binutils-gdb/gdb/inf-child.h
Pedro Alves d9f719f1ad target factories, target open and multiple instances of targets
Currently, to open a target, with "target TARGET_NAME", GDB finds the
target_ops instance with "TARGET_NAME" as short name, and then calls
its target_ops::open virtual method.  In reality, there's no actual
target/name lookup, a pointer to the target_ops object was associated
with the "target TARGET_NAME" command at add_target time (when GDB is
initialized), as the command's context.

This creates a chicken and egg situation.  Consider the case of
wanting to open multiple remote connections.  We want to be able to
have one remote target_ops instance per connection, but, if we're not
connected yet, so we don't yet have an instance to call target->open()
on...

This patch fixes this by separating out common info about a target_ops
to a separate structure (shortname, longname, doc), and changing the
add_target routine to take a reference to such an object instead of a
pointer to a target_ops, and a pointer to a factory function that is
responsible to open an instance of the corresponding target when the
user types "target TARGET_NAME".

 -extern void add_target (struct target_ops *);
 +extern void add_target (const target_info &info, target_open_ftype *func);

I.e. this factory function replaces the target_ops::open virtual
method.

For static/singleton targets, nothing changes, the target_open_ftype
function pushes the global target_ops instance on the target stack.
At target_close time, the connection is tor down, but the global
target_ops object remains live.

However, targets that support being open multiple times will make
their target_open_ftype routine allocate a new target_ops instance on
the heap [e.g., new remote_target()], and push that on the stack.  At
target_close time, the new object is destroyed (by the
target_ops::close virtual method).

Both the core target and the remote targets will support being open
multiple times (others could/should too, but those were my stopping
point), but not in this patch yet.  We need to get rid of more globals
first before that'd be useful.

Native targets are somewhat special, given find_default_run_target &
friends.  Those routines also expect to return a target_ops pointer,
even before we've open the target.  However, we'll never need more
than one instance of the native target, so we can assume/require that
native targets are global/simpletons, and have the backends register a
pointer to the native target_ops.  Since all native targets inherit
inf_child_target, we can centralize that registration.  See
add_inf_child_target, get_native_target/set_native_target and
find_default_run_target.

