configure

#!/bin/sh
# Blinkenlights Configuration Script
# Run ./configure --help for usage

CONFIG_COMMAND="$0 $*"

# Evaluate FOO=bar environment variables passed as arguments (carefully
# ignoring --foo=bar flags) and then remove MODE=foo from the arguments
cleared=
for x; do
  test "$cleared" || set -- ; cleared=1
  if [ x"${x%%=*}" != x"$x" ] && [ x"${x#--}" = x"$x" ]; then
    eval "${x%%=*}='${x#*=}'"
  fi
  if [ x"${x%%=*}" != x"MODE" ]; then
    set -- "$@" "$x"
  fi
done

CC="${CC:-cc}"
AR="${AR:-ar}"
PREFIX="/usr/local"
MODE="${MODE:-${m}}"
TMPDIR="${TMPDIR:-o/tmp}"
CFLAGS="${CFLAGS:--g -O2}"
UOPFLAGS="${UOPFLAGS:--O2}"
CPPFLAGS="${CPPFLAGS:--D_FILE_OFFSET_BITS=64 -D_DARWIN_C_SOURCE -D_DEFAULT_SOURCE -D_BSD_SOURCE -D_GNU_SOURCE}"

HOST_ARCH=$(uname -m)
HOST_SYSTEM=$(uname -s)
HOST_OS=$(uname -o 2>/dev/null)

if [ "${HOST_ARCH}" = "amd64" ] ||
   [ "${HOST_ARCH}" = "x86_64" ] ||
   [ "${HOST_ARCH}" = "arm64" ] ||
   [ "${HOST_ARCH}" = "aarch64" ]; then
  JIT_POSSIBLE=1
else
  JIT_POSSIBLE=
fi

