| /* Target-struct-independent code to start (run) and stop an inferior |
| process. |
| |
| Copyright (C) 1986-2012 Free Software Foundation, Inc. |
| |
| This file is part of GDB. |
| |
| This program is free software; you can redistribute it and/or modify |
| it under the terms of the GNU General Public License as published by |
| the Free Software Foundation; either version 3 of the License, or |
| (at your option) any later version. |
| |
| This program is distributed in the hope that it will be useful, |
| but WITHOUT ANY WARRANTY; without even the implied warranty of |
| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| GNU General Public License for more details. |
| |
| You should have received a copy of the GNU General Public License |
| along with this program. If not, see <http://www.gnu.org/licenses/>. */ |
| |
| #include "defs.h" |
| #include "gdb_string.h" |
| #include <ctype.h> |
| #include "symtab.h" |
| #include "frame.h" |
| #include "inferior.h" |
| #include "exceptions.h" |
| #include "breakpoint.h" |
| #include "gdb_wait.h" |
| #include "gdbcore.h" |
| #include "gdbcmd.h" |
| #include "cli/cli-script.h" |
| #include "target.h" |
| #include "gdbthread.h" |
| #include "annotate.h" |
| #include "symfile.h" |
| #include "top.h" |
| #include <signal.h> |
| #include "inf-loop.h" |
| #include "regcache.h" |
| #include "value.h" |
| #include "observer.h" |
| #include "language.h" |
| #include "solib.h" |
| #include "main.h" |
| #include "dictionary.h" |
| #include "block.h" |
| #include "gdb_assert.h" |
| #include "mi/mi-common.h" |
| #include "event-top.h" |
| #include "record.h" |
| #include "inline-frame.h" |
| #include "jit.h" |
| #include "tracepoint.h" |
| #include "continuations.h" |
| #include "interps.h" |
| #include "skip.h" |
| #include "probe.h" |
| #include "objfiles.h" |
| |
| /* Prototypes for local functions */ |
| |
| static void signals_info (char *, int); |
| |
| static void handle_command (char *, int); |
| |
| static void sig_print_info (enum gdb_signal); |
| |
| static void sig_print_header (void); |
| |
| static void resume_cleanups (void *); |
| |
| static int hook_stop_stub (void *); |
| |
| static int restore_selected_frame (void *); |
| |
| static int follow_fork (void); |
| |
| static void set_schedlock_func (char *args, int from_tty, |
| struct cmd_list_element *c); |
| |
| static int currently_stepping (struct thread_info *tp); |
| |
| static int currently_stepping_or_nexting_callback (struct thread_info *tp, |
| void *data); |
| |
| static void xdb_handle_command (char *args, int from_tty); |
| |
| static int prepare_to_proceed (int); |
| |
| static void print_exited_reason (int exitstatus); |
| |
| static void print_signal_exited_reason (enum gdb_signal siggnal); |
| |
| static void print_no_history_reason (void); |
| |
| static void print_signal_received_reason (enum gdb_signal siggnal); |
| |
| static void print_end_stepping_range_reason (void); |
| |
| void _initialize_infrun (void); |
| |
| void nullify_last_target_wait_ptid (void); |
| |
| static void insert_hp_step_resume_breakpoint_at_frame (struct frame_info *); |
| |
| static void insert_step_resume_breakpoint_at_caller (struct frame_info *); |
| |
| static void insert_longjmp_resume_breakpoint (struct gdbarch *, CORE_ADDR); |
| |
| /* When set, stop the 'step' command if we enter a function which has |
| no line number information. The normal behavior is that we step |
| over such function. */ |
| int step_stop_if_no_debug = 0; |
| static void |
| show_step_stop_if_no_debug (struct ui_file *file, int from_tty, |
| struct cmd_list_element *c, const char *value) |
| { |
| fprintf_filtered (file, _("Mode of the step operation is %s.\n"), value); |
| } |
| |
| /* In asynchronous mode, but simulating synchronous execution. */ |
| |
| int sync_execution = 0; |
| |
| /* wait_for_inferior and normal_stop use this to notify the user |
| when the inferior stopped in a different thread than it had been |
| running in. */ |
| |
| static ptid_t previous_inferior_ptid; |
| |
| /* Default behavior is to detach newly forked processes (legacy). */ |
| int detach_fork = 1; |
| |
| int debug_displaced = 0; |
| static void |
| show_debug_displaced (struct ui_file *file, int from_tty, |
| struct cmd_list_element *c, const char *value) |
| { |
| fprintf_filtered (file, _("Displace stepping debugging is %s.\n"), value); |
| } |
| |
| int debug_infrun = 0; |
| static void |
| show_debug_infrun (struct ui_file *file, int from_tty, |
| struct cmd_list_element *c, const char *value) |
| { |
| fprintf_filtered (file, _("Inferior debugging is %s.\n"), value); |
| } |
| |
| |
| /* Support for disabling address space randomization. */ |
| |
| int disable_randomization = 1; |
| |
| static void |
| show_disable_randomization (struct ui_file *file, int from_tty, |
| struct cmd_list_element *c, const char *value) |
| { |
| if (target_supports_disable_randomization ()) |
| fprintf_filtered (file, |
| _("Disabling randomization of debuggee's " |
| "virtual address space is %s.\n"), |
| value); |
| else |
| fputs_filtered (_("Disabling randomization of debuggee's " |
| "virtual address space is unsupported on\n" |
| "this platform.\n"), file); |
| } |
| |
| static void |
| set_disable_randomization (char *args, int from_tty, |
| struct cmd_list_element *c) |
| { |
| if (!target_supports_disable_randomization ()) |
| error (_("Disabling randomization of debuggee's " |
| "virtual address space is unsupported on\n" |
| "this platform.")); |
| } |
| |
| |
| /* If the program uses ELF-style shared libraries, then calls to |
| functions in shared libraries go through stubs, which live in a |
| table called the PLT (Procedure Linkage Table). The first time the |
| function is called, the stub sends control to the dynamic linker, |
| which looks up the function's real address, patches the stub so |
| that future calls will go directly to the function, and then passes |
| control to the function. |
| |
| If we are stepping at the source level, we don't want to see any of |
| this --- we just want to skip over the stub and the dynamic linker. |
| The simple approach is to single-step until control leaves the |
| dynamic linker. |
| |
| However, on some systems (e.g., Red Hat's 5.2 distribution) the |
| dynamic linker calls functions in the shared C library, so you |
| can't tell from the PC alone whether the dynamic linker is still |
| running. In this case, we use a step-resume breakpoint to get us |
| past the dynamic linker, as if we were using "next" to step over a |
| function call. |
| |
| in_solib_dynsym_resolve_code() says whether we're in the dynamic |
| linker code or not. Normally, this means we single-step. However, |
| if SKIP_SOLIB_RESOLVER then returns non-zero, then its value is an |
| address where we can place a step-resume breakpoint to get past the |
| linker's symbol resolution function. |
| |
| in_solib_dynsym_resolve_code() can generally be implemented in a |
| pretty portable way, by comparing the PC against the address ranges |
| of the dynamic linker's sections. |
| |
| SKIP_SOLIB_RESOLVER is generally going to be system-specific, since |
| it depends on internal details of the dynamic linker. It's usually |
| not too hard to figure out where to put a breakpoint, but it |
| certainly isn't portable. SKIP_SOLIB_RESOLVER should do plenty of |
| sanity checking. If it can't figure things out, returning zero and |
| getting the (possibly confusing) stepping behavior is better than |
| signalling an error, which will obscure the change in the |
| inferior's state. */ |
| |
| /* This function returns TRUE if pc is the address of an instruction |
| that lies within the dynamic linker (such as the event hook, or the |
| dld itself). |
| |
| This function must be used only when a dynamic linker event has |
| been caught, and the inferior is being stepped out of the hook, or |
| undefined results are guaranteed. */ |
| |
| #ifndef SOLIB_IN_DYNAMIC_LINKER |
| #define SOLIB_IN_DYNAMIC_LINKER(pid,pc) 0 |
| #endif |
| |
| /* "Observer mode" is somewhat like a more extreme version of |
| non-stop, in which all GDB operations that might affect the |
| target's execution have been disabled. */ |
| |
| static int non_stop_1 = 0; |
| |
| int observer_mode = 0; |
| static int observer_mode_1 = 0; |
| |
| static void |
| set_observer_mode (char *args, int from_tty, |
| struct cmd_list_element *c) |
| { |
| extern int pagination_enabled; |
| |
| if (target_has_execution) |
| { |
| observer_mode_1 = observer_mode; |
| error (_("Cannot change this setting while the inferior is running.")); |
| } |
| |
| observer_mode = observer_mode_1; |
| |
| may_write_registers = !observer_mode; |
| may_write_memory = !observer_mode; |
| may_insert_breakpoints = !observer_mode; |
| may_insert_tracepoints = !observer_mode; |
| /* We can insert fast tracepoints in or out of observer mode, |
| but enable them if we're going into this mode. */ |
| if (observer_mode) |
| may_insert_fast_tracepoints = 1; |
| may_stop = !observer_mode; |
| update_target_permissions (); |
| |
| /* Going *into* observer mode we must force non-stop, then |
| going out we leave it that way. */ |
| if (observer_mode) |
| { |
| target_async_permitted = 1; |
| pagination_enabled = 0; |
| non_stop = non_stop_1 = 1; |
| } |
| |
| if (from_tty) |
| printf_filtered (_("Observer mode is now %s.\n"), |
| (observer_mode ? "on" : "off")); |
| } |
| |
| static void |
| show_observer_mode (struct ui_file *file, int from_tty, |
| struct cmd_list_element *c, const char *value) |
| { |
| fprintf_filtered (file, _("Observer mode is %s.\n"), value); |
| } |
| |
| /* This updates the value of observer mode based on changes in |
| permissions. Note that we are deliberately ignoring the values of |
| may-write-registers and may-write-memory, since the user may have |
| reason to enable these during a session, for instance to turn on a |
| debugging-related global. */ |
| |
| void |
| update_observer_mode (void) |
| { |
| int newval; |
| |
| newval = (!may_insert_breakpoints |
| && !may_insert_tracepoints |
| && may_insert_fast_tracepoints |
| && !may_stop |
| && non_stop); |
| |
| /* Let the user know if things change. */ |
| if (newval != observer_mode) |
| printf_filtered (_("Observer mode is now %s.\n"), |
| (newval ? "on" : "off")); |
| |
| observer_mode = observer_mode_1 = newval; |
| } |
| |
| /* Tables of how to react to signals; the user sets them. */ |
| |
| static unsigned char *signal_stop; |
| static unsigned char *signal_print; |
| static unsigned char *signal_program; |
| |
| /* Table of signals that the target may silently handle. |
| This is automatically determined from the flags above, |
| and simply cached here. */ |
| static unsigned char *signal_pass; |
| |
| #define SET_SIGS(nsigs,sigs,flags) \ |
| do { \ |
| int signum = (nsigs); \ |
| while (signum-- > 0) \ |
| if ((sigs)[signum]) \ |
| (flags)[signum] = 1; \ |
| } while (0) |
| |
| #define UNSET_SIGS(nsigs,sigs,flags) \ |
| do { \ |
| int signum = (nsigs); \ |
| while (signum-- > 0) \ |
| if ((sigs)[signum]) \ |
| (flags)[signum] = 0; \ |
| } while (0) |
| |
| /* Update the target's copy of SIGNAL_PROGRAM. The sole purpose of |
| this function is to avoid exporting `signal_program'. */ |
| |
| void |
| update_signals_program_target (void) |
| { |
| target_program_signals ((int) GDB_SIGNAL_LAST, signal_program); |
| } |
| |
| /* Value to pass to target_resume() to cause all threads to resume. */ |
| |
| #define RESUME_ALL minus_one_ptid |
| |
| /* Command list pointer for the "stop" placeholder. */ |
| |
| static struct cmd_list_element *stop_command; |
| |
| /* Function inferior was in as of last step command. */ |
| |
| static struct symbol *step_start_function; |
| |
| /* Nonzero if we want to give control to the user when we're notified |
| of shared library events by the dynamic linker. */ |
| int stop_on_solib_events; |
| static void |
| show_stop_on_solib_events (struct ui_file *file, int from_tty, |
| struct cmd_list_element *c, const char *value) |
| { |
| fprintf_filtered (file, _("Stopping for shared library events is %s.\n"), |
| value); |
| } |
| |
| /* Nonzero means expecting a trace trap |
| and should stop the inferior and return silently when it happens. */ |
| |
| int stop_after_trap; |
| |
| /* Save register contents here when executing a "finish" command or are |
| about to pop a stack dummy frame, if-and-only-if proceed_to_finish is set. |
| Thus this contains the return value from the called function (assuming |
| values are returned in a register). */ |
| |
| struct regcache *stop_registers; |
| |
| /* Nonzero after stop if current stack frame should be printed. */ |
| |
| static int stop_print_frame; |
| |
| /* This is a cached copy of the pid/waitstatus of the last event |
| returned by target_wait()/deprecated_target_wait_hook(). This |
| information is returned by get_last_target_status(). */ |
| static ptid_t target_last_wait_ptid; |
| static struct target_waitstatus target_last_waitstatus; |
| |
| static void context_switch (ptid_t ptid); |
| |
| void init_thread_stepping_state (struct thread_info *tss); |
| |
| void init_infwait_state (void); |
| |
| static const char follow_fork_mode_child[] = "child"; |
| static const char follow_fork_mode_parent[] = "parent"; |
| |
| static const char *const follow_fork_mode_kind_names[] = { |
| follow_fork_mode_child, |
| follow_fork_mode_parent, |
| NULL |
| }; |
| |
| static const char *follow_fork_mode_string = follow_fork_mode_parent; |
| static void |
| show_follow_fork_mode_string (struct ui_file *file, int from_tty, |
| struct cmd_list_element *c, const char *value) |
| { |
| fprintf_filtered (file, |
| _("Debugger response to a program " |
| "call of fork or vfork is \"%s\".\n"), |
| value); |
| } |
| |
| |
| /* Tell the target to follow the fork we're stopped at. Returns true |
| if the inferior should be resumed; false, if the target for some |
| reason decided it's best not to resume. */ |
| |
| static int |
| follow_fork (void) |
| { |
| int follow_child = (follow_fork_mode_string == follow_fork_mode_child); |
| int should_resume = 1; |
| struct thread_info *tp; |
| |
| /* Copy user stepping state to the new inferior thread. FIXME: the |
| followed fork child thread should have a copy of most of the |
| parent thread structure's run control related fields, not just these. |
| Initialized to avoid "may be used uninitialized" warnings from gcc. */ |
| struct breakpoint *step_resume_breakpoint = NULL; |
| struct breakpoint *exception_resume_breakpoint = NULL; |
| CORE_ADDR step_range_start = 0; |
| CORE_ADDR step_range_end = 0; |
| struct frame_id step_frame_id = { 0 }; |
| |
| if (!non_stop) |
| { |
| ptid_t wait_ptid; |
| struct target_waitstatus wait_status; |
| |
| /* Get the last target status returned by target_wait(). */ |
| get_last_target_status (&wait_ptid, &wait_status); |
| |
| /* If not stopped at a fork event, then there's nothing else to |
| do. */ |
| if (wait_status.kind != TARGET_WAITKIND_FORKED |
| && wait_status.kind != TARGET_WAITKIND_VFORKED) |
| return 1; |
| |
| /* Check if we switched over from WAIT_PTID, since the event was |
| reported. */ |
| if (!ptid_equal (wait_ptid, minus_one_ptid) |
| && !ptid_equal (inferior_ptid, wait_ptid)) |
| { |
| /* We did. Switch back to WAIT_PTID thread, to tell the |
| target to follow it (in either direction). We'll |
| afterwards refuse to resume, and inform the user what |
| happened. */ |
| switch_to_thread (wait_ptid); |
| should_resume = 0; |
| } |
| } |
| |
| tp = inferior_thread (); |
| |
| /* If there were any forks/vforks that were caught and are now to be |
| followed, then do so now. */ |
| switch (tp->pending_follow.kind) |
| { |
| case TARGET_WAITKIND_FORKED: |
| case TARGET_WAITKIND_VFORKED: |
| { |
| ptid_t parent, child; |
| |
| /* If the user did a next/step, etc, over a fork call, |
| preserve the stepping state in the fork child. */ |
| if (follow_child && should_resume) |
| { |
| step_resume_breakpoint = clone_momentary_breakpoint |
| (tp->control.step_resume_breakpoint); |
| step_range_start = tp->control.step_range_start; |
| step_range_end = tp->control.step_range_end; |
| step_frame_id = tp->control.step_frame_id; |
| exception_resume_breakpoint |
| = clone_momentary_breakpoint (tp->control.exception_resume_breakpoint); |
| |
| /* For now, delete the parent's sr breakpoint, otherwise, |
| parent/child sr breakpoints are considered duplicates, |
| and the child version will not be installed. Remove |
| this when the breakpoints module becomes aware of |
| inferiors and address spaces. */ |
| delete_step_resume_breakpoint (tp); |
| tp->control.step_range_start = 0; |
| tp->control.step_range_end = 0; |
| tp->control.step_frame_id = null_frame_id; |
| delete_exception_resume_breakpoint (tp); |
| } |
| |
| parent = inferior_ptid; |
| child = tp->pending_follow.value.related_pid; |
| |
| /* Tell the target to do whatever is necessary to follow |
| either parent or child. */ |
| if (target_follow_fork (follow_child)) |
| { |
| /* Target refused to follow, or there's some other reason |
| we shouldn't resume. */ |
| should_resume = 0; |
| } |
| else |
| { |
| /* This pending follow fork event is now handled, one way |
| or another. The previous selected thread may be gone |
| from the lists by now, but if it is still around, need |
| to clear the pending follow request. */ |
| tp = find_thread_ptid (parent); |
| if (tp) |
| tp->pending_follow.kind = TARGET_WAITKIND_SPURIOUS; |
| |
| /* This makes sure we don't try to apply the "Switched |
| over from WAIT_PID" logic above. */ |
| nullify_last_target_wait_ptid (); |
| |
| /* If we followed the child, switch to it... */ |
| if (follow_child) |
| { |
| switch_to_thread (child); |
| |
| /* ... and preserve the stepping state, in case the |
| user was stepping over the fork call. */ |
| if (should_resume) |
| { |
| tp = inferior_thread (); |
| tp->control.step_resume_breakpoint |
| = step_resume_breakpoint; |
| tp->control.step_range_start = step_range_start; |
| tp->control.step_range_end = step_range_end; |
| tp->control.step_frame_id = step_frame_id; |
| tp->control.exception_resume_breakpoint |
| = exception_resume_breakpoint; |
| } |
| else |
| { |
| /* If we get here, it was because we're trying to |
| resume from a fork catchpoint, but, the user |
| has switched threads away from the thread that |
| forked. In that case, the resume command |
| issued is most likely not applicable to the |
| child, so just warn, and refuse to resume. */ |
| warning (_("Not resuming: switched threads " |
| "before following fork child.\n")); |
| } |
| |
| /* Reset breakpoints in the child as appropriate. */ |
| follow_inferior_reset_breakpoints (); |
| } |
| else |
| switch_to_thread (parent); |
| } |
| } |
| break; |
| case TARGET_WAITKIND_SPURIOUS: |
| /* Nothing to follow. */ |
| break; |
| default: |
| internal_error (__FILE__, __LINE__, |
| "Unexpected pending_follow.kind %d\n", |
| tp->pending_follow.kind); |
| break; |
| } |
| |
| return should_resume; |
| } |
| |
| void |
| follow_inferior_reset_breakpoints (void) |
| { |
| struct thread_info *tp = inferior_thread (); |
| |
| /* Was there a step_resume breakpoint? (There was if the user |
| did a "next" at the fork() call.) If so, explicitly reset its |
| thread number. |
| |
| step_resumes are a form of bp that are made to be per-thread. |
| Since we created the step_resume bp when the parent process |
| was being debugged, and now are switching to the child process, |
| from the breakpoint package's viewpoint, that's a switch of |
| "threads". We must update the bp's notion of which thread |
| it is for, or it'll be ignored when it triggers. */ |
| |
| if (tp->control.step_resume_breakpoint) |
| breakpoint_re_set_thread (tp->control.step_resume_breakpoint); |
| |
| if (tp->control.exception_resume_breakpoint) |
| breakpoint_re_set_thread (tp->control.exception_resume_breakpoint); |
| |
| /* Reinsert all breakpoints in the child. The user may have set |
| breakpoints after catching the fork, in which case those |
| were never set in the child, but only in the parent. This makes |
| sure the inserted breakpoints match the breakpoint list. */ |
| |
| breakpoint_re_set (); |
| insert_breakpoints (); |
| } |
| |
| /* The child has exited or execed: resume threads of the parent the |
| user wanted to be executing. */ |
| |
| static int |
| proceed_after_vfork_done (struct thread_info *thread, |
| void *arg) |
| { |
| int pid = * (int *) arg; |
| |
| if (ptid_get_pid (thread->ptid) == pid |
| && is_running (thread->ptid) |
| && !is_executing (thread->ptid) |
| && !thread->stop_requested |
| && thread->suspend.stop_signal == GDB_SIGNAL_0) |
| { |
| if (debug_infrun) |
| fprintf_unfiltered (gdb_stdlog, |
| "infrun: resuming vfork parent thread %s\n", |
| target_pid_to_str (thread->ptid)); |
| |
| switch_to_thread (thread->ptid); |
| clear_proceed_status (); |
| proceed ((CORE_ADDR) -1, GDB_SIGNAL_DEFAULT, 0); |
| } |
| |
| return 0; |
| } |
| |
| /* Called whenever we notice an exec or exit event, to handle |
| detaching or resuming a vfork parent. */ |
| |
| static void |
| handle_vfork_child_exec_or_exit (int exec) |
| { |
| struct inferior *inf = current_inferior (); |
| |
| if (inf->vfork_parent) |
| { |
| int resume_parent = -1; |
| |
| /* This exec or exit marks the end of the shared memory region |
| between the parent and the child. If the user wanted to |
| detach from the parent, now is the time. */ |
| |
| if (inf->vfork_parent->pending_detach) |
| { |
| struct thread_info *tp; |
| struct cleanup *old_chain; |
| struct program_space *pspace; |
| struct address_space *aspace; |
| |
| /* follow-fork child, detach-on-fork on. */ |
| |
| old_chain = make_cleanup_restore_current_thread (); |
| |
| /* We're letting loose of the parent. */ |
| tp = any_live_thread_of_process (inf->vfork_parent->pid); |
| switch_to_thread (tp->ptid); |
| |
| /* We're about to detach from the parent, which implicitly |
| removes breakpoints from its address space. There's a |
| catch here: we want to reuse the spaces for the child, |
| but, parent/child are still sharing the pspace at this |
| point, although the exec in reality makes the kernel give |
| the child a fresh set of new pages. The problem here is |
| that the breakpoints module being unaware of this, would |
| likely chose the child process to write to the parent |
| address space. Swapping the child temporarily away from |
| the spaces has the desired effect. Yes, this is "sort |
| of" a hack. */ |
| |
| pspace = inf->pspace; |
| aspace = inf->aspace; |
| inf->aspace = NULL; |
| inf->pspace = NULL; |
| |
| if (debug_infrun || info_verbose) |
| { |
| target_terminal_ours (); |
| |
| if (exec) |
| fprintf_filtered (gdb_stdlog, |
| "Detaching vfork parent process " |
| "%d after child exec.\n", |
| inf->vfork_parent->pid); |
| else |
| fprintf_filtered (gdb_stdlog, |
| "Detaching vfork parent process " |
| "%d after child exit.\n", |
| inf->vfork_parent->pid); |
| } |
| |
| target_detach (NULL, 0); |
| |
| /* Put it back. */ |
| inf->pspace = pspace; |
| inf->aspace = aspace; |
| |
| do_cleanups (old_chain); |
| } |
| else if (exec) |
| { |
| /* We're staying attached to the parent, so, really give the |
| child a new address space. */ |
| inf->pspace = add_program_space (maybe_new_address_space ()); |
| inf->aspace = inf->pspace->aspace; |
| inf->removable = 1; |
| set_current_program_space (inf->pspace); |
| |
| resume_parent = inf->vfork_parent->pid; |
| |
| /* Break the bonds. */ |
| inf->vfork_parent->vfork_child = NULL; |
| } |
| else |
| { |
| struct cleanup *old_chain; |
| struct program_space *pspace; |
| |
| /* If this is a vfork child exiting, then the pspace and |
| aspaces were shared with the parent. Since we're |
| reporting the process exit, we'll be mourning all that is |
| found in the address space, and switching to null_ptid, |
| preparing to start a new inferior. But, since we don't |
| want to clobber the parent's address/program spaces, we |
| go ahead and create a new one for this exiting |
| inferior. */ |
| |
| /* Switch to null_ptid, so that clone_program_space doesn't want |
| to read the selected frame of a dead process. */ |
| old_chain = save_inferior_ptid (); |
| inferior_ptid = null_ptid; |
| |
| /* This inferior is dead, so avoid giving the breakpoints |
| module the option to write through to it (cloning a |
| program space resets breakpoints). */ |
| inf->aspace = NULL; |
| inf->pspace = NULL; |
| pspace = add_program_space (maybe_new_address_space ()); |
| set_current_program_space (pspace); |
| inf->removable = 1; |
| inf->symfile_flags = SYMFILE_NO_READ; |
| clone_program_space (pspace, inf->vfork_parent->pspace); |
| inf->pspace = pspace; |
| inf->aspace = pspace->aspace; |
| |
| /* Put back inferior_ptid. We'll continue mourning this |
| inferior. */ |
| do_cleanups (old_chain); |
| |
| resume_parent = inf->vfork_parent->pid; |
| /* Break the bonds. */ |
| inf->vfork_parent->vfork_child = NULL; |
| } |
| |
| inf->vfork_parent = NULL; |
| |
| gdb_assert (current_program_space == inf->pspace); |
| |
| if (non_stop && resume_parent != -1) |
| { |
| /* If the user wanted the parent to be running, let it go |
| free now. */ |
| struct cleanup *old_chain = make_cleanup_restore_current_thread (); |
| |
| if (debug_infrun) |
| fprintf_unfiltered (gdb_stdlog, |
| "infrun: resuming vfork parent process %d\n", |
| resume_parent); |
| |
| iterate_over_threads (proceed_after_vfork_done, &resume_parent); |
| |
| do_cleanups (old_chain); |
| } |
| } |
| } |
| |
| /* Enum strings for "set|show displaced-stepping". */ |
| |
| static const char follow_exec_mode_new[] = "new"; |
| static const char follow_exec_mode_same[] = "same"; |
| static const char *const follow_exec_mode_names[] = |
| { |
| follow_exec_mode_new, |
| follow_exec_mode_same, |
| NULL, |
| }; |
| |
| static const char *follow_exec_mode_string = follow_exec_mode_same; |
| static void |
| show_follow_exec_mode_string (struct ui_file *file, int from_tty, |
| struct cmd_list_element *c, const char *value) |
| { |
| fprintf_filtered (file, _("Follow exec mode is \"%s\".\n"), value); |
| } |
| |
| /* EXECD_PATHNAME is assumed to be non-NULL. */ |
| |
| static void |
| follow_exec (ptid_t pid, char *execd_pathname) |
| { |
| struct thread_info *th = inferior_thread (); |
| struct inferior *inf = current_inferior (); |
| |
| /* This is an exec event that we actually wish to pay attention to. |
| Refresh our symbol table to the newly exec'd program, remove any |
| momentary bp's, etc. |
| |
| If there are breakpoints, they aren't really inserted now, |
| since the exec() transformed our inferior into a fresh set |
| of instructions. |
| |
| We want to preserve symbolic breakpoints on the list, since |
| we have hopes that they can be reset after the new a.out's |
| symbol table is read. |
| |
| However, any "raw" breakpoints must be removed from the list |
| (e.g., the solib bp's), since their address is probably invalid |
| now. |
| |
| And, we DON'T want to call delete_breakpoints() here, since |
| that may write the bp's "shadow contents" (the instruction |
| value that was overwritten witha TRAP instruction). Since |
| we now have a new a.out, those shadow contents aren't valid. */ |
| |
| mark_breakpoints_out (); |
| |
| update_breakpoints_after_exec (); |
| |
| /* If there was one, it's gone now. We cannot truly step-to-next |
| statement through an exec(). */ |
| th->control.step_resume_breakpoint = NULL; |
| th->control.exception_resume_breakpoint = NULL; |
| th->control.step_range_start = 0; |
| th->control.step_range_end = 0; |
| |
| /* The target reports the exec event to the main thread, even if |
| some other thread does the exec, and even if the main thread was |
| already stopped --- if debugging in non-stop mode, it's possible |
| the user had the main thread held stopped in the previous image |
| --- release it now. This is the same behavior as step-over-exec |
| with scheduler-locking on in all-stop mode. */ |
| th->stop_requested = 0; |
| |
| /* What is this a.out's name? */ |
| printf_unfiltered (_("%s is executing new program: %s\n"), |
| target_pid_to_str (inferior_ptid), |
| execd_pathname); |
| |
| /* We've followed the inferior through an exec. Therefore, the |
| inferior has essentially been killed & reborn. */ |
| |
| gdb_flush (gdb_stdout); |
| |
| breakpoint_init_inferior (inf_execd); |
| |
| if (gdb_sysroot && *gdb_sysroot) |
| { |
| char *name = alloca (strlen (gdb_sysroot) |
| + strlen (execd_pathname) |
| + 1); |
| |
| strcpy (name, gdb_sysroot); |
| strcat (name, execd_pathname); |
| execd_pathname = name; |
| } |
| |
| /* Reset the shared library package. This ensures that we get a |
| shlib event when the child reaches "_start", at which point the |
| dld will have had a chance to initialize the child. */ |
| /* Also, loading a symbol file below may trigger symbol lookups, and |
| we don't want those to be satisfied by the libraries of the |
| previous incarnation of this process. */ |
| no_shared_libraries (NULL, 0); |
| |
| if (follow_exec_mode_string == follow_exec_mode_new) |
| { |
| struct program_space *pspace; |
| |
| /* The user wants to keep the old inferior and program spaces |
| around. Create a new fresh one, and switch to it. */ |
| |
| inf = add_inferior (current_inferior ()->pid); |
| pspace = add_program_space (maybe_new_address_space ()); |
| inf->pspace = pspace; |
| inf->aspace = pspace->aspace; |
| |
| exit_inferior_num_silent (current_inferior ()->num); |
| |
| set_current_inferior (inf); |
| set_current_program_space (pspace); |
| } |
| |
| gdb_assert (current_program_space == inf->pspace); |
| |
| /* That a.out is now the one to use. */ |
| exec_file_attach (execd_pathname, 0); |
| |
| /* SYMFILE_DEFER_BP_RESET is used as the proper displacement for PIE |
| (Position Independent Executable) main symbol file will get applied by |
| solib_create_inferior_hook below. breakpoint_re_set would fail to insert |
| the breakpoints with the zero displacement. */ |
| |
| symbol_file_add (execd_pathname, |
| (inf->symfile_flags |
| | SYMFILE_MAINLINE | SYMFILE_DEFER_BP_RESET), |
| NULL, 0); |
| |
| if ((inf->symfile_flags & SYMFILE_NO_READ) == 0) |
| set_initial_language (); |
| |
| #ifdef SOLIB_CREATE_INFERIOR_HOOK |
| SOLIB_CREATE_INFERIOR_HOOK (PIDGET (inferior_ptid)); |
| #else |
| solib_create_inferior_hook (0); |
| #endif |
| |
| jit_inferior_created_hook (); |
| |
| breakpoint_re_set (); |
| |
| /* Reinsert all breakpoints. (Those which were symbolic have |
| been reset to the proper address in the new a.out, thanks |
| to symbol_file_command...). */ |
| insert_breakpoints (); |
| |
| /* The next resume of this inferior should bring it to the shlib |
| startup breakpoints. (If the user had also set bp's on |
| "main" from the old (parent) process, then they'll auto- |
| matically get reset there in the new process.). */ |
| } |
| |
| /* Non-zero if we just simulating a single-step. This is needed |