gdb/ChangeLog:
2018-05-02  Pedro Alves  <palves@redhat.com>

	* aarch64-fbsd-nat.c (_initialize_aarch64_fbsd_nat): Use
	add_inf_child_target.
	* aarch64-linux-nat.c (_initialize_aarch64_linux_nat): Use
	add_inf_child_target.
	* aix-thread.c (aix_thread_target_info): New.
	(aix_thread_target) <shortname, longname, doc>: Delete.
	<info>: New.
	* alpha-bsd-nat.c (_initialize_alphabsd_nat): Use
	add_inf_child_target.
	* alpha-linux-nat.c (_initialize_alpha_linux_nat): Use
	add_inf_child_target.
	* amd64-fbsd-nat.c (_initialize_amd64fbsd_nat): Use
	add_inf_child_target.
	* amd64-linux-nat.c (_initialize_amd64_linux_nat): Use
	add_inf_child_target.
	* amd64-nbsd-nat.c (_initialize_amd64nbsd_nat): Use
	add_inf_child_target.
	* amd64-obsd-nat.c (_initialize_amd64obsd_nat): Use
	add_inf_child_target.
	* arm-fbsd-nat.c (_initialize_arm_fbsd_nat): Use
	add_inf_child_target.
	* arm-linux-nat.c (_initialize_arm_linux_nat): Use
	add_inf_child_target.
	* arm-nbsd-nat.c (_initialize_arm_netbsd_nat): Use
	add_inf_child_target.
	* bfd-target.c (target_bfd_target_info): New.
	(target_bfd) <shortname, longname, doc>: Delete.
	<info>: New.
	* bsd-kvm.c (bsd_kvm_target_info): New.
	(bsd_kvm_target) <shortname, longname, doc>: Delete.
	<info>: New.
	(bsd_kvm_target::open): Rename to ...
	(bsd_kvm_target_open): ... this.  Adjust.
	* bsd-uthread.c (bsd_uthread_target_info): New.
	(bsd_uthread_target) <shortname, longname, doc>: Delete.
	<info>:	New.
	* corefile.c (core_file_command): Adjust.
	* corelow.c (core_target_info): New.
	(core_target) <shortname, longname, doc>: Delete.
	<info>: New.
	(core_target::open): Rename to ...
	(core_target_open): ... this.  Adjust.
	* ctf.c (ctf_target_info): New.
	(ctf_target) <shortname, longname, doc>: Delete.
	<info>:	New.
	(ctf_target::open): Rename to ...
	(ctf_target_open): ... this.
	(_initialize_ctf): Adjust.
	* exec.c (exec_target_info): New.
	(exec_target) <shortname, longname, doc>: Delete.
	<info>:	New.
	(exec_target::open): Rename to ...
	(exec_target_open): ... this.
	* gdbcore.h (core_target_open): Declare.
	* go32-nat.c (_initialize_go32_nat): Use add_inf_child_target.
	* hppa-linux-nat.c (_initialize_hppa_linux_nat): Use
	add_inf_child_target.
	* hppa-nbsd-nat.c (_initialize_hppanbsd_nat): Use
	add_inf_child_target.
	* hppa-obsd-nat.c (_initialize_hppaobsd_nat): Use
	add_inf_child_target.
	* i386-darwin-nat.c (_initialize_i386_darwin_nat): Use
	add_inf_child_target.
	* i386-fbsd-nat.c (_initialize_i386fbsd_nat): Use
	add_inf_child_target.
	* i386-gnu-nat.c (_initialize_i386gnu_nat): Use
	add_inf_child_target.
	* i386-linux-nat.c (_initialize_i386_linux_nat): Use
	add_inf_child_target.
	* i386-nbsd-nat.c (_initialize_i386nbsd_nat): Use
	add_inf_child_target.
	* i386-obsd-nat.c (_initialize_i386obsd_nat): Use
	add_inf_child_target.
	* ia64-linux-nat.c (_initialize_ia64_linux_nat): Use
	add_inf_child_target.
	* inf-child.c (inf_child_target_info): New.
	(inf_child_target::info): New.
	(inf_child_open_target): Remove 'target' parameter.  Use
	get_native_target instead.
	(inf_child_target::open): Delete.
	(add_inf_child_target): New.
	* inf-child.h (inf_child_target) <shortname, longname, doc, open>:
	Delete.
	<info>:	New.
	(add_inf_child_target): Declare.
	(inf_child_open_target): Declare.
	* linux-thread-db.c (thread_db_target_info): New.
	(thread_db_target) <shortname, longname, doc>: Delete.
	<info>:	New.
	* m32r-linux-nat.c (_initialize_m32r_linux_nat): Use
	add_inf_child_target.
	* m68k-bsd-nat.c (_initialize_m68kbsd_nat): Use
	add_inf_child_target.
	* m68k-linux-nat.c (_initialize_m68k_linux_nat): Use
	add_inf_child_target.
	* m88k-bsd-nat.c (_initialize_m88kbsd_nat): Use
	add_inf_child_target.
	* make-target-delegates (print_class): Adjust.
	* mips-fbsd-nat.c (_initialize_mips_fbsd_nat): Use
	add_inf_child_target.
	* mips-linux-nat.c (_initialize_mips_linux_nat): Use
	add_inf_child_target.
	* mips-nbsd-nat.c (_initialize_mipsnbsd_nat): Use
	add_inf_child_target.
	* mips64-obsd-nat.c (_initialize_mips64obsd_nat): Use
	add_inf_child_target.
	* nto-procfs.c (nto_native_target_info): New.
	(nto_procfs_target_native) <shortname, longname, doc>:
	Delete.
	<info>:	New.
	(nto_procfs_target_info): New.
	(nto_procfs_target_procfs) <shortname, longname, doc>:
	Delete.
	<info>:	New.
	(init_procfs_targets): Adjust.
	* ppc-fbsd-nat.c (_initialize_ppcfbsd_nat): Use
	add_inf_child_target.
	* ppc-linux-nat.c (_initialize_ppc_linux_nat): Use
	add_inf_child_target.
