configure

#!/bin/sh
#
# FFmpeg configure script
#
# Copyright (c) 2000-2002 Fabrice Bellard
# Copyright (c) 2005-2008 Diego Biurrun
# Copyright (c) 2005-2008 Mans Rullgard
#

# Prevent locale nonsense from breaking basic text processing.
LC_ALL=C
export LC_ALL

# make sure we are running under a compatible shell
# try to make this part work with most shells

try_exec(){
    echo "Trying shell $1"
    type "$1" > /dev/null 2>&1 && exec "$@"
}

unset foo
(: ${foo%%bar}) 2> /dev/null
E1="$?"

(: ${foo?}) 2> /dev/null
E2="$?"

if test "$E1" != 0 || test "$E2" = 0; then
    echo "Broken shell detected.  Trying alternatives."
    export FF_CONF_EXEC
    if test "0$FF_CONF_EXEC" -lt 1; then
        FF_CONF_EXEC=1
        try_exec bash "$0" "$@"
    fi
    if test "0$FF_CONF_EXEC" -lt 2; then
        FF_CONF_EXEC=2
        try_exec ksh "$0" "$@"
    fi
    if test "0$FF_CONF_EXEC" -lt 3; then
        FF_CONF_EXEC=3
        try_exec /usr/xpg4/bin/sh "$0" "$@"
    fi
    echo "No compatible shell script interpreter found."
    echo "This configure script requires a POSIX-compatible shell"
    echo "such as bash or ksh."
    echo "THIS IS NOT A BUG IN FFMPEG, DO NOT REPORT IT AS SUCH."
    echo "Instead, install a working POSIX-compatible shell."
    echo "Disabling this configure test will create a broken FFmpeg."
    if test "$BASH_VERSION" = '2.04.0(1)-release'; then
        echo "This bash version ($BASH_VERSION) is broken on your platform."
        echo "Upgrade to a later version if available."
    fi
    exit 1
fi

show_help(){
cat <<EOF
Usage: configure [options]
Options: [defaults in brackets after descriptions]

Help options:
  --help                   print this message
  --list-decoders          show all available decoders
  --list-encoders          show all available encoders
  --list-hwaccels          show all available hardware accelerators
  --list-demuxers          show all available demuxers
  --list-muxers            show all available muxers
  --list-parsers           show all available parsers
  --list-protocols         show all available protocols
  --list-bsfs              show all available bitstream filters
  --list-indevs            show all available input devices
  --list-outdevs           show all available output devices
  --list-filters           show all available filters

Standard options:
  --logfile=FILE           log tests and output to FILE [config.log]
  --disable-logging        do not log configure debug information
  --prefix=PREFIX          install in PREFIX [$prefix]
  --bindir=DIR             install binaries in DIR [PREFIX/bin]
  --datadir=DIR            install data files in DIR [PREFIX/share/ffmpeg]
  --libdir=DIR             install libs in DIR [PREFIX/lib]
  --shlibdir=DIR           install shared libs in DIR [PREFIX/lib]
  --incdir=DIR             install includes in DIR [PREFIX/include]
  --mandir=DIR             install man page in DIR [PREFIX/share/man]

Licensing options:
  --enable-gpl             allow use of GPL code, the resulting libs
                           and binaries will be under GPL [no]
  --enable-version3        upgrade (L)GPL to version 3 [no]
  --enable-nonfree         allow use of nonfree code, the resulting libs
                           and binaries will be unredistributable [no]

Configuration options:
  --disable-static         do not build static libraries [no]
  --enable-shared          build shared libraries [no]
  --enable-small           optimize for size instead of speed
  --enable-runtime-cpudetect detect cpu capabilities at runtime (bigger binary)
  --enable-gray            enable full grayscale support (slower color)
  --disable-swscale-alpha  disable alpha channel support in swscale

