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Austin Schuhe89fa2d2019-08-14 20:24:23 -07001/*
2 * Copyright 2014 Google Inc. All rights reserved.
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17#ifndef FLATBUFFERS_UTIL_H_
18#define FLATBUFFERS_UTIL_H_
19
Austin Schuhe89fa2d2019-08-14 20:24:23 -070020#include <errno.h>
21
Austin Schuh272c6132020-11-14 16:37:52 -080022#include "flatbuffers/base.h"
23#include "flatbuffers/stl_emulation.h"
24
Austin Schuhe89fa2d2019-08-14 20:24:23 -070025#ifndef FLATBUFFERS_PREFER_PRINTF
26# include <sstream>
27#else // FLATBUFFERS_PREFER_PRINTF
28# include <float.h>
29# include <stdio.h>
30#endif // FLATBUFFERS_PREFER_PRINTF
31
32#include <iomanip>
33#include <string>
34
35namespace flatbuffers {
36
37// @locale-independent functions for ASCII characters set.
38
39// Fast checking that character lies in closed range: [a <= x <= b]
40// using one compare (conditional branch) operator.
41inline bool check_ascii_range(char x, char a, char b) {
42 FLATBUFFERS_ASSERT(a <= b);
43 // (Hacker's Delight): `a <= x <= b` <=> `(x-a) <={u} (b-a)`.
44 // The x, a, b will be promoted to int and subtracted without overflow.
45 return static_cast<unsigned int>(x - a) <= static_cast<unsigned int>(b - a);
46}
47
48// Case-insensitive isalpha
49inline bool is_alpha(char c) {
50 // ASCII only: alpha to upper case => reset bit 0x20 (~0x20 = 0xDF).
51 return check_ascii_range(c & 0xDF, 'a' & 0xDF, 'z' & 0xDF);
52}
53
54// Check (case-insensitive) that `c` is equal to alpha.
55inline bool is_alpha_char(char c, char alpha) {
56 FLATBUFFERS_ASSERT(is_alpha(alpha));
57 // ASCII only: alpha to upper case => reset bit 0x20 (~0x20 = 0xDF).
58 return ((c & 0xDF) == (alpha & 0xDF));
59}
60
61// https://en.cppreference.com/w/cpp/string/byte/isxdigit
62// isdigit and isxdigit are the only standard narrow character classification
63// functions that are not affected by the currently installed C locale. although
64// some implementations (e.g. Microsoft in 1252 codepage) may classify
65// additional single-byte characters as digits.
66inline bool is_digit(char c) { return check_ascii_range(c, '0', '9'); }
67
68inline bool is_xdigit(char c) {
69 // Replace by look-up table.
70 return is_digit(c) || check_ascii_range(c & 0xDF, 'a' & 0xDF, 'f' & 0xDF);
71}
72
73// Case-insensitive isalnum
74inline bool is_alnum(char c) { return is_alpha(c) || is_digit(c); }
75
Austin Schuh272c6132020-11-14 16:37:52 -080076inline char CharToUpper(char c) {
77 return static_cast<char>(::toupper(static_cast<unsigned char>(c)));
78}
79
80inline char CharToLower(char c) {
81 return static_cast<char>(::tolower(static_cast<unsigned char>(c)));
82}
83
Austin Schuhe89fa2d2019-08-14 20:24:23 -070084// @end-locale-independent functions for ASCII character set
85
86#ifdef FLATBUFFERS_PREFER_PRINTF
87template<typename T> size_t IntToDigitCount(T t) {
88 size_t digit_count = 0;
89 // Count the sign for negative numbers
90 if (t < 0) digit_count++;
91 // Count a single 0 left of the dot for fractional numbers
92 if (-1 < t && t < 1) digit_count++;
93 // Count digits until fractional part
94 T eps = std::numeric_limits<float>::epsilon();
95 while (t <= (-1 + eps) || (1 - eps) <= t) {
96 t /= 10;
97 digit_count++;
98 }
99 return digit_count;
100}
101
102template<typename T> size_t NumToStringWidth(T t, int precision = 0) {
103 size_t string_width = IntToDigitCount(t);
104 // Count the dot for floating point numbers
105 if (precision) string_width += (precision + 1);
106 return string_width;
107}
108
109template<typename T>
110std::string NumToStringImplWrapper(T t, const char *fmt, int precision = 0) {
111 size_t string_width = NumToStringWidth(t, precision);
112 std::string s(string_width, 0x00);
113 // Allow snprintf to use std::string trailing null to detect buffer overflow
114 snprintf(const_cast<char *>(s.data()), (s.size() + 1), fmt, string_width, t);
115 return s;
116}
117#endif // FLATBUFFERS_PREFER_PRINTF
118
119// Convert an integer or floating point value to a string.
