Revert "[C++20][Modules] Build module static initializers per P1874R1."

This reverts commit ac50710.

reverting while we figuere out why one of the green dragon lldb test fails.

Author: iains

clang/include/clang/AST/ASTContext.h

@@ -472,9 +472,6 @@ class ASTContext : public RefCountedBase<ASTContext> {
   };
   llvm::DenseMap<Module*, PerModuleInitializers*> ModuleInitializers;
 
-  /// For module code-gen cases, this is the top-level module we are building.
-  Module *TopLevelModule = nullptr;
-
   static constexpr unsigned ConstantArrayTypesLog2InitSize = 8;
   static constexpr unsigned GeneralTypesLog2InitSize = 9;
   static constexpr unsigned FunctionProtoTypesLog2InitSize = 12;
@@ -1078,12 +1075,6 @@ class ASTContext : public RefCountedBase<ASTContext> {
   /// Get the initializations to perform when importing a module, if any.
   ArrayRef<Decl*> getModuleInitializers(Module *M);
 
-  /// Set the (C++20) module we are building.
-  void setModuleForCodeGen(Module *M) { TopLevelModule = M; }
-
-  /// Get module under construction, nullptr if this is not a C++20 module.
-  Module *getModuleForCodeGen() const { return TopLevelModule; }
-
   TranslationUnitDecl *getTranslationUnitDecl() const {
     return TUDecl->getMostRecentDecl();
   }

clang/include/clang/Basic/Module.h

@@ -665,18 +665,6 @@ class Module {
   Module *findSubmodule(StringRef Name) const;
   Module *findOrInferSubmodule(StringRef Name);
 
-  /// Get the Global Module Fragment (sub-module) for this module, it there is
-  /// one.
-  ///
-  /// \returns The GMF sub-module if found, or NULL otherwise.
-  Module *getGlobalModuleFragment() { return findSubmodule("<global>"); }
-
-  /// Get the Private Module Fragment (sub-module) for this module, it there is
-  /// one.
-  ///
-  /// \returns The PMF sub-module if found, or NULL otherwise.
-  Module *getPrivateModuleFragment() { return findSubmodule("<private>"); }
-
   /// Determine whether the specified module would be visible to
   /// a lookup at the end of this module.
   ///

clang/include/clang/Sema/Sema.h

@@ -2281,11 +2281,6 @@ class Sema final {
     return ModuleScopes.empty() ? nullptr : ModuleScopes.back().Module;
   }
 
-  /// Is the module scope we are an interface?
-  bool currentModuleIsInterface() const {
-    return ModuleScopes.empty() ? false : ModuleScopes.back().ModuleInterface;
-  }
-
   /// Get the module owning an entity.
   Module *getOwningModule(const Decl *Entity) {
     return Entity->getOwningModule();

clang/lib/CodeGen/CGDeclCXX.cpp

@@ -618,127 +618,6 @@ void CodeGenModule::EmitCXXThreadLocalInitFunc() {
   CXXThreadLocals.clear();
 }
 
