[OpenCL] Allow zero assignment and comparisons between queue_t type variables

This change allows for zero assignment and comparison of queue_t
type variables, and extends null_queue.cl to test this.

Patch by Alistair Davies.

Differential Revision: https://reviews.llvm.org/D51727

llvm-svn: 342968

1 files changed, 11 insertions, 0 deletions

diff --git a/clang/lib/Sema/SemaExpr.cpp b/clang/lib/Sema/SemaExpr.cpp
index 5bf7098dfa2..e89e8a2e68f 100644
--- a/clang/lib/Sema/SemaExpr.cpp
+++ b/clang/lib/Sema/SemaExpr.cpp
@@ -8086,6 +8086,13 @@ Sema::CheckSingleAssignmentConstraints(QualType LHSType, ExprResult &CallerRHS,
     return Compatible;
   }
 
+  // OpenCL queue_t type assignment.
+  if (LHSType->isQueueT() && RHS.get()->isNullPointerConstant(
+                                 Context, Expr::NPC_ValueDependentIsNull)) {
+    RHS = ImpCastExprToType(RHS.get(), LHSType, CK_NullToPointer);
+    return Compatible;
+  }
+
   // This check seems unnatural, however it is necessary to ensure the proper
   // conversion of functions/arrays. If the conversion were done for all
   // DeclExpr's (created by ActOnIdExpression), it would mess up the unary
@@ -10423,6 +10430,10 @@ QualType Sema::CheckCompareOperands(ExprResult &LHS, ExprResult &RHS,
   }
 
   if (getLangOpts().OpenCLVersion >= 200) {
+    if (LHSType->isQueueT() && RHSType->isQueueT()) {
+      return computeResultTy();
+    }
+
     if (LHSIsNull && RHSType->isQueueT()) {
       LHS = ImpCastExprToType(LHS.get(), RHSType, CK_NullToPointer);
       return computeResultTy();