Patch to supprt case of readonly property being

assigned to when it has user declared setter method
defined in the class implementation (but no declaration in
the class itself).

llvm-svn: 62098

3 files changed, 72 insertions, 1 deletions

diff --git a/clang/lib/Sema/Sema.h b/clang/lib/Sema/Sema.h
index 4db6f646b6a..f098372d97f 100644
--- a/clang/lib/Sema/Sema.h
+++ b/clang/lib/Sema/Sema.h
@@ -538,6 +538,9 @@ public:
                                    ObjCMethodDecl *IntfMethod);
 
   NamespaceDecl *GetStdNamespace();
+  
+  bool isPropertyReadonly(ObjCPropertyDecl *PropertyDecl,
+                          ObjCInterfaceDecl *IDecl) const;
                            
   /// CheckProtocolMethodDefs - This routine checks unimplemented
   /// methods declared in protocol, and those referenced by it.
diff --git a/clang/lib/Sema/SemaDeclObjC.cpp b/clang/lib/Sema/SemaDeclObjC.cpp
index c4b085dc1eb..afcf45622b9 100644
--- a/clang/lib/Sema/SemaDeclObjC.cpp
+++ b/clang/lib/Sema/SemaDeclObjC.cpp
@@ -699,6 +699,51 @@ void Sema::WarnConflictingTypedMethods(ObjCMethodDecl *ImpMethodDecl,
   }
 }
 
+/// isPropertyReadonly - Return true if property is readonly, by searching
+/// for the property in the class and in its categories and implementations
+///
+bool Sema::isPropertyReadonly(ObjCPropertyDecl *PDecl,
+                              ObjCInterfaceDecl *IDecl) const {
+  // by far the most common case.
+  if (!PDecl->isReadOnly())
+    return false;
+  // Even if property is ready only, if interface has a user defined setter, 
+  // it is not considered read only.
+  if (IDecl->getInstanceMethod(PDecl->getSetterName()))
+    return false;
+  
+  // Main class has the property as 'readonly'. Must search
+  // through the category list to see if the property's 
+  // attribute has been over-ridden to 'readwrite'.
+  for (ObjCCategoryDecl *Category = IDecl->getCategoryList();
+       Category; Category = Category->getNextClassCategory()) {
+    // Even if property is ready only, if a category has a user defined setter, 
+    // it is not considered read only. 
+    if (Category->getInstanceMethod(PDecl->getSetterName()))
+      return false;
+    ObjCPropertyDecl *P = 
+    Category->FindPropertyDeclaration(PDecl->getIdentifier());
+    if (P && !P->isReadOnly())
+      return false;
+  }
+  
+  // Also, check for definition of a setter method in the implementation if
+  // all else failed.
+  if (ObjCMethodDecl *OMD = dyn_cast<ObjCMethodDecl>(CurContext)) {
+    if (ObjCImplementationDecl *IMD = 
+        dyn_cast<ObjCImplementationDecl>(OMD->getDeclContext())) {
+      if (IMD->getInstanceMethod(PDecl->getSetterName()))
+        return false;
+    }
+    else if (ObjCCategoryImplDecl *CIMD = 
+             dyn_cast<ObjCCategoryImplDecl>(OMD->getDeclContext())) {
+      if (CIMD->getInstanceMethod(PDecl->getSetterName()))
+        return false;
+    }
+  }
+  return true;
+}
+
 /// FIXME: Type hierarchies in Objective-C can be deep. We could most
 /// likely improve the efficiency of selector lookups and type
 /// checking by associating with each protocol / interface / category
diff --git a/clang/lib/Sema/SemaExpr.cpp b/clang/lib/Sema/SemaExpr.cpp
index bf04042ef8a..d3d3d3556c4 100644
--- a/clang/lib/Sema/SemaExpr.cpp
+++ b/clang/lib/Sema/SemaExpr.cpp
@@ -2920,10 +2920,33 @@ inline QualType Sema::CheckLogicalOperands( // C99 6.5.[13,14]
   return InvalidOperands(Loc, lex, rex);
 }
 
+/// IsReadonlyProperty - Verify that otherwise a valid l-value expression
+/// is a read-only property; return true if so. A readonly property expression
+/// depends on various declarations and thus must be treated specially.
+///
+static bool IsReadonlyProperty(Expr *E, Sema &S) 
+{
+  if (E->getStmtClass() == Expr::ObjCPropertyRefExprClass) {
+    const ObjCPropertyRefExpr* PropExpr = cast<ObjCPropertyRefExpr>(E);
+    if (ObjCPropertyDecl *PDecl = PropExpr->getProperty()) {
+      QualType BaseType = PropExpr->getBase()->getType();
+      if (const PointerType *PTy = BaseType->getAsPointerType())
+        if (const ObjCInterfaceType *IFTy = 
+            PTy->getPointeeType()->getAsObjCInterfaceType())
+          if (ObjCInterfaceDecl *IFace = IFTy->getDecl())
+            if (S.isPropertyReadonly(PDecl, IFace))
+              return true;
+    }
+  }
+  return false;
+}
+
 /// CheckForModifiableLvalue - Verify that E is a modifiable lvalue.  If not,
 /// emit an error and return true.  If so, return false.
 static bool CheckForModifiableLvalue(Expr *E, SourceLocation Loc, Sema &S) {
-  Expr::isModifiableLvalueResult IsLV = E->isModifiableLvalue(S.Context); 
+  Expr::isModifiableLvalueResult IsLV = E->isModifiableLvalue(S.Context);
+  if (IsLV == Expr::MLV_Valid && IsReadonlyProperty(E, S))
+    IsLV = Expr::MLV_ReadonlyProperty;
   if (IsLV == Expr::MLV_Valid)
     return false;