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

255 lines
8.3 KiB
Bash
Raw Blame History

This file contains ambiguous Unicode characters

This file contains Unicode characters that might be confused with other characters. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

# 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"
}
# Generate a binary executable wrapper for wrapping an executable.
# The binary is compiled from generated C-code using gcc.
# makeBinaryWrapper EXECUTABLE OUT_PATH ARGS
# ARGS:
# --argv0 NAME : set name of executed process to NAME
# (otherwise its called …-wrapped)
# --set VAR VAL : add VAR with value VAL to the executables
# 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
# --add-flags FLAGS : add FLAGS to invocation of executable
# --prefix ENV SEP VAL : suffix/prefix ENV with VAL, separated by SEP
# --suffix
# To troubleshoot a binary wrapper after you compiled it,
# use the `strings` command or open the binary file in a text editor.
makeBinaryWrapper() {
assertExecutable "$1"
makeDocumentedCWrapper "$1" "${@:3}" | gcc -Os -x c -o "$2" -
}
# Syntax: wrapProgramBinary <PROGRAM> <MAKE-WRAPPER FLAGS...>
wrapProgramBinary() {
local prog="$1"
local hidden
assertExecutable "$prog"
hidden="$(dirname "$prog")/.$(basename "$prog")"-wrapped
while [ -e "$hidden" ]; do
hidden="${hidden}_"
done
mv "$prog" "$hidden"
# Silence warning about unexpanded $0:
# shellcheck disable=SC2016
makeBinaryWrapper "$hidden" "$prog" --argv0 '$0' "${@:2}"
}
# Generate source code for the wrapper in such a way that the wrapper source code
# will still be readable even after compilation
# makeDocumentedCWrapper EXECUTABLE ARGS
# ARGS: same as makeBinaryWrapper
makeDocumentedCWrapper() {
local src docs
src=$(makeCWrapper "$@")
docs=$(documentationString "$src")
printf '%s\n\n' "$src"
printf '%s\n' "$docs"
}
# makeCWrapper EXECUTABLE ARGS
# ARGS: same as makeBinaryWrapper
makeCWrapper() {
local argv0 n params cmd main flagsBefore flags executable params length
local uses_prefix uses_suffix uses_concat3
executable=$(escapeStringLiteral "$1")
params=("$@")
length=${#params[*]}
for ((n = 1; n < length; n += 1)); do
p="${params[n]}"
case $p in
--set)
cmd=$(setEnv "${params[n + 1]}" "${params[n + 2]}")
main="$main $cmd"$'\n'
n=$((n + 2))
[ $n -ge "$length" ] && main="$main #error makeCWrapper: $p takes 2 arguments"$'\n'
;;
--set-default)
cmd=$(setDefaultEnv "${params[n + 1]}" "${params[n + 2]}")
main="$main $cmd"$'\n'
n=$((n + 2))
[ $n -ge "$length" ] && main="$main #error makeCWrapper: $p takes 2 arguments"$'\n'
;;
--unset)
cmd=$(unsetEnv "${params[n + 1]}")
main="$main $cmd"$'\n'
n=$((n + 1))
[ $n -ge "$length" ] && main="$main #error makeCWrapper: $p takes 1 argument"$'\n'
;;
--prefix)
cmd=$(setEnvPrefix "${params[n + 1]}" "${params[n + 2]}" "${params[n + 3]}")
main="$main $cmd"$'\n'
uses_prefix=1
uses_concat3=1
n=$((n + 3))
[ $n -ge "$length" ] && main="$main #error makeCWrapper: $p takes 3 arguments"$'\n'
;;
--suffix)
cmd=$(setEnvSuffix "${params[n + 1]}" "${params[n + 2]}" "${params[n + 3]}")
main="$main $cmd"$'\n'
uses_suffix=1
uses_concat3=1
n=$((n + 3))
[ $n -ge "$length" ] && main="$main #error makeCWrapper: $p takes 3 arguments"$'\n'
;;
--add-flags)
flags="${params[n + 1]}"
flagsBefore="$flagsBefore $flags"
n=$((n + 1))
[ $n -ge "$length" ] && main="$main #error makeCWrapper: $p takes 1 argument"$'\n'
;;
--argv0)
argv0=$(escapeStringLiteral "${params[n + 1]}")
n=$((n + 1))
[ $n -ge "$length" ] && main="$main #error makeCWrapper: $p takes 1 argument"$'\n'
;;
