2009-10-19 Pedro Alves <pedro@codesourcery.com>

	    Stan Shebs	<stan@codesourcery.com>

	Add base multi-executable/process support to GDB.

	gdb/
	* Makefile.in (SFILES): Add progspace.c.
	(COMMON_OBS): Add progspace.o.
	* progspace.h: New.
	* progspace.c: New.

	* breakpoint.h (struct bp_target_info) <placed_address_space>: New
	field.
	(struct bp_location) <pspace>: New field.
	(struct breakpoint) <pspace>: New field.
	(bpstat_stop_status, breakpoint_here_p)
	(moribund_breakpoint_here_p, breakpoint_inserted_here_p)
	(regular_breakpoint_inserted_here_p)
	(software_breakpoint_inserted_here_p, breakpoint_thread_match)
	(set_default_breakpoint): Adjust prototypes.
	(remove_breakpoints_pid, breakpoint_program_space_exit): Declare.
	(insert_single_step_breakpoint, deprecated_insert_raw_breakpoint):
	Adjust prototypes.
	* breakpoint.c (executing_startup): Delete.
	(default_breakpoint_sspace): New.
	(breakpoint_restore_shadows): Skip if the address space doesn't
	match.
	(update_watchpoint): Record the frame's program space in the
	breakpoint location.
	(insert_bp_location): Record the address space in target_info.
	Adjust to pass the symbol space to solib_name_from_address.
	(breakpoint_program_space_exit): New.
	(insert_breakpoint_locations): Switch the symbol space and thread
	when inserting breakpoints.  Don't insert breakpoints in a vfork
	parent waiting for vfork done if we're not attached to the vfork
	child.
	(remove_breakpoints_pid): New.
	(reattach_breakpoints): Switch to a thread of PID.  Ignore
	breakpoints of other symbol spaces.
	(create_internal_breakpoint): Store the symbol space in the sal.
	(create_longjmp_master_breakpoint): Iterate over all symbol
	spaces.
	(update_breakpoints_after_exec): Ignore breakpoints for other
	symbol spaces.
	(remove_breakpoint): Rename to ...
	(remove_breakpoint_1): ... this.  Pass the breakpoints symbol
	space to solib_name_from_address.
	(remove_breakpoint): New.
	(mark_breakpoints_out): Ignore breakpoints from other symbol
	spaces.
	(breakpoint_init_inferior): Ditto.
	(breakpoint_here_p): Add an address space argument and adjust to
	use breakpoint_address_match.
	(moribund_breakpoint_here_p): Ditto.
	(regular_breakpoint_inserted_here_p): Ditto.
	(breakpoint_inserted_here_p): Ditto.
	(software_breakpoint_inserted_here_p): Ditto.
	(breakpoint_thread_match): Ditto.
	(bpstat_check_location): Ditto.
	(bpstat_stop_status): Ditto.
	(print_breakpoint_location): If there's a location to print,
	switch the current symbol space.
	(print_one_breakpoint_location): Add `allflag' argument.
	(print_one_breakpoint): Ditto.	Adjust.
	(do_captured_breakpoint_query): Adjust.
	(breakpoint_1): Adjust.
	(breakpoint_has_pc): Also match the symbol space.
	(describe_other_breakpoints): Add a symbol space argument and
	adjust.
	(set_default_breakpoint): Add a symbol space argument.	Set
	default_breakpoint_sspace.
	(breakpoint_address_match): New.
	(check_duplicates_for): Add an address space argument, and adjust.
	(set_raw_breakpoint): Record the symbol space in the location and
	in the breakpoint.
	(set_longjmp_breakpoint): Skip longjmp master breakpoints from
	other symbol spaces.
	(remove_thread_event_breakpoints, remove_solib_event_breakpoints)
	(disable_breakpoints_in_shlibs): Skip breakpoints from other
	symbol spaces.
	(disable_breakpoints_in_unloaded_shlib): Match symbol spaces.
	(create_catchpoint): Set the symbol space in the sal.
	(disable_breakpoints_before_startup): Skip breakpoints from other
	symbol spaces.	Set executing_startup in the current symbol space.
	(enable_breakpoints_after_startup): Clear executing_startup in the
	current symbol space.  Skip breakpoints from other symbol spaces.
	(clone_momentary_breakpoint): Also copy the symbol space.
	(add_location_to_breakpoint): Set the location's symbol space.
	(bp_loc_is_permanent): Switch thread and symbol space.
	(create_breakpoint): Adjust.
	(expand_line_sal_maybe): Expand comment to mention symbol spaces.
	Switch thread and symbol space when reading memory.
	(parse_breakpoint_sals): Set the symbol space in the sal.
	(break_command_really): Ditto.
	(skip_prologue_sal): Switch and space.
	(resolve_sal_pc): Ditto.
	(watch_command_1): Record the symbol space in the sal.
	(create_ada_exception_breakpoint): Adjust.
	(clear_command): Adjust.  Match symbol spaces.
	(update_global_location_list): Use breakpoint_address_match.
	(breakpoint_re_set_one): Switch thread and space.
	(breakpoint_re_set): Save symbol space.
	(breakpoint_re_set_thread): Also reset the symbol space.
	(deprecated_insert_raw_breakpoint): Add an address space argument.
	Adjust.
	(insert_single_step_breakpoint): Ditto.
	(single_step_breakpoint_inserted_here_p): Ditto.
	(clear_syscall_counts): New.
	(_initialize_breakpoint): Install it as inferior_exit observer.

	* exec.h: Include "progspace.h".
	(exec_bfd, exec_bfd_mtime): New defines.
	(exec_close): Declare.
	* exec.c: Include "gdbthread.h" and "progspace.h".
	(exec_bfd, exec_bfd_mtime, current_target_sections_1): Delete.
	(using_exec_ops): New.
	(exec_close_1): Rename to exec_close, and make public.
	(exec_close): Rename to exec_close_1, and adjust all callers.  Add
	description.  Remove target sections and close executables from
	all program spaces.
	(exec_file_attach): Add comment.
	(add_target_sections): Check on `using_exec_ops' to check if the
	target should be pushed.
	(remove_target_sections): Only unpush the target if there are no
	more target sections in any symbol space.
	* gdbcore.h: Include "exec.h".
	(exec_bfd, exec_bfd_mtime): Remove declarations.