| because we cannot remove the breakpoints in the inferior process |
| until after the `wait' in `wait_for_inferior'. */ |
| static int singlestep_breakpoints_inserted_p = 0; |
| |
| /* The thread we inserted single-step breakpoints for. */ |
| static ptid_t singlestep_ptid; |
| |
| /* PC when we started this single-step. */ |
| static CORE_ADDR singlestep_pc; |
| |
| /* If another thread hit the singlestep breakpoint, we save the original |
| thread here so that we can resume single-stepping it later. */ |
| static ptid_t saved_singlestep_ptid; |
| static int stepping_past_singlestep_breakpoint; |
| |
| /* If not equal to null_ptid, this means that after stepping over breakpoint |
| is finished, we need to switch to deferred_step_ptid, and step it. |
| |
| The use case is when one thread has hit a breakpoint, and then the user |
| has switched to another thread and issued 'step'. We need to step over |
| breakpoint in the thread which hit the breakpoint, but then continue |
| stepping the thread user has selected. */ |
| static ptid_t deferred_step_ptid; |
| |
| /* Displaced stepping. */ |
| |
| /* In non-stop debugging mode, we must take special care to manage |
| breakpoints properly; in particular, the traditional strategy for |
| stepping a thread past a breakpoint it has hit is unsuitable. |
| 'Displaced stepping' is a tactic for stepping one thread past a |
| breakpoint it has hit while ensuring that other threads running |
| concurrently will hit the breakpoint as they should. |
| |
| The traditional way to step a thread T off a breakpoint in a |
| multi-threaded program in all-stop mode is as follows: |
| |
| a0) Initially, all threads are stopped, and breakpoints are not |
| inserted. |
| a1) We single-step T, leaving breakpoints uninserted. |
| a2) We insert breakpoints, and resume all threads. |
| |
| In non-stop debugging, however, this strategy is unsuitable: we |
| don't want to have to stop all threads in the system in order to |
| continue or step T past a breakpoint. Instead, we use displaced |
| stepping: |
| |
| n0) Initially, T is stopped, other threads are running, and |
| breakpoints are inserted. |
| n1) We copy the instruction "under" the breakpoint to a separate |
| location, outside the main code stream, making any adjustments |
| to the instruction, register, and memory state as directed by |
| T's architecture. |
| n2) We single-step T over the instruction at its new location. |
| n3) We adjust the resulting register and memory state as directed |
| by T's architecture. This includes resetting T's PC to point |
| back into the main instruction stream. |
| n4) We resume T. |
| |
| This approach depends on the following gdbarch methods: |
| |
| - gdbarch_max_insn_length and gdbarch_displaced_step_location |
| indicate where to copy the instruction, and how much space must |
| be reserved there. We use these in step n1. |
| |
| - gdbarch_displaced_step_copy_insn copies a instruction to a new |
| address, and makes any necessary adjustments to the instruction, |
| register contents, and memory. We use this in step n1. |
| |
| - gdbarch_displaced_step_fixup adjusts registers and memory after |
| we have successfuly single-stepped the instruction, to yield the |
| same effect the instruction would have had if we had executed it |
| at its original address. We use this in step n3. |
| |
| - gdbarch_displaced_step_free_closure provides cleanup. |
| |
| The gdbarch_displaced_step_copy_insn and |
| gdbarch_displaced_step_fixup functions must be written so that |
| copying an instruction with gdbarch_displaced_step_copy_insn, |
| single-stepping across the copied instruction, and then applying |
| gdbarch_displaced_insn_fixup should have the same effects on the |
| thread's memory and registers as stepping the instruction in place |
| would have. Exactly which responsibilities fall to the copy and |
| which fall to the fixup is up to the author of those functions. |
| |
| See the comments in gdbarch.sh for details. |
| |
| Note that displaced stepping and software single-step cannot |
| currently be used in combination, although with some care I think |
| they could be made to. Software single-step works by placing |
| breakpoints on all possible subsequent instructions; if the |
| displaced instruction is a PC-relative jump, those breakpoints |
| could fall in very strange places --- on pages that aren't |
| executable, or at addresses that are not proper instruction |
| boundaries. (We do generally let other threads run while we wait |
| to hit the software single-step breakpoint, and they might |
| encounter such a corrupted instruction.) One way to work around |
| this would be to have gdbarch_displaced_step_copy_insn fully |
| simulate the effect of PC-relative instructions (and return NULL) |
| on architectures that use software single-stepping. |
| |
| In non-stop mode, we can have independent and simultaneous step |
| requests, so more than one thread may need to simultaneously step |
| over a breakpoint. The current implementation assumes there is |
| only one scratch space per process. In this case, we have to |
| serialize access to the scratch space. If thread A wants to step |
| over a breakpoint, but we are currently waiting for some other |
| thread to complete a displaced step, we leave thread A stopped and |
| place it in the displaced_step_request_queue. Whenever a displaced |
| step finishes, we pick the next thread in the queue and start a new |
| displaced step operation on it. See displaced_step_prepare and |
| displaced_step_fixup for details. */ |
| |
| struct displaced_step_request |
| { |
| ptid_t ptid; |
| struct displaced_step_request *next; |
| }; |
| |
| /* Per-inferior displaced stepping state. */ |
| struct displaced_step_inferior_state |
| { |
| /* Pointer to next in linked list. */ |
| struct displaced_step_inferior_state *next; |
| |
| /* The process this displaced step state refers to. */ |
| int pid; |
| |
| /* A queue of pending displaced stepping requests. One entry per |
| thread that needs to do a displaced step. */ |
| struct displaced_step_request *step_request_queue; |
| |
| /* If this is not null_ptid, this is the thread carrying out a |
| displaced single-step in process PID. This thread's state will |
| require fixing up once it has completed its step. */ |
| ptid_t step_ptid; |
| |
| /* The architecture the thread had when we stepped it. */ |
| struct gdbarch *step_gdbarch; |
| |
| /* The closure provided gdbarch_displaced_step_copy_insn, to be used |
| for post-step cleanup. */ |
| struct displaced_step_closure *step_closure; |
| |
| /* The address of the original instruction, and the copy we |
| made. */ |
| CORE_ADDR step_original, step_copy; |
| |
| /* Saved contents of copy area. */ |
| gdb_byte *step_saved_copy; |
| }; |
| |
| /* The list of states of processes involved in displaced stepping |
| presently. */ |
| static struct displaced_step_inferior_state *displaced_step_inferior_states; |
| |
| /* Get the displaced stepping state of process PID. */ |
| |
| static struct displaced_step_inferior_state * |
| get_displaced_stepping_state (int pid) |
| { |
| struct displaced_step_inferior_state *state; |
| |
| for (state = displaced_step_inferior_states; |
| state != NULL; |
| state = state->next) |
| if (state->pid == pid) |
| return state; |
| |
| return NULL; |
| } |
| |
| /* Add a new displaced stepping state for process PID to the displaced |
| stepping state list, or return a pointer to an already existing |
| entry, if it already exists. Never returns NULL. */ |
| |
| static struct displaced_step_inferior_state * |
| add_displaced_stepping_state (int pid) |
| { |
| struct displaced_step_inferior_state *state; |
| |
| for (state = displaced_step_inferior_states; |
| state != NULL; |
| state = state->next) |
| if (state->pid == pid) |
| return state; |
| |
| state = xcalloc (1, sizeof (*state)); |
| state->pid = pid; |
| state->next = displaced_step_inferior_states; |
| displaced_step_inferior_states = state; |
| |
| return state; |
| } |
| |
| /* If inferior is in displaced stepping, and ADDR equals to starting address |
| of copy area, return corresponding displaced_step_closure. Otherwise, |
| return NULL. */ |
| |
| struct displaced_step_closure* |
| get_displaced_step_closure_by_addr (CORE_ADDR addr) |
| { |
| struct displaced_step_inferior_state *displaced |
| = get_displaced_stepping_state (ptid_get_pid (inferior_ptid)); |
| |
| /* If checking the mode of displaced instruction in copy area. */ |
| if (displaced && !ptid_equal (displaced->step_ptid, null_ptid) |
| && (displaced->step_copy == addr)) |
| return displaced->step_closure; |
| |
| return NULL; |
| } |
| |
| /* Remove the displaced stepping state of process PID. */ |
| |
| static void |
| remove_displaced_stepping_state (int pid) |
| { |
| struct displaced_step_inferior_state *it, **prev_next_p; |
| |
| gdb_assert (pid != 0); |
| |
| it = displaced_step_inferior_states; |
| prev_next_p = &displaced_step_inferior_states; |
| while (it) |
| { |
| if (it->pid == pid) |
| { |
| *prev_next_p = it->next; |
| xfree (it); |
| return; |
| } |
| |
| prev_next_p = &it->next; |
| it = *prev_next_p; |
| } |
| } |
| |
| static void |
| infrun_inferior_exit (struct inferior *inf) |
| { |
| remove_displaced_stepping_state (inf->pid); |
| } |
| |
| /* If ON, and the architecture supports it, GDB will use displaced |
| stepping to step over breakpoints. If OFF, or if the architecture |
| doesn't support it, GDB will instead use the traditional |
| hold-and-step approach. If AUTO (which is the default), GDB will |
| decide which technique to use to step over breakpoints depending on |
| which of all-stop or non-stop mode is active --- displaced stepping |
| in non-stop mode; hold-and-step in all-stop mode. */ |
| |
| static enum auto_boolean can_use_displaced_stepping = AUTO_BOOLEAN_AUTO; |
| |
| static void |
| show_can_use_displaced_stepping (struct ui_file *file, int from_tty, |
| struct cmd_list_element *c, |
| const char *value) |
| { |
| if (can_use_displaced_stepping == AUTO_BOOLEAN_AUTO) |
| fprintf_filtered (file, |
| _("Debugger's willingness to use displaced stepping " |
| "to step over breakpoints is %s (currently %s).\n"), |
| value, non_stop ? "on" : "off"); |
| else |
| fprintf_filtered (file, |
| _("Debugger's willingness to use displaced stepping " |
| "to step over breakpoints is %s.\n"), value); |
| } |
| |
| /* Return non-zero if displaced stepping can/should be used to step |
| over breakpoints. */ |
| |
| static int |
| use_displaced_stepping (struct gdbarch *gdbarch) |
| { |
| return (((can_use_displaced_stepping == AUTO_BOOLEAN_AUTO && non_stop) |
| || can_use_displaced_stepping == AUTO_BOOLEAN_TRUE) |
| && gdbarch_displaced_step_copy_insn_p (gdbarch) |
| && !RECORD_IS_USED); |
| } |
| |
| /* Clean out any stray displaced stepping state. */ |
| static void |
| displaced_step_clear (struct displaced_step_inferior_state *displaced) |
| { |
| /* Indicate that there is no cleanup pending. */ |
| displaced->step_ptid = null_ptid; |
| |
| if (displaced->step_closure) |
| { |
| gdbarch_displaced_step_free_closure (displaced->step_gdbarch, |
| displaced->step_closure); |
| displaced->step_closure = NULL; |
| } |
| } |
| |
| static void |
| displaced_step_clear_cleanup (void *arg) |
| { |
| struct displaced_step_inferior_state *state = arg; |
| |
| displaced_step_clear (state); |
| } |
| |
| /* Dump LEN bytes at BUF in hex to FILE, followed by a newline. */ |
| void |
| displaced_step_dump_bytes (struct ui_file *file, |
| const gdb_byte *buf, |
| size_t len) |
| { |
| int i; |
| |
| for (i = 0; i < len; i++) |
| fprintf_unfiltered (file, "%02x ", buf[i]); |
| fputs_unfiltered ("\n", file); |
| } |
| |
| /* Prepare to single-step, using displaced stepping. |
| |
| Note that we cannot use displaced stepping when we have a signal to |
| deliver. If we have a signal to deliver and an instruction to step |
| over, then after the step, there will be no indication from the |
| target whether the thread entered a signal handler or ignored the |
| signal and stepped over the instruction successfully --- both cases |
| result in a simple SIGTRAP. In the first case we mustn't do a |
| fixup, and in the second case we must --- but we can't tell which. |
| Comments in the code for 'random signals' in handle_inferior_event |
| explain how we handle this case instead. |
| |
| Returns 1 if preparing was successful -- this thread is going to be |
| stepped now; or 0 if displaced stepping this thread got queued. */ |
| static int |
| displaced_step_prepare (ptid_t ptid) |
| { |
| struct cleanup *old_cleanups, *ignore_cleanups; |
| struct regcache *regcache = get_thread_regcache (ptid); |
| struct gdbarch *gdbarch = get_regcache_arch (regcache); |
| CORE_ADDR original, copy; |
| ULONGEST len; |
| struct displaced_step_closure *closure; |
| struct displaced_step_inferior_state *displaced; |
| int status; |
| |
| /* We should never reach this function if the architecture does not |
| support displaced stepping. */ |
| gdb_assert (gdbarch_displaced_step_copy_insn_p (gdbarch)); |
| |
| /* We have to displaced step one thread at a time, as we only have |
| access to a single scratch space per inferior. */ |
| |
| displaced = add_displaced_stepping_state (ptid_get_pid (ptid)); |
| |
| if (!ptid_equal (displaced->step_ptid, null_ptid)) |
| { |
| /* Already waiting for a displaced step to finish. Defer this |
| request and place in queue. */ |
| struct displaced_step_request *req, *new_req; |
| |
| if (debug_displaced) |
| fprintf_unfiltered (gdb_stdlog, |
| "displaced: defering step of %s\n", |
| target_pid_to_str (ptid)); |
| |
| new_req = xmalloc (sizeof (*new_req)); |
| new_req->ptid = ptid; |
| new_req->next = NULL; |
| |
| if (displaced->step_request_queue) |
| { |
| for (req = displaced->step_request_queue; |
| req && req->next; |
| req = req->next) |
| ; |
| req->next = new_req; |
| } |
| else |
| displaced->step_request_queue = new_req; |
| |
| return 0; |
| } |
| else |
| { |
| if (debug_displaced) |
| fprintf_unfiltered (gdb_stdlog, |
| "displaced: stepping %s now\n", |
| target_pid_to_str (ptid)); |
| } |
| |
| displaced_step_clear (displaced); |
| |
| old_cleanups = save_inferior_ptid (); |
| inferior_ptid = ptid; |
| |
| original = regcache_read_pc (regcache); |
| |
| copy = gdbarch_displaced_step_location (gdbarch); |
| len = gdbarch_max_insn_length (gdbarch); |
| |
| /* Save the original contents of the copy area. */ |
| displaced->step_saved_copy = xmalloc (len); |
| ignore_cleanups = make_cleanup (free_current_contents, |
| &displaced->step_saved_copy); |
| status = target_read_memory (copy, displaced->step_saved_copy, len); |
| if (status != 0) |
| throw_error (MEMORY_ERROR, |
| _("Error accessing memory address %s (%s) for " |
| "displaced-stepping scratch space."), |
| paddress (gdbarch, copy), safe_strerror (status)); |
| if (debug_displaced) |
| { |
| fprintf_unfiltered (gdb_stdlog, "displaced: saved %s: ", |
| paddress (gdbarch, copy)); |
| displaced_step_dump_bytes (gdb_stdlog, |
| displaced->step_saved_copy, |
| len); |
| }; |
| |
| closure = gdbarch_displaced_step_copy_insn (gdbarch, |
| original, copy, regcache); |
| |
| /* We don't support the fully-simulated case at present. */ |
| gdb_assert (closure); |
| |
| /* Save the information we need to fix things up if the step |
| succeeds. */ |
| displaced->step_ptid = ptid; |
| displaced->step_gdbarch = gdbarch; |
| displaced->step_closure = closure; |
| displaced->step_original = original; |
| displaced->step_copy = copy; |
| |
| make_cleanup (displaced_step_clear_cleanup, displaced); |
| |
| /* Resume execution at the copy. */ |
| regcache_write_pc (regcache, copy); |
| |
| discard_cleanups (ignore_cleanups); |
| |
| do_cleanups (old_cleanups); |
| |
| if (debug_displaced) |
| fprintf_unfiltered (gdb_stdlog, "displaced: displaced pc to %s\n", |
| paddress (gdbarch, copy)); |
| |
| return 1; |
| } |
| |
| static void |
| write_memory_ptid (ptid_t ptid, CORE_ADDR memaddr, |
| const gdb_byte *myaddr, int len) |
| { |
| struct cleanup *ptid_cleanup = save_inferior_ptid (); |
| |
| inferior_ptid = ptid; |
| write_memory (memaddr, myaddr, len); |
| do_cleanups (ptid_cleanup); |
| } |
| |
| /* Restore the contents of the copy area for thread PTID. */ |
| |
| static void |
| displaced_step_restore (struct displaced_step_inferior_state *displaced, |
| ptid_t ptid) |
| { |
| ULONGEST len = gdbarch_max_insn_length (displaced->step_gdbarch); |
| |
| write_memory_ptid (ptid, displaced->step_copy, |
| displaced->step_saved_copy, len); |
| if (debug_displaced) |
| fprintf_unfiltered (gdb_stdlog, "displaced: restored %s %s\n", |
| target_pid_to_str (ptid), |
| paddress (displaced->step_gdbarch, |
| displaced->step_copy)); |
| } |
| |
| static void |
| displaced_step_fixup (ptid_t event_ptid, enum gdb_signal signal) |
| { |
| struct cleanup *old_cleanups; |
| struct displaced_step_inferior_state *displaced |
| = get_displaced_stepping_state (ptid_get_pid (event_ptid)); |
| |
| /* Was any thread of this process doing a displaced step? */ |
| if (displaced == NULL) |
| return; |
| |
| /* Was this event for the pid we displaced? */ |
| if (ptid_equal (displaced->step_ptid, null_ptid) |
| || ! ptid_equal (displaced->step_ptid, event_ptid)) |
| return; |
| |
| old_cleanups = make_cleanup (displaced_step_clear_cleanup, displaced); |
| |
| displaced_step_restore (displaced, displaced->step_ptid); |
| |
| /* Did the instruction complete successfully? */ |
| if (signal == GDB_SIGNAL_TRAP) |
| { |
| /* Fix up the resulting state. */ |
| gdbarch_displaced_step_fixup (displaced->step_gdbarch, |
| displaced->step_closure, |
| displaced->step_original, |
| displaced->step_copy, |
| get_thread_regcache (displaced->step_ptid)); |
| } |
| else |
| { |
| /* Since the instruction didn't complete, all we can do is |
| relocate the PC. */ |
| struct regcache *regcache = get_thread_regcache (event_ptid); |
| CORE_ADDR pc = regcache_read_pc (regcache); |
| |
| pc = displaced->step_original + (pc - displaced->step_copy); |
| regcache_write_pc (regcache, pc); |
| } |
| |
| do_cleanups (old_cleanups); |
| |
| displaced->step_ptid = null_ptid; |
| |
| /* Are there any pending displaced stepping requests? If so, run |
| one now. Leave the state object around, since we're likely to |
| need it again soon. */ |
| while (displaced->step_request_queue) |
| { |
| struct displaced_step_request *head; |
| ptid_t ptid; |
| struct regcache *regcache; |
| struct gdbarch *gdbarch; |
| CORE_ADDR actual_pc; |
| struct address_space *aspace; |
| |
| head = displaced->step_request_queue; |
| ptid = head->ptid; |
| displaced->step_request_queue = head->next; |
| xfree (head); |
| |
| context_switch (ptid); |
| |
| regcache = get_thread_regcache (ptid); |
| actual_pc = regcache_read_pc (regcache); |
| aspace = get_regcache_aspace (regcache); |
| |
| if (breakpoint_here_p (aspace, actual_pc)) |
| { |
| if (debug_displaced) |
| fprintf_unfiltered (gdb_stdlog, |
| "displaced: stepping queued %s now\n", |
| target_pid_to_str (ptid)); |
| |
| displaced_step_prepare (ptid); |
| |
| gdbarch = get_regcache_arch (regcache); |
| |
| if (debug_displaced) |
| { |
| CORE_ADDR actual_pc = regcache_read_pc (regcache); |
| gdb_byte buf[4]; |
| |
| fprintf_unfiltered (gdb_stdlog, "displaced: run %s: ", |
| paddress (gdbarch, actual_pc)); |
| read_memory (actual_pc, buf, sizeof (buf)); |
| displaced_step_dump_bytes (gdb_stdlog, buf, sizeof (buf)); |
| } |
| |
| if (gdbarch_displaced_step_hw_singlestep (gdbarch, |
| displaced->step_closure)) |
| target_resume (ptid, 1, GDB_SIGNAL_0); |
| else |
| target_resume (ptid, 0, GDB_SIGNAL_0); |
| |
| /* Done, we're stepping a thread. */ |
| break; |
| } |
| else |
| { |
| int step; |
| struct thread_info *tp = inferior_thread (); |
| |
| /* The breakpoint we were sitting under has since been |
| removed. */ |
| tp->control.trap_expected = 0; |
| |
| /* Go back to what we were trying to do. */ |
| step = currently_stepping (tp); |
| |
| if (debug_displaced) |
| fprintf_unfiltered (gdb_stdlog, |
| "displaced: breakpoint is gone: %s, step(%d)\n", |
| target_pid_to_str (tp->ptid), step); |
| |
| target_resume (ptid, step, GDB_SIGNAL_0); |
| tp->suspend.stop_signal = GDB_SIGNAL_0; |
| |
| /* This request was discarded. See if there's any other |
| thread waiting for its turn. */ |
| } |
| } |
| } |
| |
| /* Update global variables holding ptids to hold NEW_PTID if they were |
| holding OLD_PTID. */ |
| static void |
| infrun_thread_ptid_changed (ptid_t old_ptid, ptid_t new_ptid) |
| { |
| struct displaced_step_request *it; |
| struct displaced_step_inferior_state *displaced; |
| |
| if (ptid_equal (inferior_ptid, old_ptid)) |
| inferior_ptid = new_ptid; |
| |
| if (ptid_equal (singlestep_ptid, old_ptid)) |
| singlestep_ptid = new_ptid; |
| |
| if (ptid_equal (deferred_step_ptid, old_ptid)) |
| deferred_step_ptid = new_ptid; |
| |
| for (displaced = displaced_step_inferior_states; |
| displaced; |
| displaced = displaced->next) |
| { |
| if (ptid_equal (displaced->step_ptid, old_ptid)) |
| displaced->step_ptid = new_ptid; |
| |
| for (it = displaced->step_request_queue; it; it = it->next) |
| if (ptid_equal (it->ptid, old_ptid)) |
| it->ptid = new_ptid; |
| } |
| } |
| |
| |
| /* Resuming. */ |
| |
| /* Things to clean up if we QUIT out of resume (). */ |
| static void |
| resume_cleanups (void *ignore) |
| { |
| normal_stop (); |
| } |
| |
| static const char schedlock_off[] = "off"; |
| static const char schedlock_on[] = "on"; |
| static const char schedlock_step[] = "step"; |
| static const char *const scheduler_enums[] = { |
| schedlock_off, |
| schedlock_on, |
| schedlock_step, |
| NULL |
| }; |
| static const char *scheduler_mode = schedlock_off; |
| static void |
| show_scheduler_mode (struct ui_file *file, int from_tty, |
| struct cmd_list_element *c, const char *value) |
| { |
| fprintf_filtered (file, |
| _("Mode for locking scheduler " |
| "during execution is \"%s\".\n"), |
| value); |
| } |
| |
| static void |
| set_schedlock_func (char *args, int from_tty, struct cmd_list_element *c) |
| { |
| if (!target_can_lock_scheduler) |
| { |
| scheduler_mode = schedlock_off; |
| error (_("Target '%s' cannot support this command."), target_shortname); |
| } |
| } |
| |
| /* True if execution commands resume all threads of all processes by |
| default; otherwise, resume only threads of the current inferior |
| process. */ |
| int sched_multi = 0; |
| |
| /* Try to setup for software single stepping over the specified location. |
| Return 1 if target_resume() should use hardware single step. |
| |
| GDBARCH the current gdbarch. |
| PC the location to step over. */ |
| |
| static int |
| maybe_software_singlestep (struct gdbarch *gdbarch, CORE_ADDR pc) |
| { |
| int hw_step = 1; |
| |
| if (execution_direction == EXEC_FORWARD |
| && gdbarch_software_single_step_p (gdbarch) |
| && gdbarch_software_single_step (gdbarch, get_current_frame ())) |
| { |
| hw_step = 0; |
| /* Do not pull these breakpoints until after a `wait' in |
| `wait_for_inferior'. */ |
| singlestep_breakpoints_inserted_p = 1; |
| singlestep_ptid = inferior_ptid; |
| singlestep_pc = pc; |
| } |
| return hw_step; |
| } |
| |
| /* Return a ptid representing the set of threads that we will proceed, |
| in the perspective of the user/frontend. We may actually resume |
| fewer threads at first, e.g., if a thread is stopped at a |
| breakpoint that needs stepping-off, but that should not be visible |
| to the user/frontend, and neither should the frontend/user be |
| allowed to proceed any of the threads that happen to be stopped for |
| internal run control handling, if a previous command wanted them |
| resumed. */ |
| |
| ptid_t |
| user_visible_resume_ptid (int step) |
| { |
| /* By default, resume all threads of all processes. */ |
| ptid_t resume_ptid = RESUME_ALL; |
| |
| /* Maybe resume only all threads of the current process. */ |
| if (!sched_multi && target_supports_multi_process ()) |
| { |
| resume_ptid = pid_to_ptid (ptid_get_pid (inferior_ptid)); |
| } |
| |
| /* Maybe resume a single thread after all. */ |
| if (non_stop) |
| { |
| /* With non-stop mode on, threads are always handled |
| individually. */ |
| resume_ptid = inferior_ptid; |
| } |
| else if ((scheduler_mode == schedlock_on) |
| || (scheduler_mode == schedlock_step |
| && (step || singlestep_breakpoints_inserted_p))) |
| { |
| /* User-settable 'scheduler' mode requires solo thread resume. */ |
| resume_ptid = inferior_ptid; |
| } |
| |
| return resume_ptid; |
| } |
| |
| /* Resume the inferior, but allow a QUIT. This is useful if the user |
| wants to interrupt some lengthy single-stepping operation |
| (for child processes, the SIGINT goes to the inferior, and so |
| we get a SIGINT random_signal, but for remote debugging and perhaps |
| other targets, that's not true). |
| |
| STEP nonzero if we should step (zero to continue instead). |
| SIG is the signal to give the inferior (zero for none). */ |
| void |
| resume (int step, enum gdb_signal sig) |
| { |
| int should_resume = 1; |
| struct cleanup *old_cleanups = make_cleanup (resume_cleanups, 0); |
| struct regcache *regcache = get_current_regcache (); |
| struct gdbarch *gdbarch = get_regcache_arch (regcache); |
| struct thread_info *tp = inferior_thread (); |
| CORE_ADDR pc = regcache_read_pc (regcache); |
| struct address_space *aspace = get_regcache_aspace (regcache); |
| |
| QUIT; |
| |
| if (current_inferior ()->waiting_for_vfork_done) |
| { |
| /* Don't try to single-step a vfork parent that is waiting for |
| the child to get out of the shared memory region (by exec'ing |
| or exiting). This is particularly important on software |
| single-step archs, as the child process would trip on the |
| software single step breakpoint inserted for the parent |
| process. Since the parent will not actually execute any |
| instruction until the child is out of the shared region (such |
| are vfork's semantics), it is safe to simply continue it. |
| Eventually, we'll see a TARGET_WAITKIND_VFORK_DONE event for |
| the parent, and tell it to `keep_going', which automatically |
| re-sets it stepping. */ |
| if (debug_infrun) |
| fprintf_unfiltered (gdb_stdlog, |
| "infrun: resume : clear step\n"); |
| step = 0; |
| } |
| |
| if (debug_infrun) |
| fprintf_unfiltered (gdb_stdlog, |
| "infrun: resume (step=%d, signal=%d), " |
| "trap_expected=%d, current thread [%s] at %s\n", |
| step, sig, tp->control.trap_expected, |
| target_pid_to_str (inferior_ptid), |
| paddress (gdbarch, pc)); |
| |
| /* Normally, by the time we reach `resume', the breakpoints are either |
| removed or inserted, as appropriate. The exception is if we're sitting |
| at a permanent breakpoint; we need to step over it, but permanent |
| breakpoints can't be removed. So we have to test for it here. */ |
| if (breakpoint_here_p (aspace, pc) == permanent_breakpoint_here) |
| { |
| if (gdbarch_skip_permanent_breakpoint_p (gdbarch)) |
| gdbarch_skip_permanent_breakpoint (gdbarch, regcache); |
| else |
| error (_("\ |
| The program is stopped at a permanent breakpoint, but GDB does not know\n\ |
| how to step past a permanent breakpoint on this architecture. Try using\n\ |
| a command like `return' or `jump' to continue execution.")); |
| } |
| |
| /* If enabled, step over breakpoints by executing a copy of the |
| instruction at a different address. |
| |
| We can't use displaced stepping when we have a signal to deliver; |
| the comments for displaced_step_prepare explain why. The |
| comments in the handle_inferior event for dealing with 'random |
| signals' explain what we do instead. |
| |
| We can't use displaced stepping when we are waiting for vfork_done |
| event, displaced stepping breaks the vfork child similarly as single |
| step software breakpoint. */ |
| if (use_displaced_stepping (gdbarch) |
| && (tp->control.trap_expected |
| || (step && gdbarch_software_single_step_p (gdbarch))) |
| && sig == GDB_SIGNAL_0 |
| && !current_inferior ()->waiting_for_vfork_done) |
| { |
| struct displaced_step_inferior_state *displaced; |
| |
| if (!displaced_step_prepare (inferior_ptid)) |
| { |
| /* Got placed in displaced stepping queue. Will be resumed |
| later when all the currently queued displaced stepping |
| requests finish. The thread is not executing at this point, |
| and the call to set_executing will be made later. But we |
| need to call set_running here, since from frontend point of view, |
| the thread is running. */ |
| set_running (inferior_ptid, 1); |
| discard_cleanups (old_cleanups); |
| return; |
| } |
| |
| /* Update pc to reflect the new address from which we will execute |
| instructions due to displaced stepping. */ |
| pc = regcache_read_pc (get_thread_regcache (inferior_ptid)); |
| |
| displaced = get_displaced_stepping_state (ptid_get_pid (inferior_ptid)); |
| step = gdbarch_displaced_step_hw_singlestep (gdbarch, |
| displaced->step_closure); |
| } |
| |
| /* Do we need to do it the hard way, w/temp breakpoints? */ |
| else if (step) |
| step = maybe_software_singlestep (gdbarch, pc); |
| |
| /* Currently, our software single-step implementation leads to different |
| results than hardware single-stepping in one situation: when stepping |
| into delivering a signal which has an associated signal handler, |
| hardware single-step will stop at the first instruction of the handler, |
| while software single-step will simply skip execution of the handler. |
| |
| For now, this difference in behavior is accepted since there is no |
| easy way to actually implement single-stepping into a signal handler |
| without kernel support. |
| |
| However, there is one scenario where this difference leads to follow-on |
| problems: if we're stepping off a breakpoint by removing all breakpoints |
| and then single-stepping. In this case, the software single-step |
| behavior means that even if there is a *breakpoint* in the signal |
| handler, GDB still would not stop. |
| |
| Fortunately, we can at least fix this particular issue. We detect |
| here the case where we are about to deliver a signal while software |
| single-stepping with breakpoints removed. In this situation, we |
| revert the decisions to remove all breakpoints and insert single- |
| step breakpoints, and instead we install a step-resume breakpoint |
| at the current address, deliver the signal without stepping, and |
| once we arrive back at the step-resume breakpoint, actually step |
| over the breakpoint we originally wanted to step over. */ |
| if (singlestep_breakpoints_inserted_p |
| && tp->control.trap_expected && sig != GDB_SIGNAL_0) |
| { |
| /* If we have nested signals or a pending signal is delivered |
| immediately after a handler returns, might might already have |
| a step-resume breakpoint set on the earlier handler. We cannot |
| set another step-resume breakpoint; just continue on until the |
| original breakpoint is hit. */ |
| if (tp->control.step_resume_breakpoint == NULL) |
| { |
