/* Target-struct-independent code to start (run) and stop an inferior
process.
- Copyright (C) 1986-2013 Free Software Foundation, Inc.
+ Copyright (C) 1986-2014 Free Software Foundation, Inc.
This file is part of GDB.
along with this program. If not, see <http://www.gnu.org/licenses/>. */
#include "defs.h"
-#include "gdb_string.h"
+#include <string.h>
#include <ctype.h>
#include "symtab.h"
#include "frame.h"
#include "objfiles.h"
#include "completer.h"
#include "target-descriptions.h"
+#include "target-dcache.h"
/* Prototypes for local functions */
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);
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. */
+/* proceed 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;
+/* If set (default for legacy reasons), when following a fork, GDB
+ will detach from one of the fork branches, child or parent.
+ Exactly which branch is detached depends on 'set follow-fork-mode'
+ setting. */
+
+static int detach_fork = 1;
int debug_displaced = 0;
static void
"this platform."));
}
+/* User interface for non-stop mode. */
+
+int non_stop = 0;
+static int non_stop_1 = 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;
+}
-/* 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 gdbarch_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.
-
- The in_dynsym_resolve_code hook of the target_so_ops vector can
- generally be implemented in a pretty portable way, by comparing the
- PC against the address ranges of the dynamic linker's sections.
-
- The gdbarch_skip_solib_resolver implementation 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.
- gdbarch_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 signaling an
- error, which will obscure the change in the inferior's state. */
+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);
+}
/* "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;
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;
/* Tell the target to do whatever is necessary to follow
either parent or child. */
- if (target_follow_fork (follow_child))
+ if (target_follow_fork (follow_child, detach_fork))
{
/* Target refused to follow, or there's some other reason
we shouldn't resume. */
/* 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;
+/* Info about an instruction that is being stepped over. Invalid if
+ ASPACE is NULL. */
+
+struct step_over_info
+{
+ /* The instruction's address space. */
+ struct address_space *aspace;
+
+ /* The instruction's address. */
+ CORE_ADDR address;
+};
+
+/* The step-over info of the location that is being stepped over.
+
+ Note that with async/breakpoint always-inserted mode, a user might
+ set a new breakpoint/watchpoint/etc. exactly while a breakpoint is
+ being stepped over. As setting a new breakpoint inserts all
+ breakpoints, we need to make sure the breakpoint being stepped over
+ isn't inserted then. We do that by only clearing the step-over
+ info when the step-over is actually finished (or aborted).
+
+ Presently GDB can only step over one breakpoint at any given time.
+ Given threads that can't run code in the same address space as the
+ breakpoint's can't really miss the breakpoint, GDB could be taught
+ to step-over at most one breakpoint per address space (so this info
+ could move to the address space object if/when GDB is extended).
+ The set of breakpoints being stepped over will normally be much
+ smaller than the set of all breakpoints, so a flag in the
+ breakpoint location structure would be wasteful. A separate list
+ also saves complexity and run-time, as otherwise we'd have to go
+ through all breakpoint locations clearing their flag whenever we
+ start a new sequence. Similar considerations weigh against storing
+ this info in the thread object. Plus, not all step overs actually
+ have breakpoint locations -- e.g., stepping past a single-step
+ breakpoint, or stepping to complete a non-continuable
+ watchpoint. */
+static struct step_over_info step_over_info;
+
+/* Record the address of the breakpoint/instruction we're currently
+ stepping over. */
+
+static void
+set_step_over_info (struct address_space *aspace, CORE_ADDR address)
+{
+ step_over_info.aspace = aspace;
+ step_over_info.address = address;
+}
+
+/* Called when we're not longer stepping over a breakpoint / an
+ instruction, so all breakpoints are free to be (re)inserted. */
+
+static void
+clear_step_over_info (void)
+{
+ step_over_info.aspace = NULL;
+ step_over_info.address = 0;
+}
+
+/* See inferior.h. */
-/* 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.
+int
+stepping_past_instruction_at (struct address_space *aspace,
+ CORE_ADDR address)
+{
+ return (step_over_info.aspace != NULL
+ && breakpoint_address_match (aspace, address,
+ step_over_info.aspace,
+ step_over_info.address));
+}
- 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;
\f
/* Displaced stepping. */
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);
+ && find_record_target () == NULL);
}
/* Clean out any stray displaced stepping state. */
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 (debug_infrun)
fprintf_unfiltered (gdb_stdlog,
- "infrun: resume (step=%d, signal=%d), "
+ "infrun: resume (step=%d, signal=%s), "
"trap_expected=%d, current thread [%s] at %s\n",
- step, sig, tp->control.trap_expected,
+ step, gdb_signal_to_symbol_string (sig),
+ tp->control.trap_expected,
target_pid_to_str (inferior_ptid),
paddress (gdbarch, pc));
remove_single_step_breakpoints ();
singlestep_breakpoints_inserted_p = 0;
- insert_breakpoints ();
+ clear_step_over_info ();
tp->control.trap_expected = 0;
+
+ insert_breakpoints ();
}
if (should_resume)
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)
+ 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. */
+ breakpoint if allowed to run. */
resume_ptid = inferior_ptid;
}
stop_after_trap = 0;
+ clear_step_over_info ();
+
observer_notify_about_to_proceed ();
if (stop_registers)
}
}
-/* 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. */
+/* Returns true if TP is still stopped at a breakpoint that needs
+ stepping-over in order to make progress. If the breakpoint is gone
+ meanwhile, we can skip the whole step-over dance. */
static int
-prepare_to_proceed (int step)
+thread_still_needs_step_over (struct thread_info *tp)
+{
+ if (tp->stepping_over_breakpoint)
+ {
+ struct regcache *regcache = get_thread_regcache (tp->ptid);
