Always diagnose and complain about problems in

ResolveAddressOfOverloadedFunction when asked to complain. Previously,
we had some weird handshake where ResolveAddressOfOverloadedFunction
expected its caller to handle some of the diagnostics but not others,
and yet there was no way for the caller to know which case we were
in. Eliminate this madness, fixing <rdar://problem/7765884>.

llvm-svn: 101312

3 files changed, 89 insertions, 69 deletions

diff --git a/clang/lib/Sema/SemaCXXCast.cpp b/clang/lib/Sema/SemaCXXCast.cpp
index 11c8e6ddab5..37df2a60005 100644
--- a/clang/lib/Sema/SemaCXXCast.cpp
+++ b/clang/lib/Sema/SemaCXXCast.cpp
@@ -809,15 +809,17 @@ TryStaticMemberPointerUpcast(Sema &Self, Expr *&SrcExpr, QualType SrcType,
 
   bool WasOverloadedFunction = false;
   DeclAccessPair FoundOverload;
-  if (FunctionDecl *Fn
-        = Self.ResolveAddressOfOverloadedFunction(SrcExpr, DestType, false,
-                                                  FoundOverload)) {
-    CXXMethodDecl *M = cast<CXXMethodDecl>(Fn);
-    SrcType = Self.Context.getMemberPointerType(Fn->getType(),
-                    Self.Context.getTypeDeclType(M->getParent()).getTypePtr());
-    WasOverloadedFunction = true;
+  if (SrcExpr->getType() == Self.Context.OverloadTy) {
+    if (FunctionDecl *Fn
+          = Self.ResolveAddressOfOverloadedFunction(SrcExpr, DestType, false,
+                                                    FoundOverload)) {
+      CXXMethodDecl *M = cast<CXXMethodDecl>(Fn);
+      SrcType = Self.Context.getMemberPointerType(Fn->getType(),
+                      Self.Context.getTypeDeclType(M->getParent()).getTypePtr());
+      WasOverloadedFunction = true;
+    }
   }
-
+  
   const MemberPointerType *SrcMemPtr = SrcType->getAs<MemberPointerType>();
   if (!SrcMemPtr) {
     msg = diag::err_bad_static_cast_member_pointer_nonmp;
diff --git a/clang/lib/Sema/SemaOverload.cpp b/clang/lib/Sema/SemaOverload.cpp
index e039669257b..53e05eed60a 100644
--- a/clang/lib/Sema/SemaOverload.cpp
+++ b/clang/lib/Sema/SemaOverload.cpp
@@ -613,31 +613,36 @@ Sema::IsStandardConversion(Expr* From, QualType ToType,
     // type "pointer to T." The result is a pointer to the
     // function. (C++ 4.3p1).
     FromType = Context.getPointerType(FromType);
-  } else if (FunctionDecl *Fn
-               = ResolveAddressOfOverloadedFunction(From, ToType, false,
-                                                    AccessPair)) {
-    // Address of overloaded function (C++ [over.over]).
-    SCS.First = ICK_Function_To_Pointer;
-
-    // We were able to resolve the address of the overloaded function,
-    // so we can convert to the type of that function.
-    FromType = Fn->getType();
-    if (ToType->isLValueReferenceType())
-      FromType = Context.getLValueReferenceType(FromType);
-    else if (ToType->isRValueReferenceType())
-      FromType = Context.getRValueReferenceType(FromType);
-    else if (ToType->isMemberPointerType()) {
-      // Resolve address only succeeds if both sides are member pointers,
-      // but it doesn't have to be the same class. See DR 247.
-      // Note that this means that the type of &Derived::fn can be
-      // Ret (Base::*)(Args) if the fn overload actually found is from the
-      // base class, even if it was brought into the derived class via a
-      // using declaration. The standard isn't clear on this issue at all.
-      CXXMethodDecl *M = cast<CXXMethodDecl>(Fn);
-      FromType = Context.getMemberPointerType(FromType,
-                    Context.getTypeDeclType(M->getParent()).getTypePtr());
-    } else
-      FromType = Context.getPointerType(FromType);
+  } else if (From->getType() == Context.OverloadTy) {
+    if (FunctionDecl *Fn
+          = ResolveAddressOfOverloadedFunction(From, ToType, false, 
+                                               AccessPair)) {
+      // Address of overloaded function (C++ [over.over]).
+      SCS.First = ICK_Function_To_Pointer;
+
+      // We were able to resolve the address of the overloaded function,
+      // so we can convert to the type of that function.
+      FromType = Fn->getType();
+      if (ToType->isLValueReferenceType())
+        FromType = Context.getLValueReferenceType(FromType);
+      else if (ToType->isRValueReferenceType())
+        FromType = Context.getRValueReferenceType(FromType);
+      else if (ToType->isMemberPointerType()) {
+        // Resolve address only succeeds if both sides are member pointers,
+        // but it doesn't have to be the same class. See DR 247.
+        // Note that this means that the type of &Derived::fn can be
+        // Ret (Base::*)(Args) if the fn overload actually found is from the
+        // base class, even if it was brought into the derived class via a
+        // using declaration. The standard isn't clear on this issue at all.
+        CXXMethodDecl *M = cast<CXXMethodDecl>(Fn);
+        FromType = Context.getMemberPointerType(FromType,
+                      Context.getTypeDeclType(M->getParent()).getTypePtr());
+      } else {
+        FromType = Context.getPointerType(FromType);
+      }
+    } else {
+      return false;
+    }
   } else {
     // We don't require any conversions for the first step.
     SCS.First = ICK_Identity;
@@ -5295,15 +5300,6 @@ Sema::ResolveAddressOfOverloadedFunction(Expr *From, QualType ToType,
     IsMember = true;
   }
 