| insert_hp_step_resume_breakpoint_at_frame (get_current_frame ()); |
| tp->step_after_step_resume_breakpoint = 1; |
| } |
| |
| remove_single_step_breakpoints (); |
| singlestep_breakpoints_inserted_p = 0; |
| |
| insert_breakpoints (); |
| tp->control.trap_expected = 0; |
| } |
| |
| if (should_resume) |
| { |
| ptid_t resume_ptid; |
| |
| /* If STEP is set, it's a request to use hardware stepping |
| facilities. But in that case, we should never |
| use singlestep breakpoint. */ |
| gdb_assert (!(singlestep_breakpoints_inserted_p && step)); |
| |
| /* Decide the set of threads to ask the target to resume. Start |
| by assuming everything will be resumed, than narrow the set |
| by applying increasingly restricting conditions. */ |
| resume_ptid = user_visible_resume_ptid (step); |
| |
| /* Maybe resume a single thread after all. */ |
| if (singlestep_breakpoints_inserted_p |
| && stepping_past_singlestep_breakpoint) |
| { |
| /* The situation here is as follows. In thread T1 we wanted to |
| single-step. Lacking hardware single-stepping we've |
| set breakpoint at the PC of the next instruction -- call it |
| P. After resuming, we've hit that breakpoint in thread T2. |
| Now we've removed original breakpoint, inserted breakpoint |
| at P+1, and try to step to advance T2 past breakpoint. |
| We need to step only T2, as if T1 is allowed to freely run, |
| it can run past P, and if other threads are allowed to run, |
| they can hit breakpoint at P+1, and nested hits of single-step |
| breakpoints is not something we'd want -- that's complicated |
| to support, and has no value. */ |
| resume_ptid = inferior_ptid; |
| } |
| else if ((step || singlestep_breakpoints_inserted_p) |
| && tp->control.trap_expected) |
| { |
| /* We're allowing a thread to run past a breakpoint it has |
| hit, by single-stepping the thread with the breakpoint |
| removed. In which case, we need to single-step only this |
| thread, and keep others stopped, as they can miss this |
| breakpoint if allowed to run. |
| |
| The current code actually removes all breakpoints when |
| doing this, not just the one being stepped over, so if we |
| let other threads run, we can actually miss any |
| breakpoint, not just the one at PC. */ |
| resume_ptid = inferior_ptid; |
| } |
| |
| if (gdbarch_cannot_step_breakpoint (gdbarch)) |
| { |
| /* Most targets can step a breakpoint instruction, thus |
| executing it normally. But if this one cannot, just |
| continue and we will hit it anyway. */ |
| if (step && breakpoint_inserted_here_p (aspace, pc)) |
| step = 0; |
| } |
| |
| if (debug_displaced |
| && use_displaced_stepping (gdbarch) |
| && tp->control.trap_expected) |
| { |
| struct regcache *resume_regcache = get_thread_regcache (resume_ptid); |
| struct gdbarch *resume_gdbarch = get_regcache_arch (resume_regcache); |
| CORE_ADDR actual_pc = regcache_read_pc (resume_regcache); |
| gdb_byte buf[4]; |
| |
| fprintf_unfiltered (gdb_stdlog, "displaced: run %s: ", |
| paddress (resume_gdbarch, actual_pc)); |
| read_memory (actual_pc, buf, sizeof (buf)); |
| displaced_step_dump_bytes (gdb_stdlog, buf, sizeof (buf)); |
| } |
| |
| /* Install inferior's terminal modes. */ |
| target_terminal_inferior (); |
| |
| /* Avoid confusing the next resume, if the next stop/resume |
| happens to apply to another thread. */ |
| tp->suspend.stop_signal = GDB_SIGNAL_0; |
| |
| /* Advise target which signals may be handled silently. If we have |
| removed breakpoints because we are stepping over one (which can |
| happen only if we are not using displaced stepping), we need to |
| receive all signals to avoid accidentally skipping a breakpoint |
| during execution of a signal handler. */ |
| if ((step || singlestep_breakpoints_inserted_p) |
| && tp->control.trap_expected |
| && !use_displaced_stepping (gdbarch)) |
| target_pass_signals (0, NULL); |
| else |
| target_pass_signals ((int) GDB_SIGNAL_LAST, signal_pass); |
| |
| target_resume (resume_ptid, step, sig); |
| } |
| |
| discard_cleanups (old_cleanups); |
| } |
| |
| /* Proceeding. */ |
| |
| /* Clear out all variables saying what to do when inferior is continued. |
| First do this, then set the ones you want, then call `proceed'. */ |
| |
| static void |
| clear_proceed_status_thread (struct thread_info *tp) |
| { |
| if (debug_infrun) |
| fprintf_unfiltered (gdb_stdlog, |
| "infrun: clear_proceed_status_thread (%s)\n", |
| target_pid_to_str (tp->ptid)); |
| |
| tp->control.trap_expected = 0; |
| tp->control.step_range_start = 0; |
| tp->control.step_range_end = 0; |
| tp->control.step_frame_id = null_frame_id; |
| tp->control.step_stack_frame_id = null_frame_id; |
| tp->control.step_over_calls = STEP_OVER_UNDEBUGGABLE; |
| tp->stop_requested = 0; |
| |
| tp->control.stop_step = 0; |
| |
| tp->control.proceed_to_finish = 0; |
| |
| /* Discard any remaining commands or status from previous stop. */ |
| bpstat_clear (&tp->control.stop_bpstat); |
| } |
| |
| static int |
| clear_proceed_status_callback (struct thread_info *tp, void *data) |
| { |
| if (is_exited (tp->ptid)) |
| return 0; |
| |
| clear_proceed_status_thread (tp); |
| return 0; |
| } |
| |
| void |
| clear_proceed_status (void) |
| { |
| if (!non_stop) |
| { |
| /* In all-stop mode, delete the per-thread status of all |
| threads, even if inferior_ptid is null_ptid, there may be |
| threads on the list. E.g., we may be launching a new |
| process, while selecting the executable. */ |
| iterate_over_threads (clear_proceed_status_callback, NULL); |
| } |
| |
| if (!ptid_equal (inferior_ptid, null_ptid)) |
| { |
| struct inferior *inferior; |
| |
| if (non_stop) |
| { |
| /* If in non-stop mode, only delete the per-thread status of |
| the current thread. */ |
| clear_proceed_status_thread (inferior_thread ()); |
| } |
| |
| inferior = current_inferior (); |
| inferior->control.stop_soon = NO_STOP_QUIETLY; |
| } |
| |
| stop_after_trap = 0; |
| |
| observer_notify_about_to_proceed (); |
| |
| if (stop_registers) |
| { |
| regcache_xfree (stop_registers); |
| stop_registers = NULL; |
| } |
| } |
| |
| /* Check the current thread against the thread that reported the most recent |
| event. If a step-over is required return TRUE and set the current thread |
| to the old thread. Otherwise return FALSE. |
| |
| This should be suitable for any targets that support threads. */ |
| |
| static int |
| prepare_to_proceed (int step) |
| { |
| ptid_t wait_ptid; |
| struct target_waitstatus wait_status; |
| int schedlock_enabled; |
| |
| /* With non-stop mode on, threads are always handled individually. */ |
| gdb_assert (! non_stop); |
| |
| /* Get the last target status returned by target_wait(). */ |
| get_last_target_status (&wait_ptid, &wait_status); |
| |
| /* Make sure we were stopped at a breakpoint. */ |
| if (wait_status.kind != TARGET_WAITKIND_STOPPED |
| || (wait_status.value.sig != GDB_SIGNAL_TRAP |
| && wait_status.value.sig != GDB_SIGNAL_ILL |
| && wait_status.value.sig != GDB_SIGNAL_SEGV |
| && wait_status.value.sig != GDB_SIGNAL_EMT)) |
| { |
| return 0; |
| } |
| |
| schedlock_enabled = (scheduler_mode == schedlock_on |
| || (scheduler_mode == schedlock_step |
| && step)); |
| |
| /* Don't switch over to WAIT_PTID if scheduler locking is on. */ |
| if (schedlock_enabled) |
| return 0; |
| |
| /* Don't switch over if we're about to resume some other process |
| other than WAIT_PTID's, and schedule-multiple is off. */ |
| if (!sched_multi |
| && ptid_get_pid (wait_ptid) != ptid_get_pid (inferior_ptid)) |
| return 0; |
| |
| /* Switched over from WAIT_PID. */ |
| if (!ptid_equal (wait_ptid, minus_one_ptid) |
| && !ptid_equal (inferior_ptid, wait_ptid)) |
| { |
| struct regcache *regcache = get_thread_regcache (wait_ptid); |
| |
| if (breakpoint_here_p (get_regcache_aspace (regcache), |
| regcache_read_pc (regcache))) |
| { |
| /* If stepping, remember current thread to switch back to. */ |
| if (step) |
| deferred_step_ptid = inferior_ptid; |
| |
| /* Switch back to WAIT_PID thread. */ |
| switch_to_thread (wait_ptid); |
| |
| if (debug_infrun) |
| fprintf_unfiltered (gdb_stdlog, |
| "infrun: prepare_to_proceed (step=%d), " |
| "switched to [%s]\n", |
| step, target_pid_to_str (inferior_ptid)); |
| |
| /* We return 1 to indicate that there is a breakpoint here, |
| so we need to step over it before continuing to avoid |
| hitting it straight away. */ |
| return 1; |
| } |
| } |
| |
| return 0; |
| } |
| |
| /* Basic routine for continuing the program in various fashions. |
| |
| ADDR is the address to resume at, or -1 for resume where stopped. |
| SIGGNAL is the signal to give it, or 0 for none, |
| or -1 for act according to how it stopped. |
| STEP is nonzero if should trap after one instruction. |
| -1 means return after that and print nothing. |
| You should probably set various step_... variables |
| before calling here, if you are stepping. |
| |
| You should call clear_proceed_status before calling proceed. */ |
| |
| void |
| proceed (CORE_ADDR addr, enum gdb_signal siggnal, int step) |
| { |
| struct regcache *regcache; |
| struct gdbarch *gdbarch; |
| struct thread_info *tp; |
| CORE_ADDR pc; |
| struct address_space *aspace; |
| int oneproc = 0; |
| |
| /* If we're stopped at a fork/vfork, follow the branch set by the |
| "set follow-fork-mode" command; otherwise, we'll just proceed |
| resuming the current thread. */ |
| if (!follow_fork ()) |
| { |
| /* The target for some reason decided not to resume. */ |
| normal_stop (); |
| if (target_can_async_p ()) |
| inferior_event_handler (INF_EXEC_COMPLETE, NULL); |
| return; |
| } |
| |
| /* We'll update this if & when we switch to a new thread. */ |
| previous_inferior_ptid = inferior_ptid; |
| |
| regcache = get_current_regcache (); |
| gdbarch = get_regcache_arch (regcache); |
| aspace = get_regcache_aspace (regcache); |
| pc = regcache_read_pc (regcache); |
| |
| if (step > 0) |
| step_start_function = find_pc_function (pc); |
| if (step < 0) |
| stop_after_trap = 1; |
| |
| if (addr == (CORE_ADDR) -1) |
| { |
| if (pc == stop_pc && breakpoint_here_p (aspace, pc) |
| && execution_direction != EXEC_REVERSE) |
| /* There is a breakpoint at the address we will resume at, |
| step one instruction before inserting breakpoints so that |
| we do not stop right away (and report a second hit at this |
| breakpoint). |
| |
| Note, we don't do this in reverse, because we won't |
| actually be executing the breakpoint insn anyway. |
| We'll be (un-)executing the previous instruction. */ |
| |
| oneproc = 1; |
| else if (gdbarch_single_step_through_delay_p (gdbarch) |
| && gdbarch_single_step_through_delay (gdbarch, |
| get_current_frame ())) |
| /* We stepped onto an instruction that needs to be stepped |
| again before re-inserting the breakpoint, do so. */ |
| oneproc = 1; |
| } |
| else |
| { |
| regcache_write_pc (regcache, addr); |
| } |
| |
| if (debug_infrun) |
| fprintf_unfiltered (gdb_stdlog, |
| "infrun: proceed (addr=%s, signal=%d, step=%d)\n", |
| paddress (gdbarch, addr), siggnal, step); |
| |
| if (non_stop) |
| /* In non-stop, each thread is handled individually. The context |
| must already be set to the right thread here. */ |
| ; |
| else |
| { |
| /* In a multi-threaded task we may select another thread and |
| then continue or step. |
| |
| But if the old thread was stopped at a breakpoint, it will |
| immediately cause another breakpoint stop without any |
| execution (i.e. it will report a breakpoint hit incorrectly). |
| So we must step over it first. |
| |
| prepare_to_proceed checks the current thread against the |
| thread that reported the most recent event. If a step-over |
| is required it returns TRUE and sets the current thread to |
| the old thread. */ |
| if (prepare_to_proceed (step)) |
| oneproc = 1; |
| } |
| |
| /* prepare_to_proceed may change the current thread. */ |
| tp = inferior_thread (); |
| |
| if (oneproc) |
| { |
| tp->control.trap_expected = 1; |
| /* If displaced stepping is enabled, we can step over the |
| breakpoint without hitting it, so leave all breakpoints |
| inserted. Otherwise we need to disable all breakpoints, step |
| one instruction, and then re-add them when that step is |
| finished. */ |
| if (!use_displaced_stepping (gdbarch)) |
| remove_breakpoints (); |
| } |
| |
| /* We can insert breakpoints if we're not trying to step over one, |
| or if we are stepping over one but we're using displaced stepping |
| to do so. */ |
| if (! tp->control.trap_expected || use_displaced_stepping (gdbarch)) |
| insert_breakpoints (); |
| |
| if (!non_stop) |
| { |
| /* Pass the last stop signal to the thread we're resuming, |
| irrespective of whether the current thread is the thread that |
| got the last event or not. This was historically GDB's |
| behaviour before keeping a stop_signal per thread. */ |
| |
| struct thread_info *last_thread; |
| ptid_t last_ptid; |
| struct target_waitstatus last_status; |
| |
| get_last_target_status (&last_ptid, &last_status); |
| if (!ptid_equal (inferior_ptid, last_ptid) |
| && !ptid_equal (last_ptid, null_ptid) |
| && !ptid_equal (last_ptid, minus_one_ptid)) |
| { |
| last_thread = find_thread_ptid (last_ptid); |
| if (last_thread) |
| { |
| tp->suspend.stop_signal = last_thread->suspend.stop_signal; |
| last_thread->suspend.stop_signal = GDB_SIGNAL_0; |
| } |
| } |
| } |
| |
| if (siggnal != GDB_SIGNAL_DEFAULT) |
| tp->suspend.stop_signal = siggnal; |
| /* If this signal should not be seen by program, |
| give it zero. Used for debugging signals. */ |
| else if (!signal_program[tp->suspend.stop_signal]) |
| tp->suspend.stop_signal = GDB_SIGNAL_0; |
| |
| annotate_starting (); |
| |
| /* Make sure that output from GDB appears before output from the |
| inferior. */ |
| gdb_flush (gdb_stdout); |
| |
| /* Refresh prev_pc value just prior to resuming. This used to be |
| done in stop_stepping, however, setting prev_pc there did not handle |
| scenarios such as inferior function calls or returning from |
| a function via the return command. In those cases, the prev_pc |
| value was not set properly for subsequent commands. The prev_pc value |
| is used to initialize the starting line number in the ecs. With an |
| invalid value, the gdb next command ends up stopping at the position |
| represented by the next line table entry past our start position. |
| On platforms that generate one line table entry per line, this |
| is not a problem. However, on the ia64, the compiler generates |
| extraneous line table entries that do not increase the line number. |
| When we issue the gdb next command on the ia64 after an inferior call |
| or a return command, we often end up a few instructions forward, still |
| within the original line we started. |
| |
| An attempt was made to refresh the prev_pc at the same time the |
| execution_control_state is initialized (for instance, just before |
| waiting for an inferior event). But this approach did not work |
| because of platforms that use ptrace, where the pc register cannot |
| be read unless the inferior is stopped. At that point, we are not |
| guaranteed the inferior is stopped and so the regcache_read_pc() call |
| can fail. Setting the prev_pc value here ensures the value is updated |
| correctly when the inferior is stopped. */ |
| tp->prev_pc = regcache_read_pc (get_current_regcache ()); |
| |
| /* Fill in with reasonable starting values. */ |
| init_thread_stepping_state (tp); |
| |
| /* Reset to normal state. */ |
| init_infwait_state (); |
| |
| /* Resume inferior. */ |
| resume (oneproc || step || bpstat_should_step (), tp->suspend.stop_signal); |
| |
| /* Wait for it to stop (if not standalone) |
| and in any case decode why it stopped, and act accordingly. */ |
| /* Do this only if we are not using the event loop, or if the target |
| does not support asynchronous execution. */ |
| if (!target_can_async_p ()) |
| { |
| wait_for_inferior (); |
| normal_stop (); |
| } |
| } |
| |
| |
| /* Start remote-debugging of a machine over a serial link. */ |
| |
| void |
| start_remote (int from_tty) |
| { |
| struct inferior *inferior; |
| |
| inferior = current_inferior (); |
| inferior->control.stop_soon = STOP_QUIETLY_REMOTE; |
| |
| /* Always go on waiting for the target, regardless of the mode. */ |
| /* FIXME: cagney/1999-09-23: At present it isn't possible to |
| indicate to wait_for_inferior that a target should timeout if |
| nothing is returned (instead of just blocking). Because of this, |
| targets expecting an immediate response need to, internally, set |
| things up so that the target_wait() is forced to eventually |
| timeout. */ |
| /* FIXME: cagney/1999-09-24: It isn't possible for target_open() to |
| differentiate to its caller what the state of the target is after |
| the initial open has been performed. Here we're assuming that |
| the target has stopped. It should be possible to eventually have |
| target_open() return to the caller an indication that the target |
| is currently running and GDB state should be set to the same as |
| for an async run. */ |
| wait_for_inferior (); |
| |
| /* Now that the inferior has stopped, do any bookkeeping like |
| loading shared libraries. We want to do this before normal_stop, |
| so that the displayed frame is up to date. */ |
| post_create_inferior (¤t_target, from_tty); |
| |
| normal_stop (); |
| } |
| |
| /* Initialize static vars when a new inferior begins. */ |
| |
| void |
| init_wait_for_inferior (void) |
| { |
| /* These are meaningless until the first time through wait_for_inferior. */ |
| |
| breakpoint_init_inferior (inf_starting); |
| |
| clear_proceed_status (); |
| |
| stepping_past_singlestep_breakpoint = 0; |
| deferred_step_ptid = null_ptid; |
| |
| target_last_wait_ptid = minus_one_ptid; |
| |
| previous_inferior_ptid = inferior_ptid; |
| init_infwait_state (); |
| |
| /* Discard any skipped inlined frames. */ |
| clear_inline_frame_state (minus_one_ptid); |
| } |
| |
| |
| /* This enum encodes possible reasons for doing a target_wait, so that |
| wfi can call target_wait in one place. (Ultimately the call will be |
| moved out of the infinite loop entirely.) */ |
| |
| enum infwait_states |
| { |
| infwait_normal_state, |
| infwait_thread_hop_state, |
| infwait_step_watch_state, |
| infwait_nonstep_watch_state |
| }; |
| |
| /* The PTID we'll do a target_wait on.*/ |
| ptid_t waiton_ptid; |
| |
| /* Current inferior wait state. */ |
| enum infwait_states infwait_state; |
| |
| /* Data to be passed around while handling an event. This data is |
| discarded between events. */ |
| struct execution_control_state |
| { |
| ptid_t ptid; |
| /* The thread that got the event, if this was a thread event; NULL |
| otherwise. */ |
| struct thread_info *event_thread; |
| |
| struct target_waitstatus ws; |
| int random_signal; |
| int stop_func_filled_in; |
| CORE_ADDR stop_func_start; |
| CORE_ADDR stop_func_end; |
| const char *stop_func_name; |
| int wait_some_more; |
| }; |
| |
| static void handle_inferior_event (struct execution_control_state *ecs); |
| |
| static void handle_step_into_function (struct gdbarch *gdbarch, |
| struct execution_control_state *ecs); |
| static void handle_step_into_function_backward (struct gdbarch *gdbarch, |
| struct execution_control_state *ecs); |
| static void check_exception_resume (struct execution_control_state *, |
| struct frame_info *); |
| |
| static void stop_stepping (struct execution_control_state *ecs); |
| static void prepare_to_wait (struct execution_control_state *ecs); |
| static void keep_going (struct execution_control_state *ecs); |
| |
| /* Callback for iterate over threads. If the thread is stopped, but |
| the user/frontend doesn't know about that yet, go through |
| normal_stop, as if the thread had just stopped now. ARG points at |
| a ptid. If PTID is MINUS_ONE_PTID, applies to all threads. If |
| ptid_is_pid(PTID) is true, applies to all threads of the process |
| pointed at by PTID. Otherwise, apply only to the thread pointed by |
| PTID. */ |
| |
| static int |
| infrun_thread_stop_requested_callback (struct thread_info *info, void *arg) |
| { |
| ptid_t ptid = * (ptid_t *) arg; |
| |
| if ((ptid_equal (info->ptid, ptid) |
| || ptid_equal (minus_one_ptid, ptid) |
| || (ptid_is_pid (ptid) |
| && ptid_get_pid (ptid) == ptid_get_pid (info->ptid))) |
| && is_running (info->ptid) |
| && !is_executing (info->ptid)) |
| { |
| struct cleanup *old_chain; |
| struct execution_control_state ecss; |
| struct execution_control_state *ecs = &ecss; |
| |
| memset (ecs, 0, sizeof (*ecs)); |
| |
| old_chain = make_cleanup_restore_current_thread (); |
| |
| /* Go through handle_inferior_event/normal_stop, so we always |
| have consistent output as if the stop event had been |
| reported. */ |
| ecs->ptid = info->ptid; |
| ecs->event_thread = find_thread_ptid (info->ptid); |
| ecs->ws.kind = TARGET_WAITKIND_STOPPED; |
| ecs->ws.value.sig = GDB_SIGNAL_0; |
| |
| handle_inferior_event (ecs); |
| |
| if (!ecs->wait_some_more) |
| { |
| struct thread_info *tp; |
| |
| normal_stop (); |
| |
| /* Finish off the continuations. */ |
| tp = inferior_thread (); |
| do_all_intermediate_continuations_thread (tp, 1); |
| do_all_continuations_thread (tp, 1); |
| } |
| |
| do_cleanups (old_chain); |
| } |
| |
| return 0; |
| } |
| |
| /* This function is attached as a "thread_stop_requested" observer. |
| Cleanup local state that assumed the PTID was to be resumed, and |
| report the stop to the frontend. */ |
| |
| static void |
| infrun_thread_stop_requested (ptid_t ptid) |
| { |
| struct displaced_step_inferior_state *displaced; |
| |
| /* PTID was requested to stop. Remove it from the displaced |
| stepping queue, so we don't try to resume it automatically. */ |
| |
| for (displaced = displaced_step_inferior_states; |
| displaced; |
| displaced = displaced->next) |
| { |
| struct displaced_step_request *it, **prev_next_p; |
| |
| it = displaced->step_request_queue; |
| prev_next_p = &displaced->step_request_queue; |
| while (it) |
| { |
| if (ptid_match (it->ptid, ptid)) |
| { |
| *prev_next_p = it->next; |
| it->next = NULL; |
| xfree (it); |
| } |
| else |
| { |
| prev_next_p = &it->next; |
| } |
| |
| it = *prev_next_p; |
| } |
| } |
| |
| iterate_over_threads (infrun_thread_stop_requested_callback, &ptid); |
| } |
| |
| static void |
| infrun_thread_thread_exit (struct thread_info *tp, int silent) |
| { |
| if (ptid_equal (target_last_wait_ptid, tp->ptid)) |
| nullify_last_target_wait_ptid (); |
| } |
| |
| /* Callback for iterate_over_threads. */ |
| |
| static int |
| delete_step_resume_breakpoint_callback (struct thread_info *info, void *data) |
| { |
| if (is_exited (info->ptid)) |
| return 0; |
| |
| delete_step_resume_breakpoint (info); |
| delete_exception_resume_breakpoint (info); |
| return 0; |
| } |
| |
| /* In all-stop, delete the step resume breakpoint of any thread that |
| had one. In non-stop, delete the step resume breakpoint of the |
| thread that just stopped. */ |
| |
| static void |
| delete_step_thread_step_resume_breakpoint (void) |
| { |
| if (!target_has_execution |
| || ptid_equal (inferior_ptid, null_ptid)) |
| /* If the inferior has exited, we have already deleted the step |
| resume breakpoints out of GDB's lists. */ |
| return; |
| |
| if (non_stop) |
| { |
| /* If in non-stop mode, only delete the step-resume or |
| longjmp-resume breakpoint of the thread that just stopped |
| stepping. */ |
| struct thread_info *tp = inferior_thread (); |
| |
| delete_step_resume_breakpoint (tp); |
| delete_exception_resume_breakpoint (tp); |
| } |
| else |
| /* In all-stop mode, delete all step-resume and longjmp-resume |
| breakpoints of any thread that had them. */ |
| iterate_over_threads (delete_step_resume_breakpoint_callback, NULL); |
| } |
| |
| /* A cleanup wrapper. */ |
| |
| static void |
| delete_step_thread_step_resume_breakpoint_cleanup (void *arg) |
| { |
| delete_step_thread_step_resume_breakpoint (); |
| } |
| |
| /* Pretty print the results of target_wait, for debugging purposes. */ |
| |
| static void |
| print_target_wait_results (ptid_t waiton_ptid, ptid_t result_ptid, |
| const struct target_waitstatus *ws) |
| { |
| char *status_string = target_waitstatus_to_string (ws); |
| struct ui_file *tmp_stream = mem_fileopen (); |
| char *text; |
| |
| /* The text is split over several lines because it was getting too long. |
| Call fprintf_unfiltered (gdb_stdlog) once so that the text is still |
| output as a unit; we want only one timestamp printed if debug_timestamp |
| is set. */ |
| |
| fprintf_unfiltered (tmp_stream, |
| "infrun: target_wait (%d", PIDGET (waiton_ptid)); |
| if (PIDGET (waiton_ptid) != -1) |
| fprintf_unfiltered (tmp_stream, |
| " [%s]", target_pid_to_str (waiton_ptid)); |
| fprintf_unfiltered (tmp_stream, ", status) =\n"); |
| fprintf_unfiltered (tmp_stream, |
| "infrun: %d [%s],\n", |
| PIDGET (result_ptid), target_pid_to_str (result_ptid)); |
| fprintf_unfiltered (tmp_stream, |
| "infrun: %s\n", |
| status_string); |
| |
| text = ui_file_xstrdup (tmp_stream, NULL); |
| |
| /* This uses %s in part to handle %'s in the text, but also to avoid |
| a gcc error: the format attribute requires a string literal. */ |
| fprintf_unfiltered (gdb_stdlog, "%s", text); |
| |
| xfree (status_string); |
| xfree (text); |
| ui_file_delete (tmp_stream); |
| } |
| |
| /* Prepare and stabilize the inferior for detaching it. E.g., |
| detaching while a thread is displaced stepping is a recipe for |
| crashing it, as nothing would readjust the PC out of the scratch |
| pad. */ |
| |
| void |
| prepare_for_detach (void) |
| { |
| struct inferior *inf = current_inferior (); |
| ptid_t pid_ptid = pid_to_ptid (inf->pid); |
| struct cleanup *old_chain_1; |
| struct displaced_step_inferior_state *displaced; |
| |
| displaced = get_displaced_stepping_state (inf->pid); |
| |
| /* Is any thread of this process displaced stepping? If not, |
| there's nothing else to do. */ |
| if (displaced == NULL || ptid_equal (displaced->step_ptid, null_ptid)) |
| return; |
| |
| if (debug_infrun) |
| fprintf_unfiltered (gdb_stdlog, |
| "displaced-stepping in-process while detaching"); |
| |
| old_chain_1 = make_cleanup_restore_integer (&inf->detaching); |
| inf->detaching = 1; |
| |
| while (!ptid_equal (displaced->step_ptid, null_ptid)) |
| { |
| struct cleanup *old_chain_2; |
| struct execution_control_state ecss; |
| struct execution_control_state *ecs; |
| |
| ecs = &ecss; |
| memset (ecs, 0, sizeof (*ecs)); |
| |
| overlay_cache_invalid = 1; |
| |
| if (deprecated_target_wait_hook) |
| ecs->ptid = deprecated_target_wait_hook (pid_ptid, &ecs->ws, 0); |
| else |
| ecs->ptid = target_wait (pid_ptid, &ecs->ws, 0); |
| |
| if (debug_infrun) |
| print_target_wait_results (pid_ptid, ecs->ptid, &ecs->ws); |
| |
| /* If an error happens while handling the event, propagate GDB's |
| knowledge of the executing state to the frontend/user running |
| state. */ |
| old_chain_2 = make_cleanup (finish_thread_state_cleanup, |
| &minus_one_ptid); |
| |
| /* Now figure out what to do with the result of the result. */ |
| handle_inferior_event (ecs); |
| |
| /* No error, don't finish the state yet. */ |
| discard_cleanups (old_chain_2); |
| |
| /* Breakpoints and watchpoints are not installed on the target |
| at this point, and signals are passed directly to the |
| inferior, so this must mean the process is gone. */ |
| if (!ecs->wait_some_more) |
| { |
| discard_cleanups (old_chain_1); |
| error (_("Program exited while detaching")); |
| } |
| } |
| |
| discard_cleanups (old_chain_1); |
| } |
| |
| /* Wait for control to return from inferior to debugger. |
| |
| If inferior gets a signal, we may decide to start it up again |
| instead of returning. That is why there is a loop in this function. |
| When this function actually returns it means the inferior |
| should be left stopped and GDB should read more commands. */ |
| |
| void |
| wait_for_inferior (void) |
| { |
| struct cleanup *old_cleanups; |
| |
| if (debug_infrun) |
| fprintf_unfiltered |
| (gdb_stdlog, "infrun: wait_for_inferior ()\n"); |
| |
| old_cleanups = |
| make_cleanup (delete_step_thread_step_resume_breakpoint_cleanup, NULL); |
| |
| while (1) |
| { |
| struct execution_control_state ecss; |
| struct execution_control_state *ecs = &ecss; |
| struct cleanup *old_chain; |
| |
| memset (ecs, 0, sizeof (*ecs)); |
| |
| overlay_cache_invalid = 1; |
| |
| if (deprecated_target_wait_hook) |
| ecs->ptid = deprecated_target_wait_hook (waiton_ptid, &ecs->ws, 0); |
| else |
| ecs->ptid = target_wait (waiton_ptid, &ecs->ws, 0); |
| |
| if (debug_infrun) |
| print_target_wait_results (waiton_ptid, ecs->ptid, &ecs->ws); |
| |
| /* If an error happens while handling the event, propagate GDB's |
| knowledge of the executing state to the frontend/user running |
| state. */ |
| old_chain = make_cleanup (finish_thread_state_cleanup, &minus_one_ptid); |
| |
| /* Now figure out what to do with the result of the result. */ |
| handle_inferior_event (ecs); |
| |
| /* No error, don't finish the state yet. */ |
| discard_cleanups (old_chain); |
| |
| if (!ecs->wait_some_more) |
| break; |
| } |
| |
| do_cleanups (old_cleanups); |
| } |
| |
| /* Asynchronous version of wait_for_inferior. It is called by the |
| event loop whenever a change of state is detected on the file |
| descriptor corresponding to the target. It can be called more than |
| once to complete a single execution command. In such cases we need |
| to keep the state in a global variable ECSS. If it is the last time |
| that this function is called for a single execution command, then |
| report to the user that the inferior has stopped, and do the |
| necessary cleanups. */ |
| |
| void |
| fetch_inferior_event (void *client_data) |
| { |
| struct execution_control_state ecss; |
| struct execution_control_state *ecs = &ecss; |
| struct cleanup *old_chain = make_cleanup (null_cleanup, NULL); |
| struct cleanup *ts_old_chain; |
| int was_sync = sync_execution; |
| int cmd_done = 0; |
| |
| memset (ecs, 0, sizeof (*ecs)); |
| |
| /* We're handling a live event, so make sure we're doing live |
| debugging. If we're looking at traceframes while the target is |
| running, we're going to need to get back to that mode after |
| handling the event. */ |
| if (non_stop) |
| { |
| make_cleanup_restore_current_traceframe (); |
| set_current_traceframe (-1); |
| } |
| |
| if (non_stop) |
| /* In non-stop mode, the user/frontend should not notice a thread |
| switch due to internal events. Make sure we reverse to the |
| user selected thread and frame after handling the event and |
| running any breakpoint commands. */ |
| make_cleanup_restore_current_thread (); |
| |
| overlay_cache_invalid = 1; |
| |
| make_cleanup_restore_integer (&execution_direction); |
| execution_direction = target_execution_direction (); |
| |
| if (deprecated_target_wait_hook) |
| ecs->ptid = |
| deprecated_target_wait_hook (waiton_ptid, &ecs->ws, TARGET_WNOHANG); |
| else |
| ecs->ptid = target_wait (waiton_ptid, &ecs->ws, TARGET_WNOHANG); |
| |
| if (debug_infrun) |