-/* Build the initializer for a C++20 module:
-   This is arranged to be run only once regardless of how many times the module
-   might be included transitively.  This arranged by using a control variable.
-
-   First we call any initializers for imported modules.
-   We then call initializers for the Global Module Fragment (if present)
-   We then call initializers for the current module.
-   We then call initializers for the Private Module Fragment (if present)
-*/
-
-void CodeGenModule::EmitCXXModuleInitFunc(Module *Primary) {
-  while (!CXXGlobalInits.empty() && !CXXGlobalInits.back())
-    CXXGlobalInits.pop_back();
-
-  // We create the function, even if it is empty, since an importer of this
-  // module will refer to it unconditionally (for the current implementation
-  // there is no way for the importer to know that an importee does not need
-  // an initializer to be run).
-
-  // Module initializers for imported modules are emitted first.
-  // Collect the modules that we import
-  SmallVector<Module *> AllImports;
-  // Ones that we export
-  for (auto I : Primary->Exports)
-    AllImports.push_back(I.getPointer());
-  // Ones that we only import.
-  for (Module *M : Primary->Imports)
-    AllImports.push_back(M);
-
-  SmallVector<llvm::Function *, 8> ModuleInits;
-  for (Module *M : AllImports) {
-    llvm::FunctionType *FTy = llvm::FunctionType::get(VoidTy, false);
-    SmallString<256> FnName;
-    {
-      llvm::raw_svector_ostream Out(FnName);
-      cast<ItaniumMangleContext>(getCXXABI().getMangleContext())
-          .mangleModuleInitializer(M, Out);
-    }
-    assert(!GetGlobalValue(FnName.str()) &&
-           "We should only have one use of the initializer call");
-    llvm::Function *Fn = llvm::Function::Create(
-        FTy, llvm::Function::ExternalLinkage, FnName.str(), &getModule());
-    ModuleInits.push_back(Fn);
-  }
-  AllImports.clear();
-
-  // Add any initializers with specified priority; this uses the same  approach
-  // as EmitCXXGlobalInitFunc().
-  if (!PrioritizedCXXGlobalInits.empty()) {
-    SmallVector<llvm::Function *, 8> LocalCXXGlobalInits;
-    llvm::array_pod_sort(PrioritizedCXXGlobalInits.begin(),
-                         PrioritizedCXXGlobalInits.end());
-    for (SmallVectorImpl<GlobalInitData>::iterator
-             I = PrioritizedCXXGlobalInits.begin(),
-             E = PrioritizedCXXGlobalInits.end();
-         I != E;) {
-      SmallVectorImpl<GlobalInitData>::iterator PrioE =
-          std::upper_bound(I + 1, E, *I, GlobalInitPriorityCmp());
-
-      for (; I < PrioE; ++I)
-        ModuleInits.push_back(I->second);
-    }
-    PrioritizedCXXGlobalInits.clear();
-  }
-
-  // Now append the ones without specified priority.
-  for (auto F : CXXGlobalInits)
-    ModuleInits.push_back(F);
-  CXXGlobalInits.clear();
-
-  llvm::FunctionType *FTy = llvm::FunctionType::get(VoidTy, false);
-  const CGFunctionInfo &FI = getTypes().arrangeNullaryFunction();
-
-  // We now build the initializer for this module, which has a mangled name
-  // as per the Itanium ABI .  The action of the initializer is guarded so that
-  // each init is run just once (even though a module might be imported
-  // multiple times via nested use).
-  llvm::Function *Fn;
-  llvm::GlobalVariable *Guard = nullptr;
-  {
-    SmallString<256> InitFnName;
-    llvm::raw_svector_ostream Out(InitFnName);
-    cast<ItaniumMangleContext>(getCXXABI().getMangleContext())
-        .mangleModuleInitializer(Primary, Out);
-    Fn = CreateGlobalInitOrCleanUpFunction(
-        FTy, llvm::Twine(InitFnName), FI, SourceLocation(), false,
-        llvm::GlobalVariable::ExternalLinkage);
-
-    Guard = new llvm::GlobalVariable(getModule(), Int8Ty, /*isConstant=*/false,
-                                     llvm::GlobalVariable::InternalLinkage,
-                                     llvm::ConstantInt::get(Int8Ty, 0),
-                                     InitFnName.str() + "__in_chrg");
-  }
-  CharUnits GuardAlign = CharUnits::One();
-  Guard->setAlignment(GuardAlign.getAsAlign());
-
-  CodeGenFunction(*this).GenerateCXXGlobalInitFunc(
-      Fn, ModuleInits, ConstantAddress(Guard, Int8Ty, GuardAlign));
-  // We allow for the case that a module object is added to  a linked binary
-  // without a specific call to the the initializer.  This also ensure that
-  // implementation partition initializers are called when the partition
-  // is not imported as an interface.
-  AddGlobalCtor(Fn);
-
-  // See the comment in EmitCXXGlobalInitFunc about OpenCL global init
-  // functions.
-  if (getLangOpts().OpenCL) {
-    GenKernelArgMetadata(Fn);
-    Fn->setCallingConv(llvm::CallingConv::SPIR_KERNEL);
-  }
-
-  assert(!getLangOpts().CUDA || !getLangOpts().CUDAIsDevice ||
-         getLangOpts().GPUAllowDeviceInit);
-  if (getLangOpts().HIP && getLangOpts().CUDAIsDevice) {
-    Fn->setCallingConv(llvm::CallingConv::AMDGPU_KERNEL);
-    Fn->addFnAttr("device-init");
-  }
-
-  ModuleInits.clear();
-}
-
 static SmallString<128> getTransformedFileName(llvm::Module &M) {
   SmallString<128> FileName = llvm::sys::path::filename(M.getName());
 
@@ -771,26 +650,7 @@ CodeGenModule::EmitCXXGlobalInitFunc() {
   while (!CXXGlobalInits.empty() && !CXXGlobalInits.back())
     CXXGlobalInits.pop_back();
 
