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Diffstat (limited to 'pkgs/build-support/setup-hooks/make-binary-wrapper.sh')
| -rw-r--r-- | pkgs/build-support/setup-hooks/make-binary-wrapper.sh | 384 |
1 files changed, 384 insertions, 0 deletions
diff --git a/pkgs/build-support/setup-hooks/make-binary-wrapper.sh b/pkgs/build-support/setup-hooks/make-binary-wrapper.sh new file mode 100644 index 00000000000..abc929cb89d --- /dev/null +++ b/pkgs/build-support/setup-hooks/make-binary-wrapper.sh @@ -0,0 +1,384 @@ + +set -euo pipefail + +# 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. +# makeWrapper EXECUTABLE OUT_PATH ARGS + +# ARGS: +# --argv0 NAME : set name of executed process to NAME +# (otherwise it’s called …-wrapped) +# --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") +# --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. +makeWrapper() { + assertExecutable "$1" + makeDocumentedCWrapper "$1" "${@:3}" | \ + @CC@ \ + -Wall -Werror -Wpedantic \ + -Os \ + -x c \ + -o "$2" - +} + +# Syntax: wrapProgram <PROGRAM> <MAKE-WRAPPER FLAGS...> +wrapProgram() { + 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 $0: + # shellcheck disable=SC2016 + makeWrapper "$hidden" "$prog" --inherit-argv0 "${@:2}" +} + +# Generate source code for the wrapper in such a way that the wrapper inputs +# will still be readable even after compilation +# makeDocumentedCWrapper EXECUTABLE ARGS +# ARGS: same as makeWrapper +makeDocumentedCWrapper() { + local src docs + src=$(makeCWrapper "$@") + docs=$(docstring "$@") + printf '%s\n\n' "$src" + printf '%s\n' "$docs" +} + +# makeCWrapper EXECUTABLE ARGS +# ARGS: same as makeWrapper +makeCWrapper() { + local argv0 inherit_argv0 n params cmd main flagsBefore flags executable length + local uses_prefix uses_suffix uses_assert uses_assert_success uses_stdio uses_asprintf + 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' + uses_stdio=1 + uses_assert_success=1 + n=$((n + 2)) + [ $n -ge "$length" ] && main="$main#error makeCWrapper: $p takes 2 arguments"$'\n' + ;; + --unset) + cmd=$(unsetEnv "${params[n + 1]}") + main="$main$cmd"$'\n' + uses_stdio=1 + uses_assert_success=1 + n=$((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"$'\n' + uses_prefix=1 + uses_asprintf=1 + uses_stdio=1 + uses_assert_success=1 + uses_assert=1 + n=$((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"$'\n' + uses_suffix=1 + uses_asprintf=1 + uses_stdio=1 + uses_assert_success=1 + uses_assert=1 + n=$((n + 3)) + [ $n -ge "$length" ] && main="$main#error makeCWrapper: $p takes 3 arguments"$'\n' + ;; + --chdir) + cmd=$(changeDir "${params[n + 1]}") + main="$main$cmd"$'\n' + uses_stdio=1 + uses_assert_success=1 + n=$((n + 1)) + [ $n -ge "$length" ] && main="$main#error makeCWrapper: $p takes 1 argument"$'\n' + ;; + --add-flags) + flags="${params[n + 1]}" + flagsBefore="$flagsBefore $flags" + uses_assert=1 + n=$((n + 1)) + [ $n -ge "$length" ] && main="$main#error makeCWrapper: $p takes 1 argument"$'\n' + ;; + --argv0) + argv0=$(escapeStringLiteral "${params[n + 1]}") + inherit_argv0= + n=$((n + 1)) + [ $n -ge "$length" ] && main="$main#error makeCWrapper: $p takes 1 argument"$'\n' + ;; + --inherit-argv0) + # Whichever comes last of --argv0 and --inherit-argv0 wins + inherit_argv0=1 + ;; + *) # Using an error macro, we will make sure the compiler gives an understandable error message + main="$main#error makeCWrapper: Unknown argument ${p}"$'\n' + ;; + esac + done + # shellcheck disable=SC2086 + [ -z "$flagsBefore" ] || main="$main"${main:+$'\n'}$(addFlags $flagsBefore)$'\n'$'\n' + [ -z "$inherit_argv0" ] && main="${main}argv[0] = \"${argv0:-${executable}}\";"$'\n' + main="${main}return execv(\"${executable}\", argv);"$'\n' + + [ -z "$uses_asprintf" ] || printf '%s\n' "#define _GNU_SOURCE /* See feature_test_macros(7) */" + printf '%s\n' "#include <unistd.h>" + printf '%s\n' "#include <stdlib.h>" + [ -z "$uses_assert" ] || printf '%s\n' "#include <assert.h>" + [ -z "$uses_stdio" ] || printf '%s\n' "#include <stdio.h>" + [ -z "$uses_assert_success" ] || printf '\n%s\n' "#define assert_success(e) do { if ((e) < 0) { perror(#e); abort(); } } while (0)" + [ -z "$uses_prefix" ] || printf '\n%s\n' "$(setEnvPrefixFn)" + [ -z "$uses_suffix" ] || printf '\n%s\n' "$(setEnvSuffixFn)" + printf '\n%s' "int main(int argc, char **argv) {" + printf '\n%s' "$(indent4 "$main")" + printf '\n%s\n' "}" +} + +addFlags() { + local result n flag flags var + var="argv_tmp" + flags=("$@") + 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 = calloc($((n+1)) + argc, sizeof(*$var));" + printf '%s\n' "assert($var != NULL);" + printf '%s\n' "${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 = $var;" +} + +# chdir DIR +changeDir() { + local dir + dir=$(escapeStringLiteral "$1") + printf '%s' "assert_success(chdir(\"$dir\"));" +} + +# 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\");" + assertValidEnvName "$1" +} + +# suffix ENV SEP VAL +setEnvSuffix() { + local env sep val + env=$(escapeStringLiteral "$1") + sep=$(escapeStringLiteral "$2") + val=$(escapeStringLiteral "$3") + printf '%s' "set_env_suffix(\"$env\", \"$sep\", \"$val\");" + assertValidEnvName "$1" +} + +# setEnv KEY VALUE +setEnv() { + local key value + key=$(escapeStringLiteral "$1") + value=$(escapeStringLiteral "$2") + printf '%s' "putenv(\"$key=$value\");" + assertValidEnvName "$1" +} + +# setDefaultEnv KEY VALUE +setDefaultEnv() { + local key value + key=$(escapeStringLiteral "$1") + value=$(escapeStringLiteral "$2") + printf '%s' "assert_success(setenv(\"$key\", \"$value\", 0));" + assertValidEnvName "$1" +} + +# unsetEnv KEY +unsetEnv() { + local key + key=$(escapeStringLiteral "$1") + printf '%s' "assert_success(unsetenv(\"$key\"));" + assertValidEnvName "$1" +} + +# Makes it safe to insert STRING within quotes in a C String Literal. +# escapeStringLiteral STRING +escapeStringLiteral() { + local result + result=${1//$'\\'/$'\\\\'} + result=${result//\"/'\"'} + result=${result//$'\n'/"\n"} + result=${result//$'\r'/"\r"} + printf '%s' "$result" +} + +# Indents every non-empty line by 4 spaces. To avoid trailing whitespace, we don't indent empty lines +# indent4 TEXT_BLOCK +indent4() { + printf '%s' "$1" | awk '{ if ($0 != "") { print " "$0 } else { print $0 }}' +} + +assertValidEnvName() { + case "$1" in + *=*) printf '\n%s\n' "#error Illegal environment variable name \`$1\` (cannot contain \`=\`)";; + "") printf '\n%s\n' "#error Environment variable name can't be empty.";; + esac +} + +setEnvPrefixFn() { + printf '%s' "\ +void set_env_prefix(char *env, char *sep, char *prefix) { + char *existing = getenv(env); + if (existing) { + char *val; + assert_success(asprintf(&val, \"%s%s%s\", prefix, sep, existing)); + assert_success(setenv(env, val, 1)); + free(val); + } else { + assert_success(setenv(env, prefix, 1)); + } +} +" +} + +setEnvSuffixFn() { + printf '%s' "\ +void set_env_suffix(char *env, char *sep, char *suffix) { + char *existing = getenv(env); + if (existing) { + char *val; + assert_success(asprintf(&val, \"%s%s%s\", existing, sep, suffix)); + assert_success(setenv(env, val, 1)); + free(val); + } else { + assert_success(setenv(env, suffix, 1)); + } +} +" +} + +# Embed a C string which shows up as readable text in the compiled binary wrapper +# documentationString ARGS +docstring() { + printf '%s' "const char * DOCSTRING = \"$(escapeStringLiteral " + + +# ------------------------------------------------------------------------------------ +# The C-code for this binary wrapper has been generated using the following command: + + +makeCWrapper $(formatArgs "$@") + + +# (Use \`nix-shell -p makeBinaryWrapper\` to get access to makeCWrapper in your shell) +# ------------------------------------------------------------------------------------ + + +")\";" +} + +# formatArgs EXECUTABLE ARGS +formatArgs() { + printf '%s' "$1" + shift + while [ $# -gt 0 ]; do + case "$1" in + --set) + formatArgsLine 2 "$@" + shift 2 + ;; + --set-default) + formatArgsLine 2 "$@" + shift 2 + ;; + --unset) + formatArgsLine 1 "$@" + shift 1 + ;; + --prefix) + formatArgsLine 3 "$@" + shift 3 + ;; + --suffix) + formatArgsLine 3 "$@" + shift 3 + ;; + --chdir) + formatArgsLine 1 "$@" + shift 1 + ;; + --add-flags) + formatArgsLine 1 "$@" + shift 1 + ;; + --argv0) + formatArgsLine 1 "$@" + shift 1 + ;; + --inherit-argv0) + formatArgsLine 0 "$@" + ;; + esac + shift + done + printf '%s\n' "" +} + +# formatArgsLine ARG_COUNT ARGS +formatArgsLine() { + local ARG_COUNT LENGTH + ARG_COUNT=$1 + LENGTH=$# + shift + printf '%s' $' \\\n '"$1" + shift + while [ "$ARG_COUNT" -gt $((LENGTH - $# - 2)) ]; do + printf ' %s' "${1@Q}" + shift + done +} |