+
+ if (breakpoint_here_p (get_regcache_aspace (regcache),
+ regcache_read_pc (regcache)))
+ return 1;
+
+ tp->stepping_over_breakpoint = 0;
+ }
+
+ return 0;
+}
+
+/* Look a thread other than EXCEPT that has previously reported a
+ breakpoint event, and thus needs a step-over in order to make
+ progress. Returns NULL is none is found. STEP indicates whether
+ we're about to step the current thread, in order to decide whether
+ "set scheduler-locking step" applies. */
+
+static struct thread_info *
+find_thread_needs_step_over (int step, struct thread_info *except)
{
- ptid_t wait_ptid;
- struct target_waitstatus wait_status;
int schedlock_enabled;
+ struct thread_info *tp, *current;
/* 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;
+ current = inferior_thread ();
- /* Switched over from WAIT_PID. */
- if (!ptid_equal (wait_ptid, minus_one_ptid)
- && !ptid_equal (inferior_ptid, wait_ptid))
+ /* If scheduler locking applies, we can avoid iterating over all
+ threads. */
+ if (schedlock_enabled)
{
- 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;
+ if (except != current
+ && thread_still_needs_step_over (current))
+ return current;
- /* Switch back to WAIT_PID thread. */
- switch_to_thread (wait_ptid);
+ return NULL;
+ }
- if (debug_infrun)
- fprintf_unfiltered (gdb_stdlog,
- "infrun: prepare_to_proceed (step=%d), "
- "switched to [%s]\n",
- step, target_pid_to_str (inferior_ptid));
+ ALL_THREADS (tp)
+ {
+ /* Ignore the EXCEPT thread. */
+ if (tp == except)
+ continue;
+ /* Ignore threads of processes we're not resuming. */
+ if (!sched_multi
+ && ptid_get_pid (tp->ptid) != ptid_get_pid (inferior_ptid))
+ continue;
- /* 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;
- }
+ if (thread_still_needs_step_over (tp))
+ return tp;
}
- return 0;
+ return NULL;
}
/* Basic routine for continuing the program in various fashions.
struct thread_info *tp;
CORE_ADDR pc;
struct address_space *aspace;
- /* GDB may force the inferior to step due to various reasons. */
- int force_step = 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
gdbarch = get_regcache_arch (regcache);
aspace = get_regcache_aspace (regcache);
pc = regcache_read_pc (regcache);
+ tp = inferior_thread ();
if (step > 0)
step_start_function = find_pc_function (pc);
if (step < 0)
stop_after_trap = 1;
+ /* Fill in with reasonable starting values. */
+ init_thread_stepping_state (tp);
+
if (addr == (CORE_ADDR) -1)
{
if (pc == stop_pc && breakpoint_here_p (aspace, pc)
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. */
-
- force_step = 1;
+ tp->stepping_over_breakpoint = 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. */
- force_step = 1;
+ tp->stepping_over_breakpoint = 1;
}
else
{
if (debug_infrun)
fprintf_unfiltered (gdb_stdlog,
- "infrun: proceed (addr=%s, signal=%d, step=%d)\n",
- paddress (gdbarch, addr), siggnal, step);
+ "infrun: proceed (addr=%s, signal=%s, step=%d)\n",
+ paddress (gdbarch, addr),
+ gdb_signal_to_symbol_string (siggnal), step);
if (non_stop)
/* In non-stop, each thread is handled individually. The context
;
else
{
+ struct thread_info *step_over;
+
/* In a multi-threaded task we may select another thread and
then continue or step.
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))
- force_step = 1;
+ Look for a thread other than the current (TP) that reported a
+ breakpoint hit and hasn't been resumed yet since. */
+ step_over = find_thread_needs_step_over (step, tp);
+ if (step_over != NULL)
+ {
+ if (debug_infrun)
+ fprintf_unfiltered (gdb_stdlog,
+ "infrun: need to step-over [%s] first\n",
+ target_pid_to_str (step_over->ptid));
+
+ /* Store the prev_pc for the stepping thread too, needed by
+ switch_back_to_stepping thread. */
+ tp->prev_pc = regcache_read_pc (get_current_regcache ());
+ switch_to_thread (step_over->ptid);
+ tp = step_over;
+ }
}
- /* prepare_to_proceed may change the current thread. */
- tp = inferior_thread ();
-
- if (force_step)
+ /* If we need to step over a breakpoint, and we're not using
+ displaced stepping to do so, insert all breakpoints (watchpoints,
+ etc.) but the one we're stepping over, step one instruction, and
+ then re-insert the breakpoint when that step is finished. */
+ if (tp->stepping_over_breakpoint && !use_displaced_stepping (gdbarch))
{
- 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 ();
+ struct regcache *regcache = get_current_regcache ();
+
+ set_step_over_info (get_regcache_aspace (regcache),
+ regcache_read_pc (regcache));
}
+ else
+ clear_step_over_info ();
+
+ insert_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 ();
+ tp->control.trap_expected = tp->stepping_over_breakpoint;
if (!non_stop)
{
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 (force_step || step || bpstat_should_step (),
+ resume (tp->control.trap_expected || step || bpstat_should_step (),
tp->suspend.stop_signal);
/* Wait for it to stop (if not standalone)
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;
/* Discard any skipped inlined frames. */
clear_inline_frame_state (minus_one_ptid);
+
+ singlestep_ptid = null_ptid;
+ singlestep_pc = 0;
}
\f
enum infwait_states
{
infwait_normal_state,
- infwait_thread_hop_state,
infwait_step_watch_state,
infwait_nonstep_watch_state
};
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;
+
+ /* We were in infwait_step_watch_state or
+ infwait_nonstep_watch_state state, and the thread reported an
+ event. */
+ int stepped_after_stopped_by_watchpoint;
+
+ /* True if the event thread hit the single-step breakpoint of
+ another thread. Thus the event doesn't cause a stop, the thread
+ needs to be single-stepped past the single-step breakpoint before
+ we can switch back to the original stepping thread. */
+ int hit_singlestep_breakpoint;
};
static void handle_inferior_event (struct execution_control_state *ecs);
struct execution_control_state *ecs);
static void handle_step_into_function_backward (struct gdbarch *gdbarch,
struct execution_control_state *ecs);
+static void handle_signal_stop (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);
+static void process_event_stop_test (struct execution_control_state *ecs);
+static int switch_back_to_stepped_thread (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
old_chain = make_cleanup_restore_current_thread ();
+ overlay_cache_invalid = 1;
+ /* Flush target cache before starting to handle each event.