if [ "$1" = "--help" ]; then
  echo "usage: ./configure [OPTION]... [VARIABLE=VAL]..."
  echo
  echo "options"
  echo
  echo "  --help"
  echo "    shows this help"
  echo
  echo "  --static"
  echo "    compile blink as a statically-linked binary"
  echo
  echo "  --prefix=PATH"
  echo "    configures system install path (defaults to /usr/local)"
  echo
  echo "  --enable-vfs"
  echo "    enables true filesystem emulation support (overlays alternative)"
  echo
  echo "  --disable-jit"
  echo "    forces jit compilation to be disabled (shaves ~26kb off MODE=tiny)"
  echo
  echo "  --disable-x87"
  echo "    disables x87 fpu and long double support (shaves ~23kb off MODE=tiny)"
  echo
  echo "  --disable-threads"
  echo "    disables clone() and removes locks / barriers (shaves ~12kb off MODE=tiny)"
  echo
  echo "  --disable-sockets"
  echo "    disables socket() and related system calls (shaves ~5kb off MODE=tiny)"
  echo
  if [ "${MODE%%-*}" != "tiny" ] && [ "${MODE%%-*}" != "rel" ] && [ "${MODE%%-*}" != "opt" ]; then
    echo "  --disable-disassembler"
    echo "    disables printing disassembled opcodes on crash (shaves ~48kb off MODE='')"
    echo
    echo "  --disable-strace"
    echo "    disables system call logging functionality (shaves ~40kb off MODE='')"
    echo
    echo "  --disable-backtrace"
    echo "    disables printing guest backtrace on crash (shaves ~5kb off MODE='')"
    echo
  fi
  echo "  --disable-metal"
  echo "    disables i8086, i386, and ring-0 instructions (shaves ~3kb off MODE=tiny)"
  echo
  echo "  --disable-mmx"
  echo "    disables rarely used intel mmx legacy instructions (shaves ~3kb off MODE=tiny)"
  echo
  echo "  --disable-fork"
  echo "    disables fork() and interprocess communication (shaves ~3kb off MODE=tiny)"
  echo
  echo "  --disable-overlays"
  echo "    disables filesystem overlays and chroot() support (shaves ~3kb off MODE=tiny)"
  echo
  echo "  --disable-nonposix"
  echo "    disables linux apis that aren't part of posix (shaves ~6kb off MODE=tiny)"
  echo "    intended for testing compliance of guest programs"
  echo
  echo "  --disable-bmi2"
  echo "    disables bmi2 and adx instruction sets (shaves ~3kb off MODE=tiny)"
  echo
  echo "  --disable-ancillary"
  echo "    disables sendmsg/recvmsg control data support (shaves ~2kb off MODE=tiny)"
  echo
  echo "  --disable-bcd"
  echo "    disables i8086 binary coded decimal support (shaves ~1kb off MODE=tiny)"
  echo
  echo "  --disable-rom"
  echo "    disables write protection of metal bios (shaves ~600 bytes off MODE=tiny)"
  echo
  echo "  --disable-all"
  echo "    disable all optional features (shaves ~81kb off MODE=tiny)"
  echo "    you may use --enable-FOO to turn features back on"
  echo
  echo "  --posix"
  echo "    strictly conform to POSIX.1-2008 XSI and C11 standards (clobbers \$CPPFLAGS)"
  echo "    linux-specific apis are still provided by blink when they can be polyfilled"
  echo "    intended for testing compliance of blink's codebase"
  echo
  echo "variables"
  echo
  echo "  MODE"
  echo "    tunes makefile by choosing a preset configuration. defaults"
  echo "    to empty string which is recommended. may alternatively be"
  echo "    set to: tiny, opt, rel, dbg, cosmo, prof, cov, asan, ubsan,"
  echo "    tsan, msan, llvm, llvm++, rel-llvm, or tiny-llvm."
  echo
  echo "  CC"
  echo "    used to compile and link code [currently: $CC]"
  echo
  echo "  CFLAGS"
  echo "    shall be passed to \$CC when compiling c sources [currently: $CFLAGS]"
  echo
  echo "  CPPFLAGS"
  echo "    shall be passed to \$CC when using the c preprocessor [currently: $CPPFLAGS]"
  echo
  echo "  LDFLAGS"
  echo "    shall be passed to \$CC when linking binaries [currently: $LDFLAGS]"
  echo
  echo "  TARGET_ARCH"
  echo "    shall be passed to \$CC when compiling objects [currently: $TARGET_ARCH]"
  echo
  echo "  LOADLIBES"
  echo "    may supply additional libraries to link earlier [currently: $LOADLIBES]"
  echo
  echo "  LDLIBS"
  echo "    may supply additional libraries to link [currently: $LDLIBS]"
  echo
  echo "  TMPDIR"
  echo "    used to store temporary files [currently: $TMPDIR]"
  echo
  echo "  AR"
  echo "    used to create static archives [currently: $AR]"
  echo
  exit 0
fi

if ! [ -f blink/blink.c ]; then
  echo "error: not in blink project root directory" >&2
  echo "please change the current directory" >&2
  exit 1
fi

# POSIX compliant realpath solution for Darwin
# https://stackoverflow.com/a/18443300/1653720
realpath() (
  OURPWD=$PWD
  cd "$(dirname "$1")"
  LINK=$(readlink "$(basename "$1")")
  while [ "$LINK" ]; do
    cd "$(dirname "$LINK")"
    LINK=$(readlink "$(basename "$1")")
  done
  REALPATH="$PWD/$(basename "$1")"
  cd "$OURPWD"
  echo "$REALPATH"
)

mkdir -p "${TMPDIR}" || exit
mkdir -p o/tool/config || exit
export TMPDIR=$(realpath "$TMPDIR")

printf "checking for flock... " >&2
if command -v flock >/dev/null; then
  echo yes >&2
  FLOCK=flock
elif [ -x o/tool/flock ]; then
  echo o/tool/flock >&2
  FLOCK=o/tool/flock
else
  echo no >&2
  printf "building tool/flock.c... " >&2
  f=$(mktemp "${TMPDIR}/flock.XXXXXX")
  if ${CC} -o "${f}" tool/flock.c; then
    echo ok >&2
    mv -f "${f}" o/tool/flock || exit
    FLOCK=o/tool/flock
  else
    echo "error: need the flock command" >&2
    exit 1
  fi
fi

