Implement the __builtin_call_with_static_chain GNU extension.

The extension has the following syntax:

  __builtin_call_with_static_chain(Call, Chain)
  where Call must be a function call expression and Chain must be of pointer type

This extension performs a function call Call with a static chain pointer
Chain passed to the callee in a designated register. This is useful for
calling foreign language functions whose ABI uses static chain pointers
(e.g. to implement closures).

Differential Revision: http://reviews.llvm.org/D6332

llvm-svn: 224167

1 files changed, 39 insertions, 0 deletions

diff --git a/clang/test/CodeGenCXX/call-with-static-chain.cpp b/clang/test/CodeGenCXX/call-with-static-chain.cpp
new file mode 100644
index 00000000000..7cf929189f2
--- /dev/null
+++ b/clang/test/CodeGenCXX/call-with-static-chain.cpp
@@ -0,0 +1,39 @@
+// RUN: %clang_cc1 -triple i386-unknown-unknown -emit-llvm -o - %s | FileCheck -check-prefix=CHECK32 %s
+// RUN: %clang_cc1 -triple x86_64-unknown-unknown -emit-llvm -o - %s | FileCheck -check-prefix=CHECK64 %s
+
+struct A {
+  long x, y;
+};
+
+struct B {
+  long x, y, z, w;
+};
+
+extern "C" {
+
+int f1(A, A, A, A);
+B f2(void);
+_Complex float f3(void);
+A &f4();
+
+}
+
+void test() {
+  A a;
+
+  // CHECK32: call i32 bitcast (i32 (%struct.A*, %struct.A*, %struct.A*, %struct.A*)* @f1 to i32 (i8*, %struct.A*, %struct.A*, %struct.A*, %struct.A*)*)(i8* nest bitcast (i32 (%struct.A*, %struct.A*, %struct.A*, %struct.A*)* @f1 to i8*)
+  // CHECK64: call i32 bitcast (i32 (i64, i64, i64, i64, i64, i64, %struct.A*)* @f1 to i32 (i8*, i64, i64, i64, i64, i64, i64, %struct.A*)*)(i8* nest bitcast (i32 (i64, i64, i64, i64, i64, i64, %struct.A*)* @f1 to i8*)
+  __builtin_call_with_static_chain(f1(a, a, a, a), f1);
+
+  // CHECK32: call void bitcast (void (%struct.B*)* @f2 to void (%struct.B*, i8*)*)(%struct.B* sret %{{[0-9a-z]+}}, i8* nest bitcast (void (%struct.B*)* @f2 to i8*))
+  // CHECK64: call void bitcast (void (%struct.B*)* @f2 to void (%struct.B*, i8*)*)(%struct.B* sret %{{[0-9a-z]+}}, i8* nest bitcast (void (%struct.B*)* @f2 to i8*))
+  __builtin_call_with_static_chain(f2(), f2);
+
+  // CHECK32: call i64 bitcast (i64 ()* @f3 to i64 (i8*)*)(i8* nest bitcast (i64 ()* @f3 to i8*))
+  // CHECK64: call <2 x float> bitcast (<2 x float> ()* @f3 to <2 x float> (i8*)*)(i8* nest bitcast (<2 x float> ()* @f3 to i8*))
+  __builtin_call_with_static_chain(f3(), f3);
+
+  // CHECK32: call dereferenceable(8) %struct.A* bitcast (%struct.A* ()* @f4 to %struct.A* (i8*)*)(i8* nest bitcast (%struct.A* ()* @f4 to i8*))
+  // CHECK64: call dereferenceable(16) %struct.A* bitcast (%struct.A* ()* @f4 to %struct.A* (i8*)*)(i8* nest bitcast (%struct.A* ()* @f4 to i8*))
+  __builtin_call_with_static_chain(f4(), f4);
+}