	* frame.h (get_frame_program_space, get_frame_address_space)
	(frame_unwind_program_space): Declare.
	* frame.c (struct frame_info) <pspace, aspace>: New fields.
	(create_sentinel_frame): Add program space argument.  Set the
	pspace and aspace fields of the frame object.
	(get_current_frame, create_new_frame): Adjust.
	(get_frame_program_space): New.
	(frame_unwind_program_space): New.
	(get_frame_address_space): New.
	* stack.c (print_frame_info): Adjust.
	(print_frame): Use the frame's program space.

	* gdbthread.h (any_live_thread_of_process): Declare.
	* thread.c (any_live_thread_of_process): New.
	(switch_to_thread): Switch the program space as well.
	(restore_selected_frame): Don't warn if trying to restore frame
	level 0.

	* inferior.h: Include "progspace.h".
	(detach_fork): Declare.
	(struct inferior) <removable, aspace, pspace>
	<vfork_parent, vfork_child, pending_detach>
	<waiting_for_vfork_done>: New fields.
	<terminal_info>: Remove field.
	<data, num_data>: New fields.
	(register_inferior_data, register_inferior_data_with_cleanup)
	(clear_inferior_data, set_inferior_data, inferior_data): Declare.
	(exit_inferior, exit_inferior_silent, exit_inferior_num_silent)
	(inferior_appeared): Declare.
	(find_inferior_pid): Typo.
	(find_inferior_id, find_inferior_for_program_space): Declare.
	(set_current_inferior, save_current_inferior, prune_inferiors)
	(number_of_inferiors): Declare.
	(inferior_list): Declare.
	* inferior.c: Include "gdbcore.h" and "symfile.h".
	(inferior_list): Make public.
	(delete_inferior_1): Always delete thread silently.
	(find_inferior_id): Make public.
	(current_inferior_): New.
	(current_inferior): Use it.
	(set_current_inferior): New.
	(restore_inferior): New.
	(save_current_inferior): New.
	(free_inferior): Free the per-inferior data.
	(add_inferior_silent): Allocate per-inferior data.
	Call inferior_appeared.
	(delete_threads_of_inferior): New.
	(delete_inferior_1): Adjust interface to take an inferior pointer.
	(delete_inferior): Adjust.
	(delete_inferior_silent): Adjust.
	(exit_inferior_1): New.
	(exit_inferior): New.
	(exit_inferior_silent): New.
	(exit_inferior_num_silent): New.
	(detach_inferior): Adjust.
	(inferior_appeared): New.
	(discard_all_inferiors): Adjust.
	(find_inferior_id): Make public.  Assert pid is not zero.
	(find_inferior_for_program_space): New.
	(have_inferiors): Check if we have any inferior with pid not zero.
	(have_live_inferiors): Go over all pushed targets looking for
	process_stratum.
	(prune_inferiors): New.
	(number_of_inferiors): New.
	(print_inferior): Add executable column.  Print vfork parent/child
	relationships.
	(inferior_command): Adjust to cope with not running inferiors.
	(remove_inferior_command): New.
	(add_inferior_command): New.
	(clone_inferior_command): New.
	(struct inferior_data): New.
	(struct inferior_data_registration): New.
	(struct inferior_data_registry): New.
	(inferior_data_registry): New.
	(register_inferior_data_with_cleanup): New.
	(register_inferior_data): New.
	(inferior_alloc_data): New.
	(inferior_free_data): New.
	(clear_inferior_data): New.
	(set_inferior_data): New.
	(inferior_data): New.
	(initialize_inferiors): New.
	(_initialize_inferiors): Register "add-inferior",
	"remove-inferior" and "clone-inferior" commands.

	* objfiles.h: Include "progspace.h".
	(struct objfile) <pspace>: New field.
	(symfile_objfile, object_files): Don't declare.
	(ALL_PSPACE_OBJFILES): New.
	(ALL_PSPACE_OBJFILES_SAFE): New.
	(ALL_OBJFILES, ALL_OBJFILES_SAFE): Adjust.
	(ALL_PSPACE_SYMTABS): New.
	(ALL_PRIMARY_SYMTABS): Adjust.
	(ALL_PSPACE_PRIMARY_SYMTABS): New.
	(ALL_PSYMTABS): Adjust.
	(ALL_PSPACE_PSYMTABS): New.
	* objfiles.c (object_files, symfile_objfile): Delete.
	(struct objfile_sspace_info): New.
	(objfiles_pspace_data): New.
	(objfiles_pspace_data_cleanup): New.
	(get_objfile_pspace_data): New.
	(objfiles_changed_p): Delete.
	(allocate_objfile): Set the objfile's program space.  Adjust to
	reference objfiles_changed_p in pspace data.
	(free_objfile): Adjust to reference objfiles_changed_p in pspace
	data.
	(objfile_relocate): Ditto.
	(update_section_map): Add pspace argument.  Adjust to iterate over
	objfiles in the passed in pspace.
	(find_pc_section): Delete sections and num_sections statics.
	Adjust to refer to program space's objfiles_changed_p.	Adjust to
	refer to sections and num_sections store in the objfile's pspace
	data.
	(objfiles_changed): Adjust to reference objfiles_changed_p in
	pspace data.
	(_initialize_objfiles): New.
	* linespec.c (decode_all_digits, decode_dollar): Set the sal's
	program space.
	* source.c (current_source_pspace): New.
	(get_current_source_symtab_and_line): Set the sal's program space.
	(set_current_source_symtab_and_line): Set current_source_pspace.
	(select_source_symtab): Ditto.	Use ALL_OBJFILES.
	(forget_cached_source_info): Iterate over all program spaces.
	* symfile.c (clear_symtab_users): Adjust.
	* symmisc.c (print_symbol_bcache_statistics): Iterate over all
	program spaces.
	(print_objfile_statistics): Ditto.
	(maintenance_print_msymbols): Ditto.
	(maintenance_print_objfiles): Ditto.
	(maintenance_info_symtabs): Ditto.
	(maintenance_info_psymtabs): Ditto.
	* symtab.h (SYMTAB_PSPACE): New.
	(struct symtab_and_line) <pspace>: New field.
	* symtab.c (init_sal): Clear the sal's program space.
	(find_pc_sect_symtab): Set the sal's program space.  Switch thread
	and space.
	(append_expanded_sal): Add program space argument.  Iterate over
	all program spaces.
	(expand_line_sal): Iterate over all program spaces.  Switch
	program space.

