Author: rsmith Date: Sat Jan 7 22:01:15 2017 New Revision: 291382 URL: http://llvm.org/viewvc/llvm-project?rev=291382&view=rev Log: PR18402: work around bug in libstdc++4.8's detection of whether ::gets exists.
This should allow clang to successfully compile libstdc++4.8's headers in C++14 mode. Added: cfe/trunk/test/SemaCXX/libstdcxx_gets_hack.cpp Modified: cfe/trunk/lib/Sema/SemaDeclCXX.cpp Modified: cfe/trunk/lib/Sema/SemaDeclCXX.cpp URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaDeclCXX.cpp?rev=291382&r1=291381&r2=291382&view=diff ============================================================================== --- cfe/trunk/lib/Sema/SemaDeclCXX.cpp (original) +++ cfe/trunk/lib/Sema/SemaDeclCXX.cpp Sat Jan 7 22:01:15 2017 @@ -9135,6 +9135,16 @@ NamedDecl *Sema::BuildUsingDeclaration(S // invalid). if (R.empty() && NameInfo.getName().getNameKind() != DeclarationName::CXXConstructorName) { + // HACK: Work around a bug in libstdc++'s detection of ::gets. Sometimes + // it will believe that glibc provides a ::gets in cases where it does not, + // and will try to pull it into namespace std with a using-declaration. + // Just ignore the using-declaration in that case. + auto *II = NameInfo.getName().getAsIdentifierInfo(); + if (getLangOpts().CPlusPlus14 && II && II->isStr("gets") && + CurContext->isStdNamespace() && + isa<TranslationUnitDecl>(LookupContext) && + getSourceManager().isInSystemHeader(UsingLoc)) + return nullptr; if (TypoCorrection Corrected = CorrectTypo( R.getLookupNameInfo(), R.getLookupKind(), S, &SS, llvm::make_unique<UsingValidatorCCC>( Added: cfe/trunk/test/SemaCXX/libstdcxx_gets_hack.cpp URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/SemaCXX/libstdcxx_gets_hack.cpp?rev=291382&view=auto ============================================================================== --- cfe/trunk/test/SemaCXX/libstdcxx_gets_hack.cpp (added) +++ cfe/trunk/test/SemaCXX/libstdcxx_gets_hack.cpp Sat Jan 7 22:01:15 2017 @@ -0,0 +1,28 @@ +// RUN: %clang_cc1 -fsyntax-only %s -std=c++14 -verify + +// This is a test for an egregious hack in Clang that works around +// an issue with libstdc++'s detection of whether glibc provides a +// ::gets function. If there is no ::gets, ignore +// using ::gets; +// in namespace std. +// +// See PR18402 and gcc.gnu.org/PR77795 for more details. + +#ifdef BE_THE_HEADER + +#pragma GCC system_header +namespace std { + using ::gets; + using ::getx; // expected-error {{no member named 'getx'}} +} + +#else + +#define BE_THE_HEADER +#include "libstdcxx_pointer_return_false_hack.cpp" + +namespace foo { + using ::gets; // expected-error {{no member named 'gets'}} +} + +#endif _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits