process.
Copyright (C) 1986, 1987, 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995,
- 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007
- Free Software Foundation, Inc.
+ 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007,
+ 2008 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 2 of the License, or
+ 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,
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, write to the Free Software
- Foundation, Inc., 51 Franklin Street, Fifth Floor,
- Boston, MA 02110-1301, USA. */
+ along with this program. If not, see <http://www.gnu.org/licenses/>. */
#include "defs.h"
#include "gdb_string.h"
static void xdb_handle_command (char *args, int from_tty);
-static int prepare_to_proceed (void);
+static int prepare_to_proceed (int);
void _initialize_infrun (void);
-int inferior_ignoring_startup_exec_events = 0;
-int inferior_ignoring_leading_exec_events = 0;
-
/* 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. */
static ptid_t previous_inferior_ptid;
-/* This is true for configurations that may follow through execl() and
- similar functions. At present this is only true for HP-UX native. */
-
-#ifndef MAY_FOLLOW_EXEC
-#define MAY_FOLLOW_EXEC (0)
-#endif
-
-static int may_follow_exec = MAY_FOLLOW_EXEC;
-
static int debug_infrun = 0;
static void
show_debug_infrun (struct ui_file *file, int from_tty,
static struct cmd_list_element *stop_command;
-/* Nonzero if breakpoints are now inserted in the inferior. */
-
-static int breakpoints_inserted;
-
/* Function inferior was in as of last step command. */
static struct symbol *step_start_function;
-/* Nonzero if we are expecting a trace trap and should proceed from it. */
+/* Nonzero if we are presently stepping over a breakpoint.
+
+ If we hit a breakpoint or watchpoint, and then continue,
+ we need to single step the current thread with breakpoints
+ disabled, to avoid hitting the same breakpoint or
+ watchpoint again. And we should step just a single
+ thread and keep other threads stopped, so that
+ other threads don't miss breakpoints while they are removed.
+
+ So, this variable simultaneously means that we need to single
+ step the current thread, keep other threads stopped, and that
+ breakpoints should be removed while we step.
-static int trap_expected;
+ This variable is set either:
+ - in proceed, when we resume inferior on user's explicit request
+ - in keep_going, if handle_inferior_event decides we need to
+ step over breakpoint.
+
+ The variable is cleared in clear_proceed_status, called every
+ time before we call proceed. The proceed calls wait_for_inferior,
+ which calls handle_inferior_event in a loop, and until
+ wait_for_inferior exits, this variable is changed only by keep_going. */
+
+static int stepping_over_breakpoint;
/* Nonzero if we want to give control to the user when we're notified
of shared library events by the dynamic linker. */
int saved_pid = pid;
struct target_ops *tgt;
- if (!may_follow_exec)
- return;
-
/* 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.
/* We've followed the inferior through an exec. Therefore, the
inferior has essentially been killed & reborn. */
- /* First collect the run target in effect. */
- tgt = find_run_target ();
- /* If we can't find one, things are in a very strange state... */
- if (tgt == NULL)
- error (_("Could find run target to save before following exec"));
-
gdb_flush (gdb_stdout);
- target_mourn_inferior ();
- inferior_ptid = pid_to_ptid (saved_pid);
+ generic_mourn_inferior ();
/* Because mourn_inferior resets inferior_ptid. */
- push_target (tgt);
+ inferior_ptid = pid_to_ptid (saved_pid);
+
+ 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;
+ }
/* That a.out is now the one to use. */
exec_file_attach (execd_pathname, 0);
/* 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. */
-#if defined(SOLIB_RESTART)
- SOLIB_RESTART ();
