C++ify xmethod_worker, get rid of VEC(xmethod_worker_ptr)
authorSimon Marchi <simon.marchi@polymtl.ca>
Sun, 7 Jan 2018 14:25:32 +0000 (09:25 -0500)
committerSimon Marchi <simon.marchi@ericsson.com>
Sun, 7 Jan 2018 14:25:32 +0000 (09:25 -0500)
commitba18742c3a1b62ff218db99bee47bb932af6dab9
tree14680d97dbbc56e326a6b2bda0bb1ba25dbd6970
parentd672364615e87e8c366b536940f269fdc3141330
C++ify xmethod_worker, get rid of VEC(xmethod_worker_ptr)

The initial goal of this patch was to remove the usage of
VEC(xmethod_worker_ptr) and corresponding cleanups.  I ended up having
to  C++ify the xmethod_worker code, to be able to have xmethod_workers
free their data in destructors, and therefore be able to use vectors of
xmethod_worker unique_ptr.

The operations in extension_language_ops that act on one instance of
xmethod_worker (get result type, get args type, invoke) are transformed
to methods of xmethod_worker.  xmethod_worker becomes an abstract base
class with virtual pure methods which python_xmethod_worker implements.
The only xmethod-related operation left in extension_language_ops is
get_matching_xmethod_workers, which returns a list of xmethod_workers.

The changes are relatively straightforward, but here are some notes on
things that may raise eyebrows:

  - I was not really comfortable with the value_of_xmethod function.  At
  first it looks like a simple getter, so I considered making it a
  method of xmethod_worker.  But actually it creates a value and
  transfers the ownership of the xmethod_worker to it.  It would be a
  bit weird and error-prone if calling a method on an object silently
  removed the ownership of the object from the caller.  To reflect the
  behavior more accurately, I renamed it to value_from_xmethod and made
  it accept an rvalue-reference (so the caller knows it gives away the
  ownership).  I noticed the backlink from xmethod_worker to its owning
  value was not used, so I removed it.

  - Some code, like get_matching_xmethod_workers, made each callee fill
  a new vector, which was then merged in the result vector.  I think
  it's safe if we always pass the same vector around, and each
  implementation just appends to it.

  - The clone operation does not seem particularly useful, it is removed
  in the following patch.

gdb/ChangeLog:

* extension-priv.h (enum ext_lang_rc): Remove, move to extension.h.
(struct extension_language_ops) <clone_xmethod_worker_data>: Remove.
<free_xmethod_worker_data>: Remove.
<get_matching_xmethod_workers>: Chance VEC to std::vector.
<get_xmethod_arg_types>: Remove.
<get_xmethod_result_type>: Remove.
<invoke_xmethod>: Remove.
* extension.c (new_xmethod_worker): Remove.
(clone_xmethod_worker): Remove.
(get_matching_xmethod_workers): Return void, pass std::vector by
pointer.
(get_xmethod_arg_types): Rename to...
(xmethod_worker::get_arg_types): ... this, and adjust.
(get_xmethod_result_type): Rename to...
(xmethod_worker::get_result_type): ... this, and adjust.
(invoke_xmethod): Remove.
(free_xmethod_worker): Remove.
(free_xmethod_worker_vec): Remove.
* extension.h (enum ext_lang_rc): Move here from
extension-priv.h.
(struct xmethod_worker): Add constructor and destructor.
<data>: Remove.
<value>: Remove.
<invoke, clone, do_get_result_type, do_get_arg_types>: New
virtual pure methods.
<get_arg_types, get_result_type>: New methods.
(xmethod_worker_ptr): Remove typedef.
(DEF_VEC_P (xmethod_worker_ptr)): Remove.
(xmethod_worker_vec): Remove typedef.
(xmethod_worker_up): New typedef.
(invoke_xmethod): Remove.
(clone_xmethod_worker): Remove.
(free_xmethod_worker): Remove.
(free_xmethod_worker_vec): Remove.
(get_xmethod_arg_types): Remove.
(get_xmethod_result_type): Remove.
* valops.c (find_method_list): Use std::vector, don't use
intermediate vector.
(value_find_oload_method_list): Use std::vector.
(find_overload_match): Use std::vector.
(find_oload_champ): Use std::vector.
* value.c (value_free): Use operator delete.
(value_of_xmethod): Rename to...
(value_from_xmethod): ... this.  Don't assign
xmethod_worker::value, take rvalue-reference.
(result_type_of_xmethod): Adjust.
(call_xmethod): Adjust.
* value.h: Include extension.h.
(struct xmethod_worker): Don't forward-declare.
(value_of_xmethod): Rename to...
(value_from_xmethod): ... this, take rvalue-reference.
* python/py-xmethods.c (struct gdbpy_worker_data): Rename to...
(struct python_xmethod_worker): ... this, add constructor and
destructor.
<invoke, clone, do_get_arg_types, do_get_result_type>: Implement.
(gdbpy_free_xmethod_worker_data): Rename to...
(python_xmethod_worker::~python_xmethod_worker): ... this and
adjust.
(gdbpy_clone_xmethod_worker_data): Rename to...
(python_xmethod_worker::clone): ... this and adjust.
(gdbpy_get_matching_xmethod_workers): Use std::vector, don't use
temporary vector.
(gdbpy_get_xmethod_arg_types): Rename to...
(python_xmethod_worker::do_get_arg_types): ... this and adjust.
(gdbpy_get_xmethod_result_type): Rename to...
(python_xmethod_worker::do_get_result_type): ... this and
adjust.
(gdbpy_invoke_xmethod): Rename to...
(python_xmethod_worker::invoke): ... this and adjust.
(new_python_xmethod_worker): Rename to...
(python_xmethod_worker::python_xmethod_worker): ... this and
adjust.
* python/python-internal.h (gdbpy_clone_xmethod_worker_data):
Remove.
(gdbpy_free_xmethod_worker_data): Remove.
(gdbpy_get_matching_xmethod_workers): Use std::vector.
(gdbpy_get_xmethod_arg_types): Remove.
(gdbpy_get_xmethod_result_type): Remove.
(gdbpy_invoke_xmethod): Remove.
* python/python.c (python_extension_ops): Remove obsolete
callbacks.
gdb/ChangeLog
gdb/extension-priv.h
gdb/extension.c
gdb/extension.h
gdb/python/py-xmethods.c
gdb/python/python-internal.h
gdb/python/python.c
gdb/valops.c
gdb/value.c
gdb/value.h