gmid/configure

#!/bin/sh
#
# Copyright (c) 2021 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.

# adapted from mandoc configure and oconfigure, thanks schwarze@ and
# kristaps@!

set -e

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

# Output file descriptor usage:
# 1 (stdout): config.h, Makefile.local
# 2 (stderr): original stderr, usually to the console
# 3: config.log

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

# --------
# default settings: initialize all vars here

CC=cc
CFLAGS=
LDFLAGS=-ltls
YACC=yacc
LEX=lex
STATIC=

HAVE_ERR=
HAVE_GETPROGNAME=
HAVE_LIBTLS=
HAVE_STRLCAT=
HAVE_STRLCPY=
HAVE_VASPRINTF=

NEED_GNU_SOURCE=0
NEED_OPENBSD_SOURCE=0

PREFIX="/usr/local"
BINDIR=

INSTALL="install"

# try to auto detect CFLAGS and LDFLAGS
if which pkg-config 2>/dev/null 1>&2 && pkg-config libtls; then
	CFLAGS=`pkg-config --cflags libtls`
	LDFLAGS=`pkg-config --libs  libtls`
fi

# auto detect lex/flex
which ${LEX} 2>/dev/null 1>&2 || {
	echo "${LEX} not found: trying flex" 1>&2
	echo "${LEX} not found: trying flex" 1>&3
	LEX=flex
	which ${LEX} 2>/dev/null 1>&2 || {
		echo "${LEX} not found: giving up" 1>&2
		echo "${LEX} not found: giving up" 1>&3
		exit 1
	}
}

# auto detect yacc/bison
which ${YACC} 2>/dev/null 1>&2 || {
	echo "${YACC} not found: trying bison" 1>&2
	echo "${YACC} not found: trying bison" 1>&3
	YACC=bison
	which ${YACC} 2>/dev/null 1>&2 || {
		echo "${YACC} not found: giving up" 1>&2
		echo "${YACC} not found: giving up" 1>&3
		exit 1
	}
}

# --------
# allow certain variables to be overridden on the command line

for keyvals in "$@"; do
	key=`echo $keyvals | cut -s -d '=' -f1`
	if [ -z "$key" ]; then
		echo "$0: invalid key-value: $keyvals" 1>&2
		exit 1
	fi
	val=`echo $keyvals | cut -d '=' -f 2-`
	case "$key" in
		BINDIR)  BINDIR="$val" ;;
		CC)      CC="$val" ;;
		CFLAGS)  CFLAGS="$val" ;;
		DESTDIR) DESTDIR="$val" ;;
		LDFLAGS) LDFLAGS="$val" ;;
		LEX)     LEX="$lex" ;;
		PREFIX)  PREFIX="$val" ;;
		YACC)    YACC="$val" ;;
		*)
			echo "$0: invalid key: $key" 1>&2
			exit 1
	esac
done

# --------
# tests functions

# Check whether this HAVE_ setting is manually overridden.
# If yes, use the override, if no, do not decide anything yet.
# Arguments: test file name, test var name, manual value
ismanual() {
	[ -z "${3}" ] && return 1
	echo "tested ${1}: HAVE_${2}=${3} (manual)" 1>&2
	echo "tested ${1}: HAVE_${2}=${3} (manual)" 1>&3
	echo 1>&3
	return 0
}

# Run a single autoconfiguration test.
# In case of success, enable the feature.
# In case of failure, do not decide anything yet.
# Arguments: test file name, test var name, additional CFLAGS
singletest() {
	n=${1}${3}
	cat 1>&3 << __HEREDOC__
testing ${n} ...
${COMP} -o have/${1} have/${1}.c ${3} ${LDFLAGS}
__HEREDOC__

	if ${COMP} -o "have/${1}" "have/${1}.c" ${3} ${LDFLAGS} 1>&3 2>&3
	then
		echo "partial result of ${n}: ${CC} succeeded" 1>&3
	else
		echo "tested ${n}: no (compilation failed)" 1>&2
		echo "result of ${n}: ${CC} failed with exit status $?" 1>&3
		echo "result of compiling ${n}: no" 1>&3
		echo 1>&3
		return 1
	fi

	if ./have/${1} 1>&3 2>&3; then
		echo "tested ${n}: yes" 1>&2
		echo "result of running ${n}: yes" 1>&3
		echo 1>&3
		eval HAVE_${2}=1
		[ "${3}" = "-D_GNU_SOURCE" ] && NEED_GNU_SOURCE=1
		[ "${3}" = "-D_OPENBSD_SOURCE" ] && NEED_OPENBSD_SOURCE=1
		[ "${3}" = "-lsocket" ] && LD_RECVMSG="-lsocket"
		rm "have/${1}"
		return 0
	else
		echo "tested ${n}: no (execution failed)" 1>&2
		echo "result of ${n}: execution failed with exit status $?" 1>&3
		echo "result of running ${n}: no" 1>&3
		echo 1>&3
		rm "have/${1}"
		return 1
	fi
}

# Run a complete autoconfiguration test, including the check for
# a manual override and disabling the feature on failure.
# Arguments: test file name, test var name, additional CFLAGS
# The final argument can optionally be repeated a second time.
runtest() {
	eval _manual=\${HAVE_${2}}
	ismanual "${1}" "${2}" "${_manual}" && return 0
	singletest "${1}" "${2}" "${3}" && return 0
	[ -n "${4}" ] && singletest "${1}" "${2}" "${4}" && return 0
	eval HAVE_${2}=0
	return 1
}