-#endif
+ no_shared_libraries (NULL, 0);
#ifdef SOLIB_CREATE_INFERIOR_HOOK
SOLIB_CREATE_INFERIOR_HOOK (PIDGET (inferior_ptid));
#else
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;
\f
/* Things to clean up if we QUIT out of resume (). */
Work around the problem by removing hardware watchpoints if a step is
requested, GDB will check for a hardware watchpoint trigger after the
step anyway. */
- if (CANNOT_STEP_HW_WATCHPOINTS && step && breakpoints_inserted)
+ if (CANNOT_STEP_HW_WATCHPOINTS && step)
remove_hw_watchpoints ();
a command like `return' or `jump' to continue execution."));
}
- if (SOFTWARE_SINGLE_STEP_P () && step)
+ if (step && gdbarch_software_single_step_p (current_gdbarch))
{
/* Do it the hard way, w/temp breakpoints */
- if (SOFTWARE_SINGLE_STEP (get_current_frame ()))
+ if (gdbarch_software_single_step (current_gdbarch, get_current_frame ()))
{
/* ...and don't ask hardware to do it. */
step = 0;
resume_ptid = RESUME_ALL; /* Default */
- if ((step || singlestep_breakpoints_inserted_p)
- && (stepping_past_singlestep_breakpoint
- || (!breakpoints_inserted && breakpoint_here_p (read_pc ()))))
+ /* 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));
+
+ if (singlestep_breakpoints_inserted_p
+ && stepping_past_singlestep_breakpoint)
{
- /* Stepping past a breakpoint without inserting breakpoints.
- Make sure only the current thread gets to step, so that
- other threads don't sneak past breakpoints while they are
- not inserted. */
+ /* 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;
+ }
+ if ((step || singlestep_breakpoints_inserted_p)
+ && stepping_over_breakpoint)
+ {
+ /* 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;
}
/* 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 && breakpoints_inserted && breakpoint_here_p (read_pc ()))
+ if (step && breakpoint_inserted_here_p (read_pc ()))
step = 0;
}
target_resume (resume_ptid, step, sig);
void
clear_proceed_status (void)
{
- trap_expected = 0;
+ stepping_over_breakpoint = 0;
step_range_start = 0;
step_range_end = 0;
step_frame_id = null_frame_id;
/* This should be suitable for any targets that support threads. */
static int
-prepare_to_proceed (void)
+prepare_to_proceed (int step)
{
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);
- /* Make sure we were stopped either at a breakpoint, or because
- of a Ctrl-C. */
+ /* Make sure we were stopped at a breakpoint. */
if (wait_status.kind != TARGET_WAITKIND_STOPPED
- || (wait_status.value.sig != TARGET_SIGNAL_TRAP
- && wait_status.value.sig != TARGET_SIGNAL_INT))
+ || wait_status.value.sig != TARGET_SIGNAL_TRAP)
{
return 0;
}
+ /* Switched over from WAIT_PID. */
if (!ptid_equal (wait_ptid, minus_one_ptid)
- && !ptid_equal (inferior_ptid, wait_ptid))
+ && !ptid_equal (inferior_ptid, wait_ptid)
+ && breakpoint_here_p (read_pc_pid (wait_ptid)))
{
- /* Switched over from WAIT_PID. */
- CORE_ADDR wait_pc = read_pc_pid (wait_ptid);
-
- if (wait_pc != read_pc ())
+ /* If stepping, remember current thread to switch back to. */
+ if (step)
{
- /* Switch back to WAIT_PID thread. */
- inferior_ptid = wait_ptid;
-
- /* FIXME: This stuff came from switch_to_thread() in
- thread.c (which should probably be a public function). */
- reinit_frame_cache ();
- registers_changed ();
- stop_pc = wait_pc;
+ deferred_step_ptid = inferior_ptid;
}
+ /* Switch back to WAIT_PID thread. */
+ switch_to_thread (wait_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. */
- if (breakpoint_here_p (wait_pc))
- return 1;
+ so we need to step over it before continuing to avoid
+ hitting it straight away. */
+ return 1;
}
return 0;
-
}
/* Record the pc of the program the last time it stopped. This is
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 () && breakpoint_here_p (read_pc ()))
+ if (prepare_to_proceed (step))
oneproc = 1;
if (oneproc)
- /* We will get a trace trap after one instruction.
- Continue it automatically and insert breakpoints then. */
- trap_expected = 1;
- else
{
- insert_breakpoints ();
- /* If we get here there was no call to error() in
- insert breakpoints -- so they were inserted. */
- breakpoints_inserted = 1;
+ /* We will get a trace trap after one instruction.
+ Continue it automatically and insert breakpoints then. */
+ stepping_over_breakpoint = 1;
+ /* FIXME: if breakpoints are always inserted, we'll trap
+ if trying to single-step over breakpoint. Disable
+ all breakpoints. In future, we'd need to invent some
+ smart way of stepping over breakpoint instruction without
+ hitting breakpoint. */
+ remove_breakpoints ();
}
+ else
+ insert_breakpoints ();
if (siggnal != TARGET_SIGNAL_DEFAULT)
stop_signal = siggnal;
does not support asynchronous execution. */
if (!target_can_async_p ())
{
- wait_for_inferior ();
+ wait_for_inferior (0);
normal_stop ();
}
}
{
init_thread_list ();
init_wait_for_inferior ();
- stop_soon = STOP_QUIETLY;
- trap_expected = 0;
+ stop_soon = STOP_QUIETLY_REMOTE;
+ stepping_over_breakpoint = 0;
/* Always go on waiting for the target, regardless of the mode. */
/* FIXME: cagney/1999-09-23: At present it isn't possible to
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 ();
+ wait_for_inferior (0);
/* Now that the inferior has stopped, do any bookkeeping like
loading shared libraries. We want to do this before normal_stop,
/* These are meaningless until the first time through wait_for_inferior. */
prev_pc = 0;
- breakpoints_inserted = 0;
breakpoint_init_inferior (inf_starting);
/* Don't confuse first call to proceed(). */
clear_proceed_status ();
stepping_past_singlestep_breakpoint = 0;
+ deferred_step_ptid = null_ptid;
+
+ target_last_wait_ptid = minus_one_ptid;
}
\f
/* This enum encodes possible reasons for doing a target_wait, so that
{
infwait_normal_state,
infwait_thread_hop_state,
+ infwait_step_watch_state,
infwait_nonstep_watch_state
};
{
struct target_waitstatus ws;
struct target_waitstatus *wp;
- int another_trap;
+ /* Should we step over breakpoint next time keep_going
+ is called? */
+ int stepping_over_breakpoint;
int random_signal;
CORE_ADDR stop_func_start;
CORE_ADDR stop_func_end;
int stop_info);
/* Wait for control to return from inferior to debugger.
+
+ If TREAT_EXEC_AS_SIGTRAP is non-zero, then handle EXEC signals
+ as if they were SIGTRAP signals. This can be useful during
+ the startup sequence on some targets such as HP/UX, where
+ we receive an EXEC event instead of the expected SIGTRAP.