	* target.h (enum target_waitkind) <TARGET_WAITKIND_VFORK_DONE>: New.
	(struct target_ops) <to_thread_address_space>: New field.
	(target_thread_address_space): Define.
	* target.c (target_detach): Only remove breakpoints from the
	inferior we're detaching.
	(target_thread_address_space): New.

	* defs.h (initialize_progspace): Declare.
	* top.c (gdb_init): Call it.

	* solist.h (struct so_list) <sspace>: New field.
	* solib.h (struct program_space): Forward declare.
	(solib_name_from_address): Adjust prototype.
	* solib.c (so_list_head): Replace with a macro referencing the
	program space.
	(update_solib_list): Set the so's program space.
	(solib_name_from_address): Add a program space argument and adjust.

	* solib-svr4.c (struct svr4_info) <pid>: Delete field.
	<interp_text_sect_low, interp_text_sect_high, interp_plt_sect_low>
	<interp_plt_sect_high>: New fields.
	(svr4_info_p, svr4_info): Delete.
	(solib_svr4_sspace_data): New.
	(get_svr4_info): Rewrite.
	(svr4_sspace_data_cleanup): New.
	(open_symbol_file_object): Adjust.
	(svr4_default_sos): Adjust.
	(svr4_fetch_objfile_link_map): Adjust.
	(interp_text_sect_low, interp_text_sect_high, interp_plt_sect_low)
	(interp_plt_sect_high): Delete.
	(svr4_in_dynsym_resolve_code): Adjust.
	(enable_break): Adjust.
	(svr4_clear_solib): Revert bit that removed the svr4_info here,
	and reinstate clearing debug_base, debug_loader_offset_p,
	debug_loader_offset and debug_loader_name.
	(_initialize_svr4_solib): Register solib_svr4_pspace_data.  Don't
	install an inferior_exit observer anymore.

	* printcmd.c (struct display) <pspace>: New field.
	(display_command): Set the display's sspace.
	(do_one_display): Match the display's sspace.
	(display_uses_solib_p): Ditto.

	* linux-fork.c (detach_fork): Moved to infrun.c.
	(_initialize_linux_fork): Moved "detach-on-fork" command to
	infrun.c.
	* infrun.c (detach_fork): Moved from linux-fork.c.
	(proceed_after_vfork_done): New.
	(handle_vfork_child_exec_or_exit): New.
	(follow_exec_mode_replace, follow_exec_mode_keep)
	(follow_exec_mode_names, follow_exec_mode_string)
	(show_follow_exec_mode_string): New.
	(follow_exec): New.  Reinstate the mark_breakpoints_out call.
	Remove shared libraries before attaching new executable.  If user
	wants to keep the inferior, keep it.
	(displaced_step_fixup): Adjust to pass an address space to the
	breakpoints module.
	(resume): Ditto.
	(clear_proceed_status): In all-stop mode, always clear the proceed
	status of all threads.
	(prepare_to_proceed): Adjust to pass an address space to the
	breakpoints module.
	(proceed): Ditto.
	(adjust_pc_after_break): Ditto.
	(handle_inferior_event): When handling a process exit, switch the
	program space to the inferior's that had exited.  Call
	handle_vfork_child_exec_or_exit.  Adjust to pass an address space
	to the breakpoints module.  In non-stop mode, when following a
	fork and detach-fork is off, also resume the other branch.  Handle
	TARGET_WAITKIND_VFORK_DONE.  Set the program space in sals.
	(normal_stop): Prune inferiors.
	(_initialize_infrun): Install the new "follow-exec-mode" command.
	"detach-on-fork" moved here.

	* regcache.h (get_regcache_aspace): Declare.
	* regcache.c (struct regcache) <aspace>: New field.
	(regcache_xmalloc): Clear the aspace.
	(get_regcache_aspace): New.
	(regcache_cpy): Copy the aspace field.
	(regcache_cpy_no_passthrough): Ditto.
	(get_thread_regcache): Fetch the thread's address space from the
	target, and store it in the regcache.

	* infcall.c (call_function_by_hand): Set the sal's pspace.

	* arch-utils.c (default_has_shared_address_space): New.
	* arch-utils.h (default_has_shared_address_space): Declare.

	* gdbarch.sh (has_shared_address_space): New.
	* gdbarch.h, gdbarch.c: Regenerate.

	* linux-tdep.c: Include auxv.h, target.h, elf/common.h.
	(linux_has_shared_address_space): New.
	(_initialize_linux_tdep): Declare.

	* arm-tdep.c (arm_software_single_step): Pass the frame's address
	space to insert_single_step_breakpoint.
	* arm-linux-tdep.c (arm_linux_software_single_step): Pass the
	frame's pspace to breakpoint functions.
	* cris-tdep.c (crisv32_single_step_through_delay): Ditto.
	(cris_software_single_step): Ditto.
	* mips-tdep.c (deal_with_atomic_sequence): Add frame argument.
	Pass the frame's pspace to breakpoint functions.
	(mips_software_single_step): Adjust.
	(mips_single_step_through_delay): Adjust.
	* rs6000-aix-tdep.c (rs6000_software_single_step): Adjust.
	* rs6000-tdep.c (ppc_deal_with_atomic_sequence): Adjust.
	* solib-irix.c (enable_break): Adjust to pass the current frame's
	address space to breakpoint functions.
	* sparc-tdep.c (sparc_software_single_step): Ditto.
	* spu-tdep.c (spu_software_single_step): Ditto.
	* alpha-tdep.c (alpha_software_single_step): Ditto.
	* record.c (record_wait): Adjust to pass an address space to the
	breakpoints module.

