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Re: [PATCH 4/5] Make Python inferior-related internal functions return a gdbpy_inf_ref
- From: Simon Marchi <simon dot marchi at polymtl dot ca>
- To: Pedro Alves <palves at redhat dot com>
- Cc: Simon Marchi <simon dot marchi at ericsson dot com>, gdb-patches at sourceware dot org, Tom Tromey <tom at tromey dot com>
- Date: Thu, 09 Feb 2017 11:39:22 -0500
- Subject: Re: [PATCH 4/5] Make Python inferior-related internal functions return a gdbpy_inf_ref
- Authentication-results: sourceware.org; auth=none
- References: <20170123224004.8893-1-simon.marchi@ericsson.com> <20170123224004.8893-5-simon.marchi@ericsson.com> <0bf1c645-7efb-4348-feee-5c848f71fee8@redhat.com>
Thanks for the comments. I'll update my branch, but I'll wait until
Tom's series is pushed and see what's still relevant in mine.
On 2017-02-09 07:30, Pedro Alves wrote:
@@ -207,39 +207,38 @@ python_new_objfile (struct objfile *objfile)
representing INFERIOR. If the object has already been created,
return it and increment the reference count, otherwise, create
it.
Return NULL on failure. */
-inferior_object *
+gdbpy_inf_ref
inferior_to_inferior_object (struct inferior *inferior)
{
...
- if (!inf_obj)
- return NULL;
+ if (inf_obj == NULL)
+ return gdbpy_inf_ref ();
You shouldn't need changes like this one. gdbpy_ref has an
implicit ctor that takes nullptr_t exactly to allow implicit
construction from null.
Ok. This required adding the corresponding constructor in
gdbpy_ref_base:
gdbpy_ref_base (const std::nullptr_t)
: gdb::ref_ptr<T, gdbpy_ref_policy<T>> (nullptr)
{
}
/* Find thread entry in its inferior's thread_list. */
- for (entry = &inf_obj->threads; *entry != NULL; entry =
- &(*entry)->next)
+ for (entry = &inf_obj_ref.get ()->threads;
Hmm, changes like these are odd. gdbpy_ref has an operator->
implementation, so inf_obj->threads should do the right thing?
Hmm you're right, not sure why I added those.
@@ -815,7 +809,10 @@ py_free_inferior (struct inferior *inf, void
*datum)
PyObject *
gdbpy_selected_inferior (PyObject *self, PyObject *args)
{
- return (PyObject *) inferior_to_inferior_object (current_inferior
());
+ gdbpy_inf_ref inf_obj_ref (inferior_to_inferior_object
(current_inferior ()));
If the function returns gdbpy_inf_ref already, I much prefer
using = initialization over (), like:
gdbpy_inf_ref inf_obj_ref
= inferior_to_inferior_object (current_inferior ());
The reason is that this makes it more obvious what is going on.
The ctor taking a PyObject* is explicit so inferior_to_inferior_object
must be returning a gdbpy_inf_ref.
With:
gdbpy_inf_ref inf_obj_ref (inferior_to_inferior_object
(current_inferior ()));
one has to wonder what constructor is being called, and whether there's
some kind of explicit conversion going on.
So the = version is more to the point and thus makes it
for a clearer read because there's less to reason about.
Right, it's more obvious.
Thanks,
Simon