+
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)
+wait_for_inferior (int treat_exec_as_sigtrap)
{
struct cleanup *old_cleanups;
struct execution_control_state ecss;
struct execution_control_state *ecs;
if (debug_infrun)
- fprintf_unfiltered (gdb_stdlog, "infrun: wait_for_inferior\n");
+ fprintf_unfiltered
+ (gdb_stdlog, "infrun: wait_for_inferior (treat_exec_as_sigtrap=%d)\n",
+ treat_exec_as_sigtrap);
old_cleanups = make_cleanup (delete_step_resume_breakpoint,
&step_resume_breakpoint);
else
ecs->ptid = target_wait (ecs->waiton_ptid, ecs->wp);
+ if (treat_exec_as_sigtrap && ecs->ws.kind == TARGET_WAITKIND_EXECD)
+ {
+ xfree (ecs->ws.value.execd_pathname);
+ ecs->ws.kind = TARGET_WAITKIND_STOPPED;
+ ecs->ws.value.sig = TARGET_SIGNAL_TRAP;
+ }
+
/* Now figure out what to do with the result of the result. */
handle_inferior_event (ecs);
if (!async_ecs->wait_some_more)
{
- old_cleanups = make_exec_cleanup (delete_step_resume_breakpoint,
- &step_resume_breakpoint);
-
/* Fill in with reasonable starting values. */
init_execution_control_state (async_ecs);
if (!async_ecs->wait_some_more)
{
- /* Do only the cleanups that have been added by this
- function. Let the continuations for the commands do the rest,
- if there are any. */
- do_exec_cleanups (old_cleanups);
+ delete_step_resume_breakpoint (&step_resume_breakpoint);
+
normal_stop ();
if (step_multi && stop_step)
inferior_event_handler (INF_EXEC_CONTINUE, NULL);
void
init_execution_control_state (struct execution_control_state *ecs)
{
- ecs->another_trap = 0;
+ ecs->stepping_over_breakpoint = 0;
ecs->random_signal = 0;
ecs->step_after_step_resume_breakpoint = 0;
ecs->handling_longjmp = 0; /* FIXME */
{ /* Perform infrun state context switch: */
/* Save infrun state for the old thread. */
save_infrun_state (inferior_ptid, prev_pc,
- trap_expected, step_resume_breakpoint,
+ stepping_over_breakpoint, step_resume_breakpoint,
step_range_start,
step_range_end, &step_frame_id,
- ecs->handling_longjmp, ecs->another_trap,
+ ecs->handling_longjmp, ecs->stepping_over_breakpoint,
ecs->stepping_through_solib_after_catch,
ecs->stepping_through_solib_catchpoints,
ecs->current_line, ecs->current_symtab);
/* Load infrun state for the new thread. */
load_infrun_state (ecs->ptid, &prev_pc,
- &trap_expected, &step_resume_breakpoint,
+ &stepping_over_breakpoint, &step_resume_breakpoint,
&step_range_start,
&step_range_end, &step_frame_id,
- &ecs->handling_longjmp, &ecs->another_trap,
+ &ecs->handling_longjmp, &ecs->stepping_over_breakpoint,
&ecs->stepping_through_solib_after_catch,
&ecs->stepping_through_solib_catchpoints,
&ecs->current_line, &ecs->current_symtab);
}
- inferior_ptid = ecs->ptid;
- reinit_frame_cache ();
+
+ switch_to_thread (ecs->ptid);
}
static void
breakpoint_pc = read_pc_pid (ecs->ptid) - gdbarch_decr_pc_after_break
(current_gdbarch);
- if (SOFTWARE_SINGLE_STEP_P ())
- {
- /* When using software single-step, a SIGTRAP can only indicate
- an inserted breakpoint. This actually makes things
- easier. */
- if (singlestep_breakpoints_inserted_p)
- /* When software single stepping, the instruction at [prev_pc]
- is never a breakpoint, but the instruction following
- [prev_pc] (in program execution order) always is. Assume
- that following instruction was reached and hence a software
- breakpoint was hit. */
- write_pc_pid (breakpoint_pc, ecs->ptid);
- else if (software_breakpoint_inserted_here_p (breakpoint_pc))
- /* The inferior was free running (i.e., no single-step
- breakpoints inserted) and it hit a software breakpoint. */
- write_pc_pid (breakpoint_pc, ecs->ptid);
- }
- else
+ /* Check whether there actually is a software breakpoint inserted
+ at that location. */
+ if (software_breakpoint_inserted_here_p (breakpoint_pc))
{
- /* 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.