120// In contrast to std::stringstream, "char" values are
121// converted to a string of digits, and we don't use scientific notation.
122template<typename T> std::string NumToString(T t) {
123 // clang-format off
124
125 #ifndef FLATBUFFERS_PREFER_PRINTF
126 std::stringstream ss;
127 ss << t;
128 return ss.str();
129 #else // FLATBUFFERS_PREFER_PRINTF
130 auto v = static_cast<long long>(t);
131 return NumToStringImplWrapper(v, "%.*lld");
132 #endif // FLATBUFFERS_PREFER_PRINTF
133 // clang-format on
134}
135// Avoid char types used as character data.
136template<> inline std::string NumToString<signed char>(signed char t) {
137 return NumToString(static_cast<int>(t));
138}
139template<> inline std::string NumToString<unsigned char>(unsigned char t) {
140 return NumToString(static_cast<int>(t));
141}
142template<> inline std::string NumToString<char>(char t) {
143 return NumToString(static_cast<int>(t));
144}
145#if defined(FLATBUFFERS_CPP98_STL)
146template<> inline std::string NumToString<long long>(long long t) {
147 char buf[21]; // (log((1 << 63) - 1) / log(10)) + 2
148 snprintf(buf, sizeof(buf), "%lld", t);
149 return std::string(buf);
150}
151
152template<>
153inline std::string NumToString<unsigned long long>(unsigned long long t) {
154 char buf[22]; // (log((1 << 63) - 1) / log(10)) + 1
155 snprintf(buf, sizeof(buf), "%llu", t);
156 return std::string(buf);
157}
158#endif // defined(FLATBUFFERS_CPP98_STL)
159
160// Special versions for floats/doubles.
161template<typename T> std::string FloatToString(T t, int precision) {
162 // clang-format off
163
164 #ifndef FLATBUFFERS_PREFER_PRINTF
165 // to_string() prints different numbers of digits for floats depending on
166 // platform and isn't available on Android, so we use stringstream
167 std::stringstream ss;
168 // Use std::fixed to suppress scientific notation.
169 ss << std::fixed;
170 // Default precision is 6, we want that to be higher for doubles.
171 ss << std::setprecision(precision);
172 ss << t;
173 auto s = ss.str();
174 #else // FLATBUFFERS_PREFER_PRINTF
175 auto v = static_cast<double>(t);
176 auto s = NumToStringImplWrapper(v, "%0.*f", precision);
177 #endif // FLATBUFFERS_PREFER_PRINTF
178 // clang-format on
179 // Sadly, std::fixed turns "1" into "1.00000", so here we undo that.
180 auto p = s.find_last_not_of('0');
181 if (p != std::string::npos) {
182 // Strip trailing zeroes. If it is a whole number, keep one zero.
183 s.resize(p + (s[p] == '.' ? 2 : 1));
184 }
185 return s;
186}
187
188template<> inline std::string NumToString<double>(double t) {
189 return FloatToString(t, 12);
190}
191template<> inline std::string NumToString<float>(float t) {
192 return FloatToString(t, 6);
193}
194
195// Convert an integer value to a hexadecimal string.
196// The returned string length is always xdigits long, prefixed by 0 digits.
197// For example, IntToStringHex(0x23, 8) returns the string "00000023".