CONFIG=$(mktemp "${TMPDIR}/blink-config.h.XXXXXX")
BUILD=$(mktemp "${TMPDIR}/blink-config.mk.XXXXXX")
LOCK=$(mktemp "${TMPDIR}/blink-config.lock.XXXXXX")

cp config.h.in "${CONFIG}" || exit
rm -f config.log

run() {
  (
    printf '%s\n' "$*"
    if nice "$@"; then
      exit 0
    else
      rc=$?
      echo "exit code $rc"
      exit $rc
    fi
  ) >&6 2>&6
}

compile() {
  run ${CC:-cc} \
      ${EXTRA_CFLAGS} \
      ${CFLAGS} \
      ${EXTRA_CPPFLAGS} \
      ${CPPFLAGS} \
      ${EXTRA_LDFLAGS} \
      ${LDFLAGS} \
      ${TARGET_ARCH} \
      "$@" \
      ${LOADLIBES} \
      ${EXTRA_LDLIBS} \
      ${LDLIBS}
}

config() {
  PROGRAM="$1"
  # If running on cygwin, msys2 or wsl then enable testing mingw-w64 produced binaries
  if test "${CC#*w64-mingw}" != "${CC}"; then
    RUNPROGRAM="$1.exe"
  elif [ "${HOST_OS}" = "Cygwin" ]; then
    RUNPROGRAM="$1.exe"
  else
    RUNPROGRAM="$1"
  fi
  MESSAGE="$2"
  shift 2
  LOG=$(mktemp "${TMPDIR}/blink-config.log.XXXXXX")
  exec 6<>"${LOG}"
  echo >&6
  echo ======================================================================== >&6
  echo "${MESSAGE}" >&6
  echo ======================================================================== >&6
  echo >&6
  if [ ! -f "tool/config/${PROGRAM}.c" ]; then
    echo "tool/config/${PROGRAM}.c: not found" >&2
    exit 1
  fi
  if compile -Werror -o "o/tool/config/${PROGRAM}" "tool/config/${PROGRAM}.c" &&
     run "o/tool/config/${RUNPROGRAM}"; then
    printf '%s\n' "${MESSAGE} yes" >&2
    if [ $# -gt 0 ]; then
      "$@"
    fi
    rc=0
  else
    printf '%s\n' "${MESSAGE} no" >&2
    rc=1
  fi
  cat <"${LOG}" >>config.log
  rm -f "${LOG}"
  exec 6<&-
  EXTRA_CFLAGS=
  EXTRA_CPPFLAGS=
  EXTRA_LDFLAGS=
  EXTRA_LDLIBS=
  return $rc
}

hassstr() {
  if ! grep "$1" <"${CONFIG}" >/dev/null 2>&1; then
    echo "config.h.in didn't contain $1" >&2
  fi
}

replace() {
  exec 7<>"${LOCK}"
  "${FLOCK}" -x 7
  sed "s@$1@$2@" <"${CONFIG}" >"${CONFIG}.tmp" &&
  mv -f "${CONFIG}.tmp" "${CONFIG}"
  exec 7<&-
}

comment() {
  hassstr "$1"
  replace "$1" "// $1"
}

uncomment() {
  hassstr "$1"
  replace "// $1" "$1"
}

for x; do
  if [ x"${x%=*}" != x"$x" ] && [ x"${x#--}" = x"$x" ]; then
    continue
  fi

  if [ x"$x" = x"--disable-all" ]; then
    uncomment "#define DISABLE"
    DISABLE_NONPOSIX=1
    DISABLE_THREADS=1
    DISABLE_SOCKETS=1
    DISABLE_FORK=1
    DISABLE_X87=1
    DISABLE_JIT=1

  elif [ x"${x%%=*}" = x"--prefix" ]; then
    PREFIX="${x#*=}"

  elif [ x"$x" = x"--static" ]; then
    STATIC=1

  elif [ x"$x" = x"--enable-fork" ]; then
    unset DISABLE_FORK
  elif [ x"$x" = x"--disable-fork" ]; then
    DISABLE_FORK=1

  elif [ x"$x" = x"--enable-jit" ]; then
    comment "#define DISABLE_JIT"
    unset DISABLE_JIT
  elif [ x"$x" = x"--disable-jit" ]; then
    uncomment "#define DISABLE_JIT"
    DISABLE_JIT=1

