct IsBaseOfBitsetImpl : std::false_type {};
+template <template <size_t> class B, size_t N>
+struct IsBaseOfBitsetImpl<B<N>> : std::is_base_of<B<N>, std::bitset<N>> {};
+template <typename C>
+using IsBaseOfBitset = IsBaseOfBitsetImpl<absl::decay_t<C>>;
+
+template <typename C>
+struct IsBaseOfSTLContainer
+ : absl::disjunction<IsBaseOfArray<C>, IsBaseOfBitset<C>,
+ IsBaseOfSpecialization<C, std::deque>,
+ IsBaseOfSpecialization<C, std::forward_list>,
+ IsBaseOfSpecialization<C, std::list>,
+ IsBaseOfSpecialization<C, std::map>,
+ IsBaseOfSpecialization<C, std::multimap>,
+ IsBaseOfSpecialization<C, std::set>,
+ IsBaseOfSpecialization<C, std::multiset>,
+ IsBaseOfSpecialization<C, std::unordered_map>,
+ IsBaseOfSpecialization<C, std::unordered_multimap>,
+ IsBaseOfSpecialization<C, std::unordered_set>,
+ IsBaseOfSpecialization<C, std::unordered_multiset>,
+ IsBaseOfSpecialization<C, std::vector>> {};
+
+template <typename C, template <typename...> class T, typename = void>
+struct IsConvertibleToSpecializationImpl : std::false_type {};
+// IsConvertibleToSpecializationImpl needs multiple partial specializations to
+// SFINAE on the existence of container dependent types and plug them into the
+// STL template.
+template <typename C, template <typename, typename> class T>
+struct IsConvertibleToSpecializationImpl<
+ C, T, absl::void_t<typename C::value_type, typename C::allocator_type>>
+ : std::is_convertible<
+ C, T<typename C::value_type, typename C::allocator_type>> {};
+template <typename C, template <typename, typename, typename> class T>
+struct IsConvertibleToSpecializationImpl<
+ C, T,
+ absl::void_t<typename C::key_type, typename C::key_compare,
+ typename C::allocator_type>>
+ : std::is_convertible<C, T<typename C::key_type, typename C::key_compare,
+ typename C::allocator_type>> {};
+template <typename C, template <typename, typename, typename, typename> class T>
+struct IsConvertibleToSpecializationImpl<
+ C, T,
+ absl::void_t<typename C::key_type, typename C::mapped_type,
+ typename C::key_compare, typename C::allocator_type>>
+ : std::is_convertible<
+ C, T<typename C::key_type, typename C::mapped_type,
+ typename C::key_compare, typename C::allocator_type>> {};
+template <typename C, template <typename, typename, typename, typename> class T>
+struct IsConvertibleToSpecializationImpl<
+ C, T,
+ absl::void_t<typename C::key_type, typename C::hasher,
+ typename C::key_equal, typename C::allocator_type>>
+ : std::is_convertible<
+ C, T<typename C::key_type, typename C::hasher, typename C::key_equal,
+ typename C::allocator_type>> {};
+template <typename C,
+ template <typename, typename, typename, typename, typename> class T>
+struct IsConvertibleToSpecializationImpl<
+ C, T,
+ absl::void_t<typename C::key_type, typename C::mapped_type,
+ typename C::hasher, typename C::key_equal,
+ typename C::allocator_type>>
+ : std::is_convertible<C, T<typename C::key_type, typename C::mapped_type,
+ typename C::hasher, typename C::key_equal,
+ typename C::allocator_type>> {};
+template <typename C, template <typename...> class T>
+using IsConvertibleToSpecialization =
+ IsConvertibleToSpecializationImpl<absl::decay_t<C>, T>;
+
+template <typename C>
+struct IsConvertibleToArrayImpl : std::false_type {};
+template <template <typename, size_t> class A, typename T, size_t N>
+struct IsConvertibleToArrayImpl<A<T, N>>
+ : std::is_convertible<A<T, N>, std::array<T, N>> {};
+template <typename C>
+using IsConvertibleToArray = IsConvertibleToArrayImpl<absl::decay_t<C>>;
+
+template <typename C>
+struct IsConvertibleToBitsetImpl : std::false_type {};
+template <template <size_t> class B, size_t N>
+struct IsConvertibleToBitsetImpl<B<N>>
+ : std::is_convertible<B<N>, std::bitset<N>> {};
+template <typename C>
+using IsConvertibleToBitset = IsConvertibleToBitsetImpl<absl::decay_t<C>>;
+
+template <typename C>
+struct IsConvertibleToSTLContainer
+ : absl::disjunction<
+ IsConvertibleToArray<C>, IsConvertibleToBitset<C>,
+ IsConvertibleToSpecialization<C, std::deque>,
+ IsConvertibleToSpecialization<C, std::forward_list>,
+ IsConvertibleToSpecialization<C, std::list>,
+ IsConvertibleToSpecialization<C, std::map>,
+ IsConvertibleToSpecialization<C, std::multimap>,
+ IsConvertibleToSpecialization<C, std::set>,
+ IsConvertibleToSpecialization<C, std::multiset>,
+ IsConvertibleToSpecialization<C, std::unordered_map>,
+ IsConvertibleToSpecialization<C, std::unordered_multimap>,
+ IsConvertibleToSpecialization<C, std::unordered_set>,
+ IsConvertibleToSpecialization<C, std::unordered_multiset>,
+ IsConvertibleToSpecialization<C, std::vector>> {};
+
+template <typename C>
+struct IsStrictlyBaseOfAndConvertibleToSTLContainer
+ : absl::conjunction<absl::negation<IsSTLContainer<C>>,
+ IsBaseOfSTLContainer<C>,
+ IsConvertibleToSTLContainer<C>> {};
+
+} // namespace strings_internal
+} // namespace absl
+#endif // ABSL_STRINGS_INTERNAL_STL_TYPE_TRAITS_H_
diff --git a/absl/strings/internal/str_format/arg.cc b/absl/strings/internal/str_format/arg.cc
new file mode 100644
index 0000000..b40be8f
--- /dev/null
+++ b/absl/strings/internal/str_format/arg.cc
@@ -0,0 +1,377 @@
+//
+// POSIX spec:
+// http://pubs.opengroup.org/onlinepubs/009695399/functions/fprintf.html
+//
+#include "absl/strings/internal/str_format/arg.h"
+
+#include <cassert>
+#include <cerrno>
+#include <cstdlib>
+#include <string>
+#include <type_traits>
+
+#include "absl/base/port.h"
+#include "absl/strings/internal/str_format/float_conversion.h"
+
+namespace absl {
+namespace str_format_internal {
+namespace {
+
+const char kDigit[2][32] = { "0123456789abcdef", "0123456789ABCDEF" };
+
+// Reduce *capacity by s.size(), clipped to a 0 minimum.
+void ReducePadding(string_view s, size_t *capacity) {
+ *capacity = Excess(s.size(), *capacity);
+}
+
+// Reduce *capacity by n, clipped to a 0 minimum.
+void ReducePadding(size_t n, size_t *capacity) {
+ *capacity = Excess(n, *capacity);
+}
+
+template <typename T>
+struct MakeUnsigned : std::make_unsigned<T> {};
+template <>
+struct MakeUnsigned<absl::uint128> {
+ using type = absl::uint128;
+};
+
+template <typename T>
+struct IsSigned : std::is_signed<T> {};
+template <>
+struct IsSigned<absl::uint128> : std::false_type {};
+
+class ConvertedIntInfo {
+ public:
+ template <typename T>
+ ConvertedIntInfo(T v, ConversionChar conv) {
+ using Unsigned = typename MakeUnsigned<T>::type;
+ auto u = static_cast<Unsigned>(v);
+ if (IsNeg(v)) {
+ is_neg_ = true;
+ u = Unsigned{} - u;
+ } else {
+ is_neg_ = false;
+ }
+ UnsignedToStringRight(u, conv);
+ }
+
+ string_view digits() const {
+ return {end() - size_, static_cast<size_t>(size_)};
+ }
+ bool is_neg() const { return is_neg_; }
+
+ private:
+ template <typename T, bool IsSigned>
+ struct IsNegImpl {
+ static bool Eval(T v) { return v < 0; }
+ };
+ template <typename T>
+ struct IsNegImpl<T, false> {
+ static bool Eval(T) {
+ return false;
+ }
+ };
+
+ template <typename T>
+ bool IsNeg(T v) {
+ return IsNegImpl<T, IsSigned<T>::value>::Eval(v);
+ }
+
+ template <typename T>
+ void UnsignedToStringRight(T u, ConversionChar conv) {
+ char *p = end();
+ switch (conv.radix()) {
+ default:
+ case 10:
+ for (; u; u /= 10)
+ *--p = static_cast<char>('0' + static_cast<size_t>(u % 10));
+ break;
+ case 8:
+ for (; u; u /= 8)
+ *--p = static_cast<char>('0' + static_cast<size_t>(u % 8));
+ break;
+ case 16: {
+ const char *digits = kDigit[conv.upper() ? 1 : 0];
+ for (; u; u /= 16) *--p = digits[static_cast<size_t>(u % 16)];
+ break;
+ }
+ }
+ size_ = static_cast<int>(end() - p);
+ }
+
+ const char *end() const { return storage_ + sizeof(storage_); }
+ char *end() { return storage_ + sizeof(storage_); }
+
+ bool is_neg_;
+ int size_;
+ // Max size: 128 bit value as octal -> 43 digits
+ char storage_[128 / 3 + 1];
+};
+
+// Note: 'o' conversions do not have a base indicator, it's just that
+// the '#' flag is specified to modify the precision for 'o' conversions.
+string_view BaseIndicator(const ConvertedIntInfo &info,
+ const ConversionSpec conv) {
+ bool alt = conv.flags().alt;
+ int radix = conv.conv().radix();
+ if (conv.conv().id() == ConversionChar::p)
+ alt = true; // always show 0x for %p.
+ // From the POSIX description of '#' flag:
+ // "For x or X conversion specifiers, a non-zero result shall have
+ // 0x (or 0X) prefixed to it."
+ if (alt && radix == 16 && !info.digits().empty()) {
+ if (conv.conv().upper()) return "0X";
+ return "0x";
+ }
+ return {};
+}
+
+string_view SignColumn(bool neg, const ConversionSpec conv) {
+ if (conv.conv().is_signed()) {
+ if (neg) return "-";
+ if (conv.flags().show_pos) return "+";
+ if (conv.flags().sign_col) return " ";
+ }
+ return {};
+}
+
+bool ConvertCharImpl(unsigned char v, const ConversionSpec conv,
+ FormatSinkImpl *sink) {
+ size_t fill = 0;
+ if (conv.width() >= 0) fill = conv.width();
+ ReducePadding(1, &fill);
+ if (!conv.flags().left) sink->Append(fill, ' ');
+ sink->Append(1, v);
+ if (conv.flags().left) sink->Append(fill, ' ');
+ return true;
+}
+
+bool ConvertIntImplInner(const ConvertedIntInfo &info,
+ const ConversionSpec conv, FormatSinkImpl *sink) {
+ // Print as a sequence of Substrings:
+ // [left_spaces][sign][base_indicator][zeroes][formatted][right_spaces]
+ size_t fill = 0;
+ if (conv.width() >= 0) fill = conv.width();
+
+ string_view formatted = info.digits();
+ ReducePadding(formatted, &fill);
+
+ string_view sign = SignColumn(info.is_neg(), conv);
+ ReducePadding(sign, &fill);
+
+ string_view base_indicator = BaseIndicator(info, conv);
+ ReducePadding(base_indicator, &fill);
+
+ int precision = conv.precision();
+ bool precision_specified = precision >= 0;
+ if (!precision_specified)
+ precision = 1;
+
+ if (conv.flags().alt && conv.conv().id() == ConversionChar::o) {
+ // From POSIX description of the '#' (alt) flag:
+ // "For o conversion, it increases the precision (if necessary) to
+ // force the first digit of the result to be zero."
+ if (formatted.empty() || *formatted.begin() != '0') {
+ int needed = static_cast<int>(formatted.size()) + 1;
+ precision = std::max(precision, needed);
+ }
+ }
+
+ size_t num_zeroes = Excess(formatted.size(), precision);
+ ReducePadding(num_zeroes, &fill);
+
+ size_t num_left_spaces = !conv.flags().left ? fill : 0;
+ size_t num_right_spaces = conv.flags().left ? fill : 0;
+
+ // From POSIX description of the '0' (zero) flag:
+ // "For d, i, o, u, x, and X conversion specifiers, if a precision
+ // is specified, the '0' flag is ignored."
+ if (!precision_specified && conv.flags().zero) {
+ num_zeroes += num_left_spaces;
+ num_left_spaces = 0;
+ }
+
+ sink->Append(num_left_spaces, ' ');
+ sink->Append(sign);
+ sink->Append(base_indicator);
+ sink->Append(num_zeroes, '0');
+ sink->Append(formatted);
+ sink->Append(num_right_spaces, ' ');
+ return true;
+}
+
+template <typename T>
+bool ConvertIntImplInner(T v, const ConversionSpec conv, FormatSinkImpl *sink) {
+ ConvertedIntInfo info(v, conv.conv());
+ if (conv.flags().basic && conv.conv().id() != ConversionChar::p) {
+ if (info.is_neg()) sink->Append(1, '-');
+ if (info.digits().empty()) {
+ sink->Append(1, '0');
+ } else {
+ sink->Append(info.digits());
+ }
+ return true;
+ }
+ return ConvertIntImplInner(info, conv, sink);
+}
+
+template <typename T>
+bool ConvertIntArg(T v, const ConversionSpec conv, FormatSinkImpl *sink) {
+ if (conv.conv().is_float()) {
+ return FormatConvertImpl(static_cast<double>(v), conv, sink).value;
+ }
+ if (conv.conv().id() == ConversionChar::c)
+ return ConvertCharImpl(static_cast<unsigned char>(v), conv, sink);
+ if (!conv.conv().is_integral())
+ return false;
+ if (!conv.conv().is_signed() && IsSigned<T>::value) {
+ using U = typename MakeUnsigned<T>::type;
+ return FormatConvertImpl(static_cast<U>(v), conv, sink).value;
+ }
+ return ConvertIntImplInner(v, conv, sink);
+}
+
+template <typename T>
+bool ConvertFloatArg(T v, const ConversionSpec conv, FormatSinkImpl *sink) {
+ return conv.conv().is_float() && ConvertFloatImpl(v, conv, sink);
+}
+
+inline bool ConvertStringArg(string_view v, const ConversionSpec conv,
+ FormatSinkImpl *sink) {
+ if (conv.conv().id() != ConversionChar::s)
+ return false;
+ if (conv.flags().basic) {
+ sink->Append(v);
+ return true;
+ }
+ return sink->PutPaddedString(v, conv.width(), conv.precision(),
+ conv.flags().left);
+}
+
+} // namespace
+
+// ==================== Strings ====================
+ConvertResult<Conv::s> FormatConvertImpl(const std::string &v,
+ const ConversionSpec conv,
+ FormatSinkImpl *sink) {
+ return {ConvertStringArg(v, conv, sink)};
+}
+
+ConvertResult<Conv::s> FormatConvertImpl(string_view v,
+ const ConversionSpec conv,
+ FormatSinkImpl *sink) {
+ return {ConvertStringArg(v, conv, sink)};
+}
+
+ConvertResult<Conv::s | Conv::p> FormatConvertImpl(const char *v,
+ const ConversionSpec conv,
+ FormatSinkImpl *sink) {
+ if (conv.conv().id() == ConversionChar::p)
+ return {FormatConvertImpl(VoidPtr(v), conv, sink).value};
+ size_t len;
+ if (v == nullptr) {
+ len = 0;
+ } else if (conv.precision() < 0) {
+ len = std::strlen(v);
+ } else {
+ // If precision is set, we look for the null terminator on the valid range.
+ len = std::find(v, v + conv.precision(), '\0') - v;
+ }
+ return {ConvertStringArg(string_view(v, len), conv, sink)};
+}
+
+// ==================== Raw pointers ====================
+ConvertResult<Conv::p> FormatConvertImpl(VoidPtr v, const ConversionSpec conv,
+ FormatSinkImpl *sink) {
+ if (conv.conv().id() != ConversionChar::p)
+ return {false};
+ if (!v.value) {
+ sink->Append("(nil)");
+ return {true};
+ }
+ return {ConvertIntImplInner(v.value, conv, sink)};
+}
+
+// ==================== Floats ====================
+FloatingConvertResult FormatConvertImpl(float v, const ConversionSpec conv,
+ FormatSinkImpl *sink) {
+ return {ConvertFloatArg(v, conv, sink)};
+}
+FloatingConvertResult FormatConvertImpl(double v, const ConversionSpec conv,
+ FormatSinkImpl *sink) {
+ return {ConvertFloatArg(v, conv, sink)};
+}
+FloatingConvertResult FormatConvertImpl(long double v,
+ const ConversionSpec conv,
+ FormatSinkImpl *sink) {
+ return {ConvertFloatArg(v, conv, sink)};
+}
+
+// ==================== Chars ====================
+IntegralConvertResult FormatConvertImpl(char v, const ConversionSpec conv,
+ FormatSinkImpl *sink) {
+ return {ConvertIntArg(v, conv, sink)};
+}
+IntegralConvertResult FormatConvertImpl(signed char v,
+ const ConversionSpec conv,
+ FormatSinkImpl *sink) {
+ return {ConvertIntArg(v, conv, sink)};
+}
+IntegralConvertResult FormatConvertImpl(unsigned char v,
+ const ConversionSpec conv,
+ FormatSinkImpl *sink) {
+ return {ConvertIntArg(v, conv, sink)};
+}
+
+// ==================== Ints ====================
+IntegralConvertResult FormatConvertImpl(short v, // NOLINT
+ const ConversionSpec conv,
+ FormatSinkImpl *sink) {
+ return {ConvertIntArg(v, conv, sink)};
+}
+IntegralConvertResult FormatConvertImpl(unsigned short v, // NOLINT
+ const ConversionSpec conv,
+ FormatSinkImpl *sink) {
+ return {ConvertIntArg(v, conv, sink)};
+}
+IntegralConvertResult FormatConvertImpl(int v, const ConversionSpec conv,
+ FormatSinkImpl *sink) {
+ return {ConvertIntArg(v, conv, sink)};
+}
+IntegralConvertResult FormatConvertImpl(unsigned v, const ConversionSpec conv,
+ FormatSinkImpl *sink) {
+ return {ConvertIntArg(v, conv, sink)};
+}
+IntegralConvertResult FormatConvertImpl(long v, // NOLINT
+ const ConversionSpec conv,
+ FormatSinkImpl *sink) {
+ return {ConvertIntArg(v, conv, sink)};
+}
+IntegralConvertResult FormatConvertImpl(unsigned long v, // NOLINT
+ const ConversionSpec conv,
+ FormatSinkImpl *sink) {
+ return {ConvertIntArg(v, conv, sink)};
+}
+IntegralConvertResult FormatConvertImpl(long long v, // NOLINT
+ const ConversionSpec conv,
+ FormatSinkImpl *sink) {
+ return {ConvertIntArg(v, conv, sink)};
+}
+IntegralConvertResult FormatConvertImpl(unsigned long long v, // NOLINT
+ const ConversionSpec conv,
+ FormatSinkImpl *sink) {
+ return {ConvertIntArg(v, conv, sink)};
+}
+IntegralConvertResult FormatConvertImpl(absl::uint128 v,
+ const ConversionSpec conv,
+ FormatSinkImpl *sink) {
+ return {ConvertIntArg(v, conv, sink)};
+}
+
+ABSL_INTERNAL_FORMAT_DISPATCH_OVERLOADS_EXPAND_();
+
+
+} // namespace str_format_internal
+
+} // namespace absl
diff --git a/absl/strings/internal/str_format/arg.h b/absl/strings/internal/str_format/arg.h
new file mode 100644
index 0000000..5cb3a14
--- /dev/null
+++ b/absl/strings/internal/str_format/arg.h
@@ -0,0 +1,424 @@
+#ifndef ABSL_STRINGS_INTERNAL_STR_FORMAT_ARG_H_
+#define ABSL_STRINGS_INTERNAL_STR_FORMAT_ARG_H_
+
+#include <string.h>
+#include <wchar.h>
+
+#include <cstdio>
+#include <iomanip>
+#include <limits>
+#include <memory>
+#include <sstream>
+#include <string>
+#include <type_traits>
+
+#include "absl/base/port.h"
+#include "absl/meta/type_traits.h"
+#include "absl/numeric/int128.h"
+#include "absl/strings/internal/str_format/extension.h"
+#include "absl/strings/string_view.h"
+
+class Cord;
+class CordReader;
+
+namespace absl {
+
+class FormatCountCapture;
+class FormatSink;
+
+namespace str_format_internal {
+
+template <typename T, typename = void>
+struct HasUserDefinedConvert : std::false_type {};
+
+template <typename T>
+struct HasUserDefinedConvert<
+ T, void_t<decltype(AbslFormatConvert(
+ std::declval<const T&>(), std::declval<ConversionSpec>(),
+ std::declval<FormatSink*>()))>> : std::true_type {};
+
+template <typename T>
+class StreamedWrapper;
+
+// If 'v' can be converted (in the printf sense) according to 'conv',
+// then convert it, appending to `sink` and return `true`.
+// Otherwise fail and return `false`.
+
+// Raw pointers.
+struct VoidPtr {
+ VoidPtr() = default;
+ template <typename T,
+ decltype(reinterpret_cast<uintptr_t>(std::declval<T*>())) = 0>
+ VoidPtr(T* ptr) // NOLINT
+ : value(ptr ? reinterpret_cast<uintptr_t>(ptr) : 0) {}
+ uintptr_t value;
+};
+ConvertResult<Conv::p> FormatConvertImpl(VoidPtr v, ConversionSpec conv,
+ FormatSinkImpl* sink);
+
+// Strings.
+ConvertResult<Conv::s> FormatConvertImpl(const std::string& v,
+ ConversionSpec conv,
+ FormatSinkImpl* sink);
+ConvertResult<Conv::s> FormatConvertImpl(string_view v, ConversionSpec conv,
+ FormatSinkImpl* sink);
+ConvertResult<Conv::s | Conv::p> FormatConvertImpl(const char* v,
+ ConversionSpec conv,
+ FormatSinkImpl* sink);
+template <class AbslCord,
+ typename std::enable_if<
+ std::is_same<AbslCord, ::Cord>::value>::type* = nullptr,
+ class AbslCordReader = ::CordReader>
+ConvertResult<Conv::s> FormatConvertImpl(const AbslCord& value,
+ ConversionSpec conv,
+ FormatSinkImpl* sink) {
+ if (conv.conv().id() != ConversionChar::s) return {false};
+
+ bool is_left = conv.flags().left;
+ size_t space_remaining = 0;
+
+ int width = conv.width();
+ if (width >= 0) space_remaining = width;
+
+ size_t to_write = value.size();
+
+ int precision = conv.precision();
+ if (precision >= 0)
+ to_write = (std::min)(to_write, static_cast<size_t>(precision));
+
+ space_remaining = Excess(to_write, space_remaining);
+
+ if (space_remaining > 0 && !is_left) sink->Append(space_remaining, ' ');
+
+ string_view piece;
+ for (AbslCordReader reader(value);
+ to_write > 0 && reader.ReadFragment(&piece); to_write -= piece.size()) {
+ if (piece.size() > to_write) piece.remove_suffix(piece.size() - to_write);
+ sink->Append(piece);
+ }
+
+ if (space_remaining > 0 && is_left) sink->Append(space_remaining, ' ');
+ return {true};
+}
+
+using IntegralConvertResult =
+ ConvertResult<Conv::c | Conv::numeric | Conv::star>;
+using FloatingConvertResult = ConvertResult<Conv::floating>;
+
+// Floats.
+FloatingConvertResult FormatConvertImpl(float v, ConversionSpec conv,
+ FormatSinkImpl* sink);
+FloatingConvertResult FormatConvertImpl(double v, ConversionSpec conv,
+ FormatSinkImpl* sink);
+FloatingConvertResult FormatConvertImpl(long double v, ConversionSpec conv,
+ FormatSinkImpl* sink);
+
+// Chars.
+IntegralConvertResult FormatConvertImpl(char v, ConversionSpec conv,
+ FormatSinkImpl* sink);
+IntegralConvertResult FormatConvertImpl(signed char v, ConversionSpec conv,
+ FormatSinkImpl* sink);
+IntegralConvertResult FormatConvertImpl(unsigned char v, ConversionSpec conv,
+ FormatSinkImpl* sink);
+
+// Ints.
+IntegralConvertResult FormatConvertImpl(short v, // NOLINT
+ ConversionSpec conv,
+ FormatSinkImpl* sink);
+IntegralConvertResult FormatConvertImpl(unsigned short v, // NOLINT
+ ConversionSpec conv,
+ FormatSinkImpl* sink);
+IntegralConvertResult FormatConvertImpl(int v, ConversionSpec conv,
+ FormatSinkImpl* sink);
+IntegralConvertResult FormatConvertImpl(unsigned v, ConversionSpec conv,
+ FormatSinkImpl* sink);
+IntegralConvertResult FormatConvertImpl(long v, // NOLINT
+ ConversionSpec conv,
+ FormatSinkImpl* sink);
+IntegralConvertResult FormatConvertImpl(unsigned long v, // NOLINT
+ ConversionSpec conv,
+ FormatSinkImpl* sink);
+IntegralConvertResult FormatConvertImpl(long long v, // NOLINT
+ ConversionSpec conv,
+ FormatSinkImpl* sink);
+IntegralConvertResult FormatConvertImpl(unsigned long long v, // NOLINT
+ ConversionSpec conv,
+ FormatSinkImpl* sink);
+IntegralConvertResult FormatConvertImpl(uint128 v, ConversionSpec conv,
+ FormatSinkImpl* sink);
+template <typename T, enable_if_t<std::is_same<T, bool>::value, int> = 0>
+IntegralConvertResult FormatConvertImpl(T v, ConversionSpec conv,
+ FormatSinkImpl* sink) {
+ return FormatConvertImpl(static_cast<int>(v), conv, sink);
+}
+
+// We provide this function to help the checker, but it is never defined.
+// FormatArgImpl will use the underlying Convert functions instead.
+template <typename T>
+typename std::enable_if<std::is_enum<T>::value &&
+ !HasUserDefinedConvert<T>::value,
+ IntegralConvertResult>::type
+FormatConvertImpl(T v, ConversionSpec conv, FormatSinkImpl* sink);
+
+template <typename T>
+ConvertResult<Conv::s> FormatConvertImpl(const StreamedWrapper<T>& v,
+ ConversionSpec conv,
+ FormatSinkImpl* out) {
+ std::ostringstream oss;
+ oss << v.v_;
+ if (!oss) return {false};
+ return str_format_internal::FormatConvertImpl(oss.str(), conv, out);
+}
+
+// Use templates and dependent types to delay evaluation of the function
+// until after FormatCountCapture is fully defined.
+struct FormatCountCaptureHelper {
+ template <class T = int>
+ static ConvertResult<Conv::n> ConvertHelper(const FormatCountCapture& v,
+ ConversionSpec conv,
+ FormatSinkImpl* sink) {
+ const absl::enable_if_t<sizeof(T) != 0, FormatCountCapture>& v2 = v;
+
+ if (conv.conv().id() != str_format_internal::ConversionChar::n)
+ return {false};
+ *v2.p_ = static_cast<int>(sink->size());
+ return {true};
+ }
+};
+
+template <class T = int>
+ConvertResult<Conv::n> FormatConvertImpl(const FormatCountCapture& v,
+ ConversionSpec conv,
+ FormatSinkImpl* sink) {
+ return FormatCountCaptureHelper::ConvertHelper(v, conv, sink);
+}
+
+// Helper friend struct to hide implementation details from the public API of
+// FormatArgImpl.
+struct FormatArgImplFriend {
+ template <typename Arg>
+ static bool ToInt(Arg arg, int* out) {
+ // A value initialized ConversionSpec has a `none` conv, which tells the
+ // dispatcher to run the `int` conversion.
