Index: include/clang/AST/ExternalASTSource.h =================================================================== --- include/clang/AST/ExternalASTSource.h +++ include/clang/AST/ExternalASTSource.h @@ -163,6 +163,10 @@ /// Retrieve the module that corresponds to the given module ID. virtual Module *getModule(unsigned ID) { return nullptr; } + /// Determine whether D comes from a PCH which was built with a corresponding + /// object file. + virtual bool DeclIsFromPCHWithObjectFile(const Decl *D) { return false; } + /// Abstracts clang modules and precompiled header files and holds /// everything needed to generate debug info for an imported module /// or PCH. Index: include/clang/Basic/LangOptions.def =================================================================== --- include/clang/Basic/LangOptions.def +++ include/clang/Basic/LangOptions.def @@ -154,6 +154,7 @@ BENIGN_ENUM_LANGOPT(CompilingModule, CompilingModuleKind, 2, CMK_None, "compiling a module interface") BENIGN_LANGOPT(CompilingPCH, 1, 0, "building a pch") +BENIGN_LANGOPT(BuildingPCHWithObjectFile, 1, 0, "building a pch which has a corresponding object file") COMPATIBLE_LANGOPT(ModulesDeclUse , 1, 0, "require declaration of module uses") BENIGN_LANGOPT(ModulesSearchAll , 1, 1, "searching even non-imported modules to find unresolved references") COMPATIBLE_LANGOPT(ModulesStrictDeclUse, 1, 0, "requiring declaration of module uses and all headers to be in modules") Index: include/clang/Driver/CC1Options.td =================================================================== --- include/clang/Driver/CC1Options.td +++ include/clang/Driver/CC1Options.td @@ -609,7 +609,9 @@ "to this flag.">; def fno_pch_timestamp : Flag<["-"], "fno-pch-timestamp">, HelpText<"Disable inclusion of timestamp in precompiled headers">; - +def building_pch_with_obj : Flag<["-"], "building-pch-with-obj">, + HelpText<"This compilation is part of building a PCH with corresponding object file.">; + def aligned_alloc_unavailable : Flag<["-"], "faligned-alloc-unavailable">, HelpText<"Aligned allocation/deallocation functions are unavailable">; Index: include/clang/Sema/MultiplexExternalSemaSource.h =================================================================== --- include/clang/Sema/MultiplexExternalSemaSource.h +++ include/clang/Sema/MultiplexExternalSemaSource.h @@ -152,6 +152,8 @@ /// Retrieve the module that corresponds to the given module ID. Module *getModule(unsigned ID) override; + bool DeclIsFromPCHWithObjectFile(const Decl *D) override; + /// Perform layout on the given record. /// /// This routine allows the external AST source to provide an specific Index: include/clang/Serialization/ASTBitCodes.h =================================================================== --- include/clang/Serialization/ASTBitCodes.h +++ include/clang/Serialization/ASTBitCodes.h @@ -42,7 +42,7 @@ /// Version 4 of AST files also requires that the version control branch and /// revision match exactly, since there is no backward compatibility of /// AST files at this time. - const unsigned VERSION_MAJOR = 6; + const unsigned VERSION_MAJOR = 7; /// AST file minor version number supported by this version of /// Clang. Index: include/clang/Serialization/ASTReader.h =================================================================== --- include/clang/Serialization/ASTReader.h +++ include/clang/Serialization/ASTReader.h @@ -2071,6 +2071,8 @@ /// Note: overrides method in ExternalASTSource Module *getModule(unsigned ID) override; + bool DeclIsFromPCHWithObjectFile(const Decl *D) override; + /// Retrieve the module file with a given local ID within the specified /// ModuleFile. ModuleFile *getLocalModuleFile(ModuleFile &M, unsigned ID); Index: include/clang/Serialization/Module.h =================================================================== --- include/clang/Serialization/Module.h +++ include/clang/Serialization/Module.h @@ -157,6 +157,9 @@ /// Whether timestamps are included in this module file. bool HasTimestamps = false; + /// Whether the PCH has a corresponding object file. + bool PCHHasObjectFile = false; + /// The file entry for the module file. const FileEntry *File = nullptr; Index: lib/AST/ASTContext.cpp =================================================================== --- lib/AST/ASTContext.cpp +++ lib/AST/ASTContext.cpp @@ -9553,6 +9553,19 @@ else return false; + if (D->isFromASTFile() && !LangOpts.BuildingPCHWithObjectFile) { + assert(getExternalSource() && "It's from an AST file; must have a source."); + // On Windows, PCH files are built together with an object file. If this + // declaration comes from such a PCH and DeclMustBeEmitted would return + // true, it would have returned true and the decl would have been emitted + // into that object file, so it doesn't need to be emitted here. + // Note that decls are still emitted if they're referenced, as usual; + // DeclMustBeEmitted is used to decide whether a decl must be emitted even + // if it's not referenced. + if (getExternalSource()->DeclIsFromPCHWithObjectFile(D)) + return false; + } + // If this is a member of a class template, we do not need to emit it. if (D->getDeclContext()->isDependentContext()) return false; @@ -9573,7 +9586,7 @@ // Constructors and destructors are required. if (FD->hasAttr() || FD->hasAttr()) return true; - + // The key function for a class is required. This rule only comes // into play when inline functions can be key functions, though. if (getTargetInfo().getCXXABI().canKeyFunctionBeInline()) { @@ -9594,7 +9607,7 @@ // Implicit template instantiations can also be deferred in C++. return !isDiscardableGVALinkage(Linkage); } - + const auto *VD = cast(D); assert(VD->isFileVarDecl() && "Expected file scoped var"); Index: lib/Driver/Driver.cpp =================================================================== --- lib/Driver/Driver.cpp +++ lib/Driver/Driver.cpp @@ -3088,6 +3088,8 @@ // The driver currently exits after the first failed command. This // relies on that behavior, to make sure if the pch generation fails, // the main compilation won't run. + // FIXME: If the main compilation fails, the PCH generation should + // probably not be considered successful either. } } Index: lib/Driver/ToolChains/Clang.cpp =================================================================== --- lib/Driver/ToolChains/Clang.cpp +++ lib/Driver/ToolChains/Clang.cpp @@ -1084,6 +1084,10 @@ CmdArgs.push_back(Args.MakeArgString(Twine("-find-pch-source=") + Inputs[0].second->getValue())); } + if (YcIndex != -1 && JA.getKind() >= Action::PrecompileJobClass && + JA.getKind() <= Action::AssembleJobClass) { + CmdArgs.push_back(Args.MakeArgString("-building-pch-with-obj")); + } bool RenderedImplicitInclude = false; int AI = -1; Index: lib/Frontend/CompilerInvocation.cpp =================================================================== --- lib/Frontend/CompilerInvocation.cpp +++ lib/Frontend/CompilerInvocation.cpp @@ -2772,6 +2772,7 @@ } Opts.CompleteMemberPointers = Args.hasArg(OPT_fcomplete_member_pointers); + Opts.BuildingPCHWithObjectFile = Args.hasArg(OPT_building_pch_with_obj); } static