#5158: Configure error with clang on Android NDK
-------------------------------------+-------------------------------------
Reporter: pracucci | Type: defect
Status: new | Priority: normal
Component: | Version:
undetermined | unspecified
Keywords: | Blocked By:
Blocking: | Reproduced by developer: 0
Analyzed by developer: 0 |
-------------------------------------+-------------------------------------
I successfully build and run in production ffmpeg on Android (arm and x86)
compiled with Android NDK's gcc. Recently, Android deprecated gcc and is
pushing every dev to migrate to clang.
I'm getting some issues while compiling ffmpeg with Android NDK's clang
and this is the first one I encounter:
> GNU assembler not found, install/update gas-preprocessor
Despite the message, looks that error is more subtle. Below you can find
the full instructions to reproduce it (it fixes with `--disable-asm` but
with gcc I'm able to compile with asm support).
Versions:
- ffmpeg 2.8.4
- Compile on OSX 10.9.5
### Download Android NDK
You can download the Android NDK from here:
http://developer.android.com/ndk/downloads/index.html
### Install Android NDK
Follow the installation instructions in the download and then set the
environment variable `NDK_DIR` to the directory where you extracted the
NDK.
### Build NDK standalone toolchain
Define an environment variable `TOOLCHAIN_DIR` with the full path of the
directory where the standalone toolchain should be installed. For example:
`export TOOLCHAIN_DIR=/tmp/toolchain`
Then build the toolchain:
${NDK_DIR}/build/tools/make-standalone-toolchain.sh \
--toolchain=arm-linux-androideabi-clang3.6 \
--platform=android-9 \
--install-dir=${TOOLCHAIN_DIR}
### Compile ffmpeg
The the following configure script:
./configure \
--enable-shared \
--disable-static \
--enable-gpl \
--enable-version3 \
--enable-nonfree \
--disable-runtime-cpudetect \
--disable-all \
--disable-doc \
--enable-avcodec \
--enable-avformat \
--enable-avutil \
--enable-swresample \
--disable-w32threads \
--disable-os2threads \
--disable-network \
--disable-dxva2 \
--disable-vaapi \
--disable-vda \
--disable-vdpau \
--enable-protocol="file" \
--enable-decoder="aac" \
--enable-decoder="cook" \
--enable-decoder="flac" \
--enable-decoder="mp3" \
--enable-decoder="mp3adu" \
--enable-decoder="mp3adufloat" \
--enable-decoder="mp3float" \
--enable-decoder="mp3on4" \
--enable-decoder="mp3on4float" \
--enable-decoder="pcm_alaw" \
--enable-decoder="pcm_bluray" \
--enable-decoder="pcm_dvd" \
--enable-decoder="pcm_f32be" \
--enable-decoder="pcm_f32le" \
--enable-decoder="pcm_f64be" \
--enable-decoder="pcm_f64le" \
--enable-decoder="pcm_lxf" \
--enable-decoder="pcm_mulaw" \
--enable-decoder="pcm_s16be" \
--enable-decoder="pcm_s16be_planar" \
--enable-decoder="pcm_s16le" \
--enable-decoder="pcm_s16le_planar" \
--enable-decoder="pcm_s24be" \
--enable-decoder="pcm_s24daud" \
--enable-decoder="pcm_s24le" \
--enable-decoder="pcm_s24le_planar" \
--enable-decoder="pcm_s32be" \
--enable-decoder="pcm_s32le" \
--enable-decoder="pcm_s32le_planar" \
--enable-decoder="pcm_s8" \
--enable-decoder="pcm_s8_planar" \
--enable-decoder="pcm_u16be" \
--enable-decoder="pcm_u16le" \
--enable-decoder="pcm_u24be" \
--enable-decoder="pcm_u24le" \
--enable-decoder="pcm_u32be" \
--enable-decoder="pcm_u32le" \
--enable-decoder="pcm_u8" \
--enable-decoder="pcm_zork" \
--enable-decoder="ra_144" \
