configuration for libav

[meweez]

Hello

I need to compile libav library with AFLGO. I have used these commands:

cd ~
export AFLGO=$PWD/aflgo
cd path/to/libav/folder
export SUBJECT=$PWD; export TMP_DIR=$PWD/obj-aflgo/temp
export CC=$AFLGO/afl-clang-fast
export CXX=$AFLGO/afl-clang-fast++
export COPY_CFLAGS=$CFLAGS
export COPY_CXXFLAGS=$CXXFLAGS
export ADDITIONAL="-targets=$TMP_DIR/BBtargets.txt -outdir=$TMP_DIR -flto -fuse-ld=gold -Wl,-plugin-opt=save-temps"
export CFLAGS="$CFLAGS $ADDITIONAL"
export CXXFLAGS="$CXXFLAGS $ADDITIONAL"
export LDFLAGS=-lpthread

./configure

it returns:

gcc is unable to create an executable file.
If gcc is a cross-compiler, use the --enable-cross-compile option.
Only do this if you know what cross compiling means.
C compiler test failed.

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
libav-tools@libav.org mailing list or IRC #libav on irc.freenode.net.
Include the log file "avbuild/config.log" produced by configure as this will help
solving the problem.

I have checked config.log but it doesn't seem useful, these are the last lines:

....
gcc -targets=/home/ubuntu16/Documents/github-repos/libav/obj-aflgo/temp/BBtargets.txt -outdir=/home/ubuntu16/Documents/$
gcc: error: unrecognized command line option '-targets=/home/ubuntu16/Documents/github-repos/libav/obj-aflgo/temp/BBtar$
C compiler test failed.

why does this try compile it with gcc again? I want to instrument it with AFLGo fuzzer.

Regards

[strongcourage]

First, make sure that you can compile libav with gcc.

mkdir obj; cd obj
../configure --disable-shared --prefix=`pwd`
make

Then, try to manually set variables CC, CXX ...

CC=$AFLGO/afl-clang-fast CXX= CFLAGS= ../configure --disable-shared --prefix=`pwd`

Best.

[meweez]

I'm sure that I can compile libav with gcc but again previous error for these commands:

pushd ~
export AFLGO=$PWD/aflgo
popd
export SUBJECT=$PWD; export TMP_DIR=$PWD/obj-aflgo/temp
export ADDITIONAL="-targets=$TMP_DIR/BBtargets.txt -outdir=$TMP_DIR -flto -fuse-ld=gold -Wl,-plugin-opt=save-temps"

CC=$AFLGO/afl-clang-fast CXX=$AFLGO/afl-clang-fast++ COPY_CFLAGS=$CFLAGS COPY_CXXFLAGS=$CXXFLAGS CFLAGS="$ADDITIONAL" CXXFLAGS="$ADDITIONAL" ./configure --disable-shared --prefix=`pwd`

gcc is unable to create an executable file.
If gcc is a cross-compiler, use the --enable-cross-compile option.
Only do this if you know what cross compiling means.
C compiler test failed.

[strongcourage]

Please give me some more info like version (commit) and your BBtargets so that I can try on my computer. Thanks.

[meweez]

this is my BBtargets.txt:

libavformat/dv.c:133
libavformat/dv.c:134
libavformat/dv.c:135
libavformat/dv.c:136
libavformat/dv.c:137

and I'm in head commit:
commit hash = c4642788e83b0858bca449f9b6e71ddb015dfa5d

[strongcourage]

I can compile libav. Please use the following commands:

mkdir obj-aflgo; cd obj-aflgo
export ADDITIONAL="-targets=$TMP_DIR/BBtargets.txt -outdir=$TMP_DIR -flto -fuse-ld=gold -Wl,-plugin-opt=save-temps"
../configure --disable-shared --prefix=`pwd` --cc=$AFLGO/afl-clang-fast --host-cflags="$ADDITIONAL" --disable-doc

For more information: configure --help. Best.

[strongcourage]

Feel free to open the issue if you have any further questions.