bool isStrictlyPreprocessorAction(frontend::ActionKind Action) { Index: lib/Frontend/FrontendActions.cpp =================================================================== --- lib/Frontend/FrontendActions.cpp +++ lib/Frontend/FrontendActions.cpp @@ -112,14 +112,14 @@ if (!CI.getFrontendOpts().RelocatablePCH) Sysroot.clear(); + const auto &FrontendOpts = CI.getFrontendOpts(); auto Buffer = std::make_shared(); std::vector> Consumers; Consumers.push_back(llvm::make_unique( CI.getPreprocessor(), OutputFile, Sysroot, - Buffer, CI.getFrontendOpts().ModuleFileExtensions, - /*AllowASTWithErrors*/CI.getPreprocessorOpts().AllowPCHWithCompilerErrors, - /*IncludeTimestamps*/ - +CI.getFrontendOpts().IncludeTimestamps)); + Buffer, FrontendOpts.ModuleFileExtensions, + CI.getPreprocessorOpts().AllowPCHWithCompilerErrors, + FrontendOpts.IncludeTimestamps)); Consumers.push_back(CI.getPCHContainerWriter().CreatePCHContainerGenerator( CI, InFile, OutputFile, std::move(OS), Buffer)); Index: lib/Sema/MultiplexExternalSemaSource.cpp =================================================================== --- lib/Sema/MultiplexExternalSemaSource.cpp +++ lib/Sema/MultiplexExternalSemaSource.cpp @@ -171,6 +171,13 @@ return nullptr; } +bool MultiplexExternalSemaSource::DeclIsFromPCHWithObjectFile(const Decl *D) { + for (auto *S : Sources) + if (S->DeclIsFromPCHWithObjectFile(D)) + return true; + return false; +} + bool MultiplexExternalSemaSource::layoutRecordType(const RecordDecl *Record, uint64_t &Size, uint64_t &Alignment, Index: lib/Serialization/ASTReader.cpp =================================================================== --- lib/Serialization/ASTReader.cpp +++ lib/Serialization/ASTReader.cpp @@ -2482,7 +2482,7 @@ return VersionMismatch; } - bool hasErrors = Record[6]; + bool hasErrors = Record[7]; if (hasErrors && !DisableValidation && !AllowASTWithCompilerErrors) { Diag(diag::err_pch_with_compiler_errors); return HadErrors; @@ -2500,6 +2500,8 @@ F.HasTimestamps = Record[5]; + F.PCHHasObjectFile = Record[6]; + const std::string &CurBranch = getClangFullRepositoryVersion(); StringRef ASTBranch = Blob; if (StringRef(CurBranch) != ASTBranch && !DisableValidation) { @@ -8448,6 +8450,11 @@ return getSubmodule(ID); } +bool ASTReader::DeclIsFromPCHWithObjectFile(const Decl *D) { + ModuleFile *MF = getOwningModuleFile(D); + return MF && MF->PCHHasObjectFile; +} + ModuleFile *ASTReader::getLocalModuleFile(ModuleFile &F, unsigned ID) { if (ID & 1) { // It's a module, look it up by submodule ID. Index: lib/Serialization/ASTWriter.cpp =================================================================== --- lib/Serialization/ASTWriter.cpp +++ lib/Serialization/ASTWriter.cpp @@ -1458,16 +1458,23 @@ MetadataAbbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 16)); // Clang min. MetadataAbbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // Relocatable MetadataAbbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // Timestamps + MetadataAbbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // PCHHasObjectFile MetadataAbbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // Errors MetadataAbbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // SVN branch/tag unsigned MetadataAbbrevCode = Stream.EmitAbbrev(std::move(MetadataAbbrev)); assert((!WritingModule || isysroot.empty()) && "writing module as a relocatable PCH?"); { - RecordData::value_type Record[] = {METADATA, VERSION_MAJOR, VERSION_MINOR, - CLANG_VERSION_MAJOR, CLANG_VERSION_MINOR, - !isysroot.empty(), IncludeTimestamps, - ASTHasCompilerErrors}; + RecordData::value_type