* linux-nat.c (kill_lwp): Minor cleanup, move definition of
tkill_failed into ifdef HAVE_TKILL_SYSCALL. Move setting of errno
there too. Delete unnecessary resetting of errno after syscall.
Minor comment changes to match gdbserver/linux-low.c:kill_lwp.
gdbserver/
* linux-low.c (kill_lwp): Use __NR_tkill instead of SYS_tkill.
Move definition of tkill_failed to ifdef __NR_tkill to avoid gcc
warning ifndef __NR_tkill. Move setting of errno there too.
Delete unnecessary resetting of errno after syscall.
Minor comment changes to match gdb/linux-nat.c:kill_lwp.
the pspace doesn't allow breakpoints.
(insert_breakpoint_locations): Remove waiting_for_vfork_done
special case. Expect watchpoints that shouldn't be inserted, to
not be inserted.
* progspace.h (struct program_space) <breakpoints_not_allowed>:
New field.
* infrun.c (handle_inferior_event): Clear it.
* linux-nat.c (linux_child_follow_fork): Set it.
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".
(SYSCALL_SIGTRAP): New.
(status_to_str): Adjust.
(get_pending_status): Pending events in lp->waitstatus don't map
to any signal. Simplify.
(linux_handle_syscall_trap): New.
(linux_handle_extended_wait): When handling PTRACE_EVENT_CLONE
events, use linux_ops->to_resume instead of direct ptrace with
PTRACE_CONT. Remove all TRAP_IS_SYSCALL handling.
(wait_lwp): Handle syscall traps with linux_handle_syscall_trap,
and clear the sysgood bit.
(status_callback): Make it clearer and add comments.
(cancel_breakpoints_callback): Ignore if LP has waitstatus set.
(linux_nat_filter_event): Handle syscall traps with
linux_handle_syscall_trap, and clear the sysgood bit. Move the
check for storing siginfo to after handling extended statuses and
syscall traps. Store status in the lwp object.
(linux_wait_1): Don't swap the pending status out of the lwp
object until after deciding we found an lwp with an interesting
event. Requeue a new pending signal if we find one while getting
rid or a pending SIGSTOP we sent ourselves. Don't clear the
sysgood bit here.
* infrun.c (deal_with_syscall_event): Rename to ...
(handle_syscall_event): ... this. Always context switch and set
stop_pc, even if not catching the syscall. If not catching the
syscall, always resume with keep_going.
(handle_inferior_event): Adjust.
* amd64-linux-tdep.c: Include xml-syscall.h header, define the XML
syscall name for the architecture.
(amd64_linux_get_syscall_number): New function.
(amd64_linux_init_abi): Register the correct functions for syscall
catchpoint; set the correct syscall file name.
* breakpoint.c: New include: xml-syscall.h.
(set_raw_breakpoint_without_location): Setting the parameters
for the catch syscall feature.
(insert_catch_syscall): New.
(remove_catch_syscall): New.
(breakpoint_hit_catch_syscall): New.
(print_it_catch_syscall): New.
(print_one_catch_syscall): New.
(print_mention_catch_syscall): New.
(catch_syscall_breakpoint_ops): New.
(syscall_catchpoint_p): New.
(create_catchpoint_without_mention): New.
(create_catchpoint): Modified in order to use
create_catchpoint_without_mention.
(create_syscall_event_catchpoint): New.
(clean_up_filters): New.
(catch_syscall_split_args): New.
(catch_syscall_command_1): New.
(delete_breakpoint): Add cleanup for catch syscall.
(is_syscall_catchpoint_enabled): New.
(catch_syscall_enabled): New.
(catching_syscall_number): New.
(catch_syscall_completer): New completer function.
(add_catch_command): Add the completer function for catchpoints.
* breakpoint.h (syscalls_to_be_caught): New vector.
(catch_syscall_enabled): New.
(catching_syscall_number): New.
* gdbarch.c: Regenerated.
* gdbarch.h: Regenerated.
* gdbarch.sh: Add syscall catchpoint functions and structures.
(get_syscall_number): New.
(UNKNOWN_SYSCALL): New definition.
* i386-linux-nat.c (i386_linux_resume): Select the proper request
to be made for ptrace() considering if we are catching syscalls
or not.
