diff --git a/clang/include/clang/Basic/DiagnosticFrontendKinds.td b/clang/include/clang/Basic/DiagnosticFrontendKinds.td --- a/clang/include/clang/Basic/DiagnosticFrontendKinds.td +++ b/clang/include/clang/Basic/DiagnosticFrontendKinds.td @@ -229,6 +229,8 @@ InGroup; def remark_module_build_done : Remark<"finished building module '%0'">, InGroup; +def remark_module_lock : Remark<"locking '%0' to build module '%1'">, + InGroup; def err_modules_embed_file_not_found : Error<"file '%0' specified by '-fmodules-embed-file=' not found">, DefaultFatal; diff --git a/clang/include/clang/Basic/DiagnosticGroups.td b/clang/include/clang/Basic/DiagnosticGroups.td --- a/clang/include/clang/Basic/DiagnosticGroups.td +++ b/clang/include/clang/Basic/DiagnosticGroups.td @@ -465,6 +465,7 @@ def MismatchedReturnTypes : DiagGroup<"mismatched-return-types">; def MismatchedTags : DiagGroup<"mismatched-tags">; def MissingFieldInitializers : DiagGroup<"missing-field-initializers">; +def ModuleLock : DiagGroup<"module-lock">; def ModuleBuild : DiagGroup<"module-build">; def ModuleImport : DiagGroup<"module-import">; def ModuleConflict : DiagGroup<"module-conflict">; diff --git a/clang/include/clang/Driver/Options.td b/clang/include/clang/Driver/Options.td --- a/clang/include/clang/Driver/Options.td +++ b/clang/include/clang/Driver/Options.td @@ -5301,6 +5301,12 @@ HelpText<"Embed the contents of all files read by this compilation into " "the produced module file.">, MarshallingInfoFlag>; +defm fimplicit_modules_use_lock : BoolOption<"f", "implicit-modules-use-lock", + FrontendOpts<"BuildingImplicitModuleUsesLock">, DefaultTrue, + NegFlag, + PosFlag>; // FIXME: We only need this in C++ modules / Modules TS if we might textually // enter a different module (eg, when building a header unit). def fmodules_local_submodule_visibility : diff --git a/clang/include/clang/Frontend/FrontendOptions.h b/clang/include/clang/Frontend/FrontendOptions.h --- a/clang/include/clang/Frontend/FrontendOptions.h +++ b/clang/include/clang/Frontend/FrontendOptions.h @@ -289,6 +289,9 @@ /// Whether we are performing an implicit module build. unsigned BuildingImplicitModule : 1; + /// Whether to use a filesystem lock when building implicit modules. + unsigned BuildingImplicitModuleUsesLock : 1; + /// Whether we should embed all used files into the PCM file. unsigned ModulesEmbedAllFiles : 1; @@ -461,9 +464,9 @@ SkipFunctionBodies(false), UseGlobalModuleIndex(true), GenerateGlobalModuleIndex(true), ASTDumpDecls(false), ASTDumpLookups(false), BuildingImplicitModule(false), - ModulesEmbedAllFiles(false), IncludeTimestamps(true), - UseTemporary(true), AllowPCMWithCompilerErrors(false), - TimeTraceGranularity(500) {} + BuildingImplicitModuleUsesLock(true), ModulesEmbedAllFiles(false), + IncludeTimestamps(true), UseTemporary(true), + AllowPCMWithCompilerErrors(false), TimeTraceGranularity(500) {} /// getInputKindForExtension - Return the appropriate input kind for a file /// extension. For example, "c" would return Language::C. diff --git a/clang/lib/Frontend/CompilerInstance.cpp b/clang/lib/Frontend/CompilerInstance.cpp --- a/clang/lib/Frontend/CompilerInstance.cpp +++ b/clang/lib/Frontend/CompilerInstance.cpp @@ -1331,6 +1331,9 @@ SourceLocation ModuleNameLoc, Module *Module, StringRef ModuleFileName) { DiagnosticsEngine &Diags = ImportingInstance.getDiagnostics(); + Diags.Report(ModuleNameLoc, diag::remark_module_lock) + << ModuleFileName << Module->Name; + // FIXME: have LockFileManager return an error_code so that we can // avoid the mkdir when the directory already exists. StringRef Dir = llvm::sys::path::parent_path(ModuleFileName); @@ -1389,6 +1392,25 @@ } } +/// Compile a module in a separate compiler instance and read the AST, +/// returning true if the module compiles without errors, potentially using a +/// lock manager to avoid building the same module in multiple compiler +/// instances. +static bool compileModuleAndReadAST(CompilerInstance &ImportingInstance, + SourceLocation ImportLoc, + SourceLocation ModuleNameLoc, + Module *Module, StringRef ModuleFileName) { + return ImportingInstance.getInvocation() + .getFrontendOpts() + .BuildingImplicitModuleUsesLock + ? compileModuleAndReadASTBehindLock(ImportingInstance, ImportLoc, + ModuleNameLoc, Module, + ModuleFileName) + : compileModuleAndReadASTImpl(ImportingInstance, ImportLoc, + ModuleNameLoc, Module, + ModuleFileName); +} + /// Diagnose differences between the current definition of the given /// configuration macro and the definition provided on the command line. static void checkConfigMacro(Preprocessor &PP, StringRef ConfigMacro, @@ -1866,8 +1888,8 @@ } // Try to compile and then read the AST. - if (!compileModuleAndReadASTBehindLock(*this, ImportLoc, ModuleNameLoc, M, - ModuleFilename)) { + if (!compileModuleAndReadAST(*this, ImportLoc, ModuleNameLoc, M, + ModuleFilename)) { assert(getDiagnostics().hasErrorOccurred() && "undiagnosed error in compileModuleAndReadAST"); if (getPreprocessorOpts().FailedModules) diff --git a/clang/test/Modules/implicit-modules-use-lock.m b/clang/test/Modules/implicit-modules-use-lock.m new file mode 100644 --- /dev/null +++ b/clang/test/Modules/implicit-modules-use-lock.m @@ -0,0 +1,23 @@ +// Confirm -fimplicit-modules-use-lock and -fno-implicit-modules-use-lock control +// whether building a module triggers -Rmodule-lock, indirectly checking whether +// a lock manager is being used. +// +// RUN: rm -rf %t.cache +// RUN: %clang_cc1 -fmodules -fimplicit-module-maps \ +// RUN: -fimplicit-modules-use-lock -Rmodule-lock \ +// RUN: -fmodules-cache-path=%t.cache -I%S/Inputs/system-out-of-date \ +// RUN: -fsyntax-only %s -Wnon-modular-include-in-framework-module \ +// RUN: -Werror=non-modular-include-in-framework-module 2>&1 \ +// RUN: | FileCheck %s -check-prefix=CHECK-LOCKS +// +// RUN: rm -rf %t.cache +// RUN: %clang_cc1 -fmodules -fimplicit-module-maps \ +// RUN: -fno-implicit-modules-use-lock -Rmodule-lock \ +// RUN: -fmodules-cache-path=%t.cache -I%S/Inputs/system-out-of-date \ +// RUN: -fsyntax-only %s -Wnon-modular-include-in-framework-module \ +// RUN: -Werror=non-modular-include-in-framework-module 2>&1 \ +// RUN: | FileCheck %s -check-prefix=CHECK-NO-LOCKS -allow-empty + +// CHECK-NO-LOCKS-NOT: remark: +// CHECK-LOCKS: remark: locking '{{.*}}.pcm' to build module 'X' [-Rmodule-lock] +@import X;