nixpkgs/pkgs/build-support/setup-hooks/make-wrapper.sh

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# Assert that FILE exists and is executable
#
# assertExecutable FILE
assertExecutable() {
local file="$1"
[[ -f "$file" && -x "$file" ]] || \
die "Cannot wrap '$file' because it is not an executable file"
}
# construct an executable file that wraps the actual executable
# makeWrapper EXECUTABLE OUT_PATH ARGS
# ARGS:
# --argv0 NAME : set the name of the executed process to NAME
# (if unset or empty, defaults to EXECUTABLE)
# --inherit-argv0 : the executable inherits argv0 from the wrapper.
# (use instead of --argv0 '$0')
# --set VAR VAL : add VAR with value VAL to the executable's environment
# --set-default VAR VAL : like --set, but only adds VAR if not already set in
# the environment
# --unset VAR : remove VAR from the environment
# --chdir DIR : change working directory (use instead of --run "cd DIR")
# --run COMMAND : run command before the executable
# --add-flags ARGS : prepend ARGS to the invocation of the executable
# (that is, *before* any arguments passed on the command line)
# --append-flags ARGS : append ARGS to the invocation of the executable
# (that is, *after* any arguments passed on the command line)
# --prefix ENV SEP VAL : suffix/prefix ENV with VAL, separated by SEP
# --suffix
# --prefix-each ENV SEP VALS : like --prefix, but VALS is a list
# --suffix-each ENV SEP VALS : like --suffix, but VALS is a list
# --prefix-contents ENV SEP FILES : like --suffix-each, but contents of FILES
# are read first and used as VALS
# --suffix-contents
makeWrapper() { makeShellWrapper "$@"; }
makeShellWrapper() {
local original="$1"
local wrapper="$2"
local params varName value command separator n fileNames
local argv0 flagsBefore flagsAfter flags
assertExecutable "$original"
# Write wrapper code which adds `value` to the beginning or end of
# the list variable named by `varName`, depending on the `mode`
# specified.
#
# A value which is already part of the list will not be added
# again. If this is the case and the `suffix` mode is used, the
# list won't be touched at all. The `prefix` mode will however
# move the last matching instance of the value to the beginning
# of the list. Any remaining duplicates of the value will be left
# as-is.
addValue() {
local mode="$1" # `prefix` or `suffix` to add to the beginning or end respectively
local varName="$2" # name of list variable to add to
local separator="$3" # character used to separate elements of list
local value="$4" # one value, or multiple values separated by `separator`, to add to list
