[all-commits] [llvm/llvm-project] 304e97: [Clang] Correctly handle $, @, and ` when represen...

[cor3ntin via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 304e97469455b57f6496f68fef569eeaed3a2cd8
      https://github.com/llvm/llvm-project/commit/304e97469455b57f6496f68fef569eeaed3a2cd8
  Author: Corentin Jabot <corentinjabot at gmail.com>
  Date:   2023-07-12 (Wed, 12 Jul 2023)

  Changed paths:
    M clang/docs/ReleaseNotes.rst
    M clang/include/clang/Basic/DiagnosticLexKinds.td
    M clang/lib/Lex/Lexer.cpp
    M clang/lib/Lex/LiteralSupport.cpp
    M clang/test/Lexer/char-literal.cpp
    M clang/test/Lexer/utf8-char-literal.cpp
    M clang/test/Preprocessor/ucn-allowed-chars.c
    M clang/test/Preprocessor/ucn-pp-identifier.c

  Log Message:
  -----------
  [Clang] Correctly handle $, @, and ` when represented as UCN

This covers
 * P2558R2 (C++, wg21.link/P2558)
 * N2701 (C, https://www.open-std.org/jtc1/sc22/wg14/www/docs/n2701.htm)
 * N3124 (C, https://www.open-std.org/jtc1/sc22/wg14/www/docs/n3124.pdf)

This patch
 * Disallow representing $ as a UCN in all language mode, which did not
   properly work (see GH62133), and which in made ill-formed in
   C++ and C by P2558 and N3124 respectively
 * Allow a UCN for any character in C2X, in string and character
   literals

Fixes #62133

Reviewed By: #clang-language-wg, tahonermann

Differential Revision: https://reviews.llvm.org/D153621