  elif [ x"$x" = x"--enable-x87" ]; then
    comment "#define DISABLE_X87"
    unset DISABLE_X87
  elif [ x"$x" = x"--disable-x87" ]; then
    uncomment "#define DISABLE_X87"
    DISABLE_X87=1

  elif [ x"$x" = x"--enable-mmx" ]; then
    comment "#define DISABLE_MMX"
  elif [ x"$x" = x"--disable-mmx" ]; then
    uncomment "#define DISABLE_MMX"

  elif [ x"$x" = x"--enable-metal" ]; then
    comment "#define DISABLE_METAL"
  elif [ x"$x" = x"--disable-metal" ]; then
    uncomment "#define DISABLE_METAL"

  elif [ x"$x" = x"--enable-strace" ]; then
    comment "#define DISABLE_STRACE"
  elif [ x"$x" = x"--disable-strace" ]; then
    uncomment "#define DISABLE_STRACE"

  elif [ x"$x" = x"--enable-threads" ]; then
    comment "#define DISABLE_THREADS"
    unset DISABLE_THREADS
  elif [ x"$x" = x"--disable-threads" ]; then
    uncomment "#define DISABLE_THREADS"
    DISABLE_THREADS=1

  elif [ x"$x" = x"--enable-sockets" ]; then
    comment "#define DISABLE_SOCKETS"
    unset DISABLE_SOCKETS
  elif [ x"$x" = x"--disable-sockets" ]; then
    uncomment "#define DISABLE_SOCKETS"
    DISABLE_SOCKETS=1

  elif [ x"$x" = x"--enable-overlays" ]; then
    comment "#define DISABLE_OVERLAYS"
    uncomment "#define DISABLE_VFS"
  elif [ x"$x" = x"--disable-overlays" ]; then
    uncomment "#define DISABLE_OVERLAYS"

  elif [ x"$x" = x"--enable-vfs" ]; then
    comment "#define DISABLE_VFS"
    uncomment "#define DISABLE_OVERLAYS"
  elif [ x"$x" = x"--disable-vfs" ]; then
    uncomment "#define DISABLE_VFS"

  elif [ x"$x" = x"--enable-ancillary" ]; then
    comment "#define DISABLE_ANCILLARY"
  elif [ x"$x" = x"--disable-ancillary" ]; then
    uncomment "#define DISABLE_ANCILLARY"

  elif [ x"$x" = x"--enable-disassembler" ]; then
    comment "#define DISABLE_DISASSEMBLER"
  elif [ x"$x" = x"--disable-disassembler" ]; then
    uncomment "#define DISABLE_DISASSEMBLER"

  elif [ x"$x" = x"--enable-backtrace" ]; then
    comment "#define DISABLE_BACKTRACE"
  elif [ x"$x" = x"--disable-backtrace" ]; then
    uncomment "#define DISABLE_BACKTRACE"

  elif [ x"$x" = x"--enable-nonposix" ]; then
    comment "#define DISABLE_NONPOSIX"
    unset DISABLE_NONPOSIX
  elif [ x"$x" = x"--disable-nonposix" ]; then
    uncomment "#define DISABLE_NONPOSIX"
    DISABLE_NONPOSIX=1

  elif [ x"$x" = x"--enable-bmi2" ]; then
    comment "#define DISABLE_BMI2"
  elif [ x"$x" = x"--disable-bmi2" ]; then
    uncomment "#define DISABLE_BMI2"

  elif [ x"$x" = x"--enable-bcd" ]; then
    comment "#define DISABLE_BCD"
  elif [ x"$x" = x"--disable-bcd" ]; then
    uncomment "#define DISABLE_BCD"

  elif [ x"$x" = x"--enable-rom" ]; then
    comment "#define DISABLE_ROM"
  elif [ x"$x" = x"--disable-rom" ]; then
    uncomment "#define DISABLE_ROM"

  elif [ x"$x" = x"--posix" ]; then
    CPPFLAGS="-D_POSIX_C_SOURCE=200809L -D_XOPEN_SOURCE=700 -std=c11"
    POSIX=1