+ Target was running and cache could be stale. This is just a
+ heuristic. Running threads may modify target memory, but we
+ don't get any event. */
+ target_dcache_invalidate ();
+
/* Go through handle_inferior_event/normal_stop, so we always
have consistent output as if the stop event had been
reported. */
is set. */
fprintf_unfiltered (tmp_stream,
- "infrun: target_wait (%d", PIDGET (waiton_ptid));
- if (PIDGET (waiton_ptid) != -1)
+ "infrun: target_wait (%d", ptid_get_pid (waiton_ptid));
+ if (ptid_get_pid (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));
+ ptid_get_pid (result_ptid),
+ target_pid_to_str (result_ptid));
fprintf_unfiltered (tmp_stream,
"infrun: %s\n",
status_string);
memset (ecs, 0, sizeof (*ecs));
overlay_cache_invalid = 1;
+ /* Flush target cache before starting to handle each event.
+ Target was running and cache could be stale. This is just a
+ heuristic. Running threads may modify target memory, but we
+ don't get any event. */
+ target_dcache_invalidate ();
if (deprecated_target_wait_hook)
ecs->ptid = deprecated_target_wait_hook (pid_ptid, &ecs->ws, 0);
overlay_cache_invalid = 1;
+ /* Flush target cache before starting to handle each event.
+ Target was running and cache could be stale. This is just a
+ heuristic. Running threads may modify target memory, but we
+ don't get any event. */
+ target_dcache_invalidate ();
+
if (deprecated_target_wait_hook)
ecs->ptid = deprecated_target_wait_hook (waiton_ptid, &ecs->ws, 0);
else
make_cleanup_restore_current_thread ();
overlay_cache_invalid = 1;
+ /* Flush target cache before starting to handle each event. Target
+ was running and cache could be stale. This is just a heuristic.
+ Running threads may modify target memory, but we don't get any
+ event. */
+ target_dcache_invalidate ();
make_cleanup_restore_integer (&execution_direction);
execution_direction = target_execution_direction ();
tss->step_after_step_resume_breakpoint = 0;
}
+/* Set the cached copy of the last ptid/waitstatus. */
+
+static void
+set_last_target_status (ptid_t ptid, struct target_waitstatus status)
+{
+ target_last_wait_ptid = ptid;
+ target_last_waitstatus = status;
+}
+
/* 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
struct regcache *regcache;
struct gdbarch *gdbarch;
struct address_space *aspace;
- CORE_ADDR breakpoint_pc;
+ CORE_ADDR breakpoint_pc, decr_pc;
/* If we've hit a breakpoint, we'll normally be stopped with SIGTRAP. If
we aren't, just return.
we have nothing to do. */
regcache = get_thread_regcache (ecs->ptid);
gdbarch = get_regcache_arch (regcache);
- if (gdbarch_decr_pc_after_break (gdbarch) == 0)
+
+ decr_pc = target_decr_pc_after_break (gdbarch);
+ if (decr_pc == 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);
+ breakpoint_pc = regcache_read_pc (regcache) - decr_pc;
/* Check whether there actually is a software breakpoint inserted at
that location.
{
struct cleanup *old_cleanups = make_cleanup (null_cleanup, NULL);
- if (RECORD_IS_USED)
+ if (record_full_is_used ())
record_full_gdb_operation_disable_set ();
/* When using hardware single-step, a SIGTRAP is reported for both
if (catch_syscall_enabled () > 0
&& catching_syscall_number (syscall_number) > 0)
{
- enum bpstat_signal_value sval;
-
if (debug_infrun)
fprintf_unfiltered (gdb_stdlog, "infrun: syscall number = '%d'\n",
syscall_number);
= bpstat_stop_status (get_regcache_aspace (regcache),
stop_pc, ecs->ptid, &ecs->ws);
- sval = bpstat_explains_signal (ecs->event_thread->control.stop_bpstat,
- GDB_SIGNAL_TRAP);
- ecs->random_signal = sval == BPSTAT_SIGNAL_NO;
-
- if (!ecs->random_signal)
+ if (bpstat_causes_stop (ecs->event_thread->control.stop_bpstat))
{
/* 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
ecs->stop_func_start
+= gdbarch_deprecated_function_start_offset (gdbarch);
+ if (gdbarch_skip_entrypoint_p (gdbarch))
+ ecs->stop_func_start = gdbarch_skip_entrypoint (gdbarch,
+ ecs->stop_func_start);
+
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. */
+
+/* Return the STOP_SOON field of the inferior pointed at by PTID. */
+
+static enum stop_kind
+get_inferior_stop_soon (ptid_t ptid)
+{
+ struct inferior *inf = find_inferior_pid (ptid_get_pid (ptid));
+
+ gdb_assert (inf != NULL);
+ return inf->control.stop_soon;
+}
+
+/* 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.
+
+ The alternatives are:
+
+ 1) stop_stepping and return; to really stop and return to the
+ debugger.
