Frontend: Define __SANITIZE_*__ macros for certain sanitizers.

Per discussion with @ojhunt and @AaronBallman we are moving towards
predefined macros and away from __has_feature and __has_extension
for detecting sanitizers and other similar features. The rationale
is that __has_feature is only really meant for standardized features
(see the comment at the top of clang/include/clang/Basic/Features.def),
and __has_extension has the issues discovered as part of #153104.

Let's start by defining macros for ASan, HWASan and TSan, consistently
with gcc.

Reviewers: vitalybuka, ojhunt, AaronBallman, fmayer

Reviewed By: fmayer, vitalybuka

Pull Request: https://github.com/llvm/llvm-project/pull/153888

1 files changed, 7 insertions, 0 deletions

diff --git a/clang/lib/Frontend/InitPreprocessor.cpp b/clang/lib/Frontend/InitPreprocessor.cpp
index 008a35d..5980806 100644
--- a/clang/lib/Frontend/InitPreprocessor.cpp
+++ b/clang/lib/Frontend/InitPreprocessor.cpp
@@ -1519,6 +1519,13 @@ static void InitializePredefinedMacros(const TargetInfo &TI,
   if (TI.getTriple().isOSBinFormatELF())
     Builder.defineMacro("__ELF__");
 
+  if (LangOpts.Sanitize.has(SanitizerKind::Address))
+    Builder.defineMacro("__SANITIZE_ADDRESS__");
+  if (LangOpts.Sanitize.has(SanitizerKind::HWAddress))
+    Builder.defineMacro("__SANITIZE_HWADDRESS__");
+  if (LangOpts.Sanitize.has(SanitizerKind::Thread))
+    Builder.defineMacro("__SANITIZE_THREAD__");
+
   // Target OS macro definitions.
   if (PPOpts.DefineTargetOSMacros) {
     const llvm::Triple &Triple = TI.getTriple();