*) # Using an error macro, we will make sure the compiler gives an understandable error message
main="$main #error makeCWrapper: Uknown argument ${p}"$'\n'
;;
esac
done
# shellcheck disable=SC2086
[ -z "$flagsBefore" ] || main="$main"${main:+$'\n'}$(addFlags $flagsBefore)$'\n'$'\n'
main="$main argv[0] = \"${argv0:-${executable}}\";"$'\n'
main="$main return execv(\"${executable}\", argv);"$'\n'
printf '%s\n' "#include <unistd.h>"
printf '%s\n' "#include <stdlib.h>"
[ -z "$uses_concat3" ] || printf '%s\n' "#include <string.h>"
[ -z "$uses_concat3" ] || printf '\n%s\n' "$(concat3Fn)"
[ -z "$uses_prefix" ] || printf '\n%s\n' "$(setEnvPrefixFn)"
[ -z "$uses_suffix" ] || printf '\n%s\n' "$(setEnvSuffixFn)"
printf '\n%s' "int main(int argc, char **argv) {"
printf '\n%s' "$main"
printf '%s\n' "}"
}
addFlags() {
local result n flag flags var
var="argv_tmp"
flags=("$@")
for ((n = 0; n < ${#flags[*]}; n += 1)); do
flag=$(escapeStringLiteral "${flags[$n]}")
result="$result ${var}[$((n+1))] = \"$flag\";"$'\n'
done
printf ' %s\n' "char **$var = malloc(sizeof(*$var) * ($((n+1)) + argc));"
printf ' %s\n' "${var}[0] = argv[0];"
printf '%s' "$result"
printf ' %s\n' "for (int i = 1; i < argc; ++i) {"
printf ' %s\n' " ${var}[$n + i] = argv[i];"
printf ' %s\n' "}"
printf ' %s\n' "${var}[$n + argc] = NULL;"
printf ' %s\n' "argv = $var;"
}
# prefix ENV SEP VAL
setEnvPrefix() {
local env sep val
env=$(escapeStringLiteral "$1")
sep=$(escapeStringLiteral "$2")
val=$(escapeStringLiteral "$3")
printf '%s' "set_env_prefix(\"$env\", \"$sep\", \"$val\");"
}
# suffix ENV SEP VAL
setEnvSuffix() {
local env sep val
env=$(escapeStringLiteral "$1")
sep=$(escapeStringLiteral "$2")
val=$(escapeStringLiteral "$3")
printf '%s' "set_env_suffix(\"$env\", \"$sep\", \"$val\");"
}
# setEnv KEY VALUE
setEnv() {
local key value
key=$(escapeStringLiteral "$1")
value=$(escapeStringLiteral "$2")
printf '%s' "putenv(\"$key=$value\");"
}
# setDefaultEnv KEY VALUE
setDefaultEnv() {
local key value
key=$(escapeStringLiteral "$1")
value=$(escapeStringLiteral "$2")
printf '%s' "setenv(\"$key\", \"$value\", 0);"
}
# unsetEnv KEY
unsetEnv() {
local key
key=$(escapeStringLiteral "$1")
printf '%s' "unsetenv(\"$key\");"
}
# Put the entire source code into const char* SOURCE_CODE to make it readable after compilation.
# documentationString SOURCE_CODE
documentationString() {
local docs
docs=$(escapeStringLiteral $'\n----------\n// This binary wrapper was compiled from the following generated C-code:\n'"$1"$'\n----------\n')
printf '%s' "const char * SOURCE_CODE = \"$docs\";"
}
# Makes it safe to insert STRING within quotes in a C String Literal.
# escapeStringLiteral STRING
escapeStringLiteral() {
local result
result=${1//$'\\'/$'\\\\'}
result=${result//\"/'\"'}
result=${result//$'\n'/"\n"}
result=${result//$'\r'/"\r"}
printf '%s' "$result"
}
concat3Fn() {
printf '%s' "\
char *concat3(char *x, char *y, char *z) {
int xn = strlen(x);
int yn = strlen(y);
int zn = strlen(z);
char *res = malloc(sizeof(*res)*(xn + yn + zn + 1));
strncpy(res, x, xn);
strncpy(res + xn, y, yn);
strncpy(res + xn + yn, z, zn);
res[xn + yn + zn] = '\0';
return res;
}
"
}
setEnvPrefixFn() {
printf '%s' "\
void set_env_prefix(char *env, char *sep, char *val) {
char *existing = getenv(env);
if (existing) val = concat3(val, sep, existing);
setenv(env, val, 1);
if (existing) free(val);
}
"
}
setEnvSuffixFn() {
printf '%s' "\
void set_env_suffix(char *env, char *sep, char *val) {
char *existing = getenv(env);
if (existing) val = concat3(existing, sep, val);
setenv(env, val, 1);
if (existing) free(val);
}
"
}