Re: [PATCH v2 1/2] tracetool: add CHECK_TRACE_EVENT_GET_STATE

["Daniel P. Berrangé" <berrange@redhat.com>]

On Wed, Aug 06, 2025 at 03:05:38PM +0000, Tanish Desai wrote:
> New attributed added in backends
> CHECK_TRACE_EVENT_GET_STATE which when
> present and is True wraps the code generated
> by generate function in check_trace_event_get_state
> check else it is outside the conditional block.
> 
> Signed-off-by: Tanish Desai <tanishdesai37@gmail.com>
> ---
>  scripts/tracetool/__init__.py         |  1 -
>  scripts/tracetool/backend/__init__.py | 26 ++++++++++++++++-------
>  scripts/tracetool/format/h.py         | 30 ++++++++++-----------------
>  3 files changed, 30 insertions(+), 27 deletions(-)
> 
> diff --git a/scripts/tracetool/__init__.py b/scripts/tracetool/__init__.py
> index 2ae2e562d6..d0a02c45d7 100644
> --- a/scripts/tracetool/__init__.py
> +++ b/scripts/tracetool/__init__.py
> @@ -332,7 +332,6 @@ def formats(self):
>          return self._FMT.findall(self.fmt)
>  
>      QEMU_TRACE               = "trace_%(name)s"
> -    QEMU_TRACE_NOCHECK       = "_nocheck__" + QEMU_TRACE

This is just removing obsolete code

>      QEMU_TRACE_TCG           = QEMU_TRACE + "_tcg"
>      QEMU_DSTATE              = "_TRACE_%(NAME)s_DSTATE"
>      QEMU_BACKEND_DSTATE      = "TRACE_%(NAME)s_BACKEND_DSTATE"

> diff --git a/scripts/tracetool/format/h.py b/scripts/tracetool/format/h.py
> index ea126b07ea..0ceb49eef5 100644
> --- a/scripts/tracetool/format/h.py
> +++ b/scripts/tracetool/format/h.py
> @@ -59,33 +59,25 @@ def generate(events, backend, group):
>  
>          out('    false)')
>  
> -        # tracer without checks
>          out('',
>              'static inline void %(api)s(%(args)s)',
>              '{',
> -            api=e.api(e.QEMU_TRACE_NOCHECK),
> +            api=e.api(),
>              args=e.args)

This bit is removing more obsolete code

>  
>          if "disable" not in e.properties:
> -            backend.generate(e, group)
> -
> +            backend.generate(e, group, check_trace_event_get_state=False)
> +
> +        if backend.check_trace_event_get_state:
> +            if "disable" not in e.properties:
> +                event_id = 'TRACE_' + e.name.upper()
> +                cond = "trace_event_get_state(%s)" % event_id
> +                out('    if (%(cond)s) {',
> +                        cond=cond)
> +                backend.generate(e, group, check_trace_event_get_state=True)
> +                out('    }')
>          out('}')

This is the actual new functionality

>  
> -        cond = "true"
> -
> -        out('',
> -            'static inline void %(api)s(%(args)s)',
> -            '{',
> -            '    if (%(cond)s) {',
> -            '        %(api_nocheck)s(%(names)s);',
> -            '    }',
> -            '}',
> -            api=e.api(),
> -            api_nocheck=e.api(e.QEMU_TRACE_NOCHECK),
> -            args=e.args,
> -            names=", ".join(e.args.names()),
> -            cond=cond)
> -

This is further obsolete code.

It is best to have new functionality added in a separate commit
from the removal of obsolete code.

I've co-incidentally got removal of this obsolete code in the
tracing test suite series I posted, so one will need to be
rebased on top of the other, depending on what order Stefan
wants to take the patches.

>      backend.generate_end(events, group)
>  
>      out('#endif /* TRACE_%s_GENERATED_TRACERS_H */' % group.upper())
> -- 
> 2.34.1
> 
> 

With regards,
Daniel
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