-  // When we import C++20 modules, we must run their initializers first.
-  SmallVector<llvm::Function *, 8> ModuleInits;
-  if (CXX20ModuleInits)
-    for (Module *M : ImportedModules) {
-      llvm::FunctionType *FTy = llvm::FunctionType::get(VoidTy, false);
-      SmallString<256> FnName;
-      {
-        llvm::raw_svector_ostream Out(FnName);
-        cast<ItaniumMangleContext>(getCXXABI().getMangleContext())
-            .mangleModuleInitializer(M, Out);
-      }
-      assert(!GetGlobalValue(FnName.str()) &&
-             "We should only have one use of the initializer call");
-      llvm::Function *Fn = llvm::Function::Create(
-          FTy, llvm::Function::ExternalLinkage, FnName.str(), &getModule());
-      ModuleInits.push_back(Fn);
-    }
-
-  if (ModuleInits.empty() && CXXGlobalInits.empty() &&
-      PrioritizedCXXGlobalInits.empty())
+  if (CXXGlobalInits.empty() && PrioritizedCXXGlobalInits.empty())
     return;
 
   llvm::FunctionType *FTy = llvm::FunctionType::get(VoidTy, false);
@@ -816,13 +676,6 @@ CodeGenModule::EmitCXXGlobalInitFunc() {
       llvm::Function *Fn = CreateGlobalInitOrCleanUpFunction(
           FTy, "_GLOBAL__I_" + getPrioritySuffix(Priority), FI);
 
-      // Prepend the module inits to the highest priority set.
-      if (!ModuleInits.empty()) {
-        for (auto F : ModuleInits)
-          LocalCXXGlobalInits.push_back(F);
-        ModuleInits.clear();
-      }
-
       for (; I < PrioE; ++I)
         LocalCXXGlobalInits.push_back(I->second);
 
@@ -832,33 +685,17 @@ CodeGenModule::EmitCXXGlobalInitFunc() {
     PrioritizedCXXGlobalInits.clear();
   }
 
-  if (getCXXABI().useSinitAndSterm() && ModuleInits.empty() &&
-      CXXGlobalInits.empty())
+  if (getCXXABI().useSinitAndSterm() && CXXGlobalInits.empty())
     return;
 
-  for (auto F : CXXGlobalInits)
-    ModuleInits.push_back(F);
-  CXXGlobalInits.clear();
-
   // Include the filename in the symbol name. Including "sub_" matches gcc
   // and makes sure these symbols appear lexicographically behind the symbols
   // with priority emitted above.
-  llvm::Function *Fn;
-  if (CXX20ModuleInits && getContext().getModuleForCodeGen()) {
-    SmallString<256> InitFnName;
-    llvm::raw_svector_ostream Out(InitFnName);
-    cast<ItaniumMangleContext>(getCXXABI().getMangleContext())
-        .mangleModuleInitializer(getContext().getModuleForCodeGen(), Out);
-    Fn = CreateGlobalInitOrCleanUpFunction(
-        FTy, llvm::Twine(InitFnName), FI, SourceLocation(), false,
-        llvm::GlobalVariable::ExternalLinkage);
-  } else
-    Fn = CreateGlobalInitOrCleanUpFunction(
-        FTy,
-        llvm::Twine("_GLOBAL__sub_I_", getTransformedFileName(getModule())),
-        FI);
-
-  CodeGenFunction(*this).GenerateCXXGlobalInitFunc(Fn, ModuleInits);
+  llvm::Function *Fn = CreateGlobalInitOrCleanUpFunction(
+      FTy, llvm::Twine("_GLOBAL__sub_I_", getTransformedFileName(getModule())),
+      FI);
+
+  CodeGenFunction(*this).GenerateCXXGlobalInitFunc(Fn, CXXGlobalInits);
   AddGlobalCtor(Fn);
 
   // In OpenCL global init functions must be converted to kernels in order to
@@ -881,7 +718,7 @@ CodeGenModule::EmitCXXGlobalInitFunc() {
     Fn->addFnAttr("device-init");
   }
 
-  ModuleInits.clear();
+  CXXGlobalInits.clear();
 }
 
 void CodeGenModule::EmitCXXGlobalCleanUpFunc() {

clang/lib/CodeGen/CodeGenModule.cpp

@@ -136,13 +136,6 @@ CodeGenModule::CodeGenModule(ASTContext &C, const HeaderSearchOptions &HSO,
   GlobalsInt8PtrTy = Int8Ty->getPointerTo(DL.getDefaultGlobalsAddressSpace());
   ASTAllocaAddressSpace = getTargetCodeGenInfo().getASTAllocaAddressSpace();
 
