configure

#!/bin/sh
# Based on the configure script from musl libc, MIT licensed

usage() {
	cat <<EOF
Usage: $0 [OPTION]... [VAR=VALUE]...

To assign environment variables (e.g., CC, CFLAGS...), specify them as
VAR=VALUE.	See below for descriptions of some of the useful variables.

Defaults for the options are specified in brackets.

Configuration:
	--srcdir=DIR						source directory [detected]

Installation directories:
	--prefix=PREFIX				 main installation prefix [/usr/local]
	--exec-prefix=EPREFIX	 installation prefix for executable files [PREFIX]

Fine tuning of the installation directories:
	--bindir=DIR						user executables [EPREFIX/bin]
	--sharedir=DIR					share directories [PREFIX/share]
	--docdir=DIR						misc. documentation [PREFIX/share/doc]
	--mandir=DIR						man pages [PREFIX/share/man]

Some influential environment variables:
	CC											C compiler command [detected]
	CFLAGS									C compiler flags [-Os -pipe ...]
	LDFLAGS								 Linker flags

Use these variables to override the choices made by configure.

EOF
	exit 0
}

# helper functions

quote() {
	tr '\n' ' ' <<EOF | grep '^[-[:alnum:]_=,./:]* $' >/dev/null 2>&1 && {
$1
EOF
		echo "$1"
		return 0
	}
	printf %s\\n "$1" | sed -e "s/'/'\\\\''/g" -e "1s/^/'/" -e "\$s/\$/'/" -e "s#^'\([-[:alnum:]_,./:]*\)=\(.*\)\$#\1='\2#"
}
echo() { printf "%s\n" "$*"; }
fail() {
	echo "$*"
	exit 1
}
fnmatch() { eval "case \"\$2\" in $1) return 0 ;; *) return 1 ;; esac"; }
cmdexists() { type "$1" >/dev/null 2>&1; }
trycc() { test -z "$CC" && cmdexists "$1" && CC=$1; }

stripdir() {
	while eval "fnmatch '*/' \"\${$1}\""; do eval "$1=\${$1%/}"; done
}

tryflag() {
	printf "checking whether compiler accepts %s... " "$2"
	echo "typedef int x;" >"$tmpc"
	if $CC $CFLAGS_TRY $2 -c -o "$tmpo" "$tmpc" >/dev/null 2>&1; then
		printf "yes\n"
		eval "$1=\"\${$1} \$2\""
		eval "$1=\${$1# }"
		return 0
	else
		printf "no\n"
		return 1
	fi
}

tryldflag() {
	printf "checking whether linker accepts %s... " "$2"
	echo "typedef int x;" >"$tmpc"
	if $CC $LDFLAGS_TRY -nostdlib -shared "$2" -o "$tmpo" "$tmpc" >/dev/null 2>&1; then
		printf "yes\n"
		eval "$1=\"\${$1} \$2\""
		eval "$1=\${$1# }"
		return 0
	else
		printf "no\n"
		return 1
	fi
}

check_lpeg() {
	printf "	checking for lpeg... "
	ccflags=$1
	shift
	llflags=$@

	cat >"$tmpc" <<EOF
#include <lua.h>
#include <lualib.h>
#include <lauxlib.h>
#include <assert.h>

int main() {
	lua_State *L = luaL_newstate();
	luaL_openlibs(L);
	int reqRes = luaL_dostring(L, "local t=require('lpeg') return (t~=nil)");
	assert(reqRes == 0);
	return 0;
}
EOF

	if $CC $CFLAGS $ccflags "$tmpc" \
		$LDFLAGS $llflags -o "$tmpo" >/dev/null 2>&1; then
		eval $tmpo >/dev/null 2>&1
		if test $? -eq 0; then
			return 1
		fi
	fi
	return 0
}

check_luautf8() {
	printf "	checking for luautf8... "
	ccflags=$1
	shift
	llflags=$@

	cat >"$tmpc" <<EOF
#include <lua.h>
#include <lualib.h>
#include <lauxlib.h>
#include <assert.h>

int main() {
	lua_State *L = luaL_newstate();
	luaL_openlibs(L);
	int reqRes = luaL_dostring(L, "local t=require('lua-utf8') return (t~=nil)");
	assert(reqRes == 0);
	return 0;
}
EOF

	if $CC $CFLAGS $ccflags "$tmpc" \
		$LDFLAGS $llflags -o "$tmpo" >/dev/null 2>&1; then
		eval $tmpo >/dev/null 2>&1
		if test $? -eq 0; then
			return 1
		fi
	fi
	return 0
}