Component options:
  --disable-doc            do not build documentation
  --disable-ffmpeg         disable ffmpeg build
  --disable-ffplay         disable ffplay build
  --disable-ffprobe        disable ffprobe build
  --disable-ffserver       disable ffserver build
  --disable-avdevice       disable libavdevice build
  --disable-avcodec        disable libavcodec build
  --disable-avformat       disable libavformat build
  --disable-swresample     disable libswresample build
  --disable-swscale        disable libswscale build
  --disable-postproc       disable libpostproc build
  --disable-avfilter       disable libavfilter build
  --enable-avresample      enable libavresample build [no]
  --disable-pthreads       disable pthreads [auto]
  --disable-w32threads     disable Win32 threads [auto]
  --disable-os2threads     disable OS/2 threads [auto]
  --enable-x11grab         enable X11 grabbing [no]
  --disable-network        disable network support [no]
  --disable-dct            disable DCT code
  --disable-dwt            disable DWT code
  --disable-lsp            disable LSP code
  --disable-mdct           disable MDCT code
  --disable-rdft           disable RDFT code
  --disable-fft            disable FFT code
  --enable-dxva2           enable DXVA2 code
  --enable-vaapi           enable VAAPI code [autodetect]
  --enable-vda             enable VDA code   [autodetect]
  --enable-vdpau           enable VDPAU code [autodetect]

Individual component options:
  --disable-everything     disable all components listed below
  --disable-encoder=NAME   disable encoder NAME
  --enable-encoder=NAME    enable encoder NAME
  --disable-encoders       disable all encoders
  --disable-decoder=NAME   disable decoder NAME
  --enable-decoder=NAME    enable decoder NAME
  --disable-decoders       disable all decoders
  --disable-hwaccel=NAME   disable hwaccel NAME
  --enable-hwaccel=NAME    enable hwaccel NAME
  --disable-hwaccels       disable all hwaccels
  --disable-muxer=NAME     disable muxer NAME
  --enable-muxer=NAME      enable muxer NAME
  --disable-muxers         disable all muxers
  --disable-demuxer=NAME   disable demuxer NAME
  --enable-demuxer=NAME    enable demuxer NAME
  --disable-demuxers       disable all demuxers
  --enable-parser=NAME     enable parser NAME
  --disable-parser=NAME    disable parser NAME
  --disable-parsers        disable all parsers
  --enable-bsf=NAME        enable bitstream filter NAME
  --disable-bsf=NAME       disable bitstream filter NAME
  --disable-bsfs           disable all bitstream filters
  --enable-protocol=NAME   enable protocol NAME
  --disable-protocol=NAME  disable protocol NAME
  --disable-protocols      disable all protocols
  --enable-indev=NAME      enable input device NAME
  --disable-indev=NAME     disable input device NAME
  --disable-indevs         disable input devices
  --enable-outdev=NAME     enable output device NAME
  --disable-outdev=NAME    disable output device NAME
  --disable-outdevs        disable output devices
  --disable-devices        disable all devices
  --enable-filter=NAME     enable filter NAME
  --disable-filter=NAME    disable filter NAME
  --disable-filters        disable all filters

