[NFC] [C++20] [Modules] Use new class CXX20ModulesGenerator to genera… (#90570)

…te module file for C++20 modules instead of PCHGenerator Previously we're re-using PCHGenerator to generate the module file for C++20 modules. But this is slighty more or less odd. This patch tries to use a new class 'CXX20ModulesGenerator' to generate the module file for C++20 modules.

Author: ChuanqiXu9

clang/include/clang/Serialization/ASTWriter.h

@@ -890,6 +890,8 @@ class ASTWriter : public ASTDeserializationListener,
 /// AST and semantic-analysis consumer that generates a
 /// precompiled header from the parsed source code.
 class PCHGenerator : public SemaConsumer {
+ void anchor() override;
+
  Preprocessor &PP;
  std::string OutputFile;
  std::string isysroot;
@@ -933,17 +935,34 @@ class PCHGenerator : public SemaConsumer {
  bool hasEmittedPCH() const { return Buffer->IsComplete; }
 };
 
-class ReducedBMIGenerator : public PCHGenerator {
+class CXX20ModulesGenerator : public PCHGenerator {
+ void anchor() override;
+
 protected:
  virtual Module *getEmittingModule(ASTContext &Ctx) override;
 
+ CXX20ModulesGenerator(Preprocessor &PP, InMemoryModuleCache &ModuleCache,
+ StringRef OutputFile, bool GeneratingReducedBMI);
+
 public:
- ReducedBMIGenerator(Preprocessor &PP, InMemoryModuleCache &ModuleCache,
- StringRef OutputFile);
+ CXX20ModulesGenerator(Preprocessor &PP, InMemoryModuleCache &ModuleCache,
+ StringRef OutputFile)
+ : CXX20ModulesGenerator(PP, ModuleCache, OutputFile,
+ /*GeneratingReducedBMI=*/false) {}
 
  void HandleTranslationUnit(ASTContext &Ctx) override;
 };
 
+class ReducedBMIGenerator : public CXX20ModulesGenerator {
+ void anchor() override;
+
+public:
+ ReducedBMIGenerator(Preprocessor &PP, InMemoryModuleCache &ModuleCache,
+ StringRef OutputFile)
+ : CXX20ModulesGenerator(PP, ModuleCache, OutputFile,
+ /*GeneratingReducedBMI=*/true) {}
+};
+
 /// If we can elide the definition of \param D in reduced BMI.
 ///
 /// Generally, we can elide the definition of a declaration if it won't affect

clang/lib/Frontend/FrontendActions.cpp

@@ -272,13 +272,10 @@ bool GenerateModuleInterfaceAction::BeginSourceFileAction(
 std::unique_ptr<ASTConsumer>
 GenerateModuleInterfaceAction::CreateASTConsumer(CompilerInstance &CI,
  StringRef InFile) {
- CI.getHeaderSearchOpts().ModulesSkipDiagnosticOptions = true;
- CI.getHeaderSearchOpts().ModulesSkipHeaderSearchPaths = true;
-
- std::vector<std::unique_ptr<ASTConsumer>> Consumers =
- CreateMultiplexConsumer(CI, InFile);
- if (Consumers.empty())
- return nullptr;
+ std::vector<std::unique_ptr<ASTConsumer>> Consumers;
+ Consumers.push_back(std::make_unique<CXX20ModulesGenerator>(
+ CI.getPreprocessor(), CI.getModuleCache(),
+ CI.getFrontendOpts().OutputFile));
 
  if (CI.getFrontendOpts().GenReducedBMI &&
  !CI.getFrontendOpts().ModuleOutputPath.empty()) {

clang/lib/Serialization/GeneratePCH.cpp

@@ -88,31 +88,30 @@ ASTDeserializationListener *PCHGenerator::GetASTDeserializationListener() {
  return &Writer;
 }
 
