#! /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.

OCONFIGURE_VERSION="0.3.8"

#
# This script outputs two files: config.h and Makefile.configure.
# It tries to read from configure.local, which contains predefined
# values we won't autoconfigure.
#
# If you want to use configure with your project, have your GNUmakefile
# or BSDmakefile---whichever---try to import/include Makefile.configure
# at the beginning of the file.
#
# Like so (note no quotes, no period, etc.):
#
#   include Makefile.configure
#
# If it exists, configure was run; otherwise, it wasn't.
#
# You'll probably want to change parts of this file.  I've noted the
# parts that you'll probably change in the section documentation.
#
# See https://github.com/kristapsdz/oconfigure for more.

set -e

# try to be helpful
case "$1" in
--help|-h)
	cat <<EOF
\`configure' configures lstun to adapt to many kinds of systems.

Usage: $0 [-h] [--prefix=path] [VAR=VALUE]...

The options are as follows:

    -h, --help     print this help message

    --prefix=path  equivalent to specifying the PREFIX variable, supported
                   for compatibility with other common "configure" scripts.

Variables available:

    SSH_PROG               absolute path to the ssh(1) binary
    LDADD                  generic linker flags
    LDADD_LIBEVENT         linker flags for libevent
    LDADD_LIBEVENT2        linker flags for libevent2
    LDADD_LIBSOCKET        linker flags for libsocket
    LDFLAGS                extra linker flags
    CPPFLAGS               C preprocessors flags
    DESTDIR                destination directory
    PREFIX                 where to install files
    MANDIR                 where to install man pages (PREFIX/man)
    LIBDIR                 where to install libraries (PREFIX/lib)
    BINDIR                 where to install executables (PREFIX/bin)
    SHAREDIR               where to install misc files (PREFIX/share)
    SBINDIR                where to install system executables (PREFIX/sbin)
    INCLUDEDIR             where to install header files (PREFIX/include)
    PKG_CONFIG             path to the pkg-config program or \`false'

Additionally, the following environment variables are used if set:

    CC        the C compiler to use (defaults to cc, clang or gcc)
    CFLAGS    generic C compiler flags

EOF
	exit 0 ;;
esac

#----------------------------------------------------------------------
# Prepare for running: move aside previous configure runs.
# Output file descriptor usage:
#  1 (stdout): config.h or Makefile.configure
#  2 (stderr): original stderr, usually to the console
#  3: config.log
# You DO NOT want to change this.
#----------------------------------------------------------------------

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

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

# GNU submake prints different output if invoked recursively, which
# messes up CC and CFLAGS detection.  Pass --no-print-directory if
# we have a MAKELEVEL (GNU and FreeBSD make) and the argument is
# allowed.

MAKE_FLAGS=""

if [ -n "${MAKELEVEL}" ]; then
	if [ "${MAKELEVEL}" -gt 0 ] ; then
		MAKE_FLAGS="--no-print-directory"
		echo "all:" | make ${MAKE_FLAGS} -sf - 2>/dev/null || MAKE_FLAGS=""
	fi
fi

if [ -n "$MAKE_FLAGS" ]; then
	echo "GNU submake detected: using --no-print-directory" 1>&2
	echo "GNU submake detected: using --no-print-directory" 1>&3
fi

#----------------------------------------------------------------------
# Initialize all variables here such that nothing can leak in from the
# environment except for CC and CFLAGS, which we might have passed in.
#----------------------------------------------------------------------

CC=`printf "all:\\n\\t@echo \\\$(CC)\\n" | make ${MAKE_FLAGS} -sf -`
CFLAGS=`printf "all:\\n\\t@echo \\\$(CFLAGS)\\n" | make ${MAKE_FLAGS} -sf -`
CFLAGS="${CFLAGS} -g -W -Wall -Wmissing-prototypes -Wstrict-prototypes"
CFLAGS="${CFLAGS} -Wmissing-declarations -Wno-unused-parameter"
CFLAGS="${CFLAGS} -Wno-sign-compare"
LDADD=
LDADD_LIBEVENT=
LDADD_LIBEVENT2=
LDADD_LIB_SOCKET=
LDADD_STATIC=
CPPFLAGS=
LDFLAGS=
DESTDIR=
PREFIX="/usr/local"
BINDIR=
SBINDIR=
INCLUDEDIR=
LIBDIR=
MANDIR=
SHAREDIR=
INSTALL="install"
INSTALL_PROGRAM=
INSTALL_LIB=
INSTALL_MAN=
INSTALL_DATA=
PKG_CONFIG=
SSH_PROG=