# --------
# compiler options

DEFCFLAGS="-g -W -Wall -Wmissing-prototypes -Wstrict-prototypes -Wwrite-strings -Wno-unused-parameter"

if [ -n "${CFLAGS}" ]; then
	COMP="${CC} ${CFLAGS} -Wno-unused -Werror"
else
	COMP="${CC} ${CDEFCFLAGS} -Wno-unused -Werror"
fi
echo -n "testing ${CC} -W: " 1>&2
echo -n "testing ${CC} -W: " 1>&3
runtest noop WFLAG || true

if [ -n "${CFLAGS}" ]; then
	echo "CFLAGS specified manually:" 1>&3
elif [ ${HAVE_WFLAG} -eq 0 ]; then
	CFLAGS="-g"
else
	CFLAGS="${DEFCFLAGS}"
fi
echo "selected CFLAGS=\"${CFLAGS}\"" 1>&2
echo "selected CFLAGS=\"${CFLAGS}\"" 1>&3
echo 1>&3

COMP="${CC} ${CFLAGS}"
[ ${HAVE_WFLAG} -eq 0 ] || COMP="${COMP} -Wno-unused -Werror"

if [ -n "${STATIC}" ]; then
	echo "selected STATIC=\"${STATIC}\" (manual)" 1>&2
	echo "selected STATIC=\"${STATIC}\" (manual)" 1>&3
	echo 1>&3
else
	runtest noop STATIC -static || true
	[ ${HAVE_STATIC} -eq 0 ] || STATIC="-static"
	echo "selected STATIC=\"${STATIC}\"" 1>&2
	echo "selected STATIC=\"${STATIC}\"" 1>&3
	echo 1>&3
fi

# --------
# tests for config.h

runtest err		ERR		|| true
runtest libtls		LIBTLS		|| true
runtest strlcat		STRLCAT		|| true
runtest strlcpy		STRLCPY		|| true
runtest vasprintf	VASPRINTF	"" -D_GNU_SOURCE || true

if [ ${HAVE_LIBTLS} -eq 0 ]; then
	echo "FATAL: libtls not found" 1>&2
	echo "FATAL: libtls not found" 1>&3
	exit 1
fi

# --------
# write config.h

exec > config.h

cat <<__HEREDOC__
#ifdef __cplusplus
#error "Do not use C++."
#endif

__HEREDOC__

[ ${NEED_GNU_SOURCE} -eq 0 ] || echo "#define _GNU_SOURCE"
[ ${NEED_OPENBSD_SOURCE} -eq 0 ] || echo "#define _OPENBSD_SOURCE"

[ ${HAVE_STRLCAT} -eq 0 -o ${HAVE_STRLCPY} -eq 0 ] \
	&& echo "#include <sys/types.h>"
[ ${HAVE_VASPRINTF} -eq 0 ] && echo "#include <stdarg.h>"

cat <<__HEREDOC__

#define HAVE_ERR		${HAVE_ERR}
#define HAVE_GETPROGNAME	${HAVE_GETPROGNAME}
#define HAVE_STRLCAT		${HAVE_STRLCAT}
#define HAVE_STRLCPY		${HAVE_STRLCPY}
#define HAVE_VASPRINTF		${HAVE_VASPRINTF}

__HEREDOC__

if [ ${HAVE_ERR} -eq 0 ]; then
	echo "extern	void	 err(int, const char*, ...);"
	echo "extern	void	 errx(int, const char*, ...);"
	echo "extern	void	 warn(const char*, ...);"
	echo "extern	void	 warnx(const char*, ...);"
	COMPAT="${COMPAT} compat/err.o"
fi

if [ ${HAVE_STRLCAT} -eq 0 ]; then
	echo "extern	size_t	 strlcat(char*, const char*, size_t);"
	COMPAT="${COMPAT} compat/strlcat.o"
fi
if [ ${HAVE_STRLCPY} -eq 0 ]; then
	echo "extern	size_t	 strlcpy(char*, const char*, size_t);"
	COMPAT="${COMPAT} compat/strlcpy.o"
fi
if [ ${HAVE_VASPRINTF} -eq 0 ]; then
	echo "extern	int	 vasprintf(char**, const char*, va_list);"
	COMPAT="${COMPAT} compat/vasprintf.o"
fi
echo "file config.h: written" 1>&2
echo "file config.h: written" 1>&3

# --------
# tests for Makefile.local

exec > Makefile.local

[ -z "${BINDIR}"          ] && BINDIR="${PREFIX}/bin"
[ -z "${MANDIR}"          ] && MANDIR="${PREFIX}/man"

[ -z "${INSTALL_PROGRAM}" ] && INSTALL_PROGRAM="${INSTALL} -m 0555"
[ -z "${INSTALL_LIB}"     ] && INSTALL_LIB="${INSTALL} -m 0444"
[ -z "${INSTALL_MAN}"     ] && INSTALL_MAN="${INSTALL} -m 0444"
[ -z "${INSTALL_DATA}"    ] && INSTALL_DATA="${INSTALL} -m 0444"

cat << __HEREDOC__
CC		= ${CC}
CFLAGS		= ${CFLAGS}
LDFLAGS		= ${LDFLAGS}
YACC		= ${YACC}
LEX		= ${LEX}
COMPAT		= ${COMPAT}
STATIC		= ${STATIC}
PREFIX		= ${PREFIX}
BINDIR		= ${BINDIR}
INCLUDEDIR	= ${INCLUDEDIR}
INSTALL		= ${INSTALL}
INSTALL_PROGRAM	= ${INSTALL_PROGRAM}
INSTALL_LIB	= ${INSTALL_LIB}
INSTALL_MAN	= ${INSTALL_MAN}
INSTALL_DATA	= ${INSTALL_DATA}
__HEREDOC__

echo "file Makefile.local: written" 1>&2
echo "file Makefile.local: written" 1>&3

exit 0