[PATCH 0/4] Add support for command renaming

[Marco Barisione via Gdb-patches <gdb-patches@sourceware.org>]

This patch series adds support for command renaming to GDB.  The main
use case is to extend existing commands:
* The original command gets renamed.
* A new command with the same original name gets defined and then calls
  the renamed one.

This feature is accessible via GDB commands ("rename" and
"define -rename-existing-to") and in Python via a new rename_existing_to
argument argument to gdb.Command.__init__.

This is the third attempt at achieving this, the first patch series (see
https://sourceware.org/legacy-ml/gdb-patches/2019-10/msg00985.html) used
a completely different approach where a command, once overwritten, was
preserved by the new command (via a new field in cmd_list_element).
Overwriting commands could access the original implementation via a
Python method on gdb.Command.

The second attempt (see
https://sourceware.org/pipermail/gdb-patches/2020-September/171829.html)
was a revised version of the previous one which worked in a similar way,
but using a slightly different terminology.  It also added a way to
access this feature via a GDB command, not only via Python.

In response to my patches, Pedro Alves recommended a different approach
involving command renaming, which is what I implemented here.

Note that I didn't use "v3" in these patches are the approach is
completely different from previous attempts, so it's not really a new
version of already proposed patches (even if the end goal of this
feature is the same).

Marco Barisione (4):
  gdb: add lookup_cmd_exact to simplify a common pattern
  gdb: prevent prefix commands from being hooks
  gdb: update the docs for add_cmd and do_add_cmd to match reality
  gdb: Add support for renaming commands

 gdb/NEWS                                      |  26 +
 gdb/cli/cli-decode.c                          | 708 +++++++++++++++---
 gdb/cli/cli-decode.h                          |   3 +
 gdb/cli/cli-script.c                          | 368 +++++++--
 gdb/command.h                                 | 103 ++-
 gdb/doc/gdb.texinfo                           |  55 +-
 gdb/doc/python.texi                           |  38 +-
 gdb/python/py-cmd.c                           | 172 ++++-
 gdb/testsuite/gdb.base/command-renaming.exp   | 571 ++++++++++++++
 gdb/testsuite/gdb.base/define-prefix.exp      |  24 +
 .../gdb.python/py-rename-existing.exp         | 364 +++++++++
 .../gdb.python/py-rename-existing.py          |  46 ++
 12 files changed, 2238 insertions(+), 240 deletions(-)
 create mode 100644 gdb/testsuite/gdb.base/command-renaming.exp
 create mode 100644 gdb/testsuite/gdb.python/py-rename-existing.exp
 create mode 100644 gdb/testsuite/gdb.python/py-rename-existing.py

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2.28.0