In Sema, whenever we think that a function is going to cause a vtable to be generated, we mark any virtual implicit member functions as referenced.

llvm-svn: 90327

clang/include/clang/AST/DeclCXX.h

@@ -660,7 +660,7 @@ public:
   CXXConstructorDecl *getDefaultConstructor(ASTContext &Context);
 
   /// getDestructor - Returns the destructor decl for this class.
-  const CXXDestructorDecl *getDestructor(ASTContext &Context);
+  CXXDestructorDecl *getDestructor(ASTContext &Context);
 
   /// isLocalClass - If the class is a local class [class.local], returns
   /// the enclosing function declaration.

clang/lib/AST/DeclCXX.cpp

@@ -507,8 +507,7 @@ CXXRecordDecl::getDefaultConstructor(ASTContext &Context) {
   return 0;
 }
 
-const CXXDestructorDecl *
-CXXRecordDecl::getDestructor(ASTContext &Context) {
+CXXDestructorDecl *CXXRecordDecl::getDestructor(ASTContext &Context) {
   QualType ClassType = Context.getTypeDeclType(this);
 
   DeclarationName Name
@@ -519,7 +518,7 @@ CXXRecordDecl::getDestructor(ASTContext &Context) {
   llvm::tie(I, E) = lookup(Name);
   assert(I != E && "Did not find a destructor!");
 
-  const CXXDestructorDecl *Dtor = cast<CXXDestructorDecl>(*I);
+  CXXDestructorDecl *Dtor = cast<CXXDestructorDecl>(*I);
   assert(++I == E && "Found more than one destructor!");
 
   return Dtor;

clang/lib/AST/RecordLayoutBuilder.cpp

@@ -677,6 +677,11 @@ static const CXXMethodDecl *GetKeyFunction(const CXXRecordDecl *RD) {
     if (MD->isPure())
       continue;
     
+    // Ignore implicit member functions, they are always marked as inline, but
+    // they don't have a body until they're defined.
+    if (MD->isImplicit())
+      continue;
+    
     const FunctionDecl *fn;
     if (MD->getBody(fn) && !fn->isOutOfLine())
       continue;

clang/lib/Sema/Sema.h

@@ -1932,8 +1932,7 @@ public:
                                        QualType Argument);
 
   bool FindDeallocationFunction(SourceLocation StartLoc, CXXRecordDecl *RD, 
-                                DeclarationName Name, FunctionDecl* &Operator,
-                                bool Diagnose=true);
+                                DeclarationName Name, FunctionDecl* &Operator);
 
   /// ActOnCXXDelete - Parsed a C++ 'delete' expression
   virtual OwningExprResult ActOnCXXDelete(SourceLocation StartLoc,
@@ -2128,6 +2127,12 @@ public:
   /// as referenced.
   void MarkBaseAndMemberDestructorsReferenced(CXXDestructorDecl *Destructor);
 
+  /// MaybeMarkVirtualImplicitMembersReferenced - If the passed in method is the
+  /// key function of the record decl, will mark virtual member functions as 
+  /// referenced.
+  void MaybeMarkVirtualImplicitMembersReferenced(SourceLocation Loc, 
+                                                 CXXMethodDecl *MD);
+  
   void AddImplicitlyDeclaredMembersToClass(CXXRecordDecl *ClassDecl);
 
   virtual void ActOnMemInitializers(DeclPtrTy ConstructorDecl,
@@ -2160,7 +2165,7 @@ public:
   void CheckConstructor(CXXConstructorDecl *Constructor);
   QualType CheckDestructorDeclarator(Declarator &D,
                                      FunctionDecl::StorageClass& SC);
-  bool CheckDestructor(CXXDestructorDecl *Destructor, bool Diagnose=true);
+  bool CheckDestructor(CXXDestructorDecl *Destructor);
   void CheckConversionDeclarator(Declarator &D, QualType &R,
                                  FunctionDecl::StorageClass& SC);
   DeclPtrTy ActOnConversionDeclarator(CXXConversionDecl *Conversion);

clang/lib/Sema/SemaDecl.cpp

@@ -4085,12 +4085,14 @@ Sema::DeclPtrTy Sema::ActOnFinishFunctionBody(DeclPtrTy D, StmtArg BodyArg,
     if (!FD->isInvalidDecl())
       DiagnoseUnusedParameters(FD->param_begin(), FD->param_end());
 
-    // C++ [basic.def.odr]p2:
-    //   [...] A virtual member function is used if it is not pure. [...]
-    if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FD))
+    if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FD)) {
+      // C++ [basic.def.odr]p2:
+      //   [...] A virtual member function is used if it is not pure. [...]
       if (Method->isVirtual() && !Method->isPure())
         MarkDeclarationReferenced(Method->getLocation(), Method);
 
+      MaybeMarkVirtualImplicitMembersReferenced(Method->getLocation(), Method);
+    }
     assert(FD == getCurFunctionDecl() && "Function parsing confused");
   } else if (ObjCMethodDecl *MD = dyn_cast_or_null<ObjCMethodDecl>(dcl)) {
     assert(MD == getCurMethodDecl() && "Method parsing confused");

clang/lib/Sema/SemaDeclCXX.cpp

@@ -15,6 +15,7 @@
 #include "Lookup.h"
 #include "clang/AST/ASTConsumer.h"
 #include "clang/AST/ASTContext.h"
+#include "clang/AST/RecordLayout.h"
 #include "clang/AST/CXXInheritance.h"
 #include "clang/AST/DeclVisitor.h"
 #include "clang/AST/TypeOrdering.h"
@@ -2172,7 +2173,6 @@ void Sema::AddImplicitlyDeclaredMembersToClass(CXXRecordDecl *ClassDecl) {
     ClassDecl->addDecl(Destructor);
     
