From: Jakub Jirutka Date: Sat, 08 Aug 2016 15:06:00 +0200 Subject: [PATCH] Fix linux_musl_base for native musl host See https://github.com/rust-lang/rust/pull/40113 --- a/src/librustc_back/target/linux_musl_base.rs +++ b/src/librustc_back/target/linux_musl_base.rs @@ -13,54 +13,14 @@ pub fn opts() -> TargetOptions { let mut base = super::linux_base::opts(); - // Make sure that the linker/gcc really don't pull in anything, including - // default objects, libs, etc. - base.pre_link_args.push("-nostdlib".to_string()); - // At least when this was tested, the linker would not add the // `GNU_EH_FRAME` program header to executables generated, which is required // when unwinding to locate the unwinding information. I'm not sure why this // argument is *not* necessary for normal builds, but it can't hurt! base.pre_link_args.push("-Wl,--eh-frame-hdr".to_string()); - // There's a whole bunch of circular dependencies when dealing with MUSL - // unfortunately. To put this in perspective libc is statically linked to - // liblibc and libunwind is statically linked to libstd: - // - // * libcore depends on `fmod` which is in libc (transitively in liblibc). - // liblibc, however, depends on libcore. - // * compiler-rt has personality symbols that depend on libunwind, but - // libunwind is in libstd which depends on compiler-rt. - // - // Recall that linkers discard libraries and object files as much as - // possible, and with all the static linking and archives flying around with - // MUSL the linker is super aggressively stripping out objects. For example - // the first case has fmod stripped from liblibc (it's in its own object - // file) so it's not there when libcore needs it. In the second example all - // the unused symbols from libunwind are stripped (each is in its own object - // file in libstd) before we end up linking compiler-rt which depends on - // those symbols. - // - // To deal with these circular dependencies we just force the compiler to - // link everything as a group, not stripping anything out until everything - // is processed. The linker will still perform a pass to strip out object - // files but it won't do so until all objects/archives have been processed. - base.pre_link_args.push("-Wl,-(".to_string()); - base.post_link_args.push("-Wl,-)".to_string()); - - // When generating a statically linked executable there's generally some - // small setup needed which is listed in these files. These are provided by - // a musl toolchain and are linked by default by the `musl-gcc` script. Note - // that `gcc` also does this by default, it just uses some different files. - // - // Each target directory for musl has these object files included in it so - // they'll be included from there. - base.pre_link_objects_exe.push("crt1.o".to_string()); - base.pre_link_objects_exe.push("crti.o".to_string()); - base.post_link_objects.push("crtn.o".to_string()); - // Except for on MIPS, these targets statically link libc by default. base.crt_static_default = true; base }