* i386-linux-tdep.c: Include xml-syscall.h header, define the XML
syscall name for the architecture.
(i386_linux_get_syscall_number): New.
(i386_linux_init_abi): Register the correct functions for syscall
catchpoint; set the correct syscall file name.
* inf-child.c (inf_child_set_syscall_catchpoint): New.
(inf_child_target): Assign default values to target_ops.
* inf-ptrace.c (inf_ptrace_resume): Select the proper request
to be made for ptrace() considering if we are catching syscalls
or not.
* inferior.h (struct inferior): Included new variables
any_syscall_count, syscalls_counts and total_syscalls_count,
used to keep track of requested syscall catchpoints.
* infrun.c (resume): Add syscall catchpoint.
(deal_with_syscall_event): New.
(handle_inferior_event): Add syscall entry/return events.
(inferior_has_called_syscall): New.
* linux-nat.c: Define some helpful variables to track wether we have
support for the needed ptrace option.
(linux_test_for_tracesysgood): New.
(linux_supports_tracesysgood): New.
(linux_enable_tracesysgood): New.
(linux_enable_event_reporting): Save the current used ptrace
options.
(linux_child_post_attach): Calling linux_enable_tracesysgood.
(linux_child_post_startup_inferior): Likewise.
(linux_child_set_syscall_catchpoint): New function.
(linux_handle_extended_wait): Handle the case which the inferior stops
because it has called or returned from a syscall.
(linux_target_install_ops): Install the necessary functions to handle
syscall catchpoints.
* linux-nat.h (struct lwp_info): Include syscall_state into the
structure, which indicates if we are in a syscall entry or return.
* ppc-linux-tdep.c: Include xml-syscall.h header, define the XML
syscall filename for the arch.
(ppc_linux_get_syscall_number): New.
(ppc_linux_init_abi): Register the correct functions for syscall
catchpoint; setting the correct name for the XML syscall file.
* target.c (update_current_target): Update/copy functions related to
syscall catchpoint.
(target_waitstatus_to_string): Add syscall catchpoint entry/return
events.
* target.h (struct target_waitstatus): Add syscall number.
(struct syscall): New struct to hold information about syscalls
in the system.
(struct target_ops): Add ops for syscall catchpoint.
(inferior_has_called_syscall): New.
(target_set_syscall_catchpoint): New.
* xml-support.c (xml_fetch_content_from_file): New function,
transferred from xml-tdesc.c.
* xml-support.h (xml_fetch_content_from_file): New.
* xml-tdesc.c (fetch_xml_from_file): Function removed;
transferred to xml-support.c.
(file_read_description_xml): Updated to use the new
xml_fetch_content_from_file function.
* syscalls/gdb-syscalls.dtd: New definition file for syscall's XML
support.
* syscalls/amd64-linux.xml: New file containing information about
syscalls for GNU/Linux systems that use amd64 architecture.
* syscalls/i386-linux.xml: New file containing information about
syscalls for GNU/Linux systems that use i386 architecture.
* syscalls/ppc-linux.xml: New file containing information about
syscalls for GNU/Linux systems that use PPC architecture.
* syscalls/ppc64-linux.xml: New file containing information about
syscalls for GNU/Linux systems that use PPC64 architecture.
* xml-syscall.c: New file containing functions for manipulating
syscall's XML files.
* xml-syscall.h: New file, exporting the functions above mentioned.
* Makefile.in: Support for relocatable GDB datadir and XML
syscall.
* NEWS: Added information about the catch syscall feature.
* doc/gdb.texinfo (Set Catchpoints): Documentation about the new
feature.
* testsuite/Makefile.in: Inclusion of catch-syscall object.
* testsuite/gdb.base/catch-syscall.c: New file.
* testsuite/gdb.base/catch-syscall.exp: New file.
* linux-nat.c: Include <sys/vfs.h>.
(SPUFS_MAGIC): Define.
(spu_enumerate_spu_ids): New function.
(linux_proc_xfer_spu): New function.
(linux_xfer_partial): Handle TARGET_OBJECT_SPU.
(iterate_over_spus): New function.
(struct linux_spu_corefile_data): New data type.
(linux_spu_corefile_callback): New function.