# SunOS sets "cc", but this doesn't exist.
# It does have gcc, so try that instead.
# Prefer clang, though.

command -v ${CC} 2>/dev/null 1>&2 || {
	echo "${CC} not found: trying clang" 1>&2
	echo "${CC} not found: trying clang" 1>&3
	CC=clang
	command -v ${CC} 2>/dev/null 1>&2 || {
		echo "${CC} not found: trying gcc" 1>&2
		echo "${CC} not found: trying gcc" 1>&3
		CC=gcc
		command -v ${CC} 2>/dev/null 1>&2 || {
			echo "gcc not found: giving up" 1>&2
			echo "gcc not found: giving up" 1>&3
			exit 1
		}
	}
}

#----------------------------------------------------------------------
# Allow certain variables to be overriden on the command line.
#----------------------------------------------------------------------

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

	if [ "$key" = "--prefix" ]; then
		key=PREFIX
		if [ "$1" = "--prefix" ]; then
			if ! shift 2>&1 >/dev/null; then
				echo "$0: missing value for --prefix" 1>&2
				exit 1
			fi
			val="$1"
		fi
	fi

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

	shift

	case "$key" in
	LDADD)
		LDADD="$val" ;;
	LDADD_LIBEVENT)
		LDADD_LIBEVENT="$val" ;;
	LDADD_LIBEVENT2)
		LDADD_LIBEVENT2="$val" ;;
	LDADD_LIBSOCKET)
		LDADD_LIBSOCKET="$val" ;;
	LDFLAGS)
		LDFLAGS="$val" ;;
	CPPFLAGS)
		CPPFLAGS="$val" ;;
	DESTDIR)
		DESTDIR="$val" ;;
	PREFIX)
		PREFIX="$val" ;;
	MANDIR)
		MANDIR="$val" ;;
	LIBDIR)
		LIBDIR="$val" ;;
	BINDIR)
		BINDIR="$val" ;;
	SHAREDIR)
		SHAREDIR="$val" ;;
	SBINDIR)
		SBINDIR="$val" ;;
	INCLUDEDIR)
		INCLUDEDIR="$val" ;;
	PKG_CONFIG)
		PKG_CONFIG="$val" ;;
	SSH_PROG)
		SSH_PROG="$val" ;;
	*)
		echo "$0: invalid key: $key" 1>&2
		exit 1
	esac
done

test -z "${PKG_CONFIG}" && {
	command -v pkg-config 2>/dev/null >&2 && {
		PKG_CONFIG="$(command -v pkg-config)"
		echo "found pkg-config: $PKG_CONFIG" 1>&2
		echo "found pkg-config: $PKG_CONFIG" 1>&3
	} || {
		PKG_CONFIG=false
		echo "pkg-config not found" 1>&2
		echo "pkg-config not found" 1>&3
	}
}

test -z "${SSH_PROG}" && {
	command -v ssh 2>/dev/null 1>&2 && {
		SSH_PROG="$(command -v ssh)"
		echo "found ssh: $SSH_PROG" 1>&2
		echo "found ssh: $SSH_PROG" 1>&3
	} || {
		echo "ssh not found: giving up" >&2
		echo "ssh not found: giving up" >&3
		exit 1
	}
}


#----------------------------------------------------------------------
# These are the values that will be pushed into config.h after we test
# for whether they're supported or not.
# Each of these must have a runtest(), below.
# Please sort by alpha, for clarity.
# You WANT to change this.
#----------------------------------------------------------------------

HAVE_GETEXECNAME=
HAVE_GETPROGNAME=
HAVE_LIBEVENT=
HAVE_LIBEVENT2=
HAVE_PLEDGE=
HAVE_PROGRAM_INVOCATION_SHORT_NAME=
HAVE_PR_SET_NAME=
HAVE_SO_SPLICE=
HAVE_STRLCAT=
HAVE_STRLCPY=
HAVE_STRTONUM=
HAVE_UNVEIL=
HAVE___PROGNAME=

#----------------------------------------------------------------------
# Allow configure.local to override all variables, default settings,
# command-line arguments, and tested features, above.
# You PROBABLY DO NOT want to change this.
#----------------------------------------------------------------------

if [ -r ./configure.local ]; then
	echo "configure.local: reading..." 1>&2
	echo "configure.local: reading..." 1>&3
	cat ./configure.local 1>&3
	. ./configure.local
else
	echo "configure.local: no (fully automatic configuration)" 1>&2
	echo "configure.local: no (fully automatic configuration)" 1>&3
fi

echo 1>&3

#----------------------------------------------------------------------
# Infrastructure for running tests.
# These consists of a series of functions that will attempt to run the
# given test file and record its exit into a HAVE_xxx variable.
# You DO NOT want to change this.
#----------------------------------------------------------------------

COMP="${CC} ${CFLAGS} ${CPPFLAGS} -Wno-unused -Werror"

# Check whether this HAVE_ setting is manually overridden.
# If yes, use the override, if no, do not decide anything yet.
# Arguments: lower-case test name, manual value

ismanual() {
	[ -z "${3}" ] && return 1
	echo "${1}: manual (HAVE_${2}=${3})" 1>&2
	echo "${1}: manual (HAVE_${2}=${3})" 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: lower-case test name, upper-case test name, additional
# CFLAGS, additional LIBS.

singletest() {
	extralib=""
	pkgcfs=""
	pkglib=""

	cat 1>&3 <<EOF
${1}: testing...
${COMP} -DTEST_${2} ${3} -o test-${1} tests.c ${LDFLAGS} ${4}
EOF
	if ${COMP} -DTEST_${2} ${3} -o "test-${1}" tests.c ${LDFLAGS} ${4} 1>&3 2>&3; then
		echo "${1}: ${CC} succeeded" 1>&3
	else
		if [ -n "${5}" ] ; then
			echo "${1}: ${CC} failed with $? (retrying)" 1>&3
			cat 1>&3 <<EOF
${1}: testing...
${COMP} -DTEST_${2} ${3} -o test-${1} tests.c ${LDFLAGS} ${5}
EOF
			if ${COMP} -DTEST_${2} ${3} -o "test-${1}" tests.c ${LDFLAGS} ${5} 1>&3 2>&3; then
				echo "${1}: ${CC} succeeded" 1>&3
				extralib="(with ${5})"
			else
				test -n "${6}" && ${PKG_CONFIG} "$6"
				if [ $? -eq 0 ]; then
					echo "${1}: ${CC} failed with $? (retrying)" 1>&3
					pkgcfs=$($PKG_CONFIG --cflags "${6}")
					pkglib=$($PKG_CONFIG --libs "${6}")
					cat 1>&3 <<EOF
${1}: testing...
${COMP} -DTEST_${2} ${3} ${pkgcfs} -o test-${1} tests.c ${LDFLAGS} ${pkglib}
EOF
					if ${COMP} -DTEST_${2} ${3} ${pkgcfs} -o test-${1} tests.c ${LDFLAGS} ${pkglib} 1>&3 2>&3; then
						echo "${1}: ${CC} succeeded" 1>&3
						extralib="(with ${pkgcfs} ${pkglib})"
					else
						echo "${1}: ${CC} failed with $?" 1>&3
						echo 1>&3
						return 1
					fi
				else
					echo "${1}: ${CC} failed with $?" 1>&3
					echo 1>&3
					return 1
				fi
			fi
		else
			echo "${1}: ${CC} failed with $?" 1>&3
			echo 1>&3
			return 1
		fi
	fi

	rm -f test-${1}.d

	if [ -n "${pkgcfs}" -o -n "${pkglib}" ]
	then
		CFLAGS="${CFLAGS} ${pkgcfs}"
		eval "LDADD_${2}=\"${pkglib}\""
	elif [ -n "${extralib}" ]
	then
		eval "LDADD_${2}=\"${5}\""
	elif [ -n "${4}" ]
	then
		eval "LDADD_${2}=\"${4}\""
	fi

	echo "${1}: yes ${extralib}" 1>&2
	echo "${1}: yes ${extralib}" 1>&3
	echo 1>&3
	eval HAVE_${2}=1
	rm "test-${1}"
	return 0
}

# Run a complete autoconfiguration test, including the check for
# a manual override and disabling the feature on failure.
# Arguments: lower case name, upper case name, additional CFLAGS,
# additional LDADD, alternative LDADD, pkg-config name.

runtest() {
	eval _manual=\${HAVE_${2}}
	ismanual "${1}" "${2}" "${_manual}" && return 0
	singletest "${1}" "${2}" "${3}" "${4}" "${5}" "${6}" && return 0
	echo "${1}: no" 1>&2
	eval HAVE_${2}=0
	return 1
}

#----------------------------------------------------------------------
# Begin running the tests themselves.
# All of your tests must be defined here.
# Please sort as the HAVE_xxxx values were defined.
# You WANT to change this.
# It consists of the following columns:
#    runtest
#    (1) test file
#    (2) macro to set
#    (3) argument to cc *before* -o
#    (4) argument to cc *after*
#    (5) alternative argument to cc *after*
#    (6) name for pkg-config auto-discovery
#----------------------------------------------------------------------

if runtest -MMD _MMD -MMD; then
	CFLAGS="${CFLAGS} -MMD"
	echo "adding -MMD to CFLAGS" 1>&2
	echo "adding -MMD to CFLAGS" 1>&3
fi

runtest getexecname	GETEXECNAME			  || true
runtest getprogname	GETPROGNAME			  || true

runtest libevent	LIBEVENT "" "" "-levent"	  || \
runtest libevent2	LIBEVENT2 "" "" "-levent_extra -levent_core" "libevent" || true

runtest lib_socket	LIB_SOCKET "" "" "-lsocket -lnsl" || true
runtest pledge		PLEDGE				  || true
runtest program_invocation_short_name	PROGRAM_INVOCATION_SHORT_NAME || true
runtest PR_SET_NAME	PR_SET_NAME			  || true
runtest SO_SPLICE	SO_SPLICE			  || true
runtest static		STATIC "" "-static"		  || true
runtest strlcat		STRLCAT				  || true
runtest strlcpy		STRLCPY				  || true
runtest strtonum	STRTONUM			  || true
runtest unveil		UNVEIL				  || true
runtest __progname	__PROGNAME			  || true

if [ "${HAVE_LIBEVENT}" -eq 0 -a "${HAVE_LIBEVENT2:-0}" -eq 0 ]; then
	echo "Fatal: missing libevent" 1>&2
	echo "Fatal: missing libevent" 1>&3
	exit 1
fi

#----------------------------------------------------------------------
# Output writing: generate the config.h file.
# This file contains all of the HAVE_xxxx variables necessary for
# compiling your source.
# You must include "config.h" BEFORE any other variables.
# You WANT to change this.
#----------------------------------------------------------------------

exec > config.h

# Start with prologue.

cat <<EOF
#ifndef OCONFIGURE_CONFIG_H
#define OCONFIGURE_CONFIG_H

#ifdef __cplusplus
# error "Do not use C++: this is a C application."
#endif
#if !defined(__GNUC__) || (__GNUC__ < 4)
# define __attribute__(x)
#endif
#if defined(__linux__) || defined(__MINT__)
# define _GNU_SOURCE /* memmem, memrchr, setresuid... */
# define _DEFAULT_SOURCE /* le32toh, crypt, ... */
#endif
#if defined(__NetBSD__)
# define _OPENBSD_SOURCE /* reallocarray, etc. */
#endif
#if defined(__sun)
# ifndef _XOPEN_SOURCE /* SunOS already defines */
#  define _XOPEN_SOURCE /* XPGx */
# endif
# define _XOPEN_SOURCE_EXTENDED 1 /* XPG4v2 */
# ifndef __EXTENSIONS__ /* SunOS already defines */
#  define __EXTENSIONS__ /* reallocarray, etc. */
# endif
#endif
#if !defined(__BEGIN_DECLS)
# define __BEGIN_DECLS
#endif
#if !defined(__END_DECLS)
# define __END_DECLS
#endif

EOF

# This is just for size_t, mode_t, and dev_t.
# Most of these functions, in the real world, pull in <string.h> or
# someting that pulls in support for size_t.
# Our function declarations are standalone, so specify them here.

if [ ${HAVE_STRLCAT} -eq 0 -o \
     ${HAVE_STRLCPY} -eq 0 ]
then
	echo "#include <sys/types.h> /* size_t, mode_t, dev_t */ "
	echo
fi

if [ ${HAVE_GETPROGNAME} -eq 0 ]; then
	echo "#include <stdlib.h>"
	echo
fi

if [ ${HAVE_PLEDGE} -eq 0 -o ${HAVE_UNVEIL} -eq 0 ]; then
	echo "#include <unistd.h>"
	echo
fi

if [ ${HAVE_LIBEVENT2:-0} -eq 1 ]; then
	cat <<EOF
#include <event2/event.h>
#include <event2/event_compat.h>
#include <event2/event_struct.h>
#include <event2/buffer.h>
#include <event2/buffer_compat.h>
#include <event2/bufferevent.h>
#include <event2/bufferevent_struct.h>
#include <event2/bufferevent_compat.h>
EOF
fi

if [ ${HAVE_LIBEVENT} -eq 1 ]; then
	cat <<EOF
#include <event.h>
EOF
fi

# Now we handle our HAVE_xxxx values.
# Most will just be defined as 0 or 1.

cat <<EOF

/*
 * Results of configuration feature-testing.
 */
#define HAVE_GETEXECNAME ${HAVE_GETEXECNAME}
#define HAVE_GETPROGNAME ${HAVE_GETPROGNAME}
#define HAVE_PLEDGE ${HAVE_PLEDGE}
#define HAVE_PROGRAM_INVOCATION_SHORT_NAME ${HAVE_PROGRAM_INVOCATION_SHORT_NAME}
#define HAVE_PR_SET_NAME ${HAVE_PR_SET_NAME}
#define HAVE_SO_SPLICE ${HAVE_SO_SPLICE}
#define HAVE_STRLCAT ${HAVE_STRLCAT}
#define HAVE_STRLCPY ${HAVE_STRLCPY}
#define HAVE_STRTONUM ${HAVE_STRTONUM}
#define HAVE_UNVEIL ${HAVE_UNVEIL}
#define HAVE___PROGNAME ${HAVE___PROGNAME}

/* Now we do our function declarations for missing functions. */

#if !HAVE_GETPROGNAME
extern const char *getprogname(void);
#endif

#if !HAVE_PLEDGE
# define pledge(a, b) (0)
#endif

#if !HAVE_STRLCAT
extern size_t strlcat(char *, const char *, size_t);
#endif

#if !HAVE_STRLCPY
extern size_t strlcpy(char *, const char *, size_t);
#endif

#if !HAVE_STRTONUM
extern long long strtonum(const char *, long long, long long, const char **);
#endif

#if !HAVE_UNVEIL
# define unveil(a, b) (0)
#endif

#ifndef __dead
# define __dead __attribute__((noreturn))
#endif

#define SSH_PROG "${SSH_PROG}"

#endif /*!OCONFIGURE_CONFIG_H*/
EOF

echo "config.h: written" 1>&2
echo "config.h: written" 1>&3

#----------------------------------------------------------------------
# Now we go to generate our Makefile.configure.
# This file is simply a bunch of Makefile variables.
# They'll work in both GNUmakefile and BSDmakefile.
# You MIGHT want to change this.
#----------------------------------------------------------------------

exec > Makefile.configure

[ -z "${BINDIR}"     ] && BINDIR="${PREFIX}/bin"
[ -z "${SBINDIR}"    ] && SBINDIR="${PREFIX}/sbin"
[ -z "${INCLUDEDIR}" ] && INCLUDEDIR="${PREFIX}/include"
[ -z "${LIBDIR}"     ] && LIBDIR="${PREFIX}/lib"
[ -z "${MANDIR}"     ] && MANDIR="${PREFIX}/man"
[ -z "${SHAREDIR}"   ] && SHAREDIR="${PREFIX}/share"

[ -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 <<EOF
CC		 = ${CC}
CFLAGS		 = ${CFLAGS}
CPPFLAGS	 = ${CPPFLAGS}
LDADD		 = ${LDADD} ${LDADD_LIB_SOCKET} ${LDADD_LIBEVENT} ${LDADD_LIBEVENT2}
LDADD_STATIC	 = ${LDADD_STATIC}
LDFLAGS		 = ${LDFLAGS}
PREFIX		 = ${PREFIX}
BINDIR		 = ${BINDIR}
SHAREDIR	 = ${SHAREDIR}
SBINDIR		 = ${SBINDIR}
INCLUDEDIR	 = ${INCLUDEDIR}
LIBDIR		 = ${LIBDIR}
MANDIR		 = ${MANDIR}
INSTALL		 = ${INSTALL}
INSTALL_PROGRAM	 = ${INSTALL_PROGRAM}
INSTALL_LIB	 = ${INSTALL_LIB}
INSTALL_MAN	 = ${INSTALL_MAN}
INSTALL_DATA	 = ${INSTALL_DATA}
EOF

echo "Makefile.configure: written" 1>&2
echo "Makefile.configure: written" 1>&3

exit 0