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

2 files changed, 52 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()
+}
+
diff --git a/clang/test/Sema/preserve-call-conv.c b/clang/test/Sema/preserve-call-conv.c
new file mode 100644
index 00000000000..f258f45ac58
--- /dev/null
+++ b/clang/test/Sema/preserve-call-conv.c
@@ -0,0 +1,35 @@
+// RUN: %clang_cc1 %s -fsyntax-only -triple x86_64-unknown-unknown -verify
+// RUN: %clang_cc1 %s -fsyntax-only -triple arm64-unknown-unknown -verify
+typedef void typedef_fun_t(int);
+
+void __attribute__((preserve_most)) foo(void *ptr) {
+}
+
+void __attribute__((preserve_most(1))) foo1(void *ptr) { // expected-error {{'preserve_most' attribute takes no arguments}}
+}
+
+void (__attribute__((preserve_most)) *pfoo1)(void *) = foo;
+
+void (__attribute__((cdecl)) *pfoo2)(void *) = foo; // expected-warning {{incompatible pointer types initializing 'void (*)(void *) __attribute__((cdecl))' with an expression of type 'void (void *) __attribute__((preserve_most))'}}
+void (*pfoo3)(void *) = foo; // expected-warning {{incompatible pointer types initializing 'void (*)(void *)' with an expression of type 'void (void *) __attribute__((preserve_most))'}}
+
+typedef_fun_t typedef_fun_foo; // expected-note {{previous declaration is here}}
+void __attribute__((preserve_most)) typedef_fun_foo(int x) { } // expected-error {{function declared 'preserve_most' here was previously declared without calling convention}}
+
+struct type_test_foo {} __attribute__((preserve_most));  // expected-warning {{'preserve_most' attribute only applies to functions and methods}}
+
+void __attribute__((preserve_all)) boo(void *ptr) {
+}
+
+void __attribute__((preserve_all(1))) boo1(void *ptr) { // expected-error {{'preserve_all' attribute takes no arguments}}
+}
+
+void (__attribute__((preserve_all)) *pboo1)(void *) = boo;
+
+void (__attribute__((cdecl)) *pboo2)(void *) = boo; // expected-warning {{incompatible pointer types initializing 'void (*)(void *) __attribute__((cdecl))' with an expression of type 'void (void *) __attribute__((preserve_all))'}}
+void (*pboo3)(void *) = boo; // expected-warning {{incompatible pointer types initializing 'void (*)(void *)' with an expression of type 'void (void *) __attribute__((preserve_all))'}}
+
+typedef_fun_t typedef_fun_boo; // expected-note {{previous declaration is here}}
+void __attribute__((preserve_all)) typedef_fun_boo(int x) { } // expected-error {{function declared 'preserve_all' here was previously declared without calling convention}}
+
+struct type_test_boo {} __attribute__((preserve_all));  // expected-warning {{'preserve_all' attribute only applies to functions and methods}}