[all-commits] [llvm/llvm-project] 13629b: [C2x] Support -std=c23 and -std=gnu23

[Aaron Ballman via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 13629b140801870feff855ca168edf6b34dbef8d
      https://github.com/llvm/llvm-project/commit/13629b140801870feff855ca168edf6b34dbef8d
  Author: Aaron Ballman <aaron at aaronballman.com>
  Date:   2023-08-10 (Thu, 10 Aug 2023)

  Changed paths:
    M clang-tools-extra/clangd/index/StdLib.cpp
    M clang/docs/ReleaseNotes.rst
    M clang/include/clang/Basic/LangStandards.def
    M clang/lib/Frontend/InitPreprocessor.cpp
    M clang/lib/Headers/limits.h
    M clang/lib/Headers/stdalign.h
    M clang/lib/Headers/stdarg.h
    M clang/lib/Headers/stdatomic.h
    M clang/lib/Headers/stddef.h
    M clang/lib/Headers/stdint.h
    M clang/test/C/C11/n1330.c
    M clang/test/C/drs/dr0xx.c
    M clang/test/C/drs/dr2xx.c
    M clang/test/C/drs/dr3xx.c
    M clang/test/C/drs/dr411.c
    M clang/test/Driver/unknown-std.c
    M clang/test/Headers/limits.cpp
    M clang/test/Headers/stdint.c
    M clang/test/Lexer/unicode.c
    M clang/test/Lexer/utf8-char-literal.cpp
    M clang/test/Preprocessor/c2x.c
    M clang/test/Preprocessor/ucn-allowed-chars.c
    M clang/test/Sema/atomic-expr.c

  Log Message:
  -----------
  [C2x] Support -std=c23 and -std=gnu23

C2x was finalized at the June 2023 WG14 meeting. The DIS is out for
balloting and the comment period for that closes later this year/early
next year. While that does leave an opportunity for more changes to the
standard during the DIS ballot resolution process, only editorial
changes are anticipated and as a result, the C committee considers C2x
to be final. The committee took a straw poll on what we'd prefer the
informal name of the standard be, and we decided it should be called
C23 regardless of what year ISO publishes it.

However, because the final publication is not out, this patch does not
add the language standard alias for the -std=iso9899:<year> spelling of
the standard mode; that will be added once ISO finally publishes the
document and the year chosen will match the publication date.

This also changes the value of __STDC_VERSION__ from the placeholder
value 202000L to the final value 202311L.

Subsequent patches will start renaming things from c2x to c23, cleaning
up documentation, etc.

Differential Revision: https://reviews.llvm.org/D157606