+ return arg.dispatcher_(arg.data_, {}, out);
+ }
+
+ template <typename Arg>
+ static bool Convert(Arg arg, str_format_internal::ConversionSpec conv,
+ FormatSinkImpl* out) {
+ return arg.dispatcher_(arg.data_, conv, out);
+ }
+
+ template <typename Arg>
+ static typename Arg::Dispatcher GetVTablePtrForTest(Arg arg) {
+ return arg.dispatcher_;
+ }
+};
+
+// A type-erased handle to a format argument.
+class FormatArgImpl {
+ private:
+ enum { kInlinedSpace = 8 };
+
+ using VoidPtr = str_format_internal::VoidPtr;
+
+ union Data {
+ const void* ptr;
+ const volatile void* volatile_ptr;
+ char buf[kInlinedSpace];
+ };
+
+ using Dispatcher = bool (*)(Data, ConversionSpec, void* out);
+
+ template <typename T>
+ struct store_by_value
+ : std::integral_constant<bool, (sizeof(T) <= kInlinedSpace) &&
+ (std::is_integral<T>::value ||
+ std::is_floating_point<T>::value ||
+ std::is_pointer<T>::value ||
+ std::is_same<VoidPtr, T>::value)> {};
+
+ enum StoragePolicy { ByPointer, ByVolatilePointer, ByValue };
+ template <typename T>
+ struct storage_policy
+ : std::integral_constant<StoragePolicy,
+ (std::is_volatile<T>::value
+ ? ByVolatilePointer
+ : (store_by_value<T>::value ? ByValue
+ : ByPointer))> {
+ };
+
+ // To reduce the number of vtables we will decay values before hand.
+ // Anything with a user-defined Convert will get its own vtable.
+ // For everything else:
+ // - Decay char* and char arrays into `const char*`
+ // - Decay any other pointer to `const void*`
+ // - Decay all enums to their underlying type.
+ // - Decay function pointers to void*.
+ template <typename T, typename = void>
+ struct DecayType {
+ static constexpr bool kHasUserDefined =
+ str_format_internal::HasUserDefinedConvert<T>::value;
+ using type = typename std::conditional<
+ !kHasUserDefined && std::is_convertible<T, const char*>::value,
+ const char*,
+ typename std::conditional<!kHasUserDefined &&
+ std::is_convertible<T, VoidPtr>::value,
+ VoidPtr, const T&>::type>::type;
+ };
+ template <typename T>
+ struct DecayType<T,
+ typename std::enable_if<
+ !str_format_internal::HasUserDefinedConvert<T>::value &&
+ std::is_enum<T>::value>::type> {
+ using type = typename std::underlying_type<T>::type;
+ };
+
+ public:
+ template <typename T>
+ explicit FormatArgImpl(const T& value) {
+ using D = typename DecayType<T>::type;
+ static_assert(
+ std::is_same<D, const T&>::value || storage_policy<D>::value == ByValue,
+ "Decayed types must be stored by value");
+ Init(static_cast<D>(value));
+ }
+
+ private:
+ friend struct str_format_internal::FormatArgImplFriend;
+ template <typename T, StoragePolicy = storage_policy<T>::value>
+ struct Manager;
+
+ template <typename T>
+ struct Manager<T, ByPointer> {
+ static Data SetValue(const T& value) {
+ Data data;
+ data.ptr = std::addressof(value);
+ return data;
+ }
+
+ static const T& Value(Data arg) { return *static_cast<const T*>(arg.ptr); }
+ };
+
+ template <typename T>
+ struct Manager<T, ByVolatilePointer> {
+ static Data SetValue(const T& value) {
+ Data data;
+ data.volatile_ptr = &value;
+ return data;
+ }
+
+ static const T& Value(Data arg) {
+ return *static_cast<const T*>(arg.volatile_ptr);
+ }
+ };
+
+ template <typename T>
+ struct Manager<T, ByValue> {
+ static Data SetValue(const T& value) {
+ Data data;
+ memcpy(data.buf, &value, sizeof(value));
+ return data;
+ }
+
+ static T Value(Data arg) {
+ T value;
+ memcpy(&value, arg.buf, sizeof(T));
+ return value;
+ }
+ };
+
+ template <typename T>
+ void Init(const T& value) {
+ data_ = Manager<T>::SetValue(value);
+ dispatcher_ = &Dispatch<T>;
+ }
+
+ template <typename T>
+ static int ToIntVal(const T& val) {
+ using CommonType = typename std::conditional<std::is_signed<T>::value,
+ int64_t, uint64_t>::type;
+ if (static_cast<CommonType>(val) >
+ static_cast<CommonType>((std::numeric_limits<int>::max)())) {
+ return (std::numeric_limits<int>::max)();
+ } else if (std::is_signed<T>::value &&
+ static_cast<CommonType>(val) <
+ static_cast<CommonType>((std::numeric_limits<int>::min)())) {
+ return (std::numeric_limits<int>::min)();
+ }
+ return static_cast<int>(val);
+ }
+
+ template <typename T>
+ static bool ToInt(Data arg, int* out, std::true_type /* is_integral */,
+ std::false_type) {
+ *out = ToIntVal(Manager<T>::Value(arg));
+ return true;
+ }
+
+ template <typename T>
+ static bool ToInt(Data arg, int* out, std::false_type,
+ std::true_type /* is_enum */) {
+ *out = ToIntVal(static_cast<typename std::underlying_type<T>::type>(
+ Manager<T>::Value(arg)));
+ return true;
+ }
+
+ template <typename T>
+ static bool ToInt(Data, int*, std::false_type, std::false_type) {
+ return false;
+ }
+
+ template <typename T>
+ static bool Dispatch(Data arg, ConversionSpec spec, void* out) {
+ // A `none` conv indicates that we want the `int` conversion.
+ if (ABSL_PREDICT_FALSE(spec.conv().id() == ConversionChar::none)) {
+ return ToInt<T>(arg, static_cast<int*>(out), std::is_integral<T>(),
+ std::is_enum<T>());
+ }
+
+ return str_format_internal::FormatConvertImpl(
+ Manager<T>::Value(arg), spec, static_cast<FormatSinkImpl*>(out))
+ .value;
+ }
+
+ Data data_;
+ Dispatcher dispatcher_;
+};
+
+#define ABSL_INTERNAL_FORMAT_DISPATCH_INSTANTIATE_(T, E) \
+ E template bool FormatArgImpl::Dispatch<T>(Data, ConversionSpec, void*)
+
+#define ABSL_INTERNAL_FORMAT_DISPATCH_OVERLOADS_EXPAND_(...) \
+ ABSL_INTERNAL_FORMAT_DISPATCH_INSTANTIATE_(str_format_internal::VoidPtr, \
+ __VA_ARGS__); \
+ ABSL_INTERNAL_FORMAT_DISPATCH_INSTANTIATE_(bool, __VA_ARGS__); \
+ ABSL_INTERNAL_FORMAT_DISPATCH_INSTANTIATE_(char, __VA_ARGS__); \
+ ABSL_INTERNAL_FORMAT_DISPATCH_INSTANTIATE_(signed char, __VA_ARGS__); \
+ ABSL_INTERNAL_FORMAT_DISPATCH_INSTANTIATE_(unsigned char, __VA_ARGS__); \
+ ABSL_INTERNAL_FORMAT_DISPATCH_INSTANTIATE_(short, __VA_ARGS__); /* NOLINT */ \
+ ABSL_INTERNAL_FORMAT_DISPATCH_INSTANTIATE_(unsigned short, /* NOLINT */ \
+ __VA_ARGS__); \
+ ABSL_INTERNAL_FORMAT_DISPATCH_INSTANTIATE_(int, __VA_ARGS__); \
+ ABSL_INTERNAL_FORMAT_DISPATCH_INSTANTIATE_(unsigned int, __VA_ARGS__); \
+ ABSL_INTERNAL_FORMAT_DISPATCH_INSTANTIATE_(long, __VA_ARGS__); /* NOLINT */ \
+ ABSL_INTERNAL_FORMAT_DISPATCH_INSTANTIATE_(unsigned long, /* NOLINT */ \
+ __VA_ARGS__); \
+ ABSL_INTERNAL_FORMAT_DISPATCH_INSTANTIATE_(long long, /* NOLINT */ \
+ __VA_ARGS__); \
+ ABSL_INTERNAL_FORMAT_DISPATCH_INSTANTIATE_(unsigned long long, /* NOLINT */ \
+ __VA_ARGS__); \
+ ABSL_INTERNAL_FORMAT_DISPATCH_INSTANTIATE_(uint128, __VA_ARGS__); \
+ ABSL_INTERNAL_FORMAT_DISPATCH_INSTANTIATE_(float, __VA_ARGS__); \
+ ABSL_INTERNAL_FORMAT_DISPATCH_INSTANTIATE_(double, __VA_ARGS__); \
+ ABSL_INTERNAL_FORMAT_DISPATCH_INSTANTIATE_(long double, __VA_ARGS__); \
+ ABSL_INTERNAL_FORMAT_DISPATCH_INSTANTIATE_(const char*, __VA_ARGS__); \
+ ABSL_INTERNAL_FORMAT_DISPATCH_INSTANTIATE_(std::string, __VA_ARGS__); \
+ ABSL_INTERNAL_FORMAT_DISPATCH_INSTANTIATE_(string_view, __VA_ARGS__)
+
+ABSL_INTERNAL_FORMAT_DISPATCH_OVERLOADS_EXPAND_(extern);
+
+} // namespace str_format_internal
+} // namespace absl
+
+#endif // ABSL_STRINGS_INTERNAL_STR_FORMAT_ARG_H_
diff --git a/absl/strings/internal/str_format/arg_test.cc b/absl/strings/internal/str_format/arg_test.cc
new file mode 100644
index 0000000..3421fac
--- /dev/null
+++ b/absl/strings/internal/str_format/arg_test.cc
@@ -0,0 +1,111 @@
+// Copyright 2017 The Abseil Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// https://www.apache.org/licenses/LICENSE-2.0
+//
+#include "absl/strings/internal/str_format/arg.h"
+
+#include <ostream>
+#include <string>
+#include "gtest/gtest.h"
+#include "absl/strings/str_format.h"
+
+namespace absl {
+namespace str_format_internal {
+namespace {
+
+class FormatArgImplTest : public ::testing::Test {
+ public:
+ enum Color { kRed, kGreen, kBlue };
+
+ static const char *hi() { return "hi"; }
+};
+
+TEST_F(FormatArgImplTest, ToInt) {
+ int out = 0;
+ EXPECT_TRUE(FormatArgImplFriend::ToInt(FormatArgImpl(1), &out));
+ EXPECT_EQ(1, out);
+ EXPECT_TRUE(FormatArgImplFriend::ToInt(FormatArgImpl(-1), &out));
+ EXPECT_EQ(-1, out);
+ EXPECT_TRUE(
+ FormatArgImplFriend::ToInt(FormatArgImpl(static_cast<char>(64)), &out));
+ EXPECT_EQ(64, out);
+ EXPECT_TRUE(FormatArgImplFriend::ToInt(
+ FormatArgImpl(static_cast<unsigned long long>(123456)), &out)); // NOLINT
+ EXPECT_EQ(123456, out);
+ EXPECT_TRUE(FormatArgImplFriend::ToInt(
+ FormatArgImpl(static_cast<unsigned long long>( // NOLINT
+ std::numeric_limits<int>::max()) +
+ 1),
+ &out));
+ EXPECT_EQ(std::numeric_limits<int>::max(), out);
+ EXPECT_TRUE(FormatArgImplFriend::ToInt(
+ FormatArgImpl(static_cast<long long>( // NOLINT
+ std::numeric_limits<int>::min()) -
+ 10),
+ &out));
+ EXPECT_EQ(std::numeric_limits<int>::min(), out);
+ EXPECT_TRUE(FormatArgImplFriend::ToInt(FormatArgImpl(false), &out));
+ EXPECT_EQ(0, out);
+ EXPECT_TRUE(FormatArgImplFriend::ToInt(FormatArgImpl(true), &out));
+ EXPECT_EQ(1, out);
+ EXPECT_FALSE(FormatArgImplFriend::ToInt(FormatArgImpl(2.2), &out));
+ EXPECT_FALSE(FormatArgImplFriend::ToInt(FormatArgImpl(3.2f), &out));
+ EXPECT_FALSE(FormatArgImplFriend::ToInt(
+ FormatArgImpl(static_cast<int *>(nullptr)), &out));
+ EXPECT_FALSE(FormatArgImplFriend::ToInt(FormatArgImpl(hi()), &out));
+ EXPECT_FALSE(FormatArgImplFriend::ToInt(FormatArgImpl("hi"), &out));
+ EXPECT_TRUE(FormatArgImplFriend::ToInt(FormatArgImpl(kBlue), &out));
+ EXPECT_EQ(2, out);
+}
+
+extern const char kMyArray[];
+
+TEST_F(FormatArgImplTest, CharArraysDecayToCharPtr) {
+ const char* a = "";
+ EXPECT_EQ(FormatArgImplFriend::GetVTablePtrForTest(FormatArgImpl(a)),
+ FormatArgImplFriend::GetVTablePtrForTest(FormatArgImpl("")));
+ EXPECT_EQ(FormatArgImplFriend::GetVTablePtrForTest(FormatArgImpl(a)),
+ FormatArgImplFriend::GetVTablePtrForTest(FormatArgImpl("A")));
+ EXPECT_EQ(FormatArgImplFriend::GetVTablePtrForTest(FormatArgImpl(a)),
+ FormatArgImplFriend::GetVTablePtrForTest(FormatArgImpl("ABC")));
+ EXPECT_EQ(FormatArgImplFriend::GetVTablePtrForTest(FormatArgImpl(a)),
+ FormatArgImplFriend::GetVTablePtrForTest(FormatArgImpl(kMyArray)));
+}
+
+TEST_F(FormatArgImplTest, OtherPtrDecayToVoidPtr) {
+ auto expected = FormatArgImplFriend::GetVTablePtrForTest(
+ FormatArgImpl(static_cast<void *>(nullptr)));
+ EXPECT_EQ(FormatArgImplFriend::GetVTablePtrForTest(
+ FormatArgImpl(static_cast<int *>(nullptr))),
+ expected);
+ EXPECT_EQ(FormatArgImplFriend::GetVTablePtrForTest(
+ FormatArgImpl(static_cast<volatile int *>(nullptr))),
+ expected);
+
+ auto p = static_cast<void (*)()>([] {});
+ EXPECT_EQ(FormatArgImplFriend::GetVTablePtrForTest(FormatArgImpl(p)),
+ expected);
+}
+
+TEST_F(FormatArgImplTest, WorksWithCharArraysOfUnknownSize) {
+ std::string s;
+ FormatSinkImpl sink(&s);
+ ConversionSpec conv;
+ conv.set_conv(ConversionChar::FromChar('s'));
+ conv.set_flags(Flags());
+ conv.set_width(-1);
+ conv.set_precision(-1);
+ EXPECT_TRUE(
+ FormatArgImplFriend::Convert(FormatArgImpl(kMyArray), conv, &sink));
+ sink.Flush();
+ EXPECT_EQ("ABCDE", s);
+}
+const char kMyArray[] = "ABCDE";
+
+} // namespace
+} // namespace str_format_internal
+} // namespace absl
diff --git a/absl/strings/internal/str_format/bind.cc b/absl/strings/internal/str_format/bind.cc
new file mode 100644
index 0000000..a31859e
--- /dev/null
+++ b/absl/strings/internal/str_format/bind.cc
@@ -0,0 +1,230 @@
+#include "absl/strings/internal/str_format/bind.h"
+
+#include <cerrno>
+#include <limits>
+#include <sstream>
+#include <string>
+
+namespace absl {
+namespace str_format_internal {
+
+namespace {
+
+inline bool BindFromPosition(int position, int* value,
+ absl::Span<const FormatArgImpl> pack) {
+ assert(position > 0);
+ if (static_cast<size_t>(position) > pack.size()) {
+ return false;
+ }
+ // -1 because positions are 1-based
+ return FormatArgImplFriend::ToInt(pack[position - 1], value);
+}
+
+class ArgContext {
+ public:
+ explicit ArgContext(absl::Span<const FormatArgImpl> pack) : pack_(pack) {}
+
+ // Fill 'bound' with the results of applying the context's argument pack
+ // to the specified 'unbound'. We synthesize a BoundConversion by
+ // lining up a UnboundConversion with a user argument. We also
+ // resolve any '*' specifiers for width and precision, so after
+ // this call, 'bound' has all the information it needs to be formatted.
+ // Returns false on failure.
+ bool Bind(const UnboundConversion* unbound, BoundConversion* bound);
+
+ private:
+ absl::Span<const FormatArgImpl> pack_;
+};
+
+inline bool ArgContext::Bind(const UnboundConversion* unbound,
+ BoundConversion* bound) {
+ const FormatArgImpl* arg = nullptr;
+ int arg_position = unbound->arg_position;
+ if (static_cast<size_t>(arg_position - 1) >= pack_.size()) return false;
+ arg = &pack_[arg_position - 1]; // 1-based
+
+ if (!unbound->flags.basic) {
+ int width = unbound->width.value();
+ bool force_left = false;
+ if (unbound->width.is_from_arg()) {
+ if (!BindFromPosition(unbound->width.get_from_arg(), &width, pack_))
+ return false;
+ if (width < 0) {
+ // "A negative field width is taken as a '-' flag followed by a
+ // positive field width."
+ force_left = true;
+ // Make sure we don't overflow the width when negating it.
+ width = -std::max(width, -std::numeric_limits<int>::max());
+ }
+ }
+
+ int precision = unbound->precision.value();
+ if (unbound->precision.is_from_arg()) {
+ if (!BindFromPosition(unbound->precision.get_from_arg(), &precision,
+ pack_))
+ return false;
+ }
+
+ bound->set_width(width);
+ bound->set_precision(precision);
+ bound->set_flags(unbound->flags);
+ if (force_left)
+ bound->set_left(true);
+ } else {
+ bound->set_flags(unbound->flags);
+ bound->set_width(-1);
+ bound->set_precision(-1);
+ }
+
+ bound->set_length_mod(unbound->length_mod);
+ bound->set_conv(unbound->conv);
+ bound->set_arg(arg);
+ return true;
+}
+
+template <typename Converter>
+class ConverterConsumer {
+ public:
+ ConverterConsumer(Converter converter, absl::Span<const FormatArgImpl> pack)
+ : converter_(converter), arg_context_(pack) {}
+
+ bool Append(string_view s) {
+ converter_.Append(s);
+ return true;
+ }
+ bool ConvertOne(const UnboundConversion& conv, string_view conv_string) {
+ BoundConversion bound;
+ if (!arg_context_.Bind(&conv, &bound)) return false;
+ return converter_.ConvertOne(bound, conv_string);
+ }
+
+ private:
+ Converter converter_;
+ ArgContext arg_context_;
+};
+
+template <typename Converter>
+bool ConvertAll(const UntypedFormatSpecImpl format,
+ absl::Span<const FormatArgImpl> args, Converter converter) {
+ if (format.has_parsed_conversion()) {
+ return format.parsed_conversion()->ProcessFormat(
+ ConverterConsumer<Converter>(converter, args));
+ } else {
+ return ParseFormatString(format.str(),
+ ConverterConsumer<Converter>(converter, args));
+ }
+}
+
+class DefaultConverter {
+ public:
+ explicit DefaultConverter(FormatSinkImpl* sink) : sink_(sink) {}
+
+ void Append(string_view s) const { sink_->Append(s); }
+
+ bool ConvertOne(const BoundConversion& bound, string_view /*conv*/) const {
+ return FormatArgImplFriend::Convert(*bound.arg(), bound, sink_);
+ }
+
+ private:
+ FormatSinkImpl* sink_;
+};
+
+class SummarizingConverter {
+ public:
+ explicit SummarizingConverter(FormatSinkImpl* sink) : sink_(sink) {}
+
+ void Append(string_view s) const { sink_->Append(s); }
+
+ bool ConvertOne(const BoundConversion& bound, string_view /*conv*/) const {
+ UntypedFormatSpecImpl spec("%d");
+
+ std::ostringstream ss;
+ ss << "{" << Streamable(spec, {*bound.arg()}) << ":" << bound.flags();
+ if (bound.width() >= 0) ss << bound.width();
+ if (bound.precision() >= 0) ss << "." << bound.precision();
+ ss << bound.length_mod() << bound.conv() << "}";
+ Append(ss.str());
+ return true;
+ }
+
+ private:
+ FormatSinkImpl* sink_;
+};
+
+} // namespace
+
+bool BindWithPack(const UnboundConversion* props,
+ absl::Span<const FormatArgImpl> pack,
+ BoundConversion* bound) {
+ return ArgContext(pack).Bind(props, bound);
+}
+
+std::string Summarize(const UntypedFormatSpecImpl format,
+ absl::Span<const FormatArgImpl> args) {
+ typedef SummarizingConverter Converter;
+ std::string out;
+ {
+ // inner block to destroy sink before returning out. It ensures a last
+ // flush.
+ FormatSinkImpl sink(&out);
+ if (!ConvertAll(format, args, Converter(&sink))) {
+ return "";
+ }
+ }
+ return out;
+}
+
+bool FormatUntyped(FormatRawSinkImpl raw_sink,
+ const UntypedFormatSpecImpl format,
+ absl::Span<const FormatArgImpl> args) {
+ FormatSinkImpl sink(raw_sink);
+ using Converter = DefaultConverter;
+ return ConvertAll(format, args, Converter(&sink));
+}
+
+std::ostream& Streamable::Print(std::ostream& os) const {
+ if (!FormatUntyped(&os, format_, args_)) os.setstate(std::ios::failbit);
+ return os;
+}
+
+std::string& AppendPack(std::string* out, const UntypedFormatSpecImpl format,
+ absl::Span<const FormatArgImpl> args) {
+ size_t orig = out->size();
+ if (ABSL_PREDICT_FALSE(!FormatUntyped(out, format, args))) {
+ out->erase(orig);
+ }
+ return *out;
+}
+
+int FprintF(std::FILE* output, const UntypedFormatSpecImpl format,
+ absl::Span<const FormatArgImpl> args) {
+ FILERawSink sink(output);
+ if (!FormatUntyped(&sink, format, args)) {
+ errno = EINVAL;
+ return -1;
+ }
+ if (sink.error()) {
+ errno = sink.error();
+ return -1;
+ }
+ if (sink.count() > std::numeric_limits<int>::max()) {
+ errno = EFBIG;
+ return -1;
+ }
+ return static_cast<int>(sink.count());
+}
+
+int SnprintF(char* output, size_t size, const UntypedFormatSpecImpl format,
+ absl::Span<const FormatArgImpl> args) {
+ BufferRawSink sink(output, size ? size - 1 : 0);
+ if (!FormatUntyped(&sink, format, args)) {
+ errno = EINVAL;
+ return -1;
+ }
+ size_t total = sink.total_written();
+ if (size) output[std::min(total, size - 1)] = 0;
+ return static_cast<int>(total);
+}
+
+} // namespace str_format_internal
+} // namespace absl
diff --git a/absl/strings/internal/str_format/bind.h b/absl/strings/internal/str_format/bind.h
new file mode 100644
index 0000000..7df140a
--- /dev/null
+++ b/absl/strings/internal/str_format/bind.h
@@ -0,0 +1,211 @@
+#ifndef ABSL_STRINGS_INTERNAL_STR_FORMAT_BIND_H_
+#define ABSL_STRINGS_INTERNAL_STR_FORMAT_BIND_H_
+
+#include <array>
+#include <cstdio>
+#include <sstream>
+#include <string>
+
+#include "absl/base/port.h"
+#include "absl/strings/internal/str_format/arg.h"
+#include "absl/strings/internal/str_format/checker.h"
+#include "absl/strings/internal/str_format/parser.h"
+#include "absl/types/span.h"
+
+namespace absl {
+
+class UntypedFormatSpec;
+
+namespace str_format_internal {
+
+class BoundConversion : public ConversionSpec {
+ public:
+ const FormatArgImpl* arg() const { return arg_; }
+ void set_arg(const FormatArgImpl* a) { arg_ = a; }
+
+ private:
+ const FormatArgImpl* arg_;
+};
+
+// This is the type-erased class that the implementation uses.
+class UntypedFormatSpecImpl {
+ public:
+ UntypedFormatSpecImpl() = delete;
+
+ explicit UntypedFormatSpecImpl(string_view s)
+ : data_(s.data()), size_(s.size()) {}
+ explicit UntypedFormatSpecImpl(
+ const str_format_internal::ParsedFormatBase* pc)
+ : data_(pc), size_(~size_t{}) {}
+
+ bool has_parsed_conversion() const { return size_ == ~size_t{}; }
+
+ string_view str() const {
+ assert(!has_parsed_conversion());
+ return string_view(static_cast<const char*>(data_), size_);
+ }
+ const str_format_internal::ParsedFormatBase* parsed_conversion() const {
+ assert(has_parsed_conversion());
+ return static_cast<const str_format_internal::ParsedFormatBase*>(data_);
+ }
+
+ template <typename T>
+ static const UntypedFormatSpecImpl& Extract(const T& s) {
+ return s.spec_;
+ }
+
+ private:
+ const void* data_;
+ size_t size_;
+};
+
+template <typename T, typename...>
+struct MakeDependent {
+ using type = T;
+};
+
+// Implicitly convertible from `const char*`, `string_view`, and the
+// `ExtendedParsedFormat` type. This abstraction allows all format functions to
+// operate on any without providing too many overloads.
+template <typename... Args>
+class FormatSpecTemplate
+ : public MakeDependent<UntypedFormatSpec, Args...>::type {
+ using Base = typename MakeDependent<UntypedFormatSpec, Args...>::type;
+
+ public:
+#if ABSL_INTERNAL_ENABLE_FORMAT_CHECKER
+
+ // Honeypot overload for when the std::string is not constexpr.
+ // We use the 'unavailable' attribute to give a better compiler error than
+ // just 'method is deleted'.
+ FormatSpecTemplate(...) // NOLINT
+ __attribute__((unavailable("Format std::string is not constexpr.")));
+
+ // Honeypot overload for when the format is constexpr and invalid.
+ // We use the 'unavailable' attribute to give a better compiler error than
+ // just 'method is deleted'.
+ // To avoid checking the format twice, we just check that the format is
+ // constexpr. If is it valid, then the overload below will kick in.
+ // We add the template here to make this overload have lower priority.
+ template <typename = void>
+ FormatSpecTemplate(const char* s) // NOLINT
+ __attribute__((
+ enable_if(str_format_internal::EnsureConstexpr(s), "constexpr trap"),
+ unavailable(
+ "Format specified does not match the arguments passed.")));
+
+ template <typename T = void>
+ FormatSpecTemplate(string_view s) // NOLINT
+ __attribute__((enable_if(str_format_internal::EnsureConstexpr(s),
+ "constexpr trap"))) {
+ static_assert(sizeof(T*) == 0,
+ "Format specified does not match the arguments passed.");
+ }
+
+ // Good format overload.
