configure

if enabled aarch64; then
    enabled armv8 && check_insn armv8 'prfm   pldl1strm, [x0]'
    # internal assembler in clang 3.3 does not support this instruction
    enabled neon && check_insn neon 'ext   v0.8B, v0.8B, v1.8B, #1'
    enabled vfp  && check_insn vfp  'fmadd d0,    d0,    d1,    d2'

    map 'enabled_any ${v}_external ${v}_inline || disable $v' $ARCH_EXT_LIST_ARM

elif enabled alpha; then

    check_cflags -mieee

elif enabled arm; then

    enabled msvc && check_cpp_condition stddef.h "defined _M_ARMT" && enable thumb

    check_cpp_condition stddef.h "defined __thumb__" && check_cc <<EOF && enable_weak thumb
float func(float a, float b){ return a+b; }
EOF

    enabled thumb && check_cflags -mthumb || check_cflags -marm

    if     check_cpp_condition stddef.h "defined __ARM_PCS_VFP"; then
        enable vfp_args
    elif check_cpp_condition stddef.h "defined _M_ARM_FP && _M_ARM_FP >= 30"; then
        enable vfp_args
    elif ! check_cpp_condition stddef.h "defined __ARM_PCS || defined __SOFTFP__" && [ $target_os != darwin ]; then
        case "${cross_prefix:-$cc}" in
            *hardfloat*)         enable vfp_args;   fpabi=vfp ;;
            *) check_ld "cc" <<EOF && enable vfp_args && fpabi=vfp || fpabi=soft ;;
__asm__ (".eabi_attribute 28, 1");
int main(void) { return 0; }
EOF
        esac
        warn "Compiler does not indicate floating-point ABI, guessing $fpabi."
    fi

    enabled armv5te && check_insn armv5te 'qadd r0, r0, r0'
    enabled armv6   && check_insn armv6   'sadd16 r0, r0, r0'
    enabled armv6t2 && check_insn armv6t2 'movt r0, #0'
    enabled neon    && check_insn neon    'vadd.i16 q0, q0, q0'
    enabled vfp     && check_insn vfp     'fadds s0, s0, s0'
    enabled vfpv3   && check_insn vfpv3   'vmov.f32 s0, #1.0'
    enabled setend  && check_insn setend  'setend be'

    [ $target_os = linux ] || [ $target_os = android ] ||
        map 'enabled_any ${v}_external ${v}_inline || disable $v' \
            $ARCH_EXT_LIST_ARM

    check_inline_asm asm_mod_q '"add r0, %Q0, %R0" :: "r"((long long)0)'

    check_as <<EOF && enable as_dn_directive
ra .dn d0.i16
.unreq ra
EOF

    # llvm's integrated assembler supports .object_arch from llvm 3.5
    [ "$objformat" = elf ] && check_as <<EOF && enable as_object_arch
.object_arch armv4
EOF

    [ $target_os != win32 ] && enabled_all armv6t2 shared !pic && enable_weak_pic

elif enabled mips; then

    enabled loongson2 && check_inline_asm loongson2 '"dmult.g $8, $9, $10"'
    enabled loongson3 && check_inline_asm loongson3 '"gsldxc1 $f0, 0($2, $3)"'
    enabled mmi && check_inline_asm mmi '"punpcklhw $f0, $f0, $f0"'

    # Enable minimum ISA based on selected options
    if enabled mips64 && (enabled mipsdsp || enabled mipsdspr2); then
        add_cflags "-mips64r2"
        add_asflags "-mips64r2"
    elif enabled mips64 && enabled mipsfpu && disabled loongson2 && disabled loongson3; then
        add_cflags "-mips64"
        add_asflags "-mips64"
    elif enabled mipsdsp || enabled mipsdspr2; then
        add_cflags "-mips32r2 -mfp32"
        add_asflags "-mips32r2 -mfp32"
    fi

    enabled mipsdsp && add_cflags "-mdsp" && add_asflags "-mdsp" &&
     check_inline_asm mipsdsp '"addu.qb $t0, $t1, $t2"'
    enabled mipsdspr2 && add_cflags "-mdspr2" && add_asflags "-mdspr2" &&
     check_inline_asm mipsdspr2 '"absq_s.qb $t0, $t1"'
    enabled mipsfpu   && add_cflags "-mhard-float" && add_asflags "-mhard-float" &&
     check_inline_asm mipsfpu   '"madd.d $f0, $f2, $f4, $f6"'
    enabled msa       && check_cflags "-mmsa" && check_ldflags "-mmsa" &&
     check_inline_asm msa       '"addvi.b $w0, $w1, 1"'

    enabled msa && add_asflags "-mmsa"

elif enabled parisc; then

    if enabled gcc; then
        case $($cc -dumpversion) in
            4.[3-9].*) check_cflags -fno-optimize-sibling-calls ;;
        esac
    fi

elif enabled ppc; then

    enable local_aligned_8 local_aligned_16 local_aligned_32

    check_inline_asm dcbzl     '"dcbzl 0, %0" :: "r"(0)'
    check_inline_asm ibm_asm   '"add 0, 0, 0"'
    check_inline_asm ppc4xx    '"maclhw r10, r11, r12"'
    check_inline_asm xform_asm '"lwzx %1, %y0" :: "Z"(*(int*)0), "r"(0)'

    # AltiVec flags: The FSF version of GCC differs from the Apple version
    if enabled altivec; then
        check_cflags -maltivec -mabi=altivec &&
        { check_header altivec.h && inc_altivec_h="#include <altivec.h>" ; } ||
        check_cflags -faltivec

        # check if our compiler supports Motorola AltiVec C API
        check_cc <<EOF || disable altivec
$inc_altivec_h
int main(void) {
    vector signed int v1 = (vector signed int) { 0 };
    vector signed int v2 = (vector signed int) { 1 };
    v1 = vec_add(v1, v2);
    return 0;
}
EOF

        enabled altivec || warn "Altivec disabled, possibly missing --cpu flag"
    fi

    if enabled vsx; then
        check_cflags -mvsx &&
        check_builtin vec_vsx_ld "altivec.h" "__builtin_vec_vsx_ld" || disable vsx
    fi

    if enabled power8; then
        check_cpp_condition "altivec.h" "defined(_ARCH_PWR8)" || disable power8
    fi

elif enabled x86; then

    check_builtin rdtsc    intrin.h   "__rdtsc()"
    check_builtin mm_empty mmintrin.h "_mm_empty()"

    enable local_aligned_8 local_aligned_16 local_aligned_32

    # check whether EBP is available on x86
    # As 'i' is stored on the stack, this program will crash
    # if the base pointer is used to access it because the
    # base pointer is cleared in the inline assembly code.
    check_exec_crash <<EOF && enable ebp_available
volatile int i=0;
__asm__ volatile ("xorl %%ebp, %%ebp" ::: "%ebp");
return i;
EOF

