mirror of
https://sourceware.org/git/binutils-gdb.git
synced 2025-01-06 12:09:26 +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>
89 lines
2.4 KiB
C
89 lines
2.4 KiB
C
/* Target-dependent code for i386 BSD's.
|
||
|
||
Copyright (C) 2001-2024 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/>. */
|
||
|
||
#include "defs.h"
|
||
#include "arch-utils.h"
|
||
#include "frame.h"
|
||
#include "gdbcore.h"
|
||
#include "regcache.h"
|
||
#include "osabi.h"
|
||
|
||
#include "i386-tdep.h"
|
||
|
||
/* Support for signal handlers. */
|
||
|
||
/* Assuming THIS_FRAME is for a BSD sigtramp routine, return the
|
||
address of the associated sigcontext structure. */
|
||
|
||
static CORE_ADDR
|
||
i386bsd_sigcontext_addr (const frame_info_ptr &this_frame)
|
||
{
|
||
struct gdbarch *gdbarch = get_frame_arch (this_frame);
|
||
enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
|
||
gdb_byte buf[4];
|
||
CORE_ADDR sp;
|
||
|
||
get_frame_register (this_frame, I386_ESP_REGNUM, buf);
|
||
sp = extract_unsigned_integer (buf, 4, byte_order);
|
||
|
||
return read_memory_unsigned_integer (sp + 8, 4, byte_order);
|
||
}
|
||
|
||
|
||
/* Support for shared libraries. */
|
||
|
||
/* Traditional BSD (4.3 BSD, still used for BSDI and 386BSD). */
|
||
|
||
/* From <machine/signal.h>. */
|
||
int i386bsd_sc_reg_offset[] =
|
||
{
|
||
-1, /* %eax */
|
||
-1, /* %ecx */
|
||
-1, /* %edx */
|
||
-1, /* %ebx */
|
||
8 + 0 * 4, /* %esp */
|
||
8 + 1 * 4, /* %ebp */
|
||
-1, /* %esi */
|
||
-1, /* %edi */
|
||
8 + 3 * 4, /* %eip */
|
||
8 + 4 * 4, /* %eflags */
|
||
-1, /* %cs */
|
||
-1, /* %ss */
|
||
-1, /* %ds */
|
||
-1, /* %es */
|
||
-1, /* %fs */
|
||
-1 /* %gs */
|
||
};
|
||
|
||
void
|
||
i386bsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
|
||
{
|
||
i386_gdbarch_tdep *tdep = gdbarch_tdep<i386_gdbarch_tdep> (gdbarch);
|
||
|
||
tdep->jb_pc_offset = 0;
|
||
|
||
tdep->sigtramp_start = 0xfdbfdfc0;
|
||
tdep->sigtramp_end = 0xfdbfe000;
|
||
tdep->sigcontext_addr = i386bsd_sigcontext_addr;
|
||
tdep->sc_reg_offset = i386bsd_sc_reg_offset;
|
||
tdep->sc_num_regs = ARRAY_SIZE (i386bsd_sc_reg_offset);
|
||
}
|
||
|
||
|