Files
binutils-gdb/gdb/amd-dbgapi-target.h
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

122 lines
3.7 KiB
C++

/* Target used to communicate with the AMD Debugger API.
Copyright (C) 2019-2025 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/>. */
#ifndef GDB_AMD_DBGAPI_TARGET_H
#define GDB_AMD_DBGAPI_TARGET_H
#include "gdbsupport/observable.h"
#include <amd-dbgapi/amd-dbgapi.h>
struct inferior;
namespace detail
{
template <typename T>
using is_amd_dbgapi_handle
= gdb::Or<std::is_same<T, amd_dbgapi_address_class_id_t>,
std::is_same<T, amd_dbgapi_address_space_id_t>,
std::is_same<T, amd_dbgapi_architecture_id_t>,
std::is_same<T, amd_dbgapi_agent_id_t>,
std::is_same<T, amd_dbgapi_breakpoint_id_t>,
std::is_same<T, amd_dbgapi_code_object_id_t>,
std::is_same<T, amd_dbgapi_dispatch_id_t>,
std::is_same<T, amd_dbgapi_displaced_stepping_id_t>,
std::is_same<T, amd_dbgapi_event_id_t>,
std::is_same<T, amd_dbgapi_process_id_t>,
std::is_same<T, amd_dbgapi_queue_id_t>,
std::is_same<T, amd_dbgapi_register_class_id_t>,
std::is_same<T, amd_dbgapi_register_id_t>,
std::is_same<T, amd_dbgapi_watchpoint_id_t>,
std::is_same<T, amd_dbgapi_wave_id_t>>;
} /* namespace detail */
/* Get the token of amd-dbgapi's inferior_created observer. */
const gdb::observers::token &
get_amd_dbgapi_target_inferior_created_observer_token ();
/* Get the token of amd-dbgapi's inferior_execd observer. */
const gdb::observers::token &
get_amd_dbgapi_target_inferior_execd_observer_token ();
/* Comparison operators for amd-dbgapi handle types. */
template <typename T,
typename = gdb::Requires<detail::is_amd_dbgapi_handle<T>>>
bool
operator== (const T &lhs, const T &rhs)
{
return lhs.handle == rhs.handle;
}
template <typename T,
typename = gdb::Requires<detail::is_amd_dbgapi_handle<T>>>
bool
operator!= (const T &lhs, const T &rhs)
{
return !(lhs == rhs);
}
/* Return true if the given ptid is a GPU thread (wave) ptid. */
static inline bool
ptid_is_gpu (ptid_t ptid)
{
/* FIXME: Currently using values that are known not to conflict with other
processes to indicate if it is a GPU thread. ptid.pid 1 is the init
process and is the only process that could have a ptid.lwp of 1. The init
process cannot have a GPU. No other process can have a ptid.lwp of 1.
The GPU wave ID is stored in the ptid.tid. */
return ptid.pid () != 1 && ptid.lwp () == 1;
}
/* Return INF's amd_dbgapi process id. */
amd_dbgapi_process_id_t get_amd_dbgapi_process_id (inferior *inf);
/* Get the amd-dbgapi wave id for PTID. */
static inline amd_dbgapi_wave_id_t
get_amd_dbgapi_wave_id (ptid_t ptid)
{
gdb_assert (ptid_is_gpu (ptid));
return amd_dbgapi_wave_id_t {
static_cast<decltype (amd_dbgapi_wave_id_t::handle)> (ptid.tid ())
};
}
/* Get the textual version of STATUS.
Always returns non-nullptr, and asserts that STATUS has a valid value. */
static inline const char *
get_status_string (amd_dbgapi_status_t status)
{
const char *ret;
status = amd_dbgapi_get_status_string (status, &ret);
gdb_assert (status == AMD_DBGAPI_STATUS_SUCCESS);
return ret;
}
#endif /* GDB_AMD_DBGAPI_TARGET_H */