HiGHS 無法與“未定義參考”錯誤鏈接

Question

在 Arch Linux x86_64 上，Rust 1.66.0 穩定，g++ 12.2.0。

我在鏈接good-lp crate 時遇到問題，並將其縮小到它的間接依賴highs-sys ，甚至在我自己的代碼之外。

這發生在最新主控 (c785240) 以及 v1.2.2 和 v0.2.1（我通過good-lp成功使用了幾個月）的干凈檢出上。 所以這不是highs-sys中的新問題，很可能是我的工具鏈的問題。

版本：

$ cargo --version
cargo 1.66.0 (d65d197ad 2022-11-15)
$ rustc --version
rustc 1.66.0 (69f9c33d7 2022-12-12)
$ cc --version
cc (GCC) 12.2.0
...
$ ld --version
GNU ld (GNU Binutils) 2.39.0
...

克隆和構建：

$ git clone --recursive https://github.com/rust-or/highs-sys
$ cd highs-sys
$ cargo build
...
    Finished dev [unoptimized + debuginfo] target(s) in 3m 35s
$ cargo test --lib
    Finished test [unoptimized + debuginfo] target(s) in 0.04s
     Running unittests src/lib.rs (target/debug/deps/highs_sys-96b0b941fcc31775)

running 2 tests
test bindgen_test_layout___fsid_t ... ok
test bindgen_test_layout_imaxdiv_t ... ok

test result: ok. 2 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out; finished in 0.00s