    # check whether EBX is available on x86
    check_inline_asm ebx_available '""::"b"(0)' &&
        check_inline_asm ebx_available '"":::"%ebx"'

    # check whether xmm clobbers are supported
    check_inline_asm xmm_clobbers '"":::"%xmm0"'

    check_inline_asm inline_asm_direct_symbol_refs '"movl '$extern_prefix'test, %eax"' ||
        check_inline_asm inline_asm_direct_symbol_refs '"movl '$extern_prefix'test(%rip), %eax"'

    # check whether binutils is new enough to compile SSSE3/MMXEXT
    enabled ssse3  && check_inline_asm ssse3_inline  '"pabsw %xmm0, %xmm0"'
    enabled mmxext && check_inline_asm mmxext_inline '"pmaxub %mm0, %mm1"'

    if ! disabled_any asm mmx yasm; then
        if check_cmd $yasmexe --version; then
            enabled x86_64 && yasm_extra="-m amd64"
            yasm_debug="-g dwarf2"
        elif check_cmd nasm -v; then
            yasmexe=nasm
            yasm_debug="-g -F dwarf"
            if enabled x86_64; then
                case "$objformat" in
                    elf)   objformat=elf64 ;;
                    win32) objformat=win64 ;;
                esac
            fi
        fi

        YASMFLAGS="-f $objformat $yasm_extra"
        enabled pic               && append YASMFLAGS "-DPIC"
        test -n "$extern_prefix"  && append YASMFLAGS "-DPREFIX"
        case "$objformat" in
            elf*) enabled debug && append YASMFLAGS $yasm_debug ;;
        esac

        check_yasm "movbe ecx, [5]" && enable yasm ||
            die "yasm/nasm not found or too old. Use --disable-yasm for a crippled build."
        check_yasm "vextracti128 xmm0, ymm0, 0"      || disable avx2_external
        check_yasm "vpmacsdd xmm0, xmm1, xmm2, xmm3" || disable xop_external
        check_yasm "vfmaddps ymm0, ymm1, ymm2, ymm3" || disable fma4_external
        check_yasm "CPU amdnop" || disable cpunop
    fi

    case "$cpu" in
        athlon*|opteron*|k8*|pentium|pentium-mmx|prescott|nocona|atom|geode)
            disable fast_clz
        ;;
    esac

fi

check_code cc arm_neon.h "int16x8_t test = vdupq_n_s16(0)" && enable intrinsics_neon

check_ldflags -Wl,--as-needed
check_ldflags -Wl,-z,noexecstack

if check_func dlopen; then
    ldl=
elif check_func dlopen -ldl; then
    ldl=-ldl
fi

frei0r_filter_extralibs='$ldl'
frei0r_src_filter_extralibs='$ldl'
ladspa_filter_extralibs='$ldl'
nvenc_encoder_extralibs='$ldl'

if ! disabled network; then
    check_func getaddrinfo $network_extralibs
    check_func inet_aton $network_extralibs

    check_type netdb.h "struct addrinfo"
    check_type netinet/in.h "struct group_source_req" -D_BSD_SOURCE
    check_type netinet/in.h "struct ip_mreq_source" -D_BSD_SOURCE
    check_type netinet/in.h "struct ipv6_mreq" -D_DARWIN_C_SOURCE
    check_type poll.h "struct pollfd"
    check_type netinet/sctp.h "struct sctp_event_subscribe"
    check_struct "sys/types.h sys/socket.h" "struct sockaddr" sa_len
    check_type netinet/in.h "struct sockaddr_in6"
    check_type "sys/types.h sys/socket.h" "struct sockaddr_storage"
    check_type "sys/types.h sys/socket.h" socklen_t

    # Prefer arpa/inet.h over winsock2
    if check_header arpa/inet.h ; then
        check_func closesocket
    elif check_header winsock2.h ; then
        check_func_headers winsock2.h closesocket -lws2 &&
            network_extralibs="-lws2" ||
        { check_func_headers winsock2.h closesocket -lws2_32 &&
            network_extralibs="-lws2_32"; } || disable winsock2_h network
        check_func_headers ws2tcpip.h getaddrinfo $network_extralibs

        check_type ws2tcpip.h socklen_t
        check_type ws2tcpip.h "struct addrinfo"
        check_type ws2tcpip.h "struct group_source_req"
        check_type ws2tcpip.h "struct ip_mreq_source"
        check_type ws2tcpip.h "struct ipv6_mreq"
        check_type winsock2.h "struct pollfd"
        check_struct winsock2.h "struct sockaddr" sa_len
        check_type ws2tcpip.h "struct sockaddr_in6"
        check_type ws2tcpip.h "struct sockaddr_storage"
    else
        disable network
    fi
fi

check_builtin atomic_cas_ptr atomic.h "void **ptr; void *oldval, *newval; atomic_cas_ptr(ptr, oldval, newval)"
check_builtin atomic_compare_exchange "" "int *ptr, *oldval; int newval; __atomic_compare_exchange_n(ptr, oldval, newval, 0, __ATOMIC_SEQ_CST, __ATOMIC_SEQ_CST)"
check_builtin machine_rw_barrier mbarrier.h "__machine_rw_barrier()"
check_builtin MemoryBarrier windows.h "MemoryBarrier()"
check_builtin sarestart signal.h "SA_RESTART"
check_builtin sync_val_compare_and_swap "" "int *ptr; int oldval, newval; __sync_val_compare_and_swap(ptr, oldval, newval)"
check_builtin gmtime_r time.h "time_t *time; struct tm *tm; gmtime_r(time, tm)"
check_builtin localtime_r time.h "time_t *time; struct tm *tm; localtime_r(time, tm)"

case "$custom_allocator" in
    jemalloc)
        # jemalloc by default does not use a prefix
        require libjemalloc jemalloc/jemalloc.h malloc -ljemalloc
    ;;
    tcmalloc)
        require_pkg_config libtcmalloc gperftools/tcmalloc.h tc_malloc
        malloc_prefix=tc_
    ;;
esac

check_func_headers malloc.h _aligned_malloc     && enable aligned_malloc
check_func  ${malloc_prefix}memalign            && enable memalign
check_func  ${malloc_prefix}posix_memalign      && enable posix_memalign