# start of script

CFLAGS_AUTO=
CFLAGS_TRY=
LDFLAGS_AUTO=
LDFLAGS_TRY=
SRCDIR=
PREFIX=/usr/local
EXEC_PREFIX='$(PREFIX)'
BINDIR='$(EXEC_PREFIX)/bin'
SHAREDIR='$(PREFIX)/share'
DOCDIR='$(PREFIX)/share/doc'
MANDIR='$(PREFIX)/share/man'

for arg; do
	case "$arg" in
	--srcdir=*) SRCDIR=${arg#*=} ;;
	--prefix=*) PREFIX=${arg#*=} ;;
	--exec-prefix=*) EXEC_PREFIX=${arg#*=} ;;
	--bindir=*) BINDIR=${arg#*=} ;;
	--sharedir=*) SHAREDIR=${arg#*=} ;;
	--docdir=*) DOCDIR=${arg#*=} ;;
	--mandir=*) MANDIR=${arg#*=} ;;
	--environment-only) environmentonly=yes ;;
	--enable-* | --disable-* | --with-* | --without-* | --*dir=* | --build=*) ;;
	-*) echo "$0: unknown option $arg" ;;
	CC=*) CC=${arg#*=} ;;
	CFLAGS=*) CFLAGS=${arg#*=} ;;
	CPPFLAGS=*) CPPFLAGS=${arg#*=} ;;
	LDFLAGS=*) LDFLAGS=${arg#*=} ;;
	*=*) ;;
	*) ;;
	esac
done

for i in SRCDIR PREFIX EXEC_PREFIX BINDIR SHAREDIR DOCDIR MANDIR; do
	stripdir $i
done

have_pkgconfig=no
printf "checking for pkg-config... "
cmdexists pkg-config && have_pkgconfig=yes
printf "%s\n" "$have_pkgconfig"

#
# Get the source dir for out-of-tree builds
#
if test -z "$SRCDIR"; then
	SRCDIR="${0%/configure}"
	stripdir SRCDIR
fi
abs_builddir="$(pwd)" || fail "$0: cannot determine working directory"
abs_srcdir="$(cd $SRCDIR && pwd)" || fail "$0: invalid source directory $SRCDIR"
test "$abs_srcdir" = "$abs_builddir" && SRCDIR=.
test "$SRCDIR" != "." -a -f Makefile -a ! -h Makefile && fail "$0: Makefile already exists in the working directory"

#
# Get a temp filename we can use
#
i=0
set -C
while :; do
	i=$(($i + 1))
	tmpc="./conf$$-$PPID-$i.c"
	tmpo="./conf$$-$PPID-$i.o"
	2>|/dev/null >"$tmpc" && break
	test "$i" -gt 50 && fail "$0: cannot create temporary file $tmpc"
done
set +C
trap 'rm -f "$tmpc" "$tmpo"' EXIT QUIT TERM HUP
trap 'rm -f "$tmpc" "$tmpo" && echo && fail "$0: interrupted"' INT

#
# Find a C compiler to use
#
printf "checking for C compiler... "
trycc cc
trycc gcc
trycc clang
printf "after checking %s\n" "$CC"
test -n "$CC" || {
	echo "$0: cannot find a C compiler"
	exit 1
}

printf "checking whether C compiler works... "
echo "typedef int x;" >"$tmpc"
if output=$($CC $CPPFLAGS $CFLAGS -c -o "$tmpo" "$tmpc" 2>&1); then
	printf "yes\n"
else
	printf "no; compiler output follows:\n%s\n" "$output"
	exit 1
fi

tryflag CFLAGS -pipe
tryflag CFLAGS -Wall
tryflag CFLAGS -O2

#dead code elimination
tryflag CFLAGS -ffunction-sections
tryflag CFLAGS -fdata-sections
tryldflag LDFLAGS -Wl,--gc-sections

printf "creating config.mk... "