	* fork-child.c (fork_inferior): Set the new inferior's program and
	address spaces.
	* inf-ptrace.c (inf_ptrace_follow_fork): Copy the parent's program
	and address spaces.
	(inf_ptrace_attach): Set the inferior's program and address spaces.
	* linux-nat.c: Include "solib.h".
	(linux_child_follow_fork): Manage parent and child's program and
	address spaces.	 Clone the parent's program space if necessary.
	Don't wait for the vfork to be done here.  Refuse to resume if
	following the vfork parent while leaving the child stopped.
	(resume_callback): Don't resume a vfork parent.
	(linux_nat_resume): Also check for pending events in the
	lp->waitstatus field.
	(linux_handle_extended_wait): Report TARGET_WAITKIND_VFORK_DONE
	events to the core.
	(stop_wait_callback): Don't wait for SIGSTOP on vfork parents.
	(cancel_breakpoint): Adjust.
	* linux-thread-db.c (thread_db_wait): Don't remove thread event
	breakpoints here.
	(thread_db_mourn_inferior): Don't mark breakpoints out here.
	Remove thread event breakpoints after mourning.
	* corelow.c: Include progspace.h.
	(core_open): Set the inferior's program and address spaces.
	* remote.c (remote_add_inferior): Set the new inferior's program
	and address spaces.
	(remote_start_remote): Update address spaces.
	(extended_remote_create_inferior_1): Don't init the thread list if
	we already debugging other inferiors.
	* darwin-nat.c (darwin_attach): Set the new inferior's program and
	address spaces.
	* gnu-nat.c (gnu_attach): Ditto.
	* go32-nat.c (go32_create_inferior): Ditto.
	* inf-ttrace.c (inf_ttrace_follow_fork, inf_ttrace_attach): Ditto.
	* monitor.c (monitor_open): Ditto.
	* nto-procfs.c (procfs_attach, procfs_create_inferior): Ditto.
	* procfs.c (do_attach): Ditto.
	* windows-nat.c (do_initial_windows_stuff): Ditto.

	* inflow.c (inferior_process_group)
	(terminal_init_inferior_with_pgrp, terminal_inferior,
	(terminal_ours_1, inflow_inferior_exit, copy_terminal_info)
	(child_terminal_info, new_tty_postfork, set_sigint_trap): Adjust
	to use per-inferior data instead of inferior->terminal_info.
	(inflow_inferior_data): New.
	(inflow_new_inferior): Delete.
	(inflow_inferior_data_cleanup): New.
	(get_inflow_inferior_data): New.

	* mi/mi-interp.c (mi_new_inferior): Rename to...
	(mi_inferior_appeared): ... this.
	(mi_interpreter_init): Adjust.

	* tui/tui-disasm.c: Include "progspace.h".
	(tui_set_disassem_content): Pass an address space to
	breakpoint_here_p.

	* NEWS: Mention multi-program debugging support.  Mention new
	commands "add-inferior", "clone-inferior", "remove-inferior",
	"maint info program-spaces", and new option "set
	follow-exec-mode".

2009-10-19  Pedro Alves	 <pedro@codesourcery.com>
	    Stan Shebs	<stan@codesourcery.com>

	gdb/doc/
	* observer.texi (new_inferior): Rename to...
	(inferior_appeared): ... this.

2009-10-19  Pedro Alves	 <pedro@codesourcery.com>
	    Stan Shebs	<stan@codesourcery.com>

	gdb/testsuite/
	* gdb.base/foll-vfork.exp: Adjust to spell out "follow-fork".
	* gdb.base/foll-exec.exp: Adjust to expect a process id before
	"Executing new program".
	* gdb.base/foll-fork.exp: Adjust to spell out "follow-fork".
	* gdb.base/multi-forks.exp: Ditto.  Adjust to the inferior being
	left listed after having been killed.
	* gdb.base/attach.exp: Adjust to spell out "symbol-file".
	* gdb.base/maint.exp: Adjust test.

	* Makefile.in (ALL_SUBDIRS): Add gdb.multi.
	* gdb.multi/Makefile.in: New.
	* gdb.multi/base.exp: New.
	* gdb.multi/goodbye.c: New.
	* gdb.multi/hangout.c: New.
	* gdb.multi/hello.c: New.
	* gdb.multi/bkpt-multi-exec.c: New.
	* gdb.multi/bkpt-multi-exec.exp: New.
	* gdb.multi/crashme.c: New.

2009-10-19  Pedro Alves	 <pedro@codesourcery.com>
	    Stan Shebs	<stan@codesourcery.com>

	gdb/doc/
	* gdb.texinfo (Inferiors): Rename node to ...
	(Inferiors and Programs): ... this.  Mention running multiple
	programs in the same debug session.
	<info inferiors>: Mention the new 'Executable' column if "info
	inferiors".  Update examples.  Document the "add-inferior",
	"clone-inferior", "remove-inferior" and "maint info
	program-spaces" commands.
	(Process): Rename node to...
	(Forks): ... this.  Document "set|show follow-exec-mode".

1 files changed, 611 insertions, 58 deletions

diff --git a/gdb/inferior.c b/gdb/inferior.c
index 676fff9..87d9a45 100644
--- a/gdb/inferior.c
+++ b/gdb/inferior.c
@@ -18,6 +18,7 @@
    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
 
 #include "defs.h"
+#include "exec.h"
 #include "inferior.h"
 #include "target.h"
 #include "command.h"
@@ -26,28 +27,66 @@
 #include "ui-out.h"
 #include "observer.h"
 #include "gdbthread.h"
+#include "gdbcore.h"
+#include "symfile.h"
 
 void _initialize_inferiors (void);
 
-static struct inferior *inferior_list = NULL;
+static void inferior_alloc_data (struct inferior *inf);
+static void inferior_free_data (struct inferior *inf);
+
+struct inferior *inferior_list = NULL;
 static int highest_inferior_num;
 
 /* Print notices on inferior events (attach, detach, etc.), set with
    `set print inferior-events'.  */
 static int print_inferior_events = 0;
 