| print_target_wait_results (waiton_ptid, ecs->ptid, &ecs->ws); |
| |
| /* If an error happens while handling the event, propagate GDB's |
| knowledge of the executing state to the frontend/user running |
| state. */ |
| if (!non_stop) |
| ts_old_chain = make_cleanup (finish_thread_state_cleanup, &minus_one_ptid); |
| else |
| ts_old_chain = make_cleanup (finish_thread_state_cleanup, &ecs->ptid); |
| |
| /* Get executed before make_cleanup_restore_current_thread above to apply |
| still for the thread which has thrown the exception. */ |
| make_bpstat_clear_actions_cleanup (); |
| |
| /* Now figure out what to do with the result of the result. */ |
| handle_inferior_event (ecs); |
| |
| if (!ecs->wait_some_more) |
| { |
| struct inferior *inf = find_inferior_pid (ptid_get_pid (ecs->ptid)); |
| |
| delete_step_thread_step_resume_breakpoint (); |
| |
| /* We may not find an inferior if this was a process exit. */ |
| if (inf == NULL || inf->control.stop_soon == NO_STOP_QUIETLY) |
| normal_stop (); |
| |
| if (target_has_execution |
| && ecs->ws.kind != TARGET_WAITKIND_NO_RESUMED |
| && ecs->ws.kind != TARGET_WAITKIND_EXITED |
| && ecs->ws.kind != TARGET_WAITKIND_SIGNALLED |
| && ecs->event_thread->step_multi |
| && ecs->event_thread->control.stop_step) |
| inferior_event_handler (INF_EXEC_CONTINUE, NULL); |
| else |
| { |
| inferior_event_handler (INF_EXEC_COMPLETE, NULL); |
| cmd_done = 1; |
| } |
| } |
| |
| /* No error, don't finish the thread states yet. */ |
| discard_cleanups (ts_old_chain); |
| |
| /* Revert thread and frame. */ |
| do_cleanups (old_chain); |
| |
| /* If the inferior was in sync execution mode, and now isn't, |
| restore the prompt (a synchronous execution command has finished, |
| and we're ready for input). */ |
| if (interpreter_async && was_sync && !sync_execution) |
| display_gdb_prompt (0); |
| |
| if (cmd_done |
| && !was_sync |
| && exec_done_display_p |
| && (ptid_equal (inferior_ptid, null_ptid) |
| || !is_running (inferior_ptid))) |
| printf_unfiltered (_("completed.\n")); |
| } |
| |
| /* Record the frame and location we're currently stepping through. */ |
| void |
| set_step_info (struct frame_info *frame, struct symtab_and_line sal) |
| { |
| struct thread_info *tp = inferior_thread (); |
| |
| tp->control.step_frame_id = get_frame_id (frame); |
| tp->control.step_stack_frame_id = get_stack_frame_id (frame); |
| |
| tp->current_symtab = sal.symtab; |
| tp->current_line = sal.line; |
| } |
| |
| /* Clear context switchable stepping state. */ |
| |
| void |
| init_thread_stepping_state (struct thread_info *tss) |
| { |
| tss->stepping_over_breakpoint = 0; |
| tss->step_after_step_resume_breakpoint = 0; |
| } |
| |
| /* Return the cached copy of the last pid/waitstatus returned by |
| target_wait()/deprecated_target_wait_hook(). The data is actually |
| cached by handle_inferior_event(), which gets called immediately |
| after target_wait()/deprecated_target_wait_hook(). */ |
| |
| void |
| get_last_target_status (ptid_t *ptidp, struct target_waitstatus *status) |
| { |
| *ptidp = target_last_wait_ptid; |
| *status = target_last_waitstatus; |
| } |
| |
| void |
| nullify_last_target_wait_ptid (void) |
| { |
| target_last_wait_ptid = minus_one_ptid; |
| } |
| |
| /* Switch thread contexts. */ |
| |
| static void |
| context_switch (ptid_t ptid) |
| { |
| if (debug_infrun && !ptid_equal (ptid, inferior_ptid)) |
| { |
| fprintf_unfiltered (gdb_stdlog, "infrun: Switching context from %s ", |
| target_pid_to_str (inferior_ptid)); |
| fprintf_unfiltered (gdb_stdlog, "to %s\n", |
| target_pid_to_str (ptid)); |
| } |
| |
| switch_to_thread (ptid); |
| } |
| |
| static void |
| adjust_pc_after_break (struct execution_control_state *ecs) |
| { |
| struct regcache *regcache; |
| struct gdbarch *gdbarch; |
| struct address_space *aspace; |
| CORE_ADDR breakpoint_pc; |
| |
| /* If we've hit a breakpoint, we'll normally be stopped with SIGTRAP. If |
| we aren't, just return. |
| |
| We assume that waitkinds other than TARGET_WAITKIND_STOPPED are not |
| affected by gdbarch_decr_pc_after_break. Other waitkinds which are |
| implemented by software breakpoints should be handled through the normal |
| breakpoint layer. |
| |
| NOTE drow/2004-01-31: On some targets, breakpoints may generate |
| different signals (SIGILL or SIGEMT for instance), but it is less |
| clear where the PC is pointing afterwards. It may not match |
| gdbarch_decr_pc_after_break. I don't know any specific target that |
| generates these signals at breakpoints (the code has been in GDB since at |
| least 1992) so I can not guess how to handle them here. |
| |
| In earlier versions of GDB, a target with |
| gdbarch_have_nonsteppable_watchpoint would have the PC after hitting a |
| watchpoint affected by gdbarch_decr_pc_after_break. I haven't found any |
| target with both of these set in GDB history, and it seems unlikely to be |
| correct, so gdbarch_have_nonsteppable_watchpoint is not checked here. */ |
| |
| if (ecs->ws.kind != TARGET_WAITKIND_STOPPED) |
| return; |
| |
| if (ecs->ws.value.sig != GDB_SIGNAL_TRAP) |
| return; |
| |
| /* In reverse execution, when a breakpoint is hit, the instruction |
| under it has already been de-executed. The reported PC always |
| points at the breakpoint address, so adjusting it further would |
| be wrong. E.g., consider this case on a decr_pc_after_break == 1 |
| architecture: |
| |
| B1 0x08000000 : INSN1 |
| B2 0x08000001 : INSN2 |
| 0x08000002 : INSN3 |
| PC -> 0x08000003 : INSN4 |
| |
| Say you're stopped at 0x08000003 as above. Reverse continuing |
| from that point should hit B2 as below. Reading the PC when the |
| SIGTRAP is reported should read 0x08000001 and INSN2 should have |
| been de-executed already. |
| |
| B1 0x08000000 : INSN1 |
| B2 PC -> 0x08000001 : INSN2 |
| 0x08000002 : INSN3 |
| 0x08000003 : INSN4 |
| |
| We can't apply the same logic as for forward execution, because |
| we would wrongly adjust the PC to 0x08000000, since there's a |
| breakpoint at PC - 1. We'd then report a hit on B1, although |
| INSN1 hadn't been de-executed yet. Doing nothing is the correct |
| behaviour. */ |
| if (execution_direction == EXEC_REVERSE) |
| return; |
| |
| /* If this target does not decrement the PC after breakpoints, then |
| we have nothing to do. */ |
| regcache = get_thread_regcache (ecs->ptid); |
| gdbarch = get_regcache_arch (regcache); |
| if (gdbarch_decr_pc_after_break (gdbarch) == 0) |
| return; |
| |
| aspace = get_regcache_aspace (regcache); |
| |
| /* Find the location where (if we've hit a breakpoint) the |
| breakpoint would be. */ |
| breakpoint_pc = regcache_read_pc (regcache) |
| - gdbarch_decr_pc_after_break (gdbarch); |
| |
| /* Check whether there actually is a software breakpoint inserted at |
| that location. |
| |
| If in non-stop mode, a race condition is possible where we've |
| removed a breakpoint, but stop events for that breakpoint were |
| already queued and arrive later. To suppress those spurious |
| SIGTRAPs, we keep a list of such breakpoint locations for a bit, |
| and retire them after a number of stop events are reported. */ |
| if (software_breakpoint_inserted_here_p (aspace, breakpoint_pc) |
| || (non_stop && moribund_breakpoint_here_p (aspace, breakpoint_pc))) |
| { |
| struct cleanup *old_cleanups = NULL; |
| |
| if (RECORD_IS_USED) |
| old_cleanups = record_gdb_operation_disable_set (); |
| |
| /* When using hardware single-step, a SIGTRAP is reported for both |
| a completed single-step and a software breakpoint. Need to |
| differentiate between the two, as the latter needs adjusting |
| but the former does not. |
| |
| The SIGTRAP can be due to a completed hardware single-step only if |
| - we didn't insert software single-step breakpoints |
| - the thread to be examined is still the current thread |
| - this thread is currently being stepped |
| |
| If any of these events did not occur, we must have stopped due |
| to hitting a software breakpoint, and have to back up to the |
| breakpoint address. |
| |
| As a special case, we could have hardware single-stepped a |
| software breakpoint. In this case (prev_pc == breakpoint_pc), |
| we also need to back up to the breakpoint address. */ |
| |
| if (singlestep_breakpoints_inserted_p |
| || !ptid_equal (ecs->ptid, inferior_ptid) |
| || !currently_stepping (ecs->event_thread) |
| || ecs->event_thread->prev_pc == breakpoint_pc) |
| regcache_write_pc (regcache, breakpoint_pc); |
| |
| if (RECORD_IS_USED) |
| do_cleanups (old_cleanups); |
| } |
| } |
| |
| void |
| init_infwait_state (void) |
| { |
| waiton_ptid = pid_to_ptid (-1); |
| infwait_state = infwait_normal_state; |
| } |
| |
| void |
| error_is_running (void) |
| { |
| error (_("Cannot execute this command while " |
| "the selected thread is running.")); |
| } |
| |
| void |
| ensure_not_running (void) |
| { |
| if (is_running (inferior_ptid)) |
| error_is_running (); |
| } |
| |
| static int |
| stepped_in_from (struct frame_info *frame, struct frame_id step_frame_id) |
| { |
| for (frame = get_prev_frame (frame); |
| frame != NULL; |
| frame = get_prev_frame (frame)) |
| { |
| if (frame_id_eq (get_frame_id (frame), step_frame_id)) |
| return 1; |
| if (get_frame_type (frame) != INLINE_FRAME) |
| break; |
| } |
| |
| return 0; |
| } |
| |
| /* Auxiliary function that handles syscall entry/return events. |
| It returns 1 if the inferior should keep going (and GDB |
| should ignore the event), or 0 if the event deserves to be |
| processed. */ |
| |
| static int |
| handle_syscall_event (struct execution_control_state *ecs) |
| { |
| struct regcache *regcache; |
| struct gdbarch *gdbarch; |
| int syscall_number; |
| |
| if (!ptid_equal (ecs->ptid, inferior_ptid)) |
| context_switch (ecs->ptid); |
| |
| regcache = get_thread_regcache (ecs->ptid); |
| gdbarch = get_regcache_arch (regcache); |
| syscall_number = ecs->ws.value.syscall_number; |
| stop_pc = regcache_read_pc (regcache); |
| |
| if (catch_syscall_enabled () > 0 |
| && catching_syscall_number (syscall_number) > 0) |
| { |
| if (debug_infrun) |
| fprintf_unfiltered (gdb_stdlog, "infrun: syscall number = '%d'\n", |
| syscall_number); |
| |
| ecs->event_thread->control.stop_bpstat |
| = bpstat_stop_status (get_regcache_aspace (regcache), |
| stop_pc, ecs->ptid, &ecs->ws); |
| ecs->random_signal |
| = !bpstat_explains_signal (ecs->event_thread->control.stop_bpstat); |
| |
| if (!ecs->random_signal) |
| { |
| /* Catchpoint hit. */ |
| ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_TRAP; |
| return 0; |
| } |
| } |
| |
| /* If no catchpoint triggered for this, then keep going. */ |
| ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0; |
| keep_going (ecs); |
| return 1; |
| } |
| |
| /* Clear the supplied execution_control_state's stop_func_* fields. */ |
| |
| static void |
| clear_stop_func (struct execution_control_state *ecs) |
| { |
| ecs->stop_func_filled_in = 0; |
| ecs->stop_func_start = 0; |
| ecs->stop_func_end = 0; |
| ecs->stop_func_name = NULL; |
| } |
| |
| /* Lazily fill in the execution_control_state's stop_func_* fields. */ |
| |
| static void |
| fill_in_stop_func (struct gdbarch *gdbarch, |
| struct execution_control_state *ecs) |
| { |
| if (!ecs->stop_func_filled_in) |
| { |
| /* Don't care about return value; stop_func_start and stop_func_name |
| will both be 0 if it doesn't work. */ |
| find_pc_partial_function (stop_pc, &ecs->stop_func_name, |
| &ecs->stop_func_start, &ecs->stop_func_end); |
| ecs->stop_func_start |
| += gdbarch_deprecated_function_start_offset (gdbarch); |
| |
| ecs->stop_func_filled_in = 1; |
| } |
| } |
| |
| /* Given an execution control state that has been freshly filled in |
| by an event from the inferior, figure out what it means and take |
| appropriate action. */ |
| |
| static void |
| handle_inferior_event (struct execution_control_state *ecs) |
| { |
| struct frame_info *frame; |
| struct gdbarch *gdbarch; |
| int stopped_by_watchpoint; |
| int stepped_after_stopped_by_watchpoint = 0; |
| struct symtab_and_line stop_pc_sal; |
| enum stop_kind stop_soon; |
| |
| if (ecs->ws.kind == TARGET_WAITKIND_IGNORE) |
| { |
| /* We had an event in the inferior, but we are not interested in |
| handling it at this level. The lower layers have already |
| done what needs to be done, if anything. |
| |
| One of the possible circumstances for this is when the |
| inferior produces output for the console. The inferior has |
| not stopped, and we are ignoring the event. Another possible |
| circumstance is any event which the lower level knows will be |
| reported multiple times without an intervening resume. */ |
| if (debug_infrun) |
| fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_IGNORE\n"); |
| prepare_to_wait (ecs); |
| return; |
| } |
| |
| if (ecs->ws.kind == TARGET_WAITKIND_NO_RESUMED |
| && target_can_async_p () && !sync_execution) |
| { |
| /* There were no unwaited-for children left in the target, but, |
| we're not synchronously waiting for events either. Just |
| ignore. Otherwise, if we were running a synchronous |
| execution command, we need to cancel it and give the user |
| back the terminal. */ |
| if (debug_infrun) |
| fprintf_unfiltered (gdb_stdlog, |
| "infrun: TARGET_WAITKIND_NO_RESUMED (ignoring)\n"); |
| prepare_to_wait (ecs); |
| return; |
| } |
| |
| if (ecs->ws.kind != TARGET_WAITKIND_EXITED |
| && ecs->ws.kind != TARGET_WAITKIND_SIGNALLED |
| && ecs->ws.kind != TARGET_WAITKIND_NO_RESUMED) |
| { |
| struct inferior *inf = find_inferior_pid (ptid_get_pid (ecs->ptid)); |
| |
| gdb_assert (inf); |
| stop_soon = inf->control.stop_soon; |
| } |
| else |
| stop_soon = NO_STOP_QUIETLY; |
| |
| /* Cache the last pid/waitstatus. */ |
| target_last_wait_ptid = ecs->ptid; |
| target_last_waitstatus = ecs->ws; |
| |
| /* Always clear state belonging to the previous time we stopped. */ |
| stop_stack_dummy = STOP_NONE; |
| |
| if (ecs->ws.kind == TARGET_WAITKIND_NO_RESUMED) |
| { |
| /* No unwaited-for children left. IOW, all resumed children |
| have exited. */ |
| if (debug_infrun) |
| fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_NO_RESUMED\n"); |
| |
| stop_print_frame = 0; |
| stop_stepping (ecs); |
| return; |
| } |
| |
| if (ecs->ws.kind != TARGET_WAITKIND_EXITED |
| && ecs->ws.kind != TARGET_WAITKIND_SIGNALLED |
| && !ptid_equal (ecs->ptid, minus_one_ptid)) |
| { |
| ecs->event_thread = find_thread_ptid (ecs->ptid); |
| /* If it's a new thread, add it to the thread database. */ |
| if (ecs->event_thread == NULL) |
| ecs->event_thread = add_thread (ecs->ptid); |
| } |
| |
| /* Dependent on valid ECS->EVENT_THREAD. */ |
| adjust_pc_after_break (ecs); |
| |
| /* Dependent on the current PC value modified by adjust_pc_after_break. */ |
| reinit_frame_cache (); |
| |
| breakpoint_retire_moribund (); |
| |
| /* First, distinguish signals caused by the debugger from signals |
| that have to do with the program's own actions. Note that |
| breakpoint insns may cause SIGTRAP or SIGILL or SIGEMT, depending |
| on the operating system version. Here we detect when a SIGILL or |
| SIGEMT is really a breakpoint and change it to SIGTRAP. We do |
| something similar for SIGSEGV, since a SIGSEGV will be generated |
| when we're trying to execute a breakpoint instruction on a |
| non-executable stack. This happens for call dummy breakpoints |
| for architectures like SPARC that place call dummies on the |
| stack. */ |
| if (ecs->ws.kind == TARGET_WAITKIND_STOPPED |
| && (ecs->ws.value.sig == GDB_SIGNAL_ILL |
| || ecs->ws.value.sig == GDB_SIGNAL_SEGV |
| || ecs->ws.value.sig == GDB_SIGNAL_EMT)) |
| { |
| struct regcache *regcache = get_thread_regcache (ecs->ptid); |
| |
| if (breakpoint_inserted_here_p (get_regcache_aspace (regcache), |
| regcache_read_pc (regcache))) |
| { |
| if (debug_infrun) |
| fprintf_unfiltered (gdb_stdlog, |
| "infrun: Treating signal as SIGTRAP\n"); |
| ecs->ws.value.sig = GDB_SIGNAL_TRAP; |
| } |
| } |
| |
| /* Mark the non-executing threads accordingly. In all-stop, all |
| threads of all processes are stopped when we get any event |
| reported. In non-stop mode, only the event thread stops. If |
| we're handling a process exit in non-stop mode, there's nothing |
| to do, as threads of the dead process are gone, and threads of |
| any other process were left running. */ |
| if (!non_stop) |
| set_executing (minus_one_ptid, 0); |
| else if (ecs->ws.kind != TARGET_WAITKIND_SIGNALLED |
| && ecs->ws.kind != TARGET_WAITKIND_EXITED) |
| set_executing (ecs->ptid, 0); |
| |
| switch (infwait_state) |
| { |
| case infwait_thread_hop_state: |
| if (debug_infrun) |
| fprintf_unfiltered (gdb_stdlog, "infrun: infwait_thread_hop_state\n"); |
| break; |
| |
| case infwait_normal_state: |
| if (debug_infrun) |
| fprintf_unfiltered (gdb_stdlog, "infrun: infwait_normal_state\n"); |
| break; |
| |
| case infwait_step_watch_state: |
| if (debug_infrun) |
| fprintf_unfiltered (gdb_stdlog, |
| "infrun: infwait_step_watch_state\n"); |
| |
| stepped_after_stopped_by_watchpoint = 1; |
| break; |
| |
| case infwait_nonstep_watch_state: |
| if (debug_infrun) |
| fprintf_unfiltered (gdb_stdlog, |
| "infrun: infwait_nonstep_watch_state\n"); |
| insert_breakpoints (); |
| |
| /* FIXME-maybe: is this cleaner than setting a flag? Does it |
| handle things like signals arriving and other things happening |
| in combination correctly? */ |
| stepped_after_stopped_by_watchpoint = 1; |
| break; |
| |
| default: |
| internal_error (__FILE__, __LINE__, _("bad switch")); |
| } |
| |
| infwait_state = infwait_normal_state; |
| waiton_ptid = pid_to_ptid (-1); |
| |
| switch (ecs->ws.kind) |
| { |
| case TARGET_WAITKIND_LOADED: |
| if (debug_infrun) |
| fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_LOADED\n"); |
| /* Ignore gracefully during startup of the inferior, as it might |
| be the shell which has just loaded some objects, otherwise |
| add the symbols for the newly loaded objects. Also ignore at |
| the beginning of an attach or remote session; we will query |
| the full list of libraries once the connection is |
| established. */ |
| if (stop_soon == NO_STOP_QUIETLY) |
| { |
| struct regcache *regcache; |
| |
| if (!ptid_equal (ecs->ptid, inferior_ptid)) |
| context_switch (ecs->ptid); |
| regcache = get_thread_regcache (ecs->ptid); |
| |
| handle_solib_event (); |
| |
| ecs->event_thread->control.stop_bpstat |
| = bpstat_stop_status (get_regcache_aspace (regcache), |
| stop_pc, ecs->ptid, &ecs->ws); |
| ecs->random_signal |
| = !bpstat_explains_signal (ecs->event_thread->control.stop_bpstat); |
| |
| if (!ecs->random_signal) |
| { |
| /* A catchpoint triggered. */ |
| ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_TRAP; |
| goto process_event_stop_test; |
| } |
| |
| /* If requested, stop when the dynamic linker notifies |
| gdb of events. This allows the user to get control |
| and place breakpoints in initializer routines for |
| dynamically loaded objects (among other things). */ |
| ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0; |
| if (stop_on_solib_events) |
| { |
| /* Make sure we print "Stopped due to solib-event" in |
| normal_stop. */ |
| stop_print_frame = 1; |
| |
| stop_stepping (ecs); |
| return; |
| } |
| } |
| |
| /* If we are skipping through a shell, or through shared library |
| loading that we aren't interested in, resume the program. If |
| we're running the program normally, also resume. But stop if |
| we're attaching or setting up a remote connection. */ |
| if (stop_soon == STOP_QUIETLY || stop_soon == NO_STOP_QUIETLY) |
| { |
| if (!ptid_equal (ecs->ptid, inferior_ptid)) |
| context_switch (ecs->ptid); |
| |
| /* Loading of shared libraries might have changed breakpoint |
| addresses. Make sure new breakpoints are inserted. */ |
| if (stop_soon == NO_STOP_QUIETLY |
| && !breakpoints_always_inserted_mode ()) |
| insert_breakpoints (); |
| resume (0, GDB_SIGNAL_0); |
| prepare_to_wait (ecs); |
| return; |
| } |
| |
| break; |
| |
| case TARGET_WAITKIND_SPURIOUS: |
| if (debug_infrun) |
| fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_SPURIOUS\n"); |
| if (!ptid_equal (ecs->ptid, inferior_ptid) |
| && !ptid_equal (ecs->ptid, minus_one_ptid)) |
| context_switch (ecs->ptid); |
| resume (0, GDB_SIGNAL_0); |
| prepare_to_wait (ecs); |
| return; |
| |
| case TARGET_WAITKIND_EXITED: |
| if (debug_infrun) |
| fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_EXITED\n"); |
| inferior_ptid = ecs->ptid; |
| set_current_inferior (find_inferior_pid (ptid_get_pid (ecs->ptid))); |
| set_current_program_space (current_inferior ()->pspace); |
| handle_vfork_child_exec_or_exit (0); |
| target_terminal_ours (); /* Must do this before mourn anyway. */ |
| print_exited_reason (ecs->ws.value.integer); |
| |
| /* Record the exit code in the convenience variable $_exitcode, so |
| that the user can inspect this again later. */ |
| set_internalvar_integer (lookup_internalvar ("_exitcode"), |
| (LONGEST) ecs->ws.value.integer); |
| |
| /* Also record this in the inferior itself. */ |
| current_inferior ()->has_exit_code = 1; |
| current_inferior ()->exit_code = (LONGEST) ecs->ws.value.integer; |
| |
| gdb_flush (gdb_stdout); |
| target_mourn_inferior (); |
| singlestep_breakpoints_inserted_p = 0; |
| cancel_single_step_breakpoints (); |
| stop_print_frame = 0; |
| stop_stepping (ecs); |
| return; |
| |
| case TARGET_WAITKIND_SIGNALLED: |
| if (debug_infrun) |
| fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_SIGNALLED\n"); |
| inferior_ptid = ecs->ptid; |
| set_current_inferior (find_inferior_pid (ptid_get_pid (ecs->ptid))); |
| set_current_program_space (current_inferior ()->pspace); |
| handle_vfork_child_exec_or_exit (0); |
| stop_print_frame = 0; |
| target_terminal_ours (); /* Must do this before mourn anyway. */ |
| |
| /* Note: By definition of TARGET_WAITKIND_SIGNALLED, we shouldn't |
| reach here unless the inferior is dead. However, for years |
| target_kill() was called here, which hints that fatal signals aren't |
| really fatal on some systems. If that's true, then some changes |
| may be needed. */ |
| target_mourn_inferior (); |
| |
| print_signal_exited_reason (ecs->ws.value.sig); |
| singlestep_breakpoints_inserted_p = 0; |
| cancel_single_step_breakpoints (); |
| stop_stepping (ecs); |
| return; |
| |
| /* The following are the only cases in which we keep going; |
| the above cases end in a continue or goto. */ |
| case TARGET_WAITKIND_FORKED: |
| case TARGET_WAITKIND_VFORKED: |
| if (debug_infrun) |
| fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_FORKED\n"); |
| |
| /* Check whether the inferior is displaced stepping. */ |
| { |
| struct regcache *regcache = get_thread_regcache (ecs->ptid); |
| struct gdbarch *gdbarch = get_regcache_arch (regcache); |
| struct displaced_step_inferior_state *displaced |
| = get_displaced_stepping_state (ptid_get_pid (ecs->ptid)); |
| |
| /* If checking displaced stepping is supported, and thread |
| ecs->ptid is displaced stepping. */ |
| if (displaced && ptid_equal (displaced->step_ptid, ecs->ptid)) |
| { |
| struct inferior *parent_inf |
| = find_inferior_pid (ptid_get_pid (ecs->ptid)); |
| struct regcache *child_regcache; |
| CORE_ADDR parent_pc; |
| |
| /* GDB has got TARGET_WAITKIND_FORKED or TARGET_WAITKIND_VFORKED, |
| indicating that the displaced stepping of syscall instruction |
| has been done. Perform cleanup for parent process here. Note |
| that this operation also cleans up the child process for vfork, |
| because their pages are shared. */ |
| displaced_step_fixup (ecs->ptid, GDB_SIGNAL_TRAP); |
| |
| if (ecs->ws.kind == TARGET_WAITKIND_FORKED) |
| { |
| /* Restore scratch pad for child process. */ |
| displaced_step_restore (displaced, ecs->ws.value.related_pid); |
| } |
| |
| /* Since the vfork/fork syscall instruction was executed in the scratchpad, |
| the child's PC is also within the scratchpad. Set the child's PC |
| to the parent's PC value, which has already been fixed up. |
| FIXME: we use the parent's aspace here, although we're touching |
| the child, because the child hasn't been added to the inferior |
| list yet at this point. */ |
| |
| child_regcache |
| = get_thread_arch_aspace_regcache (ecs->ws.value.related_pid, |
| gdbarch, |
| parent_inf->aspace); |
| /* Read PC value of parent process. */ |
| parent_pc = regcache_read_pc (regcache); |
| |
| if (debug_displaced) |
| fprintf_unfiltered (gdb_stdlog, |
| "displaced: write child pc from %s to %s\n", |
| paddress (gdbarch, |
| regcache_read_pc (child_regcache)), |
| paddress (gdbarch, parent_pc)); |
| |
| regcache_write_pc (child_regcache, parent_pc); |
| } |
| } |
| |
| if (!ptid_equal (ecs->ptid, inferior_ptid)) |
| context_switch (ecs->ptid); |
| |
| /* Immediately detach breakpoints from the child before there's |
| any chance of letting the user delete breakpoints from the |
| breakpoint lists. If we don't do this early, it's easy to |
| leave left over traps in the child, vis: "break foo; catch |
| fork; c; <fork>; del; c; <child calls foo>". We only follow |
| the fork on the last `continue', and by that time the |
| breakpoint at "foo" is long gone from the breakpoint table. |
| If we vforked, then we don't need to unpatch here, since both |
| parent and child are sharing the same memory pages; we'll |
| need to unpatch at follow/detach time instead to be certain |
| that new breakpoints added between catchpoint hit time and |
| vfork follow are detached. */ |
| if (ecs->ws.kind != TARGET_WAITKIND_VFORKED) |
| { |
| int child_pid = ptid_get_pid (ecs->ws.value.related_pid); |
| |
| /* This won't actually modify the breakpoint list, but will |
| physically remove the breakpoints from the child. */ |
| detach_breakpoints (child_pid); |
| } |
| |
| if (singlestep_breakpoints_inserted_p) |
| { |
| /* Pull the single step breakpoints out of the target. */ |
| remove_single_step_breakpoints (); |
| singlestep_breakpoints_inserted_p = 0; |
| } |
| |
| /* In case the event is caught by a catchpoint, remember that |
| the event is to be followed at the next resume of the thread, |
| and not immediately. */ |
| ecs->event_thread->pending_follow = ecs->ws; |
| |
| stop_pc = regcache_read_pc (get_thread_regcache (ecs->ptid)); |
| |
| ecs->event_thread->control.stop_bpstat |
| = bpstat_stop_status (get_regcache_aspace (get_current_regcache ()), |
| stop_pc, ecs->ptid, &ecs->ws); |
| |
| /* Note that we're interested in knowing the bpstat actually |
| causes a stop, not just if it may explain the signal. |
| Software watchpoints, for example, always appear in the |
| bpstat. */ |
| ecs->random_signal |
| = !bpstat_causes_stop (ecs->event_thread->control.stop_bpstat); |
| |
| /* If no catchpoint triggered for this, then keep going. */ |
| if (ecs->random_signal) |
| { |
| ptid_t parent; |
| ptid_t child; |
| int should_resume; |
| int follow_child |
| = (follow_fork_mode_string == follow_fork_mode_child); |
| |
| ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0; |
| |
| should_resume = follow_fork (); |
| |
| parent = ecs->ptid; |
| child = ecs->ws.value.related_pid; |
| |
| /* In non-stop mode, also resume the other branch. */ |
| if (non_stop && !detach_fork) |
| { |
| if (follow_child) |
| switch_to_thread (parent); |
| else |
| switch_to_thread (child); |
| |
| ecs->event_thread = inferior_thread (); |
| ecs->ptid = inferior_ptid; |
| keep_going (ecs); |
| } |
| |
| if (follow_child) |
| switch_to_thread (child); |
| else |
| switch_to_thread (parent); |
| |
| ecs->event_thread = inferior_thread (); |
| ecs->ptid = inferior_ptid; |
| |
| if (should_resume) |
| keep_going (ecs); |
| else |
| stop_stepping (ecs); |
| return; |
| } |
| ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_TRAP; |
| goto process_event_stop_test; |
| |
| case TARGET_WAITKIND_VFORK_DONE: |
| /* Done with the shared memory region. Re-insert breakpoints in |
| the parent, and keep going. */ |
| |
| if (debug_infrun) |
| fprintf_unfiltered (gdb_stdlog, |
| "infrun: TARGET_WAITKIND_VFORK_DONE\n"); |
| |
| if (!ptid_equal (ecs->ptid, inferior_ptid)) |
| context_switch (ecs->ptid); |
| |
| current_inferior ()->waiting_for_vfork_done = 0; |
| current_inferior ()->pspace->breakpoints_not_allowed = 0; |
| /* This also takes care of reinserting breakpoints in the |
| previously locked inferior. */ |
| keep_going (ecs); |
| return; |
| |
| case TARGET_WAITKIND_EXECD: |
| if (debug_infrun) |
| fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_EXECD\n"); |
| |
| if (!ptid_equal (ecs->ptid, inferior_ptid)) |
| context_switch (ecs->ptid); |
| |
| singlestep_breakpoints_inserted_p = 0; |
| cancel_single_step_breakpoints (); |
| |
| stop_pc = regcache_read_pc (get_thread_regcache (ecs->ptid)); |
| |
| /* Do whatever is necessary to the parent branch of the vfork. */ |
| handle_vfork_child_exec_or_exit (1); |
| |
| /* This causes the eventpoints and symbol table to be reset. |
| Must do this now, before trying to determine whether to |
| stop. */ |
| follow_exec (inferior_ptid, ecs->ws.value.execd_pathname); |
| |
| ecs->event_thread->control.stop_bpstat |
| = bpstat_stop_status (get_regcache_aspace (get_current_regcache ()), |
| stop_pc, ecs->ptid, &ecs->ws); |
| ecs->random_signal |
| = !bpstat_explains_signal (ecs->event_thread->control.stop_bpstat); |
| |
| /* Note that this may be referenced from inside |
| bpstat_stop_status above, through inferior_has_execd. */ |
| xfree (ecs->ws.value.execd_pathname); |
| ecs->ws.value.execd_pathname = NULL; |
| |
| /* If no catchpoint triggered for this, then keep going. */ |
| if (ecs->random_signal) |
| { |
| ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0; |
| keep_going (ecs); |
| return; |
| } |
| ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_TRAP; |
| goto process_event_stop_test; |
| |
| /* Be careful not to try to gather much state about a thread |
| that's in a syscall. It's frequently a losing proposition. */ |
| case TARGET_WAITKIND_SYSCALL_ENTRY: |
| if (debug_infrun) |
| fprintf_unfiltered (gdb_stdlog, |
| "infrun: TARGET_WAITKIND_SYSCALL_ENTRY\n"); |
| /* Getting the current syscall number. */ |
| if (handle_syscall_event (ecs) != 0) |
| return; |
| goto process_event_stop_test; |
| |
| /* Before examining the threads further, step this thread to |
| get it entirely out of the syscall. (We get notice of the |
| event when the thread is just on the verge of exiting a |
| syscall. Stepping one instruction seems to get it back |
| into user code.) */ |
| case TARGET_WAITKIND_SYSCALL_RETURN: |
| if (debug_infrun) |
| fprintf_unfiltered (gdb_stdlog, |
| "infrun: TARGET_WAITKIND_SYSCALL_RETURN\n"); |
| if (handle_syscall_event (ecs) != 0) |
| return; |
| goto process_event_stop_test; |
| |
| case TARGET_WAITKIND_STOPPED: |
| if (debug_infrun) |
| fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_STOPPED\n"); |
| ecs->event_thread->suspend.stop_signal = ecs->ws.value.sig; |
| break; |
| |
| case TARGET_WAITKIND_NO_HISTORY: |
| if (debug_infrun) |
| fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_NO_HISTORY\n"); |
| /* Reverse execution: target ran out of history info. */ |
