Can't compile for OpenWRT

[Bigomby]

Hi, I'm trying to cross compile a Rust app for LEDE (fork of OpenWRT) but I'm stuck.

The application is just an hello_world example:

fn main() {
    println!("Hello, world");
}

These are the steps I performed:

1. In first place I downloaded the LEDE SDK and compiled successfully the image and the toolchain for my device (mips-openwrt-linux-musl-gcc).

2. Install the Rust std using rustup add mips-unknown-linux-musl.

3. Create a .cargo/config file in my project with the following content:

   [target.mips-unknown-linux-musl]
   linker = "mips-openwrt-linux-musl-gcc"
   

4. Build the app using cargo build --release --target=mips-unknown-linux-musl.

5. Deploy the executable to the device using scp.

6. Got Illegal instruction

On target

$ ldd hello_world
/lib/ld-musl-mips-sf.so.1 (0x558c2000)                                                 
libgcc_s.so.1 => /lib/libgcc_s.so.1 (0x77cc4000)                                       
libc.so => /lib/ld-musl-mips-sf.so.1 (0x558c2000)  

$ ldd --version
musl libc (mips-sf)
Version 1.1.15
Dynamic Program Loader
Usage: ldd [options] [--] pathname

On host

$ mips-openwrt-linux-musl-gcc -v
Reading specs from /opt/lede/staging_dir/toolchain-mips_mips32_gcc-5.4.0_musl-1.1.15/bin/../lib/gcc/mips-openwrt-linux-musl/5.4.0/specs
COLLECT_GCC=mips-openwrt-linux-musl-gcc
COLLECT_LTO_WRAPPER=/opt/lede/staging_dir/toolchain-mips_mips32_gcc-5.4.0_musl-1.1.15/bin/../libexec/gcc/mips-openwrt-linux-musl/5.4.0/lto-wrapper
Target: mips-openwrt-linux-musl
Configured with: /home/diego/source/build_dir/toolchain-mips_mips32_gcc-5.4.0_musl-1.1.15/gcc-5.4.0/configure --with-bugurl=http://www.lede-project.org/bugs/ --with-pkgversion='LEDE GCC 5.4.0 r2032' --prefix=/home/diego/source/staging_dir/toolchain-mips_mips32_gcc-5.4.0_musl-1.1.15 --build=x86_64-linux-gnu --host=x86_64-linux-gnu --target=mips-openwrt-linux-musl --with-gnu-ld --enable-target-optspace --disable-libgomp --disable-libmudflap --disable-multilib --disable-libmpx --disable-nls --without-isl --without-cloog --with-host-libstdcxx=-lstdc++ --with-float=soft --with-gmp=/home/diego/source/staging_dir/host --with-mpfr=/home/diego/source/staging_dir/host --with-mpc=/home/diego/source/staging_dir/host --disable-decimal-float --with-mips-plt --with-diagnostics-color=auto-if-env --disable-libssp --enable-__cxa_atexit --with-headers=/home/diego/source/staging_dir/toolchain-mips_mips32_gcc-5.4.0_musl-1.1.15/include --disable-libsanitizer --enable-languages=c,c++ --enable-shared --enable-threads --with-slibdir=/home/diego/source/staging_dir/toolchain-mips_mips32_gcc-5.4.0_musl-1.1.15/lib --enable-lto --with-libelf=/home/diego/source/staging_dir/host
Thread model: posix
gcc version 5.4.0 (LEDE GCC 5.4.0 r2032)

Disabling jemalloc

If I use rust nightly and disable jemalloc as following:

#![feature(alloc_system)]
extern crate alloc_system;

fn main() {
    println!("Hello, world");
}

Then it works! But as I keep adding code the application eventually crashes with another Illegal instruction. For example:

Works

TcpStream::connect("130.206.193.115:80").unwrap();

Does not work

TcpStream::connect("google.com:80").unwrap();'

I don't know what I'm doing wrong. Any help will be appreciated.

[japaric]

Hola, Diego

This seems like a bug in either the Rust compiler or in the infrastructure that
builds the binary releases of std for this target so I'm going to move this to
rust-lang/rust.