+
+ 2) keep_going and return; to wait for the next event (set
+ ecs->event_thread->stepping_over_breakpoint to 1 to single step
+ once). */
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)
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;
+ set_last_target_status (ecs->ptid, ecs->ws);
/* Always clear state belonging to the previous time we stopped. */
stop_stack_dummy = STOP_NONE;
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");
fprintf_unfiltered (gdb_stdlog,
"infrun: infwait_step_watch_state\n");
- stepped_after_stopped_by_watchpoint = 1;
+ ecs->stepped_after_stopped_by_watchpoint = 1;
break;
case infwait_nonstep_watch_state:
/* 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;
+ ecs->stepped_after_stopped_by_watchpoint = 1;
break;
default:
case TARGET_WAITKIND_LOADED:
if (debug_infrun)
fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_LOADED\n");
+ if (!ptid_equal (ecs->ptid, inferior_ptid))
+ context_switch (ecs->ptid);
/* 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. */
+
+ stop_soon = get_inferior_stop_soon (ecs->ptid);
if (stop_soon == NO_STOP_QUIETLY)
{
struct regcache *regcache;
- enum bpstat_signal_value sval;
- if (!ptid_equal (ecs->ptid, inferior_ptid))
- context_switch (ecs->ptid);
regcache = get_thread_regcache (ecs->ptid);
handle_solib_event ();
= bpstat_stop_status (get_regcache_aspace (regcache),
stop_pc, ecs->ptid, &ecs->ws);
- sval
- = bpstat_explains_signal (ecs->event_thread->control.stop_bpstat,
- GDB_SIGNAL_TRAP);
- ecs->random_signal = sval == BPSTAT_SIGNAL_NO;
-
- if (!ecs->random_signal)
+ if (bpstat_causes_stop (ecs->event_thread->control.stop_bpstat))
{
/* A catchpoint triggered. */
- ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_TRAP;
- goto process_event_stop_test;
+ process_event_stop_test (ecs);
+ return;
}
/* If requested, stop when the dynamic linker notifies
/* 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. */
+ we're running the program normally, also resume. */
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
return;
}
- break;
+ /* But stop if we're attaching or setting up a remote
+ connection. */
+ if (stop_soon == STOP_QUIETLY_NO_SIGSTOP
+ || stop_soon == STOP_QUIETLY_REMOTE)
+ {
+ if (debug_infrun)
+ fprintf_unfiltered (gdb_stdlog, "infrun: quietly stopped\n");
+ stop_stepping (ecs);
+ return;
+ }
+
+ internal_error (__FILE__, __LINE__,
+ _("unhandled stop_soon: %d"), (int) stop_soon);
case TARGET_WAITKIND_SPURIOUS:
if (debug_infrun)
handle_vfork_child_exec_or_exit (0);
target_terminal_ours (); /* Must do this before mourn anyway. */
+ /* Clearing any previous state of convenience variables. */
+ clear_exit_convenience_vars ();
+
if (ecs->ws.kind == TARGET_WAITKIND_EXITED)
{
/* Record the exit code in the convenience variable $_exitcode, so
print_exited_reason (ecs->ws.value.integer);
}
else
- print_signal_exited_reason (ecs->ws.value.sig);
+ {
+ struct regcache *regcache = get_thread_regcache (ecs->ptid);
+ struct gdbarch *gdbarch = get_regcache_arch (regcache);
+
+ if (gdbarch_gdb_signal_to_target_p (gdbarch))
+ {
+ /* Set the value of the internal variable $_exitsignal,
+ which holds the signal uncaught by the inferior. */
+ set_internalvar_integer (lookup_internalvar ("_exitsignal"),
+ gdbarch_gdb_signal_to_target (gdbarch,
+ ecs->ws.value.sig));
+ }
+ else
+ {
+ /* We don't have access to the target's method used for
+ converting between signal numbers (GDB's internal
+ representation <-> target's representation).
+ Therefore, we cannot do a good job at displaying this
+ information to the user. It's better to just warn
+ her about it (if infrun debugging is enabled), and
+ give up. */
+ if (debug_infrun)
+ fprintf_filtered (gdb_stdlog, _("\
+Cannot fill $_exitsignal with the correct signal number.\n"));
+ }
+
+ print_signal_exited_reason (ecs->ws.value.sig);
+ }
gdb_flush (gdb_stdout);
target_mourn_inferior ();
= 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)
+ /* If no catchpoint triggered for this, then keep going. 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. */
+ if (!bpstat_causes_stop (ecs->event_thread->control.stop_bpstat))
{
ptid_t parent;
ptid_t child;
stop_stepping (ecs);
return;
}
- ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_TRAP;
- goto process_event_stop_test;
+ process_event_stop_test (ecs);
+ return;
case TARGET_WAITKIND_VFORK_DONE:
/* Done with the shared memory region. Re-insert breakpoints in
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,
- GDB_SIGNAL_TRAP)
- == BPSTAT_SIGNAL_NO);
/* Note that this may be referenced from inside
bpstat_stop_status above, through inferior_has_execd. */
ecs->ws.value.execd_pathname = NULL;
/* If no catchpoint triggered for this, then keep going. */
- if (ecs->random_signal)
+ if (!bpstat_causes_stop (ecs->event_thread->control.stop_bpstat))
{
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;
+ process_event_stop_test (ecs);
+ return;
/* Be careful not to try to gather much state about a thread
that's in a syscall. It's frequently a losing proposition. */
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;
+ if (handle_syscall_event (ecs) == 0)
+ process_event_stop_test (ecs);
+ return;
/* Before examining the threads further, step this thread to
get it entirely out of the syscall. (We get notice of the
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;
+ if (handle_syscall_event (ecs) == 0)
+ process_event_stop_test (ecs);
+ return;
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;
+ handle_signal_stop (ecs);
+ return;
case TARGET_WAITKIND_NO_HISTORY:
if (debug_infrun)
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);
+/* Come here when the program has stopped with a 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). */
+static void
+handle_signal_stop (struct execution_control_state *ecs)
+{
+ struct frame_info *frame;
+ struct gdbarch *gdbarch;
+ int stopped_by_watchpoint;
+ enum stop_kind stop_soon;
+ int random_signal;
- if (ecs->event_thread->stop_requested
- && ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP)
- ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
- }
+ gdb_assert (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));
do_cleanups (old_chain);
}
- if (stepping_past_singlestep_breakpoint)
+ /* This is originated from start_remote(), start_inferior() and
+ shared libraries hook functions. */
+ stop_soon = get_inferior_stop_soon (ecs->ptid);
+ if (stop_soon == STOP_QUIETLY || stop_soon == STOP_QUIETLY_REMOTE)
{
- 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 (saved_singlestep_ptid));
-
- resume (1, GDB_SIGNAL_0);
- prepare_to_wait (ecs);
- return;
- }
+ if (!ptid_equal (ecs->ptid, inferior_ptid))
+ context_switch (ecs->ptid);
+ if (debug_infrun)
+ fprintf_unfiltered (gdb_stdlog, "infrun: quietly stopped\n");
+ stop_print_frame = 1;
+ stop_stepping (ecs);
+ return;
}
- if (!ptid_equal (deferred_step_ptid, null_ptid))
+ if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
+ && stop_after_trap)
{
- /* 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;
- }
+ if (!ptid_equal (ecs->ptid, inferior_ptid))
+ context_switch (ecs->ptid);
+ if (debug_infrun)
+ fprintf_unfiltered (gdb_stdlog, "infrun: stopped\n");
+ stop_print_frame = 0;
+ stop_stepping (ecs);
+ return;
+ }
- 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;
- }
+ /* 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.
