Files
binutils-gdb/gdb/sparc64-fbsd-tdep.c
Simon Marchi a2e3cce344 gdb/solib: C++ify solib_ops
Convert solib_ops into an abstract base class (with abstract methods,
some of them with default implementations) and convert all the existing
solib_ops instances to solib_ops derived classes / implementations.

Prior to this patch, solib_ops is a structure holding function pointers,
of which there are only a handful of global instances (in the
`solib-*.c` files).  When passing an `solib_ops *` around, it's a
pointer to one of these instances.  After this patch, there are no more
global solib_ops instances.  Instances are created as needed and stored
in struct program_space.  These instances could eventually be made to
contain the program space-specific data, which is currently kept in
per-program space registries (I have some pending patches for that).

Prior to this patch, `gdbarch_so_ops` is a gdbarch method that returns a
pointer to the appropriate solib_ops implementation for the gdbarch.
This is replaced with the `gdbarch_make_solib_ops` method, which returns
a new instance of the appropriate solib_ops implementation for this
gdbarch.  This requires introducing some factory functions for the
various solib_ops implementation, to be used as `gdbarch_make_solib_ops`
callbacks.  For instance:

    solib_ops_up
    make_linux_ilp32_svr4_solib_ops ()
    {
      return std::make_unique<linux_ilp32_svr4_solib_ops> ();
    }

The previous code is full of cases of tdep files copying some base
solib_ops implementation, and overriding one or more function pointer
(see ppc_linux_init_abi, for instance).  I tried to convert all of this
is a class hierarchy.  I like that it's now possible to get a good
static view of all the existing solib_ops variants.  The hierarchy looks
like this:

    solib_ops
    ├── aix_solib_ops
    ├── darwin_solib_ops
    ├── dsbt_solib_ops
    ├── frv_solib_ops
    ├── rocm_solib_ops
    ├── svr4_solib_ops
    │   ├── ilp32_svr4_solib_ops
    │   ├── lp64_svr4_solib_ops
    │   ├── linux_ilp32_svr4_solib_ops
    │   │   ├── mips_linux_ilp32_svr4_solib_ops
    │   │   └── ppc_linux_ilp32_svr4_solib_ops
    │   ├── linux_lp64_svr4_solib_ops
    │   │   └── mips_linux_lp64_svr4_solib_ops
    │   ├── mips_nbsd_ilp32_svr4_solib_ops
    │   ├── mips_nbsd_lp64_svr4_solib_ops
    │   ├── mips_fbsd_ilp32_svr4_solib_ops
    │   └── mips_fbsd_lp64_svr4_solib_ops
    └── target_solib_ops
        └── windows_solib_ops

The solib-svr4 code has per-arch specialization to provide a
link_map_offsets, containing the offsets of the interesting fields in
`struct link_map` on that particular architecture.  Prior to this patch,
arches would set a callback returning the appropriate link_map_offsets
by calling `set_solib_svr4_fetch_link_map_offsets`, which also happened
to set the gdbarch's so_ops to `&svr_so_ops`.  I converted this to an
abstract virtual method of `struct svr4_solib_ops`, meaning that all
classes deriving from svr4_solib_ops must provide a method returning the
appropriate link_map_offsets for the architecture.  I renamed
`set_solib_svr4_fetch_link_map_offsets` to `set_solib_svr4_ops`.  This
function is still necessary because it also calls
set_gdbarch_iterate_over_objfiles_in_search_order, but if it was not for
that, we could get rid of it.

There is an instance of CRTP in mips-linux-tdep.c, because both
mips_linux_ilp32_svr4_solib_ops and mips_linux_lp64_svr4_solib_ops need
to derive from different SVR4 base classes (linux_ilp32_svr4_solib_ops
and linux_lp64_svr4_solib_ops), but they both want to override the
in_dynsym_resolve_code method with the same implementation.

The solib_ops::supports_namespaces method is new: the support for
namespaces was previously predicated by the presence or absence of a
find_solib_ns method.  It now needs to be explicit.

There is a new progspace::release_solib_ops method, which is only needed
for rocm_solib_ops.  For the moment, rocm_solib_ops replaces and wraps
the existing svr4_solib_ops instance, in order to combine the results of
the two.  The plan is to have a subsequent patch to allow program spaces to have
multiple solib_ops, removing the need for release_solib_ops.

Speaking of rocm_solib_ops: it previously overrode only a few methods by
copying svr4_solib_ops and overwriting some function pointers.  Now, it
needs to implement all the methods that svr4_solib_ops implements, in
order to forward the call.  Otherwise, the default solib_ops method
would be called, hiding the svr4_solib_ops implementation.  Again, this
can be removed once we have support for multiple solib_ops in a
program_space.

