Re: [PATCH] Add execute bit back to scripts/tracetool.py

[Daniel P . Berrangé]

On Wed, Sep 23, 2020 at 01:14:57PM +0200, Paolo Bonzini wrote:
> On 23/09/20 12:36, Anthony PERARD wrote:
> > Commit a81df1b68b65 ("libqemuutil, qapi, trace: convert to meson")
> > removed it without explanation and it is useful to be able to run a
> > script without having to figure out which interpreter to use.
> > 
> > Signed-off-by: Anthony PERARD <anthony.perard@citrix.com>
> > ---
> >  scripts/tracetool.py | 0
> >  1 file changed, 0 insertions(+), 0 deletions(-)
> >  mode change 100644 => 100755 scripts/tracetool.py
> > 
> > diff --git a/scripts/tracetool.py b/scripts/tracetool.py
> > old mode 100644
> > new mode 100755
> > 
> 
> The explanation is in docs/devel/build-system.rst
> 
> Support scripts
> ---------------
> 
> Meson has a special convention for invoking Python scripts: if their
> first line is `#! /usr/bin/env python3` and the file is *not* executable,
> find_program() arranges to invoke the script under the same Python
> interpreter that was used to invoke Meson.  This is the most common
> and preferred way to invoke support scripts from Meson build files,
> because it automatically uses the value of configure's --python= option.
> 
> In case the script is not written in Python, use a `#! /usr/bin/env ...`
> line and make the script executable.
> 
> Scripts written in Python, where it is desirable to make the script
> executable (for example for test scripts that developers may want to
> invoke from the command line, such as tests/qapi-schema/test-qapi.py),
> should be invoked through the `python` variable in meson.build. For
> example::
> 
>   test('QAPI schema regression tests', python,
>        args: files('test-qapi.py'),
>        env: test_env, suite: ['qapi-schema', 'qapi-frontend'])
> 
> This is needed to obey the --python= option passed to the configure
> script, which may point to something other than the first python3
> binary on the path.

The top level meson.build sets


  tracetool = [
    python, files('scripts/tracetool.py'),
     '--backend=' + config_host['TRACE_BACKENDS']
  ]

So looks like we're correctly honouring the configured --python
binary, and thus setting the executable bit will not cause any
problems with meson.

Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>

Regards,
Daniel
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