For MS ABI, emit dllexport friend functions defined inline in class

Summary: ...as that is apparently what MSVC does

Reviewers: rnk

Patch by Stephan Bergmann

Differential Revision: http://reviews.llvm.org/D15267

llvm-svn: 263738

clang/include/clang/AST/ASTConsumer.h

@@ -55,9 +55,9 @@ public:
   /// \returns true to continue parsing, or false to abort parsing.
   virtual bool HandleTopLevelDecl(DeclGroupRef D);
 
-  /// \brief This callback is invoked each time an inline method definition is
-  /// completed.
-  virtual void HandleInlineMethodDefinition(CXXMethodDecl *D) {}
+  /// \brief This callback is invoked each time an inline (method or friend)
+  /// function definition in a class is completed.
+  virtual void HandleInlineFunctionDefinition(FunctionDecl *D) {}
 
   /// HandleInterestingDecl - Handle the specified interesting declaration. This
   /// is called by the AST reader when deserializing things that might interest

clang/include/clang/Frontend/MultiplexConsumer.h

@@ -36,7 +36,7 @@ public:
   void Initialize(ASTContext &Context) override;
   void HandleCXXStaticMemberVarInstantiation(VarDecl *VD) override;
   bool HandleTopLevelDecl(DeclGroupRef D) override;
-  void HandleInlineMethodDefinition(CXXMethodDecl *D) override;
+  void HandleInlineFunctionDefinition(FunctionDecl *D) override;
   void HandleInterestingDecl(DeclGroupRef D) override;
   void HandleTranslationUnit(ASTContext &Ctx) override;
   void HandleTagDeclDefinition(TagDecl *D) override;

clang/include/clang/Sema/Sema.h

@@ -1773,7 +1773,7 @@ public:
   Decl *ActOnFinishFunctionBody(Decl *Decl, Stmt *Body);
   Decl *ActOnFinishFunctionBody(Decl *Decl, Stmt *Body, bool IsInstantiation);
   Decl *ActOnSkippedFunctionBody(Decl *Decl);
-  void ActOnFinishInlineMethodDef(CXXMethodDecl *D);
+  void ActOnFinishInlineFunctionDef(FunctionDecl *D);
 
   /// ActOnFinishDelayedAttribute - Invoked when we have finished parsing an
   /// attribute for which parsing is delayed.

clang/lib/CodeGen/CodeGenAction.cpp

@@ -123,14 +123,14 @@ namespace clang {
       return true;
     }
 
-    void HandleInlineMethodDefinition(CXXMethodDecl *D) override {
+    void HandleInlineFunctionDefinition(FunctionDecl *D) override {
       PrettyStackTraceDecl CrashInfo(D, SourceLocation(),
                                      Context->getSourceManager(),
-                                     "LLVM IR generation of inline method");
+                                     "LLVM IR generation of inline function");
       if (llvm::TimePassesIsEnabled)
         LLVMIRGeneration.startTimer();
 
-      Gen->HandleInlineMethodDefinition(D);
+      Gen->HandleInlineFunctionDefinition(D);
 
       if (llvm::TimePassesIsEnabled)
         LLVMIRGeneration.stopTimer();

clang/lib/CodeGen/ModuleBuilder.cpp

@@ -143,12 +143,22 @@ namespace {
       DeferredInlineMethodDefinitions.clear();
     }
 
-    void HandleInlineMethodDefinition(CXXMethodDecl *D) override {
+    void HandleInlineFunctionDefinition(FunctionDecl *D) override {
       if (Diags.hasErrorOccurred())
         return;
 
       assert(D->doesThisDeclarationHaveABody());
 