There is also a small change in how rocm_solib_ops is activated.  Prior
to this patch, it's done at the end of rocm_update_solib_list.  Since it
overrides the function pointer in the static svr4_solib_ops, and then
overwrites the host gdbarch, so_ops field, it's something that happens
only once.  After the patch though, we need to set rocm_solib_ops in all
the program spaces that appear.  We do this in
rocm_solib_target_inferior_created and in the new
rocm_solib_target_inferior_execd.  After this, I will explore doing a
change where rocm_solib_ops is only set when we detect the ROCm runtime
is loaded.

Change-Id: I5896b5bcbf8bdb024d67980380feba1ffefaa4c9
Approved-By: Pedro Alves <pedro@palves.net>
2025-06-26 14:08:31 -04:00

249 lines
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/* Target-dependent code for FreeBSD/sparc64.
Copyright (C) 2003-2025 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 "frame.h"
#include "frame-unwind.h"
#include "gdbcore.h"
#include "osabi.h"
#include "regcache.h"
#include "regset.h"
#include "target.h"
#include "trad-frame.h"
#include "sparc64-tdep.h"
#include "fbsd-tdep.h"
#include "solib-svr4.h"
#include "gdbarch.h"
/* From <machine/reg.h>. */
const struct sparc_gregmap sparc64fbsd_gregmap =
{
26 * 8, /* "tstate" */
25 * 8, /* %pc */
24 * 8, /* %npc */
28 * 8, /* %y */
16 * 8, /* %fprs */
-1,
1 * 8, /* %g1 */
-1, /* %l0 */
8 /* sizeof (%y) */
};
static void
sparc64fbsd_supply_gregset (const struct regset *regset,
struct regcache *regcache,
int regnum, const void *gregs, size_t len)
{
sparc64_supply_gregset (&sparc64fbsd_gregmap, regcache, regnum, gregs);
}
static void
sparc64fbsd_collect_gregset (const struct regset *regset,
const struct regcache *regcache,
int regnum, void *gregs, size_t len)
{
sparc64_collect_gregset (&sparc64fbsd_gregmap, regcache, regnum, gregs);
}
static void
sparc64fbsd_supply_fpregset (const struct regset *regset,
struct regcache *regcache,
int regnum, const void *fpregs, size_t len)
{
sparc64_supply_fpregset (&sparc64_bsd_fpregmap, regcache, regnum, fpregs);
}
static void
sparc64fbsd_collect_fpregset (const struct regset *regset,
const struct regcache *regcache,
int regnum, void *fpregs, size_t len)
{
sparc64_collect_fpregset (&sparc64_bsd_fpregmap, regcache, regnum, fpregs);
}
/* Signal trampolines. */
static int
sparc64fbsd_pc_in_sigtramp (CORE_ADDR pc, const char *name)
{
return (name && strcmp (name, "__sigtramp") == 0);
}
static struct sparc_frame_cache *
sparc64fbsd_sigtramp_frame_cache (const frame_info_ptr &this_frame,
void **this_cache)
{
struct sparc_frame_cache *cache;
CORE_ADDR addr, mcontext_addr, sp;
LONGEST fprs;
int regnum;
if (*this_cache)
return (struct sparc_frame_cache *) *this_cache;
cache = sparc_frame_cache (this_frame, this_cache);
gdb_assert (cache == *this_cache);
cache->saved_regs = trad_frame_alloc_saved_regs (this_frame);
/* The third argument is a pointer to an instance of `ucontext_t',
which has a member `uc_mcontext' that contains the saved
registers. */
addr = get_frame_register_unsigned (this_frame, SPARC_O2_REGNUM);
mcontext_addr = addr + 64;
/* The following registers travel in the `mc_local' slots of
`mcontext_t'. */
addr = mcontext_addr + 16 * 8;
cache->saved_regs[SPARC64_FPRS_REGNUM].set_addr (addr + 0 * 8);
cache->saved_regs[SPARC64_FSR_REGNUM].set_addr (addr + 1 * 8);
/* The following registers travel in the `mc_in' slots of
`mcontext_t'. */
addr = mcontext_addr + 24 * 8;
cache->saved_regs[SPARC64_NPC_REGNUM].set_addr (addr + 0 * 8);
cache->saved_regs[SPARC64_PC_REGNUM].set_addr (addr + 1 * 8);
