add codegen tests for 4 interesting platforms

Author: folkertdev

tests/codegen/naked-fn/naked-functions.rs

@@ -0,0 +1,131 @@
+//@ revisions: linux windows macos thumb
+//
+//@[linux] compile-flags: --target x86_64-unknown-linux-gnu
+//@[linux] needs-llvm-components: x86
+//@[windows] compile-flags: --target x86_64-pc-windows-gnu
+//@[windows] needs-llvm-components: x86
+//@[macos] compile-flags: --target aarch64-apple-darwin
+//@[macos] needs-llvm-components: arm
+//@[thumb] compile-flags: --target thumbv7em-none-eabi
+//@[thumb] needs-llvm-components: arm
+
+#![crate_type = "lib"]
+#![feature(no_core, lang_items, rustc_attrs, naked_functions)]
+#![no_core]
+
+#[rustc_builtin_macro]
+macro_rules! asm {
+    () => {};
+}
+
+#[lang = "sized"]
+trait Sized {}
+#[lang = "copy"]
+trait Copy {}
+
+// linux,windows: .intel_syntax
+//
+// linux:   .pushsection .text.naked_empty,\22ax\22, @progbits
+// macos:   .pushsection __TEXT,__text,regular,pure_instructions
+// windows: .pushsection .text.naked_empty,\22xr\22
+// thumb:   .pushsection .text.naked_empty,\22ax\22, %progbits
+//
+// CHECK: .balign 4
+//
+// linux,windows,thumb: .globl naked_empty
+// macos: .globl _naked_empty
+//
+// CHECK-NOT: .private_extern
+// CHECK-NOT: .hidden
+//
+// linux: .type naked_empty, @function
+//
+// windows: .def naked_empty
+// windows: .scl 2
+// windows: .type 32
+// windows: .endef naked_empty
+//
+// thumb: .type naked_empty, %function
+// thumb: .thumb
+// thumb: .thumb_func
+//
+// CHECK-LABEL: naked_empty:
+//
+// linux,macos,windows: ret
+// thumb: bx lr
+//
+// CHECK: .popsection
+//
+// thumb: .thumb
+//
+// linux,windows: .att_syntax
+
+#[no_mangle]
+#[naked]
+pub unsafe extern "C" fn naked_empty() {
+    #[cfg(not(all(target_arch = "arm", target_feature = "thumb-mode")))]
+    asm!("ret", options(noreturn));
+
+    #[cfg(all(target_arch = "arm", target_feature = "thumb-mode"))]
+    asm!("bx lr", options(noreturn));
+}
+
+// linux,windows: .intel_syntax
+//
+// linux:   .pushsection .text.naked_with_args_and_return,\22ax\22, @progbits
+// macos:   .pushsection __TEXT,__text,regular,pure_instructions
+// windows: .pushsection .text.naked_with_args_and_return,\22xr\22
+// thumb:   .pushsection .text.naked_with_args_and_return,\22ax\22, %progbits
+//
+// CHECK: .balign 4
+//
+// linux,windows,thumb: .globl naked_with_args_and_return
+// macos: .globl _naked_with_args_and_return
+//
+// CHECK-NOT: .private_extern
+// CHECK-NOT: .hidden
+//
+// linux: .type naked_with_args_and_return, @function
+//
+// windows: .def naked_with_args_and_return
+// windows: .scl 2
+// windows: .type 32
+// windows: .endef naked_with_args_and_return
+//
+// thumb: .type naked_with_args_and_return, %function
+// thumb: .thumb
+// thumb: .thumb_func
+//
+// CHECK-LABEL: naked_with_args_and_return:
+//
+// linux, windows: lea rax, [rdi + rsi]
+// macos: add x0, x0, x1
+// thumb: adds r0, r0, r1
+//
+// linux,macos,windows: ret
+// thumb: bx lr
+//
+// CHECK: .popsection
+//
+// thumb: .thumb
+//
+// linux,windows: .att_syntax
+
+#[no_mangle]
+#[naked]
+pub unsafe extern "C" fn naked_with_args_and_return(a: isize, b: isize) -> isize {
+    #[cfg(any(target_os = "windows", target_os = "linux"))]
+    {
+        asm!("lea rax, [rdi + rsi]", "ret", options(noreturn))
+    }
+
+    #[cfg(target_os = "macos")]
+    {
+        asm!("add x0, x0, x1", "ret", options(noreturn))
+    }
+
+    #[cfg(all(target_arch = "arm", target_feature = "thumb-mode"))]
+    {
+        asm!("adds r0, r0, r1", "bx lr", options(noreturn))
+    }
+}