[clang] e29eb66 - [Clang] Slightly tweak the code to try to fix a potential codegen issue in #142592

[Corentin Jabot via cfe-commits]

Author: Corentin Jabot
Date: 2025-06-03T16:18:17+02:00
New Revision: e29eb6637d6b8ee54f746a9c914304f83309c4ee

URL: https://github.com/llvm/llvm-project/commit/e29eb6637d6b8ee54f746a9c914304f83309c4ee
DIFF: https://github.com/llvm/llvm-project/commit/e29eb6637d6b8ee54f746a9c914304f83309c4ee.diff

LOG: [Clang] Slightly tweak the code to try to fix a potential codegen issue in #142592

Added: 
    

Modified: 
    clang/include/clang/Lex/Preprocessor.h
    clang/lib/Lex/PPExpressions.cpp
    clang/test/SemaCXX/libstdcxx_pair_swap_hack.cpp

Removed: 
    


################################################################################
diff  --git a/clang/include/clang/Lex/Preprocessor.h b/clang/include/clang/Lex/Preprocessor.h
index cab398ad4a865..78be2bd64d61c 100644
--- a/clang/include/clang/Lex/Preprocessor.h
+++ b/clang/include/clang/Lex/Preprocessor.h
@@ -132,7 +132,7 @@ enum class EmbedResult {
 struct CXXStandardLibraryVersionInfo {
   enum Library { Unknown, LibStdCXX };
   Library Lib;
-  unsigned Version;
+  std::uint64_t Version;
 };
 
 /// Engages in a tight little dance with the lexer to efficiently
@@ -2717,8 +2717,8 @@ class Preprocessor {
   std::optional<CXXStandardLibraryVersionInfo> CXXStandardLibraryVersion;
 
 public:
-  std::optional<unsigned> getStdLibCxxVersion();
-  bool NeedsStdLibCxxWorkaroundBefore(unsigned FixedVersion);
+  std::optional<std::uint64_t> getStdLibCxxVersion();
+  bool NeedsStdLibCxxWorkaroundBefore(std::uint64_t FixedVersion);
 
 private:
   //===--------------------------------------------------------------------===//

diff  --git a/clang/lib/Lex/PPExpressions.cpp b/clang/lib/Lex/PPExpressions.cpp
index 7b1dbb29b3b24..d18e56e7d478a 100644
--- a/clang/lib/Lex/PPExpressions.cpp
+++ b/clang/lib/Lex/PPExpressions.cpp
@@ -984,14 +984,9 @@ static std::optional<CXXStandardLibraryVersionInfo>
 getCXXStandardLibraryVersion(Preprocessor &PP, StringRef MacroName,
                              CXXStandardLibraryVersionInfo::Library Lib) {
   MacroInfo *Macro = PP.getMacroInfo(PP.getIdentifierInfo(MacroName));
-  if (!Macro)
+  if (!Macro || Macro->getNumTokens() != 1 || !Macro->isObjectLike())
     return std::nullopt;
 
-  if (Macro->getNumTokens() != 1 || !Macro->isObjectLike()) {
-    Macro->dump();
-    return std::nullopt;
-  }
-
   const Token &RevisionDateTok = Macro->getReplacementToken(0);
 
   bool Invalid = false;
@@ -999,19 +994,16 @@ getCXXStandardLibraryVersion(Preprocessor &PP, StringRef MacroName,
   llvm::StringRef RevisionDate =
       PP.getSpelling(RevisionDateTok, Buffer, &Invalid);
   if (!Invalid) {
-    llvm::errs() << RevisionDate << "\n";
-    unsigned Value;
+    std::uint64_t Value;
     // We don't use NumericParser to avoid diagnostics
-    if (!RevisionDate.consumeInteger(10, Value)) {
-      llvm::errs() << "Value:" << Value << "\n";
+    if (!RevisionDate.consumeInteger(10, Value))
       return CXXStandardLibraryVersionInfo{Lib, Value};
-    }
   }
   return CXXStandardLibraryVersionInfo{CXXStandardLibraryVersionInfo::Unknown,
                                        0};
 }
 
-std::optional<unsigned> Preprocessor::getStdLibCxxVersion() {
+std::optional<uint64_t> Preprocessor::getStdLibCxxVersion() {
   if (!CXXStandardLibraryVersion)
     CXXStandardLibraryVersion = getCXXStandardLibraryVersion(
         *this, "__GLIBCXX__", CXXStandardLibraryVersionInfo::LibStdCXX);
@@ -1024,10 +1016,10 @@ std::optional<unsigned> Preprocessor::getStdLibCxxVersion() {
   return std::nullopt;
 }
 