  elif [ x"$x" = x"--pedantic" ]; then
    CFLAGS="$CFLAGS -std=c11 -pedantic -Wall -Werror"

  else
    echo "error: unrecognized flag: $x" >&2
    echo "use $0 --help for help" >&2
    exit 1
  fi
done

if [ "${STATIC}" ]; then
  LDFLAGS="-static ${LDFLAGS}"
  EXTRA_CFLAGS=-fno-pie
  EXTRA_LDFLAGS=-no-pie
  if config noop "checking for no-pie... "; then
    CFLAGS="-fno-pie ${CFLAGS}"
    LDFLAGS="-no-pie ${LDFLAGS}"
  fi
fi

# position independent executables
# 1. help ensure blink won't overlap static binaries in memory
# 2. gcc and clang generates tinier code for switch statements
EXTRA_CFLAGS=-fpie
EXTRA_LDFLAGS=-pie
if [ -z "${STATIC}" ] && config noop "checking for pie... "; then
  CFLAGS="-fpie ${CFLAGS}"
  LDFLAGS="-pie ${LDFLAGS}"
else
  # otherwise relocate blink somewhere irregular
  BASE=-Wl,--image-base=0x23000000
  EXTRA_LDFLAGS="${BASE}"
  if config noop "checking for ${BASE}... "; then
    LDFLAGS="${BASE} ${LDFLAGS}"
  else
    BASE=-Wl,-Ttext-segment=0x23000000
    EXTRA_LDFLAGS="${BASE}"
    if config noop "checking for ${BASE}... "; then
      LDFLAGS="${BASE} ${LDFLAGS}"
    fi
  fi
fi

# ensure binaries will run on apple m1, cygwin, etc.
# blink can't map a program into memory without this
GOODELF=-Wl,-z,common-page-size=65536,-z,max-page-size=65536
EXTRA_LDFLAGS="${GOODELF}"
if config noop "checking for ${GOODELF}..."; then
  LDFLAGS="${GOODELF} ${LDFLAGS}"
  # with 64kb pages these two security blankets would otherwise cause
  # blink's minimum binary size to increase from 120kb to 250kb. yuck
  NORELRO=-Wl,-z,norelro
  EXTRA_LDFLAGS="${NORELRO}"
  if config noop "checking for ${NORELRO}... "; then
    LDFLAGS="${NORELRO} ${LDFLAGS}"
  fi
  NORODATAPHDR=-Wl,-z,noseparate-code
  EXTRA_LDFLAGS="${NORODATAPHDR}"
  if config noop "checking for ${NORODATAPHDR}... "; then
    LDFLAGS="${NORODATAPHDR} ${LDFLAGS}"
  fi
fi

# check for the math library
EXTRA_LDLIBS=-lm
if config lm "checking for -lm... "; then
  LDLIBS="-lm ${LDLIBS}"
fi

# check for the posix threads library
if [ -z "${DISABLE_THREADS}" ]; then
  EXTRA_CFLAGS=-pthread
  EXTRA_LDFLAGS=-pthread
  if config pthread "checking for -pthread... "; then
    CFLAGS="-pthread ${CFLAGS}"
    LDFLAGS="-pthread ${LDFLAGS}"
  else
    EXTRA_LDLIBS=-lpthread
    if config pthread "checking for -lpthread... "; then
      LDLIBS="-lpthread ${LDLIBS}"
    else
      if config pthread "checking for pthreads... "; then
        LDLIBS="-lpthread ${LDLIBS}"
      else
        uncomment "#define DISABLE_THREADS"
      fi
    fi
  fi
fi

# check for the posix.1b realtime extensions library
# note: librt depends on pthreads, on rhel5 at least
EXTRA_LDLIBS=-lrt
if config lrt "checking for -lrt... "; then
  LDLIBS="-lrt ${LDLIBS}"
fi

# should be the default and macos build fails without it
EXTRA_CFLAGS=-fno-common
if config noop "checking for -fno-common... "; then
  CFLAGS="-fno-common ${CFLAGS}"
fi

