From: Richard Smith Date: Thu, 18 Apr 2019 00:57:02 +0000 (+0000) Subject: Split out modules-specific declaration handling from SemaDecl.cpp into a X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=b7bdb8cf33cb8e4a1a940fab823ae7e0ff394e87;p=platform%2Fupstream%2Fllvm.git Split out modules-specific declaration handling from SemaDecl.cpp into a new SemaModule.cpp. llvm-svn: 358633 --- diff --git a/clang/lib/Sema/CMakeLists.txt b/clang/lib/Sema/CMakeLists.txt index 5f20af0..1684e2a 100644 --- a/clang/lib/Sema/CMakeLists.txt +++ b/clang/lib/Sema/CMakeLists.txt @@ -43,6 +43,7 @@ add_clang_library(clangSema SemaInit.cpp SemaLambda.cpp SemaLookup.cpp + SemaModule.cpp SemaObjCProperty.cpp SemaOpenMP.cpp SemaOverload.cpp diff --git a/clang/lib/Sema/SemaDecl.cpp b/clang/lib/Sema/SemaDecl.cpp index 8e0badf..1969c11 100644 --- a/clang/lib/Sema/SemaDecl.cpp +++ b/clang/lib/Sema/SemaDecl.cpp @@ -17007,471 +17007,6 @@ Decl *Sema::ActOnFileScopeAsmDecl(Expr *expr, return New; } -static void checkModuleImportContext(Sema &S, Module *M, - SourceLocation ImportLoc, DeclContext *DC, - bool FromInclude = false) { - SourceLocation ExternCLoc; - - if (auto *LSD = dyn_cast(DC)) { - switch (LSD->getLanguage()) { - case LinkageSpecDecl::lang_c: - if (ExternCLoc.isInvalid()) - ExternCLoc = LSD->getBeginLoc(); - break; - case LinkageSpecDecl::lang_cxx: - break; - } - DC = LSD->getParent(); - } - - while (isa(DC) || isa(DC)) - DC = DC->getParent(); - - if (!isa(DC)) { - S.Diag(ImportLoc, (FromInclude && S.isModuleVisible(M)) - ? diag::ext_module_import_not_at_top_level_noop - : diag::err_module_import_not_at_top_level_fatal) - << M->getFullModuleName() << DC; - S.Diag(cast(DC)->getBeginLoc(), - diag::note_module_import_not_at_top_level) - << DC; - } else if (!M->IsExternC && ExternCLoc.isValid()) { - S.Diag(ImportLoc, diag::ext_module_import_in_extern_c) - << M->getFullModuleName(); - S.Diag(ExternCLoc, diag::note_extern_c_begins_here); - } -} - -Sema::DeclGroupPtrTy -Sema::ActOnGlobalModuleFragmentDecl(SourceLocation ModuleLoc) { - if (!ModuleScopes.empty() && - ModuleScopes.back().Module->Kind == Module::GlobalModuleFragment) { - // Under -std=c++2a -fmodules-ts, we can find an explicit 'module;' after - // already implicitly entering the global module fragment. That's OK. - assert(getLangOpts().CPlusPlusModules && getLangOpts().ModulesTS && - "unexpectedly encountered multiple global module fragment decls"); - ModuleScopes.back().BeginLoc = ModuleLoc; - return nullptr; - } - - // We start in the global module; all those declarations are implicitly - // module-private (though they do not have module linkage). - auto &Map = PP.getHeaderSearchInfo().getModuleMap(); - auto *GlobalModule = Map.createGlobalModuleForInterfaceUnit(ModuleLoc); - assert(GlobalModule && "module creation should not fail"); - - // Enter the scope of the global module. - ModuleScopes.push_back({}); - ModuleScopes.back().BeginLoc = ModuleLoc; - ModuleScopes.back().Module = GlobalModule; - VisibleModules.setVisible(GlobalModule, ModuleLoc); - - // All declarations created from now on are owned by the global module. - auto *TU = Context.getTranslationUnitDecl(); - TU->setModuleOwnershipKind(Decl::ModuleOwnershipKind::Visible); - TU->setLocalOwningModule(GlobalModule); - - // FIXME: Consider creating an explicit representation of this declaration. - return nullptr; -} - -Sema::DeclGroupPtrTy -Sema::ActOnModuleDecl(SourceLocation StartLoc, SourceLocation ModuleLoc, - ModuleDeclKind MDK, ModuleIdPath Path, bool IsFirstDecl) { - assert((getLangOpts().ModulesTS || getLangOpts().CPlusPlusModules) && - "should only have module decl in Modules TS or C++20"); - - // A module implementation unit requires that we are not compiling a module - // of any kind. A module interface unit requires that we are not compiling a - // module map. - switch (getLangOpts().getCompilingModule()) { - case LangOptions::CMK_None: - // It's OK to compile a module interface as a normal translation unit. - break; - - case LangOptions::CMK_ModuleInterface: - if (MDK != ModuleDeclKind::Implementation) - break; - - // We were asked to compile a module interface unit but this is a module - // implementation unit. That indicates the 'export' is missing. - Diag(ModuleLoc, diag::err_module_interface_implementation_mismatch) - << FixItHint::CreateInsertion(ModuleLoc, "export "); - MDK = ModuleDeclKind::Interface; - break; - - case LangOptions::CMK_ModuleMap: - Diag(ModuleLoc, diag::err_module_decl_in_module_map_module); - return nullptr; - - case LangOptions::CMK_HeaderModule: - Diag(ModuleLoc, diag::err_module_decl_in_header_module); - return nullptr; - } - - assert(ModuleScopes.size() <= 1 && "expected to be at global module scope"); - - // FIXME: Most of this work should be done by the preprocessor rather than - // here, in order to support macro import. - - // Only one module-declaration is permitted per source file. - if (!ModuleScopes.empty() && - ModuleScopes.back().Module->Kind == Module::ModuleInterfaceUnit) { - Diag(ModuleLoc, diag::err_module_redeclaration); - Diag(VisibleModules.getImportLoc(ModuleScopes.back().Module), - diag::note_prev_module_declaration); - return nullptr; - } - - // Find the global module fragment we're adopting into this module, if any. - Module *GlobalModuleFragment = nullptr; - if (!ModuleScopes.empty() && - ModuleScopes.back().Module->Kind == Module::GlobalModuleFragment) - GlobalModuleFragment = ModuleScopes.back().Module; - - // In C++20, the module-declaration must be the first declaration if there - // is no global module fragment. - if (getLangOpts().CPlusPlusModules && !IsFirstDecl && !GlobalModuleFragment) { - Diag(ModuleLoc, diag::err_module_decl_not_at_start); - SourceLocation BeginLoc = - ModuleScopes.empty() - ? SourceMgr.getLocForStartOfFile(SourceMgr.getMainFileID()) - : ModuleScopes.back().BeginLoc; - if (BeginLoc.isValid()) { - Diag(BeginLoc, diag::note_global_module_introducer_missing) - << FixItHint::CreateInsertion(BeginLoc, "module;\n"); - } - } - - // Flatten the dots in a module name. Unlike Clang's hierarchical module map - // modules, the dots here are just another character that can appear in a - // module name. - std::string ModuleName; - for (auto &Piece : Path) { - if (!ModuleName.empty()) - ModuleName += "."; - ModuleName += Piece.first->getName(); - } - - // If a module name was explicitly specified on the command line, it must be - // correct. - if (!getLangOpts().CurrentModule.empty() && - getLangOpts().CurrentModule != ModuleName) { - Diag(Path.front().second, diag::err_current_module_name_mismatch) - << SourceRange(Path.front().second, Path.back().second) - << getLangOpts().CurrentModule; - return nullptr; - } - const_cast(getLangOpts()).CurrentModule = ModuleName; - - auto &Map = PP.getHeaderSearchInfo().getModuleMap(); - Module *Mod; - - switch (MDK) { - case ModuleDeclKind::Interface: { - // We can't have parsed or imported a definition of this module or parsed a - // module map defining it already. - if (auto *M = Map.findModule(ModuleName)) { - Diag(Path[0].second, diag::err_module_redefinition) << ModuleName; - if (M->DefinitionLoc.isValid()) - Diag(M->DefinitionLoc, diag::note_prev_module_definition); - else if (const auto *FE = M->getASTFile()) - Diag(M->DefinitionLoc, diag::note_prev_module_definition_from_ast_file) - << FE->getName(); - Mod = M; - break; - } - - // Create a Module for the module that we're defining. - Mod = Map.createModuleForInterfaceUnit(ModuleLoc, ModuleName, - GlobalModuleFragment); - assert(Mod && "module creation should not fail"); - break; - } - - case ModuleDeclKind::Implementation: - std::pair ModuleNameLoc( - PP.getIdentifierInfo(ModuleName), Path[0].second); - Mod = getModuleLoader().loadModule(ModuleLoc, {ModuleNameLoc}, - Module::AllVisible, - /*IsIncludeDirective=*/false); - if (!Mod) { - Diag(ModuleLoc, diag::err_module_not_defined) << ModuleName; - // Create an empty module interface unit for error recovery. - Mod = Map.createModuleForInterfaceUnit(ModuleLoc, ModuleName, - GlobalModuleFragment); - } - break; - } - - if (!GlobalModuleFragment) { - ModuleScopes.push_back({}); - if (getLangOpts().ModulesLocalVisibility) - ModuleScopes.back().OuterVisibleModules = std::move(VisibleModules); - } - - // Switch from the global module fragment (if any) to the named module. - ModuleScopes.back().BeginLoc = StartLoc; - ModuleScopes.back().Module = Mod; - ModuleScopes.back().ModuleInterface = MDK != ModuleDeclKind::Implementation; - VisibleModules.setVisible(Mod, ModuleLoc); - - // From now on, we have an owning module for all declarations we see. - // However, those declarations are module-private unless explicitly - // exported. - auto *TU = Context.getTranslationUnitDecl(); - TU->setModuleOwnershipKind(Decl::ModuleOwnershipKind::ModulePrivate); - TU->setLocalOwningModule(Mod); - - // FIXME: Create a