Re: [PATCH v4 3/4] Rewrite "python" command exception handling

[Lancelot SIX <lancelot.six@amd.com>]

On Tue, Feb 27, 2024 at 07:45:51AM -0700, Tom Tromey wrote:
> The "python" command (and the Python implementation of the gdb
> "source" command) does not handle Python exceptions in the same way as
> other gdb-facing Python code.  In particular, exceptions are turned
> into a generic error rather than being routed through
> gdbpy_handle_exception, which takes care of converting to 'quit' as
> appropriate.
> 
> I think this was done this way because PyRun_SimpleFile and friends do
> not propagate the Python exception -- they simply indicate that one
> occurred.
> 
> This patch reimplements these functions to respect the general gdb
> convention here.  As a bonus, some Windows-specific code can be
> removed, as can the _execute_file function.
> 
> The bulk of this change is tweaking the test suite to match the new
> way that exceptions are displayed.  These changes are largely
> uninteresting.  However, it's worth pointing out the py-error.exp
> change.  Here, the failure changes because the test changes the host
> charset to something that isn't supported by Python.  This then
> results in a weird error in the new setup.
> 
> Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=31354
> Reviewed-By: Eli Zaretskii <eliz@gnu.org>
> Acked-By: Tom de Vries <tdevries@suse.de>

Hi Tom,

Our internal testing caught a regression introduced by this change.

Let's say you have a python script like this in /tmp/foo.py:

    if __name__ == "__main__":
        print(__file__)

Before this patch, we would have:

    $ gdb -batch -quiet -x /tmp/foo.py
    /tmp/foo.py

With this patch, we now have:

    $ gdb -batch -quiet -x /tmp/foo.py
    Python Exception <class 'NameError'>: name '__file__' is not defined
    Error occurred in Python: name '__file__' is not defined

I have not looked into much details, but can try to have a look if you
don't have time.

Best,
Lancelot.