(linux_spu_make_corefile_notes): New function.
(linux_nat_make_corefile_notes): Call it.
* corelow.c (struct spuid_list): New data type.
(add_to_spuid_list): New function.
(core_xfer_partial): Handle TARGET_OBJECT_SPU.
gdbserver/ChangeLog:
* linux-low.c: Include <sys/stat.h> and <sys/vfs.h>.
(SPUFS_MAGIC): Define.
(spu_enumerate_spu_ids): New function.
(linux_qxfer_spu): New function.
(linux_target_ops): Install linux_qxfer_spu.
Fix memory access from signed 32bit inferior registers on 64bit GDB.
* linux-nat.c (linux_xfer_partial <TARGET_OBJECT_MEMORY>): New variable
addr_bit. Mask OFFSET by the ADDR_BIT width.
gdb/testsuite/
* gdb.arch/amd64-i386-address.exp, gdb.arch/amd64-i386-address.S: New.
2009-07-02 Pedro Alves <pedro@codesourcery.com>
* linux-nat.c (linux_child_follow_fork): If we're staying attached
to the child process, enable event reporting on it. Don't handle
checkpoints here. Instead, add the child fork to the lwp thread
and inferior lists without clobbering the previous inferior. Let
the thread_db layer learn about a new child process, even if
following the parent.
(linux_nat_switch_fork): Delete lwps of the current inferior only,
instead of clearing the whole list. Use thread_change_ptid to
give the core the illusion the new checkpoint is still the same
inferior. Clear the register cache.
(linux_handle_extended_wait): Handle checkpoints here.
(linux_multi_process): Turn on.
* linux-fork.c (struct fork_info) <pc>: Remove field.
(init_fork_list): Do not delete the checkpoint from the inferior
list (it is not there).
(fork_load_infrun_state): Don't switch inferior_ptid here. Pass
the new checkpoint's ptid to linux_nat_switch_fork.
(fork_save_infrun_state): Make static. Don't stop the pc field of
fork_info, it's gone.
(linux_fork_mourn_inferior): Don't delete the checkpoint from the
inferior list, it's not there.
(linux_fork_detach): Ditto.
(delete_fork_command): Replace mention of fork/checkpoint by
checkpoint only.
(detach_fork_command): Likewise. Don't delete the checkpoint from
the inferior list.
(info_forks_command): Adjust.
(restore_detach_fork): Delete.
(checkpointing_pid): New.
(linux_fork_checkpointing_p): New.
(save_detach_fork): Delete.
(checkpoint_command): Delete temp_detach_fork. Don't remove
breakpoints, that's a nop. Store the pid of the process we're
checkpointing, and use make_cleanup_restore_integer to restore it.
Don't reinsert breakpoints here.
(process_command, fork_command): Delete.
(restart_command): Update comments to only mention checkpoints,
not forks.
(_initialize_linux_fork): Delete "fork", "process", "info forks"
commands.
* linux-fork.h (fork_save_infrun_state, fork_list): Delete
declarations.
(linux_fork_checkpointing_p): Declare.
* cli/cli-cmds.c (killlist): New.
* cli/cli-cmds.h (killlist): Declare.
* gdbcmd.h (killlist): Declare.
* inferior.c: Include "gdbthread.h".
(detach_inferior_command, kill_inferior_command)
(inferior_command): New.
(info_inferiors_command): Allow specifying a specific inferior id.
(_initialize_inferiors): Register "inferior", "kill inferior" and
"detach inferior" commands.
* infcmd.c (_initialize_infcmd): Make "kill" a prefix command.
* gdbthread.h (any_thread_of_process): Declare.
* thread.c (any_thread_of_process): New.
* NEWS: Mention multi-inferior debugging. Mention 'info
inferiors', 'inferior', 'detach inferior' and 'kill inferior' as
new commands.
(Removed commands): New section, mentioning that 'info forks',
'fork', 'process', 'delete fork' and 'detach fork' are now gone.
gdb/testsuite/
2009-07-02 Pedro Alves <pedro@codesourcery.com>
* gdb.base/multi-forks.exp: Only run detach-on-fork tests on
linux. Adjust to use "inferior", "info inferiors", "detach
inferior" and "kill inferior" instead of "restart", "info fork",
"detach fork" and "delete fork".