External library support:
  --enable-avisynth        enable reading of AVISynth script files [no]
  --enable-bzlib           enable bzlib [autodetect]
  --enable-fontconfig      enable fontconfig
  --enable-frei0r          enable frei0r video filtering
  --enable-gnutls          enable gnutls [no]
  --enable-libaacplus      enable AAC+ encoding via libaacplus [no]
  --enable-libass          enable libass subtitles rendering [no]
  --enable-libbluray       enable BluRay reading using libbluray [no]
  --enable-libcaca         enable textual display using libcaca
  --enable-libcelt         enable CELT decoding via libcelt [no]
  --enable-libcdio         enable audio CD grabbing with libcdio
  --enable-libdc1394       enable IIDC-1394 grabbing using libdc1394
                           and libraw1394 [no]
  --enable-libfaac         enable AAC encoding via libfaac [no]
  --enable-libfdk-aac      enable AAC encoding via libfdk-aac [no]
  --enable-libflite        enable flite (voice synthesis) support via libflite [no]
  --enable-libfreetype     enable libfreetype [no]
  --enable-libgsm          enable GSM de/encoding via libgsm [no]
  --enable-libiec61883     enable iec61883 via libiec61883 [no]
  --enable-libilbc         enable iLBC de/encoding via libilbc [no]
  --enable-libmodplug      enable ModPlug via libmodplug [no]
  --enable-libmp3lame      enable MP3 encoding via libmp3lame [no]
  --enable-libnut          enable NUT (de)muxing via libnut,
                           native (de)muxer exists [no]
  --enable-libopencore-amrnb enable AMR-NB de/encoding via libopencore-amrnb [no]
  --enable-libopencore-amrwb enable AMR-WB decoding via libopencore-amrwb [no]
  --enable-libopencv       enable video filtering via libopencv [no]
  --enable-libopenjpeg     enable JPEG 2000 de/encoding via OpenJPEG [no]
  --enable-libopus         enable Opus decoding via libopus [no]
  --enable-libpulse        enable Pulseaudio input via libpulse [no]
  --enable-librtmp         enable RTMP[E] support via librtmp [no]
  --enable-libschroedinger enable Dirac de/encoding via libschroedinger [no]
  --enable-libspeex        enable Speex de/encoding via libspeex [no]
  --enable-libstagefright-h264  enable H.264 decoding via libstagefright [no]
  --enable-libtheora       enable Theora encoding via libtheora [no]
  --enable-libutvideo      enable Ut Video encoding and decoding via libutvideo [no]
  --enable-libv4l2         enable libv4l2/v4l-utils [no]
  --enable-libvo-aacenc    enable AAC encoding via libvo-aacenc [no]
  --enable-libvo-amrwbenc  enable AMR-WB encoding via libvo-amrwbenc [no]
  --enable-libvorbis       enable Vorbis en/decoding via libvorbis,
                           native implementation exists [no]
  --enable-libvpx          enable VP8 de/encoding via libvpx [no]
  --enable-libx264         enable H.264 encoding via x264 [no]
  --enable-libxavs         enable AVS encoding via xavs [no]
  --enable-libxvid         enable Xvid encoding via xvidcore,
                           native MPEG-4/Xvid encoder exists [no]
  --enable-openal          enable OpenAL 1.1 capture support [no]
  --enable-openssl         enable openssl [no]
  --enable-zlib            enable zlib [autodetect]

Advanced options (experts only):
  --cross-prefix=PREFIX    use PREFIX for compilation tools [$cross_prefix]
  --enable-cross-compile   assume a cross-compiler is used
  --sysroot=PATH           root of cross-build tree
  --sysinclude=PATH        location of cross-build system headers
  --target-os=OS           compiler targets OS [$target_os]
  --target-exec=CMD        command to run executables on target
  --target-path=DIR        path to view of build directory on target
  --nm=NM                  use nm tool NM [$nm_default]
  --ar=AR                  use archive tool AR [$ar_default]
  --as=AS                  use assembler AS [$as_default]
  --yasmexe=EXE            use yasm-compatible assembler EXE [$yasmexe_default]
  --cc=CC                  use C compiler CC [$cc_default]
  --cxx=CXX                use C compiler CXX [$cxx_default]
  --dep-cc=DEPCC           use dependency generator DEPCC [$cc_default]
  --ld=LD                  use linker LD [$ld_default]
  --host-cc=HOSTCC         use host C compiler HOSTCC
  --host-cflags=HCFLAGS    use HCFLAGS when compiling for host
  --host-ldflags=HLDFLAGS  use HLDFLAGS when linking for host
  --host-libs=HLIBS        use libs HLIBS when linking for host
  --host-os=OS             compiler host OS [$target_os]
  --extra-cflags=ECFLAGS   add ECFLAGS to CFLAGS [$CFLAGS]
  --extra-cxxflags=ECFLAGS add ECFLAGS to CXXFLAGS [$CXXFLAGS]
  --extra-ldflags=ELDFLAGS add ELDFLAGS to LDFLAGS [$LDFLAGS]
  --extra-libs=ELIBS       add ELIBS [$ELIBS]
  --extra-version=STRING   version string suffix []
  --optflags=OPTFLAGS      override optimization-related compiler flags
  --build-suffix=SUFFIX    library name suffix []
  --malloc-prefix=PREFIX   prefix malloc and related names with PREFIX
  --progs-suffix=SUFFIX    program name suffix []
  --arch=ARCH              select architecture [$arch]
  --cpu=CPU                select the minimum required CPU (affects
                           instruction selection, may crash on older CPUs)
  --enable-pic             build position-independent code
  --enable-sram            allow use of on-chip SRAM
  --enable-thumb           compile for Thumb instruction set
  --disable-symver         disable symbol versioning
  --disable-fastdiv        disable table-based division
  --enable-hardcoded-tables use hardcoded tables instead of runtime generation
  --disable-safe-bitstream-reader
                           disable buffer boundary checking in bitreaders
                           (faster, but may crash)
  --enable-memalign-hack   emulate memalign, interferes with memory debuggers