ModuleDecl. - return nullptr; -} - -DeclResult Sema::ActOnModuleImport(SourceLocation StartLoc, - SourceLocation ExportLoc, - SourceLocation ImportLoc, - ModuleIdPath Path) { - // Flatten the module path for a Modules TS module name. - std::pair ModuleNameLoc; - if (getLangOpts().ModulesTS) { - std::string ModuleName; - for (auto &Piece : Path) { - if (!ModuleName.empty()) - ModuleName += "."; - ModuleName += Piece.first->getName(); - } - ModuleNameLoc = {PP.getIdentifierInfo(ModuleName), Path[0].second}; - Path = ModuleIdPath(ModuleNameLoc); - } - - Module *Mod = - getModuleLoader().loadModule(ImportLoc, Path, Module::AllVisible, - /*IsIncludeDirective=*/false); - if (!Mod) - return true; - - return ActOnModuleImport(StartLoc, ExportLoc, ImportLoc, Mod, Path); -} - -DeclResult Sema::ActOnModuleImport(SourceLocation StartLoc, - SourceLocation ExportLoc, - SourceLocation ImportLoc, - Module *Mod, ModuleIdPath Path) { - VisibleModules.setVisible(Mod, ImportLoc); - - checkModuleImportContext(*this, Mod, ImportLoc, CurContext); - - // FIXME: we should support importing a submodule within a different submodule - // of the same top-level module. Until we do, make it an error rather than - // silently ignoring the import. - // Import-from-implementation is valid in the Modules TS. FIXME: Should we - // warn on a redundant import of the current module? - // FIXME: Import of a module from an implementation partition of the same - // module is permitted. - if (Mod->getTopLevelModuleName() == getLangOpts().CurrentModule && - (getLangOpts().isCompilingModule() || !getLangOpts().ModulesTS)) { - Diag(ImportLoc, getLangOpts().isCompilingModule() - ? diag::err_module_self_import - : diag::err_module_import_in_implementation) - << Mod->getFullModuleName() << getLangOpts().CurrentModule; - } - - SmallVector IdentifierLocs; - Module *ModCheck = Mod; - for (unsigned I = 0, N = Path.size(); I != N; ++I) { - // If we've run out of module parents, just drop the remaining identifiers. - // We need the length to be consistent. - if (!ModCheck) - break; - ModCheck = ModCheck->Parent; - - IdentifierLocs.push_back(Path[I].second); - } - - // If this was a header import, pad out with dummy locations. - // FIXME: Pass in and use the location of the header-name token in this case. - if (Path.empty()) { - for (; ModCheck; ModCheck = ModCheck->Parent) { - IdentifierLocs.push_back(SourceLocation()); - } - } - - ImportDecl *Import = ImportDecl::Create(Context, CurContext, StartLoc, - Mod, IdentifierLocs); - CurContext->addDecl(Import); - - // Sequence initialization of the imported module before that of the current - // module, if any. - if (!ModuleScopes.empty()) - Context.addModuleInitializer(ModuleScopes.back().Module, Import); - - // Re-export the module if needed. - if (!ModuleScopes.empty() && ModuleScopes.back().ModuleInterface) { - if (ExportLoc.isValid() || Import->isExported()) - getCurrentModule()->Exports.emplace_back(Mod, false); - } else if (ExportLoc.isValid()) { - Diag(ExportLoc, diag::err_export_not_in_module_interface); - } - - return Import; -} - -void Sema::ActOnModuleInclude(SourceLocation DirectiveLoc, Module *Mod) { - checkModuleImportContext(*this, Mod, DirectiveLoc, CurContext, true); - BuildModuleInclude(DirectiveLoc, Mod); -} - -void Sema::BuildModuleInclude(SourceLocation DirectiveLoc, Module *Mod) { - // Determine whether we're in the #include buffer for a module. The #includes - // in that buffer do not qualify as module imports; they're just an - // implementation detail of us building the module. - // - // FIXME: Should we even get ActOnModuleInclude calls for those? - bool IsInModuleIncludes = - TUKind == TU_Module && - getSourceManager().isWrittenInMainFile(DirectiveLoc); - - bool ShouldAddImport = !IsInModuleIncludes; - - // If this module import was due to an inclusion directive, create an - // implicit import declaration to capture it in the AST. - if (ShouldAddImport) { - TranslationUnitDecl *TU = getASTContext().getTranslationUnitDecl(); - ImportDecl *ImportD = ImportDecl::CreateImplicit(getASTContext(), TU, - DirectiveLoc, Mod, - DirectiveLoc); - if (!ModuleScopes.empty()) - Context.addModuleInitializer(ModuleScopes.back().Module, ImportD); - TU->addDecl(ImportD); - Consumer.HandleImplicitImportDecl(ImportD); - } - - getModuleLoader().makeModuleVisible(Mod, Module::AllVisible, DirectiveLoc); - VisibleModules.setVisible(Mod, DirectiveLoc); -} - -void