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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>
165 lines
4.6 KiB
C
165 lines
4.6 KiB
C
/* Target-dependent code for OpenBSD/mips64.
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Copyright (C) 2004-2024 Free Software Foundation, Inc.
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This file is part of GDB.
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 3 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program. If not, see <http://www.gnu.org/licenses/>. */
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#include "defs.h"
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#include "gdbtypes.h"
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#include "osabi.h"
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#include "regcache.h"
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#include "regset.h"
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#include "trad-frame.h"
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#include "tramp-frame.h"
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#include "obsd-tdep.h"
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#include "mips-tdep.h"
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#include "solib-svr4.h"
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#define MIPS64OBSD_NUM_REGS 73
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/* Core file support. */
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/* Supply register REGNUM from the buffer specified by GREGS and LEN
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in the general-purpose register set REGSET to register cache
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REGCACHE. If REGNUM is -1, do this for all registers in REGSET. */
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static void
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mips64obsd_supply_gregset (const struct regset *regset,
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struct regcache *regcache, int regnum,
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const void *gregs, size_t len)
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{
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const char *regs = (const char *) gregs;
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int i;
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for (i = 0; i < MIPS64OBSD_NUM_REGS; i++)
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{
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if (regnum == i || regnum == -1)
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regcache->raw_supply (i, regs + i * 8);
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}
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}
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/* OpenBSD/mips64 register set. */
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static const struct regset mips64obsd_gregset =
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{
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NULL,
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mips64obsd_supply_gregset
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};
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/* Iterate over core file register note sections. */
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static void
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mips64obsd_iterate_over_regset_sections (struct gdbarch *gdbarch,
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iterate_over_regset_sections_cb *cb,
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void *cb_data,
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const struct regcache *regcache)
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{
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cb (".reg", MIPS64OBSD_NUM_REGS * 8, MIPS64OBSD_NUM_REGS * 8,
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&mips64obsd_gregset, NULL, cb_data);
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}
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/* Signal trampolines. */
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static void
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mips64obsd_sigframe_init (const struct tramp_frame *self,
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const frame_info_ptr &this_frame,
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struct trad_frame_cache *cache,
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CORE_ADDR func)
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{
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struct gdbarch *gdbarch = get_frame_arch (this_frame);
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CORE_ADDR sp, sigcontext_addr, addr;
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int regnum;
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/* We find the appropriate instance of `struct sigcontext' at a
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fixed offset in the signal frame. */
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sp = get_frame_register_signed (this_frame,
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MIPS_SP_REGNUM + gdbarch_num_regs (gdbarch));
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sigcontext_addr = sp + 32;
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/* PC. */
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regnum = mips_regnum (gdbarch)->pc;
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trad_frame_set_reg_addr (cache,
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regnum + gdbarch_num_regs (gdbarch),
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sigcontext_addr + 16);
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/* GPRs. */
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for (regnum = MIPS_AT_REGNUM, addr = sigcontext_addr + 32;
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regnum <= MIPS_RA_REGNUM; regnum++, addr += 8)
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trad_frame_set_reg_addr (cache,
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regnum + gdbarch_num_regs (gdbarch),
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addr);
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/* HI and LO. */
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regnum = mips_regnum (gdbarch)->lo;
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trad_frame_set_reg_addr (cache,
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regnum + gdbarch_num_regs (gdbarch),
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sigcontext_addr + 280);
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regnum = mips_regnum (gdbarch)->hi;
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trad_frame_set_reg_addr (cache,
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regnum + gdbarch_num_regs (gdbarch),
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sigcontext_addr + 288);
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/* TODO: Handle the floating-point registers. */
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trad_frame_set_id (cache, frame_id_build (sp, func));
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}
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static const struct tramp_frame mips64obsd_sigframe =
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{
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SIGTRAMP_FRAME,
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MIPS_INSN32_SIZE,
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{
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{ 0x67a40020, ULONGEST_MAX }, /* daddiu a0,sp,32 */
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{ 0x24020067, ULONGEST_MAX }, /* li v0,103 */
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{ 0x0000000c, ULONGEST_MAX }, /* syscall */
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{ 0x0000000d, ULONGEST_MAX }, /* break */
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{ TRAMP_SENTINEL_INSN, ULONGEST_MAX }
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},
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mips64obsd_sigframe_init
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};
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static void
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mips64obsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
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{
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/* OpenBSD/mips64 only supports the n64 ABI, but the braindamaged
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way GDB works, forces us to pretend we can handle them all. */
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set_gdbarch_iterate_over_regset_sections
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(gdbarch, mips64obsd_iterate_over_regset_sections);
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tramp_frame_prepend_unwinder (gdbarch, &mips64obsd_sigframe);
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set_gdbarch_long_double_bit (gdbarch, 128);
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set_gdbarch_long_double_format (gdbarch, floatformats_ieee_quad);
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obsd_init_abi(info, gdbarch);
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/* OpenBSD/mips64 has SVR4-style shared libraries. */
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set_solib_svr4_fetch_link_map_offsets
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(gdbarch, svr4_lp64_fetch_link_map_offsets);
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}
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void _initialize_mips64obsd_tdep ();
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void
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_initialize_mips64obsd_tdep ()
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{
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gdbarch_register_osabi (bfd_arch_mips, 0, GDB_OSABI_OPENBSD,
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mips64obsd_init_abi);
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}
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