https://github.com/hongtaihu updated https://github.com/llvm/llvm-project/pull/207130
>From 30cc618a32fdf8374d9b108f7788cf7e1731bdf1 Mon Sep 17 00:00:00 2001 From: hongtaihu <[email protected]> Date: Thu, 2 Jul 2026 14:43:32 +0800 Subject: [PATCH] [clang][Preprocessor] Fix expansion locations for feature-like builtin macros Fixes #196067. This patch fixes the expansion locations of synthesized tokens produced by feature-like builtin macros such as `__has_builtin(...)`. Feature-like builtin macros lex past the macro name while evaluating their arguments. `ExpandBuiltinMacro()` used the final `Tok` location as both the expansion start and end when creating the synthesized result token, so `__has_builtin(...)` results were anchored at the closing paren rather than the builtin macro invocation. Fix by saving the macro-name location before argument parsing and using it as the expansion start. The expansion end remains the final `Tok` location. Add a `syntax::TokenCollector` regression test for a valid `__has_builtin(...)` expansion and the `__is_identifier;` recovery path. Assisted-by: OpenAI Codex --- clang/lib/Lex/PPMacroExpansion.cpp | 3 ++- clang/unittests/Tooling/Syntax/TokensTest.cpp | 19 +++++++++++++++++++ 2 files changed, 21 insertions(+), 1 deletion(-) diff --git a/clang/lib/Lex/PPMacroExpansion.cpp b/clang/lib/Lex/PPMacroExpansion.cpp index 23a21f42b8e3a..e09e80a063c4e 100644 --- a/clang/lib/Lex/PPMacroExpansion.cpp +++ b/clang/lib/Lex/PPMacroExpansion.cpp @@ -1619,6 +1619,7 @@ void Preprocessor::ExpandBuiltinMacro(Token &Tok) { // Figure out which token this is. IdentifierInfo *II = Tok.getIdentifierInfo(); assert(II && "Can't be a macro without id info!"); + SourceLocation MacroNameLoc = Tok.getLocation(); // If this is an _Pragma or Microsoft __pragma directive, expand it, // invoke the pragma handler, then lex the token after it. @@ -2096,7 +2097,7 @@ void Preprocessor::ExpandBuiltinMacro(Token &Tok) { } else { llvm_unreachable("Unknown identifier!"); } - CreateString(OS.str(), Tok, Tok.getLocation(), Tok.getLocation()); + CreateString(OS.str(), Tok, MacroNameLoc, Tok.getLocation()); Tok.setFlagValue(Token::StartOfLine, IsAtStartOfLine); Tok.setFlagValue(Token::LeadingSpace, HasLeadingSpace); Tok.clearFlag(Token::NeedsCleaning); diff --git a/clang/unittests/Tooling/Syntax/TokensTest.cpp b/clang/unittests/Tooling/Syntax/TokensTest.cpp index ae5001a2f5645..5efe52a9cbbb9 100644 --- a/clang/unittests/Tooling/Syntax/TokensTest.cpp +++ b/clang/unittests/Tooling/Syntax/TokensTest.cpp @@ -552,6 +552,25 @@ file './input.cpp' } } +TEST_F(TokenCollectorTest, FeatureLikeBuiltinMacros) { + recordTokens("__has_builtin(__builtin_allow_runtime_check)\n"); + EXPECT_THAT(Buffer.expandedTokens(), + ElementsAre(AllOf(Kind(tok::numeric_constant), HasText("1")), + Kind(tok::eof))); + auto ExpansionRange = + SourceMgr->getExpansionRange(findExpanded("1").front().location()); + auto MacroInvocation = + findSpelled("__has_builtin ( __builtin_allow_runtime_check )"); + EXPECT_EQ(MacroInvocation.front().location(), ExpansionRange.getBegin()); + EXPECT_EQ(MacroInvocation.back().location(), ExpansionRange.getEnd()); + + AllowErrors = true; + recordTokens("__is_identifier;\n"); + EXPECT_THAT(Buffer.expandedTokens(), + ElementsAre(AllOf(Kind(tok::numeric_constant), HasText("0")), + Kind(tok::eof))); +} + TEST_F(TokenCollectorTest, SpecialTokens) { // Tokens coming from concatenations. recordTokens(R"cpp( _______________________________________________ cfe-commits mailing list [email protected] https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
