8 files changed, 17 insertions, 27 deletions
diff --git a/clang/include/clang/AST/ASTConsumer.h b/clang/include/clang/AST/ASTConsumer.h
index 736a10bec9b..b2730e46222 100644
--- a/clang/include/clang/AST/ASTConsumer.h
+++ b/clang/include/clang/AST/ASTConsumer.h
@@ -129,11 +129,7 @@ public:
   /// required.
   ///
   /// \param RD The class whose vtable was used.
-  ///
-  /// \param DefinitionRequired Whether a definition of this vtable is
-  /// required in this translation unit; otherwise, it is only needed if
-  /// it was actually used.
-  virtual void HandleVTable(CXXRecordDecl *RD, bool DefinitionRequired) {}
+  virtual void HandleVTable(CXXRecordDecl *RD) {}
 
   /// \brief If the consumer is interested in entities getting modified after
   /// their initial creation, it should return a pointer to
diff --git a/clang/include/clang/Frontend/MultiplexConsumer.h b/clang/include/clang/Frontend/MultiplexConsumer.h
index c9122dacb8f..2553275dac1 100644
--- a/clang/include/clang/Frontend/MultiplexConsumer.h
+++ b/clang/include/clang/Frontend/MultiplexConsumer.h
@@ -49,7 +49,7 @@ public:
                             llvm::StringRef Value) override;
   void HandleDependentLibrary(llvm::StringRef Lib) override;
   void CompleteTentativeDefinition(VarDecl *D) override;
-  void HandleVTable(CXXRecordDecl *RD, bool DefinitionRequired) override;
+  void HandleVTable(CXXRecordDecl *RD) override;
   ASTMutationListener *GetASTMutationListener() override;
   ASTDeserializationListener *GetASTDeserializationListener() override;
   void PrintStats() override;
diff --git a/clang/lib/CodeGen/CGVTables.cpp b/clang/lib/CodeGen/CGVTables.cpp
index acb2a56fab3..5416d441672 100644
--- a/clang/lib/CodeGen/CGVTables.cpp
+++ b/clang/lib/CodeGen/CGVTables.cpp
@@ -747,19 +747,13 @@ CodeGenModule::getVTableLinkage(const CXXRecordDecl *RD) {
   llvm_unreachable("Invalid TemplateSpecializationKind!");
 }
 
-/// This is a callback from Sema to tell us that it believes that a
-/// particular v-table is required to be emitted in this translation
-/// unit.
+/// This is a callback from Sema to tell us that that a particular v-table is
+/// required to be emitted in this translation unit.
 ///
-/// The reason we don't simply trust this callback is because Sema
-/// will happily report that something is used even when it's used
-/// only in code that we don't actually have to emit.
-///
-/// \param isRequired - if true, the v-table is mandatory, e.g.
-///   because the translation unit defines the key function
-void CodeGenModule::EmitVTable(CXXRecordDecl *theClass, bool isRequired) {
-  if (!isRequired) return;
-
+/// This is only called for vtables that _must_ be emitted (mainly due to key
+/// functions).  For weak vtables, CodeGen tracks when they are needed and
+/// emits them as-needed.
+void CodeGenModule::EmitVTable(CXXRecordDecl *theClass) {
   VTables.GenerateClassData(theClass);
 }
 
diff --git a/clang/lib/CodeGen/CodeGenAction.cpp b/clang/lib/CodeGen/CodeGenAction.cpp
index a6f6fdef335..c459a210cee 100644
--- a/clang/lib/CodeGen/CodeGenAction.cpp
+++ b/clang/lib/CodeGen/CodeGenAction.cpp
@@ -196,8 +196,8 @@ namespace clang {
       Gen->CompleteTentativeDefinition(D);
     }
 
-    void HandleVTable(CXXRecordDecl *RD, bool DefinitionRequired) override {
-      Gen->HandleVTable(RD, DefinitionRequired);
+    void HandleVTable(CXXRecordDecl *RD) override {
+      Gen->HandleVTable(RD);
     }
 
     void HandleLinkerOptionPragma(llvm::StringRef Opts) override {
diff --git a/clang/lib/CodeGen/CodeGenModule.h b/clang/lib/CodeGen/CodeGenModule.h
index 54f3a82feb2..ddcb414508a 100644
--- a/clang/lib/CodeGen/CodeGenModule.h
+++ b/clang/lib/CodeGen/CodeGenModule.h
@@ -993,7 +993,7 @@ public:
 
   void EmitTentativeDefinition(const VarDecl *D);
 
-  void EmitVTable(CXXRecordDecl *Class, bool DefinitionRequired);
+  void EmitVTable(CXXRecordDecl *Class);
 
   /// Emit the RTTI descriptors for the builtin types.
   void EmitFundamentalRTTIDescriptors();
diff --git a/clang/lib/CodeGen/ModuleBuilder.cpp b/clang/lib/CodeGen/ModuleBuilder.cpp
index 4f1a82e0248..f85de0d07fa 100644
--- a/clang/lib/CodeGen/ModuleBuilder.cpp
+++ b/clang/lib/CodeGen/ModuleBuilder.cpp
@@ -211,11 +211,11 @@ namespace {
       Builder->EmitTentativeDefinition(D);
     }
 
-    void HandleVTable(CXXRecordDecl *RD, bool DefinitionRequired) override {
+    void HandleVTable(CXXRecordDecl *RD) override {
       if (Diags.hasErrorOccurred())
         return;
 
-      Builder->EmitVTable(RD, DefinitionRequired);
+      Builder->EmitVTable(RD);
     }
 
     void HandleLinkerOptionPragma(llvm::StringRef Opts) override {
diff --git a/clang/lib/Frontend/MultiplexConsumer.cpp b/clang/lib/Frontend/MultiplexConsumer.cpp
index 019882833d4..3c4fed1d18e 100644
--- a/clang/lib/Frontend/MultiplexConsumer.cpp
+++ b/clang/lib/Frontend/MultiplexConsumer.cpp
@@ -292,10 +292,9 @@ void MultiplexConsumer::CompleteTentativeDefinition(VarDecl *D) {
     Consumer->CompleteTentativeDefinition(D);
 }
 
-void MultiplexConsumer::HandleVTable(
-    CXXRecordDecl *RD, bool DefinitionRequired) {
+void MultiplexConsumer::HandleVTable(CXXRecordDecl *RD) {
   for (auto &Consumer : Consumers)
-    Consumer->HandleVTable(RD, DefinitionRequired);
+    Consumer->HandleVTable(RD);
 }
 
 ASTMutationListener *MultiplexConsumer::GetASTMutationListener() {
diff --git a/clang/lib/Sema/SemaDeclCXX.cpp b/clang/lib/Sema/SemaDeclCXX.cpp
index 510738ea816..54de4b97939 100644
--- a/clang/lib/Sema/SemaDeclCXX.cpp
+++ b/clang/lib/Sema/SemaDeclCXX.cpp
@@ -13122,7 +13122,8 @@ bool Sema::DefineUsedVTables() {
     DefinedAnything = true;
     MarkVirtualMembersReferenced(Loc, Class);
     CXXRecordDecl *Canonical = cast<CXXRecordDecl>(Class->getCanonicalDecl());
-    Consumer.HandleVTable(Class, VTablesUsed[Canonical]);
+    if (VTablesUsed[Canonical])
+      Consumer.HandleVTable(Class);
 
     // Optionally warn if we're emitting a weak vtable.
     if (Class->isExternallyVisible() &&