#!/bin/sh
#
# Copyright (c) 2014, 2015, 2016 Ingo Schwarze <schwarze@openbsd.org>
# Copyright (c) 2017, 2018 Kristaps Dzonsons <kristaps@bsd.lv>
# Copyright (c) 2022 Omar Polo <op@omarpolo.com>
#
# Permission to use, copy, modify, and distribute this software for any
# purpose with or without fee is hereby granted, provided that the above
# copyright notice and this permission notice appear in all copies.
#
# THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
# WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
# MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
# ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
# WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
# ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
# OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.

set -e

if command -v yacc 2>/dev/null >&2; then
	YACC=yacc
elif command -v bison 2>/dev/null >&2; then
	YACC=bison
else
	YACC=
fi

while [ $# -gt 0 ]; do
	key="${1%%=*}"
	val="${1#*=}"

	if [ "$1" = "$key" ]; then
		echo "$0: invalid key-value: $1" >&2
		exit 1
	fi

	case "$key" in
	CC)
		CC="$val" ;;
	CFLAGS)
		CFLAGS="$val" ;;
	YACC)
		YACC="$val" ;;
	esac

	shift
done

if [ -z "$YACC" ]; then
	echo "fatal: can't find yacc or bison." >&2
	exit 1
fi

[ -w config.log ] && mv config.log config.log.old

exec 3> config.log
echo "config.log: writing..."

CC="${CC:-cc}"
CFLAGS="${CFLAGS:--O2 -pipe} -I."
LIBS="${LIBS:-}"
LDFLAGS="${LDFLAGS:-}"

COMPATS=

HAVE_ERR=
HAVE_FREEZERO=
HAVE_GETEXECNAME=
HAVE_GETPROGNAME=
HAVE_PLEDGE=
HAVE_REALLOCARRAY=
HAVE_STRLCAT=
HAVE_STRLCPY=
HAVE_STRTONUM=
HAVE_SYS_QUEUE=
HAVE_UNVEIL=
HAVE_VASPRINTF=
HAVE___PROGNAME=

# singletest message var extra-cflags extra-libs
singletest() {
	cat >&3 <<EOF
${1}: testing...
$CC ./../tests/${1}.c -Werror $3 -o test-$1 $LDFLAGS $4
EOF
	if $CC ./../tests/${1}.c -Werror $3 -o test-$1 $LDFLAGS $4 >&3 2>&3; then
		rm -f test-${1} test-${1}.d

		if [ -n "$3" ]; then
			echo "${1}: $CC $3 succeeded" >&3
			echo "${1} ($3): yes"
		elif [ -n "${4}" ]; then
			echo "${1}: $CC $4 succeeded" >&3
			echo "${1} ($4): yes"
		else
			echo "${1}: $CC succeeded" >&3
			echo "${1}: yes"
		fi
		echo >&3

		return 0
	fi

	if [ -n "$3" ]; then
		echo "${1}: $CC $3 failed with $?" >&3
		echo "${1} ($3): no"
	elif [ -n "${4}" ]; then
		echo "${1}: $CC $4 failed with $?" >&3
		echo "${1} ($4): no"
	else
		echo "${1}: $CC failed with $?" >&3
		echo "${1}: no"
	fi
	echo >&3

	return 1
}

# runtest message var extra-cflags extra-libs pkgconfig-name
runtest() {
	if singletest "$1" "$2" "" ""; then
		eval HAVE_${2}=1
		return 0
	fi

	if [ -n "$3" -o -n "$4" ]; then
		echo "retrying with ${3+$3 }$4" >&3
		if singletest "$1" "$2" "$3" "$4"; then
			if [ -n "$3" ]; then
				CFLAGS="$CFLAGS $3"
			fi
			if [ -n "${4}" ]; then
				LIBS="$LIBS $4"
			fi
			eval HAVE_${2}=1
			return 0
		fi
	fi

	if [ -f ./../compat/${1}.c ]; then
		COMPATS="${1}.o $COMPATS"
	fi

	eval HAVE_${2}=0
	return 1
}

if runtest MMD _MMD -MMD >/dev/null; then
	echo "adding -MMD to CFLAGS" >&2
	echo "adding -MMD to CFLAGS" >&3
fi

runtest err		ERR					|| true
runtest freezero	FREEZERO				|| true
runtest getexecname	GETEXECNAME				|| true
runtest getprogname	GETPROGNAME				|| true
runtest pledge		PLEDGE					|| true
runtest reallocarray	REALLOCARRAY -D_OPENBSD_SOURCE		|| true
runtest strlcat		STRLCAT					|| true
runtest strlcpy		STRLCPY					|| true
runtest strtonum	STRTONUM				|| true
runtest sys_queue	SYS_QUEUE				|| true
runtest unveil		UNVEIL					|| true
runtest vasprintf	VASPRINTF -D_GNU_SOURCE			|| true
runtest __progname	__PROGNAME				|| true

if [ "${HAVE_SYS_QUEUE}" -eq 0 ]; then
	CFLAGS="-I ./../compat/sys ${CFLAGS}"
fi

if [ -n "${COMPATS}" ]; then
	CFLAGS="-I ./../compat/ ${CFLAGS}"
fi

exec > config.h
echo "config.h: writing..." >&2

cat <<EOF
#ifndef CONFIG_H
#define CONFIG_H

#ifdef __cplusplus
# error "Do not use C++: this is a C application."
#endif

#define HAVE_ERR		${HAVE_ERR}
#define HAVE_FREEZERO		${HAVE_FREEZERO}
#define HAVE_GETEXECNAME	${HAVE_GETEXECNAME}
#define HAVE_GETPROGNAME	${HAVE_GETPROGNAME}
#define HAVE_PLEDGE		${HAVE_PLEDGE}
#define HAVE_REALLOCARRAY	${HAVE_REALLOCARRAY}
#define HAVE_STRLCAT		${HAVE_STRLCAT}
#define HAVE_STRLCPY		${HAVE_STRLCPY}
#define HAVE_STRTONUM		${HAVE_STRTONUM}
#define HAVE_SYS_QUEUE		${HAVE_SYS_QUEUE}
#define HAVE_UNVEIL		${HAVE_UNVEIL}
#define HAVE_VASPRINTF		${HAVE_VASPRINTF}
#define HAVE___PROGNAME		${HAVE___PROGNAME}

#endif
EOF

exec > config.mk
echo "config.mk: writing..." >&2

cat <<EOF
CC =		${CC}
CFLAGS =	${CFLAGS}
LIBS =		${LIBS}
LDFLAGS =	${LDFLAGS}
YACC =		${YACC}

COBJS =	${COMPATS}

INSTALL=	install
INSTALL_PROGRAM=\${INSTALL} -m 0555
INSTALL_LIB=	\${INSTALL} -m 0444
INSTALL_MAN=	\${INSTALL} -m 0444
INSTALL_DATA=	\${INSTALL} -m 0444

EOF

for c in ${COMPATS}; do
	src="../compat/${c%.o}.c"
	cat <<EOF
$c: $src
	\${CC} \${CFLAGS} -c $src -o \$@
EOF
done

echo "done!" >&2
echo >&2