Re: [PATCH v4 3/9] tests/functional: Provide GDB to the functional tests

[Gustavo Romero <gustavo.romero@linaro.org>]

Hi Thomas,

On 9/26/25 15:08, Gustavo Romero wrote:
> Hi Thomas,
> 
> On 9/26/25 07:03, Thomas Huth wrote:
>> On 26/09/2025 07.15, Gustavo Romero wrote:
>>> The probe of GDB is done in 'configure' and the full path is passed to
>>> meson.build via the -Dgdb=option.
>>>
>>> Because a single functional test can cover different arches, such as
>>> aarch64, ppc64, and x86_64, only a GDB that supports all the arches in
>>> the target list is passed to Meson for use in the functional tests. To
>>> handle this check, a new shell function, is_target_arch_in_arch_list, is
>>> introduced in 'configure'.
>>>
>>> Meson then can pass the location of GDB to the test via an environment
>>> variable: QEMU_TEST_GDB.
>>>
>>> Signed-off-by: Gustavo Romero <gustavo.romero@linaro.org>
>>> Signed-off-by: Thomas Huth <thuth@redhat.com>
>>> ---
>>>   configure                     | 21 +++++++++++++++++++++
>>>   meson_options.txt             |  2 ++
>>>   scripts/meson-buildoptions.sh |  2 ++
>>>   tests/functional/meson.build  |  6 ++++++
>>>   4 files changed, 31 insertions(+)
>>>
>>> diff --git a/configure b/configure
>>> index 0f7eb95586..20e05d233f 100755
>>> --- a/configure
>>> +++ b/configure
>>> @@ -1142,12 +1142,31 @@ fi
>>>   #########################################
>>>   # gdb test
>>> +# Check if all target arches are in a provided list of arches.
>>> +is_target_arch_in_arch_list() {
>>> +    arch_list=$1
>>> +    for target in $target_list; do
>>> +        arch=${target%%-*}
>>> +        if test "${arch_list#*$arch}" = "$arch_list"; then
>>> +            # Target arch not in arch list
>>> +            return 1
>>> +        fi
>>> +    done
>>> +    return 0
>>> +}
>>> +
>>>   if test -n "$gdb_bin"; then
>>>       gdb_version_string=$($gdb_bin --version | head -n 1)
>>>       # Extract last field in the version string
>>>       gdb_version=${gdb_version_string##* }
>>>       if version_ge $gdb_version 9.1; then
>>>           gdb_arches=$($python "$source_path/scripts/probe-gdb-support.py" $gdb_bin)
>>> +
>>> +    if is_target_arch_in_arch_list "$gdb_arches"; then
>>
>> No TABs, please!
>>
>>> +            gdb_multiarch="yes"
>>> +        else
>>> +            gdb_multiarch=""
>>> +    fi
>>
>> This unfortunately does not work with the GDB from Fedora - it only supports "arch64_be arm riscv64 riscv32 ppc i386 s390x ppc64 aarch64 ppc64le x86_64", but if you configured a target like "alpha-softmmu", this breaks.
> 
> argh! ok
> 
> 
>> (BTW, does the gdb-multiarch from Debian/Ubuntu really also support exotic QEMU targets like tricore?)
> 
> No, I've checked GDB upstream and I can't see any trace of tricore.
> And I just saw that Alex left a comment in scripts/probe-gdb-support.py
> saying "# no tricore in upstream gdb", so nope, it seems that it still holds.
> 
> 
>> I think it would be better to drop this hunk, and rather check in the spot where we use GDB if the required target is really there (i.e. in the functional test that uses it).
> 
> OK. I'm also not a big fan of doing it in bash. How do you suggest
> to do it? Directly in the code, via a skipIf decorator, or something else?

$gdb_arches, obtained using scripts/probe-gdb-support.py in configure,
could be passed to meson and meson sets it in the test env, as we're
doing for $gdb_bin and QEMU_TEST_GDB env var. wdyt?


Cheers,
Gustavo