| stop_pc = regcache_read_pc (get_thread_regcache (ecs->ptid)); |
| print_no_history_reason (); |
| stop_stepping (ecs); |
| return; |
| } |
| |
| if (ecs->ws.kind == TARGET_WAITKIND_STOPPED) |
| { |
| /* Do we need to clean up the state of a thread that has |
| completed a displaced single-step? (Doing so usually affects |
| the PC, so do it here, before we set stop_pc.) */ |
| displaced_step_fixup (ecs->ptid, |
| ecs->event_thread->suspend.stop_signal); |
| |
| /* If we either finished a single-step or hit a breakpoint, but |
| the user wanted this thread to be stopped, pretend we got a |
| SIG0 (generic unsignaled stop). */ |
| |
| if (ecs->event_thread->stop_requested |
| && ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP) |
| ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0; |
| } |
| |
| stop_pc = regcache_read_pc (get_thread_regcache (ecs->ptid)); |
| |
| if (debug_infrun) |
| { |
| struct regcache *regcache = get_thread_regcache (ecs->ptid); |
| struct gdbarch *gdbarch = get_regcache_arch (regcache); |
| struct cleanup *old_chain = save_inferior_ptid (); |
| |
| inferior_ptid = ecs->ptid; |
| |
| fprintf_unfiltered (gdb_stdlog, "infrun: stop_pc = %s\n", |
| paddress (gdbarch, stop_pc)); |
| if (target_stopped_by_watchpoint ()) |
| { |
| CORE_ADDR addr; |
| |
| fprintf_unfiltered (gdb_stdlog, "infrun: stopped by watchpoint\n"); |
| |
| if (target_stopped_data_address (¤t_target, &addr)) |
| fprintf_unfiltered (gdb_stdlog, |
| "infrun: stopped data address = %s\n", |
| paddress (gdbarch, addr)); |
| else |
| fprintf_unfiltered (gdb_stdlog, |
| "infrun: (no data address available)\n"); |
| } |
| |
| do_cleanups (old_chain); |
| } |
| |
| if (stepping_past_singlestep_breakpoint) |
| { |
| gdb_assert (singlestep_breakpoints_inserted_p); |
| gdb_assert (ptid_equal (singlestep_ptid, ecs->ptid)); |
| gdb_assert (!ptid_equal (singlestep_ptid, saved_singlestep_ptid)); |
| |
| stepping_past_singlestep_breakpoint = 0; |
| |
| /* We've either finished single-stepping past the single-step |
| breakpoint, or stopped for some other reason. It would be nice if |
| we could tell, but we can't reliably. */ |
| if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP) |
| { |
| if (debug_infrun) |
| fprintf_unfiltered (gdb_stdlog, |
| "infrun: stepping_past_" |
| "singlestep_breakpoint\n"); |
| /* Pull the single step breakpoints out of the target. */ |
| if (!ptid_equal (ecs->ptid, inferior_ptid)) |
| context_switch (ecs->ptid); |
| remove_single_step_breakpoints (); |
| singlestep_breakpoints_inserted_p = 0; |
| |
| ecs->random_signal = 0; |
| ecs->event_thread->control.trap_expected = 0; |
| |
| context_switch (saved_singlestep_ptid); |
| if (deprecated_context_hook) |
| deprecated_context_hook (pid_to_thread_id (ecs->ptid)); |
| |
| resume (1, GDB_SIGNAL_0); |
| prepare_to_wait (ecs); |
| return; |
| } |
| } |
| |
| if (!ptid_equal (deferred_step_ptid, null_ptid)) |
| { |
| /* In non-stop mode, there's never a deferred_step_ptid set. */ |
| gdb_assert (!non_stop); |
| |
| /* If we stopped for some other reason than single-stepping, ignore |
| the fact that we were supposed to switch back. */ |
| if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP) |
| { |
| if (debug_infrun) |
| fprintf_unfiltered (gdb_stdlog, |
| "infrun: handling deferred step\n"); |
| |
| /* Pull the single step breakpoints out of the target. */ |
| if (singlestep_breakpoints_inserted_p) |
| { |
| if (!ptid_equal (ecs->ptid, inferior_ptid)) |
| context_switch (ecs->ptid); |
| remove_single_step_breakpoints (); |
| singlestep_breakpoints_inserted_p = 0; |
| } |
| |
| ecs->event_thread->control.trap_expected = 0; |
| |
| context_switch (deferred_step_ptid); |
| deferred_step_ptid = null_ptid; |
| /* Suppress spurious "Switching to ..." message. */ |
| previous_inferior_ptid = inferior_ptid; |
| |
| resume (1, GDB_SIGNAL_0); |
| prepare_to_wait (ecs); |
| return; |
| } |
| |
| deferred_step_ptid = null_ptid; |
| } |
| |
| /* See if a thread hit a thread-specific breakpoint that was meant for |
| another thread. If so, then step that thread past the breakpoint, |
| and continue it. */ |
| |
| if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP) |
| { |
| int thread_hop_needed = 0; |
| struct address_space *aspace = |
| get_regcache_aspace (get_thread_regcache (ecs->ptid)); |
| |
| /* Check if a regular breakpoint has been hit before checking |
| for a potential single step breakpoint. Otherwise, GDB will |
| not see this breakpoint hit when stepping onto breakpoints. */ |
| if (regular_breakpoint_inserted_here_p (aspace, stop_pc)) |
| { |
| ecs->random_signal = 0; |
| if (!breakpoint_thread_match (aspace, stop_pc, ecs->ptid)) |
| thread_hop_needed = 1; |
| } |
| else if (singlestep_breakpoints_inserted_p) |
| { |
| /* We have not context switched yet, so this should be true |
| no matter which thread hit the singlestep breakpoint. */ |
| gdb_assert (ptid_equal (inferior_ptid, singlestep_ptid)); |
| if (debug_infrun) |
| fprintf_unfiltered (gdb_stdlog, "infrun: software single step " |
| "trap for %s\n", |
| target_pid_to_str (ecs->ptid)); |
| |
| ecs->random_signal = 0; |
| /* The call to in_thread_list is necessary because PTIDs sometimes |
| change when we go from single-threaded to multi-threaded. If |
| the singlestep_ptid is still in the list, assume that it is |
| really different from ecs->ptid. */ |
| if (!ptid_equal (singlestep_ptid, ecs->ptid) |
| && in_thread_list (singlestep_ptid)) |
| { |
| /* If the PC of the thread we were trying to single-step |
| has changed, discard this event (which we were going |
| to ignore anyway), and pretend we saw that thread |
| trap. This prevents us continuously moving the |
| single-step breakpoint forward, one instruction at a |
| time. If the PC has changed, then the thread we were |
| trying to single-step has trapped or been signalled, |
| but the event has not been reported to GDB yet. |
| |
| There might be some cases where this loses signal |
| information, if a signal has arrived at exactly the |
| same time that the PC changed, but this is the best |
| we can do with the information available. Perhaps we |
| should arrange to report all events for all threads |
| when they stop, or to re-poll the remote looking for |
| this particular thread (i.e. temporarily enable |
| schedlock). */ |
| |
| CORE_ADDR new_singlestep_pc |
| = regcache_read_pc (get_thread_regcache (singlestep_ptid)); |
| |
| if (new_singlestep_pc != singlestep_pc) |
| { |
| enum gdb_signal stop_signal; |
| |
| if (debug_infrun) |
| fprintf_unfiltered (gdb_stdlog, "infrun: unexpected thread," |
| " but expected thread advanced also\n"); |
| |
| /* The current context still belongs to |
| singlestep_ptid. Don't swap here, since that's |
| the context we want to use. Just fudge our |
| state and continue. */ |
| stop_signal = ecs->event_thread->suspend.stop_signal; |
| ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0; |
| ecs->ptid = singlestep_ptid; |
| ecs->event_thread = find_thread_ptid (ecs->ptid); |
| ecs->event_thread->suspend.stop_signal = stop_signal; |
| stop_pc = new_singlestep_pc; |
| } |
| else |
| { |
| if (debug_infrun) |
| fprintf_unfiltered (gdb_stdlog, |
| "infrun: unexpected thread\n"); |
| |
| thread_hop_needed = 1; |
| stepping_past_singlestep_breakpoint = 1; |
| saved_singlestep_ptid = singlestep_ptid; |
| } |
| } |
| } |
| |
| if (thread_hop_needed) |
| { |
| struct regcache *thread_regcache; |
| int remove_status = 0; |
| |
| if (debug_infrun) |
| fprintf_unfiltered (gdb_stdlog, "infrun: thread_hop_needed\n"); |
| |
| /* Switch context before touching inferior memory, the |
| previous thread may have exited. */ |
| if (!ptid_equal (inferior_ptid, ecs->ptid)) |
| context_switch (ecs->ptid); |
| |
| /* Saw a breakpoint, but it was hit by the wrong thread. |
| Just continue. */ |
| |
| if (singlestep_breakpoints_inserted_p) |
| { |
| /* Pull the single step breakpoints out of the target. */ |
| remove_single_step_breakpoints (); |
| singlestep_breakpoints_inserted_p = 0; |
| } |
| |
| /* If the arch can displace step, don't remove the |
| breakpoints. */ |
| thread_regcache = get_thread_regcache (ecs->ptid); |
| if (!use_displaced_stepping (get_regcache_arch (thread_regcache))) |
| remove_status = remove_breakpoints (); |
| |
| /* Did we fail to remove breakpoints? If so, try |
| to set the PC past the bp. (There's at least |
| one situation in which we can fail to remove |
| the bp's: On HP-UX's that use ttrace, we can't |
| change the address space of a vforking child |
| process until the child exits (well, okay, not |
| then either :-) or execs. */ |
| if (remove_status != 0) |
| error (_("Cannot step over breakpoint hit in wrong thread")); |
| else |
| { /* Single step */ |
| if (!non_stop) |
| { |
| /* Only need to require the next event from this |
| thread in all-stop mode. */ |
| waiton_ptid = ecs->ptid; |
| infwait_state = infwait_thread_hop_state; |
| } |
| |
| ecs->event_thread->stepping_over_breakpoint = 1; |
| keep_going (ecs); |
| return; |
| } |
| } |
| else if (singlestep_breakpoints_inserted_p) |
| { |
| ecs->random_signal = 0; |
| } |
| } |
| else |
| ecs->random_signal = 1; |
| |
| /* See if something interesting happened to the non-current thread. If |
| so, then switch to that thread. */ |
| if (!ptid_equal (ecs->ptid, inferior_ptid)) |
| { |
| if (debug_infrun) |
| fprintf_unfiltered (gdb_stdlog, "infrun: context switch\n"); |
| |
| context_switch (ecs->ptid); |
| |
| if (deprecated_context_hook) |
| deprecated_context_hook (pid_to_thread_id (ecs->ptid)); |
| } |
| |
| /* At this point, get hold of the now-current thread's frame. */ |
| frame = get_current_frame (); |
| gdbarch = get_frame_arch (frame); |
| |
| if (singlestep_breakpoints_inserted_p) |
| { |
| /* Pull the single step breakpoints out of the target. */ |
| remove_single_step_breakpoints (); |
| singlestep_breakpoints_inserted_p = 0; |
| } |
| |
| if (stepped_after_stopped_by_watchpoint) |
| stopped_by_watchpoint = 0; |
| else |
| stopped_by_watchpoint = watchpoints_triggered (&ecs->ws); |
| |
| /* If necessary, step over this watchpoint. We'll be back to display |
| it in a moment. */ |
| if (stopped_by_watchpoint |
| && (target_have_steppable_watchpoint |
| || gdbarch_have_nonsteppable_watchpoint (gdbarch))) |
| { |
| /* At this point, we are stopped at an instruction which has |
| attempted to write to a piece of memory under control of |
| a watchpoint. The instruction hasn't actually executed |
| yet. If we were to evaluate the watchpoint expression |
| now, we would get the old value, and therefore no change |
| would seem to have occurred. |
| |
| In order to make watchpoints work `right', we really need |
| to complete the memory write, and then evaluate the |
| watchpoint expression. We do this by single-stepping the |
| target. |
| |
| It may not be necessary to disable the watchpoint to stop over |
| it. For example, the PA can (with some kernel cooperation) |
| single step over a watchpoint without disabling the watchpoint. |
| |
| It is far more common to need to disable a watchpoint to step |
| the inferior over it. If we have non-steppable watchpoints, |
| we must disable the current watchpoint; it's simplest to |
| disable all watchpoints and breakpoints. */ |
| int hw_step = 1; |
| |
| if (!target_have_steppable_watchpoint) |
| { |
| remove_breakpoints (); |
| /* See comment in resume why we need to stop bypassing signals |
| while breakpoints have been removed. */ |
| target_pass_signals (0, NULL); |
| } |
| /* Single step */ |
| hw_step = maybe_software_singlestep (gdbarch, stop_pc); |
| target_resume (ecs->ptid, hw_step, GDB_SIGNAL_0); |
| waiton_ptid = ecs->ptid; |
| if (target_have_steppable_watchpoint) |
| infwait_state = infwait_step_watch_state; |
| else |
| infwait_state = infwait_nonstep_watch_state; |
| prepare_to_wait (ecs); |
| return; |
| } |
| |
| clear_stop_func (ecs); |
| ecs->event_thread->stepping_over_breakpoint = 0; |
| bpstat_clear (&ecs->event_thread->control.stop_bpstat); |
| ecs->event_thread->control.stop_step = 0; |
| stop_print_frame = 1; |
| ecs->random_signal = 0; |
| stopped_by_random_signal = 0; |
| |
| /* Hide inlined functions starting here, unless we just performed stepi or |
| nexti. After stepi and nexti, always show the innermost frame (not any |
| inline function call sites). */ |
| if (ecs->event_thread->control.step_range_end != 1) |
| { |
| struct address_space *aspace = |
| get_regcache_aspace (get_thread_regcache (ecs->ptid)); |
| |
| /* skip_inline_frames is expensive, so we avoid it if we can |
| determine that the address is one where functions cannot have |
| been inlined. This improves performance with inferiors that |
| load a lot of shared libraries, because the solib event |
| breakpoint is defined as the address of a function (i.e. not |
| inline). Note that we have to check the previous PC as well |
| as the current one to catch cases when we have just |
| single-stepped off a breakpoint prior to reinstating it. |
| Note that we're assuming that the code we single-step to is |
| not inline, but that's not definitive: there's nothing |
| preventing the event breakpoint function from containing |
| inlined code, and the single-step ending up there. If the |
| user had set a breakpoint on that inlined code, the missing |
| skip_inline_frames call would break things. Fortunately |
| that's an extremely unlikely scenario. */ |
| if (!pc_at_non_inline_function (aspace, stop_pc, &ecs->ws) |
| && !(ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP |
| && ecs->event_thread->control.trap_expected |
| && pc_at_non_inline_function (aspace, |
| ecs->event_thread->prev_pc, |
| &ecs->ws))) |
| { |
| skip_inline_frames (ecs->ptid); |
| |
| /* Re-fetch current thread's frame in case that invalidated |
| the frame cache. */ |
| frame = get_current_frame (); |
| gdbarch = get_frame_arch (frame); |
| } |
| } |
| |
| if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP |
| && ecs->event_thread->control.trap_expected |
| && gdbarch_single_step_through_delay_p (gdbarch) |
| && currently_stepping (ecs->event_thread)) |
| { |
| /* We're trying to step off a breakpoint. Turns out that we're |
| also on an instruction that needs to be stepped multiple |
| times before it's been fully executing. E.g., architectures |
| with a delay slot. It needs to be stepped twice, once for |
| the instruction and once for the delay slot. */ |
| int step_through_delay |
| = gdbarch_single_step_through_delay (gdbarch, frame); |
| |
| if (debug_infrun && step_through_delay) |
| fprintf_unfiltered (gdb_stdlog, "infrun: step through delay\n"); |
| if (ecs->event_thread->control.step_range_end == 0 |
| && step_through_delay) |
| { |
| /* The user issued a continue when stopped at a breakpoint. |
| Set up for another trap and get out of here. */ |
| ecs->event_thread->stepping_over_breakpoint = 1; |
| keep_going (ecs); |
| return; |
| } |
| else if (step_through_delay) |
| { |
| /* The user issued a step when stopped at a breakpoint. |
| Maybe we should stop, maybe we should not - the delay |
| slot *might* correspond to a line of source. In any |
| case, don't decide that here, just set |
| ecs->stepping_over_breakpoint, making sure we |
| single-step again before breakpoints are re-inserted. */ |
| ecs->event_thread->stepping_over_breakpoint = 1; |
| } |
| } |
| |
| /* Look at the cause of the stop, and decide what to do. |
| The alternatives are: |
| 1) stop_stepping and return; to really stop and return to the debugger, |
| 2) keep_going and return to start up again |
| (set ecs->event_thread->stepping_over_breakpoint to 1 to single step once) |
| 3) set ecs->random_signal to 1, and the decision between 1 and 2 |
| will be made according to the signal handling tables. */ |
| |
| if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP |
| || stop_soon == STOP_QUIETLY || stop_soon == STOP_QUIETLY_NO_SIGSTOP |
| || stop_soon == STOP_QUIETLY_REMOTE) |
| { |
| if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP |
| && stop_after_trap) |
| { |
| if (debug_infrun) |
| fprintf_unfiltered (gdb_stdlog, "infrun: stopped\n"); |
| stop_print_frame = 0; |
| stop_stepping (ecs); |
| return; |
| } |
| |
| /* This is originated from start_remote(), start_inferior() and |
| shared libraries hook functions. */ |
| if (stop_soon == STOP_QUIETLY || stop_soon == STOP_QUIETLY_REMOTE) |
| { |
| if (debug_infrun) |
| fprintf_unfiltered (gdb_stdlog, "infrun: quietly stopped\n"); |
| stop_stepping (ecs); |
| return; |
| } |
| |
| /* This originates from attach_command(). We need to overwrite |
| the stop_signal here, because some kernels don't ignore a |
| SIGSTOP in a subsequent ptrace(PTRACE_CONT,SIGSTOP) call. |
| See more comments in inferior.h. On the other hand, if we |
| get a non-SIGSTOP, report it to the user - assume the backend |
| will handle the SIGSTOP if it should show up later. |
| |
| Also consider that the attach is complete when we see a |
| SIGTRAP. Some systems (e.g. Windows), and stubs supporting |
| target extended-remote report it instead of a SIGSTOP |
| (e.g. gdbserver). We already rely on SIGTRAP being our |
| signal, so this is no exception. |
| |
| Also consider that the attach is complete when we see a |
| GDB_SIGNAL_0. In non-stop mode, GDB will explicitly tell |
| the target to stop all threads of the inferior, in case the |
| low level attach operation doesn't stop them implicitly. If |
| they weren't stopped implicitly, then the stub will report a |
| GDB_SIGNAL_0, meaning: stopped for no particular reason |
| other than GDB's request. */ |
| if (stop_soon == STOP_QUIETLY_NO_SIGSTOP |
| && (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_STOP |
| || ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP |
| || ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_0)) |
| { |
| stop_stepping (ecs); |
| ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0; |
| return; |
| } |
| |
| /* See if there is a breakpoint/watchpoint/catchpoint/etc. that |
| handles this event. */ |
| ecs->event_thread->control.stop_bpstat |
| = bpstat_stop_status (get_regcache_aspace (get_current_regcache ()), |
| stop_pc, ecs->ptid, &ecs->ws); |
| |
| /* Following in case break condition called a |
| function. */ |
| stop_print_frame = 1; |
| |
| /* This is where we handle "moribund" watchpoints. Unlike |
| software breakpoints traps, hardware watchpoint traps are |
| always distinguishable from random traps. If no high-level |
| watchpoint is associated with the reported stop data address |
| anymore, then the bpstat does not explain the signal --- |
| simply make sure to ignore it if `stopped_by_watchpoint' is |
| set. */ |
| |
| if (debug_infrun |
| && ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP |
| && !bpstat_explains_signal (ecs->event_thread->control.stop_bpstat) |
| && stopped_by_watchpoint) |
| fprintf_unfiltered (gdb_stdlog, |
| "infrun: no user watchpoint explains " |
| "watchpoint SIGTRAP, ignoring\n"); |
| |
| /* NOTE: cagney/2003-03-29: These two checks for a random signal |
| at one stage in the past included checks for an inferior |
| function call's call dummy's return breakpoint. The original |
| comment, that went with the test, read: |
| |
| ``End of a stack dummy. Some systems (e.g. Sony news) give |
| another signal besides SIGTRAP, so check here as well as |
| above.'' |
| |
| If someone ever tries to get call dummys on a |
| non-executable stack to work (where the target would stop |
| with something like a SIGSEGV), then those tests might need |
| to be re-instated. Given, however, that the tests were only |
| enabled when momentary breakpoints were not being used, I |
| suspect that it won't be the case. |
| |
| NOTE: kettenis/2004-02-05: Indeed such checks don't seem to |
| be necessary for call dummies on a non-executable stack on |
| SPARC. */ |
| |
| if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP) |
| ecs->random_signal |
| = !(bpstat_explains_signal (ecs->event_thread->control.stop_bpstat) |
| || stopped_by_watchpoint |
| || ecs->event_thread->control.trap_expected |
| || (ecs->event_thread->control.step_range_end |
| && (ecs->event_thread->control.step_resume_breakpoint |
| == NULL))); |
| else |
| { |
| ecs->random_signal = !bpstat_explains_signal |
| (ecs->event_thread->control.stop_bpstat); |
| if (!ecs->random_signal) |
| ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_TRAP; |
| } |
| } |
| |
| /* When we reach this point, we've pretty much decided |
| that the reason for stopping must've been a random |
| (unexpected) signal. */ |
| |
| else |
| ecs->random_signal = 1; |
| |
| process_event_stop_test: |
| |
| /* Re-fetch current thread's frame in case we did a |
| "goto process_event_stop_test" above. */ |
| frame = get_current_frame (); |
| gdbarch = get_frame_arch (frame); |
| |
| /* For the program's own signals, act according to |
| the signal handling tables. */ |
| |
| if (ecs->random_signal) |
| { |
| /* Signal not for debugging purposes. */ |
| int printed = 0; |
| struct inferior *inf = find_inferior_pid (ptid_get_pid (ecs->ptid)); |
| |
| if (debug_infrun) |
| fprintf_unfiltered (gdb_stdlog, "infrun: random signal %d\n", |
| ecs->event_thread->suspend.stop_signal); |
| |
| stopped_by_random_signal = 1; |
| |
| if (signal_print[ecs->event_thread->suspend.stop_signal]) |
| { |
| printed = 1; |
| target_terminal_ours_for_output (); |
| print_signal_received_reason |
| (ecs->event_thread->suspend.stop_signal); |
| } |
| /* Always stop on signals if we're either just gaining control |
| of the program, or the user explicitly requested this thread |
| to remain stopped. */ |
| if (stop_soon != NO_STOP_QUIETLY |
| || ecs->event_thread->stop_requested |
| || (!inf->detaching |
| && signal_stop_state (ecs->event_thread->suspend.stop_signal))) |
| { |
| stop_stepping (ecs); |
| return; |
| } |
| /* If not going to stop, give terminal back |
| if we took it away. */ |
| else if (printed) |
| target_terminal_inferior (); |
| |
| /* Clear the signal if it should not be passed. */ |
| if (signal_program[ecs->event_thread->suspend.stop_signal] == 0) |
| ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0; |
| |
| if (ecs->event_thread->prev_pc == stop_pc |
| && ecs->event_thread->control.trap_expected |
| && ecs->event_thread->control.step_resume_breakpoint == NULL) |
| { |
| /* We were just starting a new sequence, attempting to |
| single-step off of a breakpoint and expecting a SIGTRAP. |
| Instead this signal arrives. This signal will take us out |
| of the stepping range so GDB needs to remember to, when |
| the signal handler returns, resume stepping off that |
| breakpoint. */ |
| /* To simplify things, "continue" is forced to use the same |
| code paths as single-step - set a breakpoint at the |
| signal return address and then, once hit, step off that |
| breakpoint. */ |
| if (debug_infrun) |
| fprintf_unfiltered (gdb_stdlog, |
| "infrun: signal arrived while stepping over " |
| "breakpoint\n"); |
| |
| insert_hp_step_resume_breakpoint_at_frame (frame); |
| ecs->event_thread->step_after_step_resume_breakpoint = 1; |
| /* Reset trap_expected to ensure breakpoints are re-inserted. */ |
| ecs->event_thread->control.trap_expected = 0; |
| keep_going (ecs); |
| return; |
| } |
| |
| if (ecs->event_thread->control.step_range_end != 0 |
| && ecs->event_thread->suspend.stop_signal != GDB_SIGNAL_0 |
| && (ecs->event_thread->control.step_range_start <= stop_pc |
| && stop_pc < ecs->event_thread->control.step_range_end) |
| && frame_id_eq (get_stack_frame_id (frame), |
| ecs->event_thread->control.step_stack_frame_id) |
| && ecs->event_thread->control.step_resume_breakpoint == NULL) |
| { |
| /* The inferior is about to take a signal that will take it |
| out of the single step range. Set a breakpoint at the |
| current PC (which is presumably where the signal handler |
| will eventually return) and then allow the inferior to |
| run free. |
| |
| Note that this is only needed for a signal delivered |
| while in the single-step range. Nested signals aren't a |
| problem as they eventually all return. */ |
| if (debug_infrun) |
| fprintf_unfiltered (gdb_stdlog, |
| "infrun: signal may take us out of " |
| "single-step range\n"); |
| |
| insert_hp_step_resume_breakpoint_at_frame (frame); |
| /* Reset trap_expected to ensure breakpoints are re-inserted. */ |
| ecs->event_thread->control.trap_expected = 0; |
| keep_going (ecs); |
| return; |
| } |
| |
| /* Note: step_resume_breakpoint may be non-NULL. This occures |
| when either there's a nested signal, or when there's a |
| pending signal enabled just as the signal handler returns |
| (leaving the inferior at the step-resume-breakpoint without |
| actually executing it). Either way continue until the |
| breakpoint is really hit. */ |
| } |
| else |
| { |
| /* Handle cases caused by hitting a breakpoint. */ |
| |
| CORE_ADDR jmp_buf_pc; |
| struct bpstat_what what; |
| |
| what = bpstat_what (ecs->event_thread->control.stop_bpstat); |
| |
| if (what.call_dummy) |
| { |
| stop_stack_dummy = what.call_dummy; |
| } |
| |
| /* If we hit an internal event that triggers symbol changes, the |
| current frame will be invalidated within bpstat_what (e.g., |
| if we hit an internal solib event). Re-fetch it. */ |
| frame = get_current_frame (); |
| gdbarch = get_frame_arch (frame); |
| |
| switch (what.main_action) |
| { |
| case BPSTAT_WHAT_SET_LONGJMP_RESUME: |
| /* If we hit the breakpoint at longjmp while stepping, we |
| install a momentary breakpoint at the target of the |
| jmp_buf. */ |
| |
| if (debug_infrun) |
| fprintf_unfiltered (gdb_stdlog, |
| "infrun: BPSTAT_WHAT_SET_LONGJMP_RESUME\n"); |
| |
| ecs->event_thread->stepping_over_breakpoint = 1; |
| |
| if (what.is_longjmp) |
| { |
| struct value *arg_value; |
| |
| /* If we set the longjmp breakpoint via a SystemTap |
| probe, then use it to extract the arguments. The |
| destination PC is the third argument to the |
| probe. */ |
| arg_value = probe_safe_evaluate_at_pc (frame, 2); |
| if (arg_value) |
| jmp_buf_pc = value_as_address (arg_value); |
| else if (!gdbarch_get_longjmp_target_p (gdbarch) |
| || !gdbarch_get_longjmp_target (gdbarch, |
| frame, &jmp_buf_pc)) |
| { |
| if (debug_infrun) |
| fprintf_unfiltered (gdb_stdlog, |
| "infrun: BPSTAT_WHAT_SET_LONGJMP_RESUME " |
| "(!gdbarch_get_longjmp_target)\n"); |
| keep_going (ecs); |
| return; |
| } |
| |
| /* Insert a breakpoint at resume address. */ |
| insert_longjmp_resume_breakpoint (gdbarch, jmp_buf_pc); |
| } |
| else |
| check_exception_resume (ecs, frame); |
| keep_going (ecs); |
| return; |
| |
| case BPSTAT_WHAT_CLEAR_LONGJMP_RESUME: |
| { |
| struct frame_info *init_frame; |
| |
| /* There are several cases to consider. |
| |
| 1. The initiating frame no longer exists. In this case |
| we must stop, because the exception or longjmp has gone |
| too far. |
| |
| 2. The initiating frame exists, and is the same as the |
| current frame. We stop, because the exception or |
| longjmp has been caught. |
| |
| 3. The initiating frame exists and is different from |
| the current frame. This means the exception or longjmp |
| has been caught beneath the initiating frame, so keep |
| going. |
| |
| 4. longjmp breakpoint has been placed just to protect |
| against stale dummy frames and user is not interested |
| in stopping around longjmps. */ |
| |
| if (debug_infrun) |
| fprintf_unfiltered (gdb_stdlog, |
| "infrun: BPSTAT_WHAT_CLEAR_LONGJMP_RESUME\n"); |
| |
| gdb_assert (ecs->event_thread->control.exception_resume_breakpoint |
| != NULL); |
| delete_exception_resume_breakpoint (ecs->event_thread); |
| |
| if (what.is_longjmp) |
| { |
| check_longjmp_breakpoint_for_call_dummy (ecs->event_thread->num); |
| |
| if (!frame_id_p (ecs->event_thread->initiating_frame)) |
| { |
| /* Case 4. */ |
| keep_going (ecs); |
| return; |
| } |
| } |
| |
| init_frame = frame_find_by_id (ecs->event_thread->initiating_frame); |
| |
| if (init_frame) |
| { |
| struct frame_id current_id |
| = get_frame_id (get_current_frame ()); |
| if (frame_id_eq (current_id, |
| ecs->event_thread->initiating_frame)) |
| { |
| /* Case 2. Fall through. */ |
| } |
| else |
| { |
| /* Case 3. */ |
| keep_going (ecs); |
| return; |
| } |
| } |
| |
| /* For Cases 1 and 2, remove the step-resume breakpoint, |
| if it exists. */ |
| delete_step_resume_breakpoint (ecs->event_thread); |
| |
| ecs->event_thread->control.stop_step = 1; |
| print_end_stepping_range_reason (); |
| stop_stepping (ecs); |
| } |
| return; |
| |
| case BPSTAT_WHAT_SINGLE: |
| if (debug_infrun) |
| fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_SINGLE\n"); |
| ecs->event_thread->stepping_over_breakpoint = 1; |
| /* Still need to check other stuff, at least the case where |
| we are stepping and step out of the right range. */ |
| break; |
| |
| case BPSTAT_WHAT_STEP_RESUME: |
| if (debug_infrun) |
| fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_STEP_RESUME\n"); |
| |
| delete_step_resume_breakpoint (ecs->event_thread); |
| if (ecs->event_thread->control.proceed_to_finish |
| && execution_direction == EXEC_REVERSE) |
| { |
| struct thread_info *tp = ecs->event_thread; |
| |
| /* We are finishing a function in reverse, and just hit |
| the step-resume breakpoint at the start address of |
| the function, and we're almost there -- just need to |
| back up by one more single-step, which should take us |
| back to the function call. */ |
| tp->control.step_range_start = tp->control.step_range_end = 1; |
| keep_going (ecs); |
| return; |
| } |
| fill_in_stop_func (gdbarch, ecs); |
| if (stop_pc == ecs->stop_func_start |
| && execution_direction == EXEC_REVERSE) |
| { |
| /* We are stepping over a function call in reverse, and |
| just hit the step-resume breakpoint at the start |
| address of the function. Go back to single-stepping, |
| which should take us back to the function call. */ |
| ecs->event_thread->stepping_over_breakpoint = 1; |
| keep_going (ecs); |
| return; |
| } |
| break; |
| |
| case BPSTAT_WHAT_STOP_NOISY: |
| if (debug_infrun) |
| fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_STOP_NOISY\n"); |
| stop_print_frame = 1; |
| |
| /* We are about to nuke the step_resume_breakpointt via the |
| cleanup chain, so no need to worry about it here. */ |
| |
| stop_stepping (ecs); |
| return; |
| |
| case BPSTAT_WHAT_STOP_SILENT: |
| if (debug_infrun) |
| fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_STOP_SILENT\n"); |
| stop_print_frame = 0; |
| |
| /* We are about to nuke the step_resume_breakpoin via the |
| cleanup chain, so no need to worry about it here. */ |
| |
| stop_stepping (ecs); |
| return; |
| |
| case BPSTAT_WHAT_HP_STEP_RESUME: |
| if (debug_infrun) |
| fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_HP_STEP_RESUME\n"); |
| |
| delete_step_resume_breakpoint (ecs->event_thread); |
| if (ecs->event_thread->step_after_step_resume_breakpoint) |
| { |
| /* Back when the step-resume breakpoint was inserted, we |