Sema::ActOnModuleBegin(SourceLocation DirectiveLoc, Module *Mod) { - checkModuleImportContext(*this, Mod, DirectiveLoc, CurContext, true); - - ModuleScopes.push_back({}); - ModuleScopes.back().Module = Mod; - if (getLangOpts().ModulesLocalVisibility) - ModuleScopes.back().OuterVisibleModules = std::move(VisibleModules); - - VisibleModules.setVisible(Mod, DirectiveLoc); - - // The enclosing context is now part of this module. - // FIXME: Consider creating a child DeclContext to hold the entities - // lexically within the module. - if (getLangOpts().trackLocalOwningModule()) { - for (auto *DC = CurContext; DC; DC = DC->getLexicalParent()) { - cast(DC)->setModuleOwnershipKind( - getLangOpts().ModulesLocalVisibility - ? Decl::ModuleOwnershipKind::VisibleWhenImported - : Decl::ModuleOwnershipKind::Visible); - cast(DC)->setLocalOwningModule(Mod); - } - } -} - -void Sema::ActOnModuleEnd(SourceLocation EomLoc, Module *Mod) { - if (getLangOpts().ModulesLocalVisibility) { - VisibleModules = std::move(ModuleScopes.back().OuterVisibleModules); - // Leaving a module hides namespace names, so our visible namespace cache - // is now out of date. - VisibleNamespaceCache.clear(); - } - - assert(!ModuleScopes.empty() && ModuleScopes.back().Module == Mod && - "left the wrong module scope"); - ModuleScopes.pop_back(); - - // We got to the end of processing a local module. Create an - // ImportDecl as we would for an imported module. - FileID File = getSourceManager().getFileID(EomLoc); - SourceLocation DirectiveLoc; - if (EomLoc == getSourceManager().getLocForEndOfFile(File)) { - // We reached the end of a #included module header. Use the #include loc. - assert(File != getSourceManager().getMainFileID() && - "end of submodule in main source file"); - DirectiveLoc = getSourceManager().getIncludeLoc(File); - } else { - // We reached an EOM pragma. Use the pragma location. - DirectiveLoc = EomLoc; - } - BuildModuleInclude(DirectiveLoc, Mod); - - // Any further declarations are in whatever module we returned to. - if (getLangOpts().trackLocalOwningModule()) { - // The parser guarantees that this is the same context that we entered - // the module within. - for (auto *DC = CurContext; DC; DC = DC->getLexicalParent()) { - cast(DC)->setLocalOwningModule(getCurrentModule()); - if (!getCurrentModule()) - cast(DC)->setModuleOwnershipKind( - Decl::ModuleOwnershipKind::Unowned); - } - } -} - -void Sema::createImplicitModuleImportForErrorRecovery(SourceLocation Loc, - Module *Mod) { - // Bail if we're not allowed to implicitly import a module here. - if (isSFINAEContext() || !getLangOpts().ModulesErrorRecovery || - VisibleModules.isVisible(Mod)) - return; - - // Create the implicit import declaration. - TranslationUnitDecl *TU = getASTContext().getTranslationUnitDecl(); - ImportDecl *ImportD = ImportDecl::CreateImplicit(getASTContext(), TU, - Loc, Mod, Loc); - TU->addDecl(ImportD); - Consumer.HandleImplicitImportDecl(ImportD); - - // Make the module visible. - getModuleLoader().makeModuleVisible(Mod, Module::AllVisible, Loc); - VisibleModules.setVisible(Mod, Loc); -} - -/// We have parsed the start of an export declaration, including the '{' -/// (if present). -Decl *Sema::ActOnStartExportDecl(Scope *S, SourceLocation ExportLoc, - SourceLocation LBraceLoc) { - ExportDecl *D = ExportDecl::Create(Context, CurContext, ExportLoc); - - // C++ Modules TS draft: - // An export-declaration shall appear in the purview of a module other than - // the global module. - if (ModuleScopes.empty() || !ModuleScopes.back().ModuleInterface) - Diag(ExportLoc, diag::err_export_not_in_module_interface); - - // An export-declaration [...] shall not contain more than one - // export keyword. - // - // The intent here is that an export-declaration cannot appear within another - // export-declaration. - if (D->isExported()) - Diag(ExportLoc, diag::err_export_within_export); - - CurContext->addDecl(D); - PushDeclContext(S, D); - D->setModuleOwnershipKind(Decl::ModuleOwnershipKind::VisibleWhenImported); - return D; -} - -/// Complete the definition of an export declaration. -Decl *Sema::ActOnFinishExportDecl(Scope *S, Decl *D, SourceLocation RBraceLoc) { - auto *ED = cast(D); - if (RBraceLoc.isValid()) - ED->setRBraceLoc(RBraceLoc); - - // FIXME: Diagnose export of internal-linkage declaration (including - // anonymous namespace). - - PopDeclContext(); - return D; -} - void