+/* The Current Inferior.  */
+static struct inferior *current_inferior_ = NULL;
+
 struct inferior*
 current_inferior (void)
 {
-  struct inferior *inf = find_inferior_pid (ptid_get_pid (inferior_ptid));
-  gdb_assert (inf);
-  return inf;
+  return current_inferior_;
+}
+
+void
+set_current_inferior (struct inferior *inf)
+{
+  /* There's always an inferior.  */
+  gdb_assert (inf != NULL);
+
+  current_inferior_ = inf;
+}
+
+/* A cleanups callback, helper for save_current_program_space
+   below.  */
+
+static void
+restore_inferior (void *arg)
+{
+  struct inferior *saved_inferior = arg;
+  set_current_inferior (saved_inferior);
+}
+
+/* Save the current program space so that it may be restored by a later
+   call to do_cleanups.  Returns the struct cleanup pointer needed for
+   later doing the cleanup.  */
+
+struct cleanup *
+save_current_inferior (void)
+{
+  struct cleanup *old_chain = make_cleanup (restore_inferior,
+					    current_inferior_);
+  return old_chain;
 }
 
 static void
 free_inferior (struct inferior *inf)
 {
   discard_all_inferior_continuations (inf);
+  inferior_free_data (inf);
   xfree (inf->private);
   xfree (inf);
 }
@@ -85,7 +124,10 @@ add_inferior_silent (int pid)
   inf->next = inferior_list;
   inferior_list = inf;
 
-  observer_notify_new_inferior (pid);
+  inferior_alloc_data (inf);
+
+  if (pid != 0)
+    inferior_appeared (inf, pid);
 
   return inf;
 }
@@ -123,32 +165,48 @@ delete_thread_of_inferior (struct thread_info *tp, void *data)
   return 0;
 }
 
+void
+delete_threads_of_inferior (int pid)
+{
+  struct inferior *inf;
+  struct delete_thread_of_inferior_arg arg;
+
+  for (inf = inferior_list; inf; inf = inf->next)
+    if (inf->pid == pid)
+      break;
+
+  if (!inf)
+    return;
+
+  arg.pid = pid;
+  arg.silent = 1;
+
+  iterate_over_threads (delete_thread_of_inferior, &arg);
+}
+
 /* If SILENT then be quiet -- don't announce a inferior death, or the
    exit of its threads.  */
+
 static void
-delete_inferior_1 (int pid, int silent)
+delete_inferior_1 (struct inferior *todel, int silent)
 {
   struct inferior *inf, *infprev;
-  struct delete_thread_of_inferior_arg arg = { pid, silent };
+  struct delete_thread_of_inferior_arg arg;
 
   infprev = NULL;
 
   for (inf = inferior_list; inf; infprev = inf, inf = inf->next)
-    if (inf->pid == pid)
+    if (inf == todel)
       break;
 
   if (!inf)
     return;
 
-  arg.pid = pid;
+  arg.pid = inf->pid;
   arg.silent = silent;
 
   iterate_over_threads (delete_thread_of_inferior, &arg);
 
-  /* Notify the observers before removing the inferior from the list,
-     so that the observers have a change to look it up.  */
-  observer_notify_inferior_exit (pid);
-
   if (infprev)
     infprev->next = inf->next;
   else
@@ -160,7 +218,9 @@ delete_inferior_1 (int pid, int silent)
 void
 delete_inferior (int pid)
 {
-  delete_inferior_1 (pid, 0);
+  struct inferior *inf = find_inferior_pid (pid);
+
+  delete_inferior_1 (inf, 0);
 
   if (print_inferior_events)
     printf_unfiltered (_("[Inferior %d exited]\n"), pid);
@@ -169,31 +229,101 @@ delete_inferior (int pid)
 void
 delete_inferior_silent (int pid)
 {
-  delete_inferior_1 (pid, 1);
+  struct inferior *inf = find_inferior_pid (pid);
+
+  delete_inferior_1 (inf, 1);
+}
+
+
+/* If SILENT then be quiet -- don't announce a inferior exit, or the
+   exit of its threads.  */
+
+static void
+exit_inferior_1 (struct inferior *inftoex, int silent)
+{
+  struct inferior *inf;
+  struct delete_thread_of_inferior_arg arg;
+
+  for (inf = inferior_list; inf; inf = inf->next)
+    if (inf == inftoex)
+      break;
+
+  if (!inf)
+    return;
+
+  arg.pid = inf->pid;
+  arg.silent = silent;
+
+  iterate_over_threads (delete_thread_of_inferior, &arg);
+
+  /* Notify the observers before removing the inferior from the list,
+     so that the observers have a chance to look it up.  */
+  observer_notify_inferior_exit (inf->pid);
+
+  inf->pid = 0;
+  if (inf->vfork_parent != NULL)
+    {
+      inf->vfork_parent->vfork_child = NULL;
+      inf->vfork_parent = NULL;
+    }
+}
+
+void
+exit_inferior (int pid)
+{
+  struct inferior *inf = find_inferior_pid (pid);
+  exit_inferior_1 (inf, 0);
+
+  if (print_inferior_events)
+    printf_unfiltered (_("[Inferior %d exited]\n"), pid);
+}
+
+void
+exit_inferior_silent (int pid)
+{
+  struct inferior *inf = find_inferior_pid (pid);
+  exit_inferior_1 (inf, 1);
+}
+
+void
+exit_inferior_num_silent (int num)
+{
+  struct inferior *inf = find_inferior_id (num);
+
+  exit_inferior_1 (inf, 1);
 }
 
 void
 detach_inferior (int pid)
 {
-  delete_inferior_1 (pid, 1);
+  struct inferior *inf = find_inferior_pid (pid);
+  exit_inferior_1 (inf, 1);
 
   if (print_inferior_events)
     printf_unfiltered (_("[Inferior %d detached]\n"), pid);
 }
 
 void
+inferior_appeared (struct inferior *inf, int pid)
+{
+  inf->pid = pid;
+
+  observer_notify_inferior_appeared (pid);
+}
+
+void
 discard_all_inferiors (void)
 {
-  struct inferior *inf, *infnext;
+  struct inferior *inf;
 
-  for (inf = inferior_list; inf; inf = infnext)
+  for (inf = inferior_list; inf; inf = inf->next)
     {
-      infnext = inf->next;
-      delete_inferior_silent (inf->pid);
+      if (inf->pid != 0)
+	exit_inferior_silent (inf->pid);
     }
 }
 
-static struct inferior *
+struct inferior *
 find_inferior_id (int num)
 {
   struct inferior *inf;
@@ -210,6 +340,11 @@ find_inferior_pid (int pid)
 {
   struct inferior *inf;
 
