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

2 files changed, 12 insertions, 11 deletions

diff --git a/lib/AST/Expr.cpp b/lib/AST/Expr.cpp
index f2553c3390..789fbc5ce1 100644
--- a/lib/AST/Expr.cpp
+++ b/lib/AST/Expr.cpp
@@ -781,7 +781,17 @@ Expr::isModifiableLvalueResult Expr::isModifiableLvalue(ASTContext &Ctx) const {
     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 @@ Expr::isModifiableLvalueResult Expr::isModifiableLvalue(ASTContext &Ctx) const {
     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) {
diff --git a/test/Sema/block-literal.c b/test/Sema/block-literal.c
index 290cef1fed..4890839b97 100644
--- a/test/Sema/block-literal.c
+++ b/test/Sema/block-literal.c
@@ -39,7 +39,7 @@ void test2() {
 	}
 
 foo:
-	takeclosure(^{ x = 4; });  // expected-error {{read-only variable is not assignable}}
+	takeclosure(^{ x = 4; });  // expected-error {{variable is not assignable (missing __block type specifier)}}
   __block y = 7; // expected-warning {{type specifier missing, defaults to 'int'}}
   takeclosure(^{ y = 8; });
 }