[OpenCL] Fix access qualifiers handling for typedefs

OpenCL s6.6: "Access qualifier must be used with image object arguments
of kernels and of user-defined functions [...] If no qualifier is
provided, read_only is assumed".

This does not define the behavior for image types used in typedef
declaration, but following the spec logic, we should allow access
qualifiers specification in typedefs, e.g.:

  typedef write_only image1d_t img1d_wo;

Unlike cv-qualifiers, user cannot add access qualifier to a typedef
type, i.e. this is not allowed:

  typedef image1d_t img1d; // note: previously declared 'read_only' here
  void foo(write_only img1d im) {} // error: multiple access qualifier

Patch by Andrew Savonichev.
Reviewers: Anastasia Stulova.

Differential revision: http://reviews.llvm.org/D20948

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@274858 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 2 insertions, 1 deletions

diff --git a/include/clang/Basic/Attr.td b/include/clang/Basic/Attr.td
index f5b31d0d73..51903cbf92 100644
--- a/include/clang/Basic/Attr.td
+++ b/include/clang/Basic/Attr.td
@@ -688,7 +688,8 @@ def OpenCLAccess : Attr {
   let Spellings = [Keyword<"__read_only">, Keyword<"read_only">,
                    Keyword<"__write_only">, Keyword<"write_only">,
                    Keyword<"__read_write">, Keyword<"read_write">];
-  let Subjects = SubjectList<[ParmVar], ErrorDiag>;
+  let Subjects = SubjectList<[ParmVar, TypedefName], ErrorDiag,
+                             "ExpectedParameterOrTypedef">;
   let Accessors = [Accessor<"isReadOnly", [Keyword<"__read_only">,
                                            Keyword<"read_only">]>,
                    Accessor<"isReadWrite", [Keyword<"__read_write">,