+ FormatSpecTemplate(const char* s) // NOLINT
+ __attribute__((enable_if(ValidFormatImpl<ArgumentToConv<Args>()...>(s),
+ "bad format trap")))
+ : Base(s) {}
+
+ FormatSpecTemplate(string_view s) // NOLINT
+ __attribute__((enable_if(ValidFormatImpl<ArgumentToConv<Args>()...>(s),
+ "bad format trap")))
+ : Base(s) {}
+
+#else // ABSL_INTERNAL_ENABLE_FORMAT_CHECKER
+
+ FormatSpecTemplate(const char* s) : Base(s) {} // NOLINT
+ FormatSpecTemplate(string_view s) : Base(s) {} // NOLINT
+
+#endif // ABSL_INTERNAL_ENABLE_FORMAT_CHECKER
+
+ template <Conv... C, typename = typename std::enable_if<
+ sizeof...(C) == sizeof...(Args) &&
+ AllOf(Contains(ArgumentToConv<Args>(),
+ C)...)>::type>
+ FormatSpecTemplate(const ExtendedParsedFormat<C...>& pc) // NOLINT
+ : Base(&pc) {}
+};
+
+template <typename... Args>
+struct FormatSpecDeductionBarrier {
+ using type = FormatSpecTemplate<Args...>;
+};
+
+class Streamable {
+ public:
+ Streamable(const UntypedFormatSpecImpl& format,
+ absl::Span<const FormatArgImpl> args)
+ : format_(format) {
+ if (args.size() <= ABSL_ARRAYSIZE(few_args_)) {
+ for (size_t i = 0; i < args.size(); ++i) {
+ few_args_[i] = args[i];
+ }
+ args_ = absl::MakeSpan(few_args_, args.size());
+ } else {
+ many_args_.assign(args.begin(), args.end());
+ args_ = many_args_;
+ }
+ }
+
+ std::ostream& Print(std::ostream& os) const;
+
+ friend std::ostream& operator<<(std::ostream& os, const Streamable& l) {
+ return l.Print(os);
+ }
+
+ private:
+ const UntypedFormatSpecImpl& format_;
+ absl::Span<const FormatArgImpl> args_;
+ // if args_.size() is 4 or less:
+ FormatArgImpl few_args_[4] = {FormatArgImpl(0), FormatArgImpl(0),
+ FormatArgImpl(0), FormatArgImpl(0)};
+ // if args_.size() is more than 4:
+ std::vector<FormatArgImpl> many_args_;
+};
+
+// for testing
+std::string Summarize(UntypedFormatSpecImpl format,
+ absl::Span<const FormatArgImpl> args);
+bool BindWithPack(const UnboundConversion* props,
+ absl::Span<const FormatArgImpl> pack, BoundConversion* bound);
+
+bool FormatUntyped(FormatRawSinkImpl raw_sink,
+ UntypedFormatSpecImpl format,
+ absl::Span<const FormatArgImpl> args);
+
+std::string& AppendPack(std::string* out, UntypedFormatSpecImpl format,
+ absl::Span<const FormatArgImpl> args);
+
+inline std::string FormatPack(const UntypedFormatSpecImpl format,
+ absl::Span<const FormatArgImpl> args) {
+ std::string out;
+ AppendPack(&out, format, args);
+ return out;
+}
+
+int FprintF(std::FILE* output, UntypedFormatSpecImpl format,
+ absl::Span<const FormatArgImpl> args);
+int SnprintF(char* output, size_t size, UntypedFormatSpecImpl format,
+ absl::Span<const FormatArgImpl> args);
+
+// Returned by Streamed(v). Converts via '%s' to the std::string created
+// by std::ostream << v.
+template <typename T>
+class StreamedWrapper {
+ public:
+ explicit StreamedWrapper(const T& v) : v_(v) { }
+
+ private:
+ template <typename S>
+ friend ConvertResult<Conv::s> FormatConvertImpl(const StreamedWrapper<S>& v,
+ ConversionSpec conv,
+ FormatSinkImpl* out);
+ const T& v_;
+};
+
+} // namespace str_format_internal
+} // namespace absl
+
+#endif // ABSL_STRINGS_INTERNAL_STR_FORMAT_BIND_H_
diff --git a/absl/strings/internal/str_format/bind_test.cc b/absl/strings/internal/str_format/bind_test.cc
new file mode 100644
index 0000000..2574801
--- /dev/null
+++ b/absl/strings/internal/str_format/bind_test.cc
@@ -0,0 +1,141 @@
+#include "absl/strings/internal/str_format/bind.h"
+
+#include <string.h>
+#include <limits>
+
+#include "gtest/gtest.h"
+
+namespace absl {
+namespace str_format_internal {
+namespace {
+
+class FormatBindTest : public ::testing::Test {
+ public:
+ bool Extract(const char *s, UnboundConversion *props, int *next) const {
+ return ConsumeUnboundConversion(s, s + strlen(s), props, next) ==
+ s + strlen(s);
+ }
+};
+
+TEST_F(FormatBindTest, BindSingle) {
+ struct Expectation {
+ int line;
+ const char *fmt;
+ int ok_phases;
+ const FormatArgImpl *arg;
+ int width;
+ int precision;
+ int next_arg;
+ };
+ const int no = -1;
+ const int ia[] = { 10, 20, 30, 40};
+ const FormatArgImpl args[] = {FormatArgImpl(ia[0]), FormatArgImpl(ia[1]),
+ FormatArgImpl(ia[2]), FormatArgImpl(ia[3])};
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wmissing-field-initializers"
+ const Expectation kExpect[] = {
+ {__LINE__, "d", 2, &args[0], no, no, 2},
+ {__LINE__, "4d", 2, &args[0], 4, no, 2},
+ {__LINE__, ".5d", 2, &args[0], no, 5, 2},
+ {__LINE__, "4.5d", 2, &args[0], 4, 5, 2},
+ {__LINE__, "*d", 2, &args[1], 10, no, 3},
+ {__LINE__, ".*d", 2, &args[1], no, 10, 3},
+ {__LINE__, "*.*d", 2, &args[2], 10, 20, 4},
+ {__LINE__, "1$d", 2, &args[0], no, no, 0},
+ {__LINE__, "2$d", 2, &args[1], no, no, 0},
+ {__LINE__, "3$d", 2, &args[2], no, no, 0},
+ {__LINE__, "4$d", 2, &args[3], no, no, 0},
+ {__LINE__, "2$*1$d", 2, &args[1], 10, no, 0},
+ {__LINE__, "2$*2$d", 2, &args[1], 20, no, 0},
+ {__LINE__, "2$*3$d", 2, &args[1], 30, no, 0},
+ {__LINE__, "2$.*1$d", 2, &args[1], no, 10, 0},
+ {__LINE__, "2$.*2$d", 2, &args[1], no, 20, 0},
+ {__LINE__, "2$.*3$d", 2, &args[1], no, 30, 0},
+ {__LINE__, "2$*3$.*1$d", 2, &args[1], 30, 10, 0},
+ {__LINE__, "2$*2$.*2$d", 2, &args[1], 20, 20, 0},
+ {__LINE__, "2$*1$.*3$d", 2, &args[1], 10, 30, 0},
+ {__LINE__, "2$*3$.*1$d", 2, &args[1], 30, 10, 0},
+ {__LINE__, "1$*d", 0}, // indexed, then positional
+ {__LINE__, "*2$d", 0}, // positional, then indexed
+ {__LINE__, "6$d", 1}, // arg position out of bounds
+ {__LINE__, "1$6$d", 0}, // width position incorrectly specified
+ {__LINE__, "1$.6$d", 0}, // precision position incorrectly specified
+ {__LINE__, "1$*6$d", 1}, // width position out of bounds
+ {__LINE__, "1$.*6$d", 1}, // precision position out of bounds
+ };
+#pragma GCC diagnostic pop
+ for (const Expectation &e : kExpect) {
+ SCOPED_TRACE(e.line);
+ SCOPED_TRACE(e.fmt);
+ UnboundConversion props;
+ BoundConversion bound;
+ int ok_phases = 0;
+ int next = 0;
+ if (Extract(e.fmt, &props, &next)) {
+ ++ok_phases;
+ if (BindWithPack(&props, args, &bound)) {
+ ++ok_phases;
+ }
+ }
+ EXPECT_EQ(e.ok_phases, ok_phases);
+ if (e.ok_phases < 2) continue;
+ if (e.arg != nullptr) {
+ EXPECT_EQ(e.arg, bound.arg());
+ }
+ EXPECT_EQ(e.width, bound.width());
+ EXPECT_EQ(e.precision, bound.precision());
+ }
+}
+
+TEST_F(FormatBindTest, WidthUnderflowRegression) {
+ UnboundConversion props;
+ BoundConversion bound;
+ int next = 0;
+ const int args_i[] = {std::numeric_limits<int>::min(), 17};
+ const FormatArgImpl args[] = {FormatArgImpl(args_i[0]),
+ FormatArgImpl(args_i[1])};
+ ASSERT_TRUE(Extract("*d", &props, &next));
+ ASSERT_TRUE(BindWithPack(&props, args, &bound));
+
+ EXPECT_EQ(bound.width(), std::numeric_limits<int>::max());
+ EXPECT_EQ(bound.arg(), args + 1);
+}
+
+TEST_F(FormatBindTest, FormatPack) {
+ struct Expectation {
+ int line;
+ const char *fmt;
+ const char *summary;
+ };
+ const int ia[] = { 10, 20, 30, 40, -10 };
+ const FormatArgImpl args[] = {FormatArgImpl(ia[0]), FormatArgImpl(ia[1]),
+ FormatArgImpl(ia[2]), FormatArgImpl(ia[3]),
+ FormatArgImpl(ia[4])};
+ const Expectation kExpect[] = {
+ {__LINE__, "a%4db%dc", "a{10:4d}b{20:d}c"},
+ {__LINE__, "a%.4db%dc", "a{10:.4d}b{20:d}c"},
+ {__LINE__, "a%4.5db%dc", "a{10:4.5d}b{20:d}c"},
+ {__LINE__, "a%db%4.5dc", "a{10:d}b{20:4.5d}c"},
+ {__LINE__, "a%db%*.*dc", "a{10:d}b{40:20.30d}c"},
+ {__LINE__, "a%.*fb", "a{20:.10f}b"},
+ {__LINE__, "a%1$db%2$*3$.*4$dc", "a{10:d}b{20:30.40d}c"},
+ {__LINE__, "a%4$db%3$*2$.*1$dc", "a{40:d}b{30:20.10d}c"},
+ {__LINE__, "a%04ldb", "a{10:04ld}b"},
+ {__LINE__, "a%-#04lldb", "a{10:-#04lld}b"},
+ {__LINE__, "a%1$*5$db", "a{10:-10d}b"},
+ {__LINE__, "a%1$.*5$db", "a{10:d}b"},
+ };
+ for (const Expectation &e : kExpect) {
+ absl::string_view fmt = e.fmt;
+ SCOPED_TRACE(e.line);
+ SCOPED_TRACE(e.fmt);
+ UntypedFormatSpecImpl format(fmt);
+ EXPECT_EQ(e.summary,
+ str_format_internal::Summarize(format, absl::MakeSpan(args)))
+ << "line:" << e.line;
+ }
+}
+
+} // namespace
+} // namespace str_format_internal
+} // namespace absl
diff --git a/absl/strings/internal/str_format/checker.h b/absl/strings/internal/str_format/checker.h
new file mode 100644
index 0000000..8b594f2
--- /dev/null
+++ b/absl/strings/internal/str_format/checker.h
@@ -0,0 +1,325 @@
+#ifndef ABSL_STRINGS_INTERNAL_STR_FORMAT_CHECKER_H_
+#define ABSL_STRINGS_INTERNAL_STR_FORMAT_CHECKER_H_
+
+#include "absl/strings/internal/str_format/arg.h"
+#include "absl/strings/internal/str_format/extension.h"
+
+// Compile time check support for entry points.
+
+#ifndef ABSL_INTERNAL_ENABLE_FORMAT_CHECKER
+#if defined(__clang__) && !defined(__native_client__)
+#if __has_attribute(enable_if)
+#define ABSL_INTERNAL_ENABLE_FORMAT_CHECKER 1
+#endif // __has_attribute(enable_if)
+#endif // defined(__clang__) && !defined(__native_client__)
+#endif // ABSL_INTERNAL_ENABLE_FORMAT_CHECKER
+
+namespace absl {
+namespace str_format_internal {
+
+constexpr bool AllOf() { return true; }
+
+template <typename... T>
+constexpr bool AllOf(bool b, T... t) {
+ return b && AllOf(t...);
+}
+
+template <typename Arg>
+constexpr Conv ArgumentToConv() {
+ return decltype(str_format_internal::FormatConvertImpl(
+ std::declval<const Arg&>(), std::declval<const ConversionSpec&>(),
+ std::declval<FormatSinkImpl*>()))::kConv;
+}
+
+#if ABSL_INTERNAL_ENABLE_FORMAT_CHECKER
+
+constexpr bool ContainsChar(const char* chars, char c) {
+ return *chars == c || (*chars && ContainsChar(chars + 1, c));
+}
+
+// A constexpr compatible list of Convs.
+struct ConvList {
+ const Conv* array;
+ int count;
+
+ // We do the bound check here to avoid having to do it on the callers.
+ // Returning an empty Conv has the same effect as short circuiting because it
+ // will never match any conversion.
+ constexpr Conv operator[](int i) const {
+ return i < count ? array[i] : Conv{};
+ }
+
+ constexpr ConvList without_front() const {
+ return count != 0 ? ConvList{array + 1, count - 1} : *this;
+ }
+};
+
+template <size_t count>
+struct ConvListT {
+ // Make sure the array has size > 0.
+ Conv list[count ? count : 1];
+};
+
+constexpr char GetChar(string_view str, size_t index) {
+ return index < str.size() ? str[index] : char{};
+}
+
+constexpr string_view ConsumeFront(string_view str, size_t len = 1) {
+ return len <= str.size() ? string_view(str.data() + len, str.size() - len)
+ : string_view();
+}
+
+constexpr string_view ConsumeAnyOf(string_view format, const char* chars) {
+ return ContainsChar(chars, GetChar(format, 0))
+ ? ConsumeAnyOf(ConsumeFront(format), chars)
+ : format;
+}
+
+constexpr bool IsDigit(char c) { return c >= '0' && c <= '9'; }
+
+// Helper class for the ParseDigits function.
+// It encapsulates the two return values we need there.
+struct Integer {
+ string_view format;
+ int value;
+
+ // If the next character is a '$', consume it.
+ // Otherwise, make `this` an invalid positional argument.
+ constexpr Integer ConsumePositionalDollar() const {
+ return GetChar(format, 0) == '$' ? Integer{ConsumeFront(format), value}
+ : Integer{format, 0};
+ }
+};
+
+constexpr Integer ParseDigits(string_view format, int value = 0) {
+ return IsDigit(GetChar(format, 0))
+ ? ParseDigits(ConsumeFront(format),
+ 10 * value + GetChar(format, 0) - '0')
+ : Integer{format, value};
+}
+
+// Parse digits for a positional argument.
+// The parsing also consumes the '$'.
+constexpr Integer ParsePositional(string_view format) {
+ return ParseDigits(format).ConsumePositionalDollar();
+}
+
+// Parses a single conversion specifier.
+// See ConvParser::Run() for post conditions.
+class ConvParser {
+ constexpr ConvParser SetFormat(string_view format) const {
+ return ConvParser(format, args_, error_, arg_position_, is_positional_);
+ }
+
+ constexpr ConvParser SetArgs(ConvList args) const {
+ return ConvParser(format_, args, error_, arg_position_, is_positional_);
+ }
+
+ constexpr ConvParser SetError(bool error) const {
+ return ConvParser(format_, args_, error_ || error, arg_position_,
+ is_positional_);
+ }
+
+ constexpr ConvParser SetArgPosition(int arg_position) const {
+ return ConvParser(format_, args_, error_, arg_position, is_positional_);
+ }
+
+ // Consumes the next arg and verifies that it matches `conv`.
+ // `error_` is set if there is no next arg or if it doesn't match `conv`.
+ constexpr ConvParser ConsumeNextArg(char conv) const {
+ return SetArgs(args_.without_front()).SetError(!Contains(args_[0], conv));
+ }
+
+ // Verify that positional argument `i.value` matches `conv`.
+ // `error_` is set if `i.value` is not a valid argument or if it doesn't
+ // match.
+ constexpr ConvParser VerifyPositional(Integer i, char conv) const {
+ return SetFormat(i.format).SetError(!Contains(args_[i.value - 1], conv));
+ }
+
+ // Parse the position of the arg and store it in `arg_position_`.
+ constexpr ConvParser ParseArgPosition(Integer arg) const {
+ return SetFormat(arg.format).SetArgPosition(arg.value);
+ }
+
+ // Consume the flags.
+ constexpr ConvParser ParseFlags() const {
+ return SetFormat(ConsumeAnyOf(format_, "-+ #0"));
+ }
+
+ // Consume the width.
+ // If it is '*', we verify that it matches `args_`. `error_` is set if it
+ // doesn't match.
+ constexpr ConvParser ParseWidth() const {
+ return IsDigit(GetChar(format_, 0))
+ ? SetFormat(ParseDigits(format_).format)
+ : GetChar(format_, 0) == '*'
+ ? is_positional_
+ ? VerifyPositional(
+ ParsePositional(ConsumeFront(format_)), '*')
+ : SetFormat(ConsumeFront(format_))
+ .ConsumeNextArg('*')
+ : *this;
+ }
+
+ // Consume the precision.
+ // If it is '*', we verify that it matches `args_`. `error_` is set if it
+ // doesn't match.
+ constexpr ConvParser ParsePrecision() const {
+ return GetChar(format_, 0) != '.'
+ ? *this
+ : GetChar(format_, 1) == '*'
+ ? is_positional_
+ ? VerifyPositional(
+ ParsePositional(ConsumeFront(format_, 2)), '*')
+ : SetFormat(ConsumeFront(format_, 2))
+ .ConsumeNextArg('*')
+ : SetFormat(ParseDigits(ConsumeFront(format_)).format);
+ }
+
+ // Consume the length characters.
+ constexpr ConvParser ParseLength() const {
+ return SetFormat(ConsumeAnyOf(format_, "lLhjztq"));
+ }
+
+ // Consume the conversion character and verify that it matches `args_`.
+ // `error_` is set if it doesn't match.
+ constexpr ConvParser ParseConversion() const {
+ return is_positional_
+ ? VerifyPositional({ConsumeFront(format_), arg_position_},
+ GetChar(format_, 0))
+ : ConsumeNextArg(GetChar(format_, 0))
+ .SetFormat(ConsumeFront(format_));
+ }
+
+ constexpr ConvParser(string_view format, ConvList args, bool error,
+ int arg_position, bool is_positional)
+ : format_(format),
+ args_(args),
+ error_(error),
+ arg_position_(arg_position),
+ is_positional_(is_positional) {}
+
+ public:
+ constexpr ConvParser(string_view format, ConvList args, bool is_positional)
+ : format_(format),
+ args_(args),
+ error_(false),
+ arg_position_(0),
+ is_positional_(is_positional) {}
+
+ // Consume the whole conversion specifier.
+ // `format()` will be set to the character after the conversion character.
+ // `error()` will be set if any of the arguments do not match.
+ constexpr ConvParser Run() const {
+ return (is_positional_ ? ParseArgPosition(ParsePositional(format_)) : *this)
+ .ParseFlags()
+ .ParseWidth()
+ .ParsePrecision()
+ .ParseLength()
+ .ParseConversion();
+ }
+
+ constexpr string_view format() const { return format_; }
+ constexpr ConvList args() const { return args_; }
+ constexpr bool error() const { return error_; }
+ constexpr bool is_positional() const { return is_positional_; }
+
+ private:
+ string_view format_;
+ // Current list of arguments. If we are not in positional mode we will consume
+ // from the front.
+ ConvList args_;
+ bool error_;
+ // Holds the argument position of the conversion character, if we are in
+ // positional mode. Otherwise, it is unspecified.
+ int arg_position_;
+ // Whether we are in positional mode.
+ // It changes the behavior of '*' and where to find the converted argument.
+ bool is_positional_;
+};
+
+// Parses a whole format expression.
+// See FormatParser::Run().
+class FormatParser {
+ static constexpr bool FoundPercent(string_view format) {
+ return format.empty() ||
+ (GetChar(format, 0) == '%' && GetChar(format, 1) != '%');
+ }
+
+ // We use an inner function to increase the recursion limit.
+ // The inner function consumes up to `limit` characters on every run.
+ // This increases the limit from 512 to ~512*limit.
+ static constexpr string_view ConsumeNonPercentInner(string_view format,
+ int limit = 20) {
+ return FoundPercent(format) || !limit
+ ? format
+ : ConsumeNonPercentInner(
+ ConsumeFront(format, GetChar(format, 0) == '%' &&
+ GetChar(format, 1) == '%'
+ ? 2
+ : 1),
+ limit - 1);
+ }
+
+ // Consume characters until the next conversion spec %.
+ // It skips %%.
+ static constexpr string_view ConsumeNonPercent(string_view format) {
+ return FoundPercent(format)
+ ? format
+ : ConsumeNonPercent(ConsumeNonPercentInner(format));
+ }
+
+ static constexpr bool IsPositional(string_view format) {
+ return IsDigit(GetChar(format, 0)) ? IsPositional(ConsumeFront(format))
+ : GetChar(format, 0) == '$';
+ }
+
+ constexpr bool RunImpl(bool is_positional) const {
+ // In non-positional mode we require all arguments to be consumed.
+ // In positional mode just reaching the end of the format without errors is
+ // enough.
+ return (format_.empty() && (is_positional || args_.count == 0)) ||
+ (!format_.empty() &&
+ ValidateArg(
+ ConvParser(ConsumeFront(format_), args_, is_positional).Run()));
+ }
+
+ constexpr bool ValidateArg(ConvParser conv) const {
+ return !conv.error() && FormatParser(conv.format(), conv.args())
+ .RunImpl(conv.is_positional());
+ }
+
+ public:
+ constexpr FormatParser(string_view format, ConvList args)
+ : format_(ConsumeNonPercent(format)), args_(args) {}
+
+ // Runs the parser for `format` and `args`.
+ // It verifies that the format is valid and that all conversion specifiers
+ // match the arguments passed.
+ // In non-positional mode it also verfies that all arguments are consumed.
+ constexpr bool Run() const {
+ return RunImpl(!format_.empty() && IsPositional(ConsumeFront(format_)));
+ }
+
+ private:
+ string_view format_;
+ // Current list of arguments.
+ // If we are not in positional mode we will consume from the front and will
+ // have to be empty in the end.
+ ConvList args_;
+};
+
+template <Conv... C>
+constexpr bool ValidFormatImpl(string_view format) {
+ return FormatParser(format,
+ {ConvListT<sizeof...(C)>{{C...}}.list, sizeof...(C)})
+ .Run();
+}
+
+#endif // ABSL_INTERNAL_ENABLE_FORMAT_CHECKER
+
+} // namespace str_format_internal
+} // namespace absl
+
+#endif // ABSL_STRINGS_INTERNAL_STR_FORMAT_CHECKER_H_
diff --git a/absl/strings/internal/str_format/checker_test.cc b/absl/strings/internal/str_format/checker_test.cc
new file mode 100644
index 0000000..c1d8c76
--- /dev/null
+++ b/absl/strings/internal/str_format/checker_test.cc
@@ -0,0 +1,150 @@
+#include <string>
+
+#include "gmock/gmock.h"
+#include "gtest/gtest.h"
+#include "absl/strings/str_format.h"
+
+namespace absl {
+namespace str_format_internal {
+namespace {
+
+std::string ConvToString(Conv conv) {
+ std::string out;
+#define CONV_SET_CASE(c) \
+ if (Contains(conv, Conv::c)) out += #c;
+ ABSL_CONVERSION_CHARS_EXPAND_(CONV_SET_CASE, )
+#undef CONV_SET_CASE
+ if (Contains(conv, Conv::star)) out += "*";
+ return out;
+}
+
+TEST(StrFormatChecker, ArgumentToConv) {
+ Conv conv = ArgumentToConv<std::string>();
+ EXPECT_EQ(ConvToString(conv), "s");
+
+ conv = ArgumentToConv<const char*>();
+ EXPECT_EQ(ConvToString(conv), "sp");
+
+ conv = ArgumentToConv<double>();
+ EXPECT_EQ(ConvToString(conv), "fFeEgGaA");
+
+ conv = ArgumentToConv<int>();
+ EXPECT_EQ(ConvToString(conv), "cdiouxXfFeEgGaA*");
+
+ conv = ArgumentToConv<std::string*>();
+ EXPECT_EQ(ConvToString(conv), "p");
+}
+
+#if ABSL_INTERNAL_ENABLE_FORMAT_CHECKER
+
+struct Case {
+ bool result;
+ const char* format;
+};
+
+template <typename... Args>
+constexpr Case ValidFormat(const char* format) {
+ return {ValidFormatImpl<ArgumentToConv<Args>()...>(format), format};
+}
+
+TEST(StrFormatChecker, ValidFormat) {
+ // We want to make sure these expressions are constexpr and they have the
+ // expected value.
+ // If they are not constexpr the attribute will just ignore them and not give
+ // a compile time error.
+ enum e {};
+ enum class e2 {};
+ constexpr Case trues[] = {
+ ValidFormat<>("abc"), //
+
+ ValidFormat<e>("%d"), //
+ ValidFormat<e2>("%d"), //
+ ValidFormat<int>("%% %d"), //
+ ValidFormat<int>("%ld"), //
+ ValidFormat<int>("%lld"), //
+ ValidFormat<std::string>("%s"), //
+ ValidFormat<std::string>("%10s"), //
+ ValidFormat<int>("%.10x"), //
+ ValidFormat<int, int>("%*.3x"), //
+ ValidFormat<int>("%1.d"), //
+ ValidFormat<int>("%.d"), //
+ ValidFormat<int, double>("%d %g"), //
+ ValidFormat<int, std::string>("%*s"), //
+ ValidFormat<int, double>("%.*f"), //
+ ValidFormat<void (*)(), volatile int*>("%p %p"), //
+ ValidFormat<string_view, const char*, double, void*>(
+ "string_view=%s const char*=%s double=%f void*=%p)"),
+
+ ValidFormat<int>("%% %1$d"), //
+ ValidFormat<int>("%1$ld"), //
+ ValidFormat<int>("%1$lld"), //
+ ValidFormat<std::string>("%1$s"), //
+ ValidFormat<std::string>("%1$10s"), //
+ ValidFormat<int>("%1$.10x"), //
+ ValidFormat<int>("%1$*1$.*1$d"), //
+ ValidFormat<int, int>("%1$*2$.3x"), //
+ ValidFormat<int>("%1$1.d"), //
+ ValidFormat<int>("%1$.d"), //
+ ValidFormat<double, int>("%2$d %1$g"), //
+ ValidFormat<int, std::string>("%2$*1$s"), //
+ ValidFormat<int, double>("%2$.*1$f"), //
+ ValidFormat<void*, string_view, const char*, double>(
+ "string_view=%2$s const char*=%3$s double=%4$f void*=%1$p "
+ "repeat=%3$s)")};
+
+ for (Case c : trues) {
+ EXPECT_TRUE(c.result) << c.format;
+ }
+
+ constexpr Case falses[] = {
+ ValidFormat<int>(""), //
+
+ ValidFormat<e>("%s"), //
+ ValidFormat<e2>("%s"), //
+ ValidFormat<>("%s"), //
+ ValidFormat<>("%r"), //
+ ValidFormat<int>("%s"), //
+ ValidFormat<int>("%.1.d"), //
+ ValidFormat<int>("%*1d"), //
+ ValidFormat<int>("%1-d"), //
+ ValidFormat<std::string, int>("%*s"), //
+ ValidFormat<int>("%*d"), //
+ ValidFormat<std::string>("%p"), //
+ ValidFormat<int (*)(int)>("%d"), //
+
+ ValidFormat<>("%3$d"), //
+ ValidFormat<>("%1$r"), //
+ ValidFormat<int>("%1$s"), //
+ ValidFormat<int>("%1$.1.d"), //
+ ValidFormat<int>("%1$*2$1d"), //
+ ValidFormat<int>("%1$1-d"), //
+ ValidFormat<std::string, int>("%2$*1$s"), //
+ ValidFormat<std::string>("%1$p"),
+
+ ValidFormat<int, int>("%d %2$d"), //
+ };
+
+ for (Case c : falses) {
+ EXPECT_FALSE(c.result) << c.format;
+ }
+}
+
+TEST(StrFormatChecker, LongFormat) {
+#define CHARS_X_40 "1234567890123456789012345678901234567890"
+#define CHARS_X_400 \
+ CHARS_X_40 CHARS_X_40 CHARS_X_40 CHARS_X_40 CHARS_X_40 CHARS_X_40 CHARS_X_40 \
+ CHARS_X_40 CHARS_X_40 CHARS_X_40
+#define CHARS_X_4000 \
+ CHARS_X_400 CHARS_X_400 CHARS_X_400 CHARS_X_400 CHARS_X_400 CHARS_X_400 \
+ CHARS_X_400 CHARS_X_400 CHARS_X_400 CHARS_X_400
+ constexpr char long_format[] =
+ CHARS_X_4000 "%d" CHARS_X_4000 "%s" CHARS_X_4000;
+ constexpr bool is_valid = ValidFormat<int, std::string>(long_format).result;
+ EXPECT_TRUE(is_valid);
+}
+
+#endif // ABSL_INTERNAL_ENABLE_FORMAT_CHECKER
+
+} // namespace
+} // namespace str_format_internal
+} // namespace absl
diff --git a/absl/strings/internal/str_format/convert_test.cc b/absl/strings/internal/str_format/convert_test.cc
new file mode 100644
index 0000000..814ccf4
--- /dev/null
+++ b/absl/strings/internal/str_format/convert_test.cc
@@ -0,0 +1,590 @@
+#include <errno.h>
+#include <stdarg.h>
+#include <stdio.h>
+#include <cctype>
+#include <cmath>
+#include <string>
+
+#include "gtest/gtest.h"
+#include "absl/strings/internal/str_format/bind.h"
+
+namespace absl {
+namespace str_format_internal {
+namespace {
+
+template <typename T, size_t N>
+size_t ArraySize(T (&)[N]) {
+ return N;
+}
+
+std::string LengthModFor(float) { return ""; }
+std::string LengthModFor(double) { return ""; }
+std::string LengthModFor(long double) { return "L"; }
+std::string LengthModFor(char) { return "hh"; }
+std::string LengthModFor(signed char) { return "hh"; }
+std::string LengthModFor(unsigned char) { return "hh"; }
+std::string LengthModFor(short) { return "h"; } // NOLINT
+std::string LengthModFor(unsigned short) { return "h"; } // NOLINT
+std::string LengthModFor(int) { return ""; }
+std::string LengthModFor(unsigned) { return ""; }
+std::string LengthModFor(long) { return "l"; } // NOLINT
+std::string LengthModFor(unsigned long) { return "l"; } // NOLINT
+std::string LengthModFor(long long) { return "ll"; } // NOLINT
+std::string LengthModFor(unsigned long long) { return "ll"; } // NOLINT
+
+std::string EscCharImpl(int v) {
+ if (std::isprint(static_cast<unsigned char>(v))) {
+ return std::string(1, static_cast<char>(v));
+ }
+ char buf[64];
+ int n = snprintf(buf, sizeof(buf), "\\%#.2x",
+ static_cast<unsigned>(v & 0xff));
+ assert(n > 0 && n < sizeof(buf));
+ return std::string(buf, n);
+}
+
+std::string Esc(char v) { return EscCharImpl(v); }
+std::string Esc(signed char v) { return EscCharImpl(v); }
+std::string Esc(unsigned char v) { return EscCharImpl(v); }
+
+template <typename T>
+std::string Esc(const T &v) {
+ std::ostringstream oss;
+ oss << v;
+ return oss.str();
+}
+
+void StrAppend(std::string *dst, const char *format, va_list ap) {
+ // First try with a small fixed size buffer
+ static const int kSpaceLength = 1024;
+ char space[kSpaceLength];
+
+ // It's possible for methods that use a va_list to invalidate
+ // the data in it upon use. The fix is to make a copy
+ // of the structure before using it and use that copy instead.
