[PATCH] D144654: [Lex] Warn when defining or undefining any builtin macro

[John Brawn via Phabricator via cfe-commits]

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Currently we warn when MI->isBuiltinMacro, but this is only true for builtin macros that require processing when expanding. Checking SourceMgr.isWrittenInBuiltinFile in addition to this will mean that we catch all builtin macros.

As part of doing this I've also moved the handling of undefining from CheckMacroName to HandleUndefDirective, as it doesn't really make sense to handle undefining in CheckMacroName but defining in HandleDefineDirective. It would be nice to instead handle both in CheckMacroName, but that isn't possible as the handling of defines requires looking at what the name is being defined to.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D144654

Files:
  clang/lib/Lex/PPDirectives.cpp
  clang/test/Preprocessor/macro-reserved.c
  clang/test/Preprocessor/macro-reserved.cpp

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