================ @@ -0,0 +1,157 @@ +#===-----------------------------------------------------------------------===// +# +# Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. +# See https://llvm.org/LICENSE.txt for license information. +# SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception +# +#===----------------------------------------------------------------------===// +# +# This is a Nix recipe for collecting reproducers for benchmarking purposes in a +# reproducible way. It works by injecting a linker wrapper that embeds a +# reproducer tarball into a non-allocated section of every linked object, which +# generally causes them to be smuggled out of the build tree in a section of the +# final binaries. In principle, this technique should let us collect reproducers +# from any project packaged by Nix without project-specific knowledge, but as +# you can see below, many interesting ones need a few hacks. +# +# If you have Nix installed, you can build the reproducers with the following +# command: +# +# TMPDIR=/var/tmp nix-build -j6 --log-format bar collect.nix +# +# This will result in building several large projects including Chromium and +# Firefox, which will take some time, and it will also build most of the +# dependencies for non-native targets. Eventually you will get a result +# directory containing all the reproducers. +# +# The following projects have been tested successfully: +# - chrome (native only, cross builds fail building the qtbase dependency) +# - firefox (all targets) +# - linux-kernel (all targets, requires patched nixpkgs) +# - ladybird (native only, same problem as chromium) +# - llvm (all targets) + +{ + nixpkgsDir ? fetchTarball "https://github.com/NixOS/nixpkgs/archive/992f916556fcfaa94451ebc7fc6e396134bbf5b1.tar.gz";, + nixpkgs ? import nixpkgsDir, +}: +let + reproducerPkgs = + crossSystem: + let + pkgs = nixpkgs { inherit crossSystem; }; + # Wraps the given stdenv and lld package into a variant that collects + # the reproducer and builds with debug info. + reproducerCollectingStdenv = + stdenv: lld: + let + bintools = stdenv.cc.bintools.override { + extraBuildCommands = '' + wrap ${stdenv.cc.targetPrefix}nix-wrap-lld ${nixpkgsDir}/pkgs/build-support/bintools-wrapper/ld-wrapper.sh ${lld}/bin/ld.lld + export lz4=${pkgs.lib.getBin pkgs.buildPackages.lz4}/bin/lz4 + substituteAll ${./ld-wrapper.sh} $out/bin/${stdenv.cc.targetPrefix}ld + chmod +x $out/bin/${stdenv.cc.targetPrefix}ld + substituteAll ${./ld-wrapper.sh} $out/bin/${stdenv.cc.targetPrefix}ld.lld + chmod +x $out/bin/${stdenv.cc.targetPrefix}ld.lld + ''; + }; + in + pkgs.withCFlags [ "-g1" ] (stdenv.override (old: { + allowedRequisites = null; + cc = stdenv.cc.override { inherit bintools; }; + })); + withReproducerCollectingStdenv = pkg: pkg.override { + stdenv = reproducerCollectingStdenv pkgs.stdenv pkgs.buildPackages.lld; + }; + withReproducerCollectingClangStdenv = pkg: pkg.override { + clangStdenv = reproducerCollectingStdenv pkgs.clangStdenv pkgs.buildPackages.lld; + }; + in + { + # For benchmarking the linker we want to disable LTO as otherwise we would + # just be benchmarking the LLVM optimizer. Also, we generally want the + # package to use the regular stdenv in order to simplify wrapping it. + # Firefox normally uses the rustc stdenv but uses the regular one if + # LTO is disabled so we kill two birds with one stone by disabling it. + # Chromium uses the rustc stdenv unconditionally so we need the stuff + # below to make sure that it finds our wrapped stdenv. + chrome = + (pkgs.chromium.override { + newScope = + extra: + pkgs.newScope ( + extra + // { + pkgsBuildBuild = { + pkg-config = pkgs.pkgsBuildBuild.pkg-config; + rustc = { + llvmPackages = rec { + stdenv = reproducerCollectingStdenv pkgs.pkgsBuildBuild.rustc.llvmPackages.stdenv pkgs.pkgsBuildBuild.rustc.llvmPackages.lld; + bintools = stdenv.cc.bintools; + }; + }; + }; + } + ); + pkgs = { + rustc = { + llvmPackages = { + stdenv = reproducerCollectingStdenv pkgs.rustc.llvmPackages.stdenv pkgs.rustc.llvmPackages.lld; + }; + }; + }; + }).browser.overrideAttrs + (old: { + configurePhase = + old.configurePhase + + '' + echo use_thin_lto = false >> out/Release/args.gn + echo is_cfi = false >> out/Release/args.gn + ''; + }); + firefox = (withReproducerCollectingStdenv pkgs.firefox-unwrapped).override { + ltoSupport = false; + pgoSupport = false; + }; + # Won't work until https://github.com/NixOS/nixpkgs/pull/390631 lands. + # Can replace above line with + # nixpkgsDir ? fetchTarball "https://github.com/NixOS/nixpkgs/archive/fbc5923fb30c7e1957a729f19f22968083fb473f.tar.gz";, + # for testing with that PR. + linux-kernel = (withReproducerCollectingStdenv pkgs.linux_latest).dev; + ladybird = withReproducerCollectingStdenv pkgs.ladybird; + llvm = withReproducerCollectingStdenv pkgs.llvm; + webkitgtk = withReproducerCollectingClangStdenv pkgs.webkitgtk; + hello = withReproducerCollectingStdenv pkgs.hello; + }; + targets = { + x86_64 = reproducerPkgs { config = "x86_64-unknown-linux-gnu"; }; + aarch64 = reproducerPkgs { config = "aarch64-unknown-linux-gnu"; }; + riscv64 = reproducerPkgs { config = "riscv64-unknown-linux-gnu"; }; + }; + nativePkgs = nixpkgs { }; +in +derivation { ---------------- pcc wrote:
Mostly because I wasn't aware of it. Done https://github.com/llvm/llvm-project/pull/145789 _______________________________________________ llvm-branch-commits mailing list [email protected] https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-branch-commits