Optimization options (experts only):
  --disable-asm            disable all assembler optimizations
  --disable-altivec        disable AltiVec optimizations
  --disable-amd3dnow       disable 3DNow! optimizations
  --disable-amd3dnowext    disable 3DNow! extended optimizations
  --disable-mmx            disable MMX optimizations
  --disable-mmxext         disable MMXEXT optimizations
  --disable-sse            disable SSE optimizations
  --disable-ssse3          disable SSSE3 optimizations
  --disable-avx            disable AVX optimizations
  --disable-fma4           disable FMA4 optimizations
  --disable-armv5te        disable armv5te optimizations
  --disable-armv6          disable armv6 optimizations
  --disable-armv6t2        disable armv6t2 optimizations
  --disable-armvfp         disable ARM VFP optimizations
  --disable-mmi            disable MMI optimizations
  --disable-neon           disable NEON optimizations
  --disable-vis            disable VIS optimizations
  --disable-yasm           disable use of yasm assembler
  --disable-mips32r2       disable MIPS32R2 optimizations
  --disable-mipsdspr1      disable MIPS DSP ASE R1 optimizations
  --disable-mipsdspr2      disable MIPS DSP ASE R2 optimizations
  --disable-mipsfpu        disable floating point MIPS optimizations
  --disable-fast-unaligned consider unaligned accesses slow
  --postproc-version=V     build libpostproc version V.
                           Where V can be '$ALT_PP_VER_MAJOR.$ALT_PP_VER_MINOR.$ALT_PP_VER_MICRO' or 'current'. [$postproc_version_default]

Developer options (useful when working on FFmpeg itself):
  --enable-coverage        build with test coverage instrumentation
  --disable-debug          disable debugging symbols
  --enable-debug=LEVEL     set the debug level [$debuglevel]
  --disable-optimizations  disable compiler optimizations
  --enable-extra-warnings  enable more compiler warnings
  --disable-stripping      disable stripping of executables and shared libraries
  --assert-level=level     0(default), 1 or 2, amount of assertion testing,
                           2 causes a slowdown at runtime.
  --enable-memory-poisoning fill heap uninitialized allocated space with arbitrary data
  --valgrind=VALGRIND      run "make fate" tests through valgrind to detect memory
                           leaks and errors, using the specified valgrind binary.
                           Cannot be combined with --target-exec
  --samples=PATH           location of test samples for FATE, if not set use
                           \$FATE_SAMPLES at make invocation time.
  --enable-xmm-clobber-test check XMM registers for clobbering (Win64-only;
                           should be used only for debugging purposes)
  --enable-random          randomly enable/disable components
  --disable-random
  --enable-random=LIST     randomly enable/disable specific components or
  --disable-random=LIST    component groups. LIST is a comma-separated list
                           of NAME[:PROB] entries where NAME is a component
                           (group) and PROB the probability associated with
                           NAME (default 0.5).
  --random-seed=VALUE      seed value for --enable/disable-random

