bscpkgs/bsc/setup-hooks/patch-shebangs.sh
2020-06-15 11:54:22 +02:00

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# This setup hook causes the fixup phase to rewrite all script
# interpreter file names (`#! /path') to paths found in $PATH. E.g.,
# /bin/sh will be rewritten to /nix/store/<hash>-some-bash/bin/sh.
# /usr/bin/env gets special treatment so that ".../bin/env python" is
# rewritten to /nix/store/<hash>/bin/python. Interpreters that are
# already in the store are left untouched.
# A script file must be marked as executable, otherwise it will not be
# considered.
fixupOutputHooks+=(patchShebangsAuto)
# Run patch shebangs on a directory or file.
# Can take multiple paths as arguments.
# patchShebangs [--build | --host] PATH...
# Flags:
# --build : Lookup commands available at build-time
# --host : Lookup commands available at runtime
# Example use cases,
# $ patchShebangs --host /nix/store/...-hello-1.0/bin
# $ patchShebangs --build configure
patchShebangs() {
local pathName
if [ "$1" = "--host" ]; then
pathName=HOST_PATH
shift
elif [ "$1" = "--build" ]; then
pathName=PATH
shift
fi
echo "patching script interpreter paths in $@"
local f
local oldPath
local newPath
local arg0
local args
local oldInterpreterLine
local newInterpreterLine
if [ $# -eq 0 ]; then
echo "No arguments supplied to patchShebangs" >&2
return 0
fi
local f
while IFS= read -r -d $'\0' f; do
isScript "$f" || continue
oldInterpreterLine=$(head -1 "$f" | tail -c+3)
read -r oldPath arg0 args <<< "$oldInterpreterLine"
if [ -z "$pathName" ]; then
if [ -n "$strictDeps" ] && [[ "$f" = "$NIX_STORE"* ]]; then
pathName=HOST_PATH
else
pathName=PATH
fi
fi
if $(echo "$oldPath" | grep -q "/bin/env$"); then
# Check for unsupported 'env' functionality:
# - options: something starting with a '-'
# - environment variables: foo=bar
if $(echo "$arg0" | grep -q -- "^-.*\|.*=.*"); then
echo "$f: unsupported interpreter directive \"$oldInterpreterLine\" (set dontPatchShebangs=1 and handle shebang patching yourself)" >&2
exit 1
fi
newPath="$(PATH="${!pathName}" command -v "$arg0" || true)"
else
if [ "$oldPath" = "" ]; then
# If no interpreter is specified linux will use /bin/sh. Set
# oldpath="/bin/sh" so that we get /nix/store/.../sh.
oldPath="/bin/sh"
fi
newPath="$(PATH="${!pathName}" command -v "$(basename "$oldPath")" || true)"
args="$arg0 $args"
fi
# Strip trailing whitespace introduced when no arguments are present
newInterpreterLine="$(echo "$newPath $args" | sed 's/[[:space:]]*$//')"
if [ -n "$oldPath" -a "${oldPath:0:${#NIX_STORE}}" != "$NIX_STORE" ]; then
if [ -n "$newPath" -a "$newPath" != "$oldPath" ]; then
echo "$f: interpreter directive changed from \"$oldInterpreterLine\" to \"$newInterpreterLine\""
# escape the escape chars so that sed doesn't interpret them
escapedInterpreterLine=$(echo "$newInterpreterLine" | sed 's|\\|\\\\|g')
# Preserve times, see: https://github.com/NixOS/nixpkgs/pull/33281
timestamp=$(mktemp)
touch -r "$f" "$timestamp"
sed -i -e "1 s|.*|#\!$escapedInterpreterLine|" "$f"
touch -r "$timestamp" "$f"
rm "$timestamp"
fi
fi
done < <(find "$@" -type f -perm -0100 -print0)
stopNest
}
patchShebangsAuto () {
if [ -z "${dontPatchShebangs-}" -a -e "$prefix" ]; then
# Dev output will end up being run on the build platform. An
# example case of this is sdl2-config. Otherwise, we can just
# use the runtime path (--host).
if [ "$output" != out ] && [ "$output" = "$outputDev" ]; then
patchShebangs --build "$prefix"
else
patchShebangs --host "$prefix"
fi
fi
}