-ReducedBMIGenerator::ReducedBMIGenerator(Preprocessor &PP,
- InMemoryModuleCache &ModuleCache,
- StringRef OutputFile)
+void PCHGenerator::anchor() {}
+
+CXX20ModulesGenerator::CXX20ModulesGenerator(Preprocessor &PP,
+ InMemoryModuleCache &ModuleCache,
+ StringRef OutputFile,
+ bool GeneratingReducedBMI)
  : PCHGenerator(
  PP, ModuleCache, OutputFile, llvm::StringRef(),
  std::make_shared<PCHBuffer>(),
  /*Extensions=*/ArrayRef<std::shared_ptr<ModuleFileExtension>>(),
  /*AllowASTWithErrors*/ false, /*IncludeTimestamps=*/false,
  /*BuildingImplicitModule=*/false, /*ShouldCacheASTInMemory=*/false,
- /*GeneratingReducedBMI=*/true) {}
+ GeneratingReducedBMI) {}
 
-Module *ReducedBMIGenerator::getEmittingModule(ASTContext &Ctx) {
+Module *CXX20ModulesGenerator::getEmittingModule(ASTContext &Ctx) {
  Module *M = Ctx.getCurrentNamedModule();
  assert(M && M->isNamedModuleUnit() &&
- "ReducedBMIGenerator should only be used with C++20 Named modules.");
+ "CXX20ModulesGenerator should only be used with C++20 Named modules.");
  return M;
 }
 
-void ReducedBMIGenerator::HandleTranslationUnit(ASTContext &Ctx) {
- // We need to do this to make sure the size of reduced BMI not to be larger
- // than full BMI.
- //
+void CXX20ModulesGenerator::HandleTranslationUnit(ASTContext &Ctx) {
  // FIMXE: We'd better to wrap such options to a new class ASTWriterOptions
  // since this is not about searching header really.
- // FIXME2: We'd better to move the class writing full BMI with reduced BMI.
  HeaderSearchOptions &HSOpts =
  getPreprocessor().getHeaderSearchInfo().getHeaderSearchOpts();
  HSOpts.ModulesSkipDiagnosticOptions = true;
@@ -134,3 +133,7 @@ void ReducedBMIGenerator::HandleTranslationUnit(ASTContext &Ctx) {
  *OS << getBufferPtr()->Data;
  OS->flush();
 }
+
+void CXX20ModulesGenerator::anchor() {}
+
+void ReducedBMIGenerator::anchor() {}

clang/test/Modules/pr67893.cppm

@@ -5,7 +5,7 @@
 // RUN: %clang_cc1 -triple %itanium_abi_triple -std=c++20 %t/a.cppm \
 // RUN: -emit-module-interface -o %t/a.pcm
 // RUN: %clang_cc1 -triple %itanium_abi_triple -std=c++20 %t/m.cppm \
-// RUN: -emit-module-interface -fprebuilt-module-path=%t
+// RUN: -emit-module-interface -fprebuilt-module-path=%t -o %t/m.pcm
 // RUN: %clang_cc1 -triple %itanium_abi_triple -std=c++20 %t/m.pcm \
 // RUN: -fprebuilt-module-path=%t -S -emit-llvm -o - | FileCheck %t/m.cppm
 

clang/test/Modules/search-partitions.cpp

@@ -11,7 +11,7 @@
 // RUN: %clang_cc1 -std=c++20 -emit-module-interface %t/partition3.cpp \
 // RUN: -o %t/A-Part3.pcm
 
-// RUN: %clang_cc1 -std=c++20 -emit-module-interface %t/moduleA.cpp \
+// RUN: %clang_cc1 -std=c++20 %t/moduleA.cpp -fsyntax-only -verify \
 // RUN: -fprebuilt-module-path=%t
 
 // Test again with reduced BMI
@@ -28,9 +28,7 @@
 // RUN: %clang_cc1 -std=c++20 -emit-reduced-module-interface %t/partition3.cpp \
 // RUN: -o %t/A-Part3.pcm
 
-// RUN: %clang_cc1 -std=c++20 -fsyntax-only %t/moduleA.cpp -fprebuilt-module-path=%t 
-
-// expected-no-diagnostics
+// RUN: %clang_cc1 -std=c++20 -fsyntax-only -verify %t/moduleA.cpp -fprebuilt-module-path=%t 
 
 //--- partition1.cpp
 export module A:Part1;
@@ -50,7 +48,7 @@ export module A:Part3;
 int part3();
 
 //--- moduleA.cpp
-
+// expected-no-diagnostics
 export module A;
 
 import :Part1;