- /* 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. */
+ 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.
- if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP)
+ 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))
{
- 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;
- }
+ stop_print_frame = 1;
+ stop_stepping (ecs);
+ ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
+ return;
}
- else
- ecs->random_signal = 1;
/* See if something interesting happened to the non-current thread. If
so, then switch to that thread. */
frame = get_current_frame ();
gdbarch = get_frame_arch (frame);
+ /* Pull the single step breakpoints out of the target. */
if (singlestep_breakpoints_inserted_p)
{
- /* Pull the single step breakpoints out of the target. */
+ /* However, before doing so, if this single-step breakpoint was
+ actually for another thread, set this thread up for moving
+ past it. */
+ if (!ptid_equal (ecs->ptid, singlestep_ptid)
+ && ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP)
+ {
+ struct regcache *regcache;
+ struct address_space *aspace;
+ CORE_ADDR pc;
+
+ regcache = get_thread_regcache (ecs->ptid);
+ aspace = get_regcache_aspace (regcache);
+ pc = regcache_read_pc (regcache);
+ if (single_step_breakpoint_inserted_here_p (aspace, pc))
+ {
+ if (debug_infrun)
+ {
+ fprintf_unfiltered (gdb_stdlog,
+ "infrun: [%s] hit step over single-step"
+ " breakpoint of [%s]\n",
+ target_pid_to_str (ecs->ptid),
+ target_pid_to_str (singlestep_ptid));
+ }
+ ecs->hit_singlestep_breakpoint = 1;
+ }
+ }
+
remove_single_step_breakpoints ();
singlestep_breakpoints_inserted_p = 0;
}
- if (stepped_after_stopped_by_watchpoint)
+ if (ecs->stepped_after_stopped_by_watchpoint)
stopped_by_watchpoint = 0;
else
stopped_by_watchpoint = watchpoints_triggered (&ecs->ws);
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
}
}
- /* 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_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
if (debug_infrun
&& ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
- && (bpstat_explains_signal (ecs->event_thread->control.stop_bpstat,
+ && !bpstat_explains_signal (ecs->event_thread->control.stop_bpstat,
GDB_SIGNAL_TRAP)
- == BPSTAT_SIGNAL_NO)
&& 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
+ /* NOTE: cagney/2003-03-29: These 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:
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,
- GDB_SIGNAL_TRAP)
- != BPSTAT_SIGNAL_NO)
- || 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
- {
- enum bpstat_signal_value sval;
-
- sval = bpstat_explains_signal (ecs->event_thread->control.stop_bpstat,
- ecs->event_thread->suspend.stop_signal);
- ecs->random_signal = (sval == BPSTAT_SIGNAL_NO);
+ /* See if the breakpoints module can explain the signal. */
+ random_signal
+ = !bpstat_explains_signal (ecs->event_thread->control.stop_bpstat,
+ ecs->event_thread->suspend.stop_signal);
- if (sval == BPSTAT_SIGNAL_HIDE)
- ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_TRAP;
- }
+ /* If not, perhaps stepping/nexting can. */
+ if (random_signal)
+ random_signal = !(ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
+ && currently_stepping (ecs->event_thread));
-process_event_stop_test:
+ /* Perhaps the thread hit a single-step breakpoint of _another_
+ thread. Single-step breakpoints are transparent to the
+ breakpoints module. */
+ if (random_signal)
+ random_signal = !ecs->hit_singlestep_breakpoint;
- /* 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);
+ /* No? Perhaps we got a moribund watchpoint. */
+ if (random_signal)
+ random_signal = !stopped_by_watchpoint;
/* For the program's own signals, act according to
the signal handling tables. */
- if (ecs->random_signal)
+ if (random_signal)
{
/* Signal not for debugging purposes. */
int printed = 0;
struct inferior *inf = find_inferior_pid (ptid_get_pid (ecs->ptid));
+ enum gdb_signal stop_signal = ecs->event_thread->suspend.stop_signal;
if (debug_infrun)
- fprintf_unfiltered (gdb_stdlog, "infrun: random signal %d\n",
- ecs->event_thread->suspend.stop_signal);
+ fprintf_unfiltered (gdb_stdlog, "infrun: random signal (%s)\n",
+ gdb_signal_to_symbol_string (stop_signal));
stopped_by_random_signal = 1;
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);
+
+ /* If we were nexting/stepping some other thread, switch to
+ it, so that we don't continue it, losing control. */
+ if (!switch_back_to_stepped_thread (ecs))
+ keep_going (ecs);
return;
}
(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)
+ if (!switch_back_to_stepped_thread (ecs))
{
- 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;
- }
+ "infrun: random signal, keep going\n");
- /* Insert a breakpoint at resume address. */
- insert_longjmp_resume_breakpoint (gdbarch, jmp_buf_pc);
- }
- else
- check_exception_resume (ecs, frame);
keep_going (ecs);
- return;
+ }
+ return;
+ }
- case BPSTAT_WHAT_CLEAR_LONGJMP_RESUME:
- {
- struct frame_info *init_frame;
+ process_event_stop_test (ecs);
+}
- /* There are several cases to consider.