+  /* Looking for inferior pid == 0 is always wrong, and indicative of
+     a bug somewhere else.  There may be more than one with pid == 0,
+     for instance.  */
+  gdb_assert (pid != 0);
+
   for (inf = inferior_list; inf; inf = inf->next)
     if (inf->pid == pid)
       return inf;
@@ -217,6 +352,22 @@ find_inferior_pid (int pid)
   return NULL;
 }
 
+/* Find an inferior bound to PSPACE.  */
+
+struct inferior *
+find_inferior_for_program_space (struct program_space *pspace)
+{
+  struct inferior *inf;
+
+  for (inf = inferior_list; inf != NULL; inf = inf->next)
+    {
+      if (inf->pspace == pspace)
+	return inf;
+    }
+
+  return NULL;
+}
+
 struct inferior *
 iterate_over_inferiors (int (*callback) (struct inferior *, void *),
 			void *data)
@@ -282,15 +433,72 @@ in_inferior_list (int pid)
 int
 have_inferiors (void)
 {
-  return inferior_list != NULL;
+  struct inferior *inf;
+
+  for (inf = inferior_list; inf; inf = inf->next)
+    if (inf->pid != 0)
+      return 1;
+
+  return 0;
 }
 
 int
 have_live_inferiors (void)
 {
+  struct target_ops *t;
+
   /* The check on stratum suffices, as GDB doesn't currently support
      multiple target interfaces.  */
-  return (current_target.to_stratum >= process_stratum && have_inferiors ());
+  if (have_inferiors ())
+    for (t = current_target.beneath; t != NULL; t = t->beneath)
+      if (t->to_stratum == process_stratum)
+	return 1;
+
+  return 0;
+}
+
+/* Prune away automatically added program spaces that aren't required
+   anymore.  */
+
+void
+prune_inferiors (void)
+{
+  struct inferior *ss, **ss_link;
+  struct inferior *current = current_inferior ();
+
+  ss = inferior_list;
+  ss_link = &inferior_list;
+  while (ss)
+    {
+      if (ss == current
+	  || !ss->removable
+	  || ss->pid != 0)
+	{
+	  ss_link = &ss->next;
+	  ss = *ss_link;
+	  continue;
+	}
+
+      *ss_link = ss->next;
+      delete_inferior_1 (ss, 1);
+      ss = *ss_link;
+    }
+
+  prune_program_spaces ();
+}
+
+/* Simply returns the count of inferiors.  */
+
+int
+number_of_inferiors (void)
+{
+  struct inferior *inf;
+  int count = 0;
+
+  for (inf = inferior_list; inf != NULL; inf = inf->next)
+    count++;
+
+  return count;
 }
 
 /* Prints the list of inferiors and their details on UIOUT.  This is a
@@ -322,13 +530,14 @@ print_inferior (struct ui_out *uiout, int requested_inferior)
       return;
     }
 
-  old_chain = make_cleanup_ui_out_table_begin_end (uiout, 3, inf_count,
+  old_chain = make_cleanup_ui_out_table_begin_end (uiout, 4, inf_count,
 						   "inferiors");
   ui_out_table_header (uiout, 1, ui_left, "current", "");
   ui_out_table_header (uiout, 4, ui_left, "number", "Num");
   ui_out_table_header (uiout, 17, ui_left, "target-id", "Description");
-  ui_out_table_body (uiout);
+  ui_out_table_header (uiout, 17, ui_left, "exec", "Executable");
 
+  ui_out_table_body (uiout);
   for (inf = inferior_list; inf; inf = inf->next)
     {
       struct cleanup *chain2;
@@ -338,24 +547,43 @@ print_inferior (struct ui_out *uiout, int requested_inferior)
 
       chain2 = make_cleanup_ui_out_tuple_begin_end (uiout, NULL);
 
-      if (inf->pid == ptid_get_pid (inferior_ptid))
+      if (inf == current_inferior ())
 	ui_out_field_string (uiout, "current", "*");
       else
 	ui_out_field_skip (uiout, "current");
 
       ui_out_field_int (uiout, "number", inf->num);
-      ui_out_field_string (uiout, "target-id",
-			   target_pid_to_str (pid_to_ptid (inf->pid)));
+
+      if (inf->pid)
+	ui_out_field_string (uiout, "target-id",
+			     target_pid_to_str (pid_to_ptid (inf->pid)));
+      else
+	ui_out_field_string (uiout, "target-id", "<null>");
+
+      if (inf->pspace->ebfd)
+	ui_out_field_string (uiout, "exec",
+			     bfd_get_filename (inf->pspace->ebfd));
+      else
+	ui_out_field_skip (uiout, "exec");
+
+      /* Print extra info that isn't really fit to always present in
+	 tabular form.  Currently we print the vfork parent/child
+	 relationships, if any.  */
+      if (inf->vfork_parent)
+	{
+	  ui_out_text (uiout, _("\n\tis vfork child of inferior "));
+	  ui_out_field_int (uiout, "vfork-parent", inf->vfork_parent->num);
+	}
+      if (inf->vfork_child)
+	{
+	  ui_out_text (uiout, _("\n\tis vfork parent of inferior "));
+	  ui_out_field_int (uiout, "vfork-child", inf->vfork_child->num);
+	}
 
       ui_out_text (uiout, "\n");
       do_cleanups (chain2);
     }
 
-  if (inferior_list
-      && ptid_equal (inferior_ptid, null_ptid))
-    ui_out_message (uiout, 0, "\n\
-No selected inferior/thread.  See `help thread' or `help inferior'.\n");
-
   do_cleanups (old_chain);
 }
 
@@ -414,36 +642,52 @@ kill_inferior_command (char *args, int from_tty)
 static void
 inferior_command (char *args, int from_tty)
 {
-  int num, pid;
-
-  if (!have_inferiors ())
-    error (_("No inferiors"));
+  struct inferior *inf;
+  int num;
 
   num = parse_and_eval_long (args);
 
-  if (!valid_gdb_inferior_id (num))
+  inf = find_inferior_id (num);
+  if (inf == NULL)
     error (_("Inferior ID %d not known."), num);
 
