Adjust isModifiableLvalue to give a slightly more useful diagnostic for 
attempting to illegally modify a BlockDeclRefExpr.



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@67491 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/AST/Expr.cpp b/lib/AST/Expr.cpp
index f2553c3..789fbc5 100644
--- a/lib/AST/Expr.cpp
+++ b/lib/AST/Expr.cpp
@@ -781,7 +781,17 @@
     return MLV_InvalidExpression;
   case LV_MemberFunction: return MLV_MemberFunction;
   }
-  
+
+  // The following is illegal:
+  //   void takeclosure(void (^C)(void));
+  //   void func() { int x = 1; takeclosure(^{ x = 7; }); }
+  //
+  if (getStmtClass() == BlockDeclRefExprClass) {
+    const BlockDeclRefExpr *BDR = cast<BlockDeclRefExpr>(this);
+    if (!BDR->isByRef() && isa<VarDecl>(BDR->getDecl()))
+      return MLV_NotBlockQualified;
+  }
+
   QualType CT = Ctx.getCanonicalType(getType());
   
   if (CT.isConstQualified())
@@ -795,15 +805,6 @@
     if (r->hasConstFields()) 
       return MLV_ConstQualified;
   }
-  // The following is illegal:
-  //   void takeclosure(void (^C)(void));
-  //   void func() { int x = 1; takeclosure(^{ x = 7 }); }
-  //
-  if (getStmtClass() == BlockDeclRefExprClass) {
-    const BlockDeclRefExpr *BDR = cast<BlockDeclRefExpr>(this);
-    if (!BDR->isByRef() && isa<VarDecl>(BDR->getDecl()))
-      return MLV_NotBlockQualified;
-  }
   
   // Assigning to an 'implicit' property?
   else if (getStmtClass() == ObjCKVCRefExprClass) {