Library ordering issue when linking against C ABI libraries with rustc

[kukrimate]

This was first reported in Debian at: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1059223
Then also reported in Ubuntu at: https://bugs.launchpad.net/ubuntu/+source/meson/+bug/2049904

When linking together a Rust program with a C static library, Meson produces the following command line:

rustc -C linker=cc --color=always -C debug-assertions=yes -C overflow-checks=no --crate-type bin -g --crate-name prog --emit dep-info=prog.d --emit link=prog --out-dir prog.p -C metadata=prog@exe -Clink-arg=libc_accessing_zlib.a -Clink-arg=-lz -L. ../prog.rs

Which ultimately ends up as rustc executing the following link command:

LC_ALL="C" PATH="/usr/lib/rustlib/aarch64-unknown-linux-gnu/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games:/snap/bin" VSLANG="1033" "cc" "/tmp/rustcqxuAcC/symbols.o" "prog.p/prog.prog.3a9e8efe5d7989d1-cgu.0.rcgu.o" "prog.p/prog.2valzr4aprd78wdd.rcgu.o" "-Wl,--as-needed" "-L" "." "-L" "/usr/lib/rustlib/aarch64-unknown-linux-gnu/lib" "-Wl,-Bstatic" "/usr/lib/rustlib/aarch64-unknown-linux-gnu/lib/libstd-3f505df5bf7b6973.rlib" "/usr/lib/rustlib/aarch64-unknown-linux-gnu/lib/libpanic_unwind-f7bbfb2a4f0106ba.rlib" "/usr/lib/rustlib/aarch64-unknown-linux-gnu/lib/libobject-799d4aa6228550fd.rlib" "/usr/lib/rustlib/aarch64-unknown-linux-gnu/lib/libmemchr-817c1781430e6007.rlib" "/usr/lib/rustlib/aarch64-unknown-linux-gnu/lib/libaddr2line-ad8936af23d8ece8.rlib" "/usr/lib/rustlib/aarch64-unknown-linux-gnu/lib/libgimli-fa9ccab1157705c6.rlib" "/usr/lib/rustlib/aarch64-unknown-linux-gnu/lib/librustc_demangle-0f0344f8af442a24.rlib" "/usr/lib/rustlib/aarch64-unknown-linux-gnu/lib/libstd_detect-f1d03073262366fd.rlib" "/usr/lib/rustlib/aarch64-unknown-linux-gnu/lib/libhashbrown-d2b728fe429f73fd.rlib" "/usr/lib/rustlib/aarch64-unknown-linux-gnu/lib/librustc_std_workspace_alloc-78f4eeade0e7b3f3.rlib" "/usr/lib/rustlib/aarch64-unknown-linux-gnu/lib/libminiz_oxide-386abc7d4431b549.rlib" "/usr/lib/rustlib/aarch64-unknown-linux-gnu/lib/libadler-f2fbe97df215d47a.rlib" "/usr/lib/rustlib/aarch64-unknown-linux-gnu/lib/libunwind-1b9c021e2652ca95.rlib" "/usr/lib/rustlib/aarch64-unknown-linux-gnu/lib/libcfg_if-a31e7b8703ef1917.rlib" "/usr/lib/rustlib/aarch64-unknown-linux-gnu/lib/liblibc-67315dfc1c311b62.rlib" "/usr/lib/rustlib/aarch64-unknown-linux-gnu/lib/liballoc-6f13ad92e9ef28f1.rlib" "/usr/lib/rustlib/aarch64-unknown-linux-gnu/lib/librustc_std_workspace_core-4647df6db5bfc191.rlib" "/usr/lib/rustlib/aarch64-unknown-linux-gnu/lib/libcore-7ca28360f44e13c1.rlib" "/usr/lib/rustlib/aarch64-unknown-linux-gnu/lib/libcompiler_builtins-bda26fded9d4fbc7.rlib" "-Wl,-Bdynamic" "-lgcc_s" "-lutil" "-lrt" "-lpthread" "-lm" "-ldl" "-lc" "-Wl,--eh-frame-hdr" "-Wl,-z,noexecstack" "-L" "/usr/lib/rustlib/aarch64-unknown-linux-gnu/lib" "-o" "prog" "-Wl,--gc-sections" "-pie" "-Wl,-z,relro,-z,now" "-nodefaultlibs" "libc_accessing_zlib.a" "-lz"

Unfortunately this is not correct, and can (and does on arm64 Ubuntu) result in undefined symbol errors in the C ABI static library, which is dependent on libc, but is specified after libc on the link command line.

Some previously proposed solutions are:

1. rustc to always link with libc last. I feel that this is inelegant due to specified external libraries not necessarily always requiring libc.
2. Meson to emit -Clink-arg=-lc explicitly on the rustc command line when linking against C ABI libraries. This is the patch I have proposed for Ubuntu.

[kukrimate]

@liushuyu

[xclaesse]

I think we could use -C default-linker-libraries: rust-lang/rust#54675