Undefined symbols when linking i686-unknown-uefi without using -Zbuild-std #104326
Description
Simple repro:
# rust_toolchain.toml [toolchain] channel = "nightly" targets = ["i686-unknown-uefi"]// src/main.rs: #![no_main] #![no_std] #[panic_handler] fn panic_handler(_info: &core::panic::PanicInfo) -> ! { loop {} } #[export_name = "efi_main"] pub extern "C" fn main(_h: *mut core::ffi::c_void, _st: *mut core::ffi::c_void) -> usize { panic!(); }Compile with cargo build --target i686-unknown-uefi. This fails with undefined symbols ___udivdi3 and ___umoddi3.
Full output
Compiling tmp-i686-test v0.1.0 (/var/home/nbishop/src/tmp-i686-test) error: linking with `rust-lld` failed: exit status: 1 | = note: "rust-lld" "-flavor" "link" "/NOLOGO" "/entry:efi_main" "/subsystem:efi_application" "/tmp/rustcf3Esr7/symbols.o" "/var/home/nbishop/src/tmp-i686-test/target/i686-unknown-uefi/debug/deps/tmp_i686_test-e070b2b3d9570a0b.4r7w5v2t9imd2qsu.rcgu.o" "/LIBPATH:/var/home/nbishop/src/tmp-i686-test/target/i686-unknown-uefi/debug/deps" "/LIBPATH:/var/home/nbishop/src/tmp-i686-test/target/debug/deps" "/LIBPATH:/var/home/nbishop/.rustup/toolchains/nightly-x86_64-unknown-linux-gnu/lib/rustlib/i686-unknown-uefi/lib" "/var/home/nbishop/.rustup/toolchains/nightly-x86_64-unknown-linux-gnu/lib/rustlib/i686-unknown-uefi/lib/librustc_std_workspace_core-87aa5ecf680885c4.rlib" "/var/home/nbishop/.rustup/toolchains/nightly-x86_64-unknown-linux-gnu/lib/rustlib/i686-unknown-uefi/lib/libcore-078ea958aaba8579.rlib" "/var/home/nbishop/.rustup/toolchains/nightly-x86_64-unknown-linux-gnu/lib/rustlib/i686-unknown-uefi/lib/libcompiler_builtins-a6f227741d962a9d.rlib" "/NXCOMPAT" "/LIBPATH:/var/home/nbishop/.rustup/toolchains/nightly-x86_64-unknown-linux-gnu/lib/rustlib/i686-unknown-uefi/lib" "/OUT:/var/home/nbishop/src/tmp-i686-test/target/i686-unknown-uefi/debug/deps/tmp_i686_test-e070b2b3d9570a0b.efi" "/OPT:REF,NOICF" "/DEBUG" "/NODEFAULTLIB" = note: rust-lld: error: undefined symbol: ___udivdi3 >>> referenced by /rustc/e75aab045fc476f176a58c408f6b06f0e275c6e1/library/core/src/num/dec2flt/decimal.rs:126 >>> libcore-078ea958aaba8579.rlib(core-078ea958aaba8579.core.3b584330-cgu.0.rcgu.o):(core::num::dec2flt::decimal::Decimal::left_shift::hdaf1b75087ea64fb) >>> referenced by /rustc/e75aab045fc476f176a58c408f6b06f0e275c6e1/library/core/src/num/dec2flt/decimal.rs:137 >>> libcore-078ea958aaba8579.rlib(core-078ea958aaba8579.core.3b584330-cgu.0.rcgu.o):(core::num::dec2flt::decimal::Decimal::left_shift::hdaf1b75087ea64fb) >>> referenced by /rustc/e75aab045fc476f176a58c408f6b06f0e275c6e1/library/core/src/num/flt2dec/strategy/dragon.rs:295 >>> libcore-078ea958aaba8579.rlib(core-078ea958aaba8579.core.3b584330-cgu.0.rcgu.o):(core::num::flt2dec::strategy::dragon::format_exact::h6e53ee3200af73e2) >>> referenced 40 more times rust-lld: error: undefined symbol: ___umoddi3 >>> referenced by /rustc/e75aab045fc476f176a58c408f6b06f0e275c6e1/library/core/src/fmt/num.rs:501 >>> libcore-078ea958aaba8579.rlib(core-078ea958aaba8579.core.3b584330-cgu.0.rcgu.o):(core::fmt::num::parse_u64_into::h6ca2586fb1d1d6c4) >>> referenced by /rustc/e75aab045fc476f176a58c408f6b06f0e275c6e1/library/core/src/fmt/num.rs:502 >>> libcore-078ea958aaba8579.rlib(core-078ea958aaba8579.core.3b584330-cgu.0.rcgu.o):(core::fmt::num::parse_u64_into::h6ca2586fb1d1d6c4) >>> referenced by /rustc/e75aab045fc476f176a58c408f6b06f0e275c6e1/library/core/src/fmt/num.rs:503 >>> libcore-078ea958aaba8579.rlib(core-078ea958aaba8579.core.3b584330-cgu.0.rcgu.o):(core::fmt::num::parse_u64_into::h6ca2586fb1d1d6c4) >>> referenced 2 more times Interestingly, the error does not reproduce when using -Zbuild-std. Compiling with cargo build --target i686-unknown-uefi -Zbuild-std=core,compiler_builtins is successful.
Meta
rustc --version --verbose:
rustc 1.67.0-nightly (e75aab045 2022-11-09) binary: rustc commit-hash: e75aab045fc476f176a58c408f6b06f0e275c6e1 commit-date: 2022-11-09 host: x86_64-unknown-linux-gnu release: 1.67.0-nightly LLVM version: 15.0.4