+ va_list backup_ap;
+ va_copy(backup_ap, ap);
+ int result = vsnprintf(space, kSpaceLength, format, backup_ap);
+ va_end(backup_ap);
+ if (result < kSpaceLength) {
+ if (result >= 0) {
+ // Normal case -- everything fit.
+ dst->append(space, result);
+ return;
+ }
+ if (result < 0) {
+ // Just an error.
+ return;
+ }
+ }
+
+ // Increase the buffer size to the size requested by vsnprintf,
+ // plus one for the closing \0.
+ int length = result + 1;
+ char *buf = new char[length];
+
+ // Restore the va_list before we use it again
+ va_copy(backup_ap, ap);
+ result = vsnprintf(buf, length, format, backup_ap);
+ va_end(backup_ap);
+
+ if (result >= 0 && result < length) {
+ // It fit
+ dst->append(buf, result);
+ }
+ delete[] buf;
+}
+
+std::string StrPrint(const char *format, ...) {
+ va_list ap;
+ va_start(ap, format);
+ std::string result;
+ StrAppend(&result, format, ap);
+ va_end(ap);
+ return result;
+}
+
+class FormatConvertTest : public ::testing::Test { };
+
+template <typename T>
+void TestStringConvert(const T& str) {
+ const FormatArgImpl args[] = {FormatArgImpl(str)};
+ struct Expectation {
+ const char *out;
+ const char *fmt;
+ };
+ const Expectation kExpect[] = {
+ {"hello", "%1$s" },
+ {"", "%1$.s" },
+ {"", "%1$.0s" },
+ {"h", "%1$.1s" },
+ {"he", "%1$.2s" },
+ {"hello", "%1$.10s" },
+ {" hello", "%1$6s" },
+ {" he", "%1$5.2s" },
+ {"he ", "%1$-5.2s" },
+ {"hello ", "%1$-6.10s" },
+ };
+ for (const Expectation &e : kExpect) {
+ UntypedFormatSpecImpl format(e.fmt);
+ EXPECT_EQ(e.out, FormatPack(format, absl::MakeSpan(args)));
+ }
+}
+
+TEST_F(FormatConvertTest, BasicString) {
+ TestStringConvert("hello"); // As char array.
+ TestStringConvert(static_cast<const char*>("hello"));
+ TestStringConvert(std::string("hello"));
+ TestStringConvert(string_view("hello"));
+}
+
+TEST_F(FormatConvertTest, NullString) {
+ const char* p = nullptr;
+ UntypedFormatSpecImpl format("%s");
+ EXPECT_EQ("", FormatPack(format, {FormatArgImpl(p)}));
+}
+
+TEST_F(FormatConvertTest, StringPrecision) {
+ // We cap at the precision.
+ char c = 'a';
+ const char* p = &c;
+ UntypedFormatSpecImpl format("%.1s");
+ EXPECT_EQ("a", FormatPack(format, {FormatArgImpl(p)}));
+
+ // We cap at the nul terminator.
+ p = "ABC";
+ UntypedFormatSpecImpl format2("%.10s");
+ EXPECT_EQ("ABC", FormatPack(format2, {FormatArgImpl(p)}));
+}
+
+TEST_F(FormatConvertTest, Pointer) {
+#ifdef _MSC_VER
+ // MSVC's printf implementation prints pointers differently. We can't easily
+ // compare our implementation to theirs.
+ return;
+#endif
+ static int x = 0;
+ const int *xp = &x;
+ char c = 'h';
+ char *mcp = &c;
+ const char *cp = "hi";
+ const char *cnil = nullptr;
+ const int *inil = nullptr;
+ using VoidF = void (*)();
+ VoidF fp = [] {}, fnil = nullptr;
+ volatile char vc;
+ volatile char* vcp = &vc;
+ volatile char* vcnil = nullptr;
+ const FormatArgImpl args[] = {
+ FormatArgImpl(xp), FormatArgImpl(cp), FormatArgImpl(inil),
+ FormatArgImpl(cnil), FormatArgImpl(mcp), FormatArgImpl(fp),
+ FormatArgImpl(fnil), FormatArgImpl(vcp), FormatArgImpl(vcnil),
+ };
+ struct Expectation {
+ std::string out;
+ const char *fmt;
+ };
+ const Expectation kExpect[] = {
+ {StrPrint("%p", &x), "%p"},
+ {StrPrint("%20p", &x), "%20p"},
+ {StrPrint("%.1p", &x), "%.1p"},
+ {StrPrint("%.20p", &x), "%.20p"},
+ {StrPrint("%30.20p", &x), "%30.20p"},
+
+ {StrPrint("%-p", &x), "%-p"},
+ {StrPrint("%-20p", &x), "%-20p"},
+ {StrPrint("%-.1p", &x), "%-.1p"},
+ {StrPrint("%.20p", &x), "%.20p"},
+ {StrPrint("%-30.20p", &x), "%-30.20p"},
+
+ {StrPrint("%p", cp), "%2$p"}, // const char*
+ {"(nil)", "%3$p"}, // null const char *
+ {"(nil)", "%4$p"}, // null const int *
+ {StrPrint("%p", mcp), "%5$p"}, // nonconst char*
+
+ {StrPrint("%p", fp), "%6$p"}, // function pointer
+ {StrPrint("%p", vcp), "%8$p"}, // function pointer
+
+#ifndef __APPLE__
+ // Apple's printf differs here (0x0 vs. nil)
+ {StrPrint("%p", fnil), "%7$p"}, // null function pointer
+ {StrPrint("%p", vcnil), "%9$p"}, // null function pointer
+#endif
+ };
+ for (const Expectation &e : kExpect) {
+ UntypedFormatSpecImpl format(e.fmt);
+ EXPECT_EQ(e.out, FormatPack(format, absl::MakeSpan(args))) << e.fmt;
+ }
+}
+
+struct Cardinal {
+ enum Pos { k1 = 1, k2 = 2, k3 = 3 };
+ enum Neg { kM1 = -1, kM2 = -2, kM3 = -3 };
+};
+
+TEST_F(FormatConvertTest, Enum) {
+ const Cardinal::Pos k3 = Cardinal::k3;
+ const Cardinal::Neg km3 = Cardinal::kM3;
+ const FormatArgImpl args[] = {FormatArgImpl(k3), FormatArgImpl(km3)};
+ UntypedFormatSpecImpl format("%1$d");
+ UntypedFormatSpecImpl format2("%2$d");
+ EXPECT_EQ("3", FormatPack(format, absl::MakeSpan(args)));
+ EXPECT_EQ("-3", FormatPack(format2, absl::MakeSpan(args)));
+}
+
+template <typename T>
+class TypedFormatConvertTest : public FormatConvertTest { };
+
+TYPED_TEST_SUITE_P(TypedFormatConvertTest);
+
+std::vector<std::string> AllFlagCombinations() {
+ const char kFlags[] = {'-', '#', '0', '+', ' '};
+ std::vector<std::string> result;
+ for (size_t fsi = 0; fsi < (1ull << ArraySize(kFlags)); ++fsi) {
+ std::string flag_set;
+ for (size_t fi = 0; fi < ArraySize(kFlags); ++fi)
+ if (fsi & (1ull << fi))
+ flag_set += kFlags[fi];
+ result.push_back(flag_set);
+ }
+ return result;
+}
+
+TYPED_TEST_P(TypedFormatConvertTest, AllIntsWithFlags) {
+ typedef TypeParam T;
+ typedef typename std::make_unsigned<T>::type UnsignedT;
+ using remove_volatile_t = typename std::remove_volatile<T>::type;
+ const T kMin = std::numeric_limits<remove_volatile_t>::min();
+ const T kMax = std::numeric_limits<remove_volatile_t>::max();
+ const T kVals[] = {
+ remove_volatile_t(1),
+ remove_volatile_t(2),
+ remove_volatile_t(3),
+ remove_volatile_t(123),
+ remove_volatile_t(-1),
+ remove_volatile_t(-2),
+ remove_volatile_t(-3),
+ remove_volatile_t(-123),
+ remove_volatile_t(0),
+ kMax - remove_volatile_t(1),
+ kMax,
+ kMin + remove_volatile_t(1),
+ kMin,
+ };
+ const char kConvChars[] = {'d', 'i', 'u', 'o', 'x', 'X'};
+ const std::string kWid[] = {"", "4", "10"};
+ const std::string kPrec[] = {"", ".", ".0", ".4", ".10"};
+
+ const std::vector<std::string> flag_sets = AllFlagCombinations();
+
+ for (size_t vi = 0; vi < ArraySize(kVals); ++vi) {
+ const T val = kVals[vi];
+ SCOPED_TRACE(Esc(val));
+ const FormatArgImpl args[] = {FormatArgImpl(val)};
+ for (size_t ci = 0; ci < ArraySize(kConvChars); ++ci) {
+ const char conv_char = kConvChars[ci];
+ for (size_t fsi = 0; fsi < flag_sets.size(); ++fsi) {
+ const std::string &flag_set = flag_sets[fsi];
+ for (size_t wi = 0; wi < ArraySize(kWid); ++wi) {
+ const std::string &wid = kWid[wi];
+ for (size_t pi = 0; pi < ArraySize(kPrec); ++pi) {
+ const std::string &prec = kPrec[pi];
+
+ const bool is_signed_conv = (conv_char == 'd' || conv_char == 'i');
+ const bool is_unsigned_to_signed =
+ !std::is_signed<T>::value && is_signed_conv;
+ // Don't consider sign-related flags '+' and ' ' when doing
+ // unsigned to signed conversions.
+ if (is_unsigned_to_signed &&
+ flag_set.find_first_of("+ ") != std::string::npos) {
+ continue;
+ }
+
+ std::string new_fmt("%");
+ new_fmt += flag_set;
+ new_fmt += wid;
+ new_fmt += prec;
+ // old and new always agree up to here.
+ std::string old_fmt = new_fmt;
+ new_fmt += conv_char;
+ std::string old_result;
+ if (is_unsigned_to_signed) {
+ // don't expect agreement on unsigned formatted as signed,
+ // as printf can't do that conversion properly. For those
+ // cases, we do expect agreement with printf with a "%u"
+ // and the unsigned equivalent of 'val'.
+ UnsignedT uval = val;
+ old_fmt += LengthModFor(uval);
+ old_fmt += "u";
+ old_result = StrPrint(old_fmt.c_str(), uval);
+ } else {
+ old_fmt += LengthModFor(val);
+ old_fmt += conv_char;
+ old_result = StrPrint(old_fmt.c_str(), val);
+ }
+
+ SCOPED_TRACE(std::string() + " old_fmt: \"" + old_fmt +
+ "\"'"
+ " new_fmt: \"" +
+ new_fmt + "\"");
+ UntypedFormatSpecImpl format(new_fmt);
+ EXPECT_EQ(old_result, FormatPack(format, absl::MakeSpan(args)));
+ }
+ }
+ }
+ }
+ }
+}
+
+TYPED_TEST_P(TypedFormatConvertTest, Char) {
+ typedef TypeParam T;
+ using remove_volatile_t = typename std::remove_volatile<T>::type;
+ static const T kMin = std::numeric_limits<remove_volatile_t>::min();
+ static const T kMax = std::numeric_limits<remove_volatile_t>::max();
+ T kVals[] = {
+ remove_volatile_t(1), remove_volatile_t(2), remove_volatile_t(10),
+ remove_volatile_t(-1), remove_volatile_t(-2), remove_volatile_t(-10),
+ remove_volatile_t(0),
+ kMin + remove_volatile_t(1), kMin,
+ kMax - remove_volatile_t(1), kMax
+ };
+ for (const T &c : kVals) {
+ const FormatArgImpl args[] = {FormatArgImpl(c)};
+ UntypedFormatSpecImpl format("%c");
+ EXPECT_EQ(StrPrint("%c", c), FormatPack(format, absl::MakeSpan(args)));
+ }
+}
+
+REGISTER_TYPED_TEST_CASE_P(TypedFormatConvertTest, AllIntsWithFlags, Char);
+
+typedef ::testing::Types<
+ int, unsigned, volatile int,
+ short, unsigned short,
+ long, unsigned long,
+ long long, unsigned long long,
+ signed char, unsigned char, char>
+ AllIntTypes;
+INSTANTIATE_TYPED_TEST_CASE_P(TypedFormatConvertTestWithAllIntTypes,
+ TypedFormatConvertTest, AllIntTypes);
+
+TEST_F(FormatConvertTest, VectorBool) {
+ // Make sure vector<bool>'s values behave as bools.
+ std::vector<bool> v = {true, false};
+ const std::vector<bool> cv = {true, false};
+ EXPECT_EQ("1,0,1,0",
+ FormatPack(UntypedFormatSpecImpl("%d,%d,%d,%d"),
+ absl::Span<const FormatArgImpl>(
+ {FormatArgImpl(v[0]), FormatArgImpl(v[1]),
+ FormatArgImpl(cv[0]), FormatArgImpl(cv[1])})));
+}
+
+TEST_F(FormatConvertTest, Uint128) {
+ absl::uint128 v = static_cast<absl::uint128>(0x1234567890abcdef) * 1979;
+ absl::uint128 max = absl::Uint128Max();
+ const FormatArgImpl args[] = {FormatArgImpl(v), FormatArgImpl(max)};
+
+ struct Case {
+ const char* format;
+ const char* expected;
+ } cases[] = {
+ {"%1$d", "2595989796776606496405"},
+ {"%1$30d", " 2595989796776606496405"},
+ {"%1$-30d", "2595989796776606496405 "},
+ {"%1$u", "2595989796776606496405"},
+ {"%1$x", "8cba9876066020f695"},
+ {"%2$d", "340282366920938463463374607431768211455"},
+ {"%2$u", "340282366920938463463374607431768211455"},
+ {"%2$x", "ffffffffffffffffffffffffffffffff"},
+ };
+
+ for (auto c : cases) {
+ UntypedFormatSpecImpl format(c.format);
+ EXPECT_EQ(c.expected, FormatPack(format, absl::MakeSpan(args)));
+ }
+}
+
+TEST_F(FormatConvertTest, Float) {
+#ifdef _MSC_VER
+ // MSVC has a different rounding policy than us so we can't test our
+ // implementation against the native one there.
+ return;
+#endif // _MSC_VER
+
+ const char *const kFormats[] = {
+ "%", "%.3", "%8.5", "%9", "%.60", "%.30", "%03", "%+",
+ "% ", "%-10", "%#15.3", "%#.0", "%.0", "%1$*2$", "%1$.*2$"};
+
+ std::vector<double> doubles = {0.0,
+ -0.0,
+ .99999999999999,
+ 99999999999999.,
+ std::numeric_limits<double>::max(),
+ -std::numeric_limits<double>::max(),
+ std::numeric_limits<double>::min(),
+ -std::numeric_limits<double>::min(),
+ std::numeric_limits<double>::lowest(),
+ -std::numeric_limits<double>::lowest(),
+ std::numeric_limits<double>::epsilon(),
+ std::numeric_limits<double>::epsilon() + 1,
+ std::numeric_limits<double>::infinity(),
+ -std::numeric_limits<double>::infinity()};
+
+#ifndef __APPLE__
+ // Apple formats NaN differently (+nan) vs. (nan)
+ doubles.push_back(std::nan(""));
+#endif
+
+ // Some regression tests.
+ doubles.push_back(0.99999999999999989);
+
+ if (std::numeric_limits<double>::has_denorm != std::denorm_absent) {
+ doubles.push_back(std::numeric_limits<double>::denorm_min());
+ doubles.push_back(-std::numeric_limits<double>::denorm_min());
+ }
+
+ for (double base :
+ {1., 12., 123., 1234., 12345., 123456., 1234567., 12345678., 123456789.,
+ 1234567890., 12345678901., 123456789012., 1234567890123.}) {
+ for (int exp = -123; exp <= 123; ++exp) {
+ for (int sign : {1, -1}) {
+ doubles.push_back(sign * std::ldexp(base, exp));
+ }
+ }
+ }
+
+ for (const char *fmt : kFormats) {
+ for (char f : {'f', 'F', //
+ 'g', 'G', //
+ 'a', 'A', //
+ 'e', 'E'}) {
+ std::string fmt_str = std::string(fmt) + f;
+ for (double d : doubles) {
+ int i = -10;
+ FormatArgImpl args[2] = {FormatArgImpl(d), FormatArgImpl(i)};
+ UntypedFormatSpecImpl format(fmt_str);
+ // We use ASSERT_EQ here because failures are usually correlated and a
+ // bug would print way too many failed expectations causing the test to
+ // time out.
+ ASSERT_EQ(StrPrint(fmt_str.c_str(), d, i),
+ FormatPack(format, absl::MakeSpan(args)))
+ << fmt_str << " " << StrPrint("%.18g", d) << " "
+ << StrPrint("%.999f", d);
+ }
+ }
+ }
+}
+
+TEST_F(FormatConvertTest, LongDouble) {
+ const char *const kFormats[] = {"%", "%.3", "%8.5", "%9",
+ "%.60", "%+", "% ", "%-10"};
+
+ // This value is not representable in double, but it is in long double that
+ // uses the extended format.
+ // This is to verify that we are not truncating the value mistakenly through a
+ // double.
+ long double very_precise = 10000000000000000.25L;
+
+ std::vector<long double> doubles = {
+ 0.0,
+ -0.0,
+ very_precise,
+ 1 / very_precise,
+ std::numeric_limits<long double>::max(),
+ -std::numeric_limits<long double>::max(),
+ std::numeric_limits<long double>::min(),
+ -std::numeric_limits<long double>::min(),
+ std::numeric_limits<long double>::infinity(),
+ -std::numeric_limits<long double>::infinity()};
+
+ for (const char *fmt : kFormats) {
+ for (char f : {'f', 'F', //
+ 'g', 'G', //
+ 'a', 'A', //
+ 'e', 'E'}) {
+ std::string fmt_str = std::string(fmt) + 'L' + f;
+ for (auto d : doubles) {
+ FormatArgImpl arg(d);
+ UntypedFormatSpecImpl format(fmt_str);
+ // We use ASSERT_EQ here because failures are usually correlated and a
+ // bug would print way too many failed expectations causing the test to
+ // time out.
+ ASSERT_EQ(StrPrint(fmt_str.c_str(), d),
+ FormatPack(format, {&arg, 1}))
+ << fmt_str << " " << StrPrint("%.18Lg", d) << " "
+ << StrPrint("%.999Lf", d);
+ }
+ }
+ }
+}
+
+TEST_F(FormatConvertTest, IntAsFloat) {
+ const int kMin = std::numeric_limits<int>::min();
+ const int kMax = std::numeric_limits<int>::max();
+ const int ia[] = {
+ 1, 2, 3, 123,
+ -1, -2, -3, -123,
+ 0, kMax - 1, kMax, kMin + 1, kMin };
+ for (const int fx : ia) {
+ SCOPED_TRACE(fx);
+ const FormatArgImpl args[] = {FormatArgImpl(fx)};
+ struct Expectation {
+ int line;
+ std::string out;
+ const char *fmt;
+ };
+ const double dx = static_cast<double>(fx);
+ const Expectation kExpect[] = {
+ { __LINE__, StrPrint("%f", dx), "%f" },
+ { __LINE__, StrPrint("%12f", dx), "%12f" },
+ { __LINE__, StrPrint("%.12f", dx), "%.12f" },
+ { __LINE__, StrPrint("%12a", dx), "%12a" },
+ { __LINE__, StrPrint("%.12a", dx), "%.12a" },
+ };
+ for (const Expectation &e : kExpect) {
+ SCOPED_TRACE(e.line);
+ SCOPED_TRACE(e.fmt);
+ UntypedFormatSpecImpl format(e.fmt);
+ EXPECT_EQ(e.out, FormatPack(format, absl::MakeSpan(args)));
+ }
+ }
+}
+
+template <typename T>
+bool FormatFails(const char* test_format, T value) {
+ std::string format_string = std::string("<<") + test_format + ">>";
+ UntypedFormatSpecImpl format(format_string);
+
+ int one = 1;
+ const FormatArgImpl args[] = {FormatArgImpl(value), FormatArgImpl(one)};
+ EXPECT_EQ(FormatPack(format, absl::MakeSpan(args)), "")
+ << "format=" << test_format << " value=" << value;
+ return FormatPack(format, absl::MakeSpan(args)).empty();
+}
+
+TEST_F(FormatConvertTest, ExpectedFailures) {
+ // Int input
+ EXPECT_TRUE(FormatFails("%p", 1));
+ EXPECT_TRUE(FormatFails("%s", 1));
+ EXPECT_TRUE(FormatFails("%n", 1));
+
+ // Double input
+ EXPECT_TRUE(FormatFails("%p", 1.));
+ EXPECT_TRUE(FormatFails("%s", 1.));
+ EXPECT_TRUE(FormatFails("%n", 1.));
+ EXPECT_TRUE(FormatFails("%c", 1.));
+ EXPECT_TRUE(FormatFails("%d", 1.));
+ EXPECT_TRUE(FormatFails("%x", 1.));
+ EXPECT_TRUE(FormatFails("%*d", 1.));
+
+ // String input
+ EXPECT_TRUE(FormatFails("%n", ""));
+ EXPECT_TRUE(FormatFails("%c", ""));
+ EXPECT_TRUE(FormatFails("%d", ""));
+ EXPECT_TRUE(FormatFails("%x", ""));
+ EXPECT_TRUE(FormatFails("%f", ""));
+ EXPECT_TRUE(FormatFails("%*d", ""));
+}
+
+} // namespace
+} // namespace str_format_internal
+} // namespace absl
diff --git a/absl/strings/internal/str_format/extension.cc b/absl/strings/internal/str_format/extension.cc
new file mode 100644
index 0000000..d7f5815
--- /dev/null
+++ b/absl/strings/internal/str_format/extension.cc
@@ -0,0 +1,84 @@
+//
+// Copyright 2017 The Abseil Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include "absl/strings/internal/str_format/extension.h"
+
+#include <errno.h>
+#include <algorithm>
+#include <string>
+
+namespace absl {
+namespace str_format_internal {
+namespace {
+// clang-format off
+#define ABSL_LENGTH_MODS_EXPAND_ \
+ X_VAL(h) X_SEP \
+ X_VAL(hh) X_SEP \
+ X_VAL(l) X_SEP \
+ X_VAL(ll) X_SEP \
+ X_VAL(L) X_SEP \
+ X_VAL(j) X_SEP \
+ X_VAL(z) X_SEP \
+ X_VAL(t) X_SEP \
+ X_VAL(q)
+// clang-format on
+} // namespace
+
+const LengthMod::Spec LengthMod::kSpecs[] = {
+#define X_VAL(id) { LengthMod::id, #id, strlen(#id) }
+#define X_SEP ,
+ ABSL_LENGTH_MODS_EXPAND_, {LengthMod::none, "", 0}
+#undef X_VAL
+#undef X_SEP
+};
+
+const ConversionChar::Spec ConversionChar::kSpecs[] = {
+#define X_VAL(id) { ConversionChar::id, #id[0] }
+#define X_SEP ,
+ ABSL_CONVERSION_CHARS_EXPAND_(X_VAL, X_SEP),
+ {ConversionChar::none, '\0'},
+#undef X_VAL
+#undef X_SEP
+};
+
+std::string Flags::ToString() const {
+ std::string s;
+ s.append(left ? "-" : "");
+ s.append(show_pos ? "+" : "");
+ s.append(sign_col ? " " : "");
+ s.append(alt ? "#" : "");
+ s.append(zero ? "0" : "");
+ return s;
+}
+
+const size_t LengthMod::kNumValues;
+
+const size_t ConversionChar::kNumValues;
+
+bool FormatSinkImpl::PutPaddedString(string_view v, int w, int p, bool l) {
+ size_t space_remaining = 0;
+ if (w >= 0) space_remaining = w;
+ size_t n = v.size();
+ if (p >= 0) n = std::min(n, static_cast<size_t>(p));
+ string_view shown(v.data(), n);
+ space_remaining = Excess(shown.size(), space_remaining);
+ if (!l) Append(space_remaining, ' ');
+ Append(shown);
+ if (l) Append(space_remaining, ' ');
+ return true;
+}
+
+} // namespace str_format_internal
+} // namespace absl
diff --git a/absl/strings/internal/str_format/extension.h b/absl/strings/internal/str_format/extension.h
new file mode 100644
index 0000000..eb81f8a
--- /dev/null
+++ b/absl/strings/internal/str_format/extension.h
@@ -0,0 +1,411 @@
+//
+// Copyright 2017 The Abseil Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+#ifndef ABSL_STRINGS_INTERNAL_STR_FORMAT_EXTENSION_H_
+#define ABSL_STRINGS_INTERNAL_STR_FORMAT_EXTENSION_H_
+
+#include <limits.h>
+#include <cstddef>
+#include <cstring>
+#include <ostream>
+
+#include "absl/base/port.h"
+#include "absl/strings/internal/str_format/output.h"
+#include "absl/strings/string_view.h"
+
+class Cord;
+
+namespace absl {
+
+namespace str_format_internal {
+
+class FormatRawSinkImpl {
+ public:
+ // Implicitly convert from any type that provides the hook function as
+ // described above.
+ template <typename T, decltype(str_format_internal::InvokeFlush(
+ std::declval<T*>(), string_view()))* = nullptr>
+ FormatRawSinkImpl(T* raw) // NOLINT
+ : sink_(raw), write_(&FormatRawSinkImpl::Flush<T>) {}
+
+ void Write(string_view s) { write_(sink_, s); }
+
+ template <typename T>
+ static FormatRawSinkImpl Extract(T s) {
+ return s.sink_;
+ }
+
+ private:
+ template <typename T>
+ static void Flush(void* r, string_view s) {
+ str_format_internal::InvokeFlush(static_cast<T*>(r), s);
+ }
+
+ void* sink_;
+ void (*write_)(void*, string_view);
+};
+
+// An abstraction to which conversions write their string data.
