Author: ssrivastava Date: Mon Jul 25 12:17:06 2016 New Revision: 276653 URL: http://llvm.org/viewvc/llvm-project?rev=276653&view=rev Log: Support '#pragma once' in headers when using PCH The '#pragma once' directive was erroneously ignored when encountered in the header-file specified in generate-PCH-mode. This resulted in compile-time errors in some cases with legal code, and also a misleading warning being produced.
Patch by Warren Ristow! Differential Revision: http://reviews.llvm.org/D19815 Added: cfe/trunk/test/PCH/Inputs/pragma-once.h cfe/trunk/test/PCH/pragma-once.c Modified: cfe/trunk/lib/Lex/Pragma.cpp Modified: cfe/trunk/lib/Lex/Pragma.cpp URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Lex/Pragma.cpp?rev=276653&r1=276652&r2=276653&view=diff ============================================================================== --- cfe/trunk/lib/Lex/Pragma.cpp (original) +++ cfe/trunk/lib/Lex/Pragma.cpp Mon Jul 25 12:17:06 2016 @@ -352,7 +352,9 @@ void Preprocessor::HandleMicrosoft__prag /// HandlePragmaOnce - Handle \#pragma once. OnceTok is the 'once'. /// void Preprocessor::HandlePragmaOnce(Token &OnceTok) { - if (isInPrimaryFile()) { + // Don't honor the 'once' when handling the primary source file, unless + // this is a prefix to a TU, which indicates we're generating a PCH file. + if (isInPrimaryFile() && TUKind != TU_Prefix) { Diag(OnceTok, diag::pp_pragma_once_in_main_file); return; } Added: cfe/trunk/test/PCH/Inputs/pragma-once.h URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/PCH/Inputs/pragma-once.h?rev=276653&view=auto ============================================================================== --- cfe/trunk/test/PCH/Inputs/pragma-once.h (added) +++ cfe/trunk/test/PCH/Inputs/pragma-once.h Mon Jul 25 12:17:06 2016 @@ -0,0 +1,5 @@ +#pragma once + +/* For use with the pragma-once.c test */ + +int x = 3; Added: cfe/trunk/test/PCH/pragma-once.c URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/PCH/pragma-once.c?rev=276653&view=auto ============================================================================== --- cfe/trunk/test/PCH/pragma-once.c (added) +++ cfe/trunk/test/PCH/pragma-once.c Mon Jul 25 12:17:06 2016 @@ -0,0 +1,13 @@ +// Test this without pch. +// RUN: %clang_cc1 -include %S/Inputs/pragma-once.h -fsyntax-only -verify %s + +// Test with pch. +// RUN: %clang_cc1 -emit-pch -o %t %S/Inputs/pragma-once.h +// RUN: %clang_cc1 -include-pch %t -fsyntax-only -verify %s + +// expected-no-diagnostics + +// Including "pragma-once.h" twice, to verify the 'once' aspect is honored. +#include "Inputs/pragma-once.h" +#include "Inputs/pragma-once.h" +int foo(void) { return 0; } _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
