mirror of
https://sourceware.org/git/binutils-gdb.git
synced 2024-11-23 01:53:38 +08:00
8480a37e14
We currently pass frames to function by value, as `frame_info_ptr`.
This is somewhat expensive:
- the size of `frame_info_ptr` is 64 bytes, which is a bit big to pass
by value
- the constructors and destructor link/unlink the object in the global
`frame_info_ptr::frame_list` list. This is an `intrusive_list`, so
it's not so bad: it's just assigning a few points, there's no memory
allocation as if it was `std::list`, but still it's useless to do
that over and over.
As suggested by Tom Tromey, change many function signatures to accept
`const frame_info_ptr &` instead of `frame_info_ptr`.
Some functions reassign their `frame_info_ptr` parameter, like:
void
the_func (frame_info_ptr frame)
{
for (; frame != nullptr; frame = get_prev_frame (frame))
{
...
}
}
I wondered what to do about them, do I leave them as-is or change them
(and need to introduce a separate local variable that can be
re-assigned). I opted for the later for consistency. It might not be
clear why some functions take `const frame_info_ptr &` while others take
`frame_info_ptr`. Also, if a function took a `frame_info_ptr` because
it did re-assign its parameter, I doubt that we would think to change it
to `const frame_info_ptr &` should the implementation change such that
it doesn't need to take `frame_info_ptr` anymore. It seems better to
have a simple rule and apply it everywhere.
Change-Id: I59d10addef687d157f82ccf4d54f5dde9a963fd0
Approved-By: Andrew Burgess <aburgess@redhat.com>
92 lines
3.2 KiB
C++
92 lines
3.2 KiB
C++
/* Definitions for a frame base, for GDB, the GNU debugger.
|
|
|
|
Copyright (C) 2003-2024 Free Software Foundation, Inc.
|
|
|
|
This file is part of GDB.
|
|
|
|
This program is free software; you can redistribute it and/or modify
|
|
it under the terms of the GNU General Public License as published by
|
|
the Free Software Foundation; either version 3 of the License, or
|
|
(at your option) any later version.
|
|
|
|
This program is distributed in the hope that it will be useful,
|
|
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
GNU General Public License for more details.
|
|
|
|
You should have received a copy of the GNU General Public License
|
|
along with this program. If not, see <http://www.gnu.org/licenses/>. */
|
|
|
|
#if !defined (FRAME_BASE_H)
|
|
#define FRAME_BASE_H 1
|
|
|
|
class frame_info_ptr;
|
|
struct frame_id;
|
|
struct frame_unwind;
|
|
struct frame_base;
|
|
struct gdbarch;
|
|
struct regcache;
|
|
|
|
/* Assuming the frame chain: (outer) prev <-> this <-> next (inner);
|
|
and that this is a `normal frame'; use THIS frame, and implicitly
|
|
the NEXT frame's register unwind method, to determine the address
|
|
of THIS frame's `base'.
|
|
|
|
The exact meaning of `base' is highly dependant on the type of the
|
|
debug info. It is assumed that dwarf2, stabs, ... will each
|
|
provide their own methods.
|
|
|
|
A typical implementation will return the same value for base,
|
|
locals-base and args-base. That value, however, will likely be
|
|
different to the frame ID's stack address. */
|
|
|
|
/* A generic base address. */
|
|
|
|
typedef CORE_ADDR (frame_this_base_ftype) (const frame_info_ptr &this_frame,
|
|
void **this_base_cache);
|
|
|
|
/* The base address of the frame's local variables. */
|
|
|
|
typedef CORE_ADDR (frame_this_locals_ftype) (const frame_info_ptr &this_frame,
|
|
void **this_base_cache);
|
|
|
|
/* The base address of the frame's arguments / parameters. */
|
|
|
|
typedef CORE_ADDR (frame_this_args_ftype) (const frame_info_ptr &this_frame,
|
|
void **this_base_cache);
|
|
|
|
struct frame_base
|
|
{
|
|
/* If non-NULL, a low-level unwinder that shares its implementation
|
|
with this high-level frame-base method. */
|
|
const struct frame_unwind *unwind;
|
|
frame_this_base_ftype *this_base;
|
|
frame_this_locals_ftype *this_locals;
|
|
frame_this_args_ftype *this_args;
|
|
};
|
|
|
|
/* Given THIS frame, return the frame base methods for THIS frame,
|
|
or NULL if it can't handle THIS frame. */
|
|
|
|
typedef const struct frame_base *(frame_base_sniffer_ftype) (const frame_info_ptr &this_frame);
|
|
|
|
/* Append a frame base sniffer to the list. The sniffers are polled
|
|
in the order that they are appended. */
|
|
|
|
extern void frame_base_append_sniffer (struct gdbarch *gdbarch,
|
|
frame_base_sniffer_ftype *sniffer);
|
|
|
|
/* Set the default frame base. If all else fails, this one is
|
|
returned. If this isn't set, the default is to use legacy code
|
|
that uses things like the frame ID's base (ulgh!). */
|
|
|
|
extern void frame_base_set_default (struct gdbarch *gdbarch,
|
|
const struct frame_base *def);
|
|
|
|
/* Iterate through the list of frame base handlers until one returns
|
|
an implementation. */
|
|
|
|
extern const struct frame_base *frame_base_find_by_frame (const frame_info_ptr &this_frame);
|
|
|
|
#endif
|