-  pid = gdb_inferior_id_to_pid (num);
+  printf_filtered (_("[Switching to inferior %d [%s] (%s)]\n"),
+		   inf->num,
+		   target_pid_to_str (pid_to_ptid (inf->pid)),
+		   (inf->pspace->ebfd
+		    ? bfd_get_filename (inf->pspace->ebfd)
+		    : _("<noexec>")));
 
-  if (pid != ptid_get_pid (inferior_ptid))
+  if (inf->pid != 0)
     {
-      struct thread_info *tp;
+      if (inf->pid != ptid_get_pid (inferior_ptid))
+	{
+	  struct thread_info *tp;
 
-      tp = any_thread_of_process (pid);
-      if (!tp)
-	error (_("Inferior has no threads."));
+	  tp = any_thread_of_process (inf->pid);
+	  if (!tp)
+	    error (_("Inferior has no threads."));
 
-      switch_to_thread (tp->ptid);
+	  switch_to_thread (tp->ptid);
+	}
+
+      printf_filtered (_("[Switching to thread %d (%s)] "),
+		       pid_to_thread_id (inferior_ptid),
+		       target_pid_to_str (inferior_ptid));
     }
+  else
+    {
+      struct inferior *inf;
 
-  printf_filtered (_("[Switching to thread %d (%s)] "),
-		   pid_to_thread_id (inferior_ptid),
-		   target_pid_to_str (inferior_ptid));
+      inf = find_inferior_id (num);
+      set_current_inferior (inf);
+      switch_to_thread (null_ptid);
+      set_current_program_space (inf->pspace);
+    }
 
-  if (is_running (inferior_ptid))
+  if (inf->pid != 0 && is_running (inferior_ptid))
     ui_out_text (uiout, "(running)\n");
-  else
+  else if (inf->pid != 0)
     {
       ui_out_text (uiout, "\n");
       print_stack_frame (get_selected_frame (NULL), 1, SRC_AND_LOC);
@@ -467,6 +711,184 @@ info_inferiors_command (char *args, int from_tty)
   print_inferior (uiout, requested);
 }
 
+/* remove-inferior ID */
+
+void
+remove_inferior_command (char *args, int from_tty)
+{
+  int num;
+  struct inferior *inf;
+
+  num = parse_and_eval_long (args);
+  inf = find_inferior_id (num);
+
+  if (inf == NULL)
+    error (_("Inferior ID %d not known."), num);
+
+  if (inf == current_inferior ())
+    error (_("Can not remove current symbol inferior."));
+
+  delete_inferior_1 (inf, 1);
+}
+
+
+/* add-inferior [-copies N] [-exec FILENAME]  */
+
+void
+add_inferior_command (char *args, int from_tty)
+{
+  int i, copies = 1;
+  char *exec = NULL;
+  char **argv;
+  struct cleanup *old_chain = make_cleanup (null_cleanup, NULL);
+
+  if (args)
+    {
+      argv = gdb_buildargv (args);
+      make_cleanup_freeargv (argv);
+
+      for (; *argv != NULL; argv++)
+	{
+	  if (**argv == '-')
+	    {
+	      if (strcmp (*argv, "-copies") == 0)
+		{
+		  ++argv;
+		  if (!*argv)
+		    error (_("No argument to -copies"));
+		  copies = parse_and_eval_long (*argv);
+		}
+	      else if (strcmp (*argv, "-exec") == 0)
+		{
+		  ++argv;
+		  if (!*argv)
+		    error (_("No argument to -exec"));
+		  exec = *argv;
+		}
+	    }
+	  else
+	    error (_("Invalid argument"));
+	}
+    }
+
+  save_current_space_and_thread ();
+
+  for (i = 0; i < copies; ++i)
+    {
+      struct address_space *aspace;
+      struct program_space *pspace;
+      struct inferior *inf;
+
+      /* If all inferiors share an address space on this system, this
+	 doesn't really return a new address space; otherwise, it
+	 really does.  */
+      aspace = maybe_new_address_space ();
+      pspace = add_program_space (aspace);
+      inf = add_inferior (0);
+      inf->pspace = pspace;
+      inf->aspace = pspace->aspace;
+
+      printf_filtered (_("Added inferior %d\n"), inf->num);
+
+      if (exec != NULL)
+	{
+	  /* Switch over temporarily, while reading executable and
+	     symbols.q  */
+	  set_current_program_space (pspace);
+	  set_current_inferior (inf);
+	  switch_to_thread (null_ptid);
+
+	  exec_file_attach (exec, from_tty);
+	  symbol_file_add_main (exec, from_tty);
+	}
+    }
+
+  do_cleanups (old_chain);
+}
+
+/* clone-inferior [-copies N] [ID] */
+
+void
+clone_inferior_command (char *args, int from_tty)
+{
+  int i, copies = 1;
+  char **argv;
+  struct inferior *orginf = NULL;
+  struct cleanup *old_chain = make_cleanup (null_cleanup, NULL);
+
+  if (args)
+    {
+      argv = gdb_buildargv (args);
+      make_cleanup_freeargv (argv);
+
+      for (; *argv != NULL; argv++)
+	{
+	  if (**argv == '-')
+	    {
+	      if (strcmp (*argv, "-copies") == 0)
+		{
+		  ++argv;
+		  if (!*argv)
+		    error (_("No argument to -copies"));
+		  copies = parse_and_eval_long (*argv);
+
+		  if (copies < 0)
+		    error (_("Invalid copies number"));
+		}
+	    }
+	  else
+	    {
+	      if (orginf == NULL)
+		{
+		  int num;
+
+		  /* The first non-option (-) argument specified the
+		     program space ID.  */
+		  num = parse_and_eval_long (*argv);
+		  orginf = find_inferior_id (num);
+
+		  if (orginf == NULL)
+		    error (_("Inferior ID %d not known."), num);
+		  continue;
+		}
+	      else
+		error (_("Invalid argument"));
+	    }
+	}
+    }
+
+  /* If no inferior id was specified, then the user wants to clone the
+     current inferior.  */
+  if (orginf == NULL)
+    orginf = current_inferior ();
+
+  save_current_space_and_thread ();
+
+  for (i = 0; i < copies; ++i)
+    {
+      struct address_space *aspace;
+      struct program_space *pspace;
+      struct inferior *inf;
+
+      /* If all inferiors share an address space on this system, this
+	 doesn't really return a new address space; otherwise, it
+	 really does.  */
+      aspace = maybe_new_address_space ();
+      pspace = add_program_space (aspace);
+      inf = add_inferior (0);
+      inf->pspace = pspace;
+      inf->aspace = pspace->aspace;
+
+      printf_filtered (_("Added inferior %d.\n"), inf->num);
+
+      set_current_inferior (inf);
+      switch_to_thread (null_ptid);
+      clone_program_space (pspace, orginf->pspace);
+    }
+
+  do_cleanups (old_chain);
+}
+
 /* Print notices when new inferiors are created and die.  */
 static void
 show_print_inferior_events (struct ui_file *file, int from_tty,
@@ -475,19 +897,141 @@ show_print_inferior_events (struct ui_file *file, int from_tty,
   fprintf_filtered (file, _("Printing of inferior events is %s.\n"), value);
 }
 