# Disable file globbing, since bash will otherwise try to find
# filenames matching the the value to be prefixed/suffixed if
# it contains characters considered wildcards, such as `?` and
# `*`. We want the value as is, except we also want to split
# it on on the separator; hence we can't quote it.
local reenableGlob=0
if [[ ! -o noglob ]]; then
reenableGlob=1
fi
set -o noglob
if [[ -n "$value" ]]; then
local old_ifs=$IFS
IFS=$separator
if [[ "$mode" == '--prefix'* ]]; then
# Keep the order of the components as written when
# prefixing; normally, they would be added in the
# reverse order.
local tmp=
for v in $value; do
tmp=$v${tmp:+$separator}$tmp
done
value="$tmp"
fi
for v in $value; do
{
echo "$varName=\${$varName:+${separator@Q}\$$varName${separator@Q}}" # add separators on both ends unless empty
if [[ "$mode" == '--prefix'* ]]; then # -- in prefix mode --
echo "$varName=\${$varName/${separator@Q}${v@Q}${separator@Q}/${separator@Q}}" # remove the first instance of the value (if any)
echo "$varName=${v@Q}\$$varName" # prepend the value
elif [[ "$mode" == '--suffix'* ]]; then # -- in suffix mode --
echo "if [[ \$$varName != *${separator@Q}${v@Q}${separator@Q}* ]]; then" # if the value isn't already in the list
echo " $varName=\$$varName${v@Q}" # append the value
echo "fi"
else
echo "unknown mode $mode!" 1>&2
exit 1
fi
echo "$varName=\${$varName#${separator@Q}}" # remove leading separator
echo "$varName=\${$varName%${separator@Q}}" # remove trailing separator
echo "export $varName"
} >> "$wrapper"
done
IFS=$old_ifs
fi
if (( reenableGlob )); then
set +o noglob
fi
}
mkdir -p "$(dirname "$wrapper")"
echo "#! @shell@ -e" > "$wrapper"
params=("$@")
for ((n = 2; n < ${#params[*]}; n += 1)); do
p="${params[$n]}"
if [[ "$p" == "--set" ]]; then
varName="${params[$((n + 1))]}"
value="${params[$((n + 2))]}"
n=$((n + 2))
echo "export $varName=${value@Q}" >> "$wrapper"
elif [[ "$p" == "--set-default" ]]; then
varName="${params[$((n + 1))]}"
value="${params[$((n + 2))]}"
n=$((n + 2))
echo "export $varName=\${$varName-${value@Q}}" >> "$wrapper"
elif [[ "$p" == "--unset" ]]; then
varName="${params[$((n + 1))]}"
n=$((n + 1))
echo "unset $varName" >> "$wrapper"
elif [[ "$p" == "--chdir" ]]; then
dir="${params[$((n + 1))]}"
n=$((n + 1))
echo "cd ${dir@Q}" >> "$wrapper"
elif [[ "$p" == "--run" ]]; then
command="${params[$((n + 1))]}"
n=$((n + 1))
echo "$command" >> "$wrapper"
elif [[ ("$p" == "--suffix") || ("$p" == "--prefix") ]]; then
varName="${params[$((n + 1))]}"
separator="${params[$((n + 2))]}"
value="${params[$((n + 3))]}"
n=$((n + 3))
addValue "$p" "$varName" "$separator" "$value"
elif [[ ("$p" == "--suffix-each") || ("$p" == "--prefix-each") ]]; then
varName="${params[$((n + 1))]}"
separator="${params[$((n + 2))]}"
values="${params[$((n + 3))]}"
n=$((n + 3))
for value in $values; do
addValue "$p" "$varName" "$separator" "$value"
done
elif [[ ("$p" == "--suffix-contents") || ("$p" == "--prefix-contents") ]]; then
varName="${params[$((n + 1))]}"
separator="${params[$((n + 2))]}"
fileNames="${params[$((n + 3))]}"
n=$((n + 3))
for fileName in $fileNames; do
contents="$(cat "$fileName")"
addValue "$p" "$varName" "$separator" "$contents"
done
elif [[ "$p" == "--add-flags" ]]; then
flags="${params[$((n + 1))]}"
n=$((n + 1))
flagsBefore="${flagsBefore-} $flags"
elif [[ "$p" == "--append-flags" ]]; then
flags="${params[$((n + 1))]}"
n=$((n + 1))
flagsAfter="${flagsAfter-} $flags"
elif [[ "$p" == "--argv0" ]]; then
argv0="${params[$((n + 1))]}"
n=$((n + 1))
elif [[ "$p" == "--inherit-argv0" ]]; then
# Whichever comes last of --argv0 and --inherit-argv0 wins
argv0='$0'
else
die "makeWrapper doesn't understand the arg $p"
fi
done
echo exec ${argv0:+-a \"$argv0\"} \""$original"\" \
"${flagsBefore-}" '"$@"' "${flagsAfter-}" >> "$wrapper"
chmod +x "$wrapper"
}
addSuffix() {
suffix="$1"
shift
for name in "$@"; do
echo "$name$suffix"
done
}
filterExisting() {
for fn in "$@"; do
if test -e "$fn"; then
echo "$fn"
fi
done
}
# Syntax: wrapProgram <PROGRAM> <MAKE-WRAPPER FLAGS...>
wrapProgram() { wrapProgramShell "$@"; }
wrapProgramShell() {
local prog="$1"
local hidden
assertExecutable "$prog"
hidden="$(dirname "$prog")/.$(basename "$prog")"-wrapped
while [ -e "$hidden" ]; do
hidden="${hidden}_"
done
mv "$prog" "$hidden"
makeShellWrapper "$hidden" "$prog" --inherit-argv0 "${@:2}"
}