nixpkgs/pkgs/build-support/setup-hooks/auto-patchelf.sh
aszlig 1cba74dfc1
setup-hooks: Add autoPatchelfHook
I originally wrote this for packaging proprietary games in Vuizvui[1]
but I thought it would be generally useful as we have a fair amount of
proprietary software lurking around in nixpkgs, which are a bit tedious
to maintain, especially when the library dependencies change after an
update.

So this setup hook searches for all ELF executables and libraries in the
resulting output paths after install phase and uses patchelf to set the
RPATH and interpreter according to what dependencies are available
inside the builder.

For example consider something like this:

stdenv.mkDerivation {
  ...
  nativeBuildInputs = [ autoPatchelfHook ];
  buildInputs = [ mesa zlib ];
  ...
}

Whenever for example an executable requires mesa or zlib, the RPATH will
automatically be set to the lib dir of the corresponding dependency.

If the library dependency is required at runtime, an attribute called
runtimeDependencies can be used to list dependencies that are added to
all executables that are discovered unconditionally.

Beside this, it also makes initial packaging of proprietary software
easier, because one no longer has to manually figure out the
dependencies in the first place.

[1]: https://github.com/openlab-aux/vuizvui

Signed-off-by: aszlig <aszlig@nix.build>
Closes: #34506
2018-02-10 00:27:24 +05:30

175 lines
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declare -a autoPatchelfLibs
gatherLibraries() {
autoPatchelfLibs+=("$1/lib")
}
addEnvHooks "$targetOffset" gatherLibraries
isExecutable() {
[ "$(file -b -N --mime-type "$1")" = application/x-executable ]
}
findElfs() {
find "$1" -type f -exec "$SHELL" -c '
while [ -n "$1" ]; do
mimeType="$(file -b -N --mime-type "$1")"
if [ "$mimeType" = application/x-executable \
-o "$mimeType" = application/x-sharedlib ]; then
echo "$1"
fi
shift
done
' -- {} +
}
# We cache dependencies so that we don't need to search through all of them on
# every consecutive call to findDependency.
declare -a cachedDependencies
addToDepCache() {
local existing
for existing in "${cachedDependencies[@]}"; do
if [ "$existing" = "$1" ]; then return; fi
done
cachedDependencies+=("$1")
}
declare -gi depCacheInitialised=0
declare -gi doneRecursiveSearch=0
declare -g foundDependency
getDepsFromSo() {
ldd "$1" 2> /dev/null | sed -n -e 's/[^=]*=> *\(.\+\) \+([^)]*)$/\1/p'
}
populateCacheWithRecursiveDeps() {
local so found foundso
for so in "${cachedDependencies[@]}"; do
for found in $(getDepsFromSo "$so"); do
local libdir="${found%/*}"
local base="${found##*/}"
local soname="${base%.so*}"
for foundso in "${found%/*}/$soname".so*; do
addToDepCache "$foundso"
done
done
done
}
getSoArch() {
objdump -f "$1" | sed -ne 's/^architecture: *\([^,]\+\).*/\1/p'
}
# NOTE: If you want to use this function outside of the autoPatchelf function,
# keep in mind that the dependency cache is only valid inside the subshell
# spawned by the autoPatchelf function, so invoking this directly will possibly
# rebuild the dependency cache. See the autoPatchelf function below for more
# information.
findDependency() {
local filename="$1"
local arch="$2"
local lib dep
if [ $depCacheInitialised -eq 0 ]; then
for lib in "${autoPatchelfLibs[@]}"; do
for so in "$lib/"*.so*; do addToDepCache "$so"; done
done
depCacheInitialised=1
fi
for dep in "${cachedDependencies[@]}"; do
if [ "$filename" = "${dep##*/}" ]; then
if [ "$(getSoArch "$dep")" = "$arch" ]; then
foundDependency="$dep"
return 0
fi
fi
done
# Populate the dependency cache with recursive dependencies *only* if we
# didn't find the right dependency so far and afterwards run findDependency
# again, but this time with $doneRecursiveSearch set to 1 so that it won't
# recurse again (and thus infinitely).
if [ $doneRecursiveSearch -eq 0 ]; then
populateCacheWithRecursiveDeps
doneRecursiveSearch=1
findDependency "$filename" "$arch" || return 1
return 0
fi
return 1
}
autoPatchelfFile() {
local dep rpath="" toPatch="$1"
local interpreter="$(< "$NIX_CC/nix-support/dynamic-linker")"
if isExecutable "$toPatch"; then
patchelf --set-interpreter "$interpreter" "$toPatch"
if [ -n "$runtimeDependencies" ]; then
for dep in $runtimeDependencies; do
rpath="$rpath${rpath:+:}$dep/lib"
done
fi
fi
echo "searching for dependencies of $toPatch" >&2
# We're going to find all dependencies based on ldd output, so we need to
# clear the RPATH first.
patchelf --remove-rpath "$toPatch"
local missing="$(
ldd "$toPatch" 2> /dev/null | \
sed -n -e 's/^[\t ]*\([^ ]\+\) => not found.*/\1/p'
)"
# This ensures that we get the output of all missing dependencies instead
# of failing at the first one, because it's more useful when working on a
# new package where you don't yet know its dependencies.
local -i depNotFound=0
for dep in $missing; do
echo -n " $dep -> " >&2
if findDependency "$dep" "$(getSoArch "$toPatch")"; then
rpath="$rpath${rpath:+:}${foundDependency%/*}"
echo "found: $foundDependency" >&2
else
echo "not found!" >&2
depNotFound=1
fi
done
# This makes sure the builder fails if we didn't find a dependency, because
# the stdenv setup script is run with set -e. The actual error is emitted
# earlier in the previous loop.
[ $depNotFound -eq 0 ]
if [ -n "$rpath" ]; then
echo "setting RPATH to: $rpath" >&2
patchelf --set-rpath "$rpath" "$toPatch"
fi
}
autoPatchelf() {
echo "automatically fixing dependencies for ELF files" >&2
# Add all shared objects of the current output path to the start of
# cachedDependencies so that it's choosen first in findDependency.
cachedDependencies+=(
$(find "$prefix" \! -type d \( -name '*.so' -o -name '*.so.*' \))
)
local elffile
# Here we actually have a subshell, which also means that
# $cachedDependencies is final at this point, so whenever we want to run
# findDependency outside of this, the dependency cache needs to be rebuilt
# from scratch, so keep this in mind if you want to run findDependency
# outside of this function.
findElfs "$prefix" | while read -r elffile; do
autoPatchelfFile "$elffile"
done
}
fixupOutputHooks+=(autoPatchelf)