198inline std::string IntToStringHex(int i, int xdigits) {
199 FLATBUFFERS_ASSERT(i >= 0);
200 // clang-format off
201
202 #ifndef FLATBUFFERS_PREFER_PRINTF
203 std::stringstream ss;
204 ss << std::setw(xdigits) << std::setfill('0') << std::hex << std::uppercase
205 << i;
206 return ss.str();
207 #else // FLATBUFFERS_PREFER_PRINTF
208 return NumToStringImplWrapper(i, "%.*X", xdigits);
209 #endif // FLATBUFFERS_PREFER_PRINTF
210 // clang-format on
211}
212
213// clang-format off
214// Use locale independent functions {strtod_l, strtof_l, strtoll_l, strtoull_l}.
215#if defined(FLATBUFFERS_LOCALE_INDEPENDENT) && (FLATBUFFERS_LOCALE_INDEPENDENT > 0)
216 class ClassicLocale {
217 #ifdef _MSC_VER
218 typedef _locale_t locale_type;
219 #else
220 typedef locale_t locale_type; // POSIX.1-2008 locale_t type
221 #endif
222 ClassicLocale();
223 ~ClassicLocale();
224 locale_type locale_;
225 static ClassicLocale instance_;
226 public:
227 static locale_type Get() { return instance_.locale_; }
228 };
229
230 #ifdef _MSC_VER
231 #define __strtoull_impl(s, pe, b) _strtoui64_l(s, pe, b, ClassicLocale::Get())
232 #define __strtoll_impl(s, pe, b) _strtoi64_l(s, pe, b, ClassicLocale::Get())
233 #define __strtod_impl(s, pe) _strtod_l(s, pe, ClassicLocale::Get())
234 #define __strtof_impl(s, pe) _strtof_l(s, pe, ClassicLocale::Get())
235 #else
236 #define __strtoull_impl(s, pe, b) strtoull_l(s, pe, b, ClassicLocale::Get())
237 #define __strtoll_impl(s, pe, b) strtoll_l(s, pe, b, ClassicLocale::Get())
238 #define __strtod_impl(s, pe) strtod_l(s, pe, ClassicLocale::Get())
239 #define __strtof_impl(s, pe) strtof_l(s, pe, ClassicLocale::Get())
240 #endif
241#else
242 #define __strtod_impl(s, pe) strtod(s, pe)
243 #define __strtof_impl(s, pe) static_cast<float>(strtod(s, pe))
244 #ifdef _MSC_VER
245 #define __strtoull_impl(s, pe, b) _strtoui64(s, pe, b)
246 #define __strtoll_impl(s, pe, b) _strtoi64(s, pe, b)
247 #else
248 #define __strtoull_impl(s, pe, b) strtoull(s, pe, b)
249 #define __strtoll_impl(s, pe, b) strtoll(s, pe, b)
250 #endif
251#endif
252
253inline void strtoval_impl(int64_t *val, const char *str, char **endptr,
254 int base) {
255 *val = __strtoll_impl(str, endptr, base);
256}
257
258inline void strtoval_impl(uint64_t *val, const char *str, char **endptr,
259 int base) {
260 *val = __strtoull_impl(str, endptr, base);
261}
262
263inline void strtoval_impl(double *val, const char *str, char **endptr) {
264 *val = __strtod_impl(str, endptr);
265}
266
267// UBSAN: double to float is safe if numeric_limits<float>::is_iec559 is true.
268__supress_ubsan__("float-cast-overflow")
269inline void strtoval_impl(float *val, const char *str, char **endptr) {
270 *val = __strtof_impl(str, endptr);
271}
272#undef __strtoull_impl
273#undef __strtoll_impl
274#undef __strtod_impl
275#undef __strtof_impl
276// clang-format on
277
278// Adaptor for strtoull()/strtoll().
279// Flatbuffers accepts numbers with any count of leading zeros (-009 is -9),
280// while strtoll with base=0 interprets first leading zero as octal prefix.
281// In future, it is possible to add prefixed 0b0101.
282// 1) Checks errno code for overflow condition (out of range).
283// 2) If base <= 0, function try to detect base of number by prefix.
284//
285// Return value (like strtoull and strtoll, but reject partial result):
286// - If successful, an integer value corresponding to the str is returned.
287// - If full string conversion can't be performed, 0 is returned.