+/* Come here when we've got some debug event / signal we can explain
+ (IOW, not a random signal), and test whether it should cause a
+ stop, or whether we should resume the inferior (transparently).
+ E.g., could be a breakpoint whose condition evaluates false; we
+ could be still stepping within the line; etc. */
- 1. The initiating frame no longer exists. In this case
- we must stop, because the exception or longjmp has gone
- too far.
+static void
+process_event_stop_test (struct execution_control_state *ecs)
+{
+ struct symtab_and_line stop_pc_sal;
+ struct frame_info *frame;
+ struct gdbarch *gdbarch;
+ CORE_ADDR jmp_buf_pc;
+ struct bpstat_what what;
- 2. The initiating frame exists, and is the same as the
- current frame. We stop, because the exception or
- longjmp has been caught.
+ /* Handle cases caused by hitting a breakpoint. */
- 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.
+ frame = get_current_frame ();
+ gdbarch = get_frame_arch (frame);
- 4. longjmp breakpoint has been placed just to protect
- against stale dummy frames and user is not interested
- in stopping around longjmps. */
+ what = bpstat_what (ecs->event_thread->control.stop_bpstat);
- if (debug_infrun)
- fprintf_unfiltered (gdb_stdlog,
- "infrun: BPSTAT_WHAT_CLEAR_LONGJMP_RESUME\n");
+ if (what.call_dummy)
+ {
+ stop_stack_dummy = what.call_dummy;
+ }
- gdb_assert (ecs->event_thread->control.exception_resume_breakpoint
- != NULL);
- delete_exception_resume_breakpoint (ecs->event_thread);
+ /* 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);
- if (what.is_longjmp)
- {
- check_longjmp_breakpoint_for_call_dummy (ecs->event_thread->num);
+ 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 (!frame_id_p (ecs->event_thread->initiating_frame))
- {
- /* Case 4. */
- keep_going (ecs);
- return;
- }
- }
+ if (debug_infrun)
+ fprintf_unfiltered (gdb_stdlog,
+ "infrun: BPSTAT_WHAT_SET_LONGJMP_RESUME\n");
- init_frame = frame_find_by_id (ecs->event_thread->initiating_frame);
+ ecs->event_thread->stepping_over_breakpoint = 1;
- 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;
- }
- }
+ 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;
+ }
- /* For Cases 1 and 2, remove the step-resume breakpoint,
- if it exists. */
- delete_step_resume_breakpoint (ecs->event_thread);
+ /* Insert a breakpoint at resume address. */
+ insert_longjmp_resume_breakpoint (gdbarch, jmp_buf_pc);
+ }
+ else
+ check_exception_resume (ecs, frame);
+ keep_going (ecs);
+ return;
- ecs->event_thread->control.stop_step = 1;
- print_end_stepping_range_reason ();
- stop_stepping (ecs);
- }
- return;
+ case BPSTAT_WHAT_CLEAR_LONGJMP_RESUME:
+ {
+ struct frame_info *init_frame;
- 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;
+ /* There are several cases to consider.
- case BPSTAT_WHAT_STEP_RESUME:
- if (debug_infrun)
- fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_STEP_RESUME\n");
+ 1. The initiating frame no longer exists. In this case we
+ must stop, because the exception or longjmp has gone too
+ far.
- 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;
+ 2. The initiating frame exists, and is the same as the
+ current frame. We stop, because the exception or longjmp
+ has been caught.
- case BPSTAT_WHAT_STOP_NOISY:
- if (debug_infrun)
- fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_STOP_NOISY\n");
- stop_print_frame = 1;
+ 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.
- /* We are about to nuke the step_resume_breakpointt via the
- cleanup chain, so no need to worry about it here. */
+ 4. longjmp breakpoint has been placed just to protect
+ against stale dummy frames and user is not interested in
+ stopping around longjmps. */
- stop_stepping (ecs);
- return;
+ if (debug_infrun)
+ fprintf_unfiltered (gdb_stdlog,
+ "infrun: BPSTAT_WHAT_CLEAR_LONGJMP_RESUME\n");
- case BPSTAT_WHAT_STOP_SILENT:
- if (debug_infrun)
- fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_STOP_SILENT\n");
- stop_print_frame = 0;
+ gdb_assert (ecs->event_thread->control.exception_resume_breakpoint
+ != NULL);
+ delete_exception_resume_breakpoint (ecs->event_thread);
- /* We are about to nuke the step_resume_breakpoin via the
- cleanup chain, so no need to worry about it here. */
+ if (what.is_longjmp)
+ {
+ check_longjmp_breakpoint_for_call_dummy (ecs->event_thread->num);
- stop_stepping (ecs);
- return;
+ if (!frame_id_p (ecs->event_thread->initiating_frame))
+ {
+ /* Case 4. */
+ keep_going (ecs);
+ return;
+ }
+ }
- case BPSTAT_WHAT_HP_STEP_RESUME:
- if (debug_infrun)
- fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_HP_STEP_RESUME\n");
+ init_frame = frame_find_by_id (ecs->event_thread->initiating_frame);
- 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;
+ 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;
+ }
+ }
- case BPSTAT_WHAT_KEEP_CHECKING:
- break;
- }
- }
+ /* For Cases 1 and 2, remove the step-resume breakpoint, if it
+ exists. */
+ delete_step_resume_breakpoint (ecs->event_thread);
- /* 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. */
+ ecs->event_thread->control.stop_step = 1;
+ print_end_stepping_range_reason ();
+ stop_stepping (ecs);
+ }
+ return;
- /* 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;
+ 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;
- 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;
- }
+ case BPSTAT_WHAT_STEP_RESUME:
+ if (debug_infrun)
+ fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_STEP_RESUME\n");
- /* 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.
+ 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;
- We can find a stepping dead thread in the thread list in
- two cases:
+ case BPSTAT_WHAT_STOP_NOISY:
+ if (debug_infrun)
+ fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_STOP_NOISY\n");
+ stop_print_frame = 1;
- - 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.
