Author: ibiryukov Date: Mon Jul 9 04:33:23 2018 New Revision: 336539 URL: http://llvm.org/viewvc/llvm-project?rev=336539&view=rev Log: [PCH] Add an option to not write comments into PCH
Summary: Will be used in clangd, see the follow-up change. Clangd does not use comments read from PCH to avoid crashes due to changed contents of the file. However, reading them considerably slows down code completion on files with large preambles. Reviewers: sammccall Reviewed By: sammccall Subscribers: ioeric, cfe-commits Differential Revision: https://reviews.llvm.org/D48942 Modified: cfe/trunk/include/clang/Lex/PreprocessorOptions.h cfe/trunk/lib/Serialization/ASTWriter.cpp Modified: cfe/trunk/include/clang/Lex/PreprocessorOptions.h URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/Lex/PreprocessorOptions.h?rev=336539&r1=336538&r2=336539&view=diff ============================================================================== --- cfe/trunk/include/clang/Lex/PreprocessorOptions.h (original) +++ cfe/trunk/include/clang/Lex/PreprocessorOptions.h Mon Jul 9 04:33:23 2018 @@ -95,6 +95,11 @@ public: /// processing the rest of the file. bool GeneratePreamble = false; + /// Whether to write comment locations into the PCH when building it. + /// Reading the comments from the PCH can be a performance hit even if the + /// clients don't use them. + bool WriteCommentListToPCH = true; + /// The implicit PTH input included at the start of the translation unit, or /// empty. std::string ImplicitPTHInclude; Modified: cfe/trunk/lib/Serialization/ASTWriter.cpp URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Serialization/ASTWriter.cpp?rev=336539&r1=336538&r2=336539&view=diff ============================================================================== --- cfe/trunk/lib/Serialization/ASTWriter.cpp (original) +++ cfe/trunk/lib/Serialization/ASTWriter.cpp Mon Jul 9 04:33:23 2018 @@ -78,6 +78,7 @@ #include "llvm/ADT/Optional.h" #include "llvm/ADT/PointerIntPair.h" #include "llvm/ADT/STLExtras.h" +#include "llvm/ADT/ScopeExit.h" #include "llvm/ADT/SmallSet.h" #include "llvm/ADT/SmallString.h" #include "llvm/ADT/SmallVector.h" @@ -3252,6 +3253,9 @@ void ASTWriter::WriteFileDeclIDsMap() { void ASTWriter::WriteComments() { Stream.EnterSubblock(COMMENTS_BLOCK_ID, 3); + auto _ = llvm::make_scope_exit([this] { Stream.ExitBlock(); }); + if (!PP->getPreprocessorOpts().WriteCommentListToPCH) + return; ArrayRef<RawComment *> RawComments = Context->Comments.getComments(); RecordData Record; for (const auto *I : RawComments) { @@ -3262,7 +3266,6 @@ void ASTWriter::WriteComments() { Record.push_back(I->isAlmostTrailingComment()); Stream.EmitRecord(COMMENTS_RAW_COMMENT, Record); } - Stream.ExitBlock(); } //===----------------------------------------------------------------------===// _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