288// - If the converted value falls out of range of corresponding return type, a
289// range error occurs. In this case value MAX(T)/MIN(T) is returned.
290template<typename T>
291inline bool StringToIntegerImpl(T *val, const char *const str,
292 const int base = 0,
293 const bool check_errno = true) {
294 // T is int64_t or uint64_T
295 FLATBUFFERS_ASSERT(str);
296 if (base <= 0) {
297 auto s = str;
298 while (*s && !is_digit(*s)) s++;
299 if (s[0] == '0' && is_alpha_char(s[1], 'X'))
300 return StringToIntegerImpl(val, str, 16, check_errno);
301 // if a prefix not match, try base=10
302 return StringToIntegerImpl(val, str, 10, check_errno);
303 } else {
304 if (check_errno) errno = 0; // clear thread-local errno
305 auto endptr = str;
306 strtoval_impl(val, str, const_cast<char **>(&endptr), base);
307 if ((*endptr != '\0') || (endptr == str)) {
308 *val = 0; // erase partial result
309 return false; // invalid string
310 }
311 // errno is out-of-range, return MAX/MIN
312 if (check_errno && errno) return false;
313 return true;
314 }
315}
316
317template<typename T>
318inline bool StringToFloatImpl(T *val, const char *const str) {
319 // Type T must be either float or double.
320 FLATBUFFERS_ASSERT(str && val);
321 auto end = str;
322 strtoval_impl(val, str, const_cast<char **>(&end));
323 auto done = (end != str) && (*end == '\0');
324 if (!done) *val = 0; // erase partial result
325 return done;
326}
327
328// Convert a string to an instance of T.
329// Return value (matched with StringToInteger64Impl and strtod):
330// - If successful, a numeric value corresponding to the str is returned.
331// - If full string conversion can't be performed, 0 is returned.
332// - If the converted value falls out of range of corresponding return type, a
333// range error occurs. In this case value MAX(T)/MIN(T) is returned.
334template<typename T> inline bool StringToNumber(const char *s, T *val) {
335 FLATBUFFERS_ASSERT(s && val);
336 int64_t i64;
337 // The errno check isn't needed, will return MAX/MIN on overflow.
338 if (StringToIntegerImpl(&i64, s, 0, false)) {
339 const int64_t max = (flatbuffers::numeric_limits<T>::max)();
340 const int64_t min = flatbuffers::numeric_limits<T>::lowest();
341 if (i64 > max) {
342 *val = static_cast<T>(max);
343 return false;
344 }
345 if (i64 < min) {
346 // For unsigned types return max to distinguish from
347 // "no conversion can be performed" when 0 is returned.
348 *val = static_cast<T>(flatbuffers::is_unsigned<T>::value ? max : min);
349 return false;
350 }
351 *val = static_cast<T>(i64);
352 return true;
353 }
354 *val = 0;
355 return false;
356}
357
358template<> inline bool StringToNumber<int64_t>(const char *str, int64_t *val) {
359 return StringToIntegerImpl(val, str);
360}
361
362template<>
363inline bool StringToNumber<uint64_t>(const char *str, uint64_t *val) {
364 if (!StringToIntegerImpl(val, str)) return false;
365 // The strtoull accepts negative numbers:
366 // If the minus sign was part of the input sequence, the numeric value
367 // calculated from the sequence of digits is negated as if by unary minus
368 // in the result type, which applies unsigned integer wraparound rules.
369 // Fix this behaviour (except -0).
370 if (*val) {
371 auto s = str;
372 while (*s && !is_digit(*s)) s++;
373 s = (s > str) ? (s - 1) : s; // step back to one symbol
374 if (*s == '-') {
375 // For unsigned types return the max to distinguish from
376 // "no conversion can be performed".
377 *val = (flatbuffers::numeric_limits<uint64_t>::max)();
378 return false;
379 }
380 }
381 return true;
382}
383
384template<> inline bool StringToNumber(const char *s, float *val) {
385 return StringToFloatImpl(val, s);
386}
387
388template<> inline bool StringToNumber(const char *s, double *val) {
389 return StringToFloatImpl(val, s);
390}
391
392inline int64_t StringToInt(const char *s, int base = 10) {
393 int64_t val;
394 return StringToIntegerImpl(&val, s, base) ? val : 0;
395}
396
397inline uint64_t StringToUInt(const char *s, int base = 10) {
398 uint64_t val;
399 return StringToIntegerImpl(&val, s, base) ? val : 0;
400}
401
402typedef bool (*LoadFileFunction)(const char *filename, bool binary,
403 std::string *dest);
404typedef bool (*FileExistsFunction)(const char *filename);
405
406LoadFileFunction SetLoadFileFunction(LoadFileFunction load_file_function);
407
408FileExistsFunction SetFileExistsFunction(
409 FileExistsFunction file_exists_function);
410
411// Check if file "name" exists.
412bool FileExists(const char *name);
413
414// Check if "name" exists and it is also a directory.
415bool DirExists(const char *name);
416
417// Load file "name" into "buf" returning true if successful
418// false otherwise. If "binary" is false data is read
419// using ifstream's text mode, otherwise data is read with
420// no transcoding.
421bool LoadFile(const char *name, bool binary, std::string *buf);
422
423// Save data "buf" of length "len" bytes into a file
424// "name" returning true if successful, false otherwise.
425// If "binary" is false data is written using ifstream's
426// text mode, otherwise data is written with no
427// transcoding.
428bool SaveFile(const char *name, const char *buf, size_t len, bool binary);
429
430// Save data "buf" into file "name" returning true if
431// successful, false otherwise. If "binary" is false
432// data is written using ifstream's text mode, otherwise
433// data is written with no transcoding.
434inline bool SaveFile(const char *name, const std::string &buf, bool binary) {
435 return SaveFile(name, buf.c_str(), buf.size(), binary);
436}
437
438// Functionality for minimalistic portable path handling.
439
440// The functions below behave correctly regardless of whether posix ('/') or
441// Windows ('/' or '\\') separators are used.
442
443// Any new separators inserted are always posix.
444FLATBUFFERS_CONSTEXPR char kPathSeparator = '/';
445
446// Returns the path with the extension, if any, removed.
447std::string StripExtension(const std::string &filepath);
448
449// Returns the extension, if any.
450std::string GetExtension(const std::string &filepath);
451
452// Return the last component of the path, after the last separator.
453std::string StripPath(const std::string &filepath);
454
455// Strip the last component of the path + separator.
456std::string StripFileName(const std::string &filepath);
457
Austin Schuh272c6132020-11-14 16:37:52 -0800458// Concatenates a path with a filename, regardless of whether the path
Austin Schuhe89fa2d2019-08-14 20:24:23 -0700459// ends in a separator or not.
460std::string ConCatPathFileName(const std::string &path,
461 const std::string &filename);
462
463// Replaces any '\\' separators with '/'
464std::string PosixPath(const char *path);
465
466// This function ensure a directory exists, by recursively
467// creating dirs for any parts of the path that don't exist yet.
468void EnsureDirExists(const std::string &filepath);
469
470// Obtains the absolute path from any other path.
471// Returns the input path if the absolute path couldn't be resolved.
472std::string AbsolutePath(const std::string &filepath);
473
474// To and from UTF-8 unicode conversion functions
475
476// Convert a unicode code point into a UTF-8 representation by appending it
477// to a string. Returns the number of bytes generated.
478inline int ToUTF8(uint32_t ucc, std::string *out) {
479 FLATBUFFERS_ASSERT(!(ucc & 0x80000000)); // Top bit can't be set.
480 // 6 possible encodings: http://en.wikipedia.org/wiki/UTF-8
481 for (int i = 0; i < 6; i++) {
482 // Max bits this encoding can represent.
483 uint32_t max_bits = 6 + i * 5 + static_cast<int>(!i);
484 if (ucc < (1u << max_bits)) { // does it fit?
485 // Remaining bits not encoded in the first byte, store 6 bits each
486 uint32_t remain_bits = i * 6;
487 // Store first byte:
488 (*out) += static_cast<char>((0xFE << (max_bits - remain_bits)) |
489 (ucc >> remain_bits));
490 // Store remaining bytes:
491 for (int j = i - 1; j >= 0; j--) {
492 (*out) += static_cast<char>(((ucc >> (j * 6)) & 0x3F) | 0x80);
493 }
494 return i + 1; // Return the number of bytes added.
495 }
496 }
497 FLATBUFFERS_ASSERT(0); // Impossible to arrive here.
498 return -1;
499}
500
501// Converts whatever prefix of the incoming string corresponds to a valid
502// UTF-8 sequence into a unicode code. The incoming pointer will have been
503// advanced past all bytes parsed.
504// returns -1 upon corrupt UTF-8 encoding (ignore the incoming pointer in
505// this case).
506inline int FromUTF8(const char **in) {
507 int len = 0;
508 // Count leading 1 bits.
509 for (int mask = 0x80; mask >= 0x04; mask >>= 1) {
510 if (**in & mask) {
511 len++;
512 } else {
513 break;
514 }
515 }
516 if ((static_cast<unsigned char>(**in) << len) & 0x80)
517 return -1; // Bit after leading 1's must be 0.
518 if (!len) return *(*in)++;
519 // UTF-8 encoded values with a length are between 2 and 4 bytes.
520 if (len < 2 || len > 4) { return -1; }
521 // Grab initial bits of the code.
522 int ucc = *(*in)++ & ((1 << (7 - len)) - 1);
523 for (int i = 0; i < len - 1; i++) {
524 if ((**in & 0xC0) != 0x80) return -1; // Upper bits must 1 0.
525 ucc <<= 6;
526 ucc |= *(*in)++ & 0x3F; // Grab 6 more bits of the code.
527 }
528 // UTF-8 cannot encode values between 0xD800 and 0xDFFF (reserved for
529 // UTF-16 surrogate pairs).
530 if (ucc >= 0xD800 && ucc <= 0xDFFF) { return -1; }
531 // UTF-8 must represent code points in their shortest possible encoding.
532 switch (len) {
533 case 2:
534 // Two bytes of UTF-8 can represent code points from U+0080 to U+07FF.
535 if (ucc < 0x0080 || ucc > 0x07FF) { return -1; }
536 break;
537 case 3:
538 // Three bytes of UTF-8 can represent code points from U+0800 to U+FFFF.
539 if (ucc < 0x0800 || ucc > 0xFFFF) { return -1; }
540 break;
541 case 4:
542 // Four bytes of UTF-8 can represent code points from U+10000 to U+10FFFF.
543 if (ucc < 0x10000 || ucc > 0x10FFFF) { return -1; }
544 break;
545 }
546 return ucc;
547}
548
549#ifndef FLATBUFFERS_PREFER_PRINTF
550// Wraps a string to a maximum length, inserting new lines where necessary. Any
551// existing whitespace will be collapsed down to a single space. A prefix or
552// suffix can be provided, which will be inserted before or after a wrapped
553// line, respectively.
554inline std::string WordWrap(const std::string in, size_t max_length,
555 const std::string wrapped_line_prefix,
556 const std::string wrapped_line_suffix) {
557 std::istringstream in_stream(in);
558 std::string wrapped, line, word;
559
560 in_stream >> word;
561 line = word;
562
563 while (in_stream >> word) {
564 if ((line.length() + 1 + word.length() + wrapped_line_suffix.length()) <
565 max_length) {
566 line += " " + word;
567 } else {
568 wrapped += line + wrapped_line_suffix + "\n";
569 line = wrapped_line_prefix + word;
570 }
571 }
572 wrapped += line;
573
574 return wrapped;
575}
576#endif // !FLATBUFFERS_PREFER_PRINTF
577
578inline bool EscapeString(const char *s, size_t length, std::string *_text,
579 bool allow_non_utf8, bool natural_utf8) {
580 std::string &text = *_text;
581 text += "\"";
582 for (uoffset_t i = 0; i < length; i++) {
583 char c = s[i];
584 switch (c) {
585 case '\n': text += "\\n"; break;
586 case '\t': text += "\\t"; break;
587 case '\r': text += "\\r"; break;
588 case '\b': text += "\\b"; break;
589 case '\f': text += "\\f"; break;
590 case '\"': text += "\\\""; break;
591 case '\\': text += "\\\\"; break;
592 default:
593 if (c >= ' ' && c <= '~') {
594 text += c;
595 } else {
596 // Not printable ASCII data. Let's see if it's valid UTF-8 first:
597 const char *utf8 = s + i;
598 int ucc = FromUTF8(&utf8);
599 if (ucc < 0) {
600 if (allow_non_utf8) {
601 text += "\\x";
602 text += IntToStringHex(static_cast<uint8_t>(c), 2);
603 } else {
604 // There are two cases here:
605 //
606 // 1) We reached here by parsing an IDL file. In that case,
607 // we previously checked for non-UTF-8, so we shouldn't reach
608 // here.