	* ppc-nbsd-nat.c (_initialize_ppcnbsd_nat): Use
	add_inf_child_target.
	* ppc-obsd-nat.c (_initialize_ppcobsd_nat): Use
	add_inf_child_target.
	* ravenscar-thread.c (ravenscar_target_info): New.
	(ravenscar_thread_target) <shortname, longname, doc>:
	Delete.
	<info>:	New.
	* record-btrace.c (record_btrace_target_info):
	(record_btrace_target) <shortname, longname, doc>: Delete.
	<info>: New.
	(record_btrace_target::open): Rename to ...
	(record_btrace_target_open): ... this.  Adjust.
	* record-full.c (record_longname, record_doc): New.
	(record_full_base_target) <shortname, longname, doc>: Delete.
	<info>: New.
	(record_full_target_info): New.
	(record_full_target): <shortname>: Delete.
	<info>: New.
	(record_full_core_open_1, record_full_open_1): Update comments.
	(record_full_base_target::open): Rename to ...
	(record_full_open): ... this.
	(cmd_record_full_restore): Update.
	(_initialize_record_full): Update.
	* remote-sim.c (remote_sim_target_info): New.
	(gdbsim_target) <shortname, longname, doc>: Delete.
	<info>: New.
	(gdbsim_target::open): Rename to ...
	(gdbsim_target_open): ... this.
	(_initialize_remote_sim): Adjust.
	* remote.c (remote_doc): New.
	(remote_target_info): New.
	(remote_target) <shortname, longname, doc>: Delete.
	<info>: New.
	(extended_remote_target_info): New.
	(extended_remote_target) <shortname, longname, doc>: Delete.
	<info>: New.
	(remote_target::open_1): Make static.  Adjust.
	* rs6000-nat.c (_initialize_rs6000_nat): Use add_inf_child_target.
	* s390-linux-nat.c (_initialize_s390_nat): Use
	add_inf_child_target.
	* sh-nbsd-nat.c (_initialize_shnbsd_nat): Use
	add_inf_child_target.
	* sol-thread.c (thread_db_target_info): New.
	(sol_thread_target) <shortname, longname, doc>: Delete.
	<info>: New.
	* sparc-linux-nat.c (_initialize_sparc_linux_nat): Use
	add_inf_child_target.
	* sparc-nbsd-nat.c (_initialize_sparcnbsd_nat): Use
	add_inf_child_target.
	* sparc64-fbsd-nat.c (_initialize_sparc64fbsd_nat): Use
	add_inf_child_target.
	* sparc64-linux-nat.c (_initialize_sparc64_linux_nat): Use
	add_inf_child_target.
	* sparc64-nbsd-nat.c (_initialize_sparc64nbsd_nat): Use
	add_inf_child_target.
	* sparc64-obsd-nat.c (_initialize_sparc64obsd_nat): Use
	add_inf_child_target.
	* spu-linux-nat.c (_initialize_spu_nat): Use
	add_inf_child_target.
	* spu-multiarch.c (spu_multiarch_target_info): New.
	(spu_multiarch_target) <shortname, longname, doc>: Delete.
	<info>: New.
	* target-delegates.c: Regenerate.
	* target.c: Include <unordered_map>.
	(target_ops_p): Delete.
	(DEF_VEC_P(target_ops_p)): Delete.
	(target_factories): New.
	(test_target_info): New.
	(test_target_ops::info): New.
	(open_target): Adjust to use target_factories.
	(add_target_with_completer): Rename to ...
	(add_target): ... this.  Change prototype.  Register target_info
	and open callback in target_factories.  Register target_info in
	command context instead of target_ops.
	(add_target): Delete old implementation.
	(add_deprecated_target_alias): Change prototype.  Adjust.
	(the_native_target): New.
	(set_native_target, get_native_target): New.
	(find_default_run_target): Use the_native_target.
	(find_attach_target, find_run_target): Simplify.
	(target_ops::open): Delete.
	(dummy_target_info): New.
	(dummy_target::shortname, dummy_target::longname)
	(dummy_target::doc): Delete.
	(dummy_target::info): New.
	(debug_target::shortname, debug_target::longname)
	(debug_target::doc): Delete.
	(debug_target::info): New.
	* target.h (struct target_info): New.
	(target_ops::~target_ops): Add comment.
	(target_ops::info): New.
	(target_ops::shortname, target_ops::longname, target_ops::doc): No
	longer virtual.  Implement in terms of target_info.
	(set_native_target, get_native_target): Declare.
	(target_open_ftype): New.
	(add_target, add_target_with_completer)
	(add_deprecated_target_alias): Change prototype.
	(test_target) <shortname, longname, doc>: Delete.
	<info>: New.
	* tilegx-linux-nat.c (_initialize_tile_linux_nat): Use
	add_inf_child_target.
	* tracefile-tfile.c (tfile_target_info): New.
	(tfile_target) <shortname, longname, doc>: Delete.
	<info>: New.
	(tfile_target::open): Rename to ...
	(tfile_target_open): ... this.
	(_initialize_tracefile_tfile): Adjust.
	* vax-bsd-nat.c (_initialize_vaxbsd_nat): Use
	add_inf_child_target.
	* windows-nat.c (_initialize_windows_nat): Use
	add_inf_child_target.
	* xtensa-linux-nat.c (_initialize_xtensa_linux_nat): Use
	add_inf_child_target.
2018-05-03 00:53:12 +01:00