check_func  access
check_func  arc4random
check_func_headers time.h clock_gettime || { check_func_headers time.h clock_gettime -lrt && add_extralibs -lrt && LIBRT="-lrt"; }
check_func  fcntl
check_func  fork
check_func  gethrtime
check_func  getopt
check_func  getrusage
check_func  gettimeofday
check_func  isatty
check_func  mach_absolute_time
check_func  mkstemp
check_func  mmap
check_func  mprotect
# Solaris has nanosleep in -lrt, OpenSolaris no longer needs that
check_func_headers time.h nanosleep || { check_func_headers time.h nanosleep -lrt && add_extralibs -lrt && LIBRT="-lrt"; }
check_func  sched_getaffinity
check_func  setrlimit
check_struct "sys/stat.h" "struct stat" st_mtim.tv_nsec -D_BSD_SOURCE
check_func  strerror_r
check_func  sysconf
check_func  sysctl
check_func  usleep

check_func_headers conio.h kbhit
check_func_headers io.h setmode
check_func_headers lzo/lzo1x.h lzo1x_999_compress
check_func_headers stdlib.h getenv
check_func_headers sys/stat.h lstat

check_func_headers windows.h CoTaskMemFree -lole32
check_func_headers windows.h GetProcessAffinityMask
check_func_headers windows.h GetProcessTimes
check_func_headers windows.h GetSystemTimeAsFileTime
check_func_headers windows.h MapViewOfFile
check_func_headers windows.h PeekNamedPipe
check_func_headers windows.h SetConsoleTextAttribute
check_func_headers windows.h SetConsoleCtrlHandler
check_func_headers windows.h Sleep
check_func_headers windows.h VirtualAlloc
check_struct windows.h "CONDITION_VARIABLE" Ptr
check_func_headers glob.h glob
enabled xlib &&
    check_func_headers "X11/Xlib.h X11/extensions/Xvlib.h" XvGetPortAttribute -lXv -lX11 -lXext

check_header direct.h
check_header dirent.h
check_header dlfcn.h
check_header d3d11.h
check_header dxva.h
check_header dxva2api.h -D_WIN32_WINNT=0x0600
check_header io.h
check_header libcrystalhd/libcrystalhd_if.h
check_header mach/mach_time.h
check_header malloc.h
check_header net/udplite.h
check_header poll.h
check_header sys/mman.h
check_header sys/param.h
check_header sys/resource.h
check_header sys/select.h
check_header sys/time.h
check_header sys/un.h
check_header termios.h
check_header unistd.h
check_header valgrind/valgrind.h
check_header vdpau/vdpau.h
check_header vdpau/vdpau_x11.h
check_header VideoDecodeAcceleration/VDADecoder.h
check_header VideoToolbox/VideoToolbox.h
check_header windows.h
check_header X11/extensions/XvMClib.h
check_header asm/types.h

check_lib2 "windows.h shellapi.h" CommandLineToArgvW -lshell32
check_lib2 "windows.h wincrypt.h" CryptGenRandom -ladvapi32
check_lib2 "windows.h psapi.h" GetProcessMemoryInfo -lpsapi
check_lib "CoreServices/CoreServices.h" UTGetOSTypeFromString "-framework CoreServices"

check_struct "sys/time.h sys/resource.h" "struct rusage" ru_maxrss

check_type "windows.h dxva.h" "DXVA_PicParams_HEVC" -DWINAPI_FAMILY=WINAPI_FAMILY_DESKTOP_APP -D_CRT_BUILD_DESKTOP_APP=0
check_type "windows.h dxva.h" "DXVA_PicParams_VP9" -DWINAPI_FAMILY=WINAPI_FAMILY_DESKTOP_APP -D_CRT_BUILD_DESKTOP_APP=0
check_type "windows.h d3d11.h" "ID3D11VideoDecoder"
check_type "windows.h d3d11.h" "ID3D11VideoContext"
check_type "d3d9.h dxva2api.h" DXVA2_ConfigPictureDecode -D_WIN32_WINNT=0x0602

check_type "va/va.h" "VAPictureParameterBufferHEVC"
check_type "va/va.h" "VADecPictureParameterBufferVP9"

check_type "vdpau/vdpau.h" "VdpPictureInfoHEVC"

check_cpp_condition windows.h "!WINAPI_FAMILY_PARTITION(WINAPI_PARTITION_DESKTOP)" && enable winrt || disable winrt

if ! disabled w32threads && ! enabled pthreads; then
    check_func_headers "windows.h process.h" _beginthreadex &&
        enable w32threads || disable w32threads
    if ! enabled w32threads && enabled winrt; then
        check_func_headers "windows.h" CreateThread &&
            enable w32threads || disable w32threads
    fi
fi

# check for some common methods of building with pthread support
# do this before the optional library checks as some of them require pthreads
if ! disabled pthreads && ! enabled w32threads && ! enabled os2threads; then
    enable pthreads
    if check_func pthread_join -pthread && check_func pthread_create -pthread; then
        add_cflags -pthread
        add_extralibs -pthread
    elif check_func pthread_join -pthreads && check_func pthread_create -pthreads; then
        add_cflags -pthreads
        add_extralibs -pthreads
    elif check_func pthread_join -ldl -pthread && check_func pthread_create -ldl -pthread; then
        add_cflags -ldl -pthread
        add_extralibs -ldl -pthread
    elif check_func pthread_join -lpthreadGC2 && check_func pthread_create -lpthreadGC2; then
        add_extralibs -lpthreadGC2
    elif check_lib pthread.h pthread_join -lpthread && check_lib pthread.h pthread_create -lpthread; then
        :
    elif ! check_func pthread_join && ! check_func pthread_create; then
        disable pthreads
    fi
    check_code cc "pthread.h" "static pthread_mutex_t atomic_lock = PTHREAD_MUTEX_INITIALIZER" || disable pthreads
fi


if enabled pthreads; then
  check_func pthread_cancel
fi

disabled  zlib || check_lib   zlib.h      zlibVersion -lz   || disable  zlib
disabled bzlib || check_lib2 bzlib.h BZ2_bzlibVersion -lbz2 || disable bzlib
disabled  lzma || check_lib2  lzma.h lzma_version_number -llzma || disable lzma

check_lib math.h sin -lm && LIBM="-lm"
disabled crystalhd || check_lib libcrystalhd/libcrystalhd_if.h DtsCrystalHDVersion -lcrystalhd || disable crystalhd

atan2f_args=2
copysign_args=2
hypot_args=2
ldexpf_args=2
powf_args=2

for func in $MATH_FUNCS; do
    eval check_mathfunc $func \${${func}_args:-1}
done

for func in $COMPLEX_FUNCS; do
    eval check_complexfunc $func \${${func}_args:-1}
done