+class FormatSinkImpl {
+ public:
+ explicit FormatSinkImpl(FormatRawSinkImpl raw) : raw_(raw) {}
+
+ ~FormatSinkImpl() { Flush(); }
+
+ void Flush() {
+ raw_.Write(string_view(buf_, pos_ - buf_));
+ pos_ = buf_;
+ }
+
+ void Append(size_t n, char c) {
+ if (n == 0) return;
+ size_ += n;
+ auto raw_append = [&](size_t count) {
+ memset(pos_, c, count);
+ pos_ += count;
+ };
+ while (n > Avail()) {
+ n -= Avail();
+ if (Avail() > 0) {
+ raw_append(Avail());
+ }
+ Flush();
+ }
+ raw_append(n);
+ }
+
+ void Append(string_view v) {
+ size_t n = v.size();
+ if (n == 0) return;
+ size_ += n;
+ if (n >= Avail()) {
+ Flush();
+ raw_.Write(v);
+ return;
+ }
+ memcpy(pos_, v.data(), n);
+ pos_ += n;
+ }
+
+ size_t size() const { return size_; }
+
+ // Put 'v' to 'sink' with specified width, precision, and left flag.
+ bool PutPaddedString(string_view v, int w, int p, bool l);
+
+ template <typename T>
+ T Wrap() {
+ return T(this);
+ }
+
+ template <typename T>
+ static FormatSinkImpl* Extract(T* s) {
+ return s->sink_;
+ }
+
+ private:
+ size_t Avail() const { return buf_ + sizeof(buf_) - pos_; }
+
+ FormatRawSinkImpl raw_;
+ size_t size_ = 0;
+ char* pos_ = buf_;
+ char buf_[1024];
+};
+
+struct Flags {
+ bool basic : 1; // fastest conversion: no flags, width, or precision
+ bool left : 1; // "-"
+ bool show_pos : 1; // "+"
+ bool sign_col : 1; // " "
+ bool alt : 1; // "#"
+ bool zero : 1; // "0"
+ std::string ToString() const;
+ friend std::ostream& operator<<(std::ostream& os, const Flags& v) {
+ return os << v.ToString();
+ }
+};
+
+struct LengthMod {
+ public:
+ enum Id : uint8_t {
+ h, hh, l, ll, L, j, z, t, q, none
+ };
+ static const size_t kNumValues = none + 1;
+
+ LengthMod() : id_(none) {}
+
+ // Index into the opaque array of LengthMod enums.
+ // Requires: i < kNumValues
+ static LengthMod FromIndex(size_t i) {
+ return LengthMod(kSpecs[i].value);
+ }
+
+ static LengthMod FromId(Id id) { return LengthMod(id); }
+
+ // The length modifier std::string associated with a specified LengthMod.
+ string_view name() const {
+ const Spec& spec = kSpecs[id_];
+ return {spec.name, spec.name_length};
+ }
+
+ Id id() const { return id_; }
+
+ friend bool operator==(const LengthMod& a, const LengthMod& b) {
+ return a.id() == b.id();
+ }
+ friend bool operator!=(const LengthMod& a, const LengthMod& b) {
+ return !(a == b);
+ }
+ friend std::ostream& operator<<(std::ostream& os, const LengthMod& v) {
+ return os << v.name();
+ }
+
+ private:
+ struct Spec {
+ Id value;
+ const char *name;
+ size_t name_length;
+ };
+ static const Spec kSpecs[];
+
+ explicit LengthMod(Id id) : id_(id) {}
+
+ Id id_;
+};
+
+// clang-format off
+#define ABSL_CONVERSION_CHARS_EXPAND_(X_VAL, X_SEP) \
+ /* text */ \
+ X_VAL(c) X_SEP X_VAL(C) X_SEP X_VAL(s) X_SEP X_VAL(S) X_SEP \
+ /* ints */ \
+ X_VAL(d) X_SEP X_VAL(i) X_SEP X_VAL(o) X_SEP \
+ X_VAL(u) X_SEP X_VAL(x) X_SEP X_VAL(X) X_SEP \
+ /* floats */ \
+ X_VAL(f) X_SEP X_VAL(F) X_SEP X_VAL(e) X_SEP X_VAL(E) X_SEP \
+ X_VAL(g) X_SEP X_VAL(G) X_SEP X_VAL(a) X_SEP X_VAL(A) X_SEP \
+ /* misc */ \
+ X_VAL(n) X_SEP X_VAL(p)
+// clang-format on
+
+struct ConversionChar {
+ public:
+ enum Id : uint8_t {
+ c, C, s, S, // text
+ d, i, o, u, x, X, // int
+ f, F, e, E, g, G, a, A, // float
+ n, p, // misc
+ none
+ };
+ static const size_t kNumValues = none + 1;
+
+ ConversionChar() : id_(none) {}
+
+ public:
+ // Index into the opaque array of ConversionChar enums.
+ // Requires: i < kNumValues
+ static ConversionChar FromIndex(size_t i) {
+ return ConversionChar(kSpecs[i].value);
+ }
+
+ static ConversionChar FromChar(char c) {
+ ConversionChar::Id out_id = ConversionChar::none;
+ switch (c) {
+#define X_VAL(id) \
+ case #id[0]: \
+ out_id = ConversionChar::id; \
+ break;
+ ABSL_CONVERSION_CHARS_EXPAND_(X_VAL, )
+#undef X_VAL
+ default:
+ break;
+ }
+ return ConversionChar(out_id);
+ }
+
+ static ConversionChar FromId(Id id) { return ConversionChar(id); }
+ Id id() const { return id_; }
+
+ int radix() const {
+ switch (id()) {
+ case x: case X: case a: case A: case p: return 16;
+ case o: return 8;
+ default: return 10;
+ }
+ }
+
+ bool upper() const {
+ switch (id()) {
+ case X: case F: case E: case G: case A: return true;
+ default: return false;
+ }
+ }
+
+ bool is_signed() const {
+ switch (id()) {
+ case d: case i: return true;
+ default: return false;
+ }
+ }
+
+ bool is_integral() const {
+ switch (id()) {
+ case d: case i: case u: case o: case x: case X:
+ return true;
+ default: return false;
+ }
+ }
+
+ bool is_float() const {
+ switch (id()) {
+ case a: case e: case f: case g: case A: case E: case F: case G:
+ return true;
+ default: return false;
+ }
+ }
+
+ bool IsValid() const { return id() != none; }
+
+ // The associated char.
+ char Char() const { return kSpecs[id_].name; }
+
+ friend bool operator==(const ConversionChar& a, const ConversionChar& b) {
+ return a.id() == b.id();
+ }
+ friend bool operator!=(const ConversionChar& a, const ConversionChar& b) {
+ return !(a == b);
+ }
+ friend std::ostream& operator<<(std::ostream& os, const ConversionChar& v) {
+ char c = v.Char();
+ if (!c) c = '?';
+ return os << c;
+ }
+
+ private:
+ struct Spec {
+ Id value;
+ char name;
+ };
+ static const Spec kSpecs[];
+
+ explicit ConversionChar(Id id) : id_(id) {}
+
+ Id id_;
+};
+
+class ConversionSpec {
+ public:
+ Flags flags() const { return flags_; }
+ LengthMod length_mod() const { return length_mod_; }
+ ConversionChar conv() const {
+ // Keep this field first in the struct . It generates better code when
+ // accessing it when ConversionSpec is passed by value in registers.
+ static_assert(offsetof(ConversionSpec, conv_) == 0, "");
+ return conv_;
+ }
+
+ // Returns the specified width. If width is unspecfied, it returns a negative
+ // value.
+ int width() const { return width_; }
+ // Returns the specified precision. If precision is unspecfied, it returns a
+ // negative value.
+ int precision() const { return precision_; }
+
+ void set_flags(Flags f) { flags_ = f; }
+ void set_length_mod(LengthMod lm) { length_mod_ = lm; }
+ void set_conv(ConversionChar c) { conv_ = c; }
+ void set_width(int w) { width_ = w; }
+ void set_precision(int p) { precision_ = p; }
+ void set_left(bool b) { flags_.left = b; }
+
+ private:
+ ConversionChar conv_;
+ Flags flags_;
+ LengthMod length_mod_;
+ int width_;
+ int precision_;
+};
+
+constexpr uint64_t ConversionCharToConvValue(char conv) {
+ return
+#define CONV_SET_CASE(c) \
+ conv == #c[0] ? (uint64_t{1} << (1 + ConversionChar::Id::c)):
+ ABSL_CONVERSION_CHARS_EXPAND_(CONV_SET_CASE, )
+#undef CONV_SET_CASE
+ conv == '*'
+ ? 1
+ : 0;
+}
+
+enum class Conv : uint64_t {
+#define CONV_SET_CASE(c) c = ConversionCharToConvValue(#c[0]),
+ ABSL_CONVERSION_CHARS_EXPAND_(CONV_SET_CASE, )
+#undef CONV_SET_CASE
+
+ // Used for width/precision '*' specification.
+ star = ConversionCharToConvValue('*'),
+
+ // Some predefined values:
+ integral = d | i | u | o | x | X,
+ floating = a | e | f | g | A | E | F | G,
+ numeric = integral | floating,
+ string = s,
+ pointer = p
+};
+
+// Type safe OR operator.
+// We need this for two reasons:
+// 1. operator| on enums makes them decay to integers and the result is an
+// integer. We need the result to stay as an enum.
+// 2. We use "enum class" which would not work even if we accepted the decay.
+constexpr Conv operator|(Conv a, Conv b) {
+ return Conv(static_cast<uint64_t>(a) | static_cast<uint64_t>(b));
+}
+
+// Get a conversion with a single character in it.
+constexpr Conv ConversionCharToConv(char c) {
+ return Conv(ConversionCharToConvValue(c));
+}
+
+// Checks whether `c` exists in `set`.
+constexpr bool Contains(Conv set, char c) {
+ return (static_cast<uint64_t>(set) & ConversionCharToConvValue(c)) != 0;
+}
+
+// Checks whether all the characters in `c` are contained in `set`
+constexpr bool Contains(Conv set, Conv c) {
+ return (static_cast<uint64_t>(set) & static_cast<uint64_t>(c)) ==
+ static_cast<uint64_t>(c);
+}
+
+// Return type of the AbslFormatConvert() functions.
+// The Conv template parameter is used to inform the framework of what
+// conversion characters are supported by that AbslFormatConvert routine.
+template <Conv C>
+struct ConvertResult {
+ static constexpr Conv kConv = C;
+ bool value;
+};
+template <Conv C>
+constexpr Conv ConvertResult<C>::kConv;
+
+// Return capacity - used, clipped to a minimum of 0.
+inline size_t Excess(size_t used, size_t capacity) {
+ return used < capacity ? capacity - used : 0;
+}
+
+} // namespace str_format_internal
+
+} // namespace absl
+
+#endif // ABSL_STRINGS_INTERNAL_STR_FORMAT_EXTENSION_H_
diff --git a/absl/strings/internal/str_format/extension_test.cc b/absl/strings/internal/str_format/extension_test.cc
new file mode 100644
index 0000000..4e23fef
--- /dev/null
+++ b/absl/strings/internal/str_format/extension_test.cc
@@ -0,0 +1,66 @@
+//
+// Copyright 2017 The Abseil Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+
+#include "absl/strings/internal/str_format/extension.h"
+
+#include <random>
+#include <string>
+
+#include "absl/strings/str_format.h"
+
+#include "gtest/gtest.h"
+
+namespace {
+
+std::string MakeRandomString(size_t len) {
+ std::random_device rd;
+ std::mt19937 gen(rd());
+ std::uniform_int_distribution<> dis('a', 'z');
+ std::string s(len, '0');
+ for (char& c : s) {
+ c = dis(gen);
+ }
+ return s;
+}
+
+TEST(FormatExtensionTest, SinkAppendSubstring) {
+ for (size_t chunk_size : {1, 10, 100, 1000, 10000}) {
+ std::string expected, actual;
+ absl::str_format_internal::FormatSinkImpl sink(&actual);
+ for (size_t chunks = 0; chunks < 10; ++chunks) {
+ std::string rand = MakeRandomString(chunk_size);
+ expected += rand;
+ sink.Append(rand);
+ }
+ sink.Flush();
+ EXPECT_EQ(actual, expected);
+ }
+}
+
+TEST(FormatExtensionTest, SinkAppendChars) {
+ for (size_t chunk_size : {1, 10, 100, 1000, 10000}) {
+ std::string expected, actual;
+ absl::str_format_internal::FormatSinkImpl sink(&actual);
+ for (size_t chunks = 0; chunks < 10; ++chunks) {
+ std::string rand = MakeRandomString(1);
+ expected.append(chunk_size, rand[0]);
+ sink.Append(chunk_size, rand[0]);
+ }
+ sink.Flush();
+ EXPECT_EQ(actual, expected);
+ }
+}
+} // namespace
diff --git a/absl/strings/internal/str_format/float_conversion.cc b/absl/strings/internal/str_format/float_conversion.cc
new file mode 100644
index 0000000..9236acd
--- /dev/null
+++ b/absl/strings/internal/str_format/float_conversion.cc
@@ -0,0 +1,485 @@
+#include "absl/strings/internal/str_format/float_conversion.h"
+
+#include <string.h>
+#include <algorithm>
+#include <cassert>
+#include <cmath>
+#include <string>
+
+#include "absl/base/config.h"
+
+namespace absl {
+namespace str_format_internal {
+
+namespace {
+
+char *CopyStringTo(string_view v, char *out) {
+ std::memcpy(out, v.data(), v.size());
+ return out + v.size();
+}
+
+template <typename Float>
+bool FallbackToSnprintf(const Float v, const ConversionSpec &conv,
+ FormatSinkImpl *sink) {
+ int w = conv.width() >= 0 ? conv.width() : 0;
+ int p = conv.precision() >= 0 ? conv.precision() : -1;
+ char fmt[32];
+ {
+ char *fp = fmt;
+ *fp++ = '%';
+ fp = CopyStringTo(conv.flags().ToString(), fp);
+ fp = CopyStringTo("*.*", fp);
+ if (std::is_same<long double, Float>()) {
+ *fp++ = 'L';
+ }
+ *fp++ = conv.conv().Char();
+ *fp = 0;
+ assert(fp < fmt + sizeof(fmt));
+ }
+ std::string space(512, '\0');
+ string_view result;
+ while (true) {
+ int n = snprintf(&space[0], space.size(), fmt, w, p, v);
+ if (n < 0) return false;
+ if (static_cast<size_t>(n) < space.size()) {
+ result = string_view(space.data(), n);
+ break;
+ }
+ space.resize(n + 1);
+ }
+ sink->Append(result);
+ return true;
+}
+
+// 128-bits in decimal: ceil(128*log(2)/log(10))
+// or std::numeric_limits<__uint128_t>::digits10
+constexpr int kMaxFixedPrecision = 39;
+
+constexpr int kBufferLength = /*sign*/ 1 +
+ /*integer*/ kMaxFixedPrecision +
+ /*point*/ 1 +
+ /*fraction*/ kMaxFixedPrecision +
+ /*exponent e+123*/ 5;
+
+struct Buffer {
+ void push_front(char c) {
+ assert(begin > data);
+ *--begin = c;
+ }
+ void push_back(char c) {
+ assert(end < data + sizeof(data));
+ *end++ = c;
+ }
+ void pop_back() {
+ assert(begin < end);
+ --end;
+ }
+
+ char &back() {
+ assert(begin < end);
+ return end[-1];
+ }
+
+ char last_digit() const { return end[-1] == '.' ? end[-2] : end[-1]; }
+
+ int size() const { return static_cast<int>(end - begin); }
+
+ char data[kBufferLength];
+ char *begin;
+ char *end;
+};
+
+enum class FormatStyle { Fixed, Precision };
+
+// If the value is Inf or Nan, print it and return true.
+// Otherwise, return false.
+template <typename Float>
+bool ConvertNonNumericFloats(char sign_char, Float v,
+ const ConversionSpec &conv, FormatSinkImpl *sink) {
+ char text[4], *ptr = text;
+ if (sign_char) *ptr++ = sign_char;
+ if (std::isnan(v)) {
+ ptr = std::copy_n(conv.conv().upper() ? "NAN" : "nan", 3, ptr);
+ } else if (std::isinf(v)) {
+ ptr = std::copy_n(conv.conv().upper() ? "INF" : "inf", 3, ptr);
+ } else {
+ return false;
+ }
+
+ return sink->PutPaddedString(string_view(text, ptr - text), conv.width(), -1,
+ conv.flags().left);
+}
+
+// Round up the last digit of the value.
+// It will carry over and potentially overflow. 'exp' will be adjusted in that
+// case.
+template <FormatStyle mode>
+void RoundUp(Buffer *buffer, int *exp) {
+ char *p = &buffer->back();
+ while (p >= buffer->begin && (*p == '9' || *p == '.')) {
+ if (*p == '9') *p = '0';
+ --p;
+ }
+
+ if (p < buffer->begin) {
+ *p = '1';
+ buffer->begin = p;
+ if (mode == FormatStyle::Precision) {
+ std::swap(p[1], p[2]); // move the .
+ ++*exp;
+ buffer->pop_back();
+ }
+ } else {
+ ++*p;
+ }
+}
+
+void PrintExponent(int exp, char e, Buffer *out) {
+ out->push_back(e);
+ if (exp < 0) {
+ out->push_back('-');
+ exp = -exp;
+ } else {
+ out->push_back('+');
+ }
+ // Exponent digits.
+ if (exp > 99) {
+ out->push_back(exp / 100 + '0');
+ out->push_back(exp / 10 % 10 + '0');
+ out->push_back(exp % 10 + '0');
+ } else {
+ out->push_back(exp / 10 + '0');
+ out->push_back(exp % 10 + '0');
+ }
+}
+
+template <typename Float, typename Int>
+constexpr bool CanFitMantissa() {
+ return
+#if defined(__clang__) && !defined(__SSE3__)
+ // Workaround for clang bug: https://bugs.llvm.org/show_bug.cgi?id=38289
+ // Casting from long double to uint64_t is miscompiled and drops bits.
+ (!std::is_same<Float, long double>::value ||
+ !std::is_same<Int, uint64_t>::value) &&
+#endif
+ std::numeric_limits<Float>::digits <= std::numeric_limits<Int>::digits;
+}
+
+template <typename Float>
+struct Decomposed {
+ Float mantissa;
+ int exponent;
+};
+
+// Decompose the double into an integer mantissa and an exponent.
+template <typename Float>
+Decomposed<Float> Decompose(Float v) {
+ int exp;
+ Float m = std::frexp(v, &exp);
+ m = std::ldexp(m, std::numeric_limits<Float>::digits);
+ exp -= std::numeric_limits<Float>::digits;
+ return {m, exp};
+}
+
+// Print 'digits' as decimal.
+// In Fixed mode, we add a '.' at the end.
+// In Precision mode, we add a '.' after the first digit.
+template <FormatStyle mode, typename Int>
+int PrintIntegralDigits(Int digits, Buffer *out) {
+ int printed = 0;
+ if (digits) {
+ for (; digits; digits /= 10) out->push_front(digits % 10 + '0');
+ printed = out->size();
+ if (mode == FormatStyle::Precision) {
+ out->push_front(*out->begin);
+ out->begin[1] = '.';
+ } else {
+ out->push_back('.');
+ }
+ } else if (mode == FormatStyle::Fixed) {
+ out->push_front('0');
+ out->push_back('.');
+ printed = 1;
+ }
+ return printed;
+}
+
+// Back out 'extra_digits' digits and round up if necessary.
+bool RemoveExtraPrecision(int extra_digits, bool has_leftover_value,
+ Buffer *out, int *exp_out) {
+ if (extra_digits <= 0) return false;
+
+ // Back out the extra digits
+ out->end -= extra_digits;
+
+ bool needs_to_round_up = [&] {
+ // We look at the digit just past the end.
+ // There must be 'extra_digits' extra valid digits after end.
+ if (*out->end > '5') return true;
+ if (*out->end < '5') return false;
+ if (has_leftover_value || std::any_of(out->end + 1, out->end + extra_digits,
+ [](char c) { return c != '0'; }))
+ return true;
+
+ // Ends in ...50*, round to even.
+ return out->last_digit() % 2 == 1;
+ }();
+
+ if (needs_to_round_up) {
+ RoundUp<FormatStyle::Precision>(out, exp_out);
+ }
+ return true;
+}
+
+// Print the value into the buffer.
+// This will not include the exponent, which will be returned in 'exp_out' for
+// Precision mode.
+template <typename Int, typename Float, FormatStyle mode>
+bool FloatToBufferImpl(Int int_mantissa, int exp, int precision, Buffer *out,
+ int *exp_out) {
+ assert((CanFitMantissa<Float, Int>()));
+
+ const int int_bits = std::numeric_limits<Int>::digits;
+
+ // In precision mode, we start printing one char to the right because it will
+ // also include the '.'
+ // In fixed mode we put the dot afterwards on the right.
+ out->begin = out->end =
+ out->data + 1 + kMaxFixedPrecision + (mode == FormatStyle::Precision);
+
+ if (exp >= 0) {
+ if (std::numeric_limits<Float>::digits + exp > int_bits) {
+ // The value will overflow the Int
+ return false;
+ }
+ int digits_printed = PrintIntegralDigits<mode>(int_mantissa << exp, out);
+ int digits_to_zero_pad = precision;
+ if (mode == FormatStyle::Precision) {
+ *exp_out = digits_printed - 1;
+ digits_to_zero_pad -= digits_printed - 1;
+ if (RemoveExtraPrecision(-digits_to_zero_pad, false, out, exp_out)) {
+ return true;
+ }
+ }
+ for (; digits_to_zero_pad-- > 0;) out->push_back('0');
+ return true;
+ }
+
+ exp = -exp;
+ // We need at least 4 empty bits for the next decimal digit.
+ // We will multiply by 10.
+ if (exp > int_bits - 4) return false;
+
+ const Int mask = (Int{1} << exp) - 1;
+
+ // Print the integral part first.
+ int digits_printed = PrintIntegralDigits<mode>(int_mantissa >> exp, out);
+ int_mantissa &= mask;
+
+ int fractional_count = precision;
+ if (mode == FormatStyle::Precision) {
+ if (digits_printed == 0) {
+ // Find the first non-zero digit, when in Precision mode.
+ *exp_out = 0;
+ if (int_mantissa) {
+ while (int_mantissa <= mask) {
+ int_mantissa *= 10;
+ --*exp_out;
+ }
+ }
+ out->push_front(static_cast<char>(int_mantissa >> exp) + '0');
+ out->push_back('.');
+ int_mantissa &= mask;
+ } else {
+ // We already have a digit, and a '.'
+ *exp_out = digits_printed - 1;
+ fractional_count -= *exp_out;
+ if (RemoveExtraPrecision(-fractional_count, int_mantissa != 0, out,
+ exp_out)) {
+ // If we had enough digits, return right away.
+ // The code below will try to round again otherwise.
+ return true;
+ }
+ }
+ }
+
+ auto get_next_digit = [&] {
+ int_mantissa *= 10;
+ int digit = static_cast<int>(int_mantissa >> exp);
+ int_mantissa &= mask;
+ return digit;
+ };
+
+ // Print fractional_count more digits, if available.
+ for (; fractional_count > 0; --fractional_count) {
+ out->push_back(get_next_digit() + '0');
+ }
+
+ int next_digit = get_next_digit();
+ if (next_digit > 5 ||
+ (next_digit == 5 && (int_mantissa || out->last_digit() % 2 == 1))) {
+ RoundUp<mode>(out, exp_out);
+ }
+
+ return true;
+}
+
+template <FormatStyle mode, typename Float>
+bool FloatToBuffer(Decomposed<Float> decomposed, int precision, Buffer *out,
+ int *exp) {
+ if (precision > kMaxFixedPrecision) return false;
+
+ // Try with uint64_t.
+ if (CanFitMantissa<Float, std::uint64_t>() &&
+ FloatToBufferImpl<std::uint64_t, Float, mode>(
+ static_cast<std::uint64_t>(decomposed.mantissa),
+ static_cast<std::uint64_t>(decomposed.exponent), precision, out, exp))
+ return true;
+
+#if defined(ABSL_HAVE_INTRINSIC_INT128)
+ // If that is not enough, try with __uint128_t.
+ return CanFitMantissa<Float, __uint128_t>() &&
+ FloatToBufferImpl<__uint128_t, Float, mode>(
+ static_cast<__uint128_t>(decomposed.mantissa),
+ static_cast<__uint128_t>(decomposed.exponent), precision, out,
+ exp);
+#endif
+ return false;
+}
+
+void WriteBufferToSink(char sign_char, string_view str,
+ const ConversionSpec &conv, FormatSinkImpl *sink) {
+ int left_spaces = 0, zeros = 0, right_spaces = 0;
+ int missing_chars =
+ conv.width() >= 0 ? std::max(conv.width() - static_cast<int>(str.size()) -
+ static_cast<int>(sign_char != 0),
+ 0)
+ : 0;
+ if (conv.flags().left) {
+ right_spaces = missing_chars;
+ } else if (conv.flags().zero) {
+ zeros = missing_chars;
+ } else {
+ left_spaces = missing_chars;
+ }
+
+ sink->Append(left_spaces, ' ');
+ if (sign_char) sink->Append(1, sign_char);
+ sink->Append(zeros, '0');
+ sink->Append(str);
+ sink->Append(right_spaces, ' ');
+}
+
+template <typename Float>
+bool FloatToSink(const Float v, const ConversionSpec &conv,
+ FormatSinkImpl *sink) {
+ // Print the sign or the sign column.
+ Float abs_v = v;
+ char sign_char = 0;
+ if (std::signbit(abs_v)) {
+ sign_char = '-';
+ abs_v = -abs_v;
+ } else if (conv.flags().show_pos) {
+ sign_char = '+';
+ } else if (conv.flags().sign_col) {
+ sign_char = ' ';
+ }
+
+ // Print nan/inf.
+ if (ConvertNonNumericFloats(sign_char, abs_v, conv, sink)) {
+ return true;
+ }
+
+ int precision = conv.precision() < 0 ? 6 : conv.precision();
+
+ int exp = 0;
+
+ auto decomposed = Decompose(abs_v);
+
+ Buffer buffer;
+
+ switch (conv.conv().id()) {
+ case ConversionChar::f:
+ case ConversionChar::F:
+ if (!FloatToBuffer<FormatStyle::Fixed>(decomposed, precision, &buffer,
+ nullptr)) {
+ return FallbackToSnprintf(v, conv, sink);
+ }
+ if (!conv.flags().alt && buffer.back() == '.') buffer.pop_back();
+ break;
+
+ case ConversionChar::e:
+ case ConversionChar::E:
+ if (!FloatToBuffer<FormatStyle::Precision>(decomposed, precision, &buffer,
+ &exp)) {
+ return FallbackToSnprintf(v, conv, sink);
+ }
+ if (!conv.flags().alt && buffer.back() == '.') buffer.pop_back();
+ PrintExponent(exp, conv.conv().upper() ? 'E' : 'e', &buffer);
+ break;
+
+ case ConversionChar::g:
+ case ConversionChar::G:
+ precision = std::max(0, precision - 1);
+ if (!FloatToBuffer<FormatStyle::Precision>(decomposed, precision, &buffer,
+ &exp)) {
+ return FallbackToSnprintf(v, conv, sink);
+ }
+ if (precision + 1 > exp && exp >= -4) {
+ if (exp < 0) {
+ // Have 1.23456, needs 0.00123456
+ // Move the first digit
+ buffer.begin[1] = *buffer.begin;
+ // Add some zeros
+ for (; exp < -1; ++exp) *buffer.begin-- = '0';
+ *buffer.begin-- = '.';
+ *buffer.begin = '0';
+ } else if (exp > 0) {
+ // Have 1.23456, needs 1234.56
+ // Move the '.' exp positions to the right.