609 //
610 // 2) We reached here by someone calling GenerateText()
611 // on a previously-serialized flatbuffer. The data might have
612 // non-UTF-8 Strings, or might be corrupt.
613 //
614 // In both cases, we have to give up and inform the caller
615 // they have no JSON.
616 return false;
617 }
618 } else {
619 if (natural_utf8) {
620 // utf8 points to past all utf-8 bytes parsed
621 text.append(s + i, static_cast<size_t>(utf8 - s - i));
622 } else if (ucc <= 0xFFFF) {
623 // Parses as Unicode within JSON's \uXXXX range, so use that.
624 text += "\\u";
625 text += IntToStringHex(ucc, 4);
626 } else if (ucc <= 0x10FFFF) {
627 // Encode Unicode SMP values to a surrogate pair using two \u
628 // escapes.
629 uint32_t base = ucc - 0x10000;
630 auto high_surrogate = (base >> 10) + 0xD800;
631 auto low_surrogate = (base & 0x03FF) + 0xDC00;
632 text += "\\u";
633 text += IntToStringHex(high_surrogate, 4);
634 text += "\\u";
635 text += IntToStringHex(low_surrogate, 4);
636 }
637 // Skip past characters recognized.
638 i = static_cast<uoffset_t>(utf8 - s - 1);
639 }
640 }
641 break;
642 }
643 }
644 text += "\"";
645 return true;
646}
647
Austin Schuh272c6132020-11-14 16:37:52 -0800648inline std::string BufferToHexText(const void *buffer, size_t buffer_size,
649 size_t max_length,
650 const std::string &wrapped_line_prefix,
651 const std::string &wrapped_line_suffix) {
652 std::string text = wrapped_line_prefix;
653 size_t start_offset = 0;
654 const char *s = reinterpret_cast<const char *>(buffer);
655 for (size_t i = 0; s && i < buffer_size; i++) {
656 // Last iteration or do we have more?
657 bool have_more = i + 1 < buffer_size;
658 text += "0x";
659 text += IntToStringHex(static_cast<uint8_t>(s[i]), 2);
660 if (have_more) { text += ','; }
661 // If we have more to process and we reached max_length
662 if (have_more &&
663 text.size() + wrapped_line_suffix.size() >= start_offset + max_length) {
664 text += wrapped_line_suffix;
665 text += '\n';
666 start_offset = text.size();
667 text += wrapped_line_prefix;
668 }
669 }
670 text += wrapped_line_suffix;
671 return text;
672}
673
Austin Schuhe89fa2d2019-08-14 20:24:23 -0700674// Remove paired quotes in a string: "text"|'text' -> text.
675std::string RemoveStringQuotes(const std::string &s);
676
677// Change th global C-locale to locale with name <locale_name>.
678// Returns an actual locale name in <_value>, useful if locale_name is "" or
679// null.
680bool SetGlobalTestLocale(const char *locale_name,
681 std::string *_value = nullptr);
682
683// Read (or test) a value of environment variable.
684bool ReadEnvironmentVariable(const char *var_name,
685 std::string *_value = nullptr);
686
687// MSVC specific: Send all assert reports to STDOUT to prevent CI hangs.
688void SetupDefaultCRTReportMode();
689
690} // namespace flatbuffers
691
692#endif // FLATBUFFERS_UTIL_H_