Add attributes for preserve_mostcc/preserve_allcc calling conventions to the C/C++ front-end

Till now, preserve_mostcc/preserve_allcc calling convention attributes were only
available at the LLVM IR level. This patch adds attributes for
preserve_mostcc/preserve_allcc calling conventions to the C/C++ front-end.

The code was mostly written by Juergen Ributzka.
I just added support for the AArch64 target and tests.

Differential Revision: http://reviews.llvm.org/D18025

llvm-svn: 263647

1 files changed, 17 insertions, 0 deletions

diff --git a/clang/test/CodeGen/preserve-call-conv.c b/clang/test/CodeGen/preserve-call-conv.c
new file mode 100644
index 00000000000..6e91a8489b4
--- /dev/null
+++ b/clang/test/CodeGen/preserve-call-conv.c
@@ -0,0 +1,17 @@
+// RUN: %clang_cc1 -triple x86_64-unknown-unknown -emit-llvm < %s | FileCheck %s
+// RUN: %clang_cc1 -triple arm64-unknown-unknown -emit-llvm < %s | FileCheck %s
+
+// Check that the preserve_most calling convention attribute at the source level
+// is lowered to the corresponding calling convention attrribute at the LLVM IR
+// level.
+void foo() __attribute__((preserve_most)) {
+  // CHECK-LABEL: define preserve_mostcc void @foo()
+}
+
+// Check that the preserve_most calling convention attribute at the source level
+// is lowered to the corresponding calling convention attrribute at the LLVM IR
+// level.
+void boo() __attribute__((preserve_all)) {
+  // CHECK-LABEL: define preserve_allcc void @boo()
+}
+