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

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

On Mon, Aug 04, 2025 at 11:20:38AM +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
>      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/backend/__init__.py b/scripts/tracetool/backend/__init__.py
> index 7bfcc86cc5..3c900f01e9 100644
> --- a/scripts/tracetool/backend/__init__.py
> +++ b/scripts/tracetool/backend/__init__.py
> @@ -23,6 +23,8 @@
>  Attribute Description
>  ========= ====================================================================
>  PUBLIC    If exists and is set to 'True', the backend is considered "public".
> +CHECK_TRACE_EVENT_GET_STATE    If exists and is set to 'True', generate function
> +emits code inside check_trace_event_get_state check.
>  ========= ====================================================================
>  
>  
> @@ -101,22 +103,32 @@ class Wrapper:
>      def __init__(self, backends, format):
>          self._backends = [backend.replace("-", "_") for backend in backends]
>          self._format = format.replace("-", "_")
> +        self.check_trace_event_get_state = False
>          for backend in self._backends:
>              assert exists(backend)
>          assert tracetool.format.exists(self._format)
> +        for backend in self.backend_modules():
> +            check_trace_event_get_state = getattr(backend, "CHECK_TRACE_EVENT_GET_STATE", False)
> +            self.check_trace_event_get_state = self.check_trace_event_get_state or check_trace_event_get_state
>  
> -    def _run_function(self, name, *args, **kwargs):
> +    def backend_modules(self):
>          for backend in self._backends:
> -            func = tracetool.try_import("tracetool.backend." + backend,
> -                                        name % self._format, None)[1]
> -            if func is not None:
> -                func(*args, **kwargs)
> +             module = tracetool.try_import("tracetool.backend." + backend)[1]
> +             if module is not None:
> +                 yield module
> +
> +    def _run_function(self, name, *args, check_trace_event_get_state=None, **kwargs):
> +        for backend in self.backend_modules():
> +            func = getattr(backend,name%self._format,None)
> +            if func is not None and (check_trace_event_get_state is None or
> +                    check_trace_event_get_state == getattr(backend, 'CHECK_TRACE_EVENT_GET_STATE', False)):
> +                    func(*args, **kwargs)

Something here is broken with the "simple" trace backend, as the entire
'.c' file content is no longer generated, causing link errors

With regards,
Daniel
-- 
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