mulodi4 debug assertion

[japaric]

STR

#![feature(compiler_builtins_lib)]

extern crate compiler_builtins;

use compiler_builtins::int::mul::__mulodi4;

fn main() {
    let (a, b) = (72113192, -480093263);
    let mut overflow = 2;
    let c = __mulodi4(a, b, &mut overflow);
}

$ cross run --target armv7-unknown-linux-gnueabihf
     Running `/target/armv7-unknown-linux-gnueabihf/debug/foo`
thread 'main' panicked at 'attempt to subtract with overflow', /cargo/git/checkouts/compiler-builtins-ec094dc45a0179c8/0507842/src/int/sdiv.rs:13
note: Run with `RUST_BACKTRACE=1` for a backtrace.

The command hangs and doesn't return but that could be a Cross bug ... I don't know.

[japaric]

The problem actually originates from:

__divdi3(-9223372036854775808, -480093263)

[oli-obk]

can you publish a new snapshot that includes this fix?

[japaric]

@oli-obk that snapshot crate was a hack. The compiler-builtins crate truly belongs in the sysroot; it's just that the rust-lang/rust version of that crate has too few intrinsics so I decided to directly depend on this crate (because I didn't want to use the C implementations of the intrinsics).

Xargo has been capable of putting custom crates in the sysroot for a while and this crate is now "thumb friendly" due to recent changes. I suggest that you remove the direct dependency to compiler-builtins from your dependency graph and instead build it as part of the Xargo sysroot. Example

If you want to continue using the snapshot crate, I'd be happy to transfer ownership of it to you so you can update / maintain it.