+
+
+/* Keep a registry of per-inferior data-pointers required by other GDB
+   modules.  */
+
+struct inferior_data
+{
+  unsigned index;
+  void (*cleanup) (struct inferior *, void *);
+};
+
+struct inferior_data_registration
+{
+  struct inferior_data *data;
+  struct inferior_data_registration *next;
+};
+
+struct inferior_data_registry
+{
+  struct inferior_data_registration *registrations;
+  unsigned num_registrations;
+};
+
+static struct inferior_data_registry inferior_data_registry
+  = { NULL, 0 };
+
+const struct inferior_data *
+register_inferior_data_with_cleanup
+  (void (*cleanup) (struct inferior *, void *))
+{
+  struct inferior_data_registration **curr;
+
+  /* Append new registration.  */
+  for (curr = &inferior_data_registry.registrations;
+       *curr != NULL; curr = &(*curr)->next);
+
+  *curr = XMALLOC (struct inferior_data_registration);
+  (*curr)->next = NULL;
+  (*curr)->data = XMALLOC (struct inferior_data);
+  (*curr)->data->index = inferior_data_registry.num_registrations++;
+  (*curr)->data->cleanup = cleanup;
+
+  return (*curr)->data;
+}
+
+const struct inferior_data *
+register_inferior_data (void)
+{
+  return register_inferior_data_with_cleanup (NULL);
+}
+
+static void
+inferior_alloc_data (struct inferior *inf)
+{
+  gdb_assert (inf->data == NULL);
+  inf->num_data = inferior_data_registry.num_registrations;
+  inf->data = XCALLOC (inf->num_data, void *);
+}
+
+static void
+inferior_free_data (struct inferior *inf)
+{
+  gdb_assert (inf->data != NULL);
+  clear_inferior_data (inf);
+  xfree (inf->data);
+  inf->data = NULL;
+}
+
 void
-_initialize_inferiors (void)
+clear_inferior_data (struct inferior *inf)
 {
+  struct inferior_data_registration *registration;
+  int i;
+
+  gdb_assert (inf->data != NULL);
+
+  for (registration = inferior_data_registry.registrations, i = 0;
+       i < inf->num_data;
+       registration = registration->next, i++)
+    if (inf->data[i] != NULL && registration->data->cleanup)
+      registration->data->cleanup (inf, inf->data[i]);
+
+  memset (inf->data, 0, inf->num_data * sizeof (void *));
+}
+
+void
+set_inferior_data (struct inferior *inf,
+		       const struct inferior_data *data,
+		       void *value)
+{
+  gdb_assert (data->index < inf->num_data);
+  inf->data[data->index] = value;
+}
+
+void *
+inferior_data (struct inferior *inf, const struct inferior_data *data)
+{
+  gdb_assert (data->index < inf->num_data);
+  return inf->data[data->index];
+}
+
+void
+initialize_inferiors (void)
+{
+  /* There's always one inferior.  Note that this function isn't an
+     automatic _initialize_foo function, since other _initialize_foo
+     routines may need to install their per-inferior data keys.  We
+     can only allocate an inferior when all those modules have done
+     that.  Do this after initialize_progspace, due to the
+     current_program_space reference.  */
+  current_inferior_ = add_inferior (0);
+  current_inferior_->pspace = current_program_space;
+  current_inferior_->aspace = current_program_space->aspace;
+
   add_info ("inferiors", info_inferiors_command,
 	    _("IDs of currently known inferiors."));
 
-  add_setshow_boolean_cmd ("inferior-events", no_class,
-         &print_inferior_events, _("\
-Set printing of inferior events (e.g., inferior start and exit)."), _("\
-Show printing of inferior events (e.g., inferior start and exit)."), NULL,
-         NULL,
-         show_print_inferior_events,
-         &setprintlist, &showprintlist);
+  add_com ("add-inferior", no_class, add_inferior_command, _("\
+Add a new inferior.\n\
+Usage: add-inferior [-copies <N>] [-exec <FILENAME>]\n\
+N is the optional number of inferior to add, default is 1.\n\
+FILENAME is the file name of the executable to use\n\
+as main program."));
+
+  add_com ("remove-inferior", no_class, remove_inferior_command, _("\
+Remove inferior ID.\n\
+Usage: remove-inferior ID"));
+
+  add_com ("clone-inferior", no_class, clone_inferior_command, _("\
+Clone inferior ID.\n\
+Usage: clone-inferior [-copies <N>] [ID]\n\
+Add N copies of inferior ID.  The new inferior has the same\n\
+executable loaded as the copied inferior.  If -copies is not specified,\n\
+adds 1 copy.  If ID is not specified, it is the current inferior\n\
+that is cloned."));
 
   add_cmd ("inferior", class_run, detach_inferior_command, _("\
 Detach from inferior ID."),
@@ -501,4 +1045,13 @@ Kill inferior ID."),
 Use this command to switch between inferiors.\n\
 The new inferior ID must be currently known."),
 	   &cmdlist);
+
+  add_setshow_boolean_cmd ("inferior-events", no_class,
+         &print_inferior_events, _("\
+Set printing of inferior events (e.g., inferior start and exit)."), _("\
+Show printing of inferior events (e.g., inferior start and exit)."), NULL,
+         NULL,
+         show_print_inferior_events,
+         &setprintlist, &showprintlist);
+
 }