* gdb.base/ending-run.exp: Spell out "info".
* gdb.base/help.exp: Adjust to use test_prefix_command_help for
the "kill" command.
gdb/doc/
2009-07-02 Pedro Alves <pedro@codesourcery.com>
* gdb.texinfo (Debugging multiple inferiors): Document the
"inferior", "detach inferior" and "kill inferior" commands.
(Debugging Programs with Multiple Processes): Adjust to mention
generic "inferior" commands. Delete mention of "detach fork" and
"delete fork". Cross reference to "Debugging multiple inferiors"
section.
Global renaming of find_thread_pid to find_thread_ptid.
* gdbthread.h (find_thread_ptid): Renamed from find_thread_pid.
* thread.c (find_thread_ptid): Renamed from find_thread_pid.
All callers updated.
gdbserver:
Global renaming of find_thread_pid to find_thread_ptid.
* server.h (find_thread_ptid): Renamed from find_thread_pid.
* inferiors.c (find_thread_ptid): Renamed from find_thread_pid.
All callers updated.
* gdbthread.h (struct thread_info): New `pending_follow' field.
* thread.c (new_thread): New function.
(add_thread_silent): Use it.
* breakpoint.c (internal_breakpoint_number): New global, moved
from inside...
(create_internal_breakpoint): ... this.
(clone_momentary_breakpoint): New.
* breakpoint.h (clone_momentary_breakpoint): Declare.
* infrun.c (nullify_last_target_wait_ptid): Move declaration
higher.
(pending_follow): Delete.
(follow_fork): Handle pending follow fork event here. Moved the
preserving of thread stepping state here.
(resume): Don't handle pending follow fork events here. Only
install the inferior's terminal modes if we're about to resume it.
(proceed): Handle possible pending follow fork events here.
(init_wait_for_inferior): No need to clear pending_follow anymore,
it's gone.
(handle_inferior_event): Adjust to per-thread `pending_follow'.
Call `follow_fork' to handle following the fork. If the
follow-fork is cancelled, stop stepping.
* linux-nat.c (linux_child_follow_fork): Adjust to per-thread
`pending_follow' events. Remove code that handled preserving the
thread stepping state.
* inf-ptrace.c (inf_ptrace_follow_fork): Ditto.
* inf-ttrace.c (inf_ttrace_follow_fork): Ditto.
gdb/testsuite/
* gdb.threads/fork-thread-pending.c: New.
* gdb.threads/fork-thread-pending.exp: New.
(fork_inferior): Call new_tty_postfork after forking adn adding
the child to the inferior list.
* inferior.h (new_tty_prefork, gdb_has_a_terminal): Don't declare
here.
* inflow.c (struct terminal_info): Remove const qualifier from
`run_terminal' field.
(inferior_thisrun_terminal): Tweak comment.
(inflow_inferior_exit): Release the `run_terminal' field.
(copy_terminal_info): New function.
(new_tty_postfork): New function.
* terminal.h (new_tty_prefork, new_tty, new_tty_postfork,
(copy_terminal_info, gdb_has_a_terminal, gdb_setpgid): Declare.
* inf-ptrace.c: Include terminal.h.
(inf_ptrace_follow_fork): Copy the parent's terminal info to the
child.
* linux-nat.c: Include terminal.h.
(linux_child_follow_fork): Copy the parent's terminal info to the
child.
* inf-ttrace.c: Include terminal.h.
(inf_ttrace_follow_fork): Copy the parent's terminal info to the
child.
* linux-nat.c (linux_proc_get_tgid): New.
* linux-thread-db.c (struct thread_db_info): New field
`need_stale_parent_threads_check'.
(add_thread_db_info): Set it.
(find_new_threads_callback): Ignore stale fork parent threads.
(thread_db_resume): New.
(init_thread_db_ops): Install thread_db_resume.
is the first inferior.
(startup_inferior): If the target support multi-process, tell it
to resume only the new process.
* linux-nat.c (num_lwps): Delete global.
(purge_lwp_list): New function.
(num_lwps): New function.
(add_lwp, delete_lwp): Adjust.
(ptid_match): New.
(iterate_over_lwps): Add filter argument. Handle it.