Sema::ActOnPragmaRedefineExtname(IdentifierInfo* Name, IdentifierInfo* AliasName, SourceLocation PragmaLoc, diff --git a/clang/lib/Sema/SemaModule.cpp b/clang/lib/Sema/SemaModule.cpp new file mode 100644 index 0000000..e0439b0 --- /dev/null +++ b/clang/lib/Sema/SemaModule.cpp @@ -0,0 +1,485 @@ +//===--- SemaModule.cpp - Semantic Analysis for Modules -------------------===// +// +// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. +// See https://llvm.org/LICENSE.txt for license information. +// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception +// +//===----------------------------------------------------------------------===// +// +// This file implements semantic analysis for modules (C++ modules syntax, +// Objective-C modules syntax, and Clang header modules). +// +//===----------------------------------------------------------------------===// + +#include "clang/AST/ASTConsumer.h" +#include "clang/Lex/HeaderSearch.h" +#include "clang/Lex/Preprocessor.h" +#include "clang/Sema/SemaInternal.h" + +using namespace clang; +using namespace sema; + +static void checkModuleImportContext(Sema &S, Module *M, + SourceLocation ImportLoc, DeclContext *DC, + bool FromInclude = false) { + SourceLocation ExternCLoc; + + if (auto *LSD = dyn_cast(DC)) { + switch (LSD->getLanguage()) { + case LinkageSpecDecl::lang_c: + if (ExternCLoc.isInvalid()) + ExternCLoc = LSD->getBeginLoc(); + break; + case LinkageSpecDecl::lang_cxx: + break; + } + DC = LSD->getParent(); + } + + while (isa(DC) || isa(DC)) + DC = DC->getParent(); + + if (!isa(DC)) { + S.Diag(ImportLoc, (FromInclude && S.isModuleVisible(M)) + ? diag::ext_module_import_not_at_top_level_noop + : diag::err_module_import_not_at_top_level_fatal) + << M->getFullModuleName() << DC; + S.Diag(cast(DC)->getBeginLoc(), + diag::note_module_import_not_at_top_level) + << DC; + } else if (!M->IsExternC && ExternCLoc.isValid()) { + S.Diag(ImportLoc, diag::ext_module_import_in_extern_c) + << M->getFullModuleName(); + S.Diag(ExternCLoc, diag::note_extern_c_begins_here); + } +} + +Sema::DeclGroupPtrTy +Sema::ActOnGlobalModuleFragmentDecl(SourceLocation ModuleLoc) { + if (!ModuleScopes.empty() && + ModuleScopes.back().Module->Kind == Module::GlobalModuleFragment) { + // Under -std=c++2a -fmodules-ts, we can find an explicit 'module;' after + // already implicitly entering the global module fragment. That's OK. + assert(getLangOpts().CPlusPlusModules && getLangOpts().ModulesTS && + "unexpectedly encountered multiple global module fragment decls"); + ModuleScopes.back().BeginLoc = ModuleLoc; + return nullptr; + } + + // We start in the global module; all those declarations are implicitly + // module-private (though they do not have module linkage). + auto &Map = PP.getHeaderSearchInfo().getModuleMap(); + auto *GlobalModule = Map.createGlobalModuleForInterfaceUnit(ModuleLoc); + assert(GlobalModule && "module creation should not fail"); + + // Enter the scope of the global module. + ModuleScopes.push_back({}); + ModuleScopes.back().BeginLoc = ModuleLoc; + ModuleScopes.back().Module = GlobalModule; + VisibleModules.setVisible(GlobalModule, ModuleLoc); + + // All declarations created from now on are owned by the global module. + auto *TU = Context.getTranslationUnitDecl(); + TU->setModuleOwnershipKind(Decl::ModuleOwnershipKind::Visible); + TU->setLocalOwningModule(GlobalModule); + + // FIXME: Consider creating an explicit representation of this declaration. + return nullptr; +} + +Sema::DeclGroupPtrTy +Sema::ActOnModuleDecl(SourceLocation StartLoc, SourceLocation ModuleLoc, + ModuleDeclKind MDK, ModuleIdPath Path, bool IsFirstDecl) { + assert((getLangOpts().ModulesTS || getLangOpts().CPlusPlusModules) && + "should only have module decl in Modules TS or C++20"); + + // A module implementation unit requires that we are not compiling a module + // of any kind. A module interface unit requires that we are not compiling a + // module map. + switch (getLangOpts().getCompilingModule()) { + case LangOptions::CMK_None: + // It's OK to compile a module interface as a normal translation unit. + break; + + case LangOptions::CMK_ModuleInterface: + if (MDK != ModuleDeclKind::Implementation) + break; + + // We were asked to compile a module interface unit but this is a module + // implementation unit. That indicates the 'export' is missing. + Diag(ModuleLoc, diag::err_module_interface_implementation_mismatch) + << FixItHint::CreateInsertion(ModuleLoc, "export "); + MDK = ModuleDeclKind::Interface; + break; + + case LangOptions::CMK_ModuleMap: + Diag(ModuleLoc, diag::err_module_decl_in_module_map_module); + return nullptr; + + case LangOptions::CMK_HeaderModule: + Diag(ModuleLoc, diag::err_module_decl_in_header_module); + return nullptr; + } + + assert(ModuleScopes.size() <= 1 && "expected to be at global module scope"); + + // FIXME: Most of this work should be done by the preprocessor rather than + // here, in order to support macro import. + + // Only one module-declaration is permitted per source file. + if (!ModuleScopes.empty() && + ModuleScopes.back().Module->Kind == Module::ModuleInterfaceUnit) { + Diag(ModuleLoc, diag::err_module_redeclaration); + Diag(VisibleModules.getImportLoc(ModuleScopes.back().Module), + diag::note_prev_module_declaration); + return nullptr; + } + + // Find the global module fragment we're adopting into this module, if any. + Module *GlobalModuleFragment = nullptr; + if (!ModuleScopes.empty() && + ModuleScopes.back().Module->Kind == Module::GlobalModuleFragment) + GlobalModuleFragment = ModuleScopes.back().Module; + + // In C++20, the module-declaration must be the first declaration if there + // is no global module fragment. + if (getLangOpts().CPlusPlusModules && !IsFirstDecl && !GlobalModuleFragment) { + Diag(ModuleLoc, diag::err_module_decl_not_at_start); + SourceLocation BeginLoc = + ModuleScopes.empty() + ? SourceMgr.getLocForStartOfFile(SourceMgr.getMainFileID()) + : ModuleScopes.back().BeginLoc; + if (BeginLoc.isValid()) { + Diag(BeginLoc, diag::note_global_module_introducer_missing) + << FixItHint::CreateInsertion(BeginLoc, "module;\n"); + } + } + + // Flatten the dots in a module name. Unlike Clang's hierarchical module map + // modules, the dots here are just another character that can appear in a + // module name. + std::string ModuleName; + for (auto &Piece : Path) { + if (!ModuleName.empty()) + ModuleName += "."; + ModuleName += Piece.first->getName(); + } + + // If a module name was explicitly specified on the command line, it must be + // correct. + if (!getLangOpts().CurrentModule.empty() && + getLangOpts().CurrentModule != ModuleName) { + Diag(Path.front().second, diag::err_current_module_name_mismatch) + << SourceRange(Path.front().second, Path.back().second) + << getLangOpts().CurrentModule; + return nullptr; + } + const_cast(getLangOpts()).CurrentModule = ModuleName; + + auto &Map = PP.getHeaderSearchInfo().getModuleMap(); + Module *Mod; + + switch (MDK) { + case ModuleDeclKind::Interface: { + // We can't have parsed or imported a definition of this module or parsed a + // module map defining it already. + if (auto *M = Map.findModule(ModuleName)) { + Diag(Path[0].second, diag::err_module_redefinition) << ModuleName; + if (M->DefinitionLoc.isValid()) + Diag(M->DefinitionLoc, diag::note_prev_module_definition); + else if (const auto *FE = M->getASTFile()) + Diag(M->DefinitionLoc, diag::note_prev_module_definition_from_ast_file) + << FE->getName(); + Mod = M; + break; + } + + // Create a Module for the module that we're defining. + Mod = Map.createModuleForInterfaceUnit(ModuleLoc, ModuleName, + GlobalModuleFragment); + assert(Mod && "module creation should not fail"); + break; + } + + case ModuleDeclKind::Implementation: + std::pair ModuleNameLoc( + PP.getIdentifierInfo(ModuleName), Path[0].second); + Mod = getModuleLoader().loadModule(ModuleLoc, {ModuleNameLoc}, + Module::AllVisible, + /*IsIncludeDirective=*/false); + if (!Mod) { + Diag(ModuleLoc, diag::err_module_not_defined) << ModuleName; + // Create an empty module interface unit for error recovery. + Mod = Map.createModuleForInterfaceUnit(ModuleLoc, ModuleName, + GlobalModuleFragment); + } + break; + } + + if (!GlobalModuleFragment) { + ModuleScopes.push_back({}); + if (getLangOpts().ModulesLocalVisibility) + ModuleScopes.back().OuterVisibleModules = std::move(VisibleModules); + } + + // Switch from the global module fragment (if any) to the named module. + ModuleScopes.back().BeginLoc = StartLoc; + ModuleScopes.back().Module = Mod; + ModuleScopes.back().ModuleInterface = MDK != ModuleDeclKind::Implementation; + VisibleModules.setVisible(Mod, ModuleLoc); + + // From now on, we have an owning module for all declarations we see. + // However, those declarations are module-private unless explicitly + // exported. + auto *TU = Context.getTranslationUnitDecl(); + TU->setModuleOwnershipKind(Decl::ModuleOwnershipKind::ModulePrivate); + TU->setLocalOwningModule(Mod); + + // FIXME: Create a ModuleDecl. + return nullptr; +} + +DeclResult Sema::ActOnModuleImport(SourceLocation StartLoc, + SourceLocation ExportLoc, + SourceLocation ImportLoc, + ModuleIdPath Path) { + // Flatten the module path for a Modules TS module name. + std::pair ModuleNameLoc; + if (getLangOpts().ModulesTS) { + std::string ModuleName; + for (auto &Piece : Path) { + if (!ModuleName.empty()) + ModuleName += "."; + ModuleName += Piece.first->getName(); + } + ModuleNameLoc = {PP.getIdentifierInfo(ModuleName), Path[0].second}; + Path = ModuleIdPath(ModuleNameLoc); + } + + Module *Mod = + getModuleLoader().loadModule(ImportLoc, Path, Module::AllVisible, + /*IsIncludeDirective=*/false); + if (!Mod) + return true; + + return ActOnModuleImport(StartLoc, ExportLoc, ImportLoc, Mod, Path); +} + +DeclResult Sema::ActOnModuleImport(SourceLocation StartLoc, + SourceLocation ExportLoc, + SourceLocation ImportLoc, + Module *Mod, ModuleIdPath Path) { + VisibleModules.setVisible(Mod, ImportLoc); + + checkModuleImportContext(*this, Mod, ImportLoc, CurContext); + + // FIXME: we should support importing a submodule within a different submodule + // of the same top-level module. Until we do, make it an error rather than + // silently ignoring the import. + // Import-from-implementation is valid in the Modules TS. FIXME: Should we + // warn on a redundant import of the current module? + // FIXME: Import of a module from an implementation partition of the same + // module is permitted. + if (Mod->getTopLevelModuleName() == getLangOpts().CurrentModule && + (getLangOpts().isCompilingModule() || !getLangOpts().ModulesTS)) { + Diag(ImportLoc, getLangOpts().isCompilingModule() + ? diag::err_module_self_import + : diag::err_module_import_in_implementation) + << Mod->getFullModuleName() << getLangOpts().CurrentModule; + } + + SmallVector IdentifierLocs; + Module *ModCheck = Mod; + for (unsigned I = 0, N = Path.size(); I != N; ++I) { + // If we've run out of module parents, just drop the remaining identifiers. + // We need the length to be consistent. + if (!ModCheck) + break; + ModCheck = ModCheck->Parent; + + IdentifierLocs.push_back(Path[I].second); + } + + // If this was a header import, pad out with dummy locations. + // FIXME: Pass in and use the location of the header-name token in this case. + if (Path.empty()) { + for (; ModCheck; ModCheck = ModCheck->Parent) { + IdentifierLocs.push_back(SourceLocation()); + } + } + + ImportDecl *Import = ImportDecl::Create(Context, CurContext, StartLoc, + Mod, IdentifierLocs); + CurContext->addDecl(Import); + + // Sequence initialization of the imported module before that of the current + // module, if any. + if (!ModuleScopes.empty()) + Context.addModuleInitializer(ModuleScopes.back().Module, Import); + + // Re-export the module if needed. + if (!ModuleScopes.empty() && ModuleScopes.back().ModuleInterface) { + if (ExportLoc.isValid() || Import->isExported()) + getCurrentModule()->Exports.emplace_back(Mod, false); + } else if (ExportLoc.isValid()) { + Diag(ExportLoc, diag::err_export_not_in_module_interface); + } + + return Import; +} + +void Sema::ActOnModuleInclude(SourceLocation DirectiveLoc, Module *Mod) { + checkModuleImportContext(*this, Mod, DirectiveLoc, CurContext, true); + BuildModuleInclude(DirectiveLoc, Mod); +} + +void Sema::BuildModuleInclude(SourceLocation DirectiveLoc, Module *Mod) { + // Determine whether we're in the #include buffer for a module. The #includes + // in that buffer do not qualify as module imports; they're just an + // implementation detail of us building the module. + // + // FIXME: Should we even get ActOnModuleInclude calls for those? + bool IsInModuleIncludes = + TUKind == TU_Module && + getSourceManager().isWrittenInMainFile(DirectiveLoc); + + bool ShouldAddImport = !IsInModuleIncludes; + + // If this module import was due to an inclusion directive, create an + // implicit import declaration to capture it in the AST. + if (ShouldAddImport) { + TranslationUnitDecl *TU = getASTContext().getTranslationUnitDecl(); + ImportDecl *ImportD = ImportDecl::CreateImplicit(getASTContext(), TU, + DirectiveLoc, Mod, + DirectiveLoc); + if (!ModuleScopes.empty()) + Context.addModuleInitializer(ModuleScopes.back().Module, ImportD); + TU->addDecl(ImportD); + Consumer.HandleImplicitImportDecl(ImportD); + } + + getModuleLoader().makeModuleVisible(Mod, Module::AllVisible, DirectiveLoc); + VisibleModules.setVisible(Mod, DirectiveLoc); +} + +void