     AddOverriddenMethods(ClassDecl, Destructor);
-    CheckDestructor(Destructor, false);
   }
 }
 
@@ -2371,7 +2371,7 @@ void Sema::CheckConstructor(CXXConstructorDecl *Constructor) {
 
 /// CheckDestructor - Checks a fully-formed destructor for well-formedness, 
 /// issuing any diagnostics required. Returns true on error.
-bool Sema::CheckDestructor(CXXDestructorDecl *Destructor, bool Diagnose) {
+bool Sema::CheckDestructor(CXXDestructorDecl *Destructor) {
   CXXRecordDecl *RD = Destructor->getParent();
   
   if (Destructor->isVirtual()) {
@@ -2386,7 +2386,7 @@ bool Sema::CheckDestructor(CXXDestructorDecl *Destructor, bool Diagnose) {
     FunctionDecl *OperatorDelete = 0;
     DeclarationName Name = 
     Context.DeclarationNames.getCXXOperatorName(OO_Delete);
-    if (FindDeallocationFunction(Loc, RD, Name, OperatorDelete, Diagnose))
+    if (FindDeallocationFunction(Loc, RD, Name, OperatorDelete))
       return true;
     
     Destructor->setOperatorDelete(OperatorDelete);
@@ -3083,7 +3083,8 @@ void Sema::DefineImplicitDefaultConstructor(SourceLocation CurrentLocation,
   } else {
     Constructor->setUsed();
   }
-  return;
+
+  MaybeMarkVirtualImplicitMembersReferenced(CurrentLocation, Constructor);
 }
 
 void Sema::DefineImplicitDestructor(SourceLocation CurrentLocation,
@@ -4994,3 +4995,31 @@ Sema::ActOnCXXConditionDeclaration(Scope *S, Declarator &D) {
   VD->setDeclaredInCondition(true);
   return Dcl;
 }
+
+void Sema::MaybeMarkVirtualImplicitMembersReferenced(SourceLocation Loc,
+                                                     CXXMethodDecl *MD) {
+  // Ignore dependent types.
+  if (MD->isDependentContext())
+    return;
+  
+  CXXRecordDecl *RD = MD->getParent();
+  const ASTRecordLayout &Layout = Context.getASTRecordLayout(RD);
+  const CXXMethodDecl *KeyFunction = Layout.getKeyFunction();
+
+  if (!KeyFunction) {
+    // This record does not have a key function, so we assume that the vtable
+    // will be emitted when it's used by the constructor.
+    if (!isa<CXXConstructorDecl>(MD))
+      return;
+  } else if (KeyFunction->getCanonicalDecl() != MD->getCanonicalDecl()) {
+    // We don't have the right key function.
+    return;
+  }
+  
+  if (CXXDestructorDecl *Dtor = RD->getDestructor(Context)) {
+    if (Dtor->isImplicit() && Dtor->isVirtual())
+      MarkDeclarationReferenced(Loc, Dtor);
+  }
+  
+  // FIXME: Need to handle the virtual assignment operator here too.
+}

clang/lib/Sema/SemaExprCXX.cpp

@@ -775,8 +775,7 @@ void Sema::DeclareGlobalAllocationFunction(DeclarationName Name,
 
 bool Sema::FindDeallocationFunction(SourceLocation StartLoc, CXXRecordDecl *RD,
                                     DeclarationName Name,
-                                    FunctionDecl* &Operator,
-                                    bool Diagnose) {
+                                    FunctionDecl* &Operator) {
   LookupResult Found(*this, Name, StartLoc, LookupOrdinaryName);
   // Try to find operator delete/operator delete[] in class scope.
   LookupQualifiedName(Found, RD);
@@ -796,8 +795,6 @@ bool Sema::FindDeallocationFunction(SourceLocation StartLoc, CXXRecordDecl *RD,
   // We did find operator delete/operator delete[] declarations, but
   // none of them were suitable.
   if (!Found.empty()) {
-    if (!Diagnose)
-      return true;
     Diag(StartLoc, diag::err_no_suitable_delete_member_function_found)
       << Name << RD;
         

clang/test/SemaCXX/implicit-virtual-member-functions.cpp

@@ -0,0 +1,29 @@
+// RUN: clang-cc -fsyntax-only -verify %s
+struct A {
+  virtual ~A();
+};
+
+struct B : A { // expected-error {{no suitable member 'operator delete' in 'B'}}
+  virtual void f();
+
+  void operator delete (void *, int); // expected-note {{'operator delete' declared here}}
+};
+
+void B::f() { // expected-note {{implicit default destructor for 'struct B' first required here}}
+}
+
+struct C : A { // expected-error {{no suitable member 'operator delete' in 'C'}}
+  C();
+  void operator delete(void *, int); // expected-note {{'operator delete' declared here}}
+};
+
+C::C() { } // expected-note {{implicit default destructor for 'struct C' first required here}}
+
+struct D : A { // expected-error {{no suitable member 'operator delete' in 'D'}}
+  void operator delete(void *, int); // expected-note {{'operator delete' declared here}}
+};
+
+void f() {
+  new D; // expected-note {{implicit default destructor for 'struct D' first required here}}
+}
+