Author: ibiryukov Date: Mon Jul 9 02:07:01 2018 New Revision: 336528 URL: http://llvm.org/viewvc/llvm-project?rev=336528&view=rev Log: [Preamble] Check system dependencies in preamble too
Summary: PrecompiledPreamble hasn't checked if the system dependencies changed before. This resulted in invalid preamble not being rebuilt if headers that changed were found in -isystem include paths. This pattern is sometimes used to avoid showing warnings in third party code, so we want to correctly handle those cases. Tested in clangd, see the follow-up patch. Reviewers: sammccall, ioeric Reviewed By: sammccall Subscribers: omtcyfz, cfe-commits Differential Revision: https://reviews.llvm.org/D48946 Modified: cfe/trunk/lib/Frontend/PrecompiledPreamble.cpp Modified: cfe/trunk/lib/Frontend/PrecompiledPreamble.cpp URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Frontend/PrecompiledPreamble.cpp?rev=336528&r1=336527&r2=336528&view=diff ============================================================================== --- cfe/trunk/lib/Frontend/PrecompiledPreamble.cpp (original) +++ cfe/trunk/lib/Frontend/PrecompiledPreamble.cpp Mon Jul 9 02:07:01 2018 @@ -63,6 +63,16 @@ createVFSOverlayForPreamblePCH(StringRef return Overlay; } +class PreambleDependencyCollector : public DependencyCollector { +public: + // We want to collect all dependencies for correctness. Avoiding the real + // system dependencies (e.g. stl from /usr/lib) would probably be a good idea, + // but there is no way to distinguish between those and the ones that can be + // spuriously added by '-isystem' (e.g. to suppress warnings from those + // headers). + bool needSystemDependencies() override { return true; } +}; + /// Keeps a track of files to be deleted in destructor. class TemporaryFiles { public: @@ -311,7 +321,7 @@ llvm::ErrorOr<PrecompiledPreamble> Preco Clang->setSourceManager( new SourceManager(Diagnostics, Clang->getFileManager())); - auto PreambleDepCollector = std::make_shared<DependencyCollector>(); + auto PreambleDepCollector = std::make_shared<PreambleDependencyCollector>(); Clang->addDependencyCollector(PreambleDepCollector); // Remap the main source file to the preamble buffer. _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