-  // We only look at pointers or references to functions.
-  FunctionType = Context.getCanonicalType(FunctionType).getUnqualifiedType();
-  if (!FunctionType->isFunctionType())
-    return 0;
-
-  // Find the actual overloaded function declaration.
-  if (From->getType() != Context.OverloadTy)
-    return 0;
-
   // C++ [over.over]p1:
   //   [...] [Note: any redundant set of parentheses surrounding the
   //   overloaded function name is ignored (5.1). ]
@@ -5316,6 +5312,18 @@ Sema::ResolveAddressOfOverloadedFunction(Expr *From, QualType ToType,
     OvlExpr->getExplicitTemplateArgs().copyInto(ETABuffer);
     ExplicitTemplateArgs = &ETABuffer;
   }
+  
+  // We expect a pointer or reference to function, or a function pointer.
+  FunctionType = Context.getCanonicalType(FunctionType).getUnqualifiedType();
+  if (!FunctionType->isFunctionType()) {
+    if (Complain)
+      Diag(From->getLocStart(), diag::err_addr_ovl_not_func_ptrref)
+        << OvlExpr->getName() << ToType;
+    
+    return 0;
+  }
+
+  assert(From->getType() == Context.OverloadTy);
 
   // Look through all of the overloaded functions, searching for one
   // whose type matches exactly.
@@ -5397,9 +5405,19 @@ Sema::ResolveAddressOfOverloadedFunction(Expr *From, QualType ToType,
   }
 
   // If there were 0 or 1 matches, we're done.
-  if (Matches.empty())
+  if (Matches.empty()) {
+    if (Complain) {
+      Diag(From->getLocStart(), diag::err_addr_ovl_no_viable)
+        << OvlExpr->getName() << FunctionType;
+      for (UnresolvedSetIterator I = OvlExpr->decls_begin(),
+                                 E = OvlExpr->decls_end(); 
+           I != E; ++I)
+        if (FunctionDecl *F = dyn_cast<FunctionDecl>((*I)->getUnderlyingDecl()))
+          NoteOverloadCandidate(F);
+    }
+    
     return 0;
-  else if (Matches.size() == 1) {
+  } else if (Matches.size() == 1) {
     FunctionDecl *Result = Matches[0].second;
     FoundResult = Matches[0].first;
     MarkDeclarationReferenced(From->getLocStart(), Result);
diff --git a/clang/lib/Sema/SemaTemplate.cpp b/clang/lib/Sema/SemaTemplate.cpp
index 28d6f0a40aa..65e0e5e95e8 100644
--- a/clang/lib/Sema/SemaTemplate.cpp
+++ b/clang/lib/Sema/SemaTemplate.cpp
@@ -2368,14 +2368,8 @@ CheckTemplateArgumentAddressOfObjectOrFunction(Sema &S,
     DRE = dyn_cast<DeclRefExpr>(Arg);
 
