Sema checking for incorrect placement of __block.  Radar 6441502


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@70452 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/include/clang/Basic/DiagnosticSemaKinds.td b/include/clang/Basic/DiagnosticSemaKinds.td
index bf70de9..3a33a06 100644
--- a/include/clang/Basic/DiagnosticSemaKinds.td
+++ b/include/clang/Basic/DiagnosticSemaKinds.td
@@ -1614,6 +1614,8 @@
   "function %0 declared 'noreturn' should not return">;
 def err_noreturn_block_has_return_expr : Error<
   "block declared 'noreturn' should not return">;
+def err_block_on_nonlocal : Error<
+  "__block attribute not allowed, only allowed on local variables">;
 
 def err_shufflevector_non_vector : Error<
   "first two arguments to __builtin_shufflevector must be vectors">;
diff --git a/lib/Sema/SemaDecl.cpp b/lib/Sema/SemaDecl.cpp
index 4d6a103..9e2bd44 100644
--- a/lib/Sema/SemaDecl.cpp
+++ b/lib/Sema/SemaDecl.cpp
@@ -1909,6 +1909,11 @@
     return NewVD->setInvalidDecl();
   }
 
+  if (!NewVD->hasLocalStorage() && NewVD->hasAttr<BlocksAttr>()) {
+    Diag(NewVD->getLocation(), diag::err_block_on_nonlocal);
+    return NewVD->setInvalidDecl();
+  }
+    
   if (PrevDecl) {
     Redeclaration = true;
     MergeVarDecl(NewVD, PrevDecl);
@@ -2818,6 +2823,10 @@
     IdResolver.AddDecl(New);
 
   ProcessDeclAttributes(New, D);
+
+  if (New->hasAttr<BlocksAttr>()) {
+    Diag(New->getLocation(), diag::err_block_on_nonlocal);
+  }
   return DeclPtrTy::make(New);
 }
 
@@ -4256,4 +4265,3 @@
   return DeclPtrTy::make(FileScopeAsmDecl::Create(Context, CurContext,
                                                   Loc, AsmString));
 }
-
diff --git a/test/Sema/block-misc.c b/test/Sema/block-misc.c
index d4b4088..397d3e5 100644
--- a/test/Sema/block-misc.c
+++ b/test/Sema/block-misc.c
@@ -146,3 +146,11 @@
 void test15() {
   foo(^{ return LESS; });	// expected-error {{incompatible block pointer types passing 'int (^)(void)', expected 'long (^)()'}}
 }
+
+__block int test16i;  // expected-error {{__block attribute not allowed, only allowed on local variables}}
+
+void test16(__block int i) { // expected-error {{__block attribute not allowed, only allowed on local variables}}
+  extern __block double extern_var; // expected-error {{__block attribute not allowed, only allowed on local variables}}
+  static __block char * pch; // expected-error {{__block attribute not allowed, only allowed on local variables}}
+}
+