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|
{ lib
, stdenv
, version
, langC
, langCC
, langJit
, enableShared
, targetPlatform
, hostPlatform
, withoutTargetLibc
, libcCross
}:
assert !stdenv.targetPlatform.hasSharedLibraries -> !enableShared;
drv: lib.pipe drv
([
(pkg: pkg.overrideAttrs (previousAttrs:
lib.optionalAttrs (
targetPlatform != hostPlatform &&
(enableShared || targetPlatform.isMinGW) &&
withoutTargetLibc
) {
makeFlags = [ "all-gcc" "all-target-libgcc" ];
installTargets = "install-gcc install-target-libgcc";
}))
] ++
# nixpkgs did not add the "libgcc" output until gcc11. In theory
# the following condition can be changed to `true`, but that has not
# been tested.
lib.optionals (lib.versionAtLeast version "11.0")
(let
targetPlatformSlash =
if hostPlatform.config == targetPlatform.config
then ""
else "${targetPlatform.config}/";
# If we are building a cross-compiler and the target libc provided
# to us at build time has a libgcc, use that instead of building a
# new one. This avoids having two separate (but identical) libgcc
# outpaths in the closure of most packages, which can be confusing.
useLibgccFromTargetLibc =
libcCross != null &&
libcCross?passthru.libgcc;
enableLibGccOutput =
(!stdenv.targetPlatform.isWindows || (with stdenv; targetPlatform == hostPlatform)) &&
!langJit &&
!stdenv.hostPlatform.isDarwin &&
enableShared &&
!useLibgccFromTargetLibc
;
# For some reason libgcc_s.so has major-version "2" on m68k but
# "1" everywhere else. Might be worth changing this to "*".
libgcc_s-version-major =
if targetPlatform.isM68k
then "2"
else "1";
in
[
(pkg: pkg.overrideAttrs (previousAttrs: lib.optionalAttrs useLibgccFromTargetLibc {
passthru = (previousAttrs.passthru or {}) // {
inherit (libcCross) libgcc;
};
}))
(pkg: pkg.overrideAttrs (previousAttrs: lib.optionalAttrs ((!langC) || langJit || enableLibGccOutput) {
outputs = previousAttrs.outputs ++ lib.optionals enableLibGccOutput [ "libgcc" ];
# This is a separate phase because gcc assembles its phase scripts
# in bash instead of nix (we should fix that).
preFixupPhases = (previousAttrs.preFixupPhases or []) ++ lib.optionals ((!langC) || enableLibGccOutput) [ "preFixupLibGccPhase" ];
preFixupLibGccPhase =
# delete extra/unused builds of libgcc_s in non-langC builds
# (i.e. libgccjit, gnat, etc) to avoid potential confusion
lib.optionalString (!langC) ''
rm -f $out/lib/libgcc_s.so*
''
+ lib.optionalString (hostPlatform.config != targetPlatform.config) ''
mkdir -p $lib/lib/
ln -s ${targetPlatformSlash}lib $lib/lib
''
# TODO(amjoseph): remove the `libgcc_s.so` symlinks below and replace them
# with a `-L${gccForLibs.libgcc}/lib` in cc-wrapper's
# `$out/nix-support/cc-flags`. See also:
# - https://github.com/NixOS/nixpkgs/pull/209870#discussion_r1130614895
# - https://github.com/NixOS/nixpkgs/pull/209870#discussion_r1130635982
# - https://github.com/NixOS/nixpkgs/commit/404155c6acfa59456aebe6156b22fe385e7dec6f
#
# move `libgcc_s.so` into its own output, `$libgcc`
+ lib.optionalString enableLibGccOutput (''
# move libgcc from lib to its own output (libgcc)
mkdir -p $libgcc/lib
mv $lib/${targetPlatformSlash}lib/libgcc_s.so $libgcc/lib/
mv $lib/${targetPlatformSlash}lib/libgcc_s.so.${libgcc_s-version-major} $libgcc/lib/
ln -s $libgcc/lib/libgcc_s.so $lib/${targetPlatformSlash}lib/
ln -s $libgcc/lib/libgcc_s.so.${libgcc_s-version-major} $lib/${targetPlatformSlash}lib/
''
#
# Nixpkgs ordinarily turns dynamic linking into pseudo-static linking:
# libraries are still loaded dynamically, exactly which copy of each
# library is loaded is permanently fixed at compile time (via RUNPATH).
# For libgcc_s we must revert to the "impure dynamic linking" style found
# in imperative software distributions. We must do this because
# `libgcc_s` calls `malloc()` and therefore has a `DT_NEEDED` for `libc`,
# which creates two problems:
#
# 1. A circular package dependency `glibc`<-`libgcc`<-`glibc`
#
# 2. According to the `-Wl,-rpath` flags added by Nixpkgs' `ld-wrapper`,
# the two versions of `glibc` in the cycle above are actually
# different packages. The later one is compiled by this `gcc`, but
# the earlier one was compiled by the compiler *that compiled* this
# `gcc` (usually the bootstrapFiles). In any event, the `glibc`
# dynamic loader won't honor that specificity without namespaced
# manual loads (`dlmopen()`). Once a `libc` is present in the address
# space of a process, that `libc` will be used to satisfy all
# `DT_NEEDED`s for `libc`, regardless of `RUNPATH`s.
#
# So we wipe the RUNPATH using `patchelf --set-rpath ""`. We can't use
# `patchelf --remove-rpath`, because at least as of patchelf 0.15.0 it
# will leave the old RUNPATH string in the file where the reference
# scanner can still find it:
#
# https://github.com/NixOS/patchelf/issues/453
#
# Note: we might be using the bootstrapFiles' copy of patchelf, so we have
# to keep doing it this way until both the issue is fixed *and* all the
# bootstrapFiles are regenerated, on every platform.
#
# This patchelfing is *not* effectively equivalent to copying
# `libgcc_s` into `glibc`'s outpath. There is one minor and one
# major difference:
#
# 1. (Minor): multiple builds of `glibc` (say, with different
# overrides or parameters) will all reference a single store
# path:
#
# /nix/store/xxx...xxx-gcc-libgcc/lib/libgcc_s.so.1
#
# This many-to-one referrer relationship will be visible in the store's
# dependency graph, and will be available to `nix-store -q` queries.
# Copying `libgcc_s` into each of its referrers would lose that
# information.
#
# 2. (Major): by referencing `libgcc_s.so.1`, rather than copying it, we
# are still able to run `nix-store -qd` on it to find out how it got
# built! Most importantly, we can see from that deriver which compiler
# was used to build it (or if it is part of the unpacked
# bootstrap-files). Copying `libgcc_s.so.1` from one outpath to
# another eliminates the ability to make these queries.
#
+ ''
patchelf --set-rpath "" $libgcc/lib/libgcc_s.so.${libgcc_s-version-major}
'');
}))]))
|