# these are off by default, so fail if requested and not available
enabled avfoundation_indev && { check_header_objcc AVFoundation/AVFoundation.h || disable avfoundation_indev; }
enabled avfoundation_indev && { check_lib2 CoreGraphics/CoreGraphics.h CGGetActiveDisplayList -framework CoreGraphics ||
                                check_lib2 ApplicationServices/ApplicationServices.h CGGetActiveDisplayList -framework ApplicationServices; }
enabled avisynth          && { { check_lib2 "windows.h" LoadLibrary; } ||
                               { check_lib2 "dlfcn.h" dlopen -ldl; } ||
                               die "ERROR: LoadLibrary/dlopen not found for avisynth"; }
enabled chromaprint       && require chromaprint chromaprint.h chromaprint_get_version -lchromaprint
enabled decklink          && { check_header DeckLinkAPI.h || die "ERROR: DeckLinkAPI.h header not found"; }
enabled frei0r            && { check_header frei0r.h || die "ERROR: frei0r.h header not found"; }
enabled gmp               && require2 gmp gmp.h mpz_export -lgmp
enabled gnutls            && require_pkg_config gnutls gnutls/gnutls.h gnutls_global_init
enabled ladspa            && { check_header ladspa.h || die "ERROR: ladspa.h header not found"; }
enabled libiec61883       && require libiec61883 libiec61883/iec61883.h iec61883_cmp_connect -lraw1394 -lavc1394 -lrom1394 -liec61883
enabled libaacplus        && require "libaacplus >= 2.0.0" aacplus.h aacplusEncOpen -laacplus
enabled libass            && require_pkg_config libass ass/ass.h ass_library_init
enabled libbluray         && require_pkg_config libbluray libbluray/bluray.h bd_open
enabled libbs2b           && require_pkg_config libbs2b bs2b.h bs2b_open
enabled libcelt           && require libcelt celt/celt.h celt_decode -lcelt0 &&
                             { check_lib celt/celt.h celt_decoder_create_custom -lcelt0 ||
                               die "ERROR: libcelt must be installed and version must be >= 0.11.0."; }
enabled libcaca           && require_pkg_config caca caca.h caca_create_canvas
enabled libdcadec         && require_pkg_config "dcadec >= 0.1.0" libdcadec/dca_context.h dcadec_context_create
enabled libfaac           && require2 libfaac "stdint.h faac.h" faacEncGetVersion -lfaac
enabled libfdk_aac        && { use_pkg_config fdk-aac "fdk-aac/aacenc_lib.h" aacEncOpen ||
                               { require libfdk_aac fdk-aac/aacenc_lib.h aacEncOpen -lfdk-aac &&
                                 warn "using libfdk without pkg-config"; } }
flite_libs="-lflite_cmu_time_awb -lflite_cmu_us_awb -lflite_cmu_us_kal -lflite_cmu_us_kal16 -lflite_cmu_us_rms -lflite_cmu_us_slt -lflite_usenglish -lflite_cmulex -lflite"
enabled libflite          && require2 libflite "flite/flite.h" flite_init $flite_libs
enabled fontconfig        && enable libfontconfig
enabled libfontconfig     && require_pkg_config fontconfig "fontconfig/fontconfig.h" FcInit
enabled libfreetype       && require_libfreetype
enabled libfribidi        && require_pkg_config fribidi fribidi.h fribidi_version_info
enabled libgme            && require  libgme gme/gme.h gme_new_emu -lgme -lstdc++
enabled libgsm            && { for gsm_hdr in "gsm.h" "gsm/gsm.h"; do
                                   check_lib "${gsm_hdr}" gsm_create -lgsm && break;
                               done || die "ERROR: libgsm not found"; }
enabled libilbc           && require libilbc ilbc.h WebRtcIlbcfix_InitDecode -lilbc
enabled libkvazaar        && require_pkg_config "kvazaar >= 0.8.1" kvazaar.h kvz_api_get
enabled libmfx            && require_pkg_config libmfx "mfx/mfxvideo.h" MFXInit
enabled libmodplug        && require_pkg_config libmodplug libmodplug/modplug.h ModPlug_Load
enabled libmp3lame        && require "libmp3lame >= 3.98.3" lame/lame.h lame_set_VBR_quality -lmp3lame
enabled libnut            && require libnut libnut.h nut_demuxer_init -lnut
enabled libopencore_amrnb && require libopencore_amrnb opencore-amrnb/interf_dec.h Decoder_Interface_init -lopencore-amrnb
enabled libopencore_amrwb && require libopencore_amrwb opencore-amrwb/dec_if.h D_IF_init -lopencore-amrwb
enabled libopencv         && require_pkg_config opencv opencv/cxcore.h cvCreateImageHeader
enabled libopenh264       && require_pkg_config openh264 wels/codec_api.h WelsGetCodecVersion
enabled libopenjpeg       && { check_lib openjpeg-2.1/openjpeg.h opj_version -lopenjp2 -DOPJ_STATIC ||
                               check_lib openjpeg-2.0/openjpeg.h opj_version -lopenjp2 -DOPJ_STATIC ||
                               check_lib openjpeg-1.5/openjpeg.h opj_version -lopenjpeg -DOPJ_STATIC ||
                               check_lib openjpeg.h opj_version -lopenjpeg -DOPJ_STATIC ||
                               die "ERROR: libopenjpeg not found"; }
enabled libopus           && require_pkg_config opus opus_multistream.h opus_multistream_decoder_create
enabled libpulse          && require_pkg_config libpulse pulse/pulseaudio.h pa_context_new
enabled librtmp           && require_pkg_config librtmp librtmp/rtmp.h RTMP_Socket
enabled librubberband     && require_pkg_config "rubberband >= 1.8.1" rubberband/rubberband-c.h rubberband_new
enabled libschroedinger   && require_pkg_config schroedinger-1.0 schroedinger/schro.h schro_init
enabled libshine          && require_pkg_config shine shine/layer3.h shine_encode_buffer
enabled libsmbclient      && { use_pkg_config smbclient libsmbclient.h smbc_init ||
                               require smbclient libsmbclient.h smbc_init -lsmbclient; }
enabled libsnappy         && require snappy snappy-c.h snappy_compress -lsnappy
enabled libsoxr           && require libsoxr soxr.h soxr_create -lsoxr && LIBSOXR="-lsoxr"
enabled libssh            && require_pkg_config libssh libssh/sftp.h sftp_init
enabled libspeex          && require_pkg_config speex speex/speex.h speex_decoder_init -lspeex
enabled libtesseract      && require_pkg_config tesseract tesseract/capi.h TessBaseAPICreate
enabled libtheora         && require libtheora theora/theoraenc.h th_info_init -ltheoraenc -ltheoradec -logg
enabled libtwolame        && require libtwolame twolame.h twolame_init -ltwolame &&
                             { check_lib twolame.h twolame_encode_buffer_float32_interleaved -ltwolame ||
                               die "ERROR: libtwolame must be installed and version must be >= 0.3.10"; }
enabled libutvideo        && require_cpp utvideo "stdint.h stdlib.h utvideo/utvideo.h utvideo/Codec.h" 'CCodec*' -lutvideo -lstdc++
enabled libv4l2           && require_pkg_config libv4l2 libv4l2.h v4l2_ioctl
enabled libvidstab        && require_pkg_config "vidstab >= 0.98" vid.stab/libvidstab.h vsMotionDetectInit
enabled libvo_aacenc      && require libvo_aacenc vo-aacenc/voAAC.h voGetAACEncAPI -lvo-aacenc
enabled libvo_amrwbenc    && require libvo_amrwbenc vo-amrwbenc/enc_if.h E_IF_init -lvo-amrwbenc
enabled libvorbis         && require libvorbis vorbis/vorbisenc.h vorbis_info_init -lvorbisenc -lvorbis -logg

