Fix <rdar://problem/5987482> clang on xcode: null dereference in Sema::ActOnMemberReferenceExpr.

In addition to fixing the crasher, this commit fixes further improves property lookup (by searching protocols of qualified interfaces..."NSObject <prot>").


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@52001 91177308-0d34-0410-b5e6-96231b3b80d8

include/clang/AST/DeclObjC.h

@@ -543,6 +543,8 @@ public:
   
   unsigned getNumInstanceMethods() const { return NumInstanceMethods; }
   unsigned getNumClassMethods() const { return NumClassMethods; }
+
+  ObjCPropertyDecl *FindPropertyDeclaration(IdentifierInfo *PropertyId) const;
   
   unsigned getNumPropertyDecl() const { return NumPropertyDecl; }
   

lib/AST/DeclObjC.cpp

@@ -157,6 +157,14 @@ ObjCPropertyDecl *
     if (property)
       return property;
   }
+  // Look through protocols.
+  for (ObjCInterfaceDecl::protocol_iterator I = protocol_begin(),
+       E = protocol_end(); I != E; ++I) {
+    ObjCProtocolDecl *Protocol = *I;
+    ObjCPropertyDecl *property = Protocol->FindPropertyDeclaration(PropertyId);
+    if (property)
+      return property;
+  }
   if (getSuperClass())
     return getSuperClass()->FindPropertyDeclaration(PropertyId);
   return 0;
@@ -397,6 +405,20 @@ ObjCCategoryDecl::FindPropertyDeclaration(IdentifierInfo *PropertyId) const {
   return 0;
 }
 
+/// FindPropertyDeclaration - Finds declaration of the property given its name
+/// in 'PropertyId' and returns it. It returns 0, if not found.
+///
+ObjCPropertyDecl *
+ObjCProtocolDecl::FindPropertyDeclaration(IdentifierInfo *PropertyId) const {
+  for (ObjCProtocolDecl::classprop_iterator I = classprop_begin(),
+       E = classprop_end(); I != E; ++I) {
+    ObjCPropertyDecl *property = *I;
+    if (property->getIdentifier() == PropertyId)
+      return property;
+  }
+  return 0;
+}
+
 ObjCIvarDecl *ObjCInterfaceDecl::lookupInstanceVariable(
   IdentifierInfo *ID, ObjCInterfaceDecl *&clsDeclared) {
   ObjCInterfaceDecl* ClassDecl = this;