cache->saved_regs[SPARC64_STATE_REGNUM].set_addr (addr + 2 * 8);
cache->saved_regs[SPARC64_Y_REGNUM].set_addr (addr + 4 * 8);
/* The `global' and `out' registers travel in the `mc_global' and
`mc_out' slots of `mcontext_t', except for %g0. Since %g0 is
always zero, keep the identity encoding. */
for (regnum = SPARC_G1_REGNUM, addr = mcontext_addr + 8;
regnum <= SPARC_O7_REGNUM; regnum++, addr += 8)
cache->saved_regs[regnum].set_addr (addr);
/* The `local' and `in' registers have been saved in the register
save area. */
addr = cache->saved_regs[SPARC_SP_REGNUM].addr ();
sp = get_frame_memory_unsigned (this_frame, addr, 8);
for (regnum = SPARC_L0_REGNUM, addr = sp + BIAS;
regnum <= SPARC_I7_REGNUM; regnum++, addr += 8)
cache->saved_regs[regnum].set_addr (addr);
/* The floating-point registers are only saved if the FEF bit in
%fprs has been set. */
#define FPRS_FEF (1 << 2)
addr = cache->saved_regs[SPARC64_FPRS_REGNUM].addr ();
fprs = get_frame_memory_unsigned (this_frame, addr, 8);
if (fprs & FPRS_FEF)
{
for (regnum = SPARC_F0_REGNUM, addr = mcontext_addr + 32 * 8;
regnum <= SPARC_F31_REGNUM; regnum++, addr += 4)
cache->saved_regs[regnum].set_addr (addr);
for (regnum = SPARC64_F32_REGNUM;
regnum <= SPARC64_F62_REGNUM; regnum++, addr += 8)
cache->saved_regs[regnum].set_addr (addr);
}
return cache;
}
static void
sparc64fbsd_sigtramp_frame_this_id (const frame_info_ptr &this_frame,
void **this_cache,
struct frame_id *this_id)
{
struct sparc_frame_cache *cache =
sparc64fbsd_sigtramp_frame_cache (this_frame, this_cache);
(*this_id) = frame_id_build (cache->base, cache->pc);
}
static struct value *
sparc64fbsd_sigtramp_frame_prev_register (const frame_info_ptr &this_frame,
void **this_cache, int regnum)
{
struct sparc_frame_cache *cache =
sparc64fbsd_sigtramp_frame_cache (this_frame, this_cache);
return trad_frame_get_prev_register (this_frame, cache->saved_regs, regnum);
}
static int
sparc64fbsd_sigtramp_frame_sniffer (const struct frame_unwind *self,
const frame_info_ptr &this_frame,
void **this_cache)
{
CORE_ADDR pc = get_frame_pc (this_frame);
const char *name;
find_pc_partial_function (pc, &name, NULL, NULL);
if (sparc64fbsd_pc_in_sigtramp (pc, name))
return 1;
return 0;
}
static const struct frame_unwind_legacy sparc64fbsd_sigtramp_frame_unwind (
"sparc64 freebsd sigtramp",
SIGTRAMP_FRAME,
FRAME_UNWIND_ARCH,
default_frame_unwind_stop_reason,
sparc64fbsd_sigtramp_frame_this_id,
sparc64fbsd_sigtramp_frame_prev_register,
NULL,
sparc64fbsd_sigtramp_frame_sniffer
);
static const struct regset sparc64fbsd_gregset =
{
NULL, sparc64fbsd_supply_gregset, sparc64fbsd_collect_gregset
};
static const struct regset sparc64fbsd_fpregset =
{
NULL, sparc64fbsd_supply_fpregset, sparc64fbsd_collect_fpregset
};
static void
sparc64fbsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
{
sparc_gdbarch_tdep *tdep = gdbarch_tdep<sparc_gdbarch_tdep> (gdbarch);
/* Generic FreeBSD support. */
fbsd_init_abi (info, gdbarch);
tdep->gregset = &sparc64fbsd_gregset;
tdep->sizeof_gregset = 256;
tdep->fpregset = &sparc64fbsd_fpregset;
tdep->sizeof_fpregset = 272;
frame_unwind_append_unwinder (gdbarch, &sparc64fbsd_sigtramp_frame_unwind);
sparc64_init_abi (info, gdbarch);
/* FreeBSD/sparc64 has SVR4-style shared libraries. */
set_gdbarch_skip_trampoline_code (gdbarch, find_solib_trampoline_target);
set_solib_svr4_ops (gdbarch, make_svr4_lp64_solib_ops);
}
INIT_GDB_FILE (sparc64fbsd_tdep)
{
gdbarch_register_osabi (bfd_arch_sparc, bfd_mach_sparc_v9,
GDB_OSABI_FREEBSD, sparc64fbsd_init_abi);
}