129 lines
4.3 KiB
C++

/* Base/prototype target for default child (native) targets.
Copyright (C) 2004-2018 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 INF_CHILD_H
#define INF_CHILD_H
#include "target.h"
/* A prototype child target. The client can override it with local
methods. */
class inf_child_target
: public memory_breakpoint_target<target_ops>
{
public:
inf_child_target ();
~inf_child_target () override = 0;
const target_info &info () const override;
void close () override;
void disconnect (const char *, int) override;
void fetch_registers (struct regcache *, int) override = 0;
void store_registers (struct regcache *, int) override = 0;
void prepare_to_store (struct regcache *) override;
bool supports_terminal_ours () override;
void terminal_init () override;
void terminal_inferior () override;
void terminal_ours_for_output () override;
void terminal_ours () override;
void terminal_info (const char *, int) override;
void interrupt () override;
void pass_ctrlc () override;
void post_startup_inferior (ptid_t) override;
void mourn_inferior () override;
bool can_run () override;
bool can_create_inferior () override;
void create_inferior (const char *, const std::string &,
char **, int) override = 0;
bool can_attach () override;
void attach (const char *, int) override = 0;
void post_attach (int) override;
/* We must default these because they must be implemented by any
target that can run. */
bool can_async_p () override { return false; }
bool supports_non_stop () override { return false; }
bool supports_disable_randomization () override { return false; }
char *pid_to_exec_file (int pid) override;
bool has_all_memory () override;
bool has_memory () override;
bool has_stack () override;
bool has_registers () override;
bool has_execution (ptid_t) override;
int fileio_open (struct inferior *inf, const char *filename,
int flags, int mode, int warn_if_slow,
int *target_errno) override;
int fileio_pwrite (int fd, const gdb_byte *write_buf, int len,
ULONGEST offset, int *target_errno) override;
int fileio_pread (int fd, gdb_byte *read_buf, int len,
ULONGEST offset, int *target_errno) override;
int fileio_fstat (int fd, struct stat *sb, int *target_errno) override;
int fileio_close (int fd, int *target_errno) override;
int fileio_unlink (struct inferior *inf,
const char *filename,
int *target_errno) override;
gdb::optional<std::string> fileio_readlink (struct inferior *inf,
const char *filename,
int *target_errno) override;
bool use_agent (bool use) override;
bool can_use_agent () override;
protected:
/* Unpush the target if it wasn't explicitly open with "target native"
and there are no live inferiors left. Note: if calling this as a
result of a mourn or detach, the current inferior shall already
have its PID cleared, so it isn't counted as live. That's usually
done by calling either generic_mourn_inferior or
detach_inferior. */
void maybe_unpush_target ();
};
/* Functions for helping to write a native target. */
/* This is for native targets which use a unix/POSIX-style waitstatus. */
extern void store_waitstatus (struct target_waitstatus *, int);
/* Register TARGET as native target and set it up to respond to the
"target native" command. */
extern void add_inf_child_target (inf_child_target *target);
/* target_open_ftype callback for inf-child targets. Used by targets
that want to register an alternative target_info object. Most
targets use add_inf_child_target instead. */
extern void inf_child_open_target (const char *arg, int from_tty);
#endif