(linux_nat_attach): Remove FIXME note.
(linux_nat_detach): Adjust to iterate over threads of the inferior
we're detaching from. Adjust to num_lwps being a function. Don't
assume the head of the lwp list is the main thread of the process
we're detaching from. Don't destroy the LWP list.
(resume_callback): Add debug output.
(linux_nat_resume): Handle resuming a single inferior. Allow a
wildcard resume in non-stop mode.
(linux_handle_extended_wait): Don't assume inferior_ptid is the
correct inferior of the parent LWP.
(status_callback): Also check lp->waitstatus.
(select_event_lwp): Add new filter parameter. Handle it.
(linux_nat_filter_event): Adjust to num_lwps being a function.
(linux_nat_wait_1): When adding the first lwp of the inferior, use
an is_lwp check instead of checking for the number of lwps.
(linux_nat_wait_1): Handle waiting for a specific tgid. Handle
pending process exit statuses.
(linux_nat_mourn_inferior): Don't destroy all the LWP info.
Instead delete LWPs of the inferior that we're mourning. Don't
unregister from the event loop here.
(linux_nat_pid_to_str): Use `num_lwps'.
(linux_nat_make_corefile_notes): Adjust to walk over lwps of a
single inferior.
(linux_nat_is_async_p): Check if async was masked out.
(linux_multi_process): New global.
(linux_nat_supports_multi_process): New.
(linux_nat_stop_lwp): Remove LWP filtering. It is done by the
caller.
(linux_nat_stop): Adjust to make iterate_over_lwps itself do the
LWP filtering.
(linux_nat_close): New.
(linux_nat_add_target): Register linux_nat_close and
linux_nat_supports_multi_process.
* linux-nat.h (iterate_over_lwps): Add filter argument.
* linux-thread-db.c (thread_db_handle): Delete.
(proc_handle, thread_agent, td_init_p, td_ta_new_p)
(td_ta_map_id2thr_p, td_ta_map_lwp2thr_p, td_ta_thr_iter_p)
(td_ta_event_addr_p, td_ta_set_event_p, td_ta_event_getmsg_p)
(td_thr_validate_p, td_thr_get_info_p, td_thr_event_enable_p)
(td_thr_tls_get_addr_p, td_create_bp_addr, td_death_bp_addr): No
longer globals, moved to...
(struct thread_db_info): ... this new structure.
(thread_db_list): New.
(add_thread_db_info, get_thread_db_info, delete_thread_db_info):
New.
(have_threads_callback): Filter out threads of all inferiors but
the one specified by the ARGS argument.
(have_threads): Add ptid argument specifying the inferior we're
interested in. Handle it.
(struct thread_get_info_inout): New.
(thread_get_info_callback, thread_from_lwp): Adjust to use it.
(thread_db_attach_lwp): Check that inferior of the passed in
thread is using thread-db. Adjust.
(enable_thread_event): Remove thread_agent parameter. Instead,
get it from the per-inferior thread-db info.
(dladdr_to_soname): Move higher up.
(enable_thread_event_reporting): Adjust to use per-inferior
thread-db info.
(try_thread_db_load_1): Replace `handle' parameter by a
thread_db_info parameter. Adjust to use per-inferior thread-db
info.
(try_thread_db_load): Adjust to use per-inferior thread-db info.
(thread_db_load, disable_thread_event_reporting): Ditto.
(check_for_thread_db): Remove conditional reporting of which
libthread_db is in use.
(thread_db_new_objfile): Add comment about inferior_ptid.
(attach_thread): Adjust to use per-inferior thread-db info.
(thread_db_detach): Adjust to use per-inferior thread-db info.
Remove thread event breakpoints of the current inferior. Only
unpush the thread-db target if there are no more processes using
it.
(check_event): Adjust to use per-inferior thread-db info.
(thread_db_wait): Adjust to use per-inferior thread-db info. Only
unpush the thread-db target if there are no more processes using
it.
(thread_db_mourn_inferior): Adjust to use per-inferior thread-db
info. Mark breakpoints of the current inferior out before
deleting them. Only unpush the thread-db target if there are no
more processes using it.
(find_new_threads_callback): Adjust to use per-inferior thread_db
info.