+ /* Assume the thread stopped for a breapoint. We'll still check
+ whether a/the breakpoint is there when the thread is next
+ resumed. */
+ ecs->event_thread->stepping_over_breakpoint = 1;
- - 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");
+ stop_stepping (ecs);
+ return;
- delete_thread (tp->ptid);
- keep_going (ecs);
- return;
- }
+ case BPSTAT_WHAT_STOP_SILENT:
+ if (debug_infrun)
+ fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_STOP_SILENT\n");
+ stop_print_frame = 0;
- /* 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;
+ /* Assume the thread stopped for a breapoint. We'll still check
+ whether a/the breakpoint is there when the thread is next
+ resumed. */
+ ecs->event_thread->stepping_over_breakpoint = 1;
+ stop_stepping (ecs);
+ return;
- if (debug_infrun)
- fprintf_unfiltered (gdb_stdlog,
- "infrun: switching back to stepped thread\n");
+ case BPSTAT_WHAT_HP_STEP_RESUME:
+ if (debug_infrun)
+ fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_HP_STEP_RESUME\n");
- ecs->event_thread = tp;
- ecs->ptid = tp->ptid;
- context_switch (ecs->ptid);
+ 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 (switch_back_to_stepped_thread (ecs))
+ return;
+
if (ecs->event_thread->control.step_resume_breakpoint)
{
if (debug_infrun)
or stepped back out of a signal handler to the first instruction
of the function. Just keep going, which will single-step back
to the caller. */
- if (ecs->stop_func_start != stop_pc)
+ if (ecs->stop_func_start != stop_pc && ecs->stop_func_start != 0)
{
struct symtab_and_line sr_sal;
keep_going (ecs);
}
+/* In all-stop mode, if we're currently stepping but have stopped in
+ some other thread, we may need to switch back to the stepped
+ thread. Returns true we set the inferior running, false if we left
+ it stopped (and the event needs further processing). */
+
+static int
+switch_back_to_stepped_thread (struct execution_control_state *ecs)
+{
+ if (!non_stop)
+ {
+ struct thread_info *tp;
+ struct thread_info *stepping_thread;
+
+ /* If any thread is blocked on some internal breakpoint, and we
+ simply need to step over that breakpoint to get it going
+ again, do that first. */
+
+ /* However, if we see an event for the stepping thread, then we
+ know all other threads have been moved past their breakpoints
+ already. Let the caller check whether the step is finished,
+ etc., before deciding to move it past a breakpoint. */
+ if (ecs->event_thread->control.step_range_end != 0)
+ return 0;
+
+ /* Check if the current thread is blocked on an incomplete
+ step-over, interrupted by a random signal. */
+ if (ecs->event_thread->control.trap_expected
+ && ecs->event_thread->suspend.stop_signal != GDB_SIGNAL_TRAP)
+ {
+ if (debug_infrun)
+ {
+ fprintf_unfiltered (gdb_stdlog,
+ "infrun: need to finish step-over of [%s]\n",
+ target_pid_to_str (ecs->event_thread->ptid));
+ }
+ keep_going (ecs);
+ return 1;
+ }
+
+ /* Check if the current thread is blocked by a single-step
+ breakpoint of another thread. */
+ if (ecs->hit_singlestep_breakpoint)
+ {
+ if (debug_infrun)
+ {
+ fprintf_unfiltered (gdb_stdlog,
+ "infrun: need to step [%s] over single-step "
+ "breakpoint\n",
+ target_pid_to_str (ecs->ptid));
+ }
+ keep_going (ecs);
+ return 1;
+ }
+
+ stepping_thread
+ = iterate_over_threads (currently_stepping_or_nexting_callback,
+ ecs->event_thread);
+
+ /* Check if any other thread except the stepping thread that
+ needs to start a step-over. Do that before actually
+ proceeding with step/next/etc. */
+ tp = find_thread_needs_step_over (stepping_thread != NULL,
+ stepping_thread);
+ if (tp != NULL)
+ {
+ if (debug_infrun)
+ {
+ fprintf_unfiltered (gdb_stdlog,
+ "infrun: need to step-over [%s]\n",
+ target_pid_to_str (tp->ptid));
+ }
+
+ gdb_assert (!tp->control.trap_expected);
+ gdb_assert (tp->control.step_range_end == 0);
+
+ /* We no longer expect a trap in the current thread. Clear
+ the trap_expected flag before switching. This is what
+ keep_going would do as well, if we called it. */
+ ecs->event_thread->control.trap_expected = 0;
+
+ ecs->ptid = tp->ptid;
+ ecs->event_thread = tp;
+ switch_to_thread (ecs->ptid);
+ keep_going (ecs);
+ return 1;
+ }
+
+ tp = stepping_thread;
+ if (tp != NULL)
+ {
+ struct frame_info *frame;
+ struct gdbarch *gdbarch;
+
+ /* 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 1;
+ }
+
+ /* 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);
+
+ stop_pc = regcache_read_pc (get_thread_regcache (ecs->ptid));
+ frame = get_current_frame ();
+ gdbarch = get_frame_arch (frame);
+
+ /* If the PC of the thread we were trying to single-step has
+ changed, then that thread has trapped or been signaled,
+ but the event has not been reported to GDB yet. Re-poll
+ the target looking for this particular thread's event
+ (i.e. temporarily enable schedlock) by:
+
+ - setting a break at the current PC
+ - resuming that particular thread, only (by setting
+ trap expected)
+
+ This prevents us continuously moving the single-step
+ breakpoint forward, one instruction at a time,
+ overstepping. */
+
+ if (gdbarch_software_single_step_p (gdbarch)
+ && stop_pc != tp->prev_pc)
+ {
+ if (debug_infrun)
+ fprintf_unfiltered (gdb_stdlog,
+ "infrun: expected thread advanced also\n");
+
+ insert_single_step_breakpoint (get_frame_arch (frame),
+ get_frame_address_space (frame),
+ stop_pc);
+ singlestep_breakpoints_inserted_p = 1;
+ ecs->event_thread->control.trap_expected = 1;
+ singlestep_ptid = inferior_ptid;
+ singlestep_pc = stop_pc;
+
+ resume (0, GDB_SIGNAL_0);
+ prepare_to_wait (ecs);
+ }
+ else
+ {
+ if (debug_infrun)
+ fprintf_unfiltered (gdb_stdlog,
+ "infrun: expected thread still "
+ "hasn't advanced\n");
+ keep_going (ecs);
+ }
+
+ return 1;
