From ddc181d2561b14b95e7b3afbacaa0e55d16ea733 Mon Sep 17 00:00:00 2001
From: Alexey Bataev <a.bataev@hotmail.com>
Date: Tue, 26 Feb 2019 20:52:16 +0000
Subject: [PATCH] [OPENMP]Delay emission for unsupported va_arg expression.

If the OpenMP device is NVPTX and va_arg is used, delay emission of the
error for va_arg unless it is used in the device code.

llvm-svn: 354925
---
 clang/lib/Sema/SemaExpr.cpp                   |  5 +++
 .../test/OpenMP/nvptx_va_arg_delayed_diags.c  | 40 +++++++++++++++++++
 2 files changed, 45 insertions(+)
 create mode 100644 clang/test/OpenMP/nvptx_va_arg_delayed_diags.c

diff --git a/clang/lib/Sema/SemaExpr.cpp b/clang/lib/Sema/SemaExpr.cpp
index 00b4cddc6b2c..e91115aec5bc 100644
--- a/clang/lib/Sema/SemaExpr.cpp
+++ b/clang/lib/Sema/SemaExpr.cpp
@@ -13909,6 +13909,11 @@ ExprResult Sema::BuildVAArgExpr(SourceLocation BuiltinLoc,
     }
   }
 
+  // NVPTX does not support va_arg expression.
+  if (getLangOpts().OpenMP && getLangOpts().OpenMPIsDevice &&
+      Context.getTargetInfo().getTriple().isNVPTX())
+    targetDiag(E->getBeginLoc(), diag::err_va_arg_in_device);
+
   // It might be a __builtin_ms_va_list. (But don't ever mark a va_arg()
   // as Microsoft ABI on an actual Microsoft platform, where
   // __builtin_ms_va_list and __builtin_va_list are the same.)
diff --git a/clang/test/OpenMP/nvptx_va_arg_delayed_diags.c b/clang/test/OpenMP/nvptx_va_arg_delayed_diags.c
new file mode 100644
index 000000000000..3420884d97b2
--- /dev/null
+++ b/clang/test/OpenMP/nvptx_va_arg_delayed_diags.c
@@ -0,0 +1,40 @@
+// RUN: %clang_cc1 -fopenmp -x c -triple i386-unknown-unknown -fopenmp-targets=nvptx-nvidia-cuda -emit-llvm-bc %s -o %t-x86-host.bc
+// RUN: %clang_cc1 -verify -fopenmp -x c -triple nvptx-unknown-unknown -fopenmp-targets=nvptx-nvidia-cuda %s -fopenmp-is-device -fopenmp-host-ir-file-path %t-x86-host.bc -fsyntax-only
+// RUN: %clang_cc1 -verify -DDIAGS -DIMMEDIATE -fopenmp -x c -triple nvptx-unknown-unknown -fopenmp-targets=nvptx-nvidia-cuda %s -fopenmp-is-device -fopenmp-host-ir-file-path %t-x86-host.bc -fsyntax-only
+// RUN: %clang_cc1 -verify -DDIAGS -DDELAYED -fopenmp -x c -triple nvptx-unknown-unknown -fopenmp-targets=nvptx-nvidia-cuda %s -fopenmp-is-device -fopenmp-host-ir-file-path %t-x86-host.bc -fsyntax-only
+// REQUIRES: x86-registered-target
+// REQUIRES: nvptx-registered-target
+
+#ifndef DIAGS
+// expected-no-diagnostics
+#endif // DIAGS
+
+#ifdef IMMEDIATE
+#pragma omp declare target
+#endif //IMMEDIATE
+void t1(int r, ...) {
+#ifdef DIAGS
+// expected-error@+4 {{CUDA device code does not support va_arg}}
+#endif // DIAGS
+  __builtin_va_list list;
+  __builtin_va_start(list, r);
+  (void)__builtin_va_arg(list, int);
+  __builtin_va_end(list);
+}
+
+#ifdef IMMEDIATE
+#pragma omp end declare target
+#endif //IMMEDIATE
+
+int main() {
+#ifdef DELAYED
+#pragma omp target
+#endif // DELAYED
+  {
+#ifdef DELAYED
+// expected-note@+2 {{called by 'main'}}
+#endif // DELAYED
+    t1(0);
+  }
+  return 0;
+}