Re: [PATCH 02/10] gdb/python: make the gdb.unwinder.Unwinder class more robust

[Simon Marchi <simark@simark.ca>]

On 3/10/23 09:55, Andrew Burgess via Gdb-patches wrote:
> This commit makes a few related changes to the gdb.unwinder.Unwinder
> class attributes:
> 
>   1. The 'name' attribute is now a read-only attribute.  This prevents
>   user code from changing the name after registering the unwinder.  It
>   seems very unlikely that any user is actually trying to do this in
>   the wild, so I'm not very worried that this will upset anyone,
> 
>   2. We now validate that the name is a string in the
>   Unwinder.__init__ method, and throw an error if this is not the
>   case.  Hopefully nobody was doing this in the wild.  This should
>   make it easier to ensure the 'info unwinder' command shows sane
>   output (how to display a non-string name for an unwinder?),
> 
>   3. The 'enabled' attribute is now implemented with a getter and
>   setter.  In the setter we ensure that the new value is a boolean,
>   but the real important change is that we call
>   'gdb.invalidate_cached_frames()'.  This means that the backtrace
>   will be updated if a user manually disables an unwinder (rather than
>   calling the 'disable unwinder' command).  It is not unreasonable to
>   think that a user might register multiple unwinders (relating to
>   some project) and have one command that disables/enables all the
>   related unwinders.  This command might operate by poking the enabled
>   attribute of each unwinder object directly, after this commit, this
>   would now work correctly.
> 
> There's tests for all the changes, and lots of documentation updates
> that both cover the new changes, but also further improve (I think)
> the general documentation for GDB's Unwinder API.

Hi Andrew,

With this commit, I see:

    python global_test_unwinder.name = "foo"^M
    Traceback (most recent call last):^M
      File "<string>", line 1, in <module>^M
    AttributeError: can't set attribute 'name'^M
    Error while executing Python code.^M
    (gdb) FAIL: gdb.python/py-unwind.exp: python global_test_unwinder.name = "foo"

Simon