# make sure sanitizers aren't enabled on micro-op functions
EXTRA_CFLAGS=-fno-sanitize=all
if config noop "checking for -fno-sanitize=all... "; then
  UOPFLAGS="-fno-sanitize=all ${UOPFLAGS}"
fi

# blink's jit will align the functions that matter
if [ -n "${JIT_POSSIBLE}" ] && [ -z "${DISABLE_JIT}" ]; then
  EXTRA_CFLAGS=-fno-align-functions
  if config noop "checking for -fno-align-functions... "; then
    CFLAGS="-fno-align-functions ${CFLAGS}"
  fi
fi

# blink's jit can't extract and relocate micro-op function bodies if the
# compiler inserts things like static memory references into them.
EXTRA_CFLAGS=-fno-stack-protector
if config noop "checking for -fno-stack-protector... "; then
  UOPFLAGS="-fno-stack-protector ${UOPFLAGS}"
fi

# avoid creating stack frames in micro-op functions
if [ "${MODE}" != "prof" ]; then
  EXTRA_CFLAGS=-fomit-frame-pointer
  if config noop "checking for -fomit-frame-pointer... "; then
    UOPFLAGS="${UOPFLAGS} -fomit-frame-pointer"
  fi
fi

# for everything else, stack frames are extremely important
if [ "${MODE}" != "tiny" ]; then
  EXTRA_CFLAGS=-fno-omit-frame-pointer
  if config noop "checking for -fno-omit-frame-pointer... "; then
    CFLAGS="${CFLAGS} -fno-omit-frame-pointer"
  fi
fi

# c11 atomics are no-op'd when both fork and threads are disabled
# this causes code to break modern compiler strict aliasing rules
# TODO(jart) is it safe to quash warning w/o -fno-strict-aliasing
if [ -n "${DISABLE_THREADS}" ] && [ -n "${DISABLE_FORK}" ]; then
  EXTRA_CFLAGS=-Wno-strict-aliasing
  if config noop "checking for -Wno-strict-aliasing... "; then
    CFLAGS="${CFLAGS} -Wno-strict-aliasing"
  fi
fi

# this optimization harms our ability to backtrace binaries
# blink doesn't rely on tail call optimization so we don't need it
if [ -z "${MODE}" ] && [ -n "${JIT_POSSIBLE}" ] && [ -z "${DISABLE_JIT}" ]; then
  EXTRA_CFLAGS=-fno-optimize-sibling-calls
  if config noop "checking for -fno-optimize-sibling-calls... "; then
    CFLAGS="${CFLAGS} -fno-optimize-sibling-calls"
  fi
fi

# use the system zlib if available
# otherwise, use our vendored copy
ZLIB_CFLAGS="$(pkg-config --cflags zlib 2>/dev/null)"
if ! ZLIB_LDLIBS="$(pkg-config --libs zlib 2>/dev/null)"; then
  ZLIB_LDLIBS="-lz"
fi
EXTRA_CFLAGS="${ZLIB_CFLAGS}"
EXTRA_LDLIBS="${ZLIB_LDLIBS}"
if config zlib "checking for zlib... "; then
  CFLAGS="${ZLIB_CFLAGS} ${CFLAGS}"
  LDLIBS="${ZLIB_LDLIBS} ${LDLIBS}"
  ZLIB=
else
  ZLIB='o/$(MODE)/third_party/libz/zlib.a'
fi

# try to get blink backtraces if possible
if [ "${MODE}" != "tiny" ] && [ "${MODE}" != "rel" ]; then
  UNWIND_CFLAGS="$(pkg-config --cflags libunwind 2>/dev/null)"
  if ! UNWIND_LDLIBS="$(pkg-config --libs libunwind 2>/dev/null)"; then
    UNWIND_LDLIBS="-lunwind -llzma"
  fi
  EXTRA_CFLAGS="${UNWIND_CFLAGS}"
  EXTRA_LDLIBS="${UNWIND_LDLIBS}"
  if config libunwind "checking for libunwind... "; then
    CFLAGS="${UNWIND_CFLAGS} ${CFLAGS}"
    LDLIBS="${UNWIND_LDLIBS} ${LDLIBS}"
    uncomment "#define HAVE_LIBUNWIND"
  fi
fi