NOTE: Object files are built at the place where configure is launched.
EOF
  exit 0
}

quotes='""'

log(){
    echo "$@" >> $logfile
}

log_file(){
    log BEGIN $1
    pr -n -t $1 >> $logfile
    log END $1
}

echolog(){
    log "$@"
    echo "$@"
}

warn(){
    log "WARNING: $*"
    WARNINGS="${WARNINGS}WARNING: $*\n"
}

die(){
    echolog "$@"
    cat <<EOF

If you think configure made a mistake, make sure you are using the latest
version from Git.  If the latest version fails, report the problem to the
ffmpeg-user@ffmpeg.org mailing list or IRC #ffmpeg on irc.freenode.net.
EOF
    if disabled logging; then
        cat <<EOF
Rerun configure with logging enabled (do not use --disable-logging), and
include the log this produces with your report.
EOF
    else
cat <<EOF
Include the log file "$logfile" produced by configure as this will help
solving the problem.
EOF
    fi
    exit 1
}

# Avoid locale weirdness, besides we really just want to translate ASCII.
toupper(){
    echo "$@" | tr abcdefghijklmnopqrstuvwxyz ABCDEFGHIJKLMNOPQRSTUVWXYZ
}

tolower(){
    echo "$@" | tr ABCDEFGHIJKLMNOPQRSTUVWXYZ abcdefghijklmnopqrstuvwxyz
}

c_escape(){
    echo "$*" | sed 's/["\\]/\\\0/g'
}

sh_quote(){
    v=$(echo "$1" | sed "s/'/'\\\\''/g")
    test "x$v" = "x${v#*[!A-Za-z0-9_/.+-]}" || v="'$v'"
    echo "$v"
}

cleanws(){
    echo "$@" | sed 's/^ *//;s/  */ /g;s/ *$//'
}

filter(){
    pat=$1
    shift
    for v; do
        eval "case $v in $pat) echo $v ;; esac"
    done
}

filter_out(){
    pat=$1
    shift
    for v; do
        eval "case $v in $pat) ;; *) echo $v ;; esac"
    done
}

map(){
    m=$1
    shift
    for v; do eval $m; done
}

set_all(){
    value=$1
    shift
    for var in $*; do
        eval $var=$value
    done
}

set_weak(){
    value=$1
    shift
    for var; do
        eval : \${$var:=$value}
    done
}

set_safe(){
    var=$1
    shift
    eval $(echo "$var" | sed 's/[^A-Za-z0-9_]/_/g')='$*'
}

get_safe(){
    eval echo \$$(echo "$1" | sed 's/[^A-Za-z0-9_]/_/g')
}

pushvar(){
    for var in $*; do
        eval level=\${${var}_level:=0}
        eval ${var}_${level}="\$$var"
        eval ${var}_level=$(($level+1))
    done
}

popvar(){
    for var in $*; do
        eval level=\${${var}_level:-0}
        test $level = 0 && continue
        eval level=$(($level-1))
        eval $var="\${${var}_${level}}"
        eval ${var}_level=$level
        eval unset ${var}_${level}
    done
}

enable(){
    set_all yes $*
}

disable(){
    set_all no $*
}

enable_weak(){
    set_weak yes $*
}

disable_weak(){
    set_weak no $*
}

enable_safe(){
    for var; do
        enable $(echo "$var" | sed 's/[^A-Za-z0-9_]/_/g')
    done
}

disable_safe(){
    for var; do
        disable $(echo "$var" | sed 's/[^A-Za-z0-9_]/_/g')
    done
}

do_enable_deep(){
    for var; do
        enabled $var && continue
        eval sel="\$${var}_select"
        eval sgs="\$${var}_suggest"
        pushvar var sgs
        enable_deep $sel
        popvar sgs
        enable_deep_weak $sgs
        popvar var
    done
}

enable_deep(){
    do_enable_deep $*
    enable $*
}

enable_deep_weak(){
    do_enable_deep $*
    enable_weak $*
}

enabled(){
    test "${1#!}" = "$1" && op== || op=!=
    eval test "x\$${1#!}" $op "xyes"
}

disabled(){
    test "${1#!}" = "$1" && op== || op=!=
    eval test "x\$${1#!}" $op "xno"
}

