Add tests for compiling assembly

gcc-test/build.rs

@@ -14,4 +14,12 @@ fn main() {
                 .file("src/bar1.c")
                 .file("src/bar2.c")
                 .compile("libbar.a");
+
+    let target = std::env::var("TARGET").unwrap();
+    let file = target.split("-").next().unwrap();
+    let file = format!("src/{}.{}", file,
+                       if target.contains("msvc") {"asm"} else {"S"});
+    gcc::Config::new()
+                .file(file)
+                .compile("libasm.a");
 }

gcc-test/src/i686.S

@@ -0,0 +1,9 @@
+.globl asm
+asm:
+    mov $7, %eax
+    ret
+
+.globl _asm
+_asm:
+    mov $7, %eax
+    ret

gcc-test/src/lib.rs

@@ -1,8 +1,8 @@
 extern {
     pub fn foo() -> i32;
-}
 
-extern {
     pub fn bar1() -> i32;
     pub fn bar2() -> i32;
+
+    pub fn asm() -> i32;
 }

gcc-test/src/x86_64.S

@@ -0,0 +1,9 @@
+.globl asm
+asm:
+    mov $7, %eax
+    ret
+
+.globl _asm
+_asm:
+    mov $7, %eax
+    ret

gcc-test/src/x86_64.asm

@@ -0,0 +1,8 @@
+_TEXT SEGMENT
+
+asm PROC
+  MOV EAX, 7
+  RET
+asm ENDP
+
+END

gcc-test/tests/all.rs

@@ -17,3 +17,10 @@ fn bar_here() {
     }
 }
 
+
+#[test]
+fn asm_here() {
+    unsafe {
+        assert_eq!(asm(), 7);
+    }
+}