enabled libvpx            && {
    enabled libvpx_vp8_decoder && {
        use_pkg_config "vpx >= 0.9.1" "vpx/vpx_decoder.h vpx/vp8dx.h" vpx_codec_vp8_dx ||
            check_lib2 "vpx/vpx_decoder.h vpx/vp8dx.h" vpx_codec_dec_init_ver -lvpx ||
                die "ERROR: libvpx decoder version must be >=0.9.1";
    }
    enabled libvpx_vp8_encoder && {
        use_pkg_config "vpx >= 0.9.7" "vpx/vpx_encoder.h vpx/vp8cx.h" vpx_codec_vp8_cx ||
            check_lib2 "vpx/vpx_encoder.h vpx/vp8cx.h" "vpx_codec_enc_init_ver VP8E_SET_MAX_INTRA_BITRATE_PCT" -lvpx ||
                die "ERROR: libvpx encoder version must be >=0.9.7";
    }
    enabled libvpx_vp9_decoder && {
        use_pkg_config "vpx >= 1.3.0" "vpx/vpx_decoder.h vpx/vp8dx.h" vpx_codec_vp9_dx ||
            check_lib2 "vpx/vpx_decoder.h vpx/vp8dx.h" "vpx_codec_vp9_dx" -lvpx ||
                disable libvpx_vp9_decoder;
    }
    enabled libvpx_vp9_encoder && {
        use_pkg_config "vpx >= 1.3.0" "vpx/vpx_encoder.h vpx/vp8cx.h" vpx_codec_vp9_cx ||
            check_lib2 "vpx/vpx_encoder.h vpx/vp8cx.h" "vpx_codec_vp9_cx VP9E_SET_AQ_MODE" -lvpx ||
                disable libvpx_vp9_encoder;
    }
    if disabled_all libvpx_vp8_decoder libvpx_vp9_decoder libvpx_vp8_encoder libvpx_vp9_encoder; then
        die "libvpx enabled but no supported decoders found"
    fi
}

enabled libwavpack        && require libwavpack wavpack/wavpack.h WavpackOpenFileOutput  -lwavpack
enabled libwebp           && {
    enabled libwebp_encoder      && require_pkg_config "libwebp >= 0.2.0" webp/encode.h WebPGetEncoderVersion
    enabled libwebp_anim_encoder && { use_pkg_config "libwebpmux >= 0.4.0" webp/mux.h WebPAnimEncoderOptionsInit || disable libwebp_anim_encoder; } }
enabled libx264           && { use_pkg_config x264 "stdint.h x264.h" x264_encoder_encode ||
                               { require libx264 x264.h x264_encoder_encode -lx264 &&
                                 warn "using libx264 without pkg-config"; } } &&
                             { check_cpp_condition x264.h "X264_BUILD >= 118" ||
                               die "ERROR: libx264 must be installed and version must be >= 0.118."; } &&
                             { check_cpp_condition x264.h "X264_MPEG2" &&
                               enable libx262; }
enabled libx265           && require_pkg_config x265 x265.h x265_api_get &&
                             { check_cpp_condition x265.h "X265_BUILD >= 57" ||
                               die "ERROR: libx265 version must be >= 57."; }
enabled libxavs           && require libxavs xavs.h xavs_encoder_encode -lxavs
enabled libxvid           && require libxvid xvid.h xvid_global -lxvidcore
enabled libzimg           && require_pkg_config zimg zimg.h zimg_get_api_version
enabled libzmq            && require_pkg_config libzmq zmq.h zmq_ctx_new
enabled libzvbi           && require libzvbi libzvbi.h vbi_decoder_new -lzvbi
enabled mmal              && { check_lib interface/mmal/mmal.h mmal_port_connect -lmmal_core -lmmal_util -lmmal_vc_client -lbcm_host ||
                                { ! enabled cross_compile && {
                                    add_cflags -isystem/opt/vc/include/ -isystem/opt/vc/include/interface/vmcs_host/linux -isystem/opt/vc/include/interface/vcos/pthreads -fgnu89-inline ;
                                    add_extralibs -L/opt/vc/lib/ -lmmal_core -lmmal_util -lmmal_vc_client -lbcm_host ;
                                    check_lib interface/mmal/mmal.h mmal_port_connect ; }
                                check_lib interface/mmal/mmal.h mmal_port_connect ; } ||
                               die "ERROR: mmal not found"; }
enabled netcdf            && require_pkg_config netcdf netcdf.h nc_inq_libvers
enabled nvenc             && { check_header nvEncodeAPI.h || die "ERROR: nvEncodeAPI.h not found."; } &&
                             { check_cpp_condition nvEncodeAPI.h "NVENCAPI_MAJOR_VERSION >= 5" ||
                               die "ERROR: NVENC API version 4 or older is not supported"; } &&
                             { [ $target_os != cygwin ] || die "ERROR: NVENC is not supported on Cygwin currently."; }
enabled openal            && { { for al_libs in "${OPENAL_LIBS}" "-lopenal" "-lOpenAL32"; do
                               check_lib 'AL/al.h' alGetError "${al_libs}" && break; done } ||
                               die "ERROR: openal not found"; } &&
                             { check_cpp_condition "AL/al.h" "defined(AL_VERSION_1_1)" ||
                               die "ERROR: openal must be installed and version must be 1.1 or compatible"; }
enabled opencl            && { check_lib2 OpenCL/cl.h clEnqueueNDRangeKernel -Wl,-framework,OpenCL ||
                               check_lib2 CL/cl.h clEnqueueNDRangeKernel -lOpenCL ||
                               die "ERROR: opencl not found"; } &&
                             { check_cpp_condition "OpenCL/cl.h" "defined(CL_VERSION_1_2)" ||
                               check_cpp_condition "CL/cl.h" "defined(CL_VERSION_1_2)" ||
                               die "ERROR: opencl must be installed and version must be 1.2 or compatible"; }
enabled opengl            && { check_lib GL/glx.h glXGetProcAddress "-lGL" ||
                               check_lib2 windows.h wglGetProcAddress "-lopengl32 -lgdi32" ||
                               check_lib2 OpenGL/gl3.h glGetError "-Wl,-framework,OpenGL" ||
                               check_lib2 ES2/gl.h glGetError "-isysroot=${sysroot} -Wl,-framework,OpenGLES" ||
                               die "ERROR: opengl not found."
                             }
enabled openssl           && { check_lib openssl/ssl.h SSL_library_init -lssl -lcrypto ||
                               check_lib openssl/ssl.h SSL_library_init -lssl32 -leay32 ||
                               check_lib openssl/ssl.h SSL_library_init -lssl -lcrypto -lws2_32 -lgdi32 ||
                               die "ERROR: openssl not found"; }
enabled qtkit_indev      && { check_header_objcc QTKit/QTKit.h || disable qtkit_indev; }