enabled_all(){
    for opt; do
        enabled $opt || return 1
    done
}

disabled_all(){
    for opt; do
        disabled $opt || return 1
    done
}

enabled_any(){
    for opt; do
        enabled $opt && return 0
    done
}

disabled_any(){
    for opt; do
        disabled $opt && return 0
    done
    return 1
}

set_default(){
    for opt; do
        eval : \${$opt:=\$${opt}_default}
    done
}

is_in(){
    value=$1
    shift
    for var in $*; do
        [ $var = $value ] && return 0
    done
    return 1
}

check_deps(){
    for cfg; do
        cfg="${cfg#!}"
        enabled ${cfg}_checking && die "Circular dependency for $cfg."
        disabled ${cfg}_checking && continue
        enable ${cfg}_checking

        eval dep_all="\$${cfg}_deps"
        eval dep_any="\$${cfg}_deps_any"
        eval dep_sel="\$${cfg}_select"
        eval dep_sgs="\$${cfg}_suggest"
        eval dep_ifa="\$${cfg}_if"
        eval dep_ifn="\$${cfg}_if_any"

        pushvar cfg dep_all dep_any dep_sel dep_sgs dep_ifa dep_ifn
        check_deps $dep_all $dep_any $dep_sel $dep_sgs $dep_ifa $dep_ifn
        popvar cfg dep_all dep_any dep_sel dep_sgs dep_ifa dep_ifn

        [ -n "$dep_ifa" ] && { enabled_all $dep_ifa && enable_weak $cfg; }
        [ -n "$dep_ifn" ] && { enabled_any $dep_ifn && enable_weak $cfg; }
        enabled_all  $dep_all || disable $cfg
        enabled_any  $dep_any || disable $cfg
        disabled_any $dep_sel && disable $cfg

        if enabled $cfg; then
            eval dep_extralibs="\$${cfg}_extralibs"
            test -n "$dep_extralibs" && add_extralibs $dep_extralibs
            enable_deep $dep_sel
            enable_deep_weak $dep_sgs
        fi

        disable ${cfg}_checking
    done
}

print_config_h(){
    enabled $1 && v=1 || v=0
    echo "#define $2 $v"
}

print_config_mak(){
    enabled $1 && v= || v=!
    echo "$v$2=yes"
}

print_config_asm(){
    enabled $1 && v=1 || v=0
    echo "%define $2 $v"
}

print_config(){
    pfx=$1
    files=$2
    shift 2
    for cfg; do
        ucname="$(toupper $cfg)"
        for f in $files; do
            "print_config_${f##*.}" $cfg ${pfx}${ucname} >>$f
        done
    done
}

print_enabled(){
    test "$1" = -n && end=" " && shift || end="\n"
    suf=$1
    shift
    for v; do
        enabled $v && printf "%s$end" ${v%$suf};
    done
}

append(){
    var=$1
    shift
    eval "$var=\"\$$var $*\""
}

prepend(){
    var=$1
    shift
    eval "$var=\"$* \$$var\""
}

add_cppflags(){
    append CPPFLAGS "$@"
}

add_cflags(){
    append CFLAGS $($cflags_filter "$@")
}

add_cxxflags(){
    append CXXFLAGS $($cflags_filter "$@")
}

add_asflags(){
    append ASFLAGS $($asflags_filter "$@")
}

add_ldflags(){
    append LDFLAGS $($ldflags_filter "$@")
}

add_extralibs(){
    prepend extralibs $($ldflags_filter "$@")
}

add_host_cflags(){
    append host_cflags $($host_cflags_filter "$@")
}

add_host_ldflags(){
    append host_ldflags $($host_ldflags_filter "$@")
}

check_cmd(){
    log "$@"
    "$@" >> $logfile 2>&1
}

cc_o(){
    eval printf '%s\\n' $CC_O
}

cc_e(){
    eval printf '%s\\n' $CC_E
}

check_cc(){
    log check_cc "$@"
    cat > $TMPC
    log_file $TMPC
    check_cmd $cc $CPPFLAGS $CFLAGS "$@" $CC_C $(cc_o $TMPO) $TMPC
}

