a7caaae9fb
Strip unexpected debuginfo from `libLLVM.so` and `librustc_driver.so` when not requesting any debuginfo As seen in #114175 and in [this zulip discussion](https://rust-lang.zulipchat.com/#narrow/stream/247081-t-compiler.2Fperformance/topic/Artifact.20sizes/near/379302655), there's still some small amount of debuginfo in LLVM's shared library on linux, even when not requesting it (nightly CI), coming from `libstdc++`. ``` $ readelf --debug-dump=info ~/.rustup/toolchains/nightly-x86_64-unknown-linux-gnu/lib/libLLVM-16-rust-1.73.0-nightly.so | grep DW_TAG_compile_unit -A5 | grep DW_AT_comp_dir | cut -d ":" -f 2- | counts 101 counts ( 1) 39 (38.6%, 38.6%): (indirect string, offset: 0x7): /tmp/gcc-build/x86_64-pc-linux-gnu/libstdc++-v3/libsupc++ ( 2) 38 (37.6%, 76.2%): (indirect string, offset: 0x43fb2): /tmp/gcc-build/x86_64-pc-linux-gnu/libstdc++-v3/src/c++11 ( 3) 23 (22.8%, 99.0%): (indirect string, offset: 0x18ed8): /tmp/gcc-build/x86_64-pc-linux-gnu/libstdc++-v3/src/c++98 ( 4) 1 ( 1.0%,100.0%): (indirect string, offset: 0x53f04): /tmp/gcc-build/x86_64-pc-linux-gnu/libstdc++-v3/src ``` Similarly, here's `librustc_driver.so` when not requesting debuginfo from either rustc or the tools (nightly CI), coming e.g. from our LLVM wrapper: ``` $ readelf --debug-dump=info ~/.rustup/toolchains/nightly-x86_64-unknown-linux-gnu/lib/librustc_driver-e534b3a316089f5f.so | grep DW_TAG_compile_unit -A5 | grep DW_AT_comp_dir | cut -d ":" -f 2- | counts 116 counts ( 1) 34 (29.3%, 29.3%): (indirect string, offset: 0x3c11): /tmp/gcc-build/x86_64-pc-linux-gnu/libstdc++-v3/libsupc++ ( 2) 32 (27.6%, 56.9%): (indirect string, offset: 0x9753c): /tmp/gcc-build/x86_64-pc-linux-gnu/libstdc++-v3/src/c++11 ( 3) 25 (21.6%, 78.4%): (indirect string, offset: 0x393bd): /tmp/gcc-build/x86_64-pc-linux-gnu/libstdc++-v3/src/c++98 ( 4) 23 (19.8%, 98.3%): (indirect string, offset: 0x33ed3): /cargo/registry/src/index.crates.io-6f17d22bba15001f/compiler_builtins-0.1.98 ( 5) 1 ( 0.9%, 99.1%): (indirect string, offset: 0xaffff): /rustc/0d95f9132909ae7c5f2456748d0ffd1c3ba4a8e8 ( 6) 1 ( 0.9%,100.0%): (indirect string, offset: 0xb604a): /tmp/gcc-build/x86_64-pc-linux-gnu/libstdc++-v3/src ``` To reduce the size of distributed artifacts, this PR strips debuginfo from the LLVM and `rustc_driver` shared libraries, when: - no debuginfo is requested when building LLVM: `link-shared` is true, `optimize` is true and `release-debuginfo` is false - no debuginfo is requested when building the rustc driver: - `debuginfo-level-rustc` and `debuginfo-level-tools` are off. - when building with a stage != 0 compiler: since this is about the distributed artifacts, there's no need to do this at other stages. - for both: on a x64 linux host and target where `strip -g` is available and fixes the issue (I don't know how to strip debuginfo from a `.dylib` on mac). The LLVM BOLTed .so, and `librustc_driver.so` are big there, and this will help a little. Other targets/hosts can be added in the future if we want to. #114175 did the same thing unconditionally in `opt-dist`, prior to BOLTing LLVM. But this should only be used in conjunction with the other config options mentioned above, and which `opt-dist` doesn't know about. Therefore, it makes more sense as in bootstrap when building LLVM and rustc when applicable and no debuginfo is requested. This shouldn't interact badly with CI caching builds and artifacts, right? --- From the other PR, `libLLVM-16-rust-1.73.0-nightly.so` prior to #114141: - master: 173.13 MiB - stripped debuginfo: 165.12 MiB (-8 MiB, -4.6%) `libLLVM-16-rust-1.73.0-nightly.so` after #114141: - master: 121.13 MiB - stripped debuginfo: 113.12 MiB (still -8 MiB, -6.6%) `librustc_driver.so`: - master: 118.58 MiB - stripped debuginfo: 106.46 MiB (-12 MiB, -10.2%) (Results are also available in this most recent [perf run's artifact sizes](https://perf.rust-lang.org/compare.html?start=b321edd1b2d4bd00c7b4611e8f20a03ee7b77023&end=810ab570d5d27facb91806e5d9847815d9dac22a&stat=instructions%3Au&tab=artifact-size)) |
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| .. | ||
| bootstrap | ||
| ci | ||
| doc | ||
| etc | ||
| librustdoc | ||
| llvm-project@a7d11c4537 | ||
| rustdoc-json-types | ||
| tools | ||
| README.md | ||
| stage0.json | ||
| version | ||
This directory contains some source code for the Rust project, including:
- The bootstrapping build system
- Various submodules for tools, like cargo, tidy, etc.
For more information on how various parts of the compiler work, see the rustc dev guide.