| were trying to single-step off a breakpoint. Go back |
| to doing that. */ |
| ecs->event_thread->step_after_step_resume_breakpoint = 0; |
| ecs->event_thread->stepping_over_breakpoint = 1; |
| keep_going (ecs); |
| return; |
| } |
| break; |
| |
| case BPSTAT_WHAT_KEEP_CHECKING: |
| break; |
| } |
| } |
| |
| /* We come here if we hit a breakpoint but should not |
| stop for it. Possibly we also were stepping |
| and should stop for that. So fall through and |
| test for stepping. But, if not stepping, |
| do not stop. */ |
| |
| /* In all-stop mode, if we're currently stepping but have stopped in |
| some other thread, we need to switch back to the stepped thread. */ |
| if (!non_stop) |
| { |
| struct thread_info *tp; |
| |
| tp = iterate_over_threads (currently_stepping_or_nexting_callback, |
| ecs->event_thread); |
| if (tp) |
| { |
| /* However, if the current thread is blocked on some internal |
| breakpoint, and we simply need to step over that breakpoint |
| to get it going again, do that first. */ |
| if ((ecs->event_thread->control.trap_expected |
| && ecs->event_thread->suspend.stop_signal != GDB_SIGNAL_TRAP) |
| || ecs->event_thread->stepping_over_breakpoint) |
| { |
| keep_going (ecs); |
| return; |
| } |
| |
| /* If the stepping thread exited, then don't try to switch |
| back and resume it, which could fail in several different |
| ways depending on the target. Instead, just keep going. |
| |
| We can find a stepping dead thread in the thread list in |
| two cases: |
| |
| - The target supports thread exit events, and when the |
| target tries to delete the thread from the thread list, |
| inferior_ptid pointed at the exiting thread. In such |
| case, calling delete_thread does not really remove the |
| thread from the list; instead, the thread is left listed, |
| with 'exited' state. |
| |
| - The target's debug interface does not support thread |
| exit events, and so we have no idea whatsoever if the |
| previously stepping thread is still alive. For that |
| reason, we need to synchronously query the target |
| now. */ |
| if (is_exited (tp->ptid) |
| || !target_thread_alive (tp->ptid)) |
| { |
| if (debug_infrun) |
| fprintf_unfiltered (gdb_stdlog, |
| "infrun: not switching back to " |
| "stepped thread, it has vanished\n"); |
| |
| delete_thread (tp->ptid); |
| keep_going (ecs); |
| return; |
| } |
| |
| /* Otherwise, we no longer expect a trap in the current thread. |
| Clear the trap_expected flag before switching back -- this is |
| what keep_going would do as well, if we called it. */ |
| ecs->event_thread->control.trap_expected = 0; |
| |
| if (debug_infrun) |
| fprintf_unfiltered (gdb_stdlog, |
| "infrun: switching back to stepped thread\n"); |
| |
| ecs->event_thread = tp; |
| ecs->ptid = tp->ptid; |
| context_switch (ecs->ptid); |
| keep_going (ecs); |
| return; |
| } |
| } |
| |
| if (ecs->event_thread->control.step_resume_breakpoint) |
| { |
| if (debug_infrun) |
| fprintf_unfiltered (gdb_stdlog, |
| "infrun: step-resume breakpoint is inserted\n"); |
| |
| /* Having a step-resume breakpoint overrides anything |
| else having to do with stepping commands until |
| that breakpoint is reached. */ |
| keep_going (ecs); |
| return; |
| } |
| |
| if (ecs->event_thread->control.step_range_end == 0) |
| { |
| if (debug_infrun) |
| fprintf_unfiltered (gdb_stdlog, "infrun: no stepping, continue\n"); |
| /* Likewise if we aren't even stepping. */ |
| keep_going (ecs); |
| return; |
| } |
| |
| /* Re-fetch current thread's frame in case the code above caused |
| the frame cache to be re-initialized, making our FRAME variable |
| a dangling pointer. */ |
| frame = get_current_frame (); |
| gdbarch = get_frame_arch (frame); |
| fill_in_stop_func (gdbarch, ecs); |
| |
| /* If stepping through a line, keep going if still within it. |
| |
| Note that step_range_end is the address of the first instruction |
| beyond the step range, and NOT the address of the last instruction |
| within it! |
| |
| Note also that during reverse execution, we may be stepping |
| through a function epilogue and therefore must detect when |
| the current-frame changes in the middle of a line. */ |
| |
| if (stop_pc >= ecs->event_thread->control.step_range_start |
| && stop_pc < ecs->event_thread->control.step_range_end |
| && (execution_direction != EXEC_REVERSE |
| || frame_id_eq (get_frame_id (frame), |
| ecs->event_thread->control.step_frame_id))) |
| { |
| if (debug_infrun) |
| fprintf_unfiltered |
| (gdb_stdlog, "infrun: stepping inside range [%s-%s]\n", |
| paddress (gdbarch, ecs->event_thread->control.step_range_start), |
| paddress (gdbarch, ecs->event_thread->control.step_range_end)); |
| |
| /* When stepping backward, stop at beginning of line range |
| (unless it's the function entry point, in which case |
| keep going back to the call point). */ |
| if (stop_pc == ecs->event_thread->control.step_range_start |
| && stop_pc != ecs->stop_func_start |
| && execution_direction == EXEC_REVERSE) |
| { |
| ecs->event_thread->control.stop_step = 1; |
| print_end_stepping_range_reason (); |
| stop_stepping (ecs); |
| } |
| else |
| keep_going (ecs); |
| |
| return; |
| } |
| |
| /* We stepped out of the stepping range. */ |
| |
| /* If we are stepping at the source level and entered the runtime |
| loader dynamic symbol resolution code... |
| |
| EXEC_FORWARD: we keep on single stepping until we exit the run |
| time loader code and reach the callee's address. |
| |
| EXEC_REVERSE: we've already executed the callee (backward), and |
| the runtime loader code is handled just like any other |
| undebuggable function call. Now we need only keep stepping |
| backward through the trampoline code, and that's handled further |
| down, so there is nothing for us to do here. */ |
| |
| if (execution_direction != EXEC_REVERSE |
| && ecs->event_thread->control.step_over_calls == STEP_OVER_UNDEBUGGABLE |
| && in_solib_dynsym_resolve_code (stop_pc)) |
| { |
| CORE_ADDR pc_after_resolver = |
| gdbarch_skip_solib_resolver (gdbarch, stop_pc); |
| |
| if (debug_infrun) |
| fprintf_unfiltered (gdb_stdlog, |
| "infrun: stepped into dynsym resolve code\n"); |
| |
| if (pc_after_resolver) |
| { |
| /* Set up a step-resume breakpoint at the address |
| indicated by SKIP_SOLIB_RESOLVER. */ |
| struct symtab_and_line sr_sal; |
| |
| init_sal (&sr_sal); |
| sr_sal.pc = pc_after_resolver; |
| sr_sal.pspace = get_frame_program_space (frame); |
| |
| insert_step_resume_breakpoint_at_sal (gdbarch, |
| sr_sal, null_frame_id); |
| } |
| |
| keep_going (ecs); |
| return; |
| } |
| |
| if (ecs->event_thread->control.step_range_end != 1 |
| && (ecs->event_thread->control.step_over_calls == STEP_OVER_UNDEBUGGABLE |
| || ecs->event_thread->control.step_over_calls == STEP_OVER_ALL) |
| && get_frame_type (frame) == SIGTRAMP_FRAME) |
| { |
| if (debug_infrun) |
| fprintf_unfiltered (gdb_stdlog, |
| "infrun: stepped into signal trampoline\n"); |
| /* The inferior, while doing a "step" or "next", has ended up in |
| a signal trampoline (either by a signal being delivered or by |
| the signal handler returning). Just single-step until the |
| inferior leaves the trampoline (either by calling the handler |
| or returning). */ |
| keep_going (ecs); |
| return; |
| } |
| |
| /* If we're in the return path from a shared library trampoline, |
| we want to proceed through the trampoline when stepping. */ |
| /* macro/2012-04-25: This needs to come before the subroutine |
| call check below as on some targets return trampolines look |
| like subroutine calls (MIPS16 return thunks). */ |
| if (gdbarch_in_solib_return_trampoline (gdbarch, |
| stop_pc, ecs->stop_func_name) |
| && ecs->event_thread->control.step_over_calls != STEP_OVER_NONE) |
| { |
| /* Determine where this trampoline returns. */ |
| CORE_ADDR real_stop_pc; |
| |
| real_stop_pc = gdbarch_skip_trampoline_code (gdbarch, frame, stop_pc); |
| |
| if (debug_infrun) |
| fprintf_unfiltered (gdb_stdlog, |
| "infrun: stepped into solib return tramp\n"); |
| |
| /* Only proceed through if we know where it's going. */ |
| if (real_stop_pc) |
| { |
| /* And put the step-breakpoint there and go until there. */ |
| struct symtab_and_line sr_sal; |
| |
| init_sal (&sr_sal); /* initialize to zeroes */ |
| sr_sal.pc = real_stop_pc; |
| sr_sal.section = find_pc_overlay (sr_sal.pc); |
| sr_sal.pspace = get_frame_program_space (frame); |
| |
| /* Do not specify what the fp should be when we stop since |
| on some machines the prologue is where the new fp value |
| is established. */ |
| insert_step_resume_breakpoint_at_sal (gdbarch, |
| sr_sal, null_frame_id); |
| |
| /* Restart without fiddling with the step ranges or |
| other state. */ |
| keep_going (ecs); |
| return; |
| } |
| } |
| |
| /* Check for subroutine calls. The check for the current frame |
| equalling the step ID is not necessary - the check of the |
| previous frame's ID is sufficient - but it is a common case and |
| cheaper than checking the previous frame's ID. |
| |
| NOTE: frame_id_eq will never report two invalid frame IDs as |
| being equal, so to get into this block, both the current and |
| previous frame must have valid frame IDs. */ |
| /* The outer_frame_id check is a heuristic to detect stepping |
| through startup code. If we step over an instruction which |
| sets the stack pointer from an invalid value to a valid value, |
| we may detect that as a subroutine call from the mythical |
| "outermost" function. This could be fixed by marking |
| outermost frames as !stack_p,code_p,special_p. Then the |
| initial outermost frame, before sp was valid, would |
| have code_addr == &_start. See the comment in frame_id_eq |
| for more. */ |
| if (!frame_id_eq (get_stack_frame_id (frame), |
| ecs->event_thread->control.step_stack_frame_id) |
| && (frame_id_eq (frame_unwind_caller_id (get_current_frame ()), |
| ecs->event_thread->control.step_stack_frame_id) |
| && (!frame_id_eq (ecs->event_thread->control.step_stack_frame_id, |
| outer_frame_id) |
| || step_start_function != find_pc_function (stop_pc)))) |
| { |
| CORE_ADDR real_stop_pc; |
| |
| if (debug_infrun) |
| fprintf_unfiltered (gdb_stdlog, "infrun: stepped into subroutine\n"); |
| |
| if ((ecs->event_thread->control.step_over_calls == STEP_OVER_NONE) |
| || ((ecs->event_thread->control.step_range_end == 1) |
| && in_prologue (gdbarch, ecs->event_thread->prev_pc, |
| ecs->stop_func_start))) |
| { |
| /* I presume that step_over_calls is only 0 when we're |
| supposed to be stepping at the assembly language level |
| ("stepi"). Just stop. */ |
| /* Also, maybe we just did a "nexti" inside a prolog, so we |
| thought it was a subroutine call but it was not. Stop as |
| well. FENN */ |
| /* And this works the same backward as frontward. MVS */ |
| ecs->event_thread->control.stop_step = 1; |
| print_end_stepping_range_reason (); |
| stop_stepping (ecs); |
| return; |
| } |
| |
| /* Reverse stepping through solib trampolines. */ |
| |
| if (execution_direction == EXEC_REVERSE |
| && ecs->event_thread->control.step_over_calls != STEP_OVER_NONE |
| && (gdbarch_skip_trampoline_code (gdbarch, frame, stop_pc) |
| || (ecs->stop_func_start == 0 |
| && in_solib_dynsym_resolve_code (stop_pc)))) |
| { |
| /* Any solib trampoline code can be handled in reverse |
| by simply continuing to single-step. We have already |
| executed the solib function (backwards), and a few |
| steps will take us back through the trampoline to the |
| caller. */ |
| keep_going (ecs); |
| return; |
| } |
| |
| if (ecs->event_thread->control.step_over_calls == STEP_OVER_ALL) |
| { |
| /* We're doing a "next". |
| |
| Normal (forward) execution: set a breakpoint at the |
| callee's return address (the address at which the caller |
| will resume). |
| |
| Reverse (backward) execution. set the step-resume |
| breakpoint at the start of the function that we just |
| stepped into (backwards), and continue to there. When we |
| get there, we'll need to single-step back to the caller. */ |
| |
| if (execution_direction == EXEC_REVERSE) |
| { |
| struct symtab_and_line sr_sal; |
| |
| /* Normal function call return (static or dynamic). */ |
| init_sal (&sr_sal); |
| sr_sal.pc = ecs->stop_func_start; |
| sr_sal.pspace = get_frame_program_space (frame); |
| insert_step_resume_breakpoint_at_sal (gdbarch, |
| sr_sal, null_frame_id); |
| } |
| else |
| insert_step_resume_breakpoint_at_caller (frame); |
| |
| keep_going (ecs); |
| return; |
| } |
| |
| /* If we are in a function call trampoline (a stub between the |
| calling routine and the real function), locate the real |
| function. That's what tells us (a) whether we want to step |
| into it at all, and (b) what prologue we want to run to the |
| end of, if we do step into it. */ |
| real_stop_pc = skip_language_trampoline (frame, stop_pc); |
| if (real_stop_pc == 0) |
| real_stop_pc = gdbarch_skip_trampoline_code (gdbarch, frame, stop_pc); |
| if (real_stop_pc != 0) |
| ecs->stop_func_start = real_stop_pc; |
| |
| if (real_stop_pc != 0 && in_solib_dynsym_resolve_code (real_stop_pc)) |
| { |
| struct symtab_and_line sr_sal; |
| |
| init_sal (&sr_sal); |
| sr_sal.pc = ecs->stop_func_start; |
| sr_sal.pspace = get_frame_program_space (frame); |
| |
| insert_step_resume_breakpoint_at_sal (gdbarch, |
| sr_sal, null_frame_id); |
| keep_going (ecs); |
| return; |
| } |
| |
| /* If we have line number information for the function we are |
| thinking of stepping into and the function isn't on the skip |
| list, step into it. |
| |
| If there are several symtabs at that PC (e.g. with include |
| files), just want to know whether *any* of them have line |
| numbers. find_pc_line handles this. */ |
| { |
| struct symtab_and_line tmp_sal; |
| |
| tmp_sal = find_pc_line (ecs->stop_func_start, 0); |
| if (tmp_sal.line != 0 |
| && !function_pc_is_marked_for_skip (ecs->stop_func_start)) |
| { |
| if (execution_direction == EXEC_REVERSE) |
| handle_step_into_function_backward (gdbarch, ecs); |
| else |
| handle_step_into_function (gdbarch, ecs); |
| return; |
| } |
| } |
| |
| /* If we have no line number and the step-stop-if-no-debug is |
| set, we stop the step so that the user has a chance to switch |
| in assembly mode. */ |
| if (ecs->event_thread->control.step_over_calls == STEP_OVER_UNDEBUGGABLE |
| && step_stop_if_no_debug) |
| { |
| ecs->event_thread->control.stop_step = 1; |
| print_end_stepping_range_reason (); |
| stop_stepping (ecs); |
| return; |
| } |
| |
| if (execution_direction == EXEC_REVERSE) |
| { |
| /* Set a breakpoint at callee's start address. |
| From there we can step once and be back in the caller. */ |
| struct symtab_and_line sr_sal; |
| |
| init_sal (&sr_sal); |
| sr_sal.pc = ecs->stop_func_start; |
| sr_sal.pspace = get_frame_program_space (frame); |
| insert_step_resume_breakpoint_at_sal (gdbarch, |
| sr_sal, null_frame_id); |
| } |
| else |
| /* Set a breakpoint at callee's return address (the address |
| at which the caller will resume). */ |
| insert_step_resume_breakpoint_at_caller (frame); |
| |
| keep_going (ecs); |
| return; |
| } |
| |
| /* Reverse stepping through solib trampolines. */ |
| |
| if (execution_direction == EXEC_REVERSE |
| && ecs->event_thread->control.step_over_calls != STEP_OVER_NONE) |
| { |
| if (gdbarch_skip_trampoline_code (gdbarch, frame, stop_pc) |
| || (ecs->stop_func_start == 0 |
| && in_solib_dynsym_resolve_code (stop_pc))) |
| { |
| /* Any solib trampoline code can be handled in reverse |
| by simply continuing to single-step. We have already |
| executed the solib function (backwards), and a few |
| steps will take us back through the trampoline to the |
| caller. */ |
| keep_going (ecs); |
| return; |
| } |
| else if (in_solib_dynsym_resolve_code (stop_pc)) |
| { |
| /* Stepped backward into the solib dynsym resolver. |
| Set a breakpoint at its start and continue, then |
| one more step will take us out. */ |
| struct symtab_and_line sr_sal; |
| |
| init_sal (&sr_sal); |
| sr_sal.pc = ecs->stop_func_start; |
| sr_sal.pspace = get_frame_program_space (frame); |
| insert_step_resume_breakpoint_at_sal (gdbarch, |
| sr_sal, null_frame_id); |
| keep_going (ecs); |
| return; |
| } |
| } |
| |
| stop_pc_sal = find_pc_line (stop_pc, 0); |
| |
| /* NOTE: tausq/2004-05-24: This if block used to be done before all |
| the trampoline processing logic, however, there are some trampolines |
| that have no names, so we should do trampoline handling first. */ |
| if (ecs->event_thread->control.step_over_calls == STEP_OVER_UNDEBUGGABLE |
| && ecs->stop_func_name == NULL |
| && stop_pc_sal.line == 0) |
| { |
| if (debug_infrun) |
| fprintf_unfiltered (gdb_stdlog, |
| "infrun: stepped into undebuggable function\n"); |
| |
| /* The inferior just stepped into, or returned to, an |
| undebuggable function (where there is no debugging information |
| and no line number corresponding to the address where the |
| inferior stopped). Since we want to skip this kind of code, |
| we keep going until the inferior returns from this |
| function - unless the user has asked us not to (via |
| set step-mode) or we no longer know how to get back |
| to the call site. */ |
| if (step_stop_if_no_debug |
| || !frame_id_p (frame_unwind_caller_id (frame))) |
| { |
| /* If we have no line number and the step-stop-if-no-debug |
| is set, we stop the step so that the user has a chance to |
| switch in assembly mode. */ |
| ecs->event_thread->control.stop_step = 1; |
| print_end_stepping_range_reason (); |
| stop_stepping (ecs); |
| return; |
| } |
| else |
| { |
| /* Set a breakpoint at callee's return address (the address |
| at which the caller will resume). */ |
| insert_step_resume_breakpoint_at_caller (frame); |
| keep_going (ecs); |
| return; |
| } |
| } |
| |
| if (ecs->event_thread->control.step_range_end == 1) |
| { |
| /* It is stepi or nexti. We always want to stop stepping after |
| one instruction. */ |
| if (debug_infrun) |
| fprintf_unfiltered (gdb_stdlog, "infrun: stepi/nexti\n"); |
| ecs->event_thread->control.stop_step = 1; |
| print_end_stepping_range_reason (); |
| stop_stepping (ecs); |
| return; |
| } |
| |
| if (stop_pc_sal.line == 0) |
| { |
| /* We have no line number information. That means to stop |
| stepping (does this always happen right after one instruction, |
| when we do "s" in a function with no line numbers, |
| or can this happen as a result of a return or longjmp?). */ |
| if (debug_infrun) |
| fprintf_unfiltered (gdb_stdlog, "infrun: no line number info\n"); |
| ecs->event_thread->control.stop_step = 1; |
| print_end_stepping_range_reason (); |
| stop_stepping (ecs); |
| return; |
| } |
| |
| /* Look for "calls" to inlined functions, part one. If the inline |
| frame machinery detected some skipped call sites, we have entered |
| a new inline function. */ |
| |
| if (frame_id_eq (get_frame_id (get_current_frame ()), |
| ecs->event_thread->control.step_frame_id) |
| && inline_skipped_frames (ecs->ptid)) |
| { |
| struct symtab_and_line call_sal; |
| |
| if (debug_infrun) |
| fprintf_unfiltered (gdb_stdlog, |
| "infrun: stepped into inlined function\n"); |
| |
| find_frame_sal (get_current_frame (), &call_sal); |
| |
| if (ecs->event_thread->control.step_over_calls != STEP_OVER_ALL) |
| { |
| /* For "step", we're going to stop. But if the call site |
| for this inlined function is on the same source line as |
| we were previously stepping, go down into the function |
| first. Otherwise stop at the call site. */ |
| |
| if (call_sal.line == ecs->event_thread->current_line |
| && call_sal.symtab == ecs->event_thread->current_symtab) |
| step_into_inline_frame (ecs->ptid); |
| |
| ecs->event_thread->control.stop_step = 1; |
| print_end_stepping_range_reason (); |
| stop_stepping (ecs); |
| return; |
| } |
| else |
| { |
| /* For "next", we should stop at the call site if it is on a |
| different source line. Otherwise continue through the |
| inlined function. */ |
| if (call_sal.line == ecs->event_thread->current_line |
| && call_sal.symtab == ecs->event_thread->current_symtab) |
| keep_going (ecs); |
| else |
| { |
| ecs->event_thread->control.stop_step = 1; |
| print_end_stepping_range_reason (); |
| stop_stepping (ecs); |
| } |
| return; |
| } |
| } |
| |
| /* Look for "calls" to inlined functions, part two. If we are still |
| in the same real function we were stepping through, but we have |
| to go further up to find the exact frame ID, we are stepping |
| through a more inlined call beyond its call site. */ |
| |
| if (get_frame_type (get_current_frame ()) == INLINE_FRAME |
| && !frame_id_eq (get_frame_id (get_current_frame ()), |
| ecs->event_thread->control.step_frame_id) |
| && stepped_in_from (get_current_frame (), |
| ecs->event_thread->control.step_frame_id)) |
| { |
| if (debug_infrun) |
| fprintf_unfiltered (gdb_stdlog, |
| "infrun: stepping through inlined function\n"); |
| |
| if (ecs->event_thread->control.step_over_calls == STEP_OVER_ALL) |
| keep_going (ecs); |
| else |
| { |
| ecs->event_thread->control.stop_step = 1; |
| print_end_stepping_range_reason (); |
| stop_stepping (ecs); |
| } |
| return; |
| } |
| |
| if ((stop_pc == stop_pc_sal.pc) |
| && (ecs->event_thread->current_line != stop_pc_sal.line |
| || ecs->event_thread->current_symtab != stop_pc_sal.symtab)) |
| { |
| /* We are at the start of a different line. So stop. Note that |
| we don't stop if we step into the middle of a different line. |
| That is said to make things like for (;;) statements work |
| better. */ |
| if (debug_infrun) |
| fprintf_unfiltered (gdb_stdlog, |
| "infrun: stepped to a different line\n"); |
| ecs->event_thread->control.stop_step = 1; |
| print_end_stepping_range_reason (); |
| stop_stepping (ecs); |
| return; |
| } |
| |
| /* We aren't done stepping. |
| |
| Optimize by setting the stepping range to the line. |
| (We might not be in the original line, but if we entered a |
| new line in mid-statement, we continue stepping. This makes |
| things like for(;;) statements work better.) */ |
| |
| ecs->event_thread->control.step_range_start = stop_pc_sal.pc; |
| ecs->event_thread->control.step_range_end = stop_pc_sal.end; |
| set_step_info (frame, stop_pc_sal); |
| |
| if (debug_infrun) |
| fprintf_unfiltered (gdb_stdlog, "infrun: keep going\n"); |
| keep_going (ecs); |
| } |
| |
| /* Is thread TP in the middle of single-stepping? */ |
| |
| static int |
| currently_stepping (struct thread_info *tp) |
| { |
| return ((tp->control.step_range_end |
| && tp->control.step_resume_breakpoint == NULL) |
| || tp->control.trap_expected |
| || bpstat_should_step ()); |
| } |
| |
| /* Returns true if any thread *but* the one passed in "data" is in the |
| middle of stepping or of handling a "next". */ |
| |
| static int |
| currently_stepping_or_nexting_callback (struct thread_info *tp, void *data) |
| { |
| if (tp == data) |
| return 0; |
| |
| return (tp->control.step_range_end |
| || tp->control.trap_expected); |
| } |
| |
| /* Inferior has stepped into a subroutine call with source code that |
| we should not step over. Do step to the first line of code in |
| it. */ |
| |
| static void |
| handle_step_into_function (struct gdbarch *gdbarch, |
| struct execution_control_state *ecs) |
| { |
| struct symtab *s; |
| struct symtab_and_line stop_func_sal, sr_sal; |
| |
| fill_in_stop_func (gdbarch, ecs); |
| |
| s = find_pc_symtab (stop_pc); |
| if (s && s->language != language_asm) |
| ecs->stop_func_start = gdbarch_skip_prologue (gdbarch, |
| ecs->stop_func_start); |
| |
| stop_func_sal = find_pc_line (ecs->stop_func_start, 0); |
| /* Use the step_resume_break to step until the end of the prologue, |
| even if that involves jumps (as it seems to on the vax under |
| 4.2). */ |
| /* If the prologue ends in the middle of a source line, continue to |
| the end of that source line (if it is still within the function). |
| Otherwise, just go to end of prologue. */ |
| if (stop_func_sal.end |
| && stop_func_sal.pc != ecs->stop_func_start |
| && stop_func_sal.end < ecs->stop_func_end) |
| ecs->stop_func_start = stop_func_sal.end; |
| |
| /* Architectures which require breakpoint adjustment might not be able |
| to place a breakpoint at the computed address. If so, the test |
| ``ecs->stop_func_start == stop_pc'' will never succeed. Adjust |
| ecs->stop_func_start to an address at which a breakpoint may be |
| legitimately placed. |
| |
| Note: kevinb/2004-01-19: On FR-V, if this adjustment is not |
| made, GDB will enter an infinite loop when stepping through |
| optimized code consisting of VLIW instructions which contain |
| subinstructions corresponding to different source lines. On |
| FR-V, it's not permitted to place a breakpoint on any but the |
| first subinstruction of a VLIW instruction. When a breakpoint is |
| set, GDB will adjust the breakpoint address to the beginning of |
| the VLIW instruction. Thus, we need to make the corresponding |
| adjustment here when computing the stop address. */ |
| |
| if (gdbarch_adjust_breakpoint_address_p (gdbarch)) |
| { |
| ecs->stop_func_start |
| = gdbarch_adjust_breakpoint_address (gdbarch, |
| ecs->stop_func_start); |
| } |
| |
| if (ecs->stop_func_start == stop_pc) |
| { |
| /* We are already there: stop now. */ |
| ecs->event_thread->control.stop_step = 1; |
| print_end_stepping_range_reason (); |
| stop_stepping (ecs); |
| return; |
| } |
| else |
| { |
| /* Put the step-breakpoint there and go until there. */ |
| init_sal (&sr_sal); /* initialize to zeroes */ |
| sr_sal.pc = ecs->stop_func_start; |
| sr_sal.section = find_pc_overlay (ecs->stop_func_start); |
| sr_sal.pspace = get_frame_program_space (get_current_frame ()); |
| |
| /* Do not specify what the fp should be when we stop since on |
| some machines the prologue is where the new fp value is |
| established. */ |
| insert_step_resume_breakpoint_at_sal (gdbarch, sr_sal, null_frame_id); |
| |
| /* And make sure stepping stops right away then. */ |
| ecs->event_thread->control.step_range_end |
| = ecs->event_thread->control.step_range_start; |
| } |
| keep_going (ecs); |
| } |
| |
| /* Inferior has stepped backward into a subroutine call with source |
| code that we should not step over. Do step to the beginning of the |
| last line of code in it. */ |
| |
| static void |
| handle_step_into_function_backward (struct gdbarch *gdbarch, |
| struct execution_control_state *ecs) |
| { |
| struct symtab *s; |
| struct symtab_and_line stop_func_sal; |
| |
| fill_in_stop_func (gdbarch, ecs); |
| |
| s = find_pc_symtab (stop_pc); |
| if (s && s->language != language_asm) |
| ecs->stop_func_start = gdbarch_skip_prologue (gdbarch, |
| ecs->stop_func_start); |
| |
| stop_func_sal = find_pc_line (stop_pc, 0); |
| |
| /* OK, we're just going to keep stepping here. */ |
| if (stop_func_sal.pc == stop_pc) |
| { |
| /* We're there already. Just stop stepping now. */ |
| ecs->event_thread->control.stop_step = 1; |
| print_end_stepping_range_reason (); |
| stop_stepping (ecs); |
| } |
| else |
| { |
| /* Else just reset the step range and keep going. |
| No step-resume breakpoint, they don't work for |
| epilogues, which can have multiple entry paths. */ |
| ecs->event_thread->control.step_range_start = stop_func_sal.pc; |
| ecs->event_thread->control.step_range_end = stop_func_sal.end; |
| keep_going (ecs); |
| } |
| return; |
| } |
| |
| /* Insert a "step-resume breakpoint" at SR_SAL with frame ID SR_ID. |
| This is used to both functions and to skip over code. */ |
| |
| static void |
| insert_step_resume_breakpoint_at_sal_1 (struct gdbarch *gdbarch, |
| struct symtab_and_line sr_sal, |
| struct frame_id sr_id, |
| enum bptype sr_type) |
| { |
| /* There should never be more than one step-resume or longjmp-resume |
| breakpoint per thread, so we should never be setting a new |
| step_resume_breakpoint when one is already active. */ |
| gdb_assert (inferior_thread ()->control.step_resume_breakpoint == NULL); |
| gdb_assert (sr_type == bp_step_resume || sr_type == bp_hp_step_resume); |
| |
| if (debug_infrun) |
| fprintf_unfiltered (gdb_stdlog, |
| "infrun: inserting step-resume breakpoint at %s\n", |
| paddress (gdbarch, sr_sal.pc)); |
| |
| inferior_thread ()->control.step_resume_breakpoint |
| = set_momentary_breakpoint (gdbarch, sr_sal, sr_id, sr_type); |
| } |
| |
| void |
| insert_step_resume_breakpoint_at_sal (struct gdbarch *gdbarch, |
| struct symtab_and_line sr_sal, |
| struct frame_id sr_id) |
| { |
| insert_step_resume_breakpoint_at_sal_1 (gdbarch, |
| sr_sal, sr_id, |
| bp_step_resume); |
| } |
| |
| /* Insert a "high-priority step-resume breakpoint" at RETURN_FRAME.pc. |
| This is used to skip a potential signal handler. |
| |
| This is called with the interrupted function's frame. The signal |
| handler, when it returns, will resume the interrupted function at |
| RETURN_FRAME.pc. */ |
| |
| static void |
| insert_hp_step_resume_breakpoint_at_frame (struct frame_info *return_frame) |
| { |
| struct symtab_and_line sr_sal; |
| struct gdbarch *gdbarch; |
| |
| gdb_assert (return_frame != NULL); |
| init_sal (&sr_sal); /* initialize to zeros */ |
| |
| gdbarch = get_frame_arch (return_frame); |
| sr_sal.pc = gdbarch_addr_bits_remove (gdbarch, get_frame_pc (return_frame)); |
| sr_sal.section = find_pc_overlay (sr_sal.pc); |
| sr_sal.pspace = get_frame_program_space (return_frame); |
| |
| insert_step_resume_breakpoint_at_sal_1 (gdbarch, sr_sal, |
| get_stack_frame_id (return_frame), |
| bp_hp_step_resume); |
| } |
| |
| /* Insert a "step-resume breakpoint" at the previous frame's PC. This |
| is used to skip a function after stepping into it (for "next" or if |
| the called function has no debugging information). |
| |
| The current function has almost always been reached by single |
| stepping a call or return instruction. NEXT_FRAME belongs to the |
| current function, and the breakpoint will be set at the caller's |
| resume address. |
| |
| This is a separate function rather than reusing |
| insert_hp_step_resume_breakpoint_at_frame in order to avoid |
| get_prev_frame, which may stop prematurely (see the implementation |
| of frame_unwind_caller_id for an example). */ |
| |
| static void |
| insert_step_resume_breakpoint_at_caller (struct frame_info *next_frame) |
| { |
| struct symtab_and_line sr_sal; |
| struct gdbarch *gdbarch; |
| |
| /* We shouldn't have gotten here if we don't know where the call site |
| is. */ |
| gdb_assert (frame_id_p (frame_unwind_caller_id (next_frame))); |
| |
| init_sal (&sr_sal); /* initialize to zeros */ |
| |
| gdbarch = frame_unwind_caller_arch (next_frame); |
| sr_sal.pc = gdbarch_addr_bits_remove (gdbarch, |
| frame_unwind_caller_pc (next_frame)); |
| sr_sal.section = find_pc_overlay (sr_sal.pc); |
| sr_sal.pspace = frame_unwind_program_space (next_frame); |
| |
| insert_step_resume_breakpoint_at_sal (gdbarch, sr_sal, |
| frame_unwind_caller_id (next_frame)); |
| } |
| |
| /* Insert a "longjmp-resume" breakpoint at PC. This is used to set a |
| new breakpoint at the target of a jmp_buf. The handling of |
| longjmp-resume uses the same mechanisms used for handling |
| "step-resume" breakpoints. */ |