# libdc1394 check
if enabled libdc1394; then
    { require_pkg_config libdc1394-2 dc1394/dc1394.h dc1394_new &&
        enable libdc1394_2; } ||
    { check_lib libdc1394/dc1394_control.h dc1394_create_handle -ldc1394_control -lraw1394 &&
        enable libdc1394_1; } ||
    die "ERROR: No version of libdc1394 found "
fi

if enabled gcrypt; then
    GCRYPT_CONFIG="${cross_prefix}libgcrypt-config"
    if "${GCRYPT_CONFIG}" --version > /dev/null 2>&1; then
        gcrypt_cflags=$("${GCRYPT_CONFIG}" --cflags)
        gcrypt_libs=$("${GCRYPT_CONFIG}" --libs)
        check_func_headers gcrypt.h gcry_mpi_new $gcrypt_cflags $gcrypt_libs ||
            die "ERROR: gcrypt not found"
        add_cflags $gcrypt_cflags && add_extralibs $gcrypt_libs
    else
        require2 gcrypt gcrypt.h gcry_mpi_new -lgcrypt
    fi
fi

if ! disabled sdl; then
    SDL_CONFIG="${cross_prefix}sdl-config"
    if check_pkg_config sdl SDL_events.h SDL_PollEvent; then
        check_cpp_condition SDL.h "(SDL_MAJOR_VERSION<<16 | SDL_MINOR_VERSION<<8 | SDL_PATCHLEVEL) >= 0x010201" $sdl_cflags &&
        check_cpp_condition SDL.h "(SDL_MAJOR_VERSION<<16 | SDL_MINOR_VERSION<<8 | SDL_PATCHLEVEL) < 0x010300" $sdl_cflags &&
        enable sdl
    else
        if "${SDL_CONFIG}" --version > /dev/null 2>&1; then
            sdl_cflags=$("${SDL_CONFIG}" --cflags)
            sdl_libs=$("${SDL_CONFIG}" --libs)
            check_func_headers SDL_version.h SDL_Linked_Version $sdl_cflags $sdl_libs &&
            check_cpp_condition SDL.h "(SDL_MAJOR_VERSION<<16 | SDL_MINOR_VERSION<<8 | SDL_PATCHLEVEL) >= 0x010201" $sdl_cflags &&
            check_cpp_condition SDL.h "(SDL_MAJOR_VERSION<<16 | SDL_MINOR_VERSION<<8 | SDL_PATCHLEVEL) < 0x010300" $sdl_cflags &&
            enable sdl
        elif enabled sdl ; then
            die "ERROR: SDL not found"
        else
            disable sdl
        fi
    fi
    if test $target_os = "mingw32"; then
        sdl_libs="$sdl_libs -mconsole"
    fi
fi
enabled sdl && add_cflags $sdl_cflags && add_extralibs $sdl_libs

disabled securetransport || { check_func SecIdentityCreate "-Wl,-framework,CoreFoundation -Wl,-framework,Security" &&
    check_lib2 "Security/SecureTransport.h Security/Security.h" "SSLCreateContext SecItemImport" "-Wl,-framework,CoreFoundation -Wl,-framework,Security" &&
    enable securetransport; }

disabled schannel || { check_func_headers "windows.h Security.h" InitializeSecurityContext -DSECURITY_WIN32 -lSecur32 &&
                       enable schannel && add_extralibs -lSecur32; }

makeinfo --version > /dev/null 2>&1 && enable makeinfo  || disable makeinfo
enabled makeinfo \
    && [ 0$(makeinfo --version | grep "texinfo" | sed 's/.*texinfo[^0-9]*\([0-9]*\)\..*/\1/') -ge 5 ] \
    && enable makeinfo_html || disable makeinfo_html
disabled makeinfo_html && texi2html --help 2> /dev/null | grep -q 'init-file' && enable texi2html || disable texi2html
perl -v            > /dev/null 2>&1 && enable perl      || disable perl
pod2man --help     > /dev/null 2>&1 && enable pod2man   || disable pod2man
rsync --help 2> /dev/null | grep -q 'contimeout' && enable rsync_contimeout || disable rsync_contimeout

check_header linux/fb.h
check_header linux/videodev.h
check_header linux/videodev2.h
check_code cc linux/videodev2.h "struct v4l2_frmsizeenum vfse; vfse.discrete.width = 0;" && enable_safe struct_v4l2_frmivalenum_discrete

check_header sys/videoio.h
check_code cc sys/videoio.h "struct v4l2_frmsizeenum vfse; vfse.discrete.width = 0;" && enable_safe struct_v4l2_frmivalenum_discrete

check_func_headers "windows.h vfw.h" capCreateCaptureWindow "$vfwcap_indev_extralibs"
# check that WM_CAP_DRIVER_CONNECT is defined to the proper value
# w32api 3.12 had it defined wrong
check_cpp_condition vfw.h "WM_CAP_DRIVER_CONNECT > WM_USER" && enable vfwcap_defines

check_type "dshow.h" IBaseFilter

# check for ioctl_meteor.h, ioctl_bt848.h and alternatives
{ check_header dev/bktr/ioctl_meteor.h &&
  check_header dev/bktr/ioctl_bt848.h; } ||
{ check_header machine/ioctl_meteor.h &&
  check_header machine/ioctl_bt848.h; } ||
{ check_header dev/video/meteor/ioctl_meteor.h &&
  check_header dev/video/bktr/ioctl_bt848.h; } ||
check_header dev/ic/bt8xx.h

check_header sndio.h
if check_struct sys/soundcard.h audio_buf_info bytes; then
    enable_safe sys/soundcard.h
else
    check_cc -D__BSD_VISIBLE -D__XSI_VISIBLE <<EOF && add_cppflags -D__BSD_VISIBLE -D__XSI_VISIBLE && enable_safe sys/soundcard.h
    #include <sys/soundcard.h>
    audio_buf_info abc;
EOF
fi
check_header soundcard.h