--enable-decoder="ra_288" \
--enable-decoder="ralf" \
--enable-decoder="vorbis" \
--enable-decoder="wmav1" \
--enable-decoder="wmav2" \
--enable-decoder="wmavoice" \
--enable-decoder="wmalossless" \
--enable-decoder="wmapro" \
--enable-parser="aac" \
--enable-parser="flac" \
--enable-parser="mpegaudio" \
--enable-parser="vorbis" \
--enable-demuxer="aac" \
--enable-demuxer="aiff" \
--enable-demuxer="asf" \
--enable-demuxer="flac" \
--enable-demuxer="ogg" \
--enable-demuxer="mp3" \
--enable-demuxer="mov" \
--enable-demuxer="pcm_alaw" \
--enable-demuxer="pcm_f32be" \
--enable-demuxer="pcm_f32le" \
--enable-demuxer="pcm_f64be" \
--enable-demuxer="pcm_f64le" \
--enable-demuxer="pcm_mulaw" \
--enable-demuxer="pcm_s16be" \
--enable-demuxer="pcm_s16le" \
--enable-demuxer="pcm_s24be" \
--enable-demuxer="pcm_s24le" \
--enable-demuxer="pcm_s32be" \
--enable-demuxer="pcm_s32le" \
--enable-demuxer="pcm_s8" \
--enable-demuxer="pcm_u16be" \
--enable-demuxer="pcm_u16le" \
--enable-demuxer="pcm_u24be" \
--enable-demuxer="pcm_u24le" \
--enable-demuxer="pcm_u32be" \
--enable-demuxer="pcm_u32le" \
--enable-demuxer="rm" \
--enable-demuxer="wav" \
--enable-cross-compile \
--toolchain=clang-usan \
--cross-prefix=${TOOLCHAIN_DIR}/bin/arm-linux-androideabi- \
--cc=${TOOLCHAIN_DIR}/bin/arm-linux-androideabi-clang \
--cxx=${TOOLCHAIN_DIR}/bin/arm-linux-androideabi-clang \
--sysroot=${TOOLCHAIN_DIR}/sysroot \
--target-os=android \
--extra-cflags="-I${TOOCHAIN_DIR}/sysroot/usr/include -ffast-math
-funroll-loops -march=armv7-a -mfloat-abi=softfp -mfpu=vfpv3-d16" \
--extra-ldflags="-L${TOOCHAIN_DIR}/sysroot/usr/lib" \
--arch="arm" \
--logfile="/tmp/ffmpeg.log"
The configure script fails with:
GNU assembler not found, install/update gas-preprocessor
It fails while running `check_as` (extracted from the fail of ffmpeg.log):
check_as
BEGIN /var/folders/zn/45tzvzd15tnfvp4g5847x2dm0000gn/T//ffconf.a7i3f9zc.S
1 .altmacro
END /var/folders/zn/45tzvzd15tnfvp4g5847x2dm0000gn/T//ffconf.a7i3f9zc.S
/tmp/toolchain/bin/arm-linux-androideabi-clang
--sysroot=/tmp/toolchain/sysroot -isysroot /tmp/toolchain/sysroot
-D_ISOC99_SOURCE -D_FILE_OFFSET_BITS=64 -D_LARGEFILE_SOURCE
-Dstrtod=avpriv_strtod -DPIC -I/sysroot/usr/include -ffast-math -funroll-
loops -march=armv7-a -mfloat-abi=softfp -mfpu=vfpv3-d16 -march=armv7-a
-fPIC -c -o
/var/folders/zn/45tzvzd15tnfvp4g5847x2dm0000gn/T//ffconf.Ct6YZsBn.o
/var/folders/zn/45tzvzd15tnfvp4g5847x2dm0000gn/T//ffconf.a7i3f9zc.S
/var/folders/zn/45tzvzd15tnfvp4g5847x2dm0000gn/T//ffconf.a7i3f9zc.S:1:1:
error: unknown directive
.altmacro
GNU assembler not found, install/update gas-preprocessor
The weird thing is that if I create a file containing `.altmacro` and run
the same exact command it actually works. For example:
$ echo ".altmacro" > test.as
$ /tmp/toolchain/bin/arm-linux-androideabi-clang
--sysroot=/tmp/toolchain/sysroot -isysroot /tmp/toolchain/sysroot
-D_ISOC99_SOURCE -D_FILE_OFFSET_BITS=64 -D_LARGEFILE_SOURCE
-Dstrtod=avpriv_strtod -DPIC -I/sysroot/usr/include -ffast-math -funroll-
loops -march=armv7-a -mfloat-abi=softfp -mfpu=vfpv3-d16 -march=armv7-a
-fPIC -c -o /tmp/test.o test.as
$ echo $?
0
After digging for an hour in the configure script I can't actually realize
why it fails. Do you have any hint?
Thank you!
--
Ticket URL: <https://trac.ffmpeg.org/ticket/5158>
FFmpeg <https://ffmpeg.org>
FFmpeg issue tracker
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