| |
| static void |
| insert_longjmp_resume_breakpoint (struct gdbarch *gdbarch, CORE_ADDR pc) |
| { |
| /* There should never be more than one longjmp-resume breakpoint per |
| thread, so we should never be setting a new |
| longjmp_resume_breakpoint when one is already active. */ |
| gdb_assert (inferior_thread ()->control.exception_resume_breakpoint == NULL); |
| |
| if (debug_infrun) |
| fprintf_unfiltered (gdb_stdlog, |
| "infrun: inserting longjmp-resume breakpoint at %s\n", |
| paddress (gdbarch, pc)); |
| |
| inferior_thread ()->control.exception_resume_breakpoint = |
| set_momentary_breakpoint_at_pc (gdbarch, pc, bp_longjmp_resume); |
| } |
| |
| /* Insert an exception resume breakpoint. TP is the thread throwing |
| the exception. The block B is the block of the unwinder debug hook |
| function. FRAME is the frame corresponding to the call to this |
| function. SYM is the symbol of the function argument holding the |
| target PC of the exception. */ |
| |
| static void |
| insert_exception_resume_breakpoint (struct thread_info *tp, |
| struct block *b, |
| struct frame_info *frame, |
| struct symbol *sym) |
| { |
| volatile struct gdb_exception e; |
| |
| /* We want to ignore errors here. */ |
| TRY_CATCH (e, RETURN_MASK_ERROR) |
| { |
| struct symbol *vsym; |
| struct value *value; |
| CORE_ADDR handler; |
| struct breakpoint *bp; |
| |
| vsym = lookup_symbol (SYMBOL_LINKAGE_NAME (sym), b, VAR_DOMAIN, NULL); |
| value = read_var_value (vsym, frame); |
| /* If the value was optimized out, revert to the old behavior. */ |
| if (! value_optimized_out (value)) |
| { |
| handler = value_as_address (value); |
| |
| if (debug_infrun) |
| fprintf_unfiltered (gdb_stdlog, |
| "infrun: exception resume at %lx\n", |
| (unsigned long) handler); |
| |
| bp = set_momentary_breakpoint_at_pc (get_frame_arch (frame), |
| handler, bp_exception_resume); |
| |
| /* set_momentary_breakpoint_at_pc invalidates FRAME. */ |
| frame = NULL; |
| |
| bp->thread = tp->num; |
| inferior_thread ()->control.exception_resume_breakpoint = bp; |
| } |
| } |
| } |
| |
| /* A helper for check_exception_resume that sets an |
| exception-breakpoint based on a SystemTap probe. */ |
| |
| static void |
| insert_exception_resume_from_probe (struct thread_info *tp, |
| const struct probe *probe, |
| struct objfile *objfile, |
| struct frame_info *frame) |
| { |
| struct value *arg_value; |
| CORE_ADDR handler; |
| struct breakpoint *bp; |
| |
| arg_value = probe_safe_evaluate_at_pc (frame, 1); |
| if (!arg_value) |
| return; |
| |
| handler = value_as_address (arg_value); |
| |
| if (debug_infrun) |
| fprintf_unfiltered (gdb_stdlog, |
| "infrun: exception resume at %s\n", |
| paddress (get_objfile_arch (objfile), |
| handler)); |
| |
| bp = set_momentary_breakpoint_at_pc (get_frame_arch (frame), |
| handler, bp_exception_resume); |
| bp->thread = tp->num; |
| inferior_thread ()->control.exception_resume_breakpoint = bp; |
| } |
| |
| /* This is called when an exception has been intercepted. Check to |
| see whether the exception's destination is of interest, and if so, |
| set an exception resume breakpoint there. */ |
| |
| static void |
| check_exception_resume (struct execution_control_state *ecs, |
| struct frame_info *frame) |
| { |
| volatile struct gdb_exception e; |
| struct objfile *objfile; |
| const struct probe *probe; |
| struct symbol *func; |
| |
| /* First see if this exception unwinding breakpoint was set via a |
| SystemTap probe point. If so, the probe has two arguments: the |
| CFA and the HANDLER. We ignore the CFA, extract the handler, and |
| set a breakpoint there. */ |
| probe = find_probe_by_pc (get_frame_pc (frame), &objfile); |
| if (probe) |
| { |
| insert_exception_resume_from_probe (ecs->event_thread, probe, |
| objfile, frame); |
| return; |
| } |
| |
| func = get_frame_function (frame); |
| if (!func) |
| return; |
| |
| TRY_CATCH (e, RETURN_MASK_ERROR) |
| { |
| struct block *b; |
| struct block_iterator iter; |
| struct symbol *sym; |
| int argno = 0; |
| |
| /* The exception breakpoint is a thread-specific breakpoint on |
| the unwinder's debug hook, declared as: |
| |
| void _Unwind_DebugHook (void *cfa, void *handler); |
| |
| The CFA argument indicates the frame to which control is |
| about to be transferred. HANDLER is the destination PC. |
| |
| We ignore the CFA and set a temporary breakpoint at HANDLER. |
| This is not extremely efficient but it avoids issues in gdb |
| with computing the DWARF CFA, and it also works even in weird |
| cases such as throwing an exception from inside a signal |
| handler. */ |
| |
| b = SYMBOL_BLOCK_VALUE (func); |
| ALL_BLOCK_SYMBOLS (b, iter, sym) |
| { |
| if (!SYMBOL_IS_ARGUMENT (sym)) |
| continue; |
| |
| if (argno == 0) |
| ++argno; |
| else |
| { |
| insert_exception_resume_breakpoint (ecs->event_thread, |
| b, frame, sym); |
| break; |
| } |
| } |
| } |
| } |
| |
| static void |
| stop_stepping (struct execution_control_state *ecs) |
| { |
| if (debug_infrun) |
| fprintf_unfiltered (gdb_stdlog, "infrun: stop_stepping\n"); |
| |
| /* Let callers know we don't want to wait for the inferior anymore. */ |
| ecs->wait_some_more = 0; |
| } |
| |
| /* This function handles various cases where we need to continue |
| waiting for the inferior. */ |
| /* (Used to be the keep_going: label in the old wait_for_inferior). */ |
| |
| static void |
| keep_going (struct execution_control_state *ecs) |
| { |
| /* Make sure normal_stop is called if we get a QUIT handled before |
| reaching resume. */ |
| struct cleanup *old_cleanups = make_cleanup (resume_cleanups, 0); |
| |
| /* Save the pc before execution, to compare with pc after stop. */ |
| ecs->event_thread->prev_pc |
| = regcache_read_pc (get_thread_regcache (ecs->ptid)); |
| |
| /* If we did not do break;, it means we should keep running the |
| inferior and not return to debugger. */ |
| |
| if (ecs->event_thread->control.trap_expected |
| && ecs->event_thread->suspend.stop_signal != GDB_SIGNAL_TRAP) |
| { |
| /* We took a signal (which we are supposed to pass through to |
| the inferior, else we'd not get here) and we haven't yet |
| gotten our trap. Simply continue. */ |
| |
| discard_cleanups (old_cleanups); |
| resume (currently_stepping (ecs->event_thread), |
| ecs->event_thread->suspend.stop_signal); |
| } |
| else |
| { |
| /* Either the trap was not expected, but we are continuing |
| anyway (the user asked that this signal be passed to the |
| child) |
| -- or -- |
| The signal was SIGTRAP, e.g. it was our signal, but we |
| decided we should resume from it. |
| |
| We're going to run this baby now! |
| |
| Note that insert_breakpoints won't try to re-insert |
| already inserted breakpoints. Therefore, we don't |
| care if breakpoints were already inserted, or not. */ |
| |
| if (ecs->event_thread->stepping_over_breakpoint) |
| { |
| struct regcache *thread_regcache = get_thread_regcache (ecs->ptid); |
| |
| if (!use_displaced_stepping (get_regcache_arch (thread_regcache))) |
| /* Since we can't do a displaced step, we have to remove |
| the breakpoint while we step it. To keep things |
| simple, we remove them all. */ |
| remove_breakpoints (); |
| } |
| else |
| { |
| volatile struct gdb_exception e; |
| |
| /* Stop stepping when inserting breakpoints |
| has failed. */ |
| TRY_CATCH (e, RETURN_MASK_ERROR) |
| { |
| insert_breakpoints (); |
| } |
| if (e.reason < 0) |
| { |
| exception_print (gdb_stderr, e); |
| stop_stepping (ecs); |
| return; |
| } |
| } |
| |
| ecs->event_thread->control.trap_expected |
| = ecs->event_thread->stepping_over_breakpoint; |
| |
| /* Do not deliver SIGNAL_TRAP (except when the user explicitly |
| specifies that such a signal should be delivered to the |
| target program). |
| |
| Typically, this would occure when a user is debugging a |
| target monitor on a simulator: the target monitor sets a |
| breakpoint; the simulator encounters this break-point and |
| halts the simulation handing control to GDB; GDB, noteing |
| that the break-point isn't valid, returns control back to the |
| simulator; the simulator then delivers the hardware |
| equivalent of a SIGNAL_TRAP to the program being debugged. */ |
| |
| if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP |
| && !signal_program[ecs->event_thread->suspend.stop_signal]) |
| ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0; |
| |
| discard_cleanups (old_cleanups); |
| resume (currently_stepping (ecs->event_thread), |
| ecs->event_thread->suspend.stop_signal); |
| } |
| |
| prepare_to_wait (ecs); |
| } |
| |
| /* This function normally comes after a resume, before |
| handle_inferior_event exits. It takes care of any last bits of |
| housekeeping, and sets the all-important wait_some_more flag. */ |
| |
| static void |
| prepare_to_wait (struct execution_control_state *ecs) |
| { |
| if (debug_infrun) |
| fprintf_unfiltered (gdb_stdlog, "infrun: prepare_to_wait\n"); |
| |
| /* This is the old end of the while loop. Let everybody know we |
| want to wait for the inferior some more and get called again |
| soon. */ |
| ecs->wait_some_more = 1; |
| } |
| |
| /* Several print_*_reason functions to print why the inferior has stopped. |
| We always print something when the inferior exits, or receives a signal. |
| The rest of the cases are dealt with later on in normal_stop and |
| print_it_typical. Ideally there should be a call to one of these |
| print_*_reason functions functions from handle_inferior_event each time |
| stop_stepping is called. */ |
| |
| /* Print why the inferior has stopped. |
| We are done with a step/next/si/ni command, print why the inferior has |
| stopped. For now print nothing. Print a message only if not in the middle |
| of doing a "step n" operation for n > 1. */ |
| |
| static void |
| print_end_stepping_range_reason (void) |
| { |
| if ((!inferior_thread ()->step_multi |
| || !inferior_thread ()->control.stop_step) |
| && ui_out_is_mi_like_p (current_uiout)) |
| ui_out_field_string (current_uiout, "reason", |
| async_reason_lookup (EXEC_ASYNC_END_STEPPING_RANGE)); |
| } |
| |
| /* The inferior was terminated by a signal, print why it stopped. */ |
| |
| static void |
| print_signal_exited_reason (enum gdb_signal siggnal) |
| { |
| struct ui_out *uiout = current_uiout; |
| |
| annotate_signalled (); |
| if (ui_out_is_mi_like_p (uiout)) |
| ui_out_field_string |
| (uiout, "reason", async_reason_lookup (EXEC_ASYNC_EXITED_SIGNALLED)); |
| ui_out_text (uiout, "\nProgram terminated with signal "); |
| annotate_signal_name (); |
| ui_out_field_string (uiout, "signal-name", |
| gdb_signal_to_name (siggnal)); |
| annotate_signal_name_end (); |
| ui_out_text (uiout, ", "); |
| annotate_signal_string (); |
| ui_out_field_string (uiout, "signal-meaning", |
| gdb_signal_to_string (siggnal)); |
| annotate_signal_string_end (); |
| ui_out_text (uiout, ".\n"); |
| ui_out_text (uiout, "The program no longer exists.\n"); |
| } |
| |
| /* The inferior program is finished, print why it stopped. */ |
| |
| static void |
| print_exited_reason (int exitstatus) |
| { |
| struct inferior *inf = current_inferior (); |
| const char *pidstr = target_pid_to_str (pid_to_ptid (inf->pid)); |
| struct ui_out *uiout = current_uiout; |
| |
| annotate_exited (exitstatus); |
| if (exitstatus) |
| { |
| if (ui_out_is_mi_like_p (uiout)) |
| ui_out_field_string (uiout, "reason", |
| async_reason_lookup (EXEC_ASYNC_EXITED)); |
| ui_out_text (uiout, "[Inferior "); |
| ui_out_text (uiout, plongest (inf->num)); |
| ui_out_text (uiout, " ("); |
| ui_out_text (uiout, pidstr); |
| ui_out_text (uiout, ") exited with code "); |
| ui_out_field_fmt (uiout, "exit-code", "0%o", (unsigned int) exitstatus); |
| ui_out_text (uiout, "]\n"); |
| } |
| else |
| { |
| if (ui_out_is_mi_like_p (uiout)) |
| ui_out_field_string |
| (uiout, "reason", async_reason_lookup (EXEC_ASYNC_EXITED_NORMALLY)); |
| ui_out_text (uiout, "[Inferior "); |
| ui_out_text (uiout, plongest (inf->num)); |
| ui_out_text (uiout, " ("); |
| ui_out_text (uiout, pidstr); |
| ui_out_text (uiout, ") exited normally]\n"); |
| } |
| /* Support the --return-child-result option. */ |
| return_child_result_value = exitstatus; |
| } |
| |
| /* Signal received, print why the inferior has stopped. The signal table |
| tells us to print about it. */ |
| |
| static void |
| print_signal_received_reason (enum gdb_signal siggnal) |
| { |
| struct ui_out *uiout = current_uiout; |
| |
| annotate_signal (); |
| |
| if (siggnal == GDB_SIGNAL_0 && !ui_out_is_mi_like_p (uiout)) |
| { |
| struct thread_info *t = inferior_thread (); |
| |
| ui_out_text (uiout, "\n["); |
| ui_out_field_string (uiout, "thread-name", |
| target_pid_to_str (t->ptid)); |
| ui_out_field_fmt (uiout, "thread-id", "] #%d", t->num); |
| ui_out_text (uiout, " stopped"); |
| } |
| else |
| { |
| ui_out_text (uiout, "\nProgram received signal "); |
| annotate_signal_name (); |
| if (ui_out_is_mi_like_p (uiout)) |
| ui_out_field_string |
| (uiout, "reason", async_reason_lookup (EXEC_ASYNC_SIGNAL_RECEIVED)); |
| ui_out_field_string (uiout, "signal-name", |
| gdb_signal_to_name (siggnal)); |
| annotate_signal_name_end (); |
| ui_out_text (uiout, ", "); |
| annotate_signal_string (); |
| ui_out_field_string (uiout, "signal-meaning", |
| gdb_signal_to_string (siggnal)); |
| annotate_signal_string_end (); |
| } |
| ui_out_text (uiout, ".\n"); |
| } |
| |
| /* Reverse execution: target ran out of history info, print why the inferior |
| has stopped. */ |
| |
| static void |
| print_no_history_reason (void) |
| { |
| ui_out_text (current_uiout, "\nNo more reverse-execution history.\n"); |
| } |
| |
| /* Here to return control to GDB when the inferior stops for real. |
| Print appropriate messages, remove breakpoints, give terminal our modes. |
| |
| STOP_PRINT_FRAME nonzero means print the executing frame |
| (pc, function, args, file, line number and line text). |
| BREAKPOINTS_FAILED nonzero means stop was due to error |
| attempting to insert breakpoints. */ |
| |
| void |
| normal_stop (void) |
| { |
| struct target_waitstatus last; |
| ptid_t last_ptid; |
| struct cleanup *old_chain = make_cleanup (null_cleanup, NULL); |
| |
| get_last_target_status (&last_ptid, &last); |
| |
| /* If an exception is thrown from this point on, make sure to |
| propagate GDB's knowledge of the executing state to the |
| frontend/user running state. A QUIT is an easy exception to see |
| here, so do this before any filtered output. */ |
| if (!non_stop) |
| make_cleanup (finish_thread_state_cleanup, &minus_one_ptid); |
| else if (last.kind != TARGET_WAITKIND_SIGNALLED |
| && last.kind != TARGET_WAITKIND_EXITED |
| && last.kind != TARGET_WAITKIND_NO_RESUMED) |
| make_cleanup (finish_thread_state_cleanup, &inferior_ptid); |
| |
| /* In non-stop mode, we don't want GDB to switch threads behind the |
| user's back, to avoid races where the user is typing a command to |
| apply to thread x, but GDB switches to thread y before the user |
| finishes entering the command. */ |
| |
| /* As with the notification of thread events, we want to delay |
| notifying the user that we've switched thread context until |
| the inferior actually stops. |
| |
| There's no point in saying anything if the inferior has exited. |
| Note that SIGNALLED here means "exited with a signal", not |
| "received a signal". */ |
| if (!non_stop |
| && !ptid_equal (previous_inferior_ptid, inferior_ptid) |
| && target_has_execution |
| && last.kind != TARGET_WAITKIND_SIGNALLED |
| && last.kind != TARGET_WAITKIND_EXITED |
| && last.kind != TARGET_WAITKIND_NO_RESUMED) |
| { |
| target_terminal_ours_for_output (); |
| printf_filtered (_("[Switching to %s]\n"), |
| target_pid_to_str (inferior_ptid)); |
| annotate_thread_changed (); |
| previous_inferior_ptid = inferior_ptid; |
| } |
| |
| if (last.kind == TARGET_WAITKIND_NO_RESUMED) |
| { |
| gdb_assert (sync_execution || !target_can_async_p ()); |
| |
| target_terminal_ours_for_output (); |
| printf_filtered (_("No unwaited-for children left.\n")); |
| } |
| |
| if (!breakpoints_always_inserted_mode () && target_has_execution) |
| { |
| if (remove_breakpoints ()) |
| { |
| target_terminal_ours_for_output (); |
| printf_filtered (_("Cannot remove breakpoints because " |
| "program is no longer writable.\nFurther " |
| "execution is probably impossible.\n")); |
| } |
| } |
| |
| /* If an auto-display called a function and that got a signal, |
| delete that auto-display to avoid an infinite recursion. */ |
| |
| if (stopped_by_random_signal) |
| disable_current_display (); |
| |
| /* Don't print a message if in the middle of doing a "step n" |
| operation for n > 1 */ |
| if (target_has_execution |
| && last.kind != TARGET_WAITKIND_SIGNALLED |
| && last.kind != TARGET_WAITKIND_EXITED |
| && inferior_thread ()->step_multi |
| && inferior_thread ()->control.stop_step) |
| goto done; |
| |
| target_terminal_ours (); |
| async_enable_stdin (); |
| |
| /* Set the current source location. This will also happen if we |
| display the frame below, but the current SAL will be incorrect |
| during a user hook-stop function. */ |
| if (has_stack_frames () && !stop_stack_dummy) |
| set_current_sal_from_frame (get_current_frame (), 1); |
| |
| /* Let the user/frontend see the threads as stopped. */ |
| do_cleanups (old_chain); |
| |
| /* Look up the hook_stop and run it (CLI internally handles problem |
| of stop_command's pre-hook not existing). */ |
| if (stop_command) |
| catch_errors (hook_stop_stub, stop_command, |
| "Error while running hook_stop:\n", RETURN_MASK_ALL); |
| |
| if (!has_stack_frames ()) |
| goto done; |
| |
| if (last.kind == TARGET_WAITKIND_SIGNALLED |
| || last.kind == TARGET_WAITKIND_EXITED) |
| goto done; |
| |
| /* Select innermost stack frame - i.e., current frame is frame 0, |
| and current location is based on that. |
| Don't do this on return from a stack dummy routine, |
| or if the program has exited. */ |
| |
| if (!stop_stack_dummy) |
| { |
| select_frame (get_current_frame ()); |
| |
| /* Print current location without a level number, if |
| we have changed functions or hit a breakpoint. |
| Print source line if we have one. |
| bpstat_print() contains the logic deciding in detail |
| what to print, based on the event(s) that just occurred. */ |
| |
| /* If --batch-silent is enabled then there's no need to print the current |
| source location, and to try risks causing an error message about |
| missing source files. */ |
| if (stop_print_frame && !batch_silent) |
| { |
| int bpstat_ret; |
| int source_flag; |
| int do_frame_printing = 1; |
| struct thread_info *tp = inferior_thread (); |
| |
| bpstat_ret = bpstat_print (tp->control.stop_bpstat, last.kind); |
| switch (bpstat_ret) |
| { |
| case PRINT_UNKNOWN: |
| /* FIXME: cagney/2002-12-01: Given that a frame ID does |
| (or should) carry around the function and does (or |
| should) use that when doing a frame comparison. */ |
| if (tp->control.stop_step |
| && frame_id_eq (tp->control.step_frame_id, |
| get_frame_id (get_current_frame ())) |
| && step_start_function == find_pc_function (stop_pc)) |
| source_flag = SRC_LINE; /* Finished step, just |
| print source line. */ |
| else |
| source_flag = SRC_AND_LOC; /* Print location and |
| source line. */ |
| break; |
| case PRINT_SRC_AND_LOC: |
| source_flag = SRC_AND_LOC; /* Print location and |
| source line. */ |
| break; |
| case PRINT_SRC_ONLY: |
| source_flag = SRC_LINE; |
| break; |
| case PRINT_NOTHING: |
| source_flag = SRC_LINE; /* something bogus */ |
| do_frame_printing = 0; |
| break; |
| default: |
| internal_error (__FILE__, __LINE__, _("Unknown value.")); |
| } |
| |
| /* The behavior of this routine with respect to the source |
| flag is: |
| SRC_LINE: Print only source line |
| LOCATION: Print only location |
| SRC_AND_LOC: Print location and source line. */ |
| if (do_frame_printing) |
| print_stack_frame (get_selected_frame (NULL), 0, source_flag); |
| |
| /* Display the auto-display expressions. */ |
| do_displays (); |
| } |
| } |
| |
| /* Save the function value return registers, if we care. |
| We might be about to restore their previous contents. */ |
| if (inferior_thread ()->control.proceed_to_finish |
| && execution_direction != EXEC_REVERSE) |
| { |
| /* This should not be necessary. */ |
| if (stop_registers) |
| regcache_xfree (stop_registers); |
| |
| /* NB: The copy goes through to the target picking up the value of |
| all the registers. */ |
| stop_registers = regcache_dup (get_current_regcache ()); |
| } |
| |
| if (stop_stack_dummy == STOP_STACK_DUMMY) |
| { |
| /* Pop the empty frame that contains the stack dummy. |
| This also restores inferior state prior to the call |
| (struct infcall_suspend_state). */ |
| struct frame_info *frame = get_current_frame (); |
| |
| gdb_assert (get_frame_type (frame) == DUMMY_FRAME); |
| frame_pop (frame); |
| /* frame_pop() calls reinit_frame_cache as the last thing it |
| does which means there's currently no selected frame. We |
| don't need to re-establish a selected frame if the dummy call |
| returns normally, that will be done by |
| restore_infcall_control_state. However, we do have to handle |
| the case where the dummy call is returning after being |
| stopped (e.g. the dummy call previously hit a breakpoint). |
| We can't know which case we have so just always re-establish |
| a selected frame here. */ |
| select_frame (get_current_frame ()); |
| } |
| |
| done: |
| annotate_stopped (); |
| |
| /* Suppress the stop observer if we're in the middle of: |
| |
| - a step n (n > 1), as there still more steps to be done. |
| |
| - a "finish" command, as the observer will be called in |
| finish_command_continuation, so it can include the inferior |
| function's return value. |
| |
| - calling an inferior function, as we pretend we inferior didn't |
| run at all. The return value of the call is handled by the |
| expression evaluator, through call_function_by_hand. */ |
| |
| if (!target_has_execution |
| || last.kind == TARGET_WAITKIND_SIGNALLED |
| || last.kind == TARGET_WAITKIND_EXITED |
| || last.kind == TARGET_WAITKIND_NO_RESUMED |
| || (!(inferior_thread ()->step_multi |
| && inferior_thread ()->control.stop_step) |
| && !(inferior_thread ()->control.stop_bpstat |
| && inferior_thread ()->control.proceed_to_finish) |
| && !inferior_thread ()->control.in_infcall)) |
| { |
| if (!ptid_equal (inferior_ptid, null_ptid)) |
| observer_notify_normal_stop (inferior_thread ()->control.stop_bpstat, |
| stop_print_frame); |
| else |
| observer_notify_normal_stop (NULL, stop_print_frame); |
| } |
| |
| if (target_has_execution) |
| { |
| if (last.kind != TARGET_WAITKIND_SIGNALLED |
| && last.kind != TARGET_WAITKIND_EXITED) |
| /* Delete the breakpoint we stopped at, if it wants to be deleted. |
| Delete any breakpoint that is to be deleted at the next stop. */ |
| breakpoint_auto_delete (inferior_thread ()->control.stop_bpstat); |
| } |
| |
| /* Try to get rid of automatically added inferiors that are no |
| longer needed. Keeping those around slows down things linearly. |
| Note that this never removes the current inferior. */ |
| prune_inferiors (); |
| } |
| |
| static int |
| hook_stop_stub (void *cmd) |
| { |
| execute_cmd_pre_hook ((struct cmd_list_element *) cmd); |
| return (0); |
| } |
| |
| int |
| signal_stop_state (int signo) |
| { |
| return signal_stop[signo]; |
| } |
| |
| int |
| signal_print_state (int signo) |
| { |
| return signal_print[signo]; |
| } |
| |
| int |
| signal_pass_state (int signo) |
| { |
| return signal_program[signo]; |
| } |
| |
| static void |
| signal_cache_update (int signo) |
| { |
| if (signo == -1) |
| { |
| for (signo = 0; signo < (int) GDB_SIGNAL_LAST; signo++) |
| signal_cache_update (signo); |
| |
| return; |
| } |
| |
| signal_pass[signo] = (signal_stop[signo] == 0 |
| && signal_print[signo] == 0 |
| && signal_program[signo] == 1); |
| } |
| |
| int |
| signal_stop_update (int signo, int state) |
| { |
| int ret = signal_stop[signo]; |
| |
| signal_stop[signo] = state; |
| signal_cache_update (signo); |
| return ret; |
| } |
| |
| int |
| signal_print_update (int signo, int state) |
| { |
| int ret = signal_print[signo]; |
| |
| signal_print[signo] = state; |
| signal_cache_update (signo); |
| return ret; |
| } |
| |
| int |
| signal_pass_update (int signo, int state) |
| { |
| int ret = signal_program[signo]; |
| |
| signal_program[signo] = state; |
| signal_cache_update (signo); |
| return ret; |
| } |
| |
| static void |
| sig_print_header (void) |
| { |
| printf_filtered (_("Signal Stop\tPrint\tPass " |
| "to program\tDescription\n")); |
| } |
| |
| static void |
| sig_print_info (enum gdb_signal oursig) |
| { |
| const char *name = gdb_signal_to_name (oursig); |
| int name_padding = 13 - strlen (name); |
| |
| if (name_padding <= 0) |
| name_padding = 0; |
| |
| printf_filtered ("%s", name); |
| printf_filtered ("%*.*s ", name_padding, name_padding, " "); |
| printf_filtered ("%s\t", signal_stop[oursig] ? "Yes" : "No"); |
| printf_filtered ("%s\t", signal_print[oursig] ? "Yes" : "No"); |
| printf_filtered ("%s\t\t", signal_program[oursig] ? "Yes" : "No"); |
| printf_filtered ("%s\n", gdb_signal_to_string (oursig)); |
| } |
| |
| /* Specify how various signals in the inferior should be handled. */ |
| |
| static void |
| handle_command (char *args, int from_tty) |
| { |
| char **argv; |
| int digits, wordlen; |
| int sigfirst, signum, siglast; |
| enum gdb_signal oursig; |
| int allsigs; |
| int nsigs; |
| unsigned char *sigs; |
| struct cleanup *old_chain; |
| |
| if (args == NULL) |
| { |
| error_no_arg (_("signal to handle")); |
| } |
| |
| /* Allocate and zero an array of flags for which signals to handle. */ |
| |
| nsigs = (int) GDB_SIGNAL_LAST; |
| sigs = (unsigned char *) alloca (nsigs); |
| memset (sigs, 0, nsigs); |
| |
| /* Break the command line up into args. */ |
| |
| argv = gdb_buildargv (args); |
| old_chain = make_cleanup_freeargv (argv); |
| |
| /* Walk through the args, looking for signal oursigs, signal names, and |
| actions. Signal numbers and signal names may be interspersed with |
| actions, with the actions being performed for all signals cumulatively |
| specified. Signal ranges can be specified as <LOW>-<HIGH>. */ |
| |
| while (*argv != NULL) |
| { |
| wordlen = strlen (*argv); |
| for (digits = 0; isdigit ((*argv)[digits]); digits++) |
| {; |
| } |
| allsigs = 0; |
| sigfirst = siglast = -1; |
| |
| if (wordlen >= 1 && !strncmp (*argv, "all", wordlen)) |
| { |
| /* Apply action to all signals except those used by the |
| debugger. Silently skip those. */ |
| allsigs = 1; |
| sigfirst = 0; |
| siglast = nsigs - 1; |
| } |
| else if (wordlen >= 1 && !strncmp (*argv, "stop", wordlen)) |
| { |
| SET_SIGS (nsigs, sigs, signal_stop); |
| SET_SIGS (nsigs, sigs, signal_print); |
| } |
| else if (wordlen >= 1 && !strncmp (*argv, "ignore", wordlen)) |
| { |
| UNSET_SIGS (nsigs, sigs, signal_program); |
| } |
| else if (wordlen >= 2 && !strncmp (*argv, "print", wordlen)) |
| { |
| SET_SIGS (nsigs, sigs, signal_print); |
| } |
| else if (wordlen >= 2 && !strncmp (*argv, "pass", wordlen)) |
| { |
| SET_SIGS (nsigs, sigs, signal_program); |
| } |
| else if (wordlen >= 3 && !strncmp (*argv, "nostop", wordlen)) |
| { |
| UNSET_SIGS (nsigs, sigs, signal_stop); |
| } |
| else if (wordlen >= 3 && !strncmp (*argv, "noignore", wordlen)) |
| { |
| SET_SIGS (nsigs, sigs, signal_program); |
| } |
| else if (wordlen >= 4 && !strncmp (*argv, "noprint", wordlen)) |
| { |
| UNSET_SIGS (nsigs, sigs, signal_print); |
| UNSET_SIGS (nsigs, sigs, signal_stop); |
| } |
| else if (wordlen >= 4 && !strncmp (*argv, "nopass", wordlen)) |
| { |
| UNSET_SIGS (nsigs, sigs, signal_program); |
| } |
| else if (digits > 0) |
| { |
| /* It is numeric. The numeric signal refers to our own |
| internal signal numbering from target.h, not to host/target |
| signal number. This is a feature; users really should be |
| using symbolic names anyway, and the common ones like |
| SIGHUP, SIGINT, SIGALRM, etc. will work right anyway. */ |
| |
| sigfirst = siglast = (int) |
| gdb_signal_from_command (atoi (*argv)); |
| if ((*argv)[digits] == '-') |
| { |
| siglast = (int) |
| gdb_signal_from_command (atoi ((*argv) + digits + 1)); |
| } |
| if (sigfirst > siglast) |
| { |
| /* Bet he didn't figure we'd think of this case... */ |
| signum = sigfirst; |
| sigfirst = siglast; |
| siglast = signum; |
| } |
| } |
| else |
| { |
| oursig = gdb_signal_from_name (*argv); |
| if (oursig != GDB_SIGNAL_UNKNOWN) |
| { |
| sigfirst = siglast = (int) oursig; |
| } |
| else |
| { |
| /* Not a number and not a recognized flag word => complain. */ |
| error (_("Unrecognized or ambiguous flag word: \"%s\"."), *argv); |
| } |
| } |
| |
| /* If any signal numbers or symbol names were found, set flags for |
| which signals to apply actions to. */ |
| |
| for (signum = sigfirst; signum >= 0 && signum <= siglast; signum++) |
| { |
| switch ((enum gdb_signal) signum) |
| { |
| case GDB_SIGNAL_TRAP: |
| case GDB_SIGNAL_INT: |
| if (!allsigs && !sigs[signum]) |
| { |
| if (query (_("%s is used by the debugger.\n\ |
| Are you sure you want to change it? "), |
| gdb_signal_to_name ((enum gdb_signal) signum))) |
| { |
| sigs[signum] = 1; |
| } |
| else |
| { |
| printf_unfiltered (_("Not confirmed, unchanged.\n")); |
| gdb_flush (gdb_stdout); |
| } |
| } |
| break; |
| case GDB_SIGNAL_0: |
| case GDB_SIGNAL_DEFAULT: |
| case GDB_SIGNAL_UNKNOWN: |
| /* Make sure that "all" doesn't print these. */ |
| break; |
| default: |
| sigs[signum] = 1; |
| break; |
| } |
| } |
| |
| argv++; |
| } |
| |
| for (signum = 0; signum < nsigs; signum++) |
| if (sigs[signum]) |
| { |
| signal_cache_update (-1); |
| target_pass_signals ((int) GDB_SIGNAL_LAST, signal_pass); |
| target_program_signals ((int) GDB_SIGNAL_LAST, signal_program); |
| |
| if (from_tty) |
| { |
| /* Show the results. */ |
| sig_print_header (); |
| for (; signum < nsigs; signum++) |
| if (sigs[signum]) |
| sig_print_info (signum); |
| } |
| |
| break; |
| } |
| |
| do_cleanups (old_chain); |
| } |
| |
| static void |
| xdb_handle_command (char *args, int from_tty) |
| { |
| char **argv; |
| struct cleanup *old_chain; |
| |
| if (args == NULL) |
| error_no_arg (_("xdb command")); |
| |
| /* Break the command line up into args. */ |
| |
| argv = gdb_buildargv (args); |
| old_chain = make_cleanup_freeargv (argv); |
| if (argv[1] != (char *) NULL) |
| { |
| char *argBuf; |
| int bufLen; |
| |
| bufLen = strlen (argv[0]) + 20; |
| argBuf = (char *) xmalloc (bufLen); |
| if (argBuf) |
| { |
| int validFlag = 1; |
| enum gdb_signal oursig; |
| |
| oursig = gdb_signal_from_name (argv[0]); |
| memset (argBuf, 0, bufLen); |
| if (strcmp (argv[1], "Q") == 0) |
| sprintf (argBuf, "%s %s", argv[0], "noprint"); |
| else |
| { |
| if (strcmp (argv[1], "s") == 0) |
| { |
| if (!signal_stop[oursig]) |
| sprintf (argBuf, "%s %s", argv[0], "stop"); |
| else |
| sprintf (argBuf, "%s %s", argv[0], "nostop"); |
| } |
| else if (strcmp (argv[1], "i") == 0) |
| { |
| if (!signal_program[oursig]) |
