Re: [Question] Fuzz: No rule to make target 'i386-softmmu/fuzz'

[Alexander Bulekov]

On 201106 2104, liqiuhao727 wrote:
> Hi,
> 
> I am a newbie to QEMU and trying to build the virtual-device fuzzer
> according to qemu/docs/devel/fuzzing.txt, which says:
> 
> ---
> Configure with (substitute the clang binaries with the version you
> installed).
> ...
>     CC=clang-8 CXX=clang++-8 /path/to/configure --enable-fuzzing \
>                                                 --enable-sanitizers
> Fuzz targets are built similarly to system/softmmu:

Ah, these instructions went out of date when QEMU switched to meson.
I'll send a patch to update them.

>     make i386-softmmu/fuzz
> This builds ./i386-softmmu/qemu-fuzz-i386

This should be:
make qemu-fuzz-i386

It looks like you are running these commands from the root qemu
directory, so the resulting binary should be
./build/qemu-fuzz-i386

There are a couple fixes to the fuzzers that should be applied soon, so
it might be a good idea to grab updated sources soon. They are part of
this pull-req:

https://lists.gnu.org/archive/html/qemu-devel/2020-11/msg01142.html

-Alex

> ---
> 
> But when I did this on my Ubuntu 20.04 x86-64 with qemu-5.2.0-rc0
> release code, the make complained it could not find the target:
> 
> ---
> root@iZj6canc2b2vgdozetp9foZ:~/qemu# CC=clang-10 CXX=clang++-10
> ./configure --enable-fuzzing --enable-sanitizers > configure.log
> root@iZj6canc2b2vgdozetp9foZ:~/qemu# make i386-softmmu/fuzz
> changing dir to build for make "i386-softmmu/fuzz"...
> make[1]: Entering directory '/root/qemu/build'
> /usr/bin/ninja  build.ninja && touch build.ninja.stamp
> ninja: no work to do.
> /usr/bin/python3 -B /root/qemu/meson/meson.py introspect --targets --
> tests --benchmarks | /usr/bin/python3 -B scripts/mtest2make.py >
> Makefile.mtest
> make[1]: *** No rule to make target 'i386-softmmu/fuzz'.  Stop.
> make[1]: Leaving directory '/root/qemu/build'
> make: *** [GNUmakefile:11: i386-softmmu/fuzz] Error 2
> ---
> 
> Did I missed something or misunderstood the instructions?
> Thanks.