+ std::rotate(buffer.begin + 1, buffer.begin + 2,
+ buffer.begin + exp + 2);
+ }
+ exp = 0;
+ }
+ if (!conv.flags().alt) {
+ while (buffer.back() == '0') buffer.pop_back();
+ if (buffer.back() == '.') buffer.pop_back();
+ }
+ if (exp) PrintExponent(exp, conv.conv().upper() ? 'E' : 'e', &buffer);
+ break;
+
+ case ConversionChar::a:
+ case ConversionChar::A:
+ return FallbackToSnprintf(v, conv, sink);
+
+ default:
+ return false;
+ }
+
+ WriteBufferToSink(sign_char,
+ string_view(buffer.begin, buffer.end - buffer.begin), conv,
+ sink);
+
+ return true;
+}
+
+} // namespace
+
+bool ConvertFloatImpl(long double v, const ConversionSpec &conv,
+ FormatSinkImpl *sink) {
+ return FloatToSink(v, conv, sink);
+}
+
+bool ConvertFloatImpl(float v, const ConversionSpec &conv,
+ FormatSinkImpl *sink) {
+ return FloatToSink(v, conv, sink);
+}
+
+bool ConvertFloatImpl(double v, const ConversionSpec &conv,
+ FormatSinkImpl *sink) {
+ return FloatToSink(v, conv, sink);
+}
+
+} // namespace str_format_internal
+} // namespace absl
diff --git a/absl/strings/internal/str_format/float_conversion.h b/absl/strings/internal/str_format/float_conversion.h
new file mode 100644
index 0000000..8ba5566
--- /dev/null
+++ b/absl/strings/internal/str_format/float_conversion.h
@@ -0,0 +1,21 @@
+#ifndef ABSL_STRINGS_INTERNAL_STR_FORMAT_FLOAT_CONVERSION_H_
+#define ABSL_STRINGS_INTERNAL_STR_FORMAT_FLOAT_CONVERSION_H_
+
+#include "absl/strings/internal/str_format/extension.h"
+
+namespace absl {
+namespace str_format_internal {
+
+bool ConvertFloatImpl(float v, const ConversionSpec &conv,
+ FormatSinkImpl *sink);
+
+bool ConvertFloatImpl(double v, const ConversionSpec &conv,
+ FormatSinkImpl *sink);
+
+bool ConvertFloatImpl(long double v, const ConversionSpec &conv,
+ FormatSinkImpl *sink);
+
+} // namespace str_format_internal
+} // namespace absl
+
+#endif // ABSL_STRINGS_INTERNAL_STR_FORMAT_FLOAT_CONVERSION_H_
diff --git a/absl/strings/internal/str_format/output.cc b/absl/strings/internal/str_format/output.cc
new file mode 100644
index 0000000..38987b6
--- /dev/null
+++ b/absl/strings/internal/str_format/output.cc
@@ -0,0 +1,70 @@
+// Copyright 2017 The Abseil Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include "absl/strings/internal/str_format/output.h"
+
+#include <errno.h>
+#include <cstring>
+
+namespace absl {
+namespace str_format_internal {
+
+namespace {
+struct ClearErrnoGuard {
+ ClearErrnoGuard() : old_value(errno) { errno = 0; }
+ ~ClearErrnoGuard() {
+ if (!errno) errno = old_value;
+ }
+ int old_value;
+};
+} // namespace
+
+void BufferRawSink::Write(string_view v) {
+ size_t to_write = std::min(v.size(), size_);
+ std::memcpy(buffer_, v.data(), to_write);
+ buffer_ += to_write;
+ size_ -= to_write;
+ total_written_ += v.size();
+}
+
+void FILERawSink::Write(string_view v) {
+ while (!v.empty() && !error_) {
+ // Reset errno to zero in case the libc implementation doesn't set errno
+ // when a failure occurs.
+ ClearErrnoGuard guard;
+
+ if (size_t result = std::fwrite(v.data(), 1, v.size(), output_)) {
+ // Some progress was made.
+ count_ += result;
+ v.remove_prefix(result);
+ } else {
+ if (errno == EINTR) {
+ continue;
+ } else if (errno) {
+ error_ = errno;
+ } else if (std::ferror(output_)) {
+ // Non-POSIX compliant libc implementations may not set errno, so we
+ // have check the streams error indicator.
+ error_ = EBADF;
+ } else {
+ // We're likely on a non-POSIX system that encountered EINTR but had no
+ // way of reporting it.
+ continue;
+ }
+ }
+ }
+}
+
+} // namespace str_format_internal
+} // namespace absl
diff --git a/absl/strings/internal/str_format/output.h b/absl/strings/internal/str_format/output.h
new file mode 100644
index 0000000..42da641
--- /dev/null
+++ b/absl/strings/internal/str_format/output.h
@@ -0,0 +1,101 @@
+// Copyright 2017 The Abseil Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+// Output extension hooks for the Format library.
+// `internal::InvokeFlush` calls the appropriate flush function for the
+// specified output argument.
+// `BufferRawSink` is a simple output sink for a char buffer. Used by SnprintF.
+// `FILERawSink` is a std::FILE* based sink. Used by PrintF and FprintF.
+
+#ifndef ABSL_STRINGS_INTERNAL_STR_FORMAT_OUTPUT_H_
+#define ABSL_STRINGS_INTERNAL_STR_FORMAT_OUTPUT_H_
+
+#include <cstdio>
+#include <ostream>
+#include <string>
+
+#include "absl/base/port.h"
+#include "absl/strings/string_view.h"
+
+class Cord;
+
+namespace absl {
+namespace str_format_internal {
+
+// RawSink implementation that writes into a char* buffer.
+// It will not overflow the buffer, but will keep the total count of chars
+// that would have been written.
+class BufferRawSink {
+ public:
+ BufferRawSink(char* buffer, size_t size) : buffer_(buffer), size_(size) {}
+
+ size_t total_written() const { return total_written_; }
+ void Write(string_view v);
+
+ private:
+ char* buffer_;
+ size_t size_;
+ size_t total_written_ = 0;
+};
+
+// RawSink implementation that writes into a FILE*.
+// It keeps track of the total number of bytes written and any error encountered
+// during the writes.
+class FILERawSink {
+ public:
+ explicit FILERawSink(std::FILE* output) : output_(output) {}
+
+ void Write(string_view v);
+
+ size_t count() const { return count_; }
+ int error() const { return error_; }
+
+ private:
+ std::FILE* output_;
+ int error_ = 0;
+ size_t count_ = 0;
+};
+
+// Provide RawSink integration with common types from the STL.
+inline void AbslFormatFlush(std::string* out, string_view s) {
+ out->append(s.data(), s.size());
+}
+inline void AbslFormatFlush(std::ostream* out, string_view s) {
+ out->write(s.data(), s.size());
+}
+
+template <class AbslCord, typename = typename std::enable_if<
+ std::is_same<AbslCord, ::Cord>::value>::type>
+inline void AbslFormatFlush(AbslCord* out, string_view s) {
+ out->Append(s);
+}
+
+inline void AbslFormatFlush(FILERawSink* sink, string_view v) {
+ sink->Write(v);
+}
+
+inline void AbslFormatFlush(BufferRawSink* sink, string_view v) {
+ sink->Write(v);
+}
+
+template <typename T>
+auto InvokeFlush(T* out, string_view s)
+ -> decltype(str_format_internal::AbslFormatFlush(out, s)) {
+ str_format_internal::AbslFormatFlush(out, s);
+}
+
+} // namespace str_format_internal
+} // namespace absl
+
+#endif // ABSL_STRINGS_INTERNAL_STR_FORMAT_OUTPUT_H_
diff --git a/absl/strings/internal/str_format/output_test.cc b/absl/strings/internal/str_format/output_test.cc
new file mode 100644
index 0000000..6e04abe
--- /dev/null
+++ b/absl/strings/internal/str_format/output_test.cc
@@ -0,0 +1,71 @@
+// Copyright 2017 The Abseil Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include "absl/strings/internal/str_format/output.h"
+
+#include <sstream>
+#include <string>
+
+#include "gmock/gmock.h"
+#include "gtest/gtest.h"
+
+namespace absl {
+namespace {
+
+TEST(InvokeFlush, String) {
+ std::string str = "ABC";
+ str_format_internal::InvokeFlush(&str, "DEF");
+ EXPECT_EQ(str, "ABCDEF");
+}
+
+TEST(InvokeFlush, Stream) {
+ std::stringstream str;
+ str << "ABC";
+ str_format_internal::InvokeFlush(&str, "DEF");
+ EXPECT_EQ(str.str(), "ABCDEF");
+}
+
+TEST(BufferRawSink, Limits) {
+ char buf[16];
+ {
+ std::fill(std::begin(buf), std::end(buf), 'x');
+ str_format_internal::BufferRawSink bufsink(buf, sizeof(buf) - 1);
+ str_format_internal::InvokeFlush(&bufsink, "Hello World237");
+ EXPECT_EQ(std::string(buf, sizeof(buf)), "Hello World237xx");
+ }
+ {
+ std::fill(std::begin(buf), std::end(buf), 'x');
+ str_format_internal::BufferRawSink bufsink(buf, sizeof(buf) - 1);
+ str_format_internal::InvokeFlush(&bufsink, "Hello World237237");
+ EXPECT_EQ(std::string(buf, sizeof(buf)), "Hello World2372x");
+ }
+ {
+ std::fill(std::begin(buf), std::end(buf), 'x');
+ str_format_internal::BufferRawSink bufsink(buf, sizeof(buf) - 1);
+ str_format_internal::InvokeFlush(&bufsink, "Hello World");
+ str_format_internal::InvokeFlush(&bufsink, "237");
+ EXPECT_EQ(std::string(buf, sizeof(buf)), "Hello World237xx");
+ }
+ {
+ std::fill(std::begin(buf), std::end(buf), 'x');
+ str_format_internal::BufferRawSink bufsink(buf, sizeof(buf) - 1);
+ str_format_internal::InvokeFlush(&bufsink, "Hello World");
+ str_format_internal::InvokeFlush(&bufsink, "237237");
+ EXPECT_EQ(std::string(buf, sizeof(buf)), "Hello World2372x");
+ }
+}
+
+} // namespace
+} // namespace absl
+
diff --git a/absl/strings/internal/str_format/parser.cc b/absl/strings/internal/str_format/parser.cc
new file mode 100644
index 0000000..9ef5615
--- /dev/null
+++ b/absl/strings/internal/str_format/parser.cc
@@ -0,0 +1,303 @@
+#include "absl/strings/internal/str_format/parser.h"
+
+#include <assert.h>
+#include <string.h>
+#include <wchar.h>
+#include <cctype>
+#include <cstdint>
+
+#include <algorithm>
+#include <initializer_list>
+#include <limits>
+#include <ostream>
+#include <string>
+#include <unordered_set>
+
+namespace absl {
+namespace str_format_internal {
+
+using CC = ConversionChar::Id;
+using LM = LengthMod::Id;
+ABSL_CONST_INIT const ConvTag kTags[256] = {
+ {}, {}, {}, {}, {}, {}, {}, {}, // 00-07
+ {}, {}, {}, {}, {}, {}, {}, {}, // 08-0f
+ {}, {}, {}, {}, {}, {}, {}, {}, // 10-17
+ {}, {}, {}, {}, {}, {}, {}, {}, // 18-1f
+ {}, {}, {}, {}, {}, {}, {}, {}, // 20-27
+ {}, {}, {}, {}, {}, {}, {}, {}, // 28-2f
+ {}, {}, {}, {}, {}, {}, {}, {}, // 30-37
+ {}, {}, {}, {}, {}, {}, {}, {}, // 38-3f
+ {}, CC::A, {}, CC::C, {}, CC::E, CC::F, CC::G, // @ABCDEFG
+ {}, {}, {}, {}, LM::L, {}, {}, {}, // HIJKLMNO
+ {}, {}, {}, CC::S, {}, {}, {}, {}, // PQRSTUVW
+ CC::X, {}, {}, {}, {}, {}, {}, {}, // XYZ[\]^_
+ {}, CC::a, {}, CC::c, CC::d, CC::e, CC::f, CC::g, // `abcdefg
+ LM::h, CC::i, LM::j, {}, LM::l, {}, CC::n, CC::o, // hijklmno
+ CC::p, LM::q, {}, CC::s, LM::t, CC::u, {}, {}, // pqrstuvw
+ CC::x, {}, LM::z, {}, {}, {}, {}, {}, // xyz{|}!
+ {}, {}, {}, {}, {}, {}, {}, {}, // 80-87
+ {}, {}, {}, {}, {}, {}, {}, {}, // 88-8f
+ {}, {}, {}, {}, {}, {}, {}, {}, // 90-97
+ {}, {}, {}, {}, {}, {}, {}, {}, // 98-9f
+ {}, {}, {}, {}, {}, {}, {}, {}, // a0-a7
+ {}, {}, {}, {}, {}, {}, {}, {}, // a8-af
+ {}, {}, {}, {}, {}, {}, {}, {}, // b0-b7
+ {}, {}, {}, {}, {}, {}, {}, {}, // b8-bf
+ {}, {}, {}, {}, {}, {}, {}, {}, // c0-c7
+ {}, {}, {}, {}, {}, {}, {}, {}, // c8-cf
+ {}, {}, {}, {}, {}, {}, {}, {}, // d0-d7
+ {}, {}, {}, {}, {}, {}, {}, {}, // d8-df
+ {}, {}, {}, {}, {}, {}, {}, {}, // e0-e7
+ {}, {}, {}, {}, {}, {}, {}, {}, // e8-ef
+ {}, {}, {}, {}, {}, {}, {}, {}, // f0-f7
+ {}, {}, {}, {}, {}, {}, {}, {}, // f8-ff
+};
+
+namespace {
+
+bool CheckFastPathSetting(const UnboundConversion& conv) {
+ bool should_be_basic = !conv.flags.left && //
+ !conv.flags.show_pos && //
+ !conv.flags.sign_col && //
+ !conv.flags.alt && //
+ !conv.flags.zero && //
+ (conv.width.value() == -1) &&
+ (conv.precision.value() == -1);
+ if (should_be_basic != conv.flags.basic) {
+ fprintf(stderr,
+ "basic=%d left=%d show_pos=%d sign_col=%d alt=%d zero=%d "
+ "width=%d precision=%d\n",
+ conv.flags.basic, conv.flags.left, conv.flags.show_pos,
+ conv.flags.sign_col, conv.flags.alt, conv.flags.zero,
+ conv.width.value(), conv.precision.value());
+ }
+ return should_be_basic == conv.flags.basic;
+}
+
+template <bool is_positional>
+const char *ConsumeConversion(const char *pos, const char *const end,
+ UnboundConversion *conv, int *next_arg) {
+ const char* const original_pos = pos;
+ char c;
+ // Read the next char into `c` and update `pos`. Returns false if there are
+ // no more chars to read.
+#define ABSL_FORMAT_PARSER_INTERNAL_GET_CHAR() \
+ do { \
+ if (ABSL_PREDICT_FALSE(pos == end)) return nullptr; \
+ c = *pos++; \
+ } while (0)
+
+ const auto parse_digits = [&] {
+ int digits = c - '0';
+ // We do not want to overflow `digits` so we consume at most digits10
+ // digits. If there are more digits the parsing will fail later on when the
+ // digit doesn't match the expected characters.
+ int num_digits = std::numeric_limits<int>::digits10;
+ for (;;) {
+ if (ABSL_PREDICT_FALSE(pos == end)) break;
+ c = *pos++;
+ if (!std::isdigit(c)) break;
+ --num_digits;
+ if (ABSL_PREDICT_FALSE(!num_digits)) break;
+ digits = 10 * digits + c - '0';
+ }
+ return digits;
+ };
+
+ if (is_positional) {
+ ABSL_FORMAT_PARSER_INTERNAL_GET_CHAR();
+ if (ABSL_PREDICT_FALSE(c < '1' || c > '9')) return nullptr;
+ conv->arg_position = parse_digits();
+ assert(conv->arg_position > 0);
+ if (ABSL_PREDICT_FALSE(c != '$')) return nullptr;
+ }
+
+ ABSL_FORMAT_PARSER_INTERNAL_GET_CHAR();
+
+ // We should start with the basic flag on.
+ assert(conv->flags.basic);
+
+ // Any non alpha character makes this conversion not basic.
+ // This includes flags (-+ #0), width (1-9, *) or precision (.).
+ // All conversion characters and length modifiers are alpha characters.
+ if (c < 'A') {
+ conv->flags.basic = false;
+
+ for (; c <= '0';) {
+ // FIXME: We might be able to speed this up reusing the lookup table from
+ // above. It might require changing Flags to be a plain integer where we
+ // can |= a value.
+ switch (c) {
+ case '-':
+ conv->flags.left = true;
+ break;
+ case '+':
+ conv->flags.show_pos = true;
+ break;
+ case ' ':
+ conv->flags.sign_col = true;
+ break;
+ case '#':
+ conv->flags.alt = true;
+ break;
+ case '0':
+ conv->flags.zero = true;
+ break;
+ default:
+ goto flags_done;
+ }
+ ABSL_FORMAT_PARSER_INTERNAL_GET_CHAR();
+ }
+flags_done:
+
+ if (c <= '9') {
+ if (c >= '0') {
+ int maybe_width = parse_digits();
+ if (!is_positional && c == '$') {
+ if (ABSL_PREDICT_FALSE(*next_arg != 0)) return nullptr;
+ // Positional conversion.
+ *next_arg = -1;
+ conv->flags = Flags();
+ conv->flags.basic = true;
+ return ConsumeConversion<true>(original_pos, end, conv, next_arg);
+ }
+ conv->width.set_value(maybe_width);
+ } else if (c == '*') {
+ ABSL_FORMAT_PARSER_INTERNAL_GET_CHAR();
+ if (is_positional) {
+ if (ABSL_PREDICT_FALSE(c < '1' || c > '9')) return nullptr;
+ conv->width.set_from_arg(parse_digits());
+ if (ABSL_PREDICT_FALSE(c != '$')) return nullptr;
+ ABSL_FORMAT_PARSER_INTERNAL_GET_CHAR();
+ } else {
+ conv->width.set_from_arg(++*next_arg);
+ }
+ }
+ }
+
+ if (c == '.') {
+ ABSL_FORMAT_PARSER_INTERNAL_GET_CHAR();
+ if (std::isdigit(c)) {
+ conv->precision.set_value(parse_digits());
+ } else if (c == '*') {
+ ABSL_FORMAT_PARSER_INTERNAL_GET_CHAR();
+ if (is_positional) {
+ if (ABSL_PREDICT_FALSE(c < '1' || c > '9')) return nullptr;
+ conv->precision.set_from_arg(parse_digits());
+ if (c != '$') return nullptr;
+ ABSL_FORMAT_PARSER_INTERNAL_GET_CHAR();
+ } else {
+ conv->precision.set_from_arg(++*next_arg);
+ }
+ } else {
+ conv->precision.set_value(0);
+ }
+ }
+ }
+
+ auto tag = GetTagForChar(c);
+
+ if (ABSL_PREDICT_FALSE(!tag.is_conv())) {
+ if (ABSL_PREDICT_FALSE(!tag.is_length())) return nullptr;
+
+ // It is a length modifier.
+ using str_format_internal::LengthMod;
+ LengthMod length_mod = tag.as_length();
+ ABSL_FORMAT_PARSER_INTERNAL_GET_CHAR();
+ if (c == 'h' && length_mod.id() == LengthMod::h) {
+ conv->length_mod = LengthMod::FromId(LengthMod::hh);
+ ABSL_FORMAT_PARSER_INTERNAL_GET_CHAR();
+ } else if (c == 'l' && length_mod.id() == LengthMod::l) {
+ conv->length_mod = LengthMod::FromId(LengthMod::ll);
+ ABSL_FORMAT_PARSER_INTERNAL_GET_CHAR();
+ } else {
+ conv->length_mod = length_mod;
+ }
+ tag = GetTagForChar(c);
+ if (ABSL_PREDICT_FALSE(!tag.is_conv())) return nullptr;
+ }
+
+ assert(CheckFastPathSetting(*conv));
+ (void)(&CheckFastPathSetting);
+
+ conv->conv = tag.as_conv();
+ if (!is_positional) conv->arg_position = ++*next_arg;
+ return pos;
+}
+
+} // namespace
+
+const char *ConsumeUnboundConversion(const char *p, const char *end,
+ UnboundConversion *conv, int *next_arg) {
+ if (*next_arg < 0) return ConsumeConversion<true>(p, end, conv, next_arg);
+ return ConsumeConversion<false>(p, end, conv, next_arg);
+}
+
+struct ParsedFormatBase::ParsedFormatConsumer {
+ explicit ParsedFormatConsumer(ParsedFormatBase *parsedformat)
+ : parsed(parsedformat), data_pos(parsedformat->data_.get()) {}
+
+ bool Append(string_view s) {
+ if (s.empty()) return true;
+
+ size_t text_end = AppendText(s);
+
+ if (!parsed->items_.empty() && !parsed->items_.back().is_conversion) {
+ // Let's extend the existing text run.
+ parsed->items_.back().text_end = text_end;
+ } else {
+ // Let's make a new text run.
+ parsed->items_.push_back({false, text_end, {}});
+ }
+ return true;
+ }
+
+ bool ConvertOne(const UnboundConversion &conv, string_view s) {
+ size_t text_end = AppendText(s);
+ parsed->items_.push_back({true, text_end, conv});
+ return true;
+ }
+
+ size_t AppendText(string_view s) {
+ memcpy(data_pos, s.data(), s.size());
+ data_pos += s.size();
+ return static_cast<size_t>(data_pos - parsed->data_.get());
+ }
+
+ ParsedFormatBase *parsed;
+ char* data_pos;
+};
+
+ParsedFormatBase::ParsedFormatBase(string_view format, bool allow_ignored,
+ std::initializer_list<Conv> convs)
+ : data_(format.empty() ? nullptr : new char[format.size()]) {
+ has_error_ = !ParseFormatString(format, ParsedFormatConsumer(this)) ||
+ !MatchesConversions(allow_ignored, convs);
+}
+
+bool ParsedFormatBase::MatchesConversions(
+ bool allow_ignored, std::initializer_list<Conv> convs) const {
+ std::unordered_set<int> used;
+ auto add_if_valid_conv = [&](int pos, char c) {
+ if (static_cast<size_t>(pos) > convs.size() ||
+ !Contains(convs.begin()[pos - 1], c))
+ return false;
+ used.insert(pos);
+ return true;
+ };
+ for (const ConversionItem &item : items_) {
+ if (!item.is_conversion) continue;
+ auto &conv = item.conv;
+ if (conv.precision.is_from_arg() &&
+ !add_if_valid_conv(conv.precision.get_from_arg(), '*'))
+ return false;
+ if (conv.width.is_from_arg() &&
+ !add_if_valid_conv(conv.width.get_from_arg(), '*'))
+ return false;
+ if (!add_if_valid_conv(conv.arg_position, conv.conv.Char())) return false;
+ }
+ return used.size() == convs.size() || allow_ignored;
+}
+
+} // namespace str_format_internal
+} // namespace absl
diff --git a/absl/strings/internal/str_format/parser.h b/absl/strings/internal/str_format/parser.h
new file mode 100644
index 0000000..b7614a0
--- /dev/null
+++ b/absl/strings/internal/str_format/parser.h
@@ -0,0 +1,322 @@
+#ifndef ABSL_STRINGS_INTERNAL_STR_FORMAT_PARSER_H_
+#define ABSL_STRINGS_INTERNAL_STR_FORMAT_PARSER_H_
+
+#include <limits.h>
+#include <stddef.h>
+#include <stdlib.h>
+
+#include <cassert>
+#include <initializer_list>
+#include <iosfwd>
+#include <iterator>
+#include <memory>
+#include <vector>
+
+#include "absl/strings/internal/str_format/checker.h"
+#include "absl/strings/internal/str_format/extension.h"
+
+namespace absl {
+namespace str_format_internal {
+
+// The analyzed properties of a single specified conversion.
+struct UnboundConversion {
+ UnboundConversion()
+ : flags() /* This is required to zero all the fields of flags. */ {
+ flags.basic = true;
+ }
+
+ class InputValue {
+ public:
+ void set_value(int value) {
+ assert(value >= 0);
+ value_ = value;
+ }
+ int value() const { return value_; }
+
+ // Marks the value as "from arg". aka the '*' format.
+ // Requires `value >= 1`.
+ // When set, is_from_arg() return true and get_from_arg() returns the
+ // original value.
+ // `value()`'s return value is unspecfied in this state.
+ void set_from_arg(int value) {
+ assert(value > 0);
+ value_ = -value - 1;
+ }
+ bool is_from_arg() const { return value_ < -1; }
+ int get_from_arg() const {
+ assert(is_from_arg());
+ return -value_ - 1;
+ }
+
+ private:
+ int value_ = -1;
+ };
+
+ // No need to initialize. It will always be set in the parser.
+ int arg_position;
+
+ InputValue width;
+ InputValue precision;
+
+ Flags flags;
+ LengthMod length_mod;
+ ConversionChar conv;
+};
+
+// Consume conversion spec prefix (not including '%') of [p, end) if valid.
+// Examples of valid specs would be e.g.: "s", "d", "-12.6f".
+// If valid, it returns the first character following the conversion spec,
+// and the spec part is broken down and returned in 'conv'.
+// If invalid, returns nullptr.
+const char* ConsumeUnboundConversion(const char* p, const char* end,
+ UnboundConversion* conv, int* next_arg);
+
+// Helper tag class for the table below.
+// It allows fast `char -> ConversionChar/LengthMod` checking and conversions.
+class ConvTag {
+ public:
+ constexpr ConvTag(ConversionChar::Id id) : tag_(id) {} // NOLINT
+ // We invert the length modifiers to make them negative so that we can easily
+ // test for them.
+ constexpr ConvTag(LengthMod::Id id) : tag_(~id) {} // NOLINT
+ // Everything else is -128, which is negative to make is_conv() simpler.
+ constexpr ConvTag() : tag_(-128) {}
+
+ bool is_conv() const { return tag_ >= 0; }
+ bool is_length() const { return tag_ < 0 && tag_ != -128; }
+ ConversionChar as_conv() const {
+ assert(is_conv());
+ return ConversionChar::FromId(static_cast<ConversionChar::Id>(tag_));
+ }
+ LengthMod as_length() const {
+ assert(is_length());
+ return LengthMod::FromId(static_cast<LengthMod::Id>(~tag_));
+ }
+
+ private:
+ std::int8_t tag_;
+};
+
+extern const ConvTag kTags[256];
+// Keep a single table for all the conversion chars and length modifiers.
+inline ConvTag GetTagForChar(char c) {
+ return kTags[static_cast<unsigned char>(c)];
+}
+
+// Parse the format string provided in 'src' and pass the identified items into
+// 'consumer'.
+// Text runs will be passed by calling
+// Consumer::Append(string_view);
+// ConversionItems will be passed by calling
+// Consumer::ConvertOne(UnboundConversion, string_view);
+// In the case of ConvertOne, the string_view that is passed is the
+// portion of the format string corresponding to the conversion, not including
+// the leading %. On success, it returns true. On failure, it stops and returns
+// false.
+template <typename Consumer>
+bool ParseFormatString(string_view src, Consumer consumer) {
+ int next_arg = 0;
+ const char* p = src.data();
+ const char* const end = p + src.size();
+ while (p != end) {
+ const char* percent = static_cast<const char*>(memchr(p, '%', end - p));
+ if (!percent) {
+ // We found the last substring.
+ return consumer.Append(string_view(p, end - p));
+ }
+ // We found a percent, so push the text run then process the percent.
+ if (ABSL_PREDICT_FALSE(!consumer.Append(string_view(p, percent - p)))) {
+ return false;
+ }
+ if (ABSL_PREDICT_FALSE(percent + 1 >= end)) return false;
+
+ auto tag = GetTagForChar(percent[1]);
+ if (tag.is_conv()) {
+ if (ABSL_PREDICT_FALSE(next_arg < 0)) {
+ // This indicates an error in the format std::string.
+ // The only way to get `next_arg < 0` here is to have a positional
+ // argument first which sets next_arg to -1 and then a non-positional
+ // argument.
+ return false;
+ }
+ p = percent + 2;
+
+ // Keep this case separate from the one below.
+ // ConvertOne is more efficient when the compiler can see that the `basic`
+ // flag is set.