| sprintf (argBuf, "%s %s", argv[0], "pass"); |
| else |
| sprintf (argBuf, "%s %s", argv[0], "nopass"); |
| } |
| else if (strcmp (argv[1], "r") == 0) |
| { |
| if (!signal_print[oursig]) |
| sprintf (argBuf, "%s %s", argv[0], "print"); |
| else |
| sprintf (argBuf, "%s %s", argv[0], "noprint"); |
| } |
| else |
| validFlag = 0; |
| } |
| if (validFlag) |
| handle_command (argBuf, from_tty); |
| else |
| printf_filtered (_("Invalid signal handling flag.\n")); |
| if (argBuf) |
| xfree (argBuf); |
| } |
| } |
| do_cleanups (old_chain); |
| } |
| |
| enum gdb_signal |
| gdb_signal_from_command (int num) |
| { |
| if (num >= 1 && num <= 15) |
| return (enum gdb_signal) num; |
| error (_("Only signals 1-15 are valid as numeric signals.\n\ |
| Use \"info signals\" for a list of symbolic signals.")); |
| } |
| |
| /* Print current contents of the tables set by the handle command. |
| It is possible we should just be printing signals actually used |
| by the current target (but for things to work right when switching |
| targets, all signals should be in the signal tables). */ |
| |
| static void |
| signals_info (char *signum_exp, int from_tty) |
| { |
| enum gdb_signal oursig; |
| |
| sig_print_header (); |
| |
| if (signum_exp) |
| { |
| /* First see if this is a symbol name. */ |
| oursig = gdb_signal_from_name (signum_exp); |
| if (oursig == GDB_SIGNAL_UNKNOWN) |
| { |
| /* No, try numeric. */ |
| oursig = |
| gdb_signal_from_command (parse_and_eval_long (signum_exp)); |
| } |
| sig_print_info (oursig); |
| return; |
| } |
| |
| printf_filtered ("\n"); |
| /* These ugly casts brought to you by the native VAX compiler. */ |
| for (oursig = GDB_SIGNAL_FIRST; |
| (int) oursig < (int) GDB_SIGNAL_LAST; |
| oursig = (enum gdb_signal) ((int) oursig + 1)) |
| { |
| QUIT; |
| |
| if (oursig != GDB_SIGNAL_UNKNOWN |
| && oursig != GDB_SIGNAL_DEFAULT && oursig != GDB_SIGNAL_0) |
| sig_print_info (oursig); |
| } |
| |
| printf_filtered (_("\nUse the \"handle\" command " |
| "to change these tables.\n")); |
| } |
| |
| /* Check if it makes sense to read $_siginfo from the current thread |
| at this point. If not, throw an error. */ |
| |
| static void |
| validate_siginfo_access (void) |
| { |
| /* No current inferior, no siginfo. */ |
| if (ptid_equal (inferior_ptid, null_ptid)) |
| error (_("No thread selected.")); |
| |
| /* Don't try to read from a dead thread. */ |
| if (is_exited (inferior_ptid)) |
| error (_("The current thread has terminated")); |
| |
| /* ... or from a spinning thread. */ |
| if (is_running (inferior_ptid)) |
| error (_("Selected thread is running.")); |
| } |
| |
| /* The $_siginfo convenience variable is a bit special. We don't know |
| for sure the type of the value until we actually have a chance to |
| fetch the data. The type can change depending on gdbarch, so it is |
| also dependent on which thread you have selected. |
| |
| 1. making $_siginfo be an internalvar that creates a new value on |
| access. |
| |
| 2. making the value of $_siginfo be an lval_computed value. */ |
| |
| /* This function implements the lval_computed support for reading a |
| $_siginfo value. */ |
| |
| static void |
| siginfo_value_read (struct value *v) |
| { |
| LONGEST transferred; |
| |
| validate_siginfo_access (); |
| |
| transferred = |
| target_read (¤t_target, TARGET_OBJECT_SIGNAL_INFO, |
| NULL, |
| value_contents_all_raw (v), |
| value_offset (v), |
| TYPE_LENGTH (value_type (v))); |
| |
| if (transferred != TYPE_LENGTH (value_type (v))) |
| error (_("Unable to read siginfo")); |
| } |
| |
| /* This function implements the lval_computed support for writing a |
| $_siginfo value. */ |
| |
| static void |
| siginfo_value_write (struct value *v, struct value *fromval) |
| { |
| LONGEST transferred; |
| |
| validate_siginfo_access (); |
| |
| transferred = target_write (¤t_target, |
| TARGET_OBJECT_SIGNAL_INFO, |
| NULL, |
| value_contents_all_raw (fromval), |
| value_offset (v), |
| TYPE_LENGTH (value_type (fromval))); |
| |
| if (transferred != TYPE_LENGTH (value_type (fromval))) |
| error (_("Unable to write siginfo")); |
| } |
| |
| static const struct lval_funcs siginfo_value_funcs = |
| { |
| siginfo_value_read, |
| siginfo_value_write |
| }; |
| |
| /* Return a new value with the correct type for the siginfo object of |
| the current thread using architecture GDBARCH. Return a void value |
| if there's no object available. */ |
| |
| static struct value * |
| siginfo_make_value (struct gdbarch *gdbarch, struct internalvar *var, |
| void *ignore) |
| { |
| if (target_has_stack |
| && !ptid_equal (inferior_ptid, null_ptid) |
| && gdbarch_get_siginfo_type_p (gdbarch)) |
| { |
| struct type *type = gdbarch_get_siginfo_type (gdbarch); |
| |
| return allocate_computed_value (type, &siginfo_value_funcs, NULL); |
| } |
| |
| return allocate_value (builtin_type (gdbarch)->builtin_void); |
| } |
| |
| |
| /* infcall_suspend_state contains state about the program itself like its |
| registers and any signal it received when it last stopped. |
| This state must be restored regardless of how the inferior function call |
| ends (either successfully, or after it hits a breakpoint or signal) |
| if the program is to properly continue where it left off. */ |
| |
| struct infcall_suspend_state |
| { |
| struct thread_suspend_state thread_suspend; |
| #if 0 /* Currently unused and empty structures are not valid C. */ |
| struct inferior_suspend_state inferior_suspend; |
| #endif |
| |
| /* Other fields: */ |
| CORE_ADDR stop_pc; |
| struct regcache *registers; |
| |
| /* Format of SIGINFO_DATA or NULL if it is not present. */ |
| struct gdbarch *siginfo_gdbarch; |
| |
| /* The inferior format depends on SIGINFO_GDBARCH and it has a length of |
| TYPE_LENGTH (gdbarch_get_siginfo_type ()). For different gdbarch the |
| content would be invalid. */ |
| gdb_byte *siginfo_data; |
| }; |
| |
| struct infcall_suspend_state * |
| save_infcall_suspend_state (void) |
| { |
| struct infcall_suspend_state *inf_state; |
| struct thread_info *tp = inferior_thread (); |
| struct inferior *inf = current_inferior (); |
| struct regcache *regcache = get_current_regcache (); |
| struct gdbarch *gdbarch = get_regcache_arch (regcache); |
| gdb_byte *siginfo_data = NULL; |
| |
| if (gdbarch_get_siginfo_type_p (gdbarch)) |
| { |
| struct type *type = gdbarch_get_siginfo_type (gdbarch); |
| size_t len = TYPE_LENGTH (type); |
| struct cleanup *back_to; |
| |
| siginfo_data = xmalloc (len); |
| back_to = make_cleanup (xfree, siginfo_data); |
| |
| if (target_read (¤t_target, TARGET_OBJECT_SIGNAL_INFO, NULL, |
| siginfo_data, 0, len) == len) |
| discard_cleanups (back_to); |
| else |
| { |
| /* Errors ignored. */ |
| do_cleanups (back_to); |
| siginfo_data = NULL; |
| } |
| } |
| |
| inf_state = XZALLOC (struct infcall_suspend_state); |
| |
| if (siginfo_data) |
| { |
| inf_state->siginfo_gdbarch = gdbarch; |
| inf_state->siginfo_data = siginfo_data; |
| } |
| |
| inf_state->thread_suspend = tp->suspend; |
| #if 0 /* Currently unused and empty structures are not valid C. */ |
| inf_state->inferior_suspend = inf->suspend; |
| #endif |
| |
| /* run_inferior_call will not use the signal due to its `proceed' call with |
| GDB_SIGNAL_0 anyway. */ |
| tp->suspend.stop_signal = GDB_SIGNAL_0; |
| |
| inf_state->stop_pc = stop_pc; |
| |
| inf_state->registers = regcache_dup (regcache); |
| |
| return inf_state; |
| } |
| |
| /* Restore inferior session state to INF_STATE. */ |
| |
| void |
| restore_infcall_suspend_state (struct infcall_suspend_state *inf_state) |
| { |
| struct thread_info *tp = inferior_thread (); |
| struct inferior *inf = current_inferior (); |
| struct regcache *regcache = get_current_regcache (); |
| struct gdbarch *gdbarch = get_regcache_arch (regcache); |
| |
| tp->suspend = inf_state->thread_suspend; |
| #if 0 /* Currently unused and empty structures are not valid C. */ |
| inf->suspend = inf_state->inferior_suspend; |
| #endif |
| |
| stop_pc = inf_state->stop_pc; |
| |
| if (inf_state->siginfo_gdbarch == gdbarch) |
| { |
| struct type *type = gdbarch_get_siginfo_type (gdbarch); |
| size_t len = TYPE_LENGTH (type); |
| |
| /* Errors ignored. */ |
| target_write (¤t_target, TARGET_OBJECT_SIGNAL_INFO, NULL, |
| inf_state->siginfo_data, 0, len); |
| } |
| |
| /* The inferior can be gone if the user types "print exit(0)" |
| (and perhaps other times). */ |
| if (target_has_execution) |
| /* NB: The register write goes through to the target. */ |
| regcache_cpy (regcache, inf_state->registers); |
| |
| discard_infcall_suspend_state (inf_state); |
| } |
| |
| static void |
| do_restore_infcall_suspend_state_cleanup (void *state) |
| { |
| restore_infcall_suspend_state (state); |
| } |
| |
| struct cleanup * |
| make_cleanup_restore_infcall_suspend_state |
| (struct infcall_suspend_state *inf_state) |
| { |
| return make_cleanup (do_restore_infcall_suspend_state_cleanup, inf_state); |
| } |
| |
| void |
| discard_infcall_suspend_state (struct infcall_suspend_state *inf_state) |
| { |
| regcache_xfree (inf_state->registers); |
| xfree (inf_state->siginfo_data); |
| xfree (inf_state); |
| } |
| |
| struct regcache * |
| get_infcall_suspend_state_regcache (struct infcall_suspend_state *inf_state) |
| { |
| return inf_state->registers; |
| } |
| |
| /* infcall_control_state contains state regarding gdb's control of the |
| inferior itself like stepping control. It also contains session state like |
| the user's currently selected frame. */ |
| |
| struct infcall_control_state |
| { |
| struct thread_control_state thread_control; |
| struct inferior_control_state inferior_control; |
| |
| /* Other fields: */ |
| enum stop_stack_kind stop_stack_dummy; |
| int stopped_by_random_signal; |
| int stop_after_trap; |
| |
| /* ID if the selected frame when the inferior function call was made. */ |
| struct frame_id selected_frame_id; |
| }; |
| |
| /* Save all of the information associated with the inferior<==>gdb |
| connection. */ |
| |
| struct infcall_control_state * |
| save_infcall_control_state (void) |
| { |
| struct infcall_control_state *inf_status = xmalloc (sizeof (*inf_status)); |
| struct thread_info *tp = inferior_thread (); |
| struct inferior *inf = current_inferior (); |
| |
| inf_status->thread_control = tp->control; |
| inf_status->inferior_control = inf->control; |
| |
| tp->control.step_resume_breakpoint = NULL; |
| tp->control.exception_resume_breakpoint = NULL; |
| |
| /* Save original bpstat chain to INF_STATUS; replace it in TP with copy of |
| chain. If caller's caller is walking the chain, they'll be happier if we |
| hand them back the original chain when restore_infcall_control_state is |
| called. */ |
| tp->control.stop_bpstat = bpstat_copy (tp->control.stop_bpstat); |
| |
| /* Other fields: */ |
| inf_status->stop_stack_dummy = stop_stack_dummy; |
| inf_status->stopped_by_random_signal = stopped_by_random_signal; |
| inf_status->stop_after_trap = stop_after_trap; |
| |
| inf_status->selected_frame_id = get_frame_id (get_selected_frame (NULL)); |
| |
| return inf_status; |
| } |
| |
| static int |
| restore_selected_frame (void *args) |
| { |
| struct frame_id *fid = (struct frame_id *) args; |
| struct frame_info *frame; |
| |
| frame = frame_find_by_id (*fid); |
| |
| /* If inf_status->selected_frame_id is NULL, there was no previously |
| selected frame. */ |
| if (frame == NULL) |
| { |
| warning (_("Unable to restore previously selected frame.")); |
| return 0; |
| } |
| |
| select_frame (frame); |
| |
| return (1); |
| } |
| |
| /* Restore inferior session state to INF_STATUS. */ |
| |
| void |
| restore_infcall_control_state (struct infcall_control_state *inf_status) |
| { |
| struct thread_info *tp = inferior_thread (); |
| struct inferior *inf = current_inferior (); |
| |
| if (tp->control.step_resume_breakpoint) |
| tp->control.step_resume_breakpoint->disposition = disp_del_at_next_stop; |
| |
| if (tp->control.exception_resume_breakpoint) |
| tp->control.exception_resume_breakpoint->disposition |
| = disp_del_at_next_stop; |
| |
| /* Handle the bpstat_copy of the chain. */ |
| bpstat_clear (&tp->control.stop_bpstat); |
| |
| tp->control = inf_status->thread_control; |
| inf->control = inf_status->inferior_control; |
| |
| /* Other fields: */ |
| stop_stack_dummy = inf_status->stop_stack_dummy; |
| stopped_by_random_signal = inf_status->stopped_by_random_signal; |
| stop_after_trap = inf_status->stop_after_trap; |
| |
| if (target_has_stack) |
| { |
| /* The point of catch_errors is that if the stack is clobbered, |
| walking the stack might encounter a garbage pointer and |
| error() trying to dereference it. */ |
| if (catch_errors |
| (restore_selected_frame, &inf_status->selected_frame_id, |
| "Unable to restore previously selected frame:\n", |
| RETURN_MASK_ERROR) == 0) |
| /* Error in restoring the selected frame. Select the innermost |
| frame. */ |
| select_frame (get_current_frame ()); |
| } |
| |
| xfree (inf_status); |
| } |
| |
| static void |
| do_restore_infcall_control_state_cleanup (void *sts) |
| { |
| restore_infcall_control_state (sts); |
| } |
| |
| struct cleanup * |
| make_cleanup_restore_infcall_control_state |
| (struct infcall_control_state *inf_status) |
| { |
| return make_cleanup (do_restore_infcall_control_state_cleanup, inf_status); |
| } |
| |
| void |
| discard_infcall_control_state (struct infcall_control_state *inf_status) |
| { |
| if (inf_status->thread_control.step_resume_breakpoint) |
| inf_status->thread_control.step_resume_breakpoint->disposition |
| = disp_del_at_next_stop; |
| |
| if (inf_status->thread_control.exception_resume_breakpoint) |
| inf_status->thread_control.exception_resume_breakpoint->disposition |
| = disp_del_at_next_stop; |
| |
| /* See save_infcall_control_state for info on stop_bpstat. */ |
| bpstat_clear (&inf_status->thread_control.stop_bpstat); |
| |
| xfree (inf_status); |
| } |
| |
| int |
| ptid_match (ptid_t ptid, ptid_t filter) |
| { |
| if (ptid_equal (filter, minus_one_ptid)) |
| return 1; |
| if (ptid_is_pid (filter) |
| && ptid_get_pid (ptid) == ptid_get_pid (filter)) |
| return 1; |
| else if (ptid_equal (ptid, filter)) |
| return 1; |
| |
| return 0; |
| } |
| |
| /* restore_inferior_ptid() will be used by the cleanup machinery |
| to restore the inferior_ptid value saved in a call to |
| save_inferior_ptid(). */ |
| |
| static void |
| restore_inferior_ptid (void *arg) |
| { |
| ptid_t *saved_ptid_ptr = arg; |
| |
| inferior_ptid = *saved_ptid_ptr; |
| xfree (arg); |
| } |
| |
| /* Save the value of inferior_ptid 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_inferior_ptid (void) |
| { |
| ptid_t *saved_ptid_ptr; |
| |
| saved_ptid_ptr = xmalloc (sizeof (ptid_t)); |
| *saved_ptid_ptr = inferior_ptid; |
| return make_cleanup (restore_inferior_ptid, saved_ptid_ptr); |
| } |
| |
| |
| /* User interface for reverse debugging: |
| Set exec-direction / show exec-direction commands |
| (returns error unless target implements to_set_exec_direction method). */ |
| |
| int execution_direction = EXEC_FORWARD; |
| static const char exec_forward[] = "forward"; |
| static const char exec_reverse[] = "reverse"; |
| static const char *exec_direction = exec_forward; |
| static const char *const exec_direction_names[] = { |
| exec_forward, |
| exec_reverse, |
| NULL |
| }; |
| |
| static void |
| set_exec_direction_func (char *args, int from_tty, |
| struct cmd_list_element *cmd) |
| { |
| if (target_can_execute_reverse) |
| { |
| if (!strcmp (exec_direction, exec_forward)) |
| execution_direction = EXEC_FORWARD; |
| else if (!strcmp (exec_direction, exec_reverse)) |
| execution_direction = EXEC_REVERSE; |
| } |
| else |
| { |
| exec_direction = exec_forward; |
| error (_("Target does not support this operation.")); |
| } |
| } |
| |
| static void |
| show_exec_direction_func (struct ui_file *out, int from_tty, |
| struct cmd_list_element *cmd, const char *value) |
| { |
| switch (execution_direction) { |
| case EXEC_FORWARD: |
| fprintf_filtered (out, _("Forward.\n")); |
| break; |
| case EXEC_REVERSE: |
| fprintf_filtered (out, _("Reverse.\n")); |
| break; |
| default: |
| internal_error (__FILE__, __LINE__, |
| _("bogus execution_direction value: %d"), |
| (int) execution_direction); |
| } |
| } |
| |
| /* User interface for non-stop mode. */ |
| |
| int non_stop = 0; |
| |
| static void |
| set_non_stop (char *args, int from_tty, |
| struct cmd_list_element *c) |
| { |
| if (target_has_execution) |
| { |
| non_stop_1 = non_stop; |
| error (_("Cannot change this setting while the inferior is running.")); |
| } |
| |
| non_stop = non_stop_1; |
| } |
| |
| static void |
| show_non_stop (struct ui_file *file, int from_tty, |
| struct cmd_list_element *c, const char *value) |
| { |
| fprintf_filtered (file, |
| _("Controlling the inferior in non-stop mode is %s.\n"), |
| value); |
| } |
| |
| static void |
| show_schedule_multiple (struct ui_file *file, int from_tty, |
| struct cmd_list_element *c, const char *value) |
| { |
| fprintf_filtered (file, _("Resuming the execution of threads " |
| "of all processes is %s.\n"), value); |
| } |
| |
| /* Implementation of `siginfo' variable. */ |
| |
| static const struct internalvar_funcs siginfo_funcs = |
| { |
| siginfo_make_value, |
| NULL, |
| NULL |
| }; |
| |
| void |
| _initialize_infrun (void) |
| { |
| int i; |
| int numsigs; |
| |
| add_info ("signals", signals_info, _("\ |
| What debugger does when program gets various signals.\n\ |
| Specify a signal as argument to print info on that signal only.")); |
| add_info_alias ("handle", "signals", 0); |
| |
| add_com ("handle", class_run, handle_command, _("\ |
| Specify how to handle a signal.\n\ |
| Args are signals and actions to apply to those signals.\n\ |
| Symbolic signals (e.g. SIGSEGV) are recommended but numeric signals\n\ |
| from 1-15 are allowed for compatibility with old versions of GDB.\n\ |
| Numeric ranges may be specified with the form LOW-HIGH (e.g. 1-5).\n\ |
| The special arg \"all\" is recognized to mean all signals except those\n\ |
| used by the debugger, typically SIGTRAP and SIGINT.\n\ |
| Recognized actions include \"stop\", \"nostop\", \"print\", \"noprint\",\n\ |
| \"pass\", \"nopass\", \"ignore\", or \"noignore\".\n\ |
| Stop means reenter debugger if this signal happens (implies print).\n\ |
| Print means print a message if this signal happens.\n\ |
| Pass means let program see this signal; otherwise program doesn't know.\n\ |
| Ignore is a synonym for nopass and noignore is a synonym for pass.\n\ |
| Pass and Stop may be combined.")); |
| if (xdb_commands) |
| { |
| add_com ("lz", class_info, signals_info, _("\ |
| What debugger does when program gets various signals.\n\ |
| Specify a signal as argument to print info on that signal only.")); |
| add_com ("z", class_run, xdb_handle_command, _("\ |
| Specify how to handle a signal.\n\ |
| Args are signals and actions to apply to those signals.\n\ |
| Symbolic signals (e.g. SIGSEGV) are recommended but numeric signals\n\ |
| from 1-15 are allowed for compatibility with old versions of GDB.\n\ |
| Numeric ranges may be specified with the form LOW-HIGH (e.g. 1-5).\n\ |
| The special arg \"all\" is recognized to mean all signals except those\n\ |
| used by the debugger, typically SIGTRAP and SIGINT.\n\ |
| Recognized actions include \"s\" (toggles between stop and nostop),\n\ |
| \"r\" (toggles between print and noprint), \"i\" (toggles between pass and \ |
| nopass), \"Q\" (noprint)\n\ |
| Stop means reenter debugger if this signal happens (implies print).\n\ |
| Print means print a message if this signal happens.\n\ |
| Pass means let program see this signal; otherwise program doesn't know.\n\ |
| Ignore is a synonym for nopass and noignore is a synonym for pass.\n\ |
| Pass and Stop may be combined.")); |
| } |
| |
| if (!dbx_commands) |
| stop_command = add_cmd ("stop", class_obscure, |
| not_just_help_class_command, _("\ |
| There is no `stop' command, but you can set a hook on `stop'.\n\ |
| This allows you to set a list of commands to be run each time execution\n\ |
| of the program stops."), &cmdlist); |
| |
| add_setshow_zinteger_cmd ("infrun", class_maintenance, &debug_infrun, _("\ |
| Set inferior debugging."), _("\ |
| Show inferior debugging."), _("\ |
| When non-zero, inferior specific debugging is enabled."), |
| NULL, |
| show_debug_infrun, |
| &setdebuglist, &showdebuglist); |
| |
| add_setshow_boolean_cmd ("displaced", class_maintenance, |
| &debug_displaced, _("\ |
| Set displaced stepping debugging."), _("\ |
| Show displaced stepping debugging."), _("\ |
| When non-zero, displaced stepping specific debugging is enabled."), |
| NULL, |
| show_debug_displaced, |
| &setdebuglist, &showdebuglist); |
| |
| add_setshow_boolean_cmd ("non-stop", no_class, |
| &non_stop_1, _("\ |
| Set whether gdb controls the inferior in non-stop mode."), _("\ |
| Show whether gdb controls the inferior in non-stop mode."), _("\ |
| When debugging a multi-threaded program and this setting is\n\ |
| off (the default, also called all-stop mode), when one thread stops\n\ |
| (for a breakpoint, watchpoint, exception, or similar events), GDB stops\n\ |
| all other threads in the program while you interact with the thread of\n\ |
| interest. When you continue or step a thread, you can allow the other\n\ |
| threads to run, or have them remain stopped, but while you inspect any\n\ |
| thread's state, all threads stop.\n\ |
| \n\ |
| In non-stop mode, when one thread stops, other threads can continue\n\ |
| to run freely. You'll be able to step each thread independently,\n\ |
| leave it stopped or free to run as needed."), |
| set_non_stop, |
| show_non_stop, |
| &setlist, |
| &showlist); |
| |
| numsigs = (int) GDB_SIGNAL_LAST; |
| signal_stop = (unsigned char *) xmalloc (sizeof (signal_stop[0]) * numsigs); |
| signal_print = (unsigned char *) |
| xmalloc (sizeof (signal_print[0]) * numsigs); |
| signal_program = (unsigned char *) |
| xmalloc (sizeof (signal_program[0]) * numsigs); |
| signal_pass = (unsigned char *) |
| xmalloc (sizeof (signal_program[0]) * numsigs); |
| for (i = 0; i < numsigs; i++) |
| { |
| signal_stop[i] = 1; |
| signal_print[i] = 1; |
| signal_program[i] = 1; |
| } |
| |
| /* Signals caused by debugger's own actions |
| should not be given to the program afterwards. */ |
| signal_program[GDB_SIGNAL_TRAP] = 0; |
| signal_program[GDB_SIGNAL_INT] = 0; |
| |
| /* Signals that are not errors should not normally enter the debugger. */ |
| signal_stop[GDB_SIGNAL_ALRM] = 0; |
| signal_print[GDB_SIGNAL_ALRM] = 0; |
| signal_stop[GDB_SIGNAL_VTALRM] = 0; |
| signal_print[GDB_SIGNAL_VTALRM] = 0; |
| signal_stop[GDB_SIGNAL_PROF] = 0; |
| signal_print[GDB_SIGNAL_PROF] = 0; |
| signal_stop[GDB_SIGNAL_CHLD] = 0; |
| signal_print[GDB_SIGNAL_CHLD] = 0; |
| signal_stop[GDB_SIGNAL_IO] = 0; |
| signal_print[GDB_SIGNAL_IO] = 0; |
| signal_stop[GDB_SIGNAL_POLL] = 0; |
| signal_print[GDB_SIGNAL_POLL] = 0; |
| signal_stop[GDB_SIGNAL_URG] = 0; |
| signal_print[GDB_SIGNAL_URG] = 0; |
| signal_stop[GDB_SIGNAL_WINCH] = 0; |
| signal_print[GDB_SIGNAL_WINCH] = 0; |
| signal_stop[GDB_SIGNAL_PRIO] = 0; |
| signal_print[GDB_SIGNAL_PRIO] = 0; |
| |
| /* These signals are used internally by user-level thread |
| implementations. (See signal(5) on Solaris.) Like the above |
| signals, a healthy program receives and handles them as part of |
| its normal operation. */ |
| signal_stop[GDB_SIGNAL_LWP] = 0; |
| signal_print[GDB_SIGNAL_LWP] = 0; |
| signal_stop[GDB_SIGNAL_WAITING] = 0; |
| signal_print[GDB_SIGNAL_WAITING] = 0; |
| signal_stop[GDB_SIGNAL_CANCEL] = 0; |
| signal_print[GDB_SIGNAL_CANCEL] = 0; |
| |
| /* Update cached state. */ |
| signal_cache_update (-1); |
| |
| add_setshow_zinteger_cmd ("stop-on-solib-events", class_support, |
| &stop_on_solib_events, _("\ |
| Set stopping for shared library events."), _("\ |
| Show stopping for shared library events."), _("\ |
| If nonzero, gdb will give control to the user when the dynamic linker\n\ |
| notifies gdb of shared library events. The most common event of interest\n\ |
| to the user would be loading/unloading of a new library."), |
| NULL, |
| show_stop_on_solib_events, |
| &setlist, &showlist); |
| |
| add_setshow_enum_cmd ("follow-fork-mode", class_run, |
| follow_fork_mode_kind_names, |
| &follow_fork_mode_string, _("\ |
| Set debugger response to a program call of fork or vfork."), _("\ |
| Show debugger response to a program call of fork or vfork."), _("\ |
| A fork or vfork creates a new process. follow-fork-mode can be:\n\ |
| parent - the original process is debugged after a fork\n\ |
| child - the new process is debugged after a fork\n\ |
| The unfollowed process will continue to run.\n\ |
| By default, the debugger will follow the parent process."), |
| NULL, |
| show_follow_fork_mode_string, |
| &setlist, &showlist); |
| |
| add_setshow_enum_cmd ("follow-exec-mode", class_run, |
| follow_exec_mode_names, |
| &follow_exec_mode_string, _("\ |
| Set debugger response to a program call of exec."), _("\ |
| Show debugger response to a program call of exec."), _("\ |
| An exec call replaces the program image of a process.\n\ |
| \n\ |
| follow-exec-mode can be:\n\ |
| \n\ |
| new - the debugger creates a new inferior and rebinds the process\n\ |
| to this new inferior. The program the process was running before\n\ |
| the exec call can be restarted afterwards by restarting the original\n\ |
| inferior.\n\ |
| \n\ |
| same - the debugger keeps the process bound to the same inferior.\n\ |
| The new executable image replaces the previous executable loaded in\n\ |
| the inferior. Restarting the inferior after the exec call restarts\n\ |
| the executable the process was running after the exec call.\n\ |
| \n\ |
| By default, the debugger will use the same inferior."), |
| NULL, |
| show_follow_exec_mode_string, |
| &setlist, &showlist); |
| |
| add_setshow_enum_cmd ("scheduler-locking", class_run, |
| scheduler_enums, &scheduler_mode, _("\ |
| Set mode for locking scheduler during execution."), _("\ |
| Show mode for locking scheduler during execution."), _("\ |
| off == no locking (threads may preempt at any time)\n\ |
| on == full locking (no thread except the current thread may run)\n\ |
| step == scheduler locked during every single-step operation.\n\ |
| In this mode, no other thread may run during a step command.\n\ |
| Other threads may run while stepping over a function call ('next')."), |
| set_schedlock_func, /* traps on target vector */ |
| show_scheduler_mode, |
| &setlist, &showlist); |
| |
| add_setshow_boolean_cmd ("schedule-multiple", class_run, &sched_multi, _("\ |
| Set mode for resuming threads of all processes."), _("\ |
| Show mode for resuming threads of all processes."), _("\ |
| When on, execution commands (such as 'continue' or 'next') resume all\n\ |
| threads of all processes. When off (which is the default), execution\n\ |
| commands only resume the threads of the current process. The set of\n\ |
| threads that are resumed is further refined by the scheduler-locking\n\ |
| mode (see help set scheduler-locking)."), |
| NULL, |
| show_schedule_multiple, |
| &setlist, &showlist); |
| |
| add_setshow_boolean_cmd ("step-mode", class_run, &step_stop_if_no_debug, _("\ |
| Set mode of the step operation."), _("\ |
| Show mode of the step operation."), _("\ |
| When set, doing a step over a function without debug line information\n\ |
| will stop at the first instruction of that function. Otherwise, the\n\ |
| function is skipped and the step command stops at a different source line."), |
| NULL, |
| show_step_stop_if_no_debug, |
| &setlist, &showlist); |
| |
| add_setshow_auto_boolean_cmd ("displaced-stepping", class_run, |
| &can_use_displaced_stepping, _("\ |
| Set debugger's willingness to use displaced stepping."), _("\ |
| Show debugger's willingness to use displaced stepping."), _("\ |
| If on, gdb will use displaced stepping to step over breakpoints if it is\n\ |
| supported by the target architecture. If off, gdb will not use displaced\n\ |
| stepping to step over breakpoints, even if such is supported by the target\n\ |
| architecture. If auto (which is the default), gdb will use displaced stepping\n\ |
| if the target architecture supports it and non-stop mode is active, but will not\n\ |
| use it in all-stop mode (see help set non-stop)."), |
| NULL, |
| show_can_use_displaced_stepping, |
| &setlist, &showlist); |
| |
| add_setshow_enum_cmd ("exec-direction", class_run, exec_direction_names, |
| &exec_direction, _("Set direction of execution.\n\ |
| Options are 'forward' or 'reverse'."), |
| _("Show direction of execution (forward/reverse)."), |
| _("Tells gdb whether to execute forward or backward."), |
| set_exec_direction_func, show_exec_direction_func, |
| &setlist, &showlist); |
| |
| /* Set/show detach-on-fork: user-settable mode. */ |
| |
| add_setshow_boolean_cmd ("detach-on-fork", class_run, &detach_fork, _("\ |
| Set whether gdb will detach the child of a fork."), _("\ |
| Show whether gdb will detach the child of a fork."), _("\ |
| Tells gdb whether to detach the child of a fork."), |
| NULL, NULL, &setlist, &showlist); |
| |
| /* Set/show disable address space randomization mode. */ |
| |
| add_setshow_boolean_cmd ("disable-randomization", class_support, |
| &disable_randomization, _("\ |
| Set disabling of debuggee's virtual address space randomization."), _("\ |
| Show disabling of debuggee's virtual address space randomization."), _("\ |
| When this mode is on (which is the default), randomization of the virtual\n\ |
| address space is disabled. Standalone programs run with the randomization\n\ |
| enabled by default on some platforms."), |
| &set_disable_randomization, |
| &show_disable_randomization, |
| &setlist, &showlist); |
| |
| /* ptid initializations */ |
| inferior_ptid = null_ptid; |
| target_last_wait_ptid = minus_one_ptid; |
| |
| observer_attach_thread_ptid_changed (infrun_thread_ptid_changed); |
| observer_attach_thread_stop_requested (infrun_thread_stop_requested); |
| observer_attach_thread_exit (infrun_thread_thread_exit); |
| observer_attach_inferior_exit (infrun_inferior_exit); |
| |
| /* Explicitly create without lookup, since that tries to create a |
| value with a void typed value, and when we get here, gdbarch |
| isn't initialized yet. At this point, we're quite sure there |
| isn't another convenience variable of the same name. */ |
| create_internalvar_type_lazy ("_siginfo", &siginfo_funcs, NULL); |
| |
| add_setshow_boolean_cmd ("observer", no_class, |
| &observer_mode_1, _("\ |
| Set whether gdb controls the inferior in observer mode."), _("\ |
| Show whether gdb controls the inferior in observer mode."), _("\ |
| In observer mode, GDB can get data from the inferior, but not\n\ |
| affect its execution. Registers and memory may not be changed,\n\ |
| breakpoints may not be set, and the program cannot be interrupted\n\ |
| or signalled."), |
| set_observer_mode, |
| show_observer_mode, |
| &setlist, |
| &showlist); |
| } |