2 files changed, 14 insertions, 1 deletions
diff --git a/clang/lib/AST/Expr.cpp b/clang/lib/AST/Expr.cpp
index 9c3d623c163..456b87b64e0 100644
--- a/clang/lib/AST/Expr.cpp
+++ b/clang/lib/AST/Expr.cpp
@@ -425,7 +425,7 @@ Expr::isLvalueResult Expr::isLvalue(ASTContext &Ctx) const {
   }
   case BlockDeclRefExprClass: {
     const BlockDeclRefExpr *BDR = cast<BlockDeclRefExpr>(this);
-    if (BDR->isByRef() && isa<VarDecl>(BDR->getDecl()))
+    if (isa<VarDecl>(BDR->getDecl()))
       return LV_Valid;
     break;
   }
@@ -497,6 +497,15 @@ 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;
+  }
   return MLV_Valid;    
 }
 
diff --git a/clang/lib/Sema/SemaExpr.cpp b/clang/lib/Sema/SemaExpr.cpp
index 1a80283f826..e8b4d8cb4b3 100644
--- a/clang/lib/Sema/SemaExpr.cpp
+++ b/clang/lib/Sema/SemaExpr.cpp
@@ -2181,6 +2181,10 @@ inline QualType Sema::CheckAssignmentOperands( // C99 6.5.16.1
     Diag(loc, diag::err_typecheck_duplicate_vector_components_not_mlvalue,
          lex->getSourceRange());
     return QualType();
+  case Expr::MLV_NotBlockQualified:
+    Diag(loc, diag::err_block_decl_ref_not_modifiable_lvalue,
+         lex->getSourceRange());
+    return QualType();
   }
 
   AssignConvertType ConvTy;