# attempt to polyfill c11 atomics if it's not available
if ! config stdatomic "checking for stdatomic.h... "; then
  CPPFLAGS="-isystem tool/stdatomic ${CPPFLAGS}"
fi

if [ -z "${DISABLE_FORK}" ]; then
  ( config fork "checking for fork()... " uncomment "#define HAVE_FORK" ) &
else
  echo "checking for fork()... disabled"
fi

if [ -z "${POSIX}" ]; then
  ( config dup3 "checking for dup3()... " uncomment "#define HAVE_DUP3" ) &
  ( config pipe2 "checking for pipe2()... " uncomment "#define HAVE_PIPE2" ) &
  ( config getrandom "checking for getrandom()... " uncomment "#define HAVE_GETRANDOM" ) &
  ( config getentropy "checking for getentropy() in unistd.h... " uncomment "#define HAVE_GETENTROPY" ) &
  ( config dev_urandom "checking for /dev/urandom... " uncomment "#define HAVE_DEV_URANDOM" ) &
  ( config rtlgenrandom "checking for RtlGenRandom()... " uncomment "#define HAVE_RTLGENRANDOM" ) &
  ( config sys_getrandom "checking for syscall(SYS_getrandom)... " uncomment "#define HAVE_SYS_GETRANDOM" ) &
  ( config sys_getentropy "checking for getentropy() in sys/random.h... " uncomment "#define HAVE_SYS_GETENTROPY" ) &
  ( config getdomainname "checking for getdomainname()... " uncomment "#define HAVE_GETDOMAINNAME" ) &
  ( config kern_arnd "checking for sysctl(KERN_ARND)... " uncomment "#define HAVE_KERN_ARND" ) &
  ( config siocgifconf "checking for SIOCGIFCONF... " uncomment "#define HAVE_SIOCGIFCONF" ) &
  ( config epoll_pwait1 "checking for epoll_pwait()... " uncomment "#define HAVE_EPOLL_PWAIT1" ) &
  wait
  ( config epoll_pwait2 "checking for epoll_pwait2()... " uncomment "#define HAVE_EPOLL_PWAIT2" ) &
  ( config map_anonymous "checking for mmap(MAP_ANONYMOUS)... " uncomment "#define HAVE_MAP_ANONYMOUS" ) &
  ( config sched_getaffinity "checking for sched_getaffinity()... " uncomment "#define HAVE_SCHED_GETAFFINITY" ) &
  ( config scm_credentials "checking for SCM_CREDENTIALS... " uncomment "#define HAVE_SCM_CREDENTIALS" ) &
  ( config f_getown_ex "checking for F_GETOWN_EX... " uncomment "#define HAVE_F_GETOWN_EX" ) &
  ( config setgroups "checking for setgroups()... " uncomment "#define HAVE_SETGROUPS" ) &
  ( config vasprintf "checking for vasprintf()... " uncomment "#define HAVE_VASPRINTF" ) &
  ( config strchrnul "checking for strchrnul()... " uncomment "#define HAVE_STRCHRNUL" ) &
  ( config mkfifoat "checking for mkfifoat()... " uncomment "#define HAVE_MKFIFOAT" ) &
  ( config preadv "checking for preadv() and pwritev()... " uncomment "#define HAVE_PREADV" ) &
  ( config wait4 "checking for wait4()... " uncomment "#define HAVE_WAIT4" ) &
  ( config setresuid "checking for setresuid()... " uncomment "#define HAVE_SETRESUID" ) &
  ( config sys_mount_h "checking for sys/mount.h... " uncomment "#define HAVE_SYS_MOUNT_H" ) &
fi