到目前為止一切都很好。 當我們嘗試使用生成的庫時會出現問題，即使它有自己的集成測試：

$ cargo test --test test_highs_call
   Compiling highs-sys v1.2.2 (/tmp/highs-sys)
error: linking with `cc` failed: exit status: 1
  |
  = note: "cc" "-m64" "/tmp/rustccbaKBt/symbols.o" "/tmp/highs-sys/target/debug/deps/test_highs_call-e669101ae4108d78.110gvlokoswtomfn.rcgu.o" "/tmp/highs-sys/target/debug/deps/test_highs_call-e669101ae4108d78.13y9v90q7e3dvfo2.rcgu.o" "/tmp/highs-sys/target/debug/deps/test_highs_call-e669101ae4108d78.17wo7aophf8in4vn.rcgu.o" "/tmp/highs-sys/target/debug/deps/test_highs_call-e669101ae4108d78.1cdkl7c2apbn7crn.rcgu.o" "/tmp/highs-sys/target/debug/deps/test_highs_call-e669101ae4108d78.1dj1sbwseam0n9ft.rcgu.o" "/tmp/highs-sys/target/debug/deps/test_highs_call-e669101ae4108d78.1hgigplg6qv30idz.rcgu.o" "/tmp/highs-sys/target/debug/deps/test_highs_call-e669101ae4108d78.1ms9q0du418ic26n.rcgu.o" "/tmp/highs-sys/target/debug/deps/test_highs_call-e669101ae4108d78.1tcgu3qw79kuuw1h.rcgu.o" "/tmp/highs-sys/target/debug/deps/test_highs_call-e669101ae4108d78.1vs3h8jyr2rojt51.rcgu.o" "/tmp/highs-sys/target/debug/deps/test_highs_call-e669101ae4108d78.20xdzk038hc30h4j.rcgu.o" "/tmp/highs-sys/target/debug/deps/test_highs_call-e669101ae4108d78.25ph4lcxn1xxn6fn.rcgu.o" "/tmp/highs-sys/target/debug/deps/test_highs_call-e669101ae4108d78.27am5w6h2agsxcl7.rcgu.o" "/tmp/highs-sys/target/debug/deps/test_highs_call-e669101ae4108d78.2djhnnv2jm2ibcl3.rcgu.o" "/tmp/highs-sys/target/debug/deps/test_highs_call-e669101ae4108d78.2i1j9l2lu5t0k0vu.rcgu.o" "/tmp/highs-sys/target/debug/deps/test_highs_call-e669101ae4108d78.2meo5gq21h6h8bqe.rcgu.o" "/tmp/highs-sys/target/debug/deps/test_highs_call-e669101ae4108d78.2ol9s57flfu167qp.rcgu.o" "/tmp/highs-sys/target/debug/deps/test_highs_call-e669101ae4108d78.2s2g91x597h8e2ey.rcgu.o" "/tmp/highs-sys/target/debug/deps/test_highs_call-e669101ae4108d78.2v1cfn4oct7skc3q.rcgu.o" "/tmp/highs-sys/target/debug/deps/test_highs_call-e669101ae4108d78.2v9apdn2isgwdl5q.rcgu.o" "/tmp/highs-sys/target/debug/deps/test_highs_call-e669101ae4108d78.2wpeqt6tzxghqi56.rcgu.o" "/tmp/highs-sys/target/debug/deps/test_highs_call-e669101ae4108d78.2yk7p7w6ixraj427.rcgu.o" "/tmp/highs-sys/target/debug/deps/test_highs_call-e669101ae4108d78.2z4b238c1zbjnij6.rcgu.o" "/tmp/highs-sys/target/debug/deps/test_highs_call-e669101ae4108d78.2zlr9mnhg9hyf02g.rcgu.o" "/tmp/highs-sys/target/debug/deps/test_highs_call-e669101ae4108d78.32cfoccwtdvhq06x.rcgu.o" "/tmp/highs-sys/target/debug/deps/test_highs_call-e669101ae4108d78.33nztruk7k2tts8x.rcgu.o" "/tmp/highs-sys/target/debug/deps/test_highs_call-e669101ae4108d78.3cvdzi91jork7mds.rcgu.o" "/tmp/highs-sys/target/debug/deps/test_highs_call-e669101ae4108d78.3fb9xf8nxxzcec41.rcgu.o" "/tmp/highs-sys/target/debug/deps/test_highs_call-e669101ae4108d78.3is6rgf4g5g16vl3.rcgu.o" "/tmp/highs-sys/target/debug/deps/test_highs_call-e669101ae4108d78.3s3dhxd64ny5tive.rcgu.o" "/tmp/highs-sys/target/debug/deps/test_highs_call-e669101ae4108d78.3wn5g0h8q5u3bxky.rcgu.o" "/tmp/highs-sys/target/debug/deps/test_highs_call-e669101ae4108d78.4150s6y93i5ma35t.rcgu.o" "/tmp/highs-sys/target/debug/deps/test_highs_call-e669101ae4108d78.4335j389sygn8m99.rcgu.o" "/tmp/highs-sys/target/debug/deps/test_highs_call-e669101ae4108d78.44i1r6id1s31acf1.rcgu.o" "/tmp/highs-sys/target/debug/deps/test_highs_call-e669101ae4108d78.4injouqsnun7hcvt.rcgu.o" "/tmp/highs-sys/target/debug/deps/test_highs_call-e669101ae4108d78.4nb66ozge3nmeuwq.rcgu.o" "/tmp/highs-sys/target/debug/deps/test_highs_call-e669101ae4108d78.4p2li2uv9dxcrx2d.rcgu.o" "/tmp/highs-sys/target/debug/deps/test_highs_call-e669101ae4108d78.4pz1m3mlzi8imskl.rcgu.o" "/tmp/highs-sys/target/debug/deps/test_highs_call-e669101ae4108d78.4tg55omun1u77yh3.rcgu.o" "/tmp/highs-sys/target/debug/deps/test_highs_call-e669101ae4108d78.4thto7zkdscqxses.rcgu.o" "/tmp/highs-sys/target/debug/deps/test_highs_call-e669101ae4108d78.4vrsyb4og25lcxo8.rcgu.o" "/tmp/highs-sys/target/debug/deps/test_highs_call-e669101ae4108d78.4z0e0rsh1apo67mr.rcgu.o" "/tmp/highs-sys/target/debug/deps/test_highs_call-e669101ae4108d78.50cxv68n1h5055a5.rcgu.o" "/tmp/highs-sys/target/debug/deps/test_highs_call-e669101ae4108d78.515xy9o2bj3al2ry.rcgu.o" "/tmp/highs-sys/target/debug/deps/test_highs_call-e669101ae4108d78.59no2g8u5zmbleot.rcgu.o" "/tmp/highs-sys/target/debug/deps/test_highs_call-e669101ae4108d78.5b574862nrupsals.rcgu.o" "/tmp/highs-sys/target/debug/deps/test_highs_call-e669101ae4108d78.5fu18wwg3p5nmrsh.rcgu.o" "/tmp/highs-sys/target/debug/deps/test_highs_call-e669101ae4108d78.5gi5ablibidmtrpd.rcgu.o" "/tmp/highs-sys/target/debug/deps/test_highs_call-e669101ae4108d78.kjht10drvblu37w.rcgu.o" "/tmp/highs-sys/target/debug