Fix cargo test

Author: parasyte

src/lib.rs

@@ -1,6 +1,7 @@
 #![feature(global_asm)]
 #![feature(lang_items)]
 #![warn(rust_2018_idioms)]
+#![allow(unused_attributes)]
 #![no_std]
 
 mod math;
@@ -10,7 +11,8 @@ use core::panic::PanicInfo;
 pub use crate::platforms::*;
 
 /// This is the executable start function, which directly follows the entry point.
-#[lang = "start"]
+#[cfg_attr(not(test), lang = "start")]
+#[cfg(not(test))]
 extern "C" fn start<T>(user_main: fn() -> T, _argc: isize, _argv: *const *const u8) -> isize
 where
     T: Termination,
@@ -19,7 +21,7 @@ where
 }
 
 /// Termination trait required for the start function.
-#[lang = "termination"]
+#[cfg_attr(not(test), lang = "termination")]
 trait Termination {
     fn report(self) -> i32;
 }
@@ -32,7 +34,7 @@ impl Termination for () {
 }
 
 /// This function is called on panic.
-#[panic_handler]
+#[cfg_attr(not(test), panic_handler)]
 #[no_mangle]
 pub fn panic(_info: &PanicInfo<'_>) -> ! {
     loop {}