Record[] = { + METADATA, + VERSION_MAJOR, + VERSION_MINOR, + CLANG_VERSION_MAJOR, + CLANG_VERSION_MINOR, + !isysroot.empty(), + IncludeTimestamps, + Context.getLangOpts().BuildingPCHWithObjectFile, + ASTHasCompilerErrors}; Stream.EmitRecordWithBlob(MetadataAbbrevCode, Record, getClangFullRepositoryVersion()); } Index: test/CodeGen/pch-dllexport.cpp =================================================================== --- /dev/null +++ test/CodeGen/pch-dllexport.cpp @@ -0,0 +1,43 @@ +// Build PCH without object file, then use it. +// RUN: %clang_cc1 -triple i686-pc-win32 -fms-extensions -emit-pch -o %t %s +// RUN: %clang_cc1 -triple i686-pc-win32 -fms-extensions -emit-obj -emit-llvm -include-pch %t -o - %s | FileCheck -check-prefix=PCH %s + +// Build PCH with object file, then use it. +// RUN: %clang_cc1 -triple i686-pc-win32 -fms-extensions -emit-pch -building-pch-with-obj -o %t %s +// RUN: %clang_cc1 -triple i686-pc-win32 -fms-extensions -emit-obj -emit-llvm -include-pch %t -building-pch-with-obj -o - %s | FileCheck -check-prefix=OBJ %s +// RUN: %clang_cc1 -triple i686-pc-win32 -fms-extensions -emit-obj -emit-llvm -include-pch %t -o - %s | FileCheck -check-prefix=PCHWITHOBJ %s + +#ifndef IN_HEADER +#define IN_HEADER + +inline void __declspec(dllexport) foo() {} +// OBJ: define weak_odr dso_local dllexport void @"?foo@@YAXXZ" +// PCH: define weak_odr dso_local dllexport void @"?foo@@YAXXZ" +// PCHWITHOBJ-NOT: define {{.*}}foo + + +// This function is referenced, so gets emitted as usual. +inline void __declspec(dllexport) baz() {} +// OBJ: define weak_odr dso_local dllexport void @"?baz@@YAXXZ" +// PCH: define weak_odr dso_local dllexport void @"?baz@@YAXXZ" +// PCHWITHOBJ: define weak_odr dso_local dllexport void @"?baz@@YAXXZ" + + +struct __declspec(dllexport) S { + void bar() {} +// OBJ: define weak_odr dso_local dllexport x86_thiscallcc void @"?bar@S@@QAEXXZ" +// PCH: define weak_odr dso_local dllexport x86_thiscallcc void @"?bar@S@@QAEXXZ" +// PCHWITHOBJ-NOT: define {{.*}}bar +}; + +// This isn't dllexported, attribute((used)) or referenced, so not emitted. +inline void quux() {} +// OBJ-NOT: define {{.*}}quux +// PCH-NOT: define {{.*}}quux +// PCHWITHOBJ-NOT: define {{.*}}quux + +#else + +void use() { baz(); } + +#endif Index: test/Driver/cl-pch.cpp =================================================================== --- test/Driver/cl-pch.cpp +++ test/Driver/cl-pch.cpp @@ -7,6 +7,7 @@ // 1. Build .pch file. // CHECK-YC: cc1 // CHECK-YC: -emit-pch +// CHECK-YC: -building-pch-with-obj // CHECK-YC: -o // CHECK-YC: pchfile.pch // CHECK-YC: -x @@ -14,6 +15,7 @@ // 2. Use .pch file. // CHECK-YC: cc1 // CHECK-YC: -emit-obj +// CHECK-YC: -building-pch-with-obj // CHECK-YC: -include-pch // CHECK-YC: pchfile.pch @@ -24,11 +26,13 @@ // 1. Build .pch file. // CHECK-YCO: cc1 // CHECK-YCO: -emit-pch +// CHECK-YCO: -building-pch-with-obj // CHECK-YCO: -o // CHECK-YCO: pchfile.pch // 2. Use .pch file. // CHECK-YCO: cc1 // CHECK-YCO: -emit-obj +// CHECK-YCO: -building-pch-with-obj // CHECK-YCO: -include-pch // CHECK-YCO: pchfile.pch // CHECK-YCO: -o @@ -46,6 +50,7 @@ // RUN: | FileCheck -check-prefix=CHECK-YU %s // Use .pch file, but don't build it. // CHECK-YU-NOT: -emit-pch +// CHECK-YU-NOT: -building-pch-with-obj // CHECK-YU: cc1 // CHECK-YU: -emit-obj // CHECK-YU: -include-pch @@ -63,6 +68,7 @@ // 1. Build .pch file. // CHECK-YC-YU: cc1 // CHECK-YC-YU: -emit-pch +// CHECK-YC-YU: -building-pch-with-obj // CHECK-YC-YU: -o // CHECK-YC-YU: pchfile.pch // 2. Use .pch file.