[OPENCL] Fix wrongly vla error for OpenCL array.

Summary:
OpenCL should support array with const value size length, those const varibale in global and constant address space and variable in constant address space.

Reviewers: Anastasia, yaxunl, bader

Subscribers: bader, cfe-commits

Differential Revision: http://reviews.llvm.org/D20090

llvm-svn: 271971

1 files changed, 4 insertions, 1 deletions

diff --git a/clang/lib/AST/ExprConstant.cpp b/clang/lib/AST/ExprConstant.cpp
index 8c24b0333e1..e14330cf60e 100644
--- a/clang/lib/AST/ExprConstant.cpp
+++ b/clang/lib/AST/ExprConstant.cpp
@@ -2745,7 +2745,10 @@ static CompleteObject findCompleteObject(EvalInfo &Info, const Expr *E,
       } else if (VD->isConstexpr()) {
         // OK, we can read this variable.
       } else if (BaseType->isIntegralOrEnumerationType()) {
-        if (!BaseType.isConstQualified()) {
+        // In OpenCL if a variable is in constant address space it is a const value.
+        if (!(BaseType.isConstQualified() ||
+              (Info.getLangOpts().OpenCL &&
+               BaseType.getAddressSpace() == LangAS::opencl_constant))) {
           if (Info.getLangOpts().CPlusPlus) {
             Info.Diag(E, diag::note_constexpr_ltor_non_const_int, 1) << VD;
             Info.Note(VD->getLocation(), diag::note_declared_at);