check_cxx(){
    log check_cxx "$@"
    cat > $TMPCPP
    log_file $TMPCPP
    check_cmd $cxx $CPPFLAGS $CFLAGS $CXXFLAGS "$@" $CXX_C -o $TMPO $TMPCPP
}

check_cpp(){
    log check_cpp "$@"
    cat > $TMPC
    log_file $TMPC
    check_cmd $cc $CPPFLAGS $CFLAGS "$@" $(cc_e $TMPO) $TMPC
}

check_as(){
    log check_as "$@"
    cat > $TMPC
    log_file $TMPC
    check_cmd $as $CPPFLAGS $ASFLAGS "$@" $AS_C -o $TMPO $TMPC
}

check_asm(){
    log check_asm "$@"
    name="$1"
    code="$2"
    shift 2
    disable $name
    check_as "$@" <<EOF && enable $name
void foo(void){ __asm__ volatile($code); }
EOF
}

check_yasm(){
    log check_yasm "$@"
    echo "$1" > $TMPS
    log_file $TMPS
    shift 1
    check_cmd $yasmexe $YASMFLAGS "$@" -o $TMPO $TMPS
}

check_ld(){
    log check_ld "$@"
    type=$1
    shift 1
    flags=''
    libs=''
    for f; do
        test "${f}" = "${f#-l}" && flags="$flags $f" || libs="$libs $f"
    done
    check_$type $($cflags_filter $flags) || return
    flags=$($ldflags_filter $flags)
    libs=$($ldflags_filter $libs)
    check_cmd $ld $LDFLAGS $flags -o $TMPE $TMPO $libs $extralibs
}

check_code(){
    log check_code "$@"
    check=$1
    headers=$2
    code=$3
    shift 3
    {
        for hdr in $headers; do
            echo "#include <$hdr>"
        done
        echo "int main(void) { $code; return 0; }"
    } | check_$check "$@"
}

check_cppflags(){
    log check_cppflags "$@"
    check_cc "$@" <<EOF && append CPPFLAGS "$@"
int x;
EOF
}

check_cflags(){
    log check_cflags "$@"
    set -- $($cflags_filter "$@")
    check_cc "$@" <<EOF && append CFLAGS "$@"
int x;
EOF
}

check_cxxflags(){
    log check_cxxflags "$@"
    set -- $($cflags_filter "$@")
    check_cxx "$@" <<EOF && append CXXFLAGS "$@"
int x;
EOF
}

test_ldflags(){
    log test_ldflags "$@"
    check_ld "cc" "$@" <<EOF
int main(void){ return 0; }
EOF
}

check_ldflags(){
    log check_ldflags "$@"
    test_ldflags "$@" && add_ldflags "$@"
}

check_header(){
    log check_header "$@"
    header=$1
    shift
    disable_safe $header
    check_cpp "$@" <<EOF && enable_safe $header
#include <$header>
int x;
EOF
}

check_func(){
    log check_func "$@"
    func=$1
    shift
    disable $func
    check_ld "cc" "$@" <<EOF && enable $func
extern int $func();
int main(void){ $func(); }
EOF
}

check_mathfunc(){
    log check_mathfunc "$@"
    func=$1
    shift
    disable $func
    check_ld "cc" "$@" <<EOF && enable $func
#include <math.h>
float foo(float f) { return $func(f); }
int main(void){ return (int) foo; }
EOF
}

check_func_headers(){
    log check_func_headers "$@"
    headers=$1
    funcs=$2
    shift 2
    {
        for hdr in $headers; do
            echo "#include <$hdr>"
        done
        for func in $funcs; do
            echo "long check_$func(void) { return (long) $func; }"
        done
        echo "int main(void) { return 0; }"
    } | check_ld "cc" "$@" && enable $funcs && enable_safe $headers
}