/deps/test_highs_call-e669101ae4108d78.ugtef95uy6fok7q.rcgu.o" "/tmp/highs-sys/target/debug/deps/test_highs_call-e669101ae4108d78.xcjfvort5vhydtl.rcgu.o" "/tmp/highs-sys/target/debug/deps/test_highs_call-e669101ae4108d78.3mrzemp57wngq71t.rcgu.o" "-Wl,--as-needed" "-L" "/tmp/highs-sys/target/debug/deps" "-L" "/tmp/highs-sys/target/debug/build/highs-sys-21b14ce07e65289c/out/lib" "-L" "/home/thomas/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/rustlib/x86_64-unknown-linux-gnu/lib" "-Wl,-Bstatic" "/home/thomas/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/rustlib/x86_64-unknown-linux-gnu/lib/libtest-5678a62cd2e949f2.rlib" "/home/thomas/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/rustlib/x86_64-unknown-linux-gnu/lib/libgetopts-cafb712826ee2a26.rlib" "/home/thomas/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/rustlib/x86_64-unknown-linux-gnu/lib/libunicode_width-bb4ac1585c9c1153.rlib" "/home/thomas/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/rustlib/x86_64-unknown-linux-gnu/lib/librustc_std_workspace_std-69fab17bbe87f87e.rlib" "/tmp/highs-sys/target/debug/deps/libhighs_sys-addd17046a23d2a8.rlib" "/home/thomas/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/rustlib/x86_64-unknown-linux-gnu/lib/libstd-a11e3ca400b3ed09.rlib" "/home/thomas/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/rustlib/x86_64-unknown-linux-gnu/lib/libpanic_unwind-3e82a3fced649488.rlib" "/home/thomas/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/rustlib/x86_64-unknown-linux-gnu/lib/libobject-53a4330185981bcb.rlib" "/home/thomas/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/rustlib/x86_64-unknown-linux-gnu/lib/libmemchr-2a8b57667b4852b5.rlib" "/home/thomas/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/rustlib/x86_64-unknown-linux-gnu/lib/libaddr2line-9370462deca12c5a.rlib" "/home/thomas/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/rustlib/x86_64-unknown-linux-gnu/lib/libgimli-7da763b8d3620472.rlib" "/home/thomas/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/rustlib/x86_64-unknown-linux-gnu/lib/librustc_demangle-5bde27582a7f5af7.rlib" "/home/thomas/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/rustlib/x86_64-unknown-linux-gnu/lib/libstd_detect-1204e05b2d47e3d7.rlib" "/home/thomas/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/rustlib/x86_64-unknown-linux-gnu/lib/libcfg_if-43987de2766b6923.rlib" "/home/thomas/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/rustlib/x86_64-unknown-linux-gnu/lib/libhashbrown-d6499a0705316aa5.rlib" "/home/thomas/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/rustlib/x86_64-unknown-linux-gnu/lib/libminiz_oxide-c9a27c90d8fbf11e.rlib" "/home/thomas/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/rustlib/x86_64-unknown-linux-gnu/lib/libadler-8f159929cbfdfaf1.rlib" "/home/thomas/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/rustlib/x86_64-unknown-linux-gnu/lib/librustc_std_workspace_alloc-d2f1e8f3bb5cba95.rlib" "/home/thomas/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/rustlib/x86_64-unknown-linux-gnu/lib/libunwind-9862f486269f442f.rlib" "/home/thomas/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/rustlib/x86_64-unknown-linux-gnu/lib/libcfg_if-0434381f2f012ae2.rlib" "/home/thomas/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/rustlib/x86_64-unknown-linux-gnu/lib/liblibc-68549403a59fd02e.rlib" "/home/thomas/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/rustlib/x86_64-unknown-linux-gnu/lib/liballoc-4cefb2045f924a5b.rlib" "/home/thomas/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/rustlib/x86_64-unknown-linux-gnu/lib/librustc_std_workspace_core-272615fc4f10c50d.rlib" "/home/thomas/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/rustlib/x86_64-unknown-linux-gnu/lib/libcore-860619b93700e7eb.rlib" "/home/thomas/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/rustlib/x86_64-unknown-linux-gnu/lib/libcompiler_builtins-b73e5b4656934876.rlib" "-Wl,-Bdynamic" "-lstdc++" "-lgomp" "-lgcc_s" "-lutil" "-lrt" "-lpthread" "-lm" "-ldl" "-lc" "-Wl,--eh-frame-hdr" "-Wl,-znoexecstack" "-L" "/home/thomas/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/rustlib/x86_64-unknown-linux-gnu/lib" "-o" "/tmp/highs-sys/target/debug/deps/test_highs_call-e669101ae4108d78" "-Wl,--gc-sections" "-pie" "-Wl,-zrelro,-znow" "-nodefaultlibs"
  = note: /usr/bin/ld: /tmp/highs-sys/target/debug/deps/test_highs_call-e669101ae4108d78.5gi5ablibidmtrpd.rcgu.o: in function `test_highs_call::highs_call':
          /tmp/highs-sys/tests/test_highs_call.rs:88: undefined reference to `Highs_lpCall'
          collect2: error: ld returned 1 exit status
          