( config sync "checking for sync()... " uncomment "#define HAVE_SYNC" ) &
( config sysctl "checking for sysctl()... " uncomment "#define HAVE_SYSCTL" ) &
( config sysinfo "checking for sysinfo()... " uncomment "#define HAVE_SYSINFO" ) &
( config fexecve "checking for fexecve()... " uncomment "#define HAVE_FEXECVE" ) &
( config wcwidth "checking for wcwidth()... " uncomment "#define HAVE_WCWIDTH" ) &
( config memccpy "checking for memccpy()... " uncomment "#define HAVE_MEMCCPY" ) &
( config seekdir "checking for seekdir()... " uncomment "#define HAVE_SEEKDIR" ) &
( config realpath "checking for realpath()... " uncomment "#define HAVE_REALPATH" ) &
( config setreuid "checking for setreuid()... " uncomment "#define HAVE_SETREUID" ) &
( config fdatasync "checking for fdatasync()... " uncomment "#define HAVE_FDATASYNC" ) &
( config sendto_zero "checking for sendto(0.0.0.0)... " uncomment "#define HAVE_SENDTO_ZERO" ) &
wait
( config struct_timezone "checking for struct timezone... " uncomment "#define HAVE_STRUCT_TIMEZONE" ) &
( config sa_len "checking for sockaddr::sa_len... " uncomment "#define HAVE_SA_LEN" ) &
( config map_shared "checking for mmap(MAP_SHARED)... " uncomment "#define HAVE_MAP_SHARED" ) &
( config sched_yield "checking for sched_yield()... " uncomment "#define HAVE_SCHED_YIELD" ) &
( config clock_settime "checking for clock_settime()... " uncomment "#define HAVE_CLOCK_SETTIME" ) &
( config sched_h "checking for sched.h... " uncomment "#define HAVE_SCHED_H" ) &
( config pthread_process_shared "checking for PTHREAD_PROCESS_SHARED... " uncomment "#define HAVE_PTHREAD_PROCESS_SHARED" ) &
( config pthread_setcancelstate "checking for pthread_setcancelstate()... " uncomment "#define HAVE_PTHREAD_SETCANCELSTATE" ) &
( config sockatmark "checking for sockatmark()... " uncomment "#define HAVE_SOCKATMARK" ) &

wait
rm -f "${LOCK}"

BLINK_UNAME_V=
if test "${DISABLE_NONPOSIX}"; then
  BLINK_UNAME_V="${BLINK_UNAME_V} POSIX"
fi
if test "${DISABLE_JIT}" || test -z "${JIT_POSSIBLE}"; then
  BLINK_UNAME_V="${BLINK_UNAME_V} NOJIT"
fi
if test "${DISABLE_SOCKETS}"; then
  BLINK_UNAME_V="${BLINK_UNAME_V} NOSOCK"
fi
if test -z "${BLINK_UNAME_V}"; then
  if test -z "$*"; then
    BLINK_UNAME_V="${BLINK_UNAME_V:-DEFAULT}"
  else
    BLINK_UNAME_V="${BLINK_UNAME_V:-CUSTOM}"
  fi
fi

for x; do
  if [ x"${x%=*}" != x"$x" ] && [ x"${x#--}" = x"$x" ]; then
    printf '%s\n' "$x" >>"${BUILD}"
  fi
done

cat >>"${BUILD}" <<EOF || exit
CC = ${CC}
AR = ${AR}
MODE ?= ${MODE}
TMPDIR = ${TMPDIR}
PREFIX = ${PREFIX}
CFLAGS = ${CFLAGS}
CPPFLAGS = ${CPPFLAGS}
UOPFLAGS = ${UOPFLAGS}
TARGET_ARCH = ${TARGET_ARCH}
LDFLAGS = ${LDFLAGS}
LDLIBS = ${LDLIBS}
HOST_OS = ${HOST_OS}
HOST_ARCH = ${HOST_ARCH}
HOST_SYSTEM = ${HOST_SYSTEM}
CONFIG_HOSTNAME = $(hostname)
CONFIG_COMMAND = ${CONFIG_COMMAND}
CONFIG_ARGUMENTS = -DCONFIG_ARGUMENTS="\"$*\""
BLINK_UNAME_V = -DBLINK_UNAME_V="\"$(echo ${BLINK_UNAME_V})\""
ZLIB = ${ZLIB}
EOF

echo "creating config.log" >&2

echo "creating config.mk" >&2
mv "${BUILD}" config.mk || exit

echo "creating config.h" >&2
mv "${CONFIG}" config.h || exit