check_class_headers_cpp(){
    log check_class_headers_cpp "$@"
    headers=$1
    classes=$2
    shift 2
    {
        for hdr in $headers; do
            echo "#include <$hdr>"
        done
        echo "int main(void) { "
        i=1
        for class in $classes; do
            echo "$class obj$i;"
            i=$(expr $i + 1)
        done
        echo "return 0; }"
    } | check_ld "cxx" "$@" && enable $funcs && enable_safe $headers
}

check_cpp_condition(){
    log check_cpp_condition "$@"
    header=$1
    condition=$2
    shift 2
    check_cpp "$@" <<EOF
#include <$header>
#if !($condition)
#error "unsatisfied condition: $condition"
#endif
EOF
}

check_lib(){
    log check_lib "$@"
    header="$1"
    func="$2"
    shift 2
    check_header $header && check_func $func "$@" && add_extralibs "$@"
}

check_lib2(){
    log check_lib2 "$@"
    headers="$1"
    funcs="$2"
    shift 2
    check_func_headers "$headers" "$funcs" "$@" && add_extralibs "$@"
}

check_lib_cpp(){
    log check_lib_cpp "$@"
    headers="$1"
    classes="$2"
    shift 2
    check_class_headers_cpp "$headers" "$classes" "$@" && add_extralibs "$@"
}

check_pkg_config(){
    log check_pkg_config "$@"
    pkg="$1"
    headers="$2"
    funcs="$3"
    shift 3
    $pkg_config --exists $pkg 2>/dev/null || return
    pkg_cflags=$($pkg_config --cflags $pkg)
    pkg_libs=$($pkg_config --libs $pkg)
    check_func_headers "$headers" "$funcs" $pkg_cflags $pkg_libs "$@" &&
        set_safe ${pkg}_cflags $pkg_cflags   &&
        set_safe ${pkg}_libs   $pkg_libs
}

check_exec(){
    check_ld "cc" "$@" && { enabled cross_compile || $TMPE >> $logfile 2>&1; }
}

check_exec_crash(){
    code=$(cat)

    # exit() is not async signal safe.  _Exit (C99) and _exit (POSIX)
    # are safe but may not be available everywhere.  Thus we use
    # raise(SIGTERM) instead.  The check is run in a subshell so we
    # can redirect the "Terminated" message from the shell.  SIGBUS
    # is not defined by standard C so it is used conditionally.

    (check_exec "$@") >> $logfile 2>&1 <<EOF
#include <signal.h>
static void sighandler(int sig){
    raise(SIGTERM);
}
int func(void){
    $code
}
int (*func_ptr)(void) = func;
int main(void){
    signal(SIGILL, sighandler);
    signal(SIGFPE, sighandler);
    signal(SIGSEGV, sighandler);
#ifdef SIGBUS
    signal(SIGBUS, sighandler);
#endif
    return func_ptr();
}
EOF
}

check_type(){
    log check_type "$@"
    headers=$1
    type=$2
    shift 2
    disable_safe "$type"
    check_code cc "$headers" "$type v" "$@" && enable_safe "$type"
}

check_struct(){
    log check_type "$@"
    headers=$1
    struct=$2
    member=$3
    shift 3
    disable_safe "${struct}_${member}"
    check_code cc "$headers" "const void *p = &(($struct *)0)->$member" "$@" &&
        enable_safe "${struct}_${member}"
}

require(){
    name="$1"
    header="$2"
    func="$3"
    shift 3
    check_lib $header $func "$@" || die "ERROR: $name not found"
}

require2(){
    name="$1"
    headers="$2"
    func="$3"
    shift 3
    check_lib2 "$headers" $func "$@" || die "ERROR: $name not found"
}

require_cpp(){
    name="$1"
    headers="$2"
    classes="$3"
    shift 3
    check_lib_cpp "$headers" "$classes" "$@" || die "ERROR: $name not found"
}

require_pkg_config(){
    pkg="$1"
    check_pkg_config "$@" || die "ERROR: $pkg not found"
    add_cflags    $(get_safe ${pkg}_cflags)
    add_extralibs $(get_safe ${pkg}_libs)
}