  = note: some `extern` functions couldn't be found; some native libraries may need to be installed or have their path specified
  = note: use the `-l` flag to specify native libraries to link
  = note: use the `cargo:rustc-link-lib` directive to specify the native libraries to link with Cargo (see https://doc.rust-lang.org/cargo/reference/build-scripts.html#cargorustc-link-libkindname)

error: could not compile `highs-sys` due to previous error

其他集成測試test_highs_functions類似的輸出，但未定義對該文件中使用的所有Highs_*函數的引用。

詳細的構建輸出：

$ cargo build --verbose --test test_highs_call
...
   Compiling highs-sys v1.2.2 (/tmp/highs-sys)
     Running `rustc --crate-name test_highs_call --edition=2018 tests/test_highs_call.rs --error-format=json --json=diagnostic-rendered-ansi,artifacts,future-incompat --emit=dep-info,link -C embed-bitcode=no -C debuginfo=2 --test -C metadata=e669101ae4108d78 -C extra-filename=-e669101ae4108d78 --out-dir /tmp/highs-sys/target/debug/deps -C incremental=/tmp/highs-sys/target/debug/incremental -L dependency=/tmp/highs-sys/target/debug/deps --extern highs_sys=/tmp/highs-sys/target/debug/deps/libhighs_sys-addd17046a23d2a8.rlib -L native=/tmp/highs-sys/target/debug/build/highs-sys-21b14ce07e65289c/out/lib`
...
... and then the above error again 

該rustc命令在手動運行時也會失敗並出現相同的錯誤。

由於/tmp/rustccbaKBt/symbols.o已被刪除，手動運行cc命令失敗，但如果我從命令行中刪除它，同樣的錯誤再次發生。

該符號在此文件中被稱為未定義 ( U )：

$ nm target/debug/deps/test_highs_call-e669101ae4108d78.5gi5ablibidmtrpd.rcgu.o | grep Highs_lpCall
                 U Highs_lpCall

它在這一個中被定義（ T ），稍后出現在命令行中，因為它應該：

$ nm /tmp/highs-sys/target/debug/deps/libhighs_sys-addd17046a23d2a8.rlib | grep Highs_lpCall
nm: lib.rmeta: no symbols
00000000 T Highs_lpCall

但是，所有符號都出現在地址00000000處，這在我不知情的人看來很可疑。

老實說，我不確定這是否是高點問題，但鏈接到 C API 的其他庫對我來說工作正常。

還嘗試使用 gcc11，它在存儲庫中仍作為單獨的包提供：

$ export CC=/usr/bin/gcc-11
$ export CXX=/usr/bin/g++-11
$ export RUSTFLAGS="-C linker=/usr/bin/gcc-11"

這使得它也因“未定義的引用”錯誤而出錯。 這很奇怪，因為我使用 GCC 11 已經有一段時間了。

但是當我將這些變量設置為使用 clang 而不是 gcc 時......

$ export CC=/usr/bin/clang
$ export CXX=/usr/bin/clang++
$ export RUSTFLAGS="-C link-arg=-fuse-ld=lld"

...然后它成功鏈接並且測試是綠色的。 但這不是一個合適的解決方案。

知道我還可以嘗試什么嗎？

Answer 1

事實證明這是由於鏈接時間優化 (LTO)。

libhighs.a是由 GCC 使用-flto -fno-fat-lto-objects從 C++ 代碼編譯而來，導致它只將 GCC 中間字節碼發送到存檔中，而不是實際的機器代碼。

但是由於在鏈接期間未啟用 LTO，因此在鏈接時也沒有生成機器代碼。 通常 GNU 鏈接器會處理這個問題，我仍然不清楚為什么它甚至在很好地詢問之后也沒有...但我不想將 GNU 鏈接器用於 Rust 代碼，因為那樣我會失去在 Rust 代碼（始終使用 LLVM 位碼）上使用 LTO 的選項。

所以目前，我認為最好的解決方案是在 C++ HiGHS 構建中禁用 LTO。 我向highs-sys提交了一個問題，並加入了 HiGHS的一個問題，以使 LTO 更具可選性。