Re: [PATCH] Add option to disable building tests

[BALATON Zoltan <balaton@eik.bme.hu>]

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On Mon, 27 Jul 2026, Thomas Huth wrote:
> On 27/07/2026 10.12, Philippe Mathieu-Daudé wrote:
>> On 24/7/26 18:45, Pierrick Bouvier wrote:
>>> On 7/24/2026 6:54 AM, Florian Schmidt wrote:
>>>> There are situations in which you might want to build QEMU without
>>>> building the full test suite, which in some configurations can take a
>>>> considerable amount of time to build. This is especially true when using
>>>> LTO with clang. For example:
>>>> 
>>>> $ ../configure --cc=clang '--extra-ldflags=-flto=thin -ffat-lto-objects' 
>>>> '--extra-cflags=-flto=thin -ffat-lto-objects' 
>>>> --target-list=x86_64-softmmu
>>>> [...]
>>>> $ time make -j8
>>>> [...]
>>>> [3078/3078] Linking target tests/qtest/qos-test
>>>> real    6m43.250s
>>>> user    101m15.967s
>>>> sys     4m3.813s
>>>> 
>>>> $ ../configure --cc=clang '--extra-ldflags=-flto=thin -ffat-lto-objects' 
>>>> '--extra-cflags=-flto=thin -ffat-lto-objects' --target-list=x86_64- 
>>>> softmmu --disable-tests
>>>> [...]
>>>> $ time make -j8
>>>> [...]
>>>> [2024/2024] Linking target qemu-system-x86_64
>>>> 
>>>> real    3m14.277s
>>>> user    33m13.174s
>>>> sys     1m36.642s
>>>> 
>>>> Add a toggle to optionally disable building tests.
>>>> 
>>>> Signed-off-by: Florian Schmidt <flosch@nutanix.com>
>>>> ---
>>>>   meson.build                   | 2 +-
>>>>   meson_options.txt             | 2 ++
>>>>   scripts/meson-buildoptions.sh | 3 +++
>>>>   3 files changed, 6 insertions(+), 1 deletion(-)
>>>> 
>>>> diff --git a/meson.build b/meson.build
>>>> index 49a5baf5b5..ad728c26ec 100644
>>>> --- a/meson.build
>>>> +++ b/meson.build
>>>> @@ -4605,7 +4605,7 @@ subdir('docs')
>>>>   subdir('pyvenv')
>>>>   # Tests are disabled on emscripten because they rely on host features 
>>>> that aren't
>>>>   # supported by emscripten (e.g. fork and unix socket).
>>>> -if host_os != 'emscripten'
>>>> +if get_option('tests').allowed() and host_os != 'emscripten'
>>>>     subdir('tests')
>>>>   endif
>>>>   if gtk.found()
>>>> diff --git a/meson_options.txt b/meson_options.txt
>>>> index a07cb47d35..68333ca402 100644
>>>> --- a/meson_options.txt
>>>> +++ b/meson_options.txt
>>>> @@ -43,6 +43,8 @@ option('gdb', type: 'string', value: '',
>>>>   # on the configure script command line.  After adding an option
>>>>   # here make sure to run "make update-buildoptions".
>>>> +option('tests', type: 'feature', value: 'auto',
>>>> +       description: 'Build the test suite')
>>>>   option('docs', type : 'feature', value : 'auto',
>>>>          description: 'Documentations build support')
>>>>   option('fuzzing', type : 'boolean', value: false,
>>>> diff --git a/scripts/meson-buildoptions.sh 
>>>> b/scripts/meson-buildoptions.sh
>>>> index c003985047..3fec13a336 100644
>>>> --- a/scripts/meson-buildoptions.sh
>>>> +++ b/scripts/meson-buildoptions.sh
>>>> @@ -194,6 +194,7 @@ meson_options_help() {
>>>>     printf "%s\n" '  spice-protocol  Spice protocol support'
>>>>     printf "%s\n" '  stack-protector compiler-provided stack protection'
>>>>     printf "%s\n" '  tcg             TCG support'
>>>> +  printf "%s\n" '  tests           build test suite'
>>>>     printf "%s\n" '  tools           build support utilities that come 
>>>> with QEMU'
>>>>     printf "%s\n" '  tpm             TPM support'
>>>>     printf "%s\n" '  u2f             U2F emulation support'
>>>> @@ -515,6 +516,8 @@ _meson_option_parse() {
>>>>       --enable-tcg-interpreter) printf "%s" -Dtcg_interpreter=true ;;
>>>>       --disable-tcg-interpreter) printf "%s" -Dtcg_interpreter=false ;;
>>>>       --tls-priority=*) quote_sh "-Dtls_priority=$2" ;;
>>>> +    --enable-tests) printf "%s" -Dtests=enabled ;;
>>>> +    --disable-tests) printf "%s" -Dtests=disabled ;;
>>>>       --enable-tools) printf "%s" -Dtools=enabled ;;
>>>>       --disable-tools) printf "%s" -Dtools=disabled ;;
>>>>       --enable-tpm) printf "%s" -Dtpm=enabled ;;
>>> 
>>> That's a great addition, including just for speeding up normal builds.
>>> 
>>> Reviewed-by: Pierrick Bouvier <pierrick.bouvier@oss.qualcomm.com>
>>> Tested-by: Pierrick Bouvier <pierrick.bouvier@oss.qualcomm.com>
>>> 
>>> If we want to overengineer the thing, it could be possible to still
>>> declare all tests, but not build them by default. However, it's probably
>>> too error prone and much less simple than this patch. So I don't think
>>> it's a good idea.
>>> 
>>> Regards,
>>> Pierrick
>>> 
>> 
>> When is it useful to build without the provided test suite?
> I sometimes wished indeed for a --disable-tests switch in the past already 
> (was just too lazy to contribute a patch): I'm sometimes building QEMU in a 
> separate directory, just for a very special case like testing a patch with an 
> --enable-asan build, or for doing a "git bisect". In such cases, I never want 
> to run the normal tests since it's simply not necessary. I run the tests from 
> my main build directory instead once I have a final patch and want to 
> contribute it to upstream. So IMHO this patch is a good idea.

I similarly have a local patch for this for such usage, that I never 
cleaned up to submit but I think it's a good idea.

Regards,
BALATON Zoltan