+      // Handle friend functions.
+      if (D->isInIdentifierNamespace(Decl::IDNS_OrdinaryFriend)) {
+        if (Ctx->getTargetInfo().getCXXABI().isMicrosoft())
+          Builder->EmitTopLevelDecl(D);
+        return;
+      }
+
+      // Otherwise, must be a method.
+      auto MD = cast<CXXMethodDecl>(D);
+
       // We may want to emit this definition. However, that decision might be
       // based on computing the linkage, and we have to defer that in case we
       // are inside of something that will change the method's final linkage,
@@ -157,13 +167,13 @@ namespace {
       //     void bar();
       //     void foo() { bar(); }
       //   } A;
-      DeferredInlineMethodDefinitions.push_back(D);
+      DeferredInlineMethodDefinitions.push_back(MD);
 
       // Provide some coverage mapping even for methods that aren't emitted.
       // Don't do this for templated classes though, as they may not be
       // instantiable.
-      if (!D->getParent()->getDescribedClassTemplate())
-        Builder->AddDeferredUnusedCoverageMapping(D);
+      if (!MD->getParent()->getDescribedClassTemplate())
+        Builder->AddDeferredUnusedCoverageMapping(MD);
     }
 
     /// HandleTagDeclDefinition - This callback is invoked each time a TagDecl

clang/lib/Frontend/MultiplexConsumer.cpp

@@ -272,9 +272,9 @@ bool MultiplexConsumer::HandleTopLevelDecl(DeclGroupRef D) {
   return Continue;
 }
 
-void MultiplexConsumer::HandleInlineMethodDefinition(CXXMethodDecl *D) {
+void MultiplexConsumer::HandleInlineFunctionDefinition(FunctionDecl *D) {
   for (auto &Consumer : Consumers)
-    Consumer->HandleInlineMethodDefinition(D);
+    Consumer->HandleInlineFunctionDefinition(D);
 }
 
 void MultiplexConsumer::HandleCXXStaticMemberVarInstantiation(VarDecl *VD) {

clang/lib/Parse/ParseCXXInlineMethods.cpp

@@ -564,8 +564,10 @@ void Parser::ParseLexedMethodDef(LexedMethod &LM) {
   if (Tok.is(tok::eof) && Tok.getEofData() == LM.D)
     ConsumeAnyToken();
 
-  if (CXXMethodDecl *MD = dyn_cast_or_null<CXXMethodDecl>(LM.D))
-    Actions.ActOnFinishInlineMethodDef(MD);
+  if (auto *FD = dyn_cast_or_null<FunctionDecl>(LM.D))
+    if (isa<CXXMethodDecl>(FD) ||
+        FD->isInIdentifierNamespace(Decl::IDNS_OrdinaryFriend))
+      Actions.ActOnFinishInlineFunctionDef(FD);
 }
 
 /// ParseLexedMemberInitializers - We finished parsing the member specification

clang/lib/Sema/SemaDecl.cpp

@@ -10872,8 +10872,8 @@ Sema::ActOnStartOfFunctionDef(Scope *FnBodyScope, Declarator &D,
   return ActOnStartOfFunctionDef(FnBodyScope, DP, SkipBody);
 }
 
-void Sema::ActOnFinishInlineMethodDef(CXXMethodDecl *D) {
-  Consumer.HandleInlineMethodDefinition(D);
+void Sema::ActOnFinishInlineFunctionDef(FunctionDecl *D) {
+  Consumer.HandleInlineFunctionDefinition(D);
 }
 
 static bool ShouldWarnAboutMissingPrototype(const FunctionDecl *FD, 

clang/test/CodeGenCXX/dllexport.cpp

@@ -255,9 +255,11 @@ __declspec(dllexport) void redecl2();
 // GNU-DAG: define dllexport void @_Z7friend1v()
 // MSC-DAG: define dllexport void @"\01?friend2@@YAXXZ"()
 // GNU-DAG: define dllexport void @_Z7friend2v()
+// MSC-DAG: define weak_odr dllexport void @"\01?friend3@@YAXXZ"()
 struct FuncFriend {
   friend __declspec(dllexport) void friend1();
   friend __declspec(dllexport) void friend2();
+  friend __declspec(dllexport) void friend3() {}
 };
 __declspec(dllexport) void friend1() {}
                       void friend2() {}