+ }
+ }
+ return 0;
+}
+
/* Is thread TP in the middle of single-stepping? */
static int
static void
insert_exception_resume_from_probe (struct thread_info *tp,
- const struct probe *probe,
+ const struct bound_probe *probe,
struct frame_info *frame)
{
struct value *arg_value;
struct frame_info *frame)
{
volatile struct gdb_exception e;
- const struct probe *probe;
+ struct bound_probe probe;
struct symbol *func;
/* First see if this exception unwinding breakpoint was set via a
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));
- if (probe)
+ if (probe.probe)
{
- insert_exception_resume_from_probe (ecs->event_thread, probe, frame);
+ insert_exception_resume_from_probe (ecs->event_thread, &probe, frame);
return;
}
if (debug_infrun)
fprintf_unfiltered (gdb_stdlog, "infrun: stop_stepping\n");
+ clear_step_over_info ();
+
/* 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). */
+/* Called when we should continue running the inferior, because the
+ current event doesn't cause a user visible stop. This does the
+ resuming part; waiting for the next event is done elsewhere. */
static void
keep_going (struct execution_control_state *ecs)
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. */
-
+ /* We haven't yet gotten our trap, and either: intercepted a
+ non-signal event (e.g., a fork); or took a signal which we
+ are supposed to pass through to the inferior. Simply
+ continue. */
discard_cleanups (old_cleanups);
resume (currently_stepping (ecs->event_thread),
ecs->event_thread->suspend.stop_signal);
}
else
{
+ volatile struct gdb_exception e;
+ struct regcache *regcache = get_current_regcache ();
+
/* 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.
+ anyway (if we got a signal, the user asked it be passed to
+ the child)
+ -- or --
+ We got our expected trap, but decided we should resume from
+ it.
- We're going to run this baby now!
+ 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 ();
+ /* If we need to step over a breakpoint, and we're not using
+ displaced stepping to do so, insert all breakpoints
+ (watchpoints, etc.) but the one we're stepping over, step one
+ instruction, and then re-insert the breakpoint when that step
+ is finished. */
+ if ((ecs->hit_singlestep_breakpoint
+ || thread_still_needs_step_over (ecs->event_thread))
+ && !use_displaced_stepping (get_regcache_arch (regcache)))
+ {
+ set_step_over_info (get_regcache_aspace (regcache),
+ regcache_read_pc (regcache));
}
else
- {
- volatile struct gdb_exception e;
+ clear_step_over_info ();
- /* 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;
- }
+ /* Stop stepping if inserting breakpoints fails. */
+ 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. */
-
+ = (ecs->event_thread->stepping_over_breakpoint
+ || ecs->hit_singlestep_breakpoint);
+
+ /* Do not deliver GDB_SIGNAL_TRAP (except when the user
+ explicitly specifies that such a signal should be delivered
+ to the target program). Typically, that would occur when a
+ user is debugging a target monitor on a simulator: the target
+ monitor sets a breakpoint; the simulator encounters this
+ breakpoint and halts the simulation handing control to GDB;
+ GDB, noting that the stop address doesn't map to any known
+ breakpoint, returns control back to the simulator; the
+ simulator then delivers the hardware equivalent of a
+ GDB_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;
ui_out_text (current_uiout, "\nNo more reverse-execution history.\n");
}
+/* 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. */
+
+void
+print_stop_event (struct target_waitstatus *ws)
+{
+ 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, ws->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))
+ {
+ /* Finished step, just print source line. */
+ source_flag = SRC_LINE;
+ }
+ else
+ {
+ /* Print location and source line. */
+ source_flag = SRC_AND_LOC;
+ }
+ break;
+ case PRINT_SRC_AND_LOC:
+ /* Print location and source line. */
+ source_flag = SRC_AND_LOC;
+ break;
+ case PRINT_SRC_ONLY:
+ source_flag = SRC_LINE;
+ break;
+ case PRINT_NOTHING:
+ /* Something bogus. */
+ source_flag = SRC_LINE;
+ 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, 1);
+
+ /* Display the auto-display expressions. */
+ do_displays ();
+}
+
/* Here to return control to GDB when the inferior stops for real.
Print appropriate messages, remove breakpoints, give terminal our modes.
&& 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". */
+ "received a signal".
+
+ Also skip saying anything in non-stop mode. In that mode, as 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, fetch_inferior_event installs a cleanup to restore
+ the current thread back to the thread the user had selected right
+ after this event is handled, so we're not really switching, only
+ informing of a stop. */
if (!non_stop
&& !ptid_equal (previous_inferior_ptid, inferior_ptid)
&& target_has_execution
{
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 ();
- }
+ print_stop_event (&last);
}
/* Save the function value return registers, if we care.
}
}
- inf_state = XZALLOC (struct infcall_suspend_state);
+ inf_state = XCNEW (struct infcall_suspend_state);
if (siginfo_data)
{
xfree (inf_status);
}
\f
-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(). */
*saved_ptid_ptr = inferior_ptid;
return make_cleanup (restore_inferior_ptid, saved_ptid_ptr);
}
+
+/* See inferior.h. */
+
+void
+clear_exit_convenience_vars (void)
+{
+ clear_internalvar (lookup_internalvar ("_exitsignal"));
+ clear_internalvar (lookup_internalvar ("_exitcode"));
+}
\f
/* User interface for reverse debugging:
}
}
-/* 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)
projects / deliverable / binutils-gdb.git / blobdiff