-  // Build C++20 Module initializers.
-  // TODO: Add Microsoft here once we know the mangling required for the
-  // initializers.
-  CXX20ModuleInits =
-      LangOpts.CPlusPlusModules && getCXXABI().getMangleContext().getKind() ==
-                                       ItaniumMangleContext::MK_Itanium;
-
   RuntimeCC = getTargetCodeGenInfo().getABIInfo().getRuntimeCC();
 
   if (LangOpts.ObjC)
@@ -516,18 +509,12 @@ static void setVisibilityFromDLLStorageClass(const clang::LangOptions &LO,
 }
 
 void CodeGenModule::Release() {
-  Module *Primary = getContext().getModuleForCodeGen();
-  if (CXX20ModuleInits && Primary)
-    EmitModuleInitializers(Primary);
   EmitDeferred();
   EmitVTablesOpportunistically();
   applyGlobalValReplacements();
   applyReplacements();
   emitMultiVersionFunctions();
-  if (CXX20ModuleInits && Primary && Primary->isInterfaceOrPartition())
-    EmitCXXModuleInitFunc(Primary);
-  else
-    EmitCXXGlobalInitFunc();
+  EmitCXXGlobalInitFunc();
   EmitCXXGlobalCleanUpFunc();
   registerGlobalDtorsWithAtExit();
   EmitCXXThreadLocalInitFunc();
@@ -2504,31 +2491,6 @@ static void addLinkOptionsPostorder(CodeGenModule &CGM, Module *Mod,
   }
 }
 
-void CodeGenModule::EmitModuleInitializers(clang::Module *Primary) {
-  // Emit the initializers in the order that sub-modules appear in the
-  // source, first Global Module Fragments, if present.
-  if (auto GMF = Primary->getGlobalModuleFragment()) {
-    for (Decl *D : getContext().getModuleInitializers(GMF)) {
-      assert(D->getKind() == Decl::Var && "GMF initializer decl is not a var?");
-      EmitTopLevelDecl(D);
-    }
-  }
-  // Second any associated with the module, itself.
-  for (Decl *D : getContext().getModuleInitializers(Primary)) {
-    // Skip import decls, the inits for those are called explicitly.
-    if (D->getKind() == Decl::Import)
-      continue;
-    EmitTopLevelDecl(D);
-  }
-  // Third any associated with the Privat eMOdule Fragment, if present.
-  if (auto PMF = Primary->getPrivateModuleFragment()) {
-    for (Decl *D : getContext().getModuleInitializers(PMF)) {
-      assert(D->getKind() == Decl::Var && "PMF initializer decl is not a var?");
-      EmitTopLevelDecl(D);
-    }
-  }
-}
-
 void CodeGenModule::EmitModuleLinkOptions() {
   // Collect the set of all of the modules we want to visit to emit link
   // options, which is essentially the imported modules and all of their
@@ -2934,19 +2896,12 @@ bool CodeGenModule::MayBeEmittedEagerly(const ValueDecl *Global) {
       // explicitly instantiated, so they should not be emitted eagerly.
       return false;
   }
-  if (const auto *VD = dyn_cast<VarDecl>(Global)) {
+  if (const auto *VD = dyn_cast<VarDecl>(Global))
     if (Context.getInlineVariableDefinitionKind(VD) ==
         ASTContext::InlineVariableDefinitionKind::WeakUnknown)
       // A definition of an inline constexpr static data member may change
       // linkage later if it's redeclared outside the class.
       return false;
-    if (CXX20ModuleInits && VD->getOwningModule()) {
-      // For CXX20, module-owned initializers need to be deferred, since it is
-      // not known at this point if they will be run for the current module or
-      // as part of the initializer for an imported one.
-      return false;
-    }
-  }
   // If OpenMP is enabled and threadprivates must be generated like TLS, delay
   // codegen for global variables, because they may be marked as threadprivate.
   if (LangOpts.OpenMP && LangOpts.OpenMPUseTLS &&
@@ -6243,12 +6198,6 @@ void CodeGenModule::EmitTopLevelDecl(Decl *D) {
         DI->EmitImportDecl(*Import);
     }
 
-    // For CXX20 we are done - we will call the module initializer for the
-    // imported module, and that will likewise call those for any imports it
-    // has.
-    if (CXX20ModuleInits)
-      break;
-
     // Find all of the submodules and emit the module initializers.
     llvm::SmallPtrSet<clang::Module *, 16> Visited;
     SmallVector<clang::Module *, 16> Stack;