upstream_utils/llvm_patches/0020-Prefer-fmtlib.patch

From 8834260a9ee172311cc08d0b4e4e958bf36a260f Mon Sep 17 00:00:00 2001
From: PJ Reiniger <pj.reiniger@gmail.com>
Date: Sun, 8 May 2022 16:46:20 -0400
Subject: [PATCH 20/28] Prefer fmtlib

---
 llvm/lib/Support/ErrorHandling.cpp | 20 ++++++--------------
 1 file changed, 6 insertions(+), 14 deletions(-)

diff --git a/llvm/lib/Support/ErrorHandling.cpp b/llvm/lib/Support/ErrorHandling.cpp
index ec1a1633a..8de7b726d 100644
--- a/llvm/lib/Support/ErrorHandling.cpp
+++ b/llvm/lib/Support/ErrorHandling.cpp
@@ -22,7 +22,7 @@
 #include "llvm/Support/Signals.h"
 #include "llvm/Support/Threading.h"
 #include "llvm/Support/WindowsError.h"
-#include "llvm/Support/raw_ostream.h"
+#include "fmt/format.h"
 #include <cassert>
 #include <cstdlib>
 #include <mutex>
@@ -93,15 +93,7 @@ void llvm::report_fatal_error(std::string_view Reason, bool GenCrashDiag) {
   if (handler) {
     handler(handlerData, std::string{Reason}.c_str(), GenCrashDiag);
   } else {
-    // Blast the result out to stderr.  We don't try hard to make sure this
-    // succeeds (e.g. handling EINTR) and we can't use errs() here because
-    // raw ostreams can call report_fatal_error.
-    SmallVector<char, 64> Buffer;
-    raw_svector_ostream OS(Buffer);
-    OS << "LLVM ERROR: " << Reason << "\n";
-    std::string_view MessageStr = OS.str();
-    ssize_t written = ::write(2, MessageStr.data(), MessageStr.size());
-    (void)written; // If something went wrong, we deliberately just give up.
+    fmt::print(stderr, "LLVM ERROR: {}\n", Reason);
   }
 
   // If we reached here, we are failing ungracefully. Run the interrupt handlers
@@ -173,11 +165,11 @@ void llvm::llvm_unreachable_internal(const char *msg, const char *file,
   // llvm_unreachable is intended to be used to indicate "impossible"
   // situations, and not legitimate runtime errors.
   if (msg)
-    dbgs() << msg << "\n";
-  dbgs() << "UNREACHABLE executed";
+    fmt::print(stderr, "{}\n", msg);
+  std::fputs("UNREACHABLE executed", stderr);
   if (file)
-    dbgs() << " at " << file << ":" << line;
-  dbgs() << "!\n";
+    fmt::print(stderr, " at {}:{}", file, line);
+  fmt::print(stderr, "!\n");
   abort();
 #ifdef LLVM_BUILTIN_UNREACHABLE
   // Windows systems and possibly others don't declare abort() to be noreturn,