+ UnboundConversion conv;
+ conv.conv = tag.as_conv();
+ conv.arg_position = ++next_arg;
+ if (ABSL_PREDICT_FALSE(
+ !consumer.ConvertOne(conv, string_view(percent + 1, 1)))) {
+ return false;
+ }
+ } else if (percent[1] != '%') {
+ UnboundConversion conv;
+ p = ConsumeUnboundConversion(percent + 1, end, &conv, &next_arg);
+ if (ABSL_PREDICT_FALSE(p == nullptr)) return false;
+ if (ABSL_PREDICT_FALSE(!consumer.ConvertOne(
+ conv, string_view(percent + 1, p - (percent + 1))))) {
+ return false;
+ }
+ } else {
+ if (ABSL_PREDICT_FALSE(!consumer.Append("%"))) return false;
+ p = percent + 2;
+ continue;
+ }
+ }
+ return true;
+}
+
+// Always returns true, or fails to compile in a constexpr context if s does not
+// point to a constexpr char array.
+constexpr bool EnsureConstexpr(string_view s) {
+ return s.empty() || s[0] == s[0];
+}
+
+class ParsedFormatBase {
+ public:
+ explicit ParsedFormatBase(string_view format, bool allow_ignored,
+ std::initializer_list<Conv> convs);
+
+ ParsedFormatBase(const ParsedFormatBase& other) { *this = other; }
+
+ ParsedFormatBase(ParsedFormatBase&& other) { *this = std::move(other); }
+
+ ParsedFormatBase& operator=(const ParsedFormatBase& other) {
+ if (this == &other) return *this;
+ has_error_ = other.has_error_;
+ items_ = other.items_;
+ size_t text_size = items_.empty() ? 0 : items_.back().text_end;
+ data_.reset(new char[text_size]);
+ memcpy(data_.get(), other.data_.get(), text_size);
+ return *this;
+ }
+
+ ParsedFormatBase& operator=(ParsedFormatBase&& other) {
+ if (this == &other) return *this;
+ has_error_ = other.has_error_;
+ data_ = std::move(other.data_);
+ items_ = std::move(other.items_);
+ // Reset the vector to make sure the invariants hold.
+ other.items_.clear();
+ return *this;
+ }
+
+ template <typename Consumer>
+ bool ProcessFormat(Consumer consumer) const {
+ const char* const base = data_.get();
+ string_view text(base, 0);
+ for (const auto& item : items_) {
+ const char* const end = text.data() + text.size();
+ text = string_view(end, (base + item.text_end) - end);
+ if (item.is_conversion) {
+ if (!consumer.ConvertOne(item.conv, text)) return false;
+ } else {
+ if (!consumer.Append(text)) return false;
+ }
+ }
+ return !has_error_;
+ }
+
+ bool has_error() const { return has_error_; }
+
+ private:
+ // Returns whether the conversions match and if !allow_ignored it verifies
+ // that all conversions are used by the format.
+ bool MatchesConversions(bool allow_ignored,
+ std::initializer_list<Conv> convs) const;
+
+ struct ParsedFormatConsumer;
+
+ struct ConversionItem {
+ bool is_conversion;
+ // Points to the past-the-end location of this element in the data_ array.
+ size_t text_end;
+ UnboundConversion conv;
+ };
+
+ bool has_error_;
+ std::unique_ptr<char[]> data_;
+ std::vector<ConversionItem> items_;
+};
+
+
+// A value type representing a preparsed format. These can be created, copied
+// around, and reused to speed up formatting loops.
+// The user must specify through the template arguments the conversion
+// characters used in the format. This will be checked at compile time.
+//
+// This class uses Conv enum values to specify each argument.
+// This allows for more flexibility as you can specify multiple possible
+// conversion characters for each argument.
+// ParsedFormat<char...> is a simplified alias for when the user only
+// needs to specify a single conversion character for each argument.
+//
+// Example:
+// // Extended format supports multiple characters per argument:
+// using MyFormat = ExtendedParsedFormat<Conv::d | Conv::x>;
+// MyFormat GetFormat(bool use_hex) {
+// if (use_hex) return MyFormat("foo %x bar");
+// return MyFormat("foo %d bar");
+// }
+// // 'format' can be used with any value that supports 'd' and 'x',
+// // like `int`.
+// auto format = GetFormat(use_hex);
+// value = StringF(format, i);
+//
+// This class also supports runtime format checking with the ::New() and
+// ::NewAllowIgnored() factory functions.
+// This is the only API that allows the user to pass a runtime specified format
+// string. These factory functions will return NULL if the format does not match
+// the conversions requested by the user.
+template <str_format_internal::Conv... C>
+class ExtendedParsedFormat : public str_format_internal::ParsedFormatBase {
+ public:
+ explicit ExtendedParsedFormat(string_view format)
+#if ABSL_INTERNAL_ENABLE_FORMAT_CHECKER
+ __attribute__((
+ enable_if(str_format_internal::EnsureConstexpr(format),
+ "Format std::string is not constexpr."),
+ enable_if(str_format_internal::ValidFormatImpl<C...>(format),
+ "Format specified does not match the template arguments.")))
+#endif // ABSL_INTERNAL_ENABLE_FORMAT_CHECKER
+ : ExtendedParsedFormat(format, false) {
+ }
+
+ // ExtendedParsedFormat factory function.
+ // The user still has to specify the conversion characters, but they will not
+ // be checked at compile time. Instead, it will be checked at runtime.
+ // This delays the checking to runtime, but allows the user to pass
+ // dynamically sourced formats.
+ // It returns NULL if the format does not match the conversion characters.
+ // The user is responsible for checking the return value before using it.
+ //
+ // The 'New' variant will check that all the specified arguments are being
+ // consumed by the format and return NULL if any argument is being ignored.
+ // The 'NewAllowIgnored' variant will not verify this and will allow formats
+ // that ignore arguments.
+ static std::unique_ptr<ExtendedParsedFormat> New(string_view format) {
+ return New(format, false);
+ }
+ static std::unique_ptr<ExtendedParsedFormat> NewAllowIgnored(
+ string_view format) {
+ return New(format, true);
+ }
+
+ private:
+ static std::unique_ptr<ExtendedParsedFormat> New(string_view format,
+ bool allow_ignored) {
+ std::unique_ptr<ExtendedParsedFormat> conv(
+ new ExtendedParsedFormat(format, allow_ignored));
+ if (conv->has_error()) return nullptr;
+ return conv;
+ }
+
+ ExtendedParsedFormat(string_view s, bool allow_ignored)
+ : ParsedFormatBase(s, allow_ignored, {C...}) {}
+};
+} // namespace str_format_internal
+} // namespace absl
+
+#endif // ABSL_STRINGS_INTERNAL_STR_FORMAT_PARSER_H_
diff --git a/absl/strings/internal/str_format/parser_test.cc b/absl/strings/internal/str_format/parser_test.cc
new file mode 100644
index 0000000..6d356093
--- /dev/null
+++ b/absl/strings/internal/str_format/parser_test.cc
@@ -0,0 +1,392 @@
+#include "absl/strings/internal/str_format/parser.h"
+
+#include <string.h>
+
+#include "gmock/gmock.h"
+#include "gtest/gtest.h"
+#include "absl/base/macros.h"
+
+namespace absl {
+namespace str_format_internal {
+
+namespace {
+
+using testing::Pair;
+
+TEST(LengthModTest, Names) {
+ struct Expectation {
+ int line;
+ LengthMod::Id id;
+ const char *name;
+ };
+ const Expectation kExpect[] = {
+ {__LINE__, LengthMod::none, "" },
+ {__LINE__, LengthMod::h, "h" },
+ {__LINE__, LengthMod::hh, "hh"},
+ {__LINE__, LengthMod::l, "l" },
+ {__LINE__, LengthMod::ll, "ll"},
+ {__LINE__, LengthMod::L, "L" },
+ {__LINE__, LengthMod::j, "j" },
+ {__LINE__, LengthMod::z, "z" },
+ {__LINE__, LengthMod::t, "t" },
+ {__LINE__, LengthMod::q, "q" },
+ };
+ EXPECT_EQ(ABSL_ARRAYSIZE(kExpect), LengthMod::kNumValues);
+ for (auto e : kExpect) {
+ SCOPED_TRACE(e.line);
+ LengthMod mod = LengthMod::FromId(e.id);
+ EXPECT_EQ(e.id, mod.id());
+ EXPECT_EQ(e.name, mod.name());
+ }
+}
+
+TEST(ConversionCharTest, Names) {
+ struct Expectation {
+ ConversionChar::Id id;
+ char name;
+ };
+ // clang-format off
+ const Expectation kExpect[] = {
+#define X(c) {ConversionChar::c, #c[0]}
+ X(c), X(C), X(s), X(S), // text
+ X(d), X(i), X(o), X(u), X(x), X(X), // int
+ X(f), X(F), X(e), X(E), X(g), X(G), X(a), X(A), // float
+ X(n), X(p), // misc
+#undef X
+ {ConversionChar::none, '\0'},
+ };
+ // clang-format on
+ EXPECT_EQ(ABSL_ARRAYSIZE(kExpect), ConversionChar::kNumValues);
+ for (auto e : kExpect) {
+ SCOPED_TRACE(e.name);
+ ConversionChar v = ConversionChar::FromId(e.id);
+ EXPECT_EQ(e.id, v.id());
+ EXPECT_EQ(e.name, v.Char());
+ }
+}
+
+class ConsumeUnboundConversionTest : public ::testing::Test {
+ public:
+ std::pair<string_view, string_view> Consume(string_view src) {
+ int next = 0;
+ o = UnboundConversion(); // refresh
+ const char* p = ConsumeUnboundConversion(
+ src.data(), src.data() + src.size(), &o, &next);
+ if (!p) return {{}, src};
+ return {string_view(src.data(), p - src.data()),
+ string_view(p, src.data() + src.size() - p)};
+ }
+
+ bool Run(const char *fmt, bool force_positional = false) {
+ int next = force_positional ? -1 : 0;
+ o = UnboundConversion(); // refresh
+ return ConsumeUnboundConversion(fmt, fmt + strlen(fmt), &o, &next) ==
+ fmt + strlen(fmt);
+ }
+ UnboundConversion o;
+};
+
+TEST_F(ConsumeUnboundConversionTest, ConsumeSpecification) {
+ struct Expectation {
+ int line;
+ string_view src;
+ string_view out;
+ string_view src_post;
+ };
+ const Expectation kExpect[] = {
+ {__LINE__, "", "", "" },
+ {__LINE__, "b", "", "b" }, // 'b' is invalid
+ {__LINE__, "ba", "", "ba"}, // 'b' is invalid
+ {__LINE__, "l", "", "l" }, // just length mod isn't okay
+ {__LINE__, "d", "d", "" }, // basic
+ {__LINE__, "d ", "d", " " }, // leave suffix
+ {__LINE__, "dd", "d", "d" }, // don't be greedy
+ {__LINE__, "d9", "d", "9" }, // leave non-space suffix
+ {__LINE__, "dzz", "d", "zz"}, // length mod as suffix
+ {__LINE__, "1$*2$d", "1$*2$d", "" }, // arg indexing and * allowed.
+ {__LINE__, "0-14.3hhd", "0-14.3hhd", ""}, // precision, width
+ {__LINE__, " 0-+#14.3hhd", " 0-+#14.3hhd", ""}, // flags
+ };
+ for (const auto& e : kExpect) {
+ SCOPED_TRACE(e.line);
+ EXPECT_THAT(Consume(e.src), Pair(e.out, e.src_post));
+ }
+}
+
+TEST_F(ConsumeUnboundConversionTest, BasicConversion) {
+ EXPECT_FALSE(Run(""));
+ EXPECT_FALSE(Run("z"));
+
+ EXPECT_FALSE(Run("dd")); // no excess allowed
+
+ EXPECT_TRUE(Run("d"));
+ EXPECT_EQ('d', o.conv.Char());
+ EXPECT_FALSE(o.width.is_from_arg());
+ EXPECT_LT(o.width.value(), 0);
+ EXPECT_FALSE(o.precision.is_from_arg());
+ EXPECT_LT(o.precision.value(), 0);
+ EXPECT_EQ(1, o.arg_position);
+ EXPECT_EQ(LengthMod::none, o.length_mod.id());
+}
+
+TEST_F(ConsumeUnboundConversionTest, ArgPosition) {
+ EXPECT_TRUE(Run("d"));
+ EXPECT_EQ(1, o.arg_position);
+ EXPECT_TRUE(Run("3$d"));
+ EXPECT_EQ(3, o.arg_position);
+ EXPECT_TRUE(Run("1$d"));
+ EXPECT_EQ(1, o.arg_position);
+ EXPECT_TRUE(Run("1$d", true));
+ EXPECT_EQ(1, o.arg_position);
+ EXPECT_TRUE(Run("123$d"));
+ EXPECT_EQ(123, o.arg_position);
+ EXPECT_TRUE(Run("123$d", true));
+ EXPECT_EQ(123, o.arg_position);
+ EXPECT_TRUE(Run("10$d"));
+ EXPECT_EQ(10, o.arg_position);
+ EXPECT_TRUE(Run("10$d", true));
+ EXPECT_EQ(10, o.arg_position);
+
+ // Position can't be zero.
+ EXPECT_FALSE(Run("0$d"));
+ EXPECT_FALSE(Run("0$d", true));
+ EXPECT_FALSE(Run("1$*0$d"));
+ EXPECT_FALSE(Run("1$.*0$d"));
+
+ // Position can't start with a zero digit at all. That is not a 'decimal'.
+ EXPECT_FALSE(Run("01$p"));
+ EXPECT_FALSE(Run("01$p", true));
+ EXPECT_FALSE(Run("1$*01$p"));
+ EXPECT_FALSE(Run("1$.*01$p"));
+}
+
+TEST_F(ConsumeUnboundConversionTest, WidthAndPrecision) {
+ EXPECT_TRUE(Run("14d"));
+ EXPECT_EQ('d', o.conv.Char());
+ EXPECT_FALSE(o.width.is_from_arg());
+ EXPECT_EQ(14, o.width.value());
+ EXPECT_FALSE(o.precision.is_from_arg());
+ EXPECT_LT(o.precision.value(), 0);
+
+ EXPECT_TRUE(Run("14.d"));
+ EXPECT_FALSE(o.width.is_from_arg());
+ EXPECT_FALSE(o.precision.is_from_arg());
+ EXPECT_EQ(14, o.width.value());
+ EXPECT_EQ(0, o.precision.value());
+
+ EXPECT_TRUE(Run(".d"));
+ EXPECT_FALSE(o.width.is_from_arg());
+ EXPECT_LT(o.width.value(), 0);
+ EXPECT_FALSE(o.precision.is_from_arg());
+ EXPECT_EQ(0, o.precision.value());
+
+ EXPECT_TRUE(Run(".5d"));
+ EXPECT_FALSE(o.width.is_from_arg());
+ EXPECT_LT(o.width.value(), 0);
+ EXPECT_FALSE(o.precision.is_from_arg());
+ EXPECT_EQ(5, o.precision.value());
+
+ EXPECT_TRUE(Run(".0d"));
+ EXPECT_FALSE(o.width.is_from_arg());
+ EXPECT_LT(o.width.value(), 0);
+ EXPECT_FALSE(o.precision.is_from_arg());
+ EXPECT_EQ(0, o.precision.value());
+
+ EXPECT_TRUE(Run("14.5d"));
+ EXPECT_FALSE(o.width.is_from_arg());
+ EXPECT_FALSE(o.precision.is_from_arg());
+ EXPECT_EQ(14, o.width.value());
+ EXPECT_EQ(5, o.precision.value());
+
+ EXPECT_TRUE(Run("*.*d"));
+ EXPECT_TRUE(o.width.is_from_arg());
+ EXPECT_EQ(1, o.width.get_from_arg());
+ EXPECT_TRUE(o.precision.is_from_arg());
+ EXPECT_EQ(2, o.precision.get_from_arg());
+ EXPECT_EQ(3, o.arg_position);
+
+ EXPECT_TRUE(Run("*d"));
+ EXPECT_TRUE(o.width.is_from_arg());
+ EXPECT_EQ(1, o.width.get_from_arg());
+ EXPECT_FALSE(o.precision.is_from_arg());
+ EXPECT_LT(o.precision.value(), 0);
+ EXPECT_EQ(2, o.arg_position);
+
+ EXPECT_TRUE(Run(".*d"));
+ EXPECT_FALSE(o.width.is_from_arg());
+ EXPECT_LT(o.width.value(), 0);
+ EXPECT_TRUE(o.precision.is_from_arg());
+ EXPECT_EQ(1, o.precision.get_from_arg());
+ EXPECT_EQ(2, o.arg_position);
+
+ // mixed implicit and explicit: didn't specify arg position.
+ EXPECT_FALSE(Run("*23$.*34$d"));
+
+ EXPECT_TRUE(Run("12$*23$.*34$d"));
+ EXPECT_EQ(12, o.arg_position);
+ EXPECT_TRUE(o.width.is_from_arg());
+ EXPECT_EQ(23, o.width.get_from_arg());
+ EXPECT_TRUE(o.precision.is_from_arg());
+ EXPECT_EQ(34, o.precision.get_from_arg());
+
+ EXPECT_TRUE(Run("2$*5$.*9$d"));
+ EXPECT_EQ(2, o.arg_position);
+ EXPECT_TRUE(o.width.is_from_arg());
+ EXPECT_EQ(5, o.width.get_from_arg());
+ EXPECT_TRUE(o.precision.is_from_arg());
+ EXPECT_EQ(9, o.precision.get_from_arg());
+
+ EXPECT_FALSE(Run(".*0$d")) << "no arg 0";
+
+ // Large values
+ EXPECT_TRUE(Run("999999999.999999999d"));
+ EXPECT_FALSE(o.width.is_from_arg());
+ EXPECT_EQ(999999999, o.width.value());
+ EXPECT_FALSE(o.precision.is_from_arg());
+ EXPECT_EQ(999999999, o.precision.value());
+
+ EXPECT_FALSE(Run("1000000000.999999999d"));
+ EXPECT_FALSE(Run("999999999.1000000000d"));
+ EXPECT_FALSE(Run("9999999999d"));
+ EXPECT_FALSE(Run(".9999999999d"));
+}
+
+TEST_F(ConsumeUnboundConversionTest, Flags) {
+ static const char kAllFlags[] = "-+ #0";
+ static const int kNumFlags = ABSL_ARRAYSIZE(kAllFlags) - 1;
+ for (int rev = 0; rev < 2; ++rev) {
+ for (int i = 0; i < 1 << kNumFlags; ++i) {
+ std::string fmt;
+ for (int k = 0; k < kNumFlags; ++k)
+ if ((i >> k) & 1) fmt += kAllFlags[k];
+ // flag order shouldn't matter
+ if (rev == 1) { std::reverse(fmt.begin(), fmt.end()); }
+ fmt += 'd';
+ SCOPED_TRACE(fmt);
+ EXPECT_TRUE(Run(fmt.c_str()));
+ EXPECT_EQ(fmt.find('-') == std::string::npos, !o.flags.left);
+ EXPECT_EQ(fmt.find('+') == std::string::npos, !o.flags.show_pos);
+ EXPECT_EQ(fmt.find(' ') == std::string::npos, !o.flags.sign_col);
+ EXPECT_EQ(fmt.find('#') == std::string::npos, !o.flags.alt);
+ EXPECT_EQ(fmt.find('0') == std::string::npos, !o.flags.zero);
+ }
+ }
+}
+
+TEST_F(ConsumeUnboundConversionTest, BasicFlag) {
+ // Flag is on
+ for (const char* fmt : {"d", "llx", "G", "1$X"}) {
+ SCOPED_TRACE(fmt);
+ EXPECT_TRUE(Run(fmt));
+ EXPECT_TRUE(o.flags.basic);
+ }
+
+ // Flag is off
+ for (const char* fmt : {"3d", ".llx", "-G", "1$#X"}) {
+ SCOPED_TRACE(fmt);
+ EXPECT_TRUE(Run(fmt));
+ EXPECT_FALSE(o.flags.basic);
+ }
+}
+
+struct SummarizeConsumer {
+ std::string* out;
+ explicit SummarizeConsumer(std::string* out) : out(out) {}
+
+ bool Append(string_view s) {
+ *out += "[" + std::string(s) + "]";
+ return true;
+ }
+
+ bool ConvertOne(const UnboundConversion& conv, string_view s) {
+ *out += "{";
+ *out += std::string(s);
+ *out += ":";
+ *out += std::to_string(conv.arg_position) + "$";
+ if (conv.width.is_from_arg()) {
+ *out += std::to_string(conv.width.get_from_arg()) + "$*";
+ }
+ if (conv.precision.is_from_arg()) {
+ *out += "." + std::to_string(conv.precision.get_from_arg()) + "$*";
+ }
+ *out += conv.conv.Char();
+ *out += "}";
+ return true;
+ }
+};
+
+std::string SummarizeParsedFormat(const ParsedFormatBase& pc) {
+ std::string out;
+ if (!pc.ProcessFormat(SummarizeConsumer(&out))) out += "!";
+ return out;
+}
+
+class ParsedFormatTest : public testing::Test {};
+
+TEST_F(ParsedFormatTest, ValueSemantics) {
+ ParsedFormatBase p1({}, true, {}); // empty format
+ EXPECT_EQ("", SummarizeParsedFormat(p1));
+
+ ParsedFormatBase p2 = p1; // copy construct (empty)
+ EXPECT_EQ(SummarizeParsedFormat(p1), SummarizeParsedFormat(p2));
+
+ p1 = ParsedFormatBase("hello%s", true, {Conv::s}); // move assign
+ EXPECT_EQ("[hello]{s:1$s}", SummarizeParsedFormat(p1));
+
+ ParsedFormatBase p3 = p1; // copy construct (nonempty)
+ EXPECT_EQ(SummarizeParsedFormat(p1), SummarizeParsedFormat(p3));
+
+ using std::swap;
+ swap(p1, p2);
+ EXPECT_EQ("", SummarizeParsedFormat(p1));
+ EXPECT_EQ("[hello]{s:1$s}", SummarizeParsedFormat(p2));
+ swap(p1, p2); // undo
+
+ p2 = p1; // copy assign
+ EXPECT_EQ(SummarizeParsedFormat(p1), SummarizeParsedFormat(p2));
+}
+
+struct ExpectParse {
+ const char* in;
+ std::initializer_list<Conv> conv_set;
+ const char* out;
+};
+
+TEST_F(ParsedFormatTest, Parsing) {
+ // Parse should be equivalent to that obtained by ConversionParseIterator.
+ // No need to retest the parsing edge cases here.
+ const ExpectParse kExpect[] = {
+ {"", {}, ""},
+ {"ab", {}, "[ab]"},
+ {"a%d", {Conv::d}, "[a]{d:1$d}"},
+ {"a%+d", {Conv::d}, "[a]{+d:1$d}"},
+ {"a% d", {Conv::d}, "[a]{ d:1$d}"},
+ {"a%b %d", {}, "[a]!"}, // stop after error
+ };
+ for (const auto& e : kExpect) {
+ SCOPED_TRACE(e.in);
+ EXPECT_EQ(e.out,
+ SummarizeParsedFormat(ParsedFormatBase(e.in, false, e.conv_set)));
+ }
+}
+
+TEST_F(ParsedFormatTest, ParsingFlagOrder) {
+ const ExpectParse kExpect[] = {
+ {"a%+ 0d", {Conv::d}, "[a]{+ 0d:1$d}"},
+ {"a%+0 d", {Conv::d}, "[a]{+0 d:1$d}"},
+ {"a%0+ d", {Conv::d}, "[a]{0+ d:1$d}"},
+ {"a% +0d", {Conv::d}, "[a]{ +0d:1$d}"},
+ {"a%0 +d", {Conv::d}, "[a]{0 +d:1$d}"},
+ {"a% 0+d", {Conv::d}, "[a]{ 0+d:1$d}"},
+ {"a%+ 0+d", {Conv::d}, "[a]{+ 0+d:1$d}"},
+ };
+ for (const auto& e : kExpect) {
+ SCOPED_TRACE(e.in);
+ EXPECT_EQ(e.out,
+ SummarizeParsedFormat(ParsedFormatBase(e.in, false, e.conv_set)));
+ }
+}
+
+} // namespace
+} // namespace str_format_internal
+} // namespace absl
diff --git a/absl/strings/internal/str_join_internal.h b/absl/strings/internal/str_join_internal.h
new file mode 100644
index 0000000..7c35f4d
--- /dev/null
+++ b/absl/strings/internal/str_join_internal.h
@@ -0,0 +1,312 @@
+//
+// Copyright 2017 The Abseil Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+
+// This file declares INTERNAL parts of the Join API that are inlined/templated
+// or otherwise need to be available at compile time. The main abstractions
+// defined in this file are:
+//
+// - A handful of default Formatters
+// - JoinAlgorithm() overloads
+// - JoinRange() overloads
+// - JoinTuple()
+//
+// DO NOT INCLUDE THIS FILE DIRECTLY. Use this file by including
+// absl/strings/str_join.h
+//
+// IWYU pragma: private, include "absl/strings/str_join.h"
+
+#ifndef ABSL_STRINGS_INTERNAL_STR_JOIN_INTERNAL_H_
+#define ABSL_STRINGS_INTERNAL_STR_JOIN_INTERNAL_H_
+
+#include <cstring>
+#include <iterator>
+#include <memory>
+#include <string>
+#include <type_traits>
+#include <utility>
+
+#include "absl/strings/internal/ostringstream.h"
+#include "absl/strings/internal/resize_uninitialized.h"
+#include "absl/strings/str_cat.h"
+
+namespace absl {
+namespace strings_internal {
+
+//
+// Formatter objects
+//
+// The following are implementation classes for standard Formatter objects. The
+// factory functions that users will call to create and use these formatters are
+// defined and documented in strings/join.h.
+//
+
+// The default formatter. Converts alpha-numeric types to strings.
+struct AlphaNumFormatterImpl {
+ // This template is needed in order to support passing in a dereferenced
+ // vector<bool>::iterator
+ template <typename T>
+ void operator()(std::string* out, const T& t) const {
+ StrAppend(out, AlphaNum(t));
+ }
+
+ void operator()(std::string* out, const AlphaNum& t) const {
+ StrAppend(out, t);
+ }
+};
+
+// A type that's used to overload the JoinAlgorithm() function (defined below)
+// for ranges that do not require additional formatting (e.g., a range of
+// strings).
+
+struct NoFormatter : public AlphaNumFormatterImpl {};
+
+// Formats types to strings using the << operator.
+class StreamFormatterImpl {
+ public:
+ // The method isn't const because it mutates state. Making it const will
+ // render StreamFormatterImpl thread-hostile.
+ template <typename T>
+ void operator()(std::string* out, const T& t) {
+ // The stream is created lazily to avoid paying the relatively high cost
+ // of its construction when joining an empty range.
+ if (strm_) {
+ strm_->clear(); // clear the bad, fail and eof bits in case they were set
+ strm_->str(out);
+ } else {
+ strm_.reset(new strings_internal::OStringStream(out));
+ }
+ *strm_ << t;
+ }
+
+ private:
+ std::unique_ptr<strings_internal::OStringStream> strm_;
+};
+
+// Formats a std::pair<>. The 'first' member is formatted using f1_ and the
+// 'second' member is formatted using f2_. sep_ is the separator.
+template <typename F1, typename F2>
+class PairFormatterImpl {
+ public:
+ PairFormatterImpl(F1 f1, absl::string_view sep, F2 f2)
+ : f1_(std::move(f1)), sep_(sep), f2_(std::move(f2)) {}
+
+ template <typename T>
+ void operator()(std::string* out, const T& p) {
+ f1_(out, p.first);
+ out->append(sep_);
+ f2_(out, p.second);
+ }
+
+ template <typename T>
+ void operator()(std::string* out, const T& p) const {
+ f1_(out, p.first);
+ out->append(sep_);
+ f2_(out, p.second);
+ }
+
+ private:
+ F1 f1_;
+ std::string sep_;
+ F2 f2_;
+};
+
+// Wraps another formatter and dereferences the argument to operator() then
+// passes the dereferenced argument to the wrapped formatter. This can be
+// useful, for example, to join a std::vector<int*>.
+template <typename Formatter>
+class DereferenceFormatterImpl {
+ public:
+ DereferenceFormatterImpl() : f_() {}
+ explicit DereferenceFormatterImpl(Formatter&& f)
+ : f_(std::forward<Formatter>(f)) {}
+
+ template <typename T>
+ void operator()(std::string* out, const T& t) {
+ f_(out, *t);
+ }
+
+ template <typename T>
+ void operator()(std::string* out, const T& t) const {
+ f_(out, *t);
+ }
+
+ private:
+ Formatter f_;
+};
+
+// DefaultFormatter<T> is a traits class that selects a default Formatter to use
+// for the given type T. The ::Type member names the Formatter to use. This is
+// used by the strings::Join() functions that do NOT take a Formatter argument,
+// in which case a default Formatter must be chosen.