(thread_db_find_new_threads_1): Add new ptid argument. Adjust to
use per-inferior thread-db info.
(thread_db_find_new_threads): Adjust to use per-inferior thread-db
info.
(thread_db_get_thread_local_address): Adjust.
(thread_db_get_ada_task_ptid): Adjust.
* inf-ptrace.c (inf_ptrace_mourn_inferior): Only unpush the target
if there no more processes left to debug.
* thread.c (set_running, set_executing): Handle resuming all
threads of a single inferior.
* mi/mi-interp.c (mi_output_running_pid): New.
(mi_inferior_count): New.
(mi_on_resume): For backwards compatibility, if resuming all
threads of an inferior, and there is only one inferior, output
"all".
2009-05-17 Pedro Alves <pedro@codesourcery.com>
* infrun.c (handle_inferior_event): When handling a
TARGET_WAITKIND_FORKED, detach breakpoints from the fork child
immediatelly.
* linux-nat.c (linux_child_follow_fork): Only detach breakpoint
from the child if vforking.
* inf-ptrace.c (inf_ptrace_follow_fork): No need to detach
breakpoints from the child here.
gdb/testsuite/
2009-05-17 Pedro Alves <pedro@codesourcery.com>
* gdb.base/foll-fork.c: Include stdlib.h. Add markers for
`gdb_get_line_number'. Call `callee' in both parent and child.
* gdb.base/foll-fork.exp (catch_fork_child_follow): Use
`gdb_get_line_number' instead of hardcoding line numbers.
(catch_fork_unpatch_child): New procedure to test detaching
breakpoints from child fork.
(tcatch_fork_parent_follow): Use `gdb_get_line_number' instead of
hardcoding line numbers.
(do_fork_tests): Run `catch_fork_unpatch_child'.
Silence a few -Wmissing-prototypes warnings.
PR build/9877:
* amd64-nat.c: Include "amd64-nat.h".
* fork-child.c (_initialize_fork_child): Ditto.
* gcore.c (_initialize_gcore): Ditto.
* inf-ptrace.c: Include "inf-ptrace.h".
(inf_ptrace_store_registers): Make it static.
* linux-nat.c (linux_nat_terminal_ours): Make it static.
(_initialize_linux_nat): Declare before definition.
* linux-tdep.c: Include "linux-tdep.h".
* linux-thread-db.c (_initialize_thread_db): Declare before
definition.
* proc-service.c (_initialize_proc_service): Ditto.
* remote.c (remote_send_printf): Make it static.
* solib.c: Include "solib.h".
* symfile-mem.c (_initialize_symfile_mem): Declare before
definition.
* ada-lang.c (ada_la_decode, ada_match_name)
(ada_suppress_symbol_printing, ada_is_array_type)
(ada_value_ptr_subscript, ada_array_length)
(ada_to_static_fixed_value): Make them static.
(_initialize_ada_language): Declare before definition.
* ada-tasks.c (ada_get_task_number, ada_get_environment_task)
(ada_task_list_changed, ada_new_objfile_observer): Make them
static.
(_initialize_tasks): Declare before definition.
* addrmap.c (_initialize_addrmap): Declare before definition.
* auxv.c (default_auxv_parse): Make it static.
* bfd-target.c (target_bfd_xfer_partial, target_bfd_xclose): Make
them static.
* breakpoint.c (remove_sal): Add line break.
(expand_line_sal_maybe): Make it static.
* cp-name-parser.y: Include "cp-support.h".
* cp-valprint.c (cp_find_class_member): Make it static.
* eval.c (value_f90_subarray): Ditto.
* exceptions.c (print_any_exception): Ditto.
* findcmd.c (_initialize_mem_search): Declare before definition.
* frame.c (frame_observer_target_changed): Make it static.
* gnu-v3-abi.c (gnuv3_find_method_in): Make it static.
* inf-child.c: Include "inf-child.h".
* inferior.h (valid_inferior_id): Rename to ...
(valid_gdb_inferior_id): ... this.
* infrun.c (infrun_thread_stop_requested, siginfo_make_value):
Make them static.
* jv-lang.c (java_language_arch_info): Make it static.
* m2-typeprint.c (m2_get_discrete_bounds): Ditto.
