Change the analyzer to recognize (but ignore) assignments to isa. Fixes PR 6302.

llvm-svn: 99904

clang/lib/Checker/GRExprEngine.cpp

@@ -897,6 +897,11 @@ void GRExprEngine::VisitLValue(Expr* Ex, ExplodedNode* Pred,
       return;
     }
 
+    case Stmt::ObjCIsaExprClass:
+      // FIXME: Do something more intelligent with 'x->isa = ...'.
+      //  For now, just ignore the assignment.
+      return;
+
     case Stmt::ObjCPropertyRefExprClass:
     case Stmt::ObjCImplicitSetterGetterRefExprClass:
       // FIXME: Property assignments are lvalues, but not really "locations".

clang/test/Analysis/misc-ps-region-store.m

@@ -910,3 +910,13 @@ int rdar_7770737_pos(void)
   struct rdar_7770737_s f = { .p = (intptr_t)&x };
   return x; // expected-warning{{Undefined or garbage value returned to caller}}
 }
+
+//===----------------------------------------------------------------------===//
+// Test handling of the implicit 'isa' field.  For now we don't do anything
+// interesting.
+//===----------------------------------------------------------------------===//
+
+void pr6302(id x, Class y) {
+  // This previously crashed the analyzer (reported in PR 6302)
+  x->isa  = y;
+}