nixpkgs/pkgs/development/compilers/gcc/common/checksum.nix

41 lines
1.6 KiB
Nix

{ lib
, stdenv
, nukeReferences
, langC
, langCC
, runtimeShell
}:
let
enableChecksum = (with stdenv; buildPlatform == hostPlatform && hostPlatform == targetPlatform) && langC && langCC && !stdenv.hostPlatform.isDarwin;
in
(pkg: pkg.overrideAttrs (previousAttrs: lib.optionalAttrs enableChecksum {
outputs = previousAttrs.outputs ++ lib.optionals enableChecksum [ "checksum" ];
# This is a separate phase because gcc assembles its phase scripts
# in bash instead of nix (we should fix that).
preFixupPhases = (previousAttrs.preFixupPhases or []) ++ [ "postInstallSaveChecksumPhase" ];
#
# gcc uses an auxiliary utility `genchecksum` to md5-hash (most of) its
# `.o` and `.a` files prior to linking (in case the linker is
# nondeterministic). Since we want to compare across gccs built from two
# separate derivations, we wrap `genchecksum` with a `nuke-references`
# call. We also stash copies of the inputs to `genchecksum` in
# `$checksum/inputs/` -- this is extremely helpful for debugging since
# it's hard to get Nix to not delete the $NIX_BUILD_TOP of a successful
# build.
#
postInstallSaveChecksumPhase = ''
mv gcc/build/genchecksum gcc/build/.genchecksum-wrapped
cat > gcc/build/genchecksum <<\EOF
#!${runtimeShell}
${nukeReferences}/bin/nuke-refs $@
for INPUT in "$@"; do install -Dt $INPUT $checksum/inputs/; done
exec build/.genchecksum-wrapped $@
EOF
chmod +x gcc/build/genchecksum
rm gcc/*-checksum.*
make -C gcc cc1-checksum.o cc1plus-checksum.o
install -Dt $checksum/checksums/ gcc/cc*-checksum.o
'';
}))