Improve diagnostics when property names an object type of

a forward class. // rdar://8851803

llvm-svn: 125699

3 files changed, 30 insertions, 0 deletions

diff --git a/clang/include/clang/Basic/DiagnosticSemaKinds.td b/clang/include/clang/Basic/DiagnosticSemaKinds.td
index 9ccbf1e1f49..644b509e40e 100644
--- a/clang/include/clang/Basic/DiagnosticSemaKinds.td
+++ b/clang/include/clang/Basic/DiagnosticSemaKinds.td
@@ -2567,6 +2567,8 @@ def err_getter_not_found : Error<
   "expected getter method not found on object of type %0">;
 def err_property_not_found_forward_class : Error<
   "property %0 cannot be found in forward class object %1">;
+def err_property_not_as_forward_class : Error<
+  "property %0 names an object of forward class type in class object %1">;
 def note_forward_class : Note<
   "forward class is declared here">;
 def err_duplicate_property : Error<
diff --git a/clang/lib/Sema/SemaExprObjC.cpp b/clang/lib/Sema/SemaExprObjC.cpp
index 11fa9eb0b42..c41327e2846 100644
--- a/clang/lib/Sema/SemaExprObjC.cpp
+++ b/clang/lib/Sema/SemaExprObjC.cpp
@@ -520,6 +520,22 @@ HandleExprPropertyRefExpr(const ObjCObjectPointerType *OPT,
     return HandleExprPropertyRefExpr(OPT, BaseExpr, TypoResult, MemberLoc,
                                      SuperLoc, SuperType, Super);
   }
+  ObjCInterfaceDecl *ClassDeclared;
+  if (ObjCIvarDecl *Ivar = 
+      IFace->lookupInstanceVariable(Member, ClassDeclared)) {
+    QualType T = Ivar->getType();
+    if (const ObjCObjectPointerType * OBJPT = 
+        T->getAsObjCInterfacePointerType()) {
+      const ObjCInterfaceType *IFaceT = OBJPT->getInterfaceType();
+      if (ObjCInterfaceDecl *IFace = IFaceT->getDecl())
+        if (IFace->isForwardDecl()) {
+          Diag(MemberLoc, diag::err_property_not_as_forward_class)
+          << MemberName << QualType(OPT, 0);
+          Diag(IFace->getLocation(), diag::note_forward_class);
+          return ExprError();
+        }
+    }
+  }
   
   Diag(MemberLoc, diag::err_property_not_found)
     << MemberName << QualType(OPT, 0);
diff --git a/clang/test/SemaObjC/property-missing.m b/clang/test/SemaObjC/property-missing.m
index 6ce0beac51c..6b794fb02f3 100644
--- a/clang/test/SemaObjC/property-missing.m
+++ b/clang/test/SemaObjC/property-missing.m
@@ -20,3 +20,15 @@ void f3(id o)
   o.foo; // expected-error{{property 'foo' not found on object of type 'id'}}
 }
 
+// rdar://8851803
+@class SomeOtherClass; // expected-note {{forward class is declared here}}
+
+@interface MyClass {
+    SomeOtherClass *someOtherObject;
+}
+@end
+
+void foo(MyClass *myObject) {
+	myObject.someOtherObject.someProperty = 0; // expected-error {{property 'someOtherObject' names an object of forward class type in class object 'MyClass *'}}
+}
+