lib/Sema/SemaExpr.cpp

@@ -602,10 +602,11 @@ ActOnMemberReferenceExpr(ExprTy *Base, SourceLocation OpLoc,
     return new ExtVectorElementExpr(ret, BaseExpr, Member, MemberLoc);
   } else if (BaseType->isObjCInterfaceType()) {
     ObjCInterfaceDecl *IFace;
-    if (isa<ObjCInterfaceType>(BaseType.getCanonicalType()))
-      IFace = dyn_cast<ObjCInterfaceType>(BaseType)->getDecl();
+    QualType CanonType = BaseType.getCanonicalType();
+    if (isa<ObjCInterfaceType>(CanonType))
+      IFace = dyn_cast<ObjCInterfaceType>(CanonType)->getDecl();
     else
-      IFace = dyn_cast<ObjCQualifiedInterfaceType>(BaseType)->getDecl();
+      IFace = dyn_cast<ObjCQualifiedInterfaceType>(CanonType)->getDecl();
     ObjCInterfaceDecl *clsDeclared;
     if (ObjCIvarDecl *IV = IFace->lookupInstanceVariable(&Member, clsDeclared))
       return new ObjCIvarRefExpr(IV, IV->getType(), MemberLoc, BaseExpr, 
@@ -614,10 +615,11 @@ ActOnMemberReferenceExpr(ExprTy *Base, SourceLocation OpLoc,
     PointerType *pointerType = static_cast<PointerType*>(BaseType.getTypePtr());
     BaseType = pointerType->getPointeeType();
     ObjCInterfaceDecl *IFace;
-    if (isa<ObjCInterfaceType>(BaseType.getCanonicalType()))
-      IFace = dyn_cast<ObjCInterfaceType>(BaseType)->getDecl();
+    QualType CanonType = BaseType.getCanonicalType();
+    if (isa<ObjCInterfaceType>(CanonType))
+      IFace = dyn_cast<ObjCInterfaceType>(CanonType)->getDecl();
     else
-      IFace = dyn_cast<ObjCQualifiedInterfaceType>(BaseType)->getDecl();
+      IFace = dyn_cast<ObjCQualifiedInterfaceType>(CanonType)->getDecl();
     ObjCInterfaceDecl *clsDeclared;
     if (ObjCIvarDecl *IV = IFace->lookupInstanceVariable(&Member, clsDeclared))
       return new ObjCIvarRefExpr(IV, IV->getType(), MemberLoc, BaseExpr, 
@@ -639,6 +641,15 @@ ActOnMemberReferenceExpr(ExprTy *Base, SourceLocation OpLoc,
       // void someMethod() { frameworkBundle.bundlePath = 0; }
       //
       ObjCPropertyDecl *PD = IFace->FindPropertyDeclaration(&Member);
+      
+      if (!PD) { // Lastly, check protocols on qualified interfaces.
+        if (ObjCQualifiedInterfaceType *QIT = 
+            dyn_cast<ObjCQualifiedInterfaceType>(CanonType)) {
+          for (unsigned i = 0; i < QIT->getNumProtocols(); i++)
+            if ((PD = QIT->getProtocols(i)->FindPropertyDeclaration(&Member)))
+              break;
+        }
+      }
       if (PD)
         return new ObjCPropertyRefExpr(PD, PD->getType(), MemberLoc, BaseExpr);
     }

test/Sema/objc-props-on-prots.m

@@ -0,0 +1,65 @@
+// RUN: clang -fsyntax-only -verify %s
+typedef signed char BOOL;
+@class NSInvocation, NSMethodSignature, NSCoder, NSString, NSEnumerator;
+
+@protocol NSObject
+- (BOOL) isEqual:(id) object;
+@end
+
+@protocol NSCoding
+- (void) encodeWithCoder:(NSCoder *) aCoder;
+@end
+
+@interface NSObject < NSObject > {} @end
+
+typedef float CGFloat;
+
+@interface NSResponder:NSObject < NSCoding > {} @end
+
+@class XCElementView;
+
+typedef struct _XCElementInset {} XCElementInset;
+
+@protocol XCElementP < NSObject >
+-(BOOL) vertical;
+@end
+
+@protocol XCElementDisplayDelegateP;
+@protocol XCElementTabMarkerP;
+
+typedef NSObject < XCElementTabMarkerP > XCElementTabMarker;
+
+@protocol XCElementTabberP < XCElementP >
+-(void) setMarker:(XCElementTabMarker *) marker;
+@end
+
+typedef NSObject < XCElementTabberP > XCElementTabber;
+
+@protocol XCElementTabMarkerP < NSObject >
+@property(nonatomic)
+BOOL variableSized;
+@end
+
+@protocol XCElementJustifierP < XCElementP >
+-(void) setHJustification:(CGFloat) hJust;
+@end
+
+typedef NSObject < XCElementJustifierP > XCElementJustifier;
+@interface XCElementImp:NSObject < XCElementP > {}
+@end
+
+@class XCElementImp;
+
+@interface XCElementTabberImp:XCElementImp < XCElementTabberP > {
+	XCElementTabMarker *_marker;
+}
+@end
+
+@implementation XCElementTabberImp 
+- (void) setMarker:(XCElementTabMarker *) marker {
+  if (_marker && _marker.variableSized) {
+  }
+}
+- vertical { return self; }
+- (BOOL)isEqual:x { return 1; }
+@end