https://github.com/cor3ntin created https://github.com/llvm/llvm-project/pull/212131
As a DR in all language modes. Because we already supported the feature this is only modifying the extensions warnings. >From 7ee4747282606218f344bbdf38dec5f1d935a946 Mon Sep 17 00:00:00 2001 From: Corentin Jabot <[email protected]> Date: Sun, 26 Jul 2026 18:43:08 +0200 Subject: [PATCH] [Clang] Implement P3658R1 As a DR in all language modes. Because we already supported the feature this is only modifying the extensions warnings. --- clang/docs/ReleaseNotes.md | 4 +++ .../include/clang/Basic/DiagnosticLexKinds.td | 2 ++ clang/lib/Lex/Lexer.cpp | 35 +++++++++++-------- clang/lib/Lex/UnicodeCharSets.h | 6 ++-- clang/test/Lexer/unicode.c | 20 +++++++---- clang/www/cxx_status.html | 2 +- 6 files changed, 42 insertions(+), 27 deletions(-) diff --git a/clang/docs/ReleaseNotes.md b/clang/docs/ReleaseNotes.md index 83a2b10d96046..7958f11e9cae0 100644 --- a/clang/docs/ReleaseNotes.md +++ b/clang/docs/ReleaseNotes.md @@ -91,6 +91,10 @@ features cannot lower the translation-unit ABI level; #### C++2d Feature Support +- Clang now supports [P3658R1](https://wg21.link/p3658r1) (Adjust identifier + following new Unicode recommendations), applied as a DR to all C++ language + modes. + #### C++2c Feature Support - Clang now supports [P3533R2](https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2025/p3533r2.html) (constexpr virtual inheritance). diff --git a/clang/include/clang/Basic/DiagnosticLexKinds.td b/clang/include/clang/Basic/DiagnosticLexKinds.td index 18143fc9f0feb..8330166e05199 100644 --- a/clang/include/clang/Basic/DiagnosticLexKinds.td +++ b/clang/include/clang/Basic/DiagnosticLexKinds.td @@ -145,6 +145,8 @@ def warn_utf8_symbol_homoglyph : Warning< def warn_utf8_symbol_zero_width : Warning< "identifier contains character %0 that is invisible in " "some environments">, InGroup<DiagGroup<"unicode-zero-width">>; +defm mathematical_notation : CXX29Compat< + "mathematical notation character %0 in an identifier is">; def ext_mathematical_notation : ExtWarn< "mathematical notation character %0 in an identifier is a Clang extension">, InGroup<DiagGroup<"mathematical-notation-identifier-extension">>; diff --git a/clang/lib/Lex/Lexer.cpp b/clang/lib/Lex/Lexer.cpp index 5826485c8b16a..d63865b024b82 100644 --- a/clang/lib/Lex/Lexer.cpp +++ b/clang/lib/Lex/Lexer.cpp @@ -1603,12 +1603,9 @@ static bool isUnicodeWhitespace(uint32_t Codepoint) { return UnicodeWhitespaceChars.contains(Codepoint); } -// To mitigate https://github.com/llvm/llvm-project/issues/54732, -// we allow "Mathematical Notation Characters" in identifiers. -// This is a proposed profile that extends the XID_Start/XID_continue -// with mathematical symbols, superscipts and subscripts digits -// found in some production software. -// https://www.unicode.org/L2/L2022/22230-math-profile.pdf +// The mathematical compatibility notation profile extends XID_Start and +// XID_Continue with mathematical symbols, superscript and subscript digits. +// https://www.unicode.org/reports/tr31/#Mathematical_Compatibility_Notation static bool isMathematicalExtensionID(uint32_t C, const LangOptions &LangOpts, bool IsStart, bool &IsExtension) { static const llvm::sys::UnicodeCharSet MathStartChars( @@ -1677,8 +1674,10 @@ static bool isAllowedInitiallyIDChar(uint32_t C, const LangOptions &LangOpts, return !C99DisallowedInitialIDChars.contains(C); } -static void diagnoseExtensionInIdentifier(DiagnosticsEngine &Diags, uint32_t C, - CharSourceRange Range) { +static void +diagnoseMathematicalNotationInIdentifier(DiagnosticsEngine &Diags, + const LangOptions &LangOpts, + uint32_t C, CharSourceRange Range) { static const llvm::sys::UnicodeCharSet MathStartChars( MathematicalNotationProfileIDStartRanges); @@ -1689,7 +1688,11 @@ static void diagnoseExtensionInIdentifier(DiagnosticsEngine &Diags, uint32_t C, (void)MathContinueChars; assert((MathStartChars.contains(C) || MathContinueChars.contains(C)) && "Unexpected mathematical notation codepoint"); - Diags.Report(Range.getBegin(), diag::ext_mathematical_notation) + unsigned DiagID = LangOpts.CPlusPlus + ? DiagnosticIDs::getCompatDiagId( + LangOpts, diag_compat::mathematical_notation) + : diag::ext_mathematical_notation; + Diags.Report(Range.getBegin(), DiagID) << EscapeSingleCodepointForDiagnostic(C) << Range; } @@ -1861,8 +1864,9 @@ bool Lexer::tryConsumeIdentifierUCN(const char *&CurPtr, unsigned Size, // Carry on as if the codepoint was valid for recovery purposes. } else if (!isLexingRawMode()) { if (IsExtension) - diagnoseExtensionInIdentifier(PP->getDiagnostics(), CodePoint, - makeCharRange(*this, CurPtr, UCNPtr)); + diagnoseMathematicalNotationInIdentifier( + PP->getDiagnostics(), LangOpts, CodePoint, + makeCharRange(*this, CurPtr, UCNPtr)); maybeDiagnoseIDCharCompat(PP->getDiagnostics(), CodePoint, makeCharRange(*this, CurPtr, UCNPtr), @@ -1917,8 +1921,8 @@ bool Lexer::tryConsumeIdentifierUTF8Char(const char *&CurPtr, Token &Result) { // valid for recovery purposes. } else if (!isLexingRawMode()) { if (IsExtension) - diagnoseExtensionInIdentifier( - PP->getDiagnostics(), CodePoint, + diagnoseMathematicalNotationInIdentifier( + PP->getDiagnostics(), LangOpts, CodePoint, makeCharRange(*this, CharStart, UnicodePtr)); maybeDiagnoseIDCharCompat(PP->getDiagnostics(), CodePoint, makeCharRange(*this, CharStart, UnicodePtr), @@ -1942,8 +1946,9 @@ bool Lexer::LexUnicodeIdentifierStart(Token &Result, uint32_t C, if (!isLexingRawMode() && !ParsingPreprocessorDirective && !PP->isPreprocessedOutput()) { if (IsExtension) - diagnoseExtensionInIdentifier(PP->getDiagnostics(), C, - makeCharRange(*this, BufferPtr, CurPtr)); + diagnoseMathematicalNotationInIdentifier( + PP->getDiagnostics(), LangOpts, C, + makeCharRange(*this, BufferPtr, CurPtr)); maybeDiagnoseIDCharCompat(PP->getDiagnostics(), C, makeCharRange(*this, BufferPtr, CurPtr), /*IsFirst=*/true); diff --git a/clang/lib/Lex/UnicodeCharSets.h b/clang/lib/Lex/UnicodeCharSets.h index 0ceab85d15586..eaee53172050f 100644 --- a/clang/lib/Lex/UnicodeCharSets.h +++ b/clang/lib/Lex/UnicodeCharSets.h @@ -393,9 +393,7 @@ static const llvm::sys::UnicodeCharRange XIDContinueRanges[] = { {0x1FBF0, 0x1FBF9}, {0xE0100, 0xE01EF}, }; -// Clang supports the "Mathematical notation profile" as an extension, -// as described in https://www.unicode.org/L2/L2022/22230-math-profile.pdf -// Math_Start +// Unicode 18.0 ID_Compat_Math_Start static const llvm::sys::UnicodeCharRange MathematicalNotationProfileIDStartRanges[] = { {0x02202, 0x02202}, // โ @@ -413,7 +411,7 @@ static const llvm::sys::UnicodeCharRange {0x1D7C3, 0x1D7C3}, // ๐ }; -// Math_Continue +// Unicode 18.0 ID_Compat_Math_Continue, excluding ID_Compat_Math_Start static const llvm::sys::UnicodeCharRange MathematicalNotationProfileIDContinueRanges[] = { {0x000B2, 0x000B3}, // ยฒ-ยณ diff --git a/clang/test/Lexer/unicode.c b/clang/test/Lexer/unicode.c index 0974c976aee1c..53acca6ba04b7 100644 --- a/clang/test/Lexer/unicode.c +++ b/clang/test/Lexer/unicode.c @@ -1,6 +1,8 @@ // RUN: %clang_cc1 -fsyntax-only -verify -x c -std=c11 %s -// RUN: %clang_cc1 -fsyntax-only -verify=expected,c2x -x c -std=c2x %s -// RUN: %clang_cc1 -fsyntax-only -verify=expected,cxx -x c++ -std=c++11 %s +// RUN: %clang_cc1 -fsyntax-only -verify=expected,c2x,math -x c -std=c2x %s +// RUN: %clang_cc1 -fsyntax-only -verify=expected,cxx,math,ext -x c++ -std=c++11 %s +// RUN: %clang_cc1 -fsyntax-only -verify=expected,cxx -x c++ -std=c++2d %s +// RUN: %clang_cc1 -fsyntax-only -verify=expected,cxx,math,compat -x c++ -std=c++2d -Wpre-c++2d-compat %s // RUN: %clang_cc1 -std=c99 -E -DPP_ONLY=1 %s | FileCheck %s --strict-whitespace // RUN: %clang_cc1 -E -DPP_ONLY=1 %s | FileCheck %s --strict-whitespace // UNSUPPORTED: system-zos @@ -52,19 +54,23 @@ extern int a\N{TANGSALETTERGA}; // expected-error {{'TANGSALETTERGA' is not a va // expected-error {{expected ';' after top level declarator}} \ // expected-note {{character names in Unicode escape sequences are sensitive to case and whitespace}} -extern int ๐; // expected-warning {{mathematical notation character '๐' U+1D6DB in an identifier is a Clang extension}} +// Mathematical notation characters are standard in C++ (P3658R1) and a Clang +// extension in C. The 'math' prefix matches whichever warning applies. +extern int ๐; // c2x-warning {{mathematical notation character '๐' U+1D6DB in an identifier is a Clang extension}} \ + ext-warning {{mathematical notation character '๐' U+1D6DB in an identifier is a C++2d extension}} \ + compat-warning {{mathematical notation character '๐' U+1D6DB in an identifier is incompatible with C++ standards before C++2d}} extern int โ; // expected-error {{character 'โ' U+2089 not allowed at the start of an identifier}} \\ expected-warning {{declaration does not declare anything}} extern int a\N{PICKLE}; // expected-error {{character '๐ซ' U+1FADD not allowed in an identifier}} -int aยนbโโโโโ; // expected-warning 6{{mathematical notation character}} +int aยนbโโโโโ; // math-warning 6{{mathematical notation character}} -int \u{221E} = 1; // expected-warning {{mathematical notation character}} +int \u{221E} = 1; // math-warning {{mathematical notation character}} int \N{MATHEMATICAL SANS-SERIF BOLD ITALIC PARTIAL DIFFERENTIAL} = 1; - // expected-warning@-1 {{mathematical notation character}} + // math-warning@-1 {{mathematical notation character}} -int a\N{SUBSCRIPT EQUALS SIGN} = 1; // expected-warning {{mathematical notation character}} +int a\N{SUBSCRIPT EQUALS SIGN} = 1; // math-warning {{mathematical notation character}} // This character doesn't have the XID_Start property extern int \U00016AC0; // TANGSA DIGIT ZERO // cxx-error {{expected unqualified-id}} \ diff --git a/clang/www/cxx_status.html b/clang/www/cxx_status.html index a12115f8b785a..16ebeb1052b79 100755 --- a/clang/www/cxx_status.html +++ b/clang/www/cxx_status.html @@ -137,7 +137,7 @@ <h2 id="cxx29">C++2d implementation status</h2> <tr> <td>Adjust identifier following new Unicode recommendations</td> <td><a href="https://wg21.link/P3658R1";>P3658R1</a> <a href="#dr">(DR)</a></td> - <td class="none" align="center">No</td> + <td class="full" align="center">Clang 24</td> </tr> <tr> <td><code>return_value</code> & <code>return_void</code> are not mutually exclusive</td> _______________________________________________ cfe-commits mailing list [email protected] https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