   if (!DRE) {
-    if (S.Context.hasSameUnqualifiedType(ArgType, S.Context.OverloadTy)) {
-      S.Diag(Arg->getLocStart(), 
-             diag::err_template_arg_unresolved_overloaded_function)
-        << ParamType << Arg->getSourceRange();
-    } else {
-      S.Diag(Arg->getLocStart(), diag::err_template_arg_not_decl_ref)
-        << Arg->getSourceRange();
-    }
+    S.Diag(Arg->getLocStart(), diag::err_template_arg_not_decl_ref)
+      << Arg->getSourceRange();
     S.Diag(Param->getLocation(), diag::note_template_param_here);
     return true;
   }
@@ -2848,16 +2842,19 @@ bool Sema::CheckTemplateArgument(NonTypeTemplateParmDecl *Param,
        ParamType->getAs<MemberPointerType>()->getPointeeType()
          ->isFunctionType())) {
 
-    if (FunctionDecl *Fn = ResolveAddressOfOverloadedFunction(Arg, ParamType, 
-                                                              true,
-                                                              FoundResult)) {
-      if (DiagnoseUseOfDecl(Fn, Arg->getSourceRange().getBegin()))
-        return true;
+    if (Arg->getType() == Context.OverloadTy) {
+      if (FunctionDecl *Fn = ResolveAddressOfOverloadedFunction(Arg, ParamType, 
+                                                                true,
+                                                                FoundResult)) {
+        if (DiagnoseUseOfDecl(Fn, Arg->getSourceRange().getBegin()))
+          return true;
 
-      Arg = FixOverloadedFunctionReference(Arg, FoundResult, Fn);
-      ArgType = Arg->getType();
+        Arg = FixOverloadedFunctionReference(Arg, FoundResult, Fn);
+        ArgType = Arg->getType();
+      } else
+        return true;
     }
-
+        
     if (!ParamType->isMemberPointerType())
       return CheckTemplateArgumentAddressOfObjectOrFunction(*this, Param,
                                                             ParamType, 
@@ -2902,17 +2899,20 @@ bool Sema::CheckTemplateArgument(NonTypeTemplateParmDecl *Param,
     assert(ParamRefType->getPointeeType()->isObjectType() &&
            "Only object references allowed here");
 
-    if (FunctionDecl *Fn = ResolveAddressOfOverloadedFunction(Arg, 
-                                               ParamRefType->getPointeeType(), 
-                                                              true,
-                                                              FoundResult)) {
-      if (DiagnoseUseOfDecl(Fn, Arg->getSourceRange().getBegin()))
-        return true;
+    if (Arg->getType() == Context.OverloadTy) {
+      if (FunctionDecl *Fn = ResolveAddressOfOverloadedFunction(Arg, 
+                                                 ParamRefType->getPointeeType(), 
+                                                                true,
+                                                                FoundResult)) {
+        if (DiagnoseUseOfDecl(Fn, Arg->getSourceRange().getBegin()))
+          return true;
 
-      Arg = FixOverloadedFunctionReference(Arg, FoundResult, Fn);
-      ArgType = Arg->getType();
+        Arg = FixOverloadedFunctionReference(Arg, FoundResult, Fn);
+        ArgType = Arg->getType();
+      } else
+        return true;
     }
-
+    
     return CheckTemplateArgumentAddressOfObjectOrFunction(*this, Param, 
                                                           ParamType,
                                                           Arg, Converted);