Fix linking issues with lang items

src/crt0/src/lib.rs

@@ -2,6 +2,7 @@
 
 #![no_std]
 #![feature(asm)]
+#![feature(linkage)]
 #![feature(naked_functions)]
 #![feature(panic_implementation)]
 
@@ -60,8 +61,9 @@ pub unsafe extern "C" fn _start_rust(sp: &'static Stack) -> ! {
 }
 
 #[panic_implementation]
+#[linkage = "weak"]
 #[no_mangle]
-pub extern "C" fn _start_panic(pi: &::core::panic::PanicInfo) -> ! {
+pub extern "C" fn rust_begin_unwind(pi: &::core::panic::PanicInfo) -> ! {
     use core::fmt::Write;
 
     let mut w = platform::FileWriter(2);

src/lib.rs

@@ -1,5 +1,6 @@
 #![no_std]
 #![feature(lang_items)]
+#![feature(linkage)]
 #![feature(panic_implementation)]
 
 //extern crate compiler_builtins;
@@ -28,9 +29,11 @@ pub extern crate time;
 pub extern crate unistd;
 pub extern crate wctype;
 
+#[cfg(not(test))]
 #[panic_implementation]
+#[linkage = "weak"]
 #[no_mangle]
-pub extern "C" fn relibc_panic(pi: &::core::panic::PanicInfo) -> ! {
+pub extern "C" fn rust_begin_unwind(pi: &::core::panic::PanicInfo) -> ! {
     use core::fmt::Write;
 
     let mut w = platform::FileWriter(2);
@@ -39,9 +42,17 @@ pub extern "C" fn relibc_panic(pi: &::core::panic::PanicInfo) -> ! {
     platform::exit(1);
 }
 
-#[lang = "oom"]
+#[cfg(not(test))]
+#[lang = "eh_personality"]
 #[no_mangle]
-pub extern fn relibc_oom(layout: ::core::alloc::Layout) -> ! {
+#[linkage = "weak"]
+pub extern "C" fn rust_eh_personality() {}
+
+#[cfg(not(test))]
+#[lang = "oom"]
+#[linkage = "weak"]
+#[no_mangle]
+pub extern fn rust_oom(layout: ::core::alloc::Layout) -> ! {
     use core::fmt::Write;
 
     let mut w = platform::FileWriter(2);
@@ -49,3 +60,16 @@ pub extern fn relibc_oom(layout: ::core::alloc::Layout) -> ! {
 
     platform::exit(1);
 }
+
+#[cfg(not(test))]
+#[allow(non_snake_case)]
+#[linkage = "weak"]
+#[no_mangle]
+pub extern "C" fn _Unwind_Resume() -> ! {
+    use core::fmt::Write;
+
+    let mut w = platform::FileWriter(2);
+    let _ = w.write_str("_Unwind_Resume\n");
+
+    platform::exit(1);
+}