Sema::ActOnModuleBegin(SourceLocation DirectiveLoc, Module *Mod) { + checkModuleImportContext(*this, Mod, DirectiveLoc, CurContext, true); + + ModuleScopes.push_back({}); + ModuleScopes.back().Module = Mod; + if (getLangOpts().ModulesLocalVisibility) + ModuleScopes.back().OuterVisibleModules = std::move(VisibleModules); + + VisibleModules.setVisible(Mod, DirectiveLoc); + + // The enclosing context is now part of this module. + // FIXME: Consider creating a child DeclContext to hold the entities + // lexically within the module. + if (getLangOpts().trackLocalOwningModule()) { + for (auto *DC = CurContext; DC; DC = DC->getLexicalParent()) { + cast(DC)->setModuleOwnershipKind( + getLangOpts().ModulesLocalVisibility + ? Decl::ModuleOwnershipKind::VisibleWhenImported + : Decl::ModuleOwnershipKind::Visible); + cast(DC)->setLocalOwningModule(Mod); + } + } +} + +void Sema::ActOnModuleEnd(SourceLocation EomLoc, Module *Mod) { + if (getLangOpts().ModulesLocalVisibility) { + VisibleModules = std::move(ModuleScopes.back().OuterVisibleModules); + // Leaving a module hides namespace names, so our visible namespace cache + // is now out of date. + VisibleNamespaceCache.clear(); + } + + assert(!ModuleScopes.empty() && ModuleScopes.back().Module == Mod && + "left the wrong module scope"); + ModuleScopes.pop_back(); + + // We got to the end of processing a local module. Create an + // ImportDecl as we would for an imported module. + FileID File = getSourceManager().getFileID(EomLoc); + SourceLocation DirectiveLoc; + if (EomLoc == getSourceManager().getLocForEndOfFile(File)) { + // We reached the end of a #included module header. Use the #include loc. + assert(File != getSourceManager().getMainFileID() && + "end of submodule in main source file"); + DirectiveLoc = getSourceManager().getIncludeLoc(File); + } else { + // We reached an EOM pragma. Use the pragma location. + DirectiveLoc = EomLoc; + } + BuildModuleInclude(DirectiveLoc, Mod); + + // Any further declarations are in whatever module we returned to. + if (getLangOpts().trackLocalOwningModule()) { + // The parser guarantees that this is the same context that we entered + // the module within. + for (auto *DC = CurContext; DC; DC = DC->getLexicalParent()) { + cast(DC)->setLocalOwningModule(getCurrentModule()); + if (!getCurrentModule()) + cast(DC)->setModuleOwnershipKind( + Decl::ModuleOwnershipKind::Unowned); + } + } +} + +void Sema::createImplicitModuleImportForErrorRecovery(SourceLocation Loc, + Module *Mod) { + // Bail if we're not allowed to implicitly import a module here. + if (isSFINAEContext() || !getLangOpts().ModulesErrorRecovery || + VisibleModules.isVisible(Mod)) + return; + + // Create the implicit import declaration. + TranslationUnitDecl *TU = getASTContext().getTranslationUnitDecl(); + ImportDecl *ImportD = ImportDecl::CreateImplicit(getASTContext(), TU, + Loc, Mod, Loc); + TU->addDecl(ImportD); + Consumer.HandleImplicitImportDecl(ImportD); + + // Make the module visible. + getModuleLoader().makeModuleVisible(Mod, Module::AllVisible, Loc); + VisibleModules.setVisible(Mod, Loc); +} + +/// We have parsed the start of an export declaration, including the '{' +/// (if present). +Decl *Sema::ActOnStartExportDecl(Scope *S, SourceLocation ExportLoc, + SourceLocation LBraceLoc) { + ExportDecl *D = ExportDecl::Create(Context, CurContext, ExportLoc); + + // C++ Modules TS draft: + // An export-declaration shall appear in the purview of a module other than + // the global module. + if (ModuleScopes.empty() || !ModuleScopes.back().ModuleInterface) + Diag(ExportLoc, diag::err_export_not_in_module_interface); + + // An export-declaration [...] shall not contain more than one + // export keyword. + // + // The intent here is that an export-declaration cannot appear within another + // export-declaration. + if (D->isExported()) + Diag(ExportLoc, diag::err_export_within_export); + + CurContext->addDecl(D); + PushDeclContext(S, D); + D->setModuleOwnershipKind(Decl::ModuleOwnershipKind::VisibleWhenImported); + return D; +} + +/// Complete the definition of an export declaration. +Decl *Sema::ActOnFinishExportDecl(Scope *S, Decl *D, SourceLocation RBraceLoc) { + auto *ED = cast(D); + if (RBraceLoc.isValid()) + ED->setRBraceLoc(RBraceLoc); + + // FIXME: Diagnose export of internal-linkage declaration (including + // anonymous namespace). + + PopDeclContext(); + return D; +}