Set calling convention for CUDA kernel

This patch sets target specific calling convention for CUDA kernels in IR.

Patch by Greg Rodgers.
Revised and lit test added by Yaxun Liu.

Differential Revision: https://reviews.llvm.org/D44747

llvm-svn: 328795

1 files changed, 11 insertions, 0 deletions

diff --git a/clang/lib/Sema/SemaExpr.cpp b/clang/lib/Sema/SemaExpr.cpp
index c0533f7cc7d..d87c21c0b17 100644
--- a/clang/lib/Sema/SemaExpr.cpp
+++ b/clang/lib/Sema/SemaExpr.cpp
@@ -25,6 +25,7 @@
 #include "clang/AST/ExprObjC.h"
 #include "clang/AST/ExprOpenMP.h"
 #include "clang/AST/RecursiveASTVisitor.h"
+#include "clang/AST/Type.h"
 #include "clang/AST/TypeLoc.h"
 #include "clang/Basic/PartialDiagnostic.h"
 #include "clang/Basic/SourceManager.h"
@@ -1657,6 +1658,16 @@ Sema::BuildDeclRefExpr(ValueDecl *D, QualType Ty, ExprValueKind VK,
       isa<VarDecl>(D) &&
       NeedToCaptureVariable(cast<VarDecl>(D), NameInfo.getLoc());
 
+  // Drop CUDA kernel calling convention since it is invisible to the user
+  // in DRE.
+  if (const auto *FT = Ty->getAs<FunctionType>()) {
+    if (FT->getCallConv() == CC_CUDAKernel) {
+      FT = Context.adjustFunctionType(FT,
+                                      FT->getExtInfo().withCallingConv(CC_C));
+      Ty = QualType(FT, Ty.getQualifiers().getAsOpaqueValue());
+    }
+  }
+
   DeclRefExpr *E;
   if (isa<VarTemplateSpecializationDecl>(D)) {
     VarTemplateSpecializationDecl *VarSpec =