enabled_any alsa_indev alsa_outdev &&
    check_lib2 alsa/asoundlib.h snd_pcm_htimestamp -lasound

enabled jack_indev && check_lib2 jack/jack.h jack_client_open -ljack && check_func sem_timedwait &&
    check_func jack_port_get_latency_range -ljack

enabled_any sndio_indev sndio_outdev && check_lib2 sndio.h sio_open -lsndio

if enabled libcdio; then
    check_lib2 "cdio/cdda.h cdio/paranoia.h" cdio_cddap_open -lcdio_paranoia -lcdio_cdda -lcdio ||
    check_lib2 "cdio/paranoia/cdda.h cdio/paranoia/paranoia.h" cdio_cddap_open -lcdio_paranoia -lcdio_cdda -lcdio ||
    die "ERROR: No usable libcdio/cdparanoia found"
fi

enabled xlib &&
    check_lib X11/Xlib.h XOpenDisplay -lX11 || disable xlib

if ! disabled libxcb; then
    check_pkg_config "xcb >= 1.4" xcb/xcb.h xcb_connect || {
        enabled libxcb && die "ERROR: libxcb >= 1.4 not found";
    } && disable x11grab && enable libxcb

if enabled libxcb; then
    disabled libxcb_shm || {
        check_pkg_config xcb-shm xcb/shm.h xcb_shm_attach || {
            enabled libxcb_shm && die "ERROR: libxcb_shm not found";
        } && check_header sys/shm.h && enable libxcb_shm; }

    disabled libxcb_xfixes || {
        check_pkg_config xcb-xfixes xcb/xfixes.h xcb_xfixes_get_cursor_image || {
            enabled libxcb_xfixes && die "ERROR: libxcb_xfixes not found";
        } && enable libxcb_xfixes; }

    disabled libxcb_shape || {
        check_pkg_config xcb-shape xcb/shape.h xcb_shape_get_rectangles || {
            enabled libxcb_shape && die "ERROR: libxcb_shape not found";
        } && enable libxcb_shape; }

    add_cflags $xcb_cflags $xcb_shm_cflags $xcb_xfixes_cflags $xcb_shape_cflags
    add_extralibs $xcb_libs $xcb_shm_libs $xcb_xfixes_libs $xcb_shape_libs
fi
fi

if enabled x11grab; then
    enabled xlib || die "ERROR: Xlib not found"
    require Xext X11/extensions/XShm.h XShmCreateImage -lXext
    require Xfixes X11/extensions/Xfixes.h XFixesGetCursorImage -lXfixes
fi

check_func_headers "windows.h" CreateDIBSection "$gdigrab_indev_extralibs"

enabled dxva2api_h &&
    check_cc <<EOF && enable dxva2api_cobj
#define _WIN32_WINNT 0x0600
#define COBJMACROS
#include <windows.h>
#include <d3d9.h>
#include <dxva2api.h>
int main(void) { IDirectXVideoDecoder *o = NULL; IDirectXVideoDecoder_Release(o); return 0; }
EOF

enabled vaapi &&
    check_lib va/va.h vaInitialize -lva ||
    disable vaapi

enabled vaapi && enabled xlib &&
    check_lib2 "va/va.h va/va_x11.h" vaGetDisplay -lva -lva-x11 &&
    enable vaapi_x11

enabled vdpau &&
    check_cpp_condition vdpau/vdpau.h "defined VDP_DECODER_PROFILE_MPEG4_PART2_ASP" ||
    disable vdpau

enabled vdpau && enabled xlib &&
    check_func_headers "vdpau/vdpau.h vdpau/vdpau_x11.h" vdp_device_create_x11 -lvdpau &&
    prepend ffmpeg_libs $($ldflags_filter "-lvdpau") &&
    enable vdpau_x11

# Funny iconv installations are not unusual, so check it after all flags have been set
disabled iconv || check_func_headers iconv.h iconv || check_lib2 iconv.h iconv -liconv || disable iconv

enabled debug && add_cflags -g"$debuglevel" && add_asflags -g"$debuglevel"

# add some useful compiler flags if supported
check_cflags -Wdeclaration-after-statement
check_cflags -Wall
check_cflags -Wdisabled-optimization
check_cflags -Wpointer-arith
check_cflags -Wredundant-decls
check_cflags -Wwrite-strings
check_cflags -Wtype-limits
check_cflags -Wundef
check_cflags -Wmissing-prototypes
check_cflags -Wno-pointer-to-int-cast
check_cflags -Wstrict-prototypes
check_cflags -Wempty-body
enabled extra_warnings && check_cflags -Winline
enabled extra_warnings && check_cflags -Wcast-qual

check_disable_warning(){
    warning_flag=-W${1#-Wno-}
    test_cflags $warning_flag && add_cflags $1
}

check_disable_warning -Wno-parentheses
check_disable_warning -Wno-switch
check_disable_warning -Wno-format-zero-length
check_disable_warning -Wno-pointer-sign
check_disable_warning -Wno-unused-const-variable

# add some linker flags
check_ldflags -Wl,--warn-common
check_ldflags -Wl,-rpath-link=libpostproc:libswresample:libswscale:libavfilter:libavdevice:libavformat:libavcodec:libavutil:libavresample
enabled rpath && add_ldexeflags -Wl,-rpath,$libdir
enabled rpath && add_ldlibflags -Wl,-rpath,$libdir
test_ldflags -Wl,-Bsymbolic && append SHFLAGS -Wl,-Bsymbolic

# add some strip flags
# -wN '..@*' is more selective than -x, but not available everywhere.
check_stripflags -wN \'..@*\' || check_stripflags -x

enabled neon_clobber_test &&
    check_ldflags -Wl,--wrap,avcodec_open2              \
                  -Wl,--wrap,avcodec_decode_audio4      \
                  -Wl,--wrap,avcodec_decode_video2      \
                  -Wl,--wrap,avcodec_decode_subtitle2   \
                  -Wl,--wrap,avcodec_encode_audio2      \
                  -Wl,--wrap,avcodec_encode_video2      \
                  -Wl,--wrap,avcodec_encode_subtitle    \
                  -Wl,--wrap,swr_convert                \
                  -Wl,--wrap,avresample_convert ||
    disable neon_clobber_test

enabled xmm_clobber_test &&
    check_ldflags -Wl,--wrap,avcodec_open2              \
                  -Wl,--wrap,avcodec_decode_audio4      \
                  -Wl,--wrap,avcodec_decode_video2      \
                  -Wl,--wrap,avcodec_decode_subtitle2   \
                  -Wl,--wrap,avcodec_encode_audio2      \
                  -Wl,--wrap,avcodec_encode_video2      \
                  -Wl,--wrap,avcodec_encode_subtitle    \
                  -Wl,--wrap,swr_convert                \
                  -Wl,--wrap,avresample_convert         \
                  -Wl,--wrap,sws_scale ||
    disable xmm_clobber_test

