Author: Luboš Luňák Date: 2020-04-27T21:26:13+02:00 New Revision: 5c8c9905c2496a38a17f1b2a180601e790e45db9
URL: https://github.com/llvm/llvm-project/commit/5c8c9905c2496a38a17f1b2a180601e790e45db9 DIFF: https://github.com/llvm/llvm-project/commit/5c8c9905c2496a38a17f1b2a180601e790e45db9.diff LOG: make sure to not warn about unused macros from -D If a PCH is used for compilation, SourceManager::isInMainFile() returns true even for the "<built-in>" predefines area. Using -D only for the TU compilation may trigger -Wunused-macros for it. It is admitedly a bit fishy to set a macro only for a TU and not for the PCH, but this works fine if the PCH does not use the macro (I couldn't find a statement on this for Clang, but GCC explicitly allows this in the docs). Differential Revision: https://reviews.llvm.org/D73846 Added: clang/test/PCH/cli-macro.c Modified: clang/lib/Lex/PPDirectives.cpp Removed: ################################################################################ diff --git a/clang/lib/Lex/PPDirectives.cpp b/clang/lib/Lex/PPDirectives.cpp index d6b6f5695b6c..d8041aef08ac 100644 --- a/clang/lib/Lex/PPDirectives.cpp +++ b/clang/lib/Lex/PPDirectives.cpp @@ -2802,7 +2802,9 @@ void Preprocessor::HandleDefineDirective( // warn-because-unused-macro set. If it gets used it will be removed from set. if (getSourceManager().isInMainFile(MI->getDefinitionLoc()) && !Diags->isIgnored(diag::pp_macro_not_used, MI->getDefinitionLoc()) && - !MacroExpansionInDirectivesOverride) { + !MacroExpansionInDirectivesOverride && + getSourceManager().getFileID(MI->getDefinitionLoc()) != + getPredefinesFileID()) { MI->setIsWarnIfUnused(true); WarnUnusedMacroLocs.insert(MI->getDefinitionLoc()); } diff --git a/clang/test/PCH/cli-macro.c b/clang/test/PCH/cli-macro.c new file mode 100644 index 000000000000..bae8cc3ff0e7 --- /dev/null +++ b/clang/test/PCH/cli-macro.c @@ -0,0 +1,12 @@ +// Test this without pch. +// RUN: %clang_cc1 -Wunused-macros -Dunused=1 -fsyntax-only -verify %s + +// Test with pch. +// RUN: %clang_cc1 -Wunused-macros -emit-pch -o %t %s +// RUN: %clang_cc1 -Wunused-macros -Dunused=1 -include-pch %t -fsyntax-only -verify %s + +// expected-no-diagnostics + +// -Dunused=1 is intentionally not set for the pch. +// There still should be no unused warning for a macro from the command line. + _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits