#!/bin/sh

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

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.

System types:
  --target=TARGET               configure to run on target TARGET [detected]
  --host=TARGET                 same as --target

Installation directories:
  --prefix=PREFIX               main installation prefix [/]

Fine tuning of the installation directories:
  --dynlibdir=DIR               shared library files [PREFIX/lib]
  --libdir=DIR                  static library files [PREFIX/usr/lib/skalibs]
  --includedir=DIR              include files for the C compiler [PREFIX/usr/include]
  --datadir=DIR                 global configuration files [PREFIX/etc]
  --sysdepdir=DIR               sysdeps directory [PREFIX/usr/lib/skalibs/sysdeps]

Dependencies:
  --with-sysdeps=DIR            use provided sysdeps in DIR [autodetected]
  --with-include=DIR            add DIR to the list of searched directories for headers
  --with-lib=DIR                add DIR to the list of searched directories for static libraries
  --with-dynlib=DIR             add DIR to the list of searched directories for shared libraries

Optional features:
  --disable-shared              do not build shared libraries [enabled]
  --disable-static              do not build static libraries [enabled]
  --enable-slashpackage[=ROOT]  assume /package installation at ROOT [disabled]
  --enable-cross=PREFIX         prefix toolchain executable names with PREFIX [none]

skalibs options:
  --enable-libc-replacements    use independent low-level primitives [disabled]
  --enable-egd=PATH             support an EGD daemon listening on PATH as RNG [disabled]
  --disable-ipv6                do not build IPv6 support [enabled]
  --enable-iopause-select       prefer select() over poll() for iopause implementation [disabled]
  --enable-tai-clock            assume the system clock is TAI-10 instead of UTC [disabled]
  --enable-right-tz             assume the timezone is Olson's right/ instead of posix/ [disabled]
  --enable-clock                use clock_gettime() instead of gettimeofday() [disabled]
  --enable-monotonic            count time with CLOCK_MONOTONIC instead of CLOCK_REALTIME
  --enable-force-devr           assume /dev/random exists and is valid [autodetection takes time]
  --with-default-path=PATH      default executable search path [/usr/bin:/bin]

EOF
  exit 0
}


# Helper functions

# If your system does not have printf, you can comment this, but it is
# generally not a good idea to use echo.
# See http://www.etalabs.net/sh_tricks.html
echo () {
  IFS=" "
  printf %s\\n "$*"
}

quote () {
  tr '\n' ' ' <<EOF | grep '^[-[:alnum:]_=,./:]* $' >/dev/null 2>&1 && { echo "$1" ; return 0 ; }
$1
EOF
  echo "$1" | sed -e "s/'/'\\\\''/g" -e "1s/^/'/" -e "\$s/\$/'/" -e "s#^'\([-[:alnum:]_,./:]*\)=\(.*\)\$#\1='\2#" -e "s|\*/|* /|g"
}

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_AUTO" && cmdexists "$1" && CC_AUTO=$1
}

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

tryflag () {
  echo "Checking whether compiler accepts $2 ..."
  echo "typedef int x;" > "$tmpc"
  if $CC_AUTO "$2" -c -o /dev/null "$tmpc" >/dev/null 2>&1 ; then
    echo "  ... yes"
    eval "$1=\"\${$1} \$2\""
    eval "$1=\${$1# }"
    return 0
  else
    echo "  ... no"
    return 1
  fi
}

tryldflag () {
  echo "Checking whether linker accepts $2 ..."
  echo "typedef int x;" > "$tmpc"
  if $CC_AUTO -nostdlib "$2" -o /dev/null "$tmpc" >/dev/null 2>&1 ; then
    echo "  ... yes"
    eval "$1=\"\${$1} \$2\""
    eval "$1=\${$1# }"
    return 0
  else
    echo "  ... no"
    return 1
  fi
}

choose () {
  echo "Checking whether system has $4..."
  r=true
  case "$1" in
    *c*) $CC_AUTO $CPPFLAGS_AUTO $CFLAGS_AUTO -o try$2.o -c src/sysdeps/try$2.c 2>/dev/null || r=false ;;
  esac
  if $r ; then
    case "$1" in
      *l*) $CC_AUTO $CFLAGS_AUTO $LDFLAGS_AUTO -o try$2 try$2.o $5 2>/dev/null || r=false ;;
    esac
  fi
  if $r ; then
    case "$1" in
     *r*) ./try$2 >/dev/null 2>&1 ; r=$?
          case "$r" in
           111) echo "  ... test crashed, aborting." ; exit 111 ;;
           0) r=true ;;
           *) r=false ;;
          esac
    esac
  fi
  rm -f try$2.o try$2
  if $r ; then
    echo "$2: yes" >> $sysdeps/sysdeps
    echo "#define ${package_macro_name}_HAS$3" >> $sysdeps/sysdeps.h
    echo "  ... yes"
  else
    echo "$2: no" >> $sysdeps/sysdeps
    echo "#undef ${package_macro_name}_HAS$3" >> $sysdeps/sysdeps.h
    echo "  ... no"
  fi
}

trytypesize() {
  echo "Checking size of $3..."
  $CC_AUTO $CPPFLAGS_AUTO $CFLAGS_AUTO $LDFLAGS_AUTO -o trysizeof$1 src/sysdeps/trysizeof$1.c
  type_size=$(./trysizeof$1) || fail "$0: unable to determine size of $3"
  type_bits=$(expr 8 \* $type_size)
  rm -f trysizeof$1
  echo "sizeof$1: $type_size" >> $sysdeps/sysdeps
  echo "#define ${package_macro_name}_SIZEOF$2 $type_size" >> $sysdeps/sysdeps.h
  echo "#define ${package_macro_name}_$2_BITS $type_bits" >> $sysdeps/sysdeps.h
  echo "  ... $type_size"
}

# Actual script

CC_AUTO="$CC"
CFLAGS_AUTO="$CFLAGS"
CPPFLAGS_AUTO="-D_POSIX_C_SOURCE=200809L -D_XOPEN_SOURCE=700 -O2 $CPPFLAGS"
LDFLAGS_AUTO="$LDFLAGS"
LDFLAGS_NOSHARED=
prefix=
dynlibdir='$prefix/lib'
libdir='$prefix/usr/lib/skalibs'
includedir='$prefix/usr/include'
datadir='$prefix/etc'
sysdepdir='$prefix/usr/lib/$package/sysdeps'
sysdeps=
shared=true
static=true
slashpackage=false
replacements=false
egd=
ipv6=true
select=false
taiclock=false
righttz=false
clockrt=false
clockmon=false
forcedevr=false
defaultpath=/usr/bin:/bin
sproot=
home=
exthome=
addincpath=''
addlibspath=''
addlibdpath=''
vpaths=''
vpathd=''
cross="$CROSS_COMPILE"

. package/info

for arg ; do
  case "$arg" in
    --help) usage ;;
    --prefix=*) prefix=${arg#*=} ;;
    --dynlibdir=*) dynlibdir=${arg#*=} ;;
    --libdir=*) libdir=${arg#*=} ;;
    --includedir=*) includedir=${arg#*=} ;;
    --datadir=*) datadir=${arg#*=} ;;
    --sysdepdir=*) sysdepdir=${arg#*=} ;;
    --with-sysdeps=*) sysdeps=${arg#*=} ;;
    --with-include=*) var=${arg#*=} ; stripdir var ; addincpath="$addincpath -I$var" ;;
    --with-lib=*) var=${arg#*=} ; stripdir var ; addlibspath="$addlibspath -L$var" ; vpaths="$vpaths $var" ;;
    --with-dynlib=*) var=${arg#*=} ; stripdir var ; addlibdpath="$addlibdpath -L$var" ; vpathd="$vpathd $var" ;;
    --enable-shared|--enable-shared=yes) shared=true ;;
    --disable-shared|--enable-shared=no) shared=false ;;
    --enable-static|--enable-static=yes) static=true ;;
    --disable-static|--enable-static=no) static=false ;;
    --enable-slashpackage=*) sproot=${arg#*=} ; slashpackage=true ; ;;
    --enable-slashpackage) sproot= ; slashpackage=true ;;
    --disable-slashpackage) sproot= ; slashpackage=false ;;
    --enable-cross=*) cross=${arg#*=} ;;
    --enable-cross) cross= ;;
    --disable-cross) cross= ;;
    --enable-libc-replacements|--enable-libc-replacements=yes) replacements=true ;;
    --disable-libc-replacements|--enable-libc-replacements=no) replacements=false ;;
    --enable-egd=*) egd=${arg#*=} ;;
    --disable-egd) egd= ;;
    --enable-ipv6|--enable-ipv6=yes) ipv6=true ;;
    --disable-ipv6|--enable-ipv6=no) ipv6=false ;;
    --enable-iopause-select|--enable-iopause-select=yes) select=true ;;
    --disable-iopause-select|--enable-iopause-select=no) select=false ;;
    --enable-tai-clock|--enable-tai-clock=yes) taiclock=true ;;
    --disable-tai-clock|--enable-tai-clock=no) taiclock=false ;;
    --enable-right-tz|--enable-right-tz=yes) righttz=true ;;
    --disable-right-tz|--enable-right-tz=no) righttz=false ;;
    --enable-clock|--enable-clock=yes) clockrt=true ;;
    --disable-clock|--enable-clock=no) clockrt=false ;;
    --enable-monotonic|--enable-monotonic=yes) clockmon=true ;;
    --disable-monotonic|--enable-monotonic=no) clockmon=false ;;
    --enable-force-devr|--enable-force-devr=yes) forcedevr=true ;;
    --disable-force-devr|--enable-force-devr=no) forcedevr=false ;;
    --with-default-path=*) defaultpath=${arg#*=} ;;
    --without-default-path) defaultpath=/usr/bin:/bin ;;
    --enable-*|--disable-*|--with-*|--without-*|--*dir=*|--build=*) ;;
    --host=*|--target=*) target=${arg#*=} ;;
    -* ) echo "$0: unknown option $arg" ;;
    *=*) ;;
    *) target=$arg ;;
  esac
done

for i in prefix exec_prefix dynlibdir libdir includedir datadir sysdepdir sysdeps sproot ; do
  eval tmp=\${$i}
  eval $i=$tmp
  stripdir $i
done

# Get usable temp filenames
i=0
set -C
while : ; do
  i=$(($i+1))
  tmpc="./tmp-configure-$$-$PPID-$i.c"
  tmpe="./tmp-configure-$$-$PPID-$i.tmp"
  2>|/dev/null > "$tmpc" && break
  2>|/dev/null > "$tmpe" && break
  test "$i" -gt 50 && fail "$0: cannot create temporary files"
done
set +C
trap 'rm -f "$tmpc" "$tmpe"' EXIT ABRT INT QUIT TERM HUP

# Set slashpackage values
if $slashpackage ; then
  home=${sproot}/package/${category}/${package}-${version}
  exthome=${sproot}/package/${category}/${package}
  sysdepdir=${home}/sysdeps
  binprefix=${home}/command
  extbinprefix=${exthome}/command
  dynlibdir=${home}/library.so
  libdir=${home}/library
  includedir=${home}/include
fi

# Find a C compiler to use
echo "Checking for C compiler..."
trycc ${cross}gcc
trycc ${cross}c99
trycc ${cross}cc
test -n "$CC_AUTO" || { echo "$0: cannot find a C compiler" ; exit 1 ; }
echo "  ... $CC_AUTO"
echo "Checking whether C compiler works... "
echo "typedef int x;" > "$tmpc"
if $CC_AUTO $CPPFLAGS_AUTO $CFLAGS_AUTO -c -o /dev/null "$tmpc" 2>"$tmpe" ; then
  echo "  ... yes"
else
  echo "  ... no. Compiler output follows:"
  cat < "$tmpe"
  exit 1
fi

echo "Checking target system type..."
test -n "$target" || target=$($CC_AUTO -dumpmachine 2>/dev/null) || target=unknown
echo "  ... $target"

tryflag CFLAGS_AUTO -std=c99
tryflag CFLAGS_AUTO -fomit-frame-pointer
tryflag CFLAGS_AUTO -fno-exceptions
tryflag CFLAGS_AUTO -fno-unwind-tables
tryflag CFLAGS_AUTO -fno-asynchronous-unwind-tables
tryflag CFLAGS_AUTO -Wa,--noexecstack
tryflag CFLAGS_AUTO -fno-stack-protector
tryflag CPPFLAGS_AUTO -Werror=implicit-function-declaration
tryflag CPPFLAGS_AUTO -Werror=implicit-int
tryflag CPPFLAGS_AUTO -Werror=pointer-sign
tryflag CPPFLAGS_AUTO -Werror=pointer-arith

if $shared ; then
  tryldflag LDFLAGS_AUTO -Wl,--hash-style=both
fi

if test -n "$sysdeps" ; then
  if test ! -d $sysdeps || test ! -f $sysdeps/target ; then
    echo "$0: error: $sysdeps is not a valid sysdeps directory"
    exit 1
  fi
  if [ "x$target" != "x$(cat $sysdeps/target)" ] ; then
    echo "$0: error: target $target does not match the contents of $sysdepdir/target"
    exit 1
  fi
  echo "Using pre-computed sysdeps in $sysdeps."
  rt_lib=$(cat $sysdeps/rt.lib)
  socket_lib=$(cat $sysdeps/socket.lib)
  sysclock_lib=$(cat $sysdeps/sysclock.lib)
  tainnow_lib=$(cat $sysdeps/tainnow.lib)
  util_lib=$(cat $sysdeps/util.lib)
  if test -n "$egd" ; then
    egd=$(grep -F egd: $sysdeps/sysdeps | cut -d' ' -f2-)
    echo "warning: --enable-egd option ignored, using sysdeps-provided value instead: $egd"
  fi
else
  sysdeps=sysdeps.cfg
  mkdir -p $sysdeps
  echo "$target" > $sysdeps/target
  echo "target: $target" > $sysdeps/sysdeps
  cat <<EOF > $sysdeps/sysdeps.h
/* ISC license. */

#ifndef SYSDEPS_H
#define SYSDEPS_H

#define SKALIBS_TARGET "$target"
EOF

  util_lib=
  echo > $sysdeps/util.lib

  echo "Checking whether socket functions need an additional library..."
  $CC_AUTO $CPPFLAGS_AUTO $CFLAGS_AUTO -c -o trylsock.o src/sysdeps/trylsock.c || fail "$0: compiler cannot compile src/sysdeps/trylsock.c"
  if $CC_AUTO $CFLAGS_AUTO $LDFLAGS_AUTO -o /dev/null trylsock.o 2>/dev/null ; then
    socket_lib=
    echo "  ... no"
  elif $CC_AUTO $CFLAGS_AUTO $LDFLAGS_AUTO -o /dev/null trylsock.o -lsocket 2>/dev/null ; then
    socket_lib=-lsocket
    echo "  ... -lsocket"
  elif $CC_AUTO $CFLAGS_AUTO $LDFLAGS_AUTO -o /dev/null trylsock.o -lsocket -lnsl 2>/dev/null ; then
    socket_lib="-lsocket -lnsl"
    echo "  ... -lsocket -lnsl"
  else
    fail "$0: unable to determine socket.lib sysdep"
  fi
  rm -f trylsock.o
  echo "$socket_lib" > $sysdeps/socket.lib

  echo "Checking whether clock functions are available..."
  rt_lib=
  if $CC_AUTO $CPPFLAGS_AUTO $CFLAGS_AUTO -c -o tryclockrt.o src/sysdeps/tryclockrt.c 2>/dev/null ; then
    if $CC_AUTO $CFLAGS_AUTO $LDFLAGS_AUTO -o /dev/null tryclockrt.o 2>/dev/null ; then
      hasclock=true
      echo "  ... yes"
    elif $CC_AUTO $CFLAGS_AUTO $LDFLAGS_AUTO -o /dev/null tryclockrt.o -lrt 2>/dev/null ; then
      hasclock=true
      echo "  ... yes, with -lrt"
      rt_lib=-lrt
    else
      hasclock=false
    fi
    rm -f tryclockrt.o
  else
    hasclock=false
  fi
  echo "$rt_lib" > $sysdeps/rt.lib
  if $clockrt ; then
    echo "$rt_lib" > $sysdeps/sysclock.lib
    echo "$rt_lib" > $sysdeps/tainnow.lib
  else
    echo > $sysdeps/sysclock.lib
    if $clockmon ; then
      echo "$rt_lib" > $sysdeps/tainnow.lib
    else
      echo > $sysdeps/tainnow.lib
    fi
  fi
  if $hasclock ; then
    rm -f tryclockrt
    echo 'clockrt: yes' >> $sysdeps/sysdeps
    echo "#define ${package_macro_name}_HASCLOCKRT" >> $sysdeps/sysdeps.h
    choose cl clockmon CLOCKMON CLOCK_MONOTONIC $rt_lib
  else
    echo 'clockrt: no' >> $sysdeps/sysdeps
    echo "#undef ${package_macro_name}_HASCLOCKRT" >> $sysdeps/sysdeps.h
    echo '  ... no'
  fi

  echo "Checking system endianness..."
  $CC_AUTO $CPPFLAGS_AUTO $CFLAGS_AUTO -o tryendianness src/sysdeps/tryendianness.c
  endianness=$(./tryendianness) || fail "$0: unable to determine endianness"
  echo "endianness: $endianness" >> $sysdeps/sysdeps
  echo "#define ${package_macro_name}_ENDIANNESS \"$endianness\"" >> $sysdeps/sysdeps.h
  echo "  ... $endianness"
  rm -f tryendianness

  trytypesize ushort USHORT "unsigned short"
  trytypesize uint UINT "unsigned int"
  trytypesize ulong ULONG "unsigned long"
  trytypesize gid GID "gid_t"
  trytypesize time TIME "time_t"
  choose clr accept4 ACCEPT4 'accept4()'
  choose clr ancilautoclose ANCILAUTOCLOSE 'auto-close after fd-passing'
  choose c cmsgcloexec CMSGCLOEXEC 'MSG_CMSG_CLOEXEC'
  choose clr devurandom DEVURANDOM '/dev/urandom'
  choose c eproto EPROTO EPROTO
  choose cl eventfd EVENTFD 'eventfd()'
  choose cl flock FLOCK 'flock()'
  choose cl getpeereid GETPEEREID 'getpeereid()'
  choose cl sopeercred SOPEERCRED 'SO_PEERCRED'
  choose cl getpeerucred GETPEERUCRED 'getpeerucred()'
  choose cl ipv6 IPV6 'IPv6 support' $socket_lib
  choose clr malloc0 MALLOC0 'non-NULL malloc(0)'
  choose c msgdontwait MSGDONTWAIT 'MSG_DONTWAIT'
  choose clr nbwaitall NBWAITALL 'non-blocking MSG_WAITALL'
  choose cl openat OPENAT 'openat()'
  choose cl linkat LINKAT 'linkat()'
  choose clr pipe2 PIPE2 'pipe2()'
  choose cl posixspawn POSIXSPAWN 'posix_spawn()'
  choose clr ppoll PPOLL 'ppoll()'
  choose cl revoke REVOKE 'revoke()'
  choose cl sendfile SENDFILE 'sendfile()'
  choose cl setgroups SETGROUPS 'setgroups()'
  choose cl settimeofday SETTIMEOFDAY 'settimeofday()'
  choose clr signalfd SIGNALFD 'signalfd()'
  choose clr splice SPLICE 'splice()'
  choose cl strcasestr STRCASESTR 'strcasestr()'
  choose c uint64t UINT64T 'uint64_t'

  if $forcedevr ; then
    echo "/dev/random detection override required, assuming it exists and is working."
    echo "devrandom: yes" >> $sysdeps/sysdeps
    echo "#define ${package_macro_name}_HASDEVRANDOM" >> $sysdeps/sysdeps.h
  else
    choose clr devrandom DEVRANDOM /dev/random
  fi
  if test -n "$egd" ; then
    if echo "$egd" | grep -q '[^[:alnum:]/_-]' ; then
      fail "$0: invalid EGD path: $egd"
    fi
    echo "egd: $egd" >> $sysdeps/sysdeps
    echo "#define ${package_macro_name}_HASEGD \"$egd\"" >> $sysdeps/sysdeps.h
  fi
  echo '#endif' >> $sysdeps/sysdeps.h
fi

echo "Copying $sysdeps/sysdeps.h to src/include/${package}/sysdeps.h ..."
cat < $sysdeps/sysdeps.h > src/include/${package}/sysdeps.h
echo "  ... done"

echo "Creating config.mak..."
cmdline=$(quote "$0")
for i ; do cmdline="$cmdline $(quote "$i")" ; done
exec 3>&1 1>config.mak
cat << EOF
# This file was generated by:
# $cmdline
# Any changes made here will be lost if configure is re-run.

target := $target
package := $package
prefix := $prefix
datadir := $datadir
sysdepdir := $sysdepdir
dynlibdir := $dynlibdir
libdir := $libdir
includedir := $includedir
sysdeps := $sysdeps
version := $version
sproot := $sproot
home := $home
exthome := $exthome
ipv6 := $ipv6
RT_LIB := ${rt_lib}
SOCKET_LIB := ${socket_lib}
SYSCLOCK_LIB := ${sysclock_lib}
TAINNOW_LIB := ${tainnow_lib}
UTIL_LIB := ${util_lib}
CC := $CC_AUTO
CFLAGS := $CFLAGS_AUTO
CPPFLAGS := $CPPFLAGS_AUTO
LDFLAGS := $LDFLAGS_AUTO
LDFLAGS_NOSHARED := $LDFLAGS_NOSHARED
CROSS_COMPILE := $cross
EOF
if test -n "$vpaths" ; then
  echo "vpath lib%a$vpaths"
fi
if test -n "$vpathd" ; then
  echo "vpath lib%.so$vpathd"
fi

if $static ; then
  echo "STATIC_LIBS := libskarnet.a"
else
  echo "STATIC_LIBS :="
fi
if $shared ; then
  echo "SHARED_LIBS := libskarnet.so"
else
  echo "SHARED_LIBS :="
fi

exec 1>&3 3>&-
echo "  ... done."

echo "Creating src/include/${package}/config.h..."
mkdir -p -m 0755 src/include/${package}
exec 3>&1 1> src/include/${package}/config.h
cat <<EOF
/* ISC license. */

/* Generated by: $cmdline */

#ifndef ${package_macro_name}_CONFIG_H
#define ${package_macro_name}_CONFIG_H

#define ${package_macro_name}_VERSION "$version"
#define ${package_macro_name}_DEFAULTPATH "$defaultpath"
#define ${package_macro_name}_ETC "$datadir"
#define ${package_macro_name}_SPROOT "$sproot"
#define ${package_macro_name}_HOME "$home"
EOF
if $replacements ; then
  echo "#define ${package_macro_name}_FLAG_REPLACE_LIBC"
else
  echo "#undef ${package_macro_name}_FLAG_REPLACE_LIBC"
fi
if $taiclock ; then
  echo "#define ${package_macro_name}_FLAG_CLOCKISTAI"
else
  echo "#undef ${package_macro_name}_FLAG_CLOCKISTAI"
fi
if $righttz ; then
  echo "#define ${package_macro_name}_FLAG_TZISRIGHT"
else
  echo "#undef ${package_macro_name}_FLAG_TZISRIGHT"
fi
if $clockrt ; then
  echo "#define ${package_macro_name}_FLAG_USERT"
else
  echo "#undef ${package_macro_name}_FLAG_USERT"
fi
if $clockmon ; then
  echo "#define ${package_macro_name}_FLAG_USEMON"
else
  echo "#undef ${package_macro_name}_FLAG_USEMON"
fi
if $ipv6 ; then
  echo "#define ${package_macro_name}_FLAG_WANTIPV6"
else
  echo "#undef ${package_macro_name}_FLAG_WANTIPV6"
fi
if $select ; then
  echo "#define ${package_macro_name}_FLAG_PREFERSELECT"
else
  echo "#undef ${package_macro_name}_FLAG_PREFERSELECT"
fi
if test -n "$egd" ; then
  echo "#define ${package_macro_name}_EGD $egd"
else
  echo "#undef ${package_macro_name}_EGD"
fi

echo
echo "#endif"
exec 1>&3 3>&-
echo "  ... done."