echo "X { local: *; };" > $TMPV
if test_ldflags -Wl,--version-script,$TMPV; then
    append SHFLAGS '-Wl,--version-script,\$(SUBDIR)lib\$(NAME).ver'
elif test_ldflags -Wl,-M,$TMPV; then
    append SHFLAGS '-Wl,-M,\$(SUBDIR)lib\$(NAME).ver-sol2'
fi

check_cc <<EOF && enable symver_asm_label
void ff_foo(void) __asm__ ("av_foo@VERSION");
void ff_foo(void) { ${inline_asm+__asm__($quotes);} }
EOF
    check_cc <<EOF && enable symver_gnu_asm
__asm__(".symver ff_foo,av_foo@VERSION");
void ff_foo(void) {}
EOF

if [ -z "$optflags" ]; then
    if enabled small; then
        optflags=$cflags_size
    elif enabled optimizations; then
        optflags=$cflags_speed
    else
        optflags=$cflags_noopt
    fi
fi

check_optflags(){
    check_cflags "$@"
    enabled lto && check_ldflags "$@"
}


if enabled lto; then
    test "$cc_type" != "$ld_type" && die "LTO requires same compiler and linker"
    check_cflags  -flto
    check_ldflags -flto $cpuflags
    disable inline_asm_direct_symbol_refs
fi

check_optflags $optflags
check_optflags -fno-math-errno
check_optflags -fno-signed-zeros

enabled ftrapv && check_cflags -ftrapv

check_cc -mno-red-zone <<EOF && noredzone_flags="-mno-red-zone"
int x;
EOF


if enabled icc; then
    # Just warnings, no remarks
    check_cflags -w1
    # -wd: Disable following warnings
    # 144, 167, 556: -Wno-pointer-sign
    # 188: enumerated type mixed with another type
    # 1292: attribute "foo" ignored
    # 1419: external declaration in primary source file
    # 10006: ignoring unknown option -fno-signed-zeros
    # 10148: ignoring unknown option -Wno-parentheses
    # 10156: ignoring option '-W'; no argument required
    # 13200: No EMMS instruction before call to function
    # 13203: No EMMS instruction before return from function
    check_cflags -wd144,167,188,556,1292,1419,10006,10148,10156,13200,13203
    # 11030: Warning unknown option --as-needed
    # 10156: ignoring option '-export'; no argument required
    check_ldflags -wd10156,11030
    # icc 11.0 and 11.1 work with ebp_available, but don't pass the test
    enable ebp_available
    # The test above does not test linking
    enabled lto && disable symver_asm_label
    if enabled x86_32; then
        icc_version=$($cc -dumpversion)
        test ${icc_version%%.*} -ge 11 &&
            check_cflags -falign-stack=maintain-16-byte ||
            disable aligned_stack
    fi
elif enabled ccc; then
    # disable some annoying warnings
    add_cflags -msg_disable bitnotint
    add_cflags -msg_disable mixfuncvoid
    add_cflags -msg_disable nonstandcast
    add_cflags -msg_disable unsupieee
elif enabled gcc; then
    check_optflags -fno-tree-vectorize
    check_cflags -Werror=format-security
    check_cflags -Werror=implicit-function-declaration
    check_cflags -Werror=missing-prototypes
    check_cflags -Werror=return-type
    check_cflags -Werror=vla
    check_cflags -Wformat
    check_cflags -fdiagnostics-color=auto
    enabled extra_warnings || check_disable_warning -Wno-maybe-uninitialized
elif enabled llvm_gcc; then
    check_cflags -mllvm -stack-alignment=16
elif enabled clang; then
    check_cflags -mllvm -stack-alignment=16
    check_cflags -Qunused-arguments
    check_cflags -Werror=implicit-function-declaration
    check_cflags -Werror=missing-prototypes
    check_cflags -Werror=return-type
elif enabled cparser; then
    add_cflags -Wno-missing-variable-declarations
    add_cflags -Wno-empty-statement
elif enabled armcc; then
    add_cflags -W${armcc_opt},--diag_suppress=4343 # hardfp compat
    add_cflags -W${armcc_opt},--diag_suppress=3036 # using . as system include dir
    # 2523: use of inline assembly is deprecated
    add_cflags -W${armcc_opt},--diag_suppress=2523
    add_cflags -W${armcc_opt},--diag_suppress=1207
    add_cflags -W${armcc_opt},--diag_suppress=1293 # assignment in condition
    add_cflags -W${armcc_opt},--diag_suppress=3343 # hardfp compat
    add_cflags -W${armcc_opt},--diag_suppress=167  # pointer sign
    add_cflags -W${armcc_opt},--diag_suppress=513  # pointer sign
elif enabled tms470; then
    add_cflags -pds=824 -pds=837
    disable inline_asm
elif enabled pathscale; then
    add_cflags -fstrict-overflow -OPT:wrap_around_unsafe_opt=OFF
elif enabled_any msvc icl; then
    enabled x86_32 && disable aligned_stack
    enabled_all x86_32 debug && add_cflags -Oy-
    enabled debug && add_ldflags -debug
    enable pragma_deprecated
    if enabled icl; then
        # -Qansi-alias is basically -fstrict-aliasing, but does not work
        # (correctly) on icl 13.x.
        check_cpp_condition "windows.h" "__ICL < 1300 || __ICL >= 1400" &&
            add_cflags -Qansi-alias
        # Some inline asm is not compilable in debug
        if enabled debug; then
            disable ebp_available
            disable ebx_available
        fi
    fi
    # msvcrt10 x64 incorrectly enables log2, only msvcrt12 (MSVC 2013) onwards actually has log2.
    check_cpp_condition crtversion.h "_VC_CRT_MAJOR_VERSION >= 12" || disable log2
    # The CRT headers contain __declspec(restrict) in a few places, but if redefining
    # restrict, this might break. MSVC 2010 and 2012 fail with __declspec(__restrict)
    # (as it ends up if the restrict redefine is done before including stdlib.h), while
    # MSVC 2013 and newer can handle it fine.
    # If this declspec fails, force including stdlib.h before the restrict redefinition
    # happens in config.h.
    if [ $_restrict != restrict ]; then
        check_cc <<EOF || add_cflags -FIstdlib.h
__declspec($_restrict) void* foo(int);
EOF
    fi
    check_func strtoll || add_cflags -Dstrtoll=_strtoi64
fi

for pfx in "" host_; do
    varname=${pfx%_}cc_type
    eval "type=\$$varname"
    if [ $type = "msvc" ]; then
        check_${pfx}cc <<EOF || add_${pfx}cflags -Dinline=__inline
static inline int foo(int a) { return a; }
EOF
    fi
done