[all-commits] [llvm/llvm-project] 26c695: Support macro deprecation #pragma clang deprecated

[thegreatbeanz via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 26c695b7893071d5e69afbaa70c4850ab2e468be
      https://github.com/llvm/llvm-project/commit/26c695b7893071d5e69afbaa70c4850ab2e468be
  Author: Chris Bieneman <chris.bieneman at me.com>
  Date:   2021-07-29 (Thu, 29 Jul 2021)

  Changed paths:
    M clang/docs/LanguageExtensions.rst
    M clang/include/clang/Basic/DiagnosticGroups.td
    M clang/include/clang/Basic/DiagnosticLexKinds.td
    M clang/include/clang/Basic/IdentifierTable.h
    M clang/include/clang/Lex/Preprocessor.h
    M clang/lib/Lex/PPDirectives.cpp
    M clang/lib/Lex/PPExpressions.cpp
    M clang/lib/Lex/PPMacroExpansion.cpp
    M clang/lib/Lex/Pragma.cpp
    M clang/lib/Lex/Preprocessor.cpp
    A clang/test/Lexer/deprecate-macro.c

  Log Message:
  -----------
  Support macro deprecation #pragma clang deprecated

This patch adds `#pragma clang deprecated` to enable deprecation of
preprocessor macros.

The macro must be defined before `#pragma clang deprecated`. When
deprecating a macro a custom message may be optionally provided.

Warnings are emitted at the use site of a deprecated macro, and can be
controlled via the `-Wdeprecated` warning group.

This patch takes some rough inspiration and a few lines of code from
https://reviews.llvm.org/D67935.

Reviewed By: aaron.ballman

Differential Revision: https://reviews.llvm.org/D106732