cmdline=$(quote "$0")
for i; do cmdline="$cmdline $(quote "$i")"; done

exec 3>&1 1>config.mk

cat <<EOF
# This version of config.mk was generated by:
# $cmdline
# Any changes made here will be lost if configure is re-run
ABS_SRCDIR = $abs_srcdir
SRCDIR = $SRCDIR
PREFIX = $PREFIX
EXEC_PREFIX = $EXEC_PREFIX
BINDIR = $BINDIR
DOCPREFIX = $DOCDIR
MANPREFIX = $MANDIR
SHAREPREFIX = $SHAREDIR
CC = $CC
CFLAGS = $CFLAGS
LDFLAGS = $LDFLAGS
CFLAGS_DEBUG = -U_FORTIFY_SOURCE -UNDEBUG -O0 -g3 -ggdb -Wall -Wextra -pedantic -Wno-missing-field-initializers -Wno-unused-parameter
EOF
exec 1>&3 3>&-

printf "done\n"

printf "checking for liblua >= 5.1 ...\n"

cat >"$tmpc" <<EOF
#include <lua.h>
#include <lualib.h>
#include <lauxlib.h>

#if LUA_VERSION_NUM < 501
#error "Need at least Lua 5.1"
#endif

int main(int argc, char *argv[]) {
	lua_State *L = luaL_newstate();
	luaL_openlibs(L);
	lua_close(L);
	return 0;
}
EOF

have_lua="no"
have_lpeg="no"
have_luautf8="no"
for liblua in luajit lua lua5.4 lua5.3 lua5.2 lua-5.4 lua-5.3 lua-5.2 lua54 lua53 lua52; do
	printf " checking for %s... " "$liblua"

	if test "$have_pkgconfig" = "yes"; then
		CFLAGS_LUA=$(pkg-config --cflags $liblua 2>/dev/null)
		LDFLAGS_LUA=$(pkg-config --libs $liblua 2>/dev/null)
	else
		CFLAGS_LUA=""
		LDFLAGS_LUA="-l$liblua -lm -ldl"
	fi

	if test $? -eq 0 && $CC $CFLAGS $CFLAGS_LUA "$tmpc" \
		$LDFLAGS $LDFLAGS_LUA -o "$tmpo" >/dev/null 2>&1; then
		have_lua="yes"
		printf "yes\n"
		check_lpeg $CFLAGS_LUA $LDFLAGS_LUA
		has_lpeg=$?
		if (test $has_lpeg -gt 0); then
			have_lpeg="yes"
			printf "yes\n"
		else
			printf "no\n"
		fi
		check_luautf8 $CFLAGS_LUA $LDFLAGS_LUA
		has_luautf8=$?
		if (test $has_luautf8 -gt 0); then
			have_luautf8="yes"
			printf "yes\n"
		else
			printf "no"
		fi
		if (test $has_luautf8 -gt 0) && (test $has_lpeg -gt 0); then
  			break
		fi
	else
		printf "no"
	fi
	printf "\n"
done

if test $have_lua = "no"; then
	fail "Error: Lua was not found."
fi
if test $have_lpeg = "no"; then
	fail "Error: Lua dependency LPEG was not found in any Lua installation."
fi

have_pcre2="no"
CFLAGS_PCRE2=""
LDFLAGS_PCRE2=""

printf "checking for pcre2..."
if pkg-config --exists check >/dev/null 2>&1; then
	have_pcre2="yes"
	CFLAGS_PCRE2=$(pkg-config --cflags libpcre2-8)
	LDFLAGS_PCRE2=$(pkg-config --libs libpcre2-8)
	echo "yes"
else
	echo "no"
fi

printf "completing config.mk... "

exec 3>&1 1>>config.mk

cat <<EOF
CONFIG_HELP = $CONFIG_HELP
CONFIG_LUA = $CONFIG_LUA
CFLAGS_LUA = $CFLAGS_LUA
LDFLAGS_LUA = $LDFLAGS_LUA
CFLAGS_PCRE2 = $CFLAGS_PCRE2
LDFLAGS_PCRE2 = $LDFLAGS_PCRE2
EOF
exec 1>&3 3>&-

test "$SRCDIR" = "." || ln -sf $SRCDIR/Makefile .

printf "done\n"