+//
+// AlphaNumFormatterImpl is the default in the base template, followed by
+// specializations for other types.
+template <typename ValueType>
+struct DefaultFormatter {
+ typedef AlphaNumFormatterImpl Type;
+};
+template <>
+struct DefaultFormatter<const char*> {
+ typedef AlphaNumFormatterImpl Type;
+};
+template <>
+struct DefaultFormatter<char*> {
+ typedef AlphaNumFormatterImpl Type;
+};
+template <>
+struct DefaultFormatter<std::string> {
+ typedef NoFormatter Type;
+};
+template <>
+struct DefaultFormatter<absl::string_view> {
+ typedef NoFormatter Type;
+};
+template <typename ValueType>
+struct DefaultFormatter<ValueType*> {
+ typedef DereferenceFormatterImpl<typename DefaultFormatter<ValueType>::Type>
+ Type;
+};
+
+template <typename ValueType>
+struct DefaultFormatter<std::unique_ptr<ValueType>>
+ : public DefaultFormatter<ValueType*> {};
+
+//
+// JoinAlgorithm() functions
+//
+
+// The main joining algorithm. This simply joins the elements in the given
+// iterator range, each separated by the given separator, into an output string,
+// and formats each element using the provided Formatter object.
+template <typename Iterator, typename Formatter>
+std::string JoinAlgorithm(Iterator start, Iterator end, absl::string_view s,
+ Formatter&& f) {
+ std::string result;
+ absl::string_view sep("");
+ for (Iterator it = start; it != end; ++it) {
+ result.append(sep.data(), sep.size());
+ f(&result, *it);
+ sep = s;
+ }
+ return result;
+}
+
+// A joining algorithm that's optimized for a forward iterator range of
+// string-like objects that do not need any additional formatting. This is to
+// optimize the common case of joining, say, a std::vector<string> or a
+// std::vector<absl::string_view>.
+//
+// This is an overload of the previous JoinAlgorithm() function. Here the
+// Formatter argument is of type NoFormatter. Since NoFormatter is an internal
+// type, this overload is only invoked when strings::Join() is called with a
+// range of string-like objects (e.g., std::string, absl::string_view), and an
+// explicit Formatter argument was NOT specified.
+//
+// The optimization is that the needed space will be reserved in the output
+// string to avoid the need to resize while appending. To do this, the iterator
+// range will be traversed twice: once to calculate the total needed size, and
+// then again to copy the elements and delimiters to the output string.
+template <typename Iterator,
+ typename = typename std::enable_if<std::is_convertible<
+ typename std::iterator_traits<Iterator>::iterator_category,
+ std::forward_iterator_tag>::value>::type>
+std::string JoinAlgorithm(Iterator start, Iterator end, absl::string_view s,
+ NoFormatter) {
+ std::string result;
+ if (start != end) {
+ // Sums size
+ size_t result_size = start->size();
+ for (Iterator it = start; ++it != end;) {
+ result_size += s.size();
+ result_size += it->size();
+ }
+
+ if (result_size > 0) {
+ STLStringResizeUninitialized(&result, result_size);
+
+ // Joins strings
+ char* result_buf = &*result.begin();
+ memcpy(result_buf, start->data(), start->size());
+ result_buf += start->size();
+ for (Iterator it = start; ++it != end;) {
+ memcpy(result_buf, s.data(), s.size());
+ result_buf += s.size();
+ memcpy(result_buf, it->data(), it->size());
+ result_buf += it->size();
+ }
+ }
+ }
+
+ return result;
+}
+
+// JoinTupleLoop implements a loop over the elements of a std::tuple, which
+// are heterogeneous. The primary template matches the tuple interior case. It
+// continues the iteration after appending a separator (for nonzero indices)
+// and formatting an element of the tuple. The specialization for the I=N case
+// matches the end-of-tuple, and terminates the iteration.
+template <size_t I, size_t N>
+struct JoinTupleLoop {
+ template <typename Tup, typename Formatter>
+ void operator()(std::string* out, const Tup& tup, absl::string_view sep,
+ Formatter&& fmt) {
+ if (I > 0) out->append(sep.data(), sep.size());
+ fmt(out, std::get<I>(tup));
+ JoinTupleLoop<I + 1, N>()(out, tup, sep, fmt);
+ }
+};
+template <size_t N>
+struct JoinTupleLoop<N, N> {
+ template <typename Tup, typename Formatter>
+ void operator()(std::string*, const Tup&, absl::string_view, Formatter&&) {}
+};
+
+template <typename... T, typename Formatter>
+std::string JoinAlgorithm(const std::tuple<T...>& tup, absl::string_view sep,
+ Formatter&& fmt) {
+ std::string result;
+ JoinTupleLoop<0, sizeof...(T)>()(&result, tup, sep, fmt);
+ return result;
+}
+
+template <typename Iterator>
+std::string JoinRange(Iterator first, Iterator last,
+ absl::string_view separator) {
+ // No formatter was explicitly given, so a default must be chosen.
+ typedef typename std::iterator_traits<Iterator>::value_type ValueType;
+ typedef typename DefaultFormatter<ValueType>::Type Formatter;
+ return JoinAlgorithm(first, last, separator, Formatter());
+}
+
+template <typename Range, typename Formatter>
+std::string JoinRange(const Range& range, absl::string_view separator,
+ Formatter&& fmt) {
+ using std::begin;
+ using std::end;
+ return JoinAlgorithm(begin(range), end(range), separator, fmt);
+}
+
+template <typename Range>
+std::string JoinRange(const Range& range, absl::string_view separator) {
+ using std::begin;
+ using std::end;
+ return JoinRange(begin(range), end(range), separator);
+}
+
+} // namespace strings_internal
+} // namespace absl
+
+#endif // ABSL_STRINGS_INTERNAL_STR_JOIN_INTERNAL_H_
diff --git a/absl/strings/internal/str_split_internal.h b/absl/strings/internal/str_split_internal.h
new file mode 100644
index 0000000..52f6222
--- /dev/null
+++ b/absl/strings/internal/str_split_internal.h
@@ -0,0 +1,453 @@
+// Copyright 2017 The Abseil Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+
+// This file declares INTERNAL parts of the Split API that are inline/templated
+// or otherwise need to be available at compile time. The main abstractions
+// defined in here are
+//
+// - ConvertibleToStringView
+// - SplitIterator<>
+// - Splitter<>
+//
+// DO NOT INCLUDE THIS FILE DIRECTLY. Use this file by including
+// absl/strings/str_split.h.
+//
+// IWYU pragma: private, include "absl/strings/str_split.h"
+
+#ifndef ABSL_STRINGS_INTERNAL_STR_SPLIT_INTERNAL_H_
+#define ABSL_STRINGS_INTERNAL_STR_SPLIT_INTERNAL_H_
+
+#include <array>
+#include <initializer_list>
+#include <iterator>
+#include <map>
+#include <type_traits>
+#include <utility>
+#include <vector>
+
+#include "absl/base/macros.h"
+#include "absl/base/port.h"
+#include "absl/meta/type_traits.h"
+#include "absl/strings/string_view.h"
+
+#ifdef _GLIBCXX_DEBUG
+#include "absl/strings/internal/stl_type_traits.h"
+#endif // _GLIBCXX_DEBUG
+
+namespace absl {
+namespace strings_internal {
+
+// This class is implicitly constructible from everything that absl::string_view
+// is implicitly constructible from. If it's constructed from a temporary
+// string, the data is moved into a data member so its lifetime matches that of
+// the ConvertibleToStringView instance.
+class ConvertibleToStringView {
+ public:
+ ConvertibleToStringView(const char* s) // NOLINT(runtime/explicit)
+ : value_(s) {}
+ ConvertibleToStringView(char* s) : value_(s) {} // NOLINT(runtime/explicit)
+ ConvertibleToStringView(absl::string_view s) // NOLINT(runtime/explicit)
+ : value_(s) {}
+ ConvertibleToStringView(const std::string& s) // NOLINT(runtime/explicit)
+ : value_(s) {}
+
+ // Matches rvalue strings and moves their data to a member.
+ConvertibleToStringView(std::string&& s) // NOLINT(runtime/explicit)
+ : copy_(std::move(s)), value_(copy_) {}
+
+ ConvertibleToStringView(const ConvertibleToStringView& other)
+ : copy_(other.copy_),
+ value_(other.IsSelfReferential() ? copy_ : other.value_) {}
+
+ ConvertibleToStringView(ConvertibleToStringView&& other) {
+ StealMembers(std::move(other));
+ }
+
+ ConvertibleToStringView& operator=(ConvertibleToStringView other) {
+ StealMembers(std::move(other));
+ return *this;
+ }
+
+ absl::string_view value() const { return value_; }
+
+ private:
+ // Returns true if ctsp's value refers to its internal copy_ member.
+ bool IsSelfReferential() const { return value_.data() == copy_.data(); }
+
+ void StealMembers(ConvertibleToStringView&& other) {
+ if (other.IsSelfReferential()) {
+ copy_ = std::move(other.copy_);
+ value_ = copy_;
+ other.value_ = other.copy_;
+ } else {
+ value_ = other.value_;
+ }
+ }
+
+ // Holds the data moved from temporary std::string arguments. Declared first
+ // so that 'value' can refer to 'copy_'.
+ std::string copy_;
+ absl::string_view value_;
+};
+
+// An iterator that enumerates the parts of a string from a Splitter. The text
+// to be split, the Delimiter, and the Predicate are all taken from the given
+// Splitter object. Iterators may only be compared if they refer to the same
+// Splitter instance.
+//
+// This class is NOT part of the public splitting API.
+template <typename Splitter>
+class SplitIterator {
+ public:
+ using iterator_category = std::input_iterator_tag;
+ using value_type = absl::string_view;
+ using difference_type = ptrdiff_t;
+ using pointer = const value_type*;
+ using reference = const value_type&;
+
+ enum State { kInitState, kLastState, kEndState };
+ SplitIterator(State state, const Splitter* splitter)
+ : pos_(0),
+ state_(state),
+ splitter_(splitter),
+ delimiter_(splitter->delimiter()),
+ predicate_(splitter->predicate()) {
+ // Hack to maintain backward compatibility. This one block makes it so an
+ // empty absl::string_view whose .data() happens to be nullptr behaves
+ // *differently* from an otherwise empty absl::string_view whose .data() is
+ // not nullptr. This is an undesirable difference in general, but this
+ // behavior is maintained to avoid breaking existing code that happens to
+ // depend on this old behavior/bug. Perhaps it will be fixed one day. The
+ // difference in behavior is as follows:
+ // Split(absl::string_view(""), '-'); // {""}
+ // Split(absl::string_view(), '-'); // {}
+ if (splitter_->text().data() == nullptr) {
+ state_ = kEndState;
+ pos_ = splitter_->text().size();
+ return;
+ }
+
+ if (state_ == kEndState) {
+ pos_ = splitter_->text().size();
+ } else {
+ ++(*this);
+ }
+ }
+
+ bool at_end() const { return state_ == kEndState; }
+
+ reference operator*() const { return curr_; }
+ pointer operator->() const { return &curr_; }
+
+ SplitIterator& operator++() {
+ do {
+ if (state_ == kLastState) {
+ state_ = kEndState;
+ return *this;
+ }
+ const absl::string_view text = splitter_->text();
+ const absl::string_view d = delimiter_.Find(text, pos_);
+ if (d.data() == text.data() + text.size()) state_ = kLastState;
+ curr_ = text.substr(pos_, d.data() - (text.data() + pos_));
+ pos_ += curr_.size() + d.size();
+ } while (!predicate_(curr_));
+ return *this;
+ }
+
+ SplitIterator operator++(int) {
+ SplitIterator old(*this);
+ ++(*this);
+ return old;
+ }
+
+ friend bool operator==(const SplitIterator& a, const SplitIterator& b) {
+ return a.state_ == b.state_ && a.pos_ == b.pos_;
+ }
+
+ friend bool operator!=(const SplitIterator& a, const SplitIterator& b) {
+ return !(a == b);
+ }
+
+ private:
+ size_t pos_;
+ State state_;
+ absl::string_view curr_;
+ const Splitter* splitter_;
+ typename Splitter::DelimiterType delimiter_;
+ typename Splitter::PredicateType predicate_;
+};
+
+// HasMappedType<T>::value is true iff there exists a type T::mapped_type.
+template <typename T, typename = void>
+struct HasMappedType : std::false_type {};
+template <typename T>
+struct HasMappedType<T, absl::void_t<typename T::mapped_type>>
+ : std::true_type {};
+
+// HasValueType<T>::value is true iff there exists a type T::value_type.
+template <typename T, typename = void>
+struct HasValueType : std::false_type {};
+template <typename T>
+struct HasValueType<T, absl::void_t<typename T::value_type>> : std::true_type {
+};
+
+// HasConstIterator<T>::value is true iff there exists a type T::const_iterator.
+template <typename T, typename = void>
+struct HasConstIterator : std::false_type {};
+template <typename T>
+struct HasConstIterator<T, absl::void_t<typename T::const_iterator>>
+ : std::true_type {};
+
+// IsInitializerList<T>::value is true iff T is an std::initializer_list. More
+// details below in Splitter<> where this is used.
+std::false_type IsInitializerListDispatch(...); // default: No
+template <typename T>
+std::true_type IsInitializerListDispatch(std::initializer_list<T>*);
+template <typename T>
+struct IsInitializerList
+ : decltype(IsInitializerListDispatch(static_cast<T*>(nullptr))) {};
+
+// A SplitterIsConvertibleTo<C>::type alias exists iff the specified condition
+// is true for type 'C'.
+//
+// Restricts conversion to container-like types (by testing for the presence of
+// a const_iterator member type) and also to disable conversion to an
+// std::initializer_list (which also has a const_iterator). Otherwise, code
+// compiled in C++11 will get an error due to ambiguous conversion paths (in
+// C++11 std::vector<T>::operator= is overloaded to take either a std::vector<T>
+// or an std::initializer_list<T>).
+
+template <typename C, bool has_value_type, bool has_mapped_type>
+struct SplitterIsConvertibleToImpl : std::false_type {};
+
+template <typename C>
+struct SplitterIsConvertibleToImpl<C, true, false>
+ : std::is_constructible<typename C::value_type, absl::string_view> {};
+
+template <typename C>
+struct SplitterIsConvertibleToImpl<C, true, true>
+ : absl::conjunction<
+ std::is_constructible<typename C::key_type, absl::string_view>,
+ std::is_constructible<typename C::mapped_type, absl::string_view>> {};
+
+template <typename C>
+struct SplitterIsConvertibleTo
+ : SplitterIsConvertibleToImpl<
+ C,
+#ifdef _GLIBCXX_DEBUG
+ !IsStrictlyBaseOfAndConvertibleToSTLContainer<C>::value &&
+#endif // _GLIBCXX_DEBUG
+ !IsInitializerList<
+ typename std::remove_reference<C>::type>::value &&
+ HasValueType<C>::value && HasConstIterator<C>::value,
+ HasMappedType<C>::value> {
+};
+
+// This class implements the range that is returned by absl::StrSplit(). This
+// class has templated conversion operators that allow it to be implicitly
+// converted to a variety of types that the caller may have specified on the
+// left-hand side of an assignment.
+//
+// The main interface for interacting with this class is through its implicit
+// conversion operators. However, this class may also be used like a container
+// in that it has .begin() and .end() member functions. It may also be used
+// within a range-for loop.
+//
+// Output containers can be collections of any type that is constructible from
+// an absl::string_view.
+//
+// An Predicate functor may be supplied. This predicate will be used to filter
+// the split strings: only strings for which the predicate returns true will be
+// kept. A Predicate object is any unary functor that takes an absl::string_view
+// and returns bool.
+template <typename Delimiter, typename Predicate>
+class Splitter {
+ public:
+ using DelimiterType = Delimiter;
+ using PredicateType = Predicate;
+ using const_iterator = strings_internal::SplitIterator<Splitter>;
+ using value_type = typename std::iterator_traits<const_iterator>::value_type;
+
+ Splitter(ConvertibleToStringView input_text, Delimiter d, Predicate p)
+ : text_(std::move(input_text)),
+ delimiter_(std::move(d)),
+ predicate_(std::move(p)) {}
+
+ absl::string_view text() const { return text_.value(); }
+ const Delimiter& delimiter() const { return delimiter_; }
+ const Predicate& predicate() const { return predicate_; }
+
+ // Range functions that iterate the split substrings as absl::string_view
+ // objects. These methods enable a Splitter to be used in a range-based for
+ // loop.
+ const_iterator begin() const { return {const_iterator::kInitState, this}; }
+ const_iterator end() const { return {const_iterator::kEndState, this}; }
+
+ // An implicit conversion operator that is restricted to only those containers
+ // that the splitter is convertible to.
+ template <typename Container,
+ typename = typename std::enable_if<
+ SplitterIsConvertibleTo<Container>::value>::type>
+ operator Container() const { // NOLINT(runtime/explicit)
+ return ConvertToContainer<Container, typename Container::value_type,
+ HasMappedType<Container>::value>()(*this);
+ }
+
+ // Returns a pair with its .first and .second members set to the first two
+ // strings returned by the begin() iterator. Either/both of .first and .second
+ // will be constructed with empty strings if the iterator doesn't have a
+ // corresponding value.
+ template <typename First, typename Second>
+ operator std::pair<First, Second>() const { // NOLINT(runtime/explicit)
+ absl::string_view first, second;
+ auto it = begin();
+ if (it != end()) {
+ first = *it;
+ if (++it != end()) {
+ second = *it;
+ }
+ }
+ return {First(first), Second(second)};
+ }
+
+ private:
+ // ConvertToContainer is a functor converting a Splitter to the requested
+ // Container of ValueType. It is specialized below to optimize splitting to
+ // certain combinations of Container and ValueType.
+ //
+ // This base template handles the generic case of storing the split results in
+ // the requested non-map-like container and converting the split substrings to
+ // the requested type.
+ template <typename Container, typename ValueType, bool is_map = false>
+ struct ConvertToContainer {
+ Container operator()(const Splitter& splitter) const {
+ Container c;
+ auto it = std::inserter(c, c.end());
+ for (const auto sp : splitter) {
+ *it++ = ValueType(sp);
+ }
+ return c;
+ }
+ };
+
+ // Partial specialization for a std::vector<absl::string_view>.
+ //
+ // Optimized for the common case of splitting to a
+ // std::vector<absl::string_view>. In this case we first split the results to
+ // a small array of absl::string_view on the stack, to reduce reallocations.
+ template <typename A>
+ struct ConvertToContainer<std::vector<absl::string_view, A>,
+ absl::string_view, false> {
+ std::vector<absl::string_view, A> operator()(
+ const Splitter& splitter) const {
+ struct raw_view {
+ const char* data;
+ size_t size;
+ operator absl::string_view() const { // NOLINT(runtime/explicit)
+ return {data, size};
+ }
+ };
+ std::vector<absl::string_view, A> v;
+ std::array<raw_view, 16> ar;
+ for (auto it = splitter.begin(); !it.at_end();) {
+ size_t index = 0;
+ do {
+ ar[index].data = it->data();
+ ar[index].size = it->size();
+ ++it;
+ } while (++index != ar.size() && !it.at_end());
+ v.insert(v.end(), ar.begin(), ar.begin() + index);
+ }
+ return v;
+ }
+ };
+
+ // Partial specialization for a std::vector<std::string>.
+ //
+ // Optimized for the common case of splitting to a std::vector<std::string>.
+ // In this case we first split the results to a std::vector<absl::string_view>
+ // so the returned std::vector<std::string> can have space reserved to avoid
+ // std::string moves.
+ template <typename A>
+ struct ConvertToContainer<std::vector<std::string, A>, std::string, false> {
+ std::vector<std::string, A> operator()(const Splitter& splitter) const {
+ const std::vector<absl::string_view> v = splitter;
+ return std::vector<std::string, A>(v.begin(), v.end());
+ }
+ };
+
+ // Partial specialization for containers of pairs (e.g., maps).
+ //
+ // The algorithm is to insert a new pair into the map for each even-numbered
+ // item, with the even-numbered item as the key with a default-constructed
+ // value. Each odd-numbered item will then be assigned to the last pair's
+ // value.
+ template <typename Container, typename First, typename Second>
+ struct ConvertToContainer<Container, std::pair<const First, Second>, true> {
+ Container operator()(const Splitter& splitter) const {
+ Container m;
+ typename Container::iterator it;
+ bool insert = true;
+ for (const auto sp : splitter) {
+ if (insert) {
+ it = Inserter<Container>::Insert(&m, First(sp), Second());
+ } else {
+ it->second = Second(sp);
+ }
+ insert = !insert;
+ }
+ return m;
+ }
+
+ // Inserts the key and value into the given map, returning an iterator to
+ // the inserted item. Specialized for std::map and std::multimap to use
+ // emplace() and adapt emplace()'s return value.
+ template <typename Map>
+ struct Inserter {
+ using M = Map;
+ template <typename... Args>
+ static typename M::iterator Insert(M* m, Args&&... args) {
+ return m->insert(std::make_pair(std::forward<Args>(args)...)).first;
+ }
+ };
+
+ template <typename... Ts>
+ struct Inserter<std::map<Ts...>> {
+ using M = std::map<Ts...>;
+ template <typename... Args>
+ static typename M::iterator Insert(M* m, Args&&... args) {
+ return m->emplace(std::make_pair(std::forward<Args>(args)...)).first;
+ }
+ };
+
+ template <typename... Ts>
+ struct Inserter<std::multimap<Ts...>> {
+ using M = std::multimap<Ts...>;
+ template <typename... Args>
+ static typename M::iterator Insert(M* m, Args&&... args) {
+ return m->emplace(std::make_pair(std::forward<Args>(args)...));
+ }
+ };
+ };
+
+ ConvertibleToStringView text_;
+ Delimiter delimiter_;
+ Predicate predicate_;
+};
+
+} // namespace strings_internal
+} // namespace absl
+
+#endif // ABSL_STRINGS_INTERNAL_STR_SPLIT_INTERNAL_H_
diff --git a/absl/strings/internal/utf8.cc b/absl/strings/internal/utf8.cc
new file mode 100644
index 0000000..82d36c2
--- /dev/null
+++ b/absl/strings/internal/utf8.cc
@@ -0,0 +1,51 @@
+// Copyright 2017 The Abseil Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// UTF8 utilities, implemented to reduce dependencies.
+
+#include "absl/strings/internal/utf8.h"
+
+namespace absl {
+namespace strings_internal {
+
+size_t EncodeUTF8Char(char *buffer, char32_t utf8_char) {
+ if (utf8_char <= 0x7F) {
+ *buffer = static_cast<char>(utf8_char);
+ return 1;
+ } else if (utf8_char <= 0x7FF) {
+ buffer[1] = 0x80 | (utf8_char & 0x3F);
+ utf8_char >>= 6;
+ buffer[0] = 0xC0 | utf8_char;
+ return 2;
+ } else if (utf8_char <= 0xFFFF) {
+ buffer[2] = 0x80 | (utf8_char & 0x3F);
+ utf8_char >>= 6;
+ buffer[1] = 0x80 | (utf8_char & 0x3F);
+ utf8_char >>= 6;
+ buffer[0] = 0xE0 | utf8_char;
+ return 3;
+ } else {
+ buffer[3] = 0x80 | (utf8_char & 0x3F);
+ utf8_char >>= 6;
+ buffer[2] = 0x80 | (utf8_char & 0x3F);
+ utf8_char >>= 6;
+ buffer[1] = 0x80 | (utf8_char & 0x3F);
+ utf8_char >>= 6;
+ buffer[0] = 0xF0 | utf8_char;
+ return 4;
+ }
+}
+
+} // namespace strings_internal
+} // namespace absl
diff --git a/absl/strings/internal/utf8.h b/absl/strings/internal/utf8.h
new file mode 100644
index 0000000..0423630
--- /dev/null
+++ b/absl/strings/internal/utf8.h
@@ -0,0 +1,46 @@
+// Copyright 2017 The Abseil Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+// UTF8 utilities, implemented to reduce dependencies.
+
+#ifndef ABSL_STRINGS_INTERNAL_UTF8_H_
+#define ABSL_STRINGS_INTERNAL_UTF8_H_
+
+#include <cstddef>
+#include <cstdint>
+
+namespace absl {
+namespace strings_internal {
+
+// For Unicode code points 0 through 0x10FFFF, EncodeUTF8Char writes
+// out the UTF-8 encoding into buffer, and returns the number of chars
+// it wrote.
+//
+// As described in https://tools.ietf.org/html/rfc3629#section-3 , the encodings
+// are:
+// 00 - 7F : 0xxxxxxx
+// 80 - 7FF : 110xxxxx 10xxxxxx
+// 800 - FFFF : 1110xxxx 10xxxxxx 10xxxxxx
+// 10000 - 10FFFF : 11110xxx 10xxxxxx 10xxxxxx 10xxxxxx
+//
+// Values greater than 0x10FFFF are not supported and may or may not write
+// characters into buffer, however never will more than kMaxEncodedUTF8Size
+// bytes be written, regardless of the value of utf8_char.
+enum { kMaxEncodedUTF8Size = 4 };
+size_t EncodeUTF8Char(char *buffer, char32_t utf8_char);
+
+} // namespace strings_internal
+} // namespace absl
+
+#endif // ABSL_STRINGS_INTERNAL_UTF8_H_
diff --git a/absl/strings/internal/utf8_test.cc b/absl/strings/internal/utf8_test.cc
new file mode 100644
index 0000000..88dd503
--- /dev/null
+++ b/absl/strings/internal/utf8_test.cc
@@ -0,0 +1,66 @@
+// Copyright 2017 The Abseil Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include "absl/strings/internal/utf8.h"
+
+#include <cstdint>
+#include <utility>
+
+#include "gtest/gtest.h"
+#include "absl/base/port.h"
+
+namespace {
+
+#if !defined(__cpp_char8_t)
+#if defined(__clang__)
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Wc++2a-compat"
+#endif
+TEST(EncodeUTF8Char, BasicFunction) {
+ std::pair<char32_t, std::string> tests[] = {{0x0030, u8"\u0030"},
+ {0x00A3, u8"\u00A3"},
+ {0x00010000, u8"\U00010000"},
+ {0x0000FFFF, u8"\U0000FFFF"},
+ {0x0010FFFD, u8"\U0010FFFD"}};
+ for (auto &test : tests) {
+ char buf0[7] = {'\x00', '\x00', '\x00', '\x00', '\x00', '\x00', '\x00'};
+ char buf1[7] = {'\xFF', '\xFF', '\xFF', '\xFF', '\xFF', '\xFF', '\xFF'};
+ char *buf0_written =
+ &buf0[absl::strings_internal::EncodeUTF8Char(buf0, test.first)];
+ char *buf1_written =
+ &buf1[absl::strings_internal::EncodeUTF8Char(buf1, test.first)];
+ int apparent_length = 7;
+ while (buf0[apparent_length - 1] == '\x00' &&
+ buf1[apparent_length - 1] == '\xFF') {
+ if (--apparent_length == 0) break;
+ }
+ EXPECT_EQ(apparent_length, buf0_written - buf0);
+ EXPECT_EQ(apparent_length, buf1_written - buf1);
+ EXPECT_EQ(apparent_length, test.second.length());
+ EXPECT_EQ(std::string(buf0, apparent_length), test.second);
+ EXPECT_EQ(std::string(buf1, apparent_length), test.second);
+ }
+ char buf[32] = "Don't Tread On Me";
+ EXPECT_LE(absl::strings_internal::EncodeUTF8Char(buf, 0x00110000),
+ absl::strings_internal::kMaxEncodedUTF8Size);
+ char buf2[32] = "Negative is invalid but sane";
+ EXPECT_LE(absl::strings_internal::EncodeUTF8Char(buf2, -1),
+ absl::strings_internal::kMaxEncodedUTF8Size);
+}
+#if defined(__clang__)
+#pragma clang diagnostic pop
+#endif
+#endif // !defined(__cpp_char8_t)
+
+} // namespace