-bool Preprocessor::NeedsStdLibCxxWorkaroundBefore(unsigned FixedVersion) {
+bool Preprocessor::NeedsStdLibCxxWorkaroundBefore(uint64_t FixedVersion) {
   assert(FixedVersion >= 2000'00'00 && FixedVersion <= 2100'00'00 &&
          "invalid value for __GLIBCXX__");
-  std::optional<unsigned> Ver = getStdLibCxxVersion();
+  std::optional<std::uint64_t> Ver = getStdLibCxxVersion();
   if (!Ver)
     return false;
   return *Ver < FixedVersion;

diff  --git a/clang/test/SemaCXX/libstdcxx_pair_swap_hack.cpp b/clang/test/SemaCXX/libstdcxx_pair_swap_hack.cpp
index 6b0adea930abf..6b8ca4f740914 100644
--- a/clang/test/SemaCXX/libstdcxx_pair_swap_hack.cpp
+++ b/clang/test/SemaCXX/libstdcxx_pair_swap_hack.cpp
@@ -7,15 +7,15 @@
 // The same problem afflicts a bunch of other class templates. Those
 // affected are array, pair, priority_queue, stack, and queue.
 
-// RUN: %clang_cc1 -fsyntax-only %s -std=c++11 -verify -fexceptions -fcxx-exceptions -Wextra -D__GLIBCXX__=20100000L -DCLASS=array
-// RUN: %clang_cc1 -fsyntax-only %s -std=c++11 -verify -fexceptions -fcxx-exceptions -Wextra -D__GLIBCXX__=20100000L -DCLASS=array -DPR28423
-// RUN: %clang_cc1 -fsyntax-only %s -std=c++11 -verify -fexceptions -fcxx-exceptions -Wextra -D__GLIBCXX__=20100000L -DCLASS=pair
-// RUN: %clang_cc1 -fsyntax-only %s -std=c++11 -verify -fexceptions -fcxx-exceptions -Wextra -D__GLIBCXX__=20100000L -DCLASS=priority_queue
-// RUN: %clang_cc1 -fsyntax-only %s -std=c++11 -verify -fexceptions -fcxx-exceptions -Wextra -D__GLIBCXX__=20100000L -DCLASS=stack
-// RUN: %clang_cc1 -fsyntax-only %s -std=c++11 -verify -fexceptions -fcxx-exceptions -Wextra -D__GLIBCXX__=20100000L -DCLASS=queue
+// RUN: %clang_cc1 -fsyntax-only %s -std=c++11 -verify -fexceptions -fcxx-exceptions -D__GLIBCXX__=20100000L -DCLASS=array
+// RUN: %clang_cc1 -fsyntax-only %s -std=c++11 -verify -fexceptions -fcxx-exceptions -D__GLIBCXX__=20100000L -DCLASS=array -DPR28423
+// RUN: %clang_cc1 -fsyntax-only %s -std=c++11 -verify -fexceptions -fcxx-exceptions -D__GLIBCXX__=20100000L -DCLASS=pair
+// RUN: %clang_cc1 -fsyntax-only %s -std=c++11 -verify -fexceptions -fcxx-exceptions -D__GLIBCXX__=20100000L -DCLASS=priority_queue
+// RUN: %clang_cc1 -fsyntax-only %s -std=c++11 -verify -fexceptions -fcxx-exceptions -D__GLIBCXX__=20100000L -DCLASS=stack
+// RUN: %clang_cc1 -fsyntax-only %s -std=c++11 -verify -fexceptions -fcxx-exceptions -D__GLIBCXX__=20100000L -DCLASS=queue
 //
-// RUN: %clang_cc1 -fsyntax-only %s -std=c++11 -verify -fexceptions -fcxx-exceptions -Wextra -D__GLIBCXX__=20100000L -DCLASS=array -DNAMESPACE=__debug
-// RUN: %clang_cc1 -fsyntax-only %s -std=c++11 -verify -fexceptions -fcxx-exceptions -Wextra -D__GLIBCXX__=20100000L -DCLASS=array -DNAMESPACE=__profile
+// RUN: %clang_cc1 -fsyntax-only %s -std=c++11 -verify -fexceptions -fcxx-exceptions -D__GLIBCXX__=20100000L -DCLASS=array -DNAMESPACE=__debug
+// RUN: %clang_cc1 -fsyntax-only %s -std=c++11 -verify -fexceptions -fcxx-exceptions -D__GLIBCXX__=20100000L -DCLASS=array -DNAMESPACE=__profile
 
 // MSVC's standard library uses a very similar pattern that relies on delayed
 // parsing of exception specifications.