-
- When the thread to be examined does not match the current thread
- context we can't use currently_stepping, so assume no
- single-stepping in this case. */
- if (ptid_equal (ecs->ptid, inferior_ptid) && currently_stepping (ecs))
- {
- if (prev_pc == breakpoint_pc
- && software_breakpoint_inserted_here_p (breakpoint_pc))
- /* Hardware single-stepped a software breakpoint (as
- occures when the inferior is resumed with PC pointing
- at not-yet-hit software breakpoint). Since the
- breakpoint really is executed, the inferior needs to be
- backed up to the breakpoint address. */
- write_pc_pid (breakpoint_pc, ecs->ptid);
- }
- else
- {
- if (software_breakpoint_inserted_here_p (breakpoint_pc))
- /* The inferior was free running (i.e., no hardware
- single-step and no possibility of a false SIGTRAP) and
- hit a software breakpoint. */
- write_pc_pid (breakpoint_pc, ecs->ptid);
- }
+ /* 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)
+ || prev_pc == breakpoint_pc)
+ write_pc_pid (breakpoint_pc, ecs->ptid);
}
}
by an event from the inferior, figure out what it means and take
appropriate action. */
-int stepped_after_stopped_by_watchpoint;
-
void
handle_inferior_event (struct execution_control_state *ecs)
{
- /* NOTE: bje/2005-05-02: If you're looking at this code and thinking
- that the variable stepped_after_stopped_by_watchpoint isn't used,
- then you're wrong! See remote.c:remote_stopped_data_address. */
-
int sw_single_step_trap_p = 0;
- int stopped_by_watchpoint = -1; /* Mark as unknown. */
+ int stopped_by_watchpoint;
+ int stepped_after_stopped_by_watchpoint = 0;
/* Cache the last pid/waitstatus. */
target_last_wait_ptid = ecs->ptid;
target_last_waitstatus = *ecs->wp;
+ /* Always clear state belonging to the previous time we stopped. */
+ stop_stack_dummy = 0;
+
adjust_pc_after_break (ecs);
switch (ecs->infwait_state)
case infwait_normal_state:
if (debug_infrun)
fprintf_unfiltered (gdb_stdlog, "infrun: infwait_normal_state\n");
- stepped_after_stopped_by_watchpoint = 0;
+ 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 (ecs->ws.kind != TARGET_WAITKIND_EXITED
&& ecs->ws.kind != TARGET_WAITKIND_SIGNALLED && ecs->new_thread_event)
- {
- add_thread (ecs->ptid);
-
- ui_out_text (uiout, "[New ");
- ui_out_text (uiout, target_pid_or_tid_to_str (ecs->ptid));
- ui_out_text (uiout, "]\n");
- }
+ add_thread (ecs->ptid);
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. */
-#ifdef SOLIB_ADD
+ /* 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)
{
- /* Remove breakpoints, SOLIB_ADD might adjust
- breakpoint addresses via breakpoint_re_set. */
- if (breakpoints_inserted)
- remove_breakpoints ();
-
/* Check for any newly added shared libraries if we're
supposed to be adding them automatically. Switch
terminal for any messages produced by
exec/process stratum, instead relying on the target stack
to propagate relevant changes (stop, section table
changed, ...) up to other layers. */
+#ifdef SOLIB_ADD
SOLIB_ADD (NULL, 0, ¤t_target, auto_solib_add);
+#else
+ solib_add (NULL, 0, ¤t_target, auto_solib_add);
+#endif
target_terminal_inferior ();
- /* Reinsert breakpoints and continue. */
- if (breakpoints_inserted)
+ /* 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). */
+ if (stop_on_solib_events)
+ {
+ stop_stepping (ecs);
+ return;
+ }
+
+ /* NOTE drow/2007-05-11: This might be a good place to check
+ for "catch load". */
+ }
+
+ /* 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)
+ {
+ /* Loading of shared libraries might have changed breakpoint
+ addresses. Make sure new breakpoints are inserted. */
+ if (!breakpoints_always_inserted_mode ())
insert_breakpoints ();
+ resume (0, TARGET_SIGNAL_0);
+ prepare_to_wait (ecs);
+ return;
}
-#endif
- resume (0, TARGET_SIGNAL_0);
- prepare_to_wait (ecs);
- return;
+
+ break;
case TARGET_WAITKIND_SPURIOUS:
if (debug_infrun)
(LONGEST) ecs->ws.value.integer));
gdb_