* osdata.c (info_osdata_command): Make it static.
* regcache.c (regcache_observer_target_changed): Make it static.
* reverse.c (_initialize_reverse): Declare before definition.
* stabsread.c (cleanup_undefined_types_noname)
(cleanup_undefined_types_1): Make them static.
* symfile.c (place_section): Make it static.
* symtab.c (find_pc_sect_psymtab_closer): Make it static.
* target-descriptions.c (_initialize_target_descriptions): Declare
before definition.
* target.c (default_get_ada_task_ptid, find_default_can_async_p)
(find_default_is_async_p, find_default_supports_non_stop): Make
them static.
(target_supports_non_stop): Add prototype.
(dummy_pid_to_str): Make it static.
* utils.c (_initialize_utils): Declare before definition.
* ada-exp.y (_initialize_ada_exp): Declare before definition.
* solib-svr4.c (HAS_LM_DYNAMIC_FROM_LINK_MAP): Add a prototype.
* target.h (struct target_ops): Add a prototype to the
to_can_execute_reverse callback.
* macroscope.c (_initialize_macroscope): Declare before definition.
* cp-namespace.c (_initialize_cp_namespace): Declare before definition.
* python/python.c (_initialize_python): Declare before definition.
* tui/tui-command.c: Include "tui/tui-command.h".
* tui/tui-data.c (init_content_element, init_win_info): Make them
static.
* tui/tui-disasm.c: Include "tui/tui-disasm.h".
* tui/tui-interp.c (_initialize_tui_interp): Declare before
definition.
* tui/tui-layout.c: Include "tui/tui-layout.h".
(_initialize_tui_layout): Declare before definition.
* tui/tui-regs.c: Include "tui/tui-regs.h".
(tui_display_reg_element_at_line): Make it static.
(_initialize_tui_regs): Declare before definition.
* tui/tui-stack.c (_initialize_tui_stack): Declare before
definition.
* tui/tui-win.c: Include "tui/tui-win.h".
(_initialize_tui_win): Declare before definition.
(tui_sigwinch_handler): Make it static. Wrap in ifdef SIGWINCH.
* tui/tui-win.h (tui_sigwinch_handler): Delete declaration.
(tui_get_cmd_list): Add a prototype.
* tui/tui-windata.c: Include tui-windata.h.
* tui/tui-wingeneral.c (box_win): Make it static.
* cli/cli-logging.c (show_logging_command): Make it static.
(_initialize_cli_logging): Declare before definition.
* mi/mi-common.c (_initialize_gdb_mi_common): Declare before
definition.
parent to the child.
* inf-ttrace.c (inf_ttrace_follow_fork): Likewise.
* inf-ptrace.c (inf_ptrace_follow_fork): Likewise. Use
remove_breakpoints to remove breakpoints from the parent.
attribute in GLIBC 2.8.
* cli/cli-cmds.c (pwd_command): Check return value from getcwd.
* inflow.c (check_syscall): New function.
(new_tty): Use check_syscall to check return values from open and dup.
* linux-nat.c (linux_nat_info_proc_cmd): Check return value from fgets.
* main.c (captured_main): Call cwd after setting up gdb_stderr;
check for errors from getcwd.
* mi/mi-cmd-env.c (mi_cmd_env_pwd): Check return value from getcwd.
* ui-file.c (stdio_file_write): Ignore return value from fwrite.
(stdio_file_fputs): Same.
* utils.c (internal_vproblem): abort if last-ditch error message
write fails.
* linux-fork.h (linux_fork_detach): Declare.
* linux-nat.c (linux_child_follow_fork): When following the fork
child, add the child inferior before possibly detaching from the
parent. Don't reinstall ourselves.
(linux_nat_detach): Call linux_fork_detach if there are other
forks to debug.
* linux-thread-db.c (thread_db_detach): Don't call
target_mourn_inferior. Instead inline the necessary bits.
* inf-ptrace.c (inf_ptrace_detach): Don't unpush the target if
there are other inferiors to debug.
and not detaching the parent, also add the child fork to the fork
list.
* linux-fork.c (linux_fork_context): Remove dead error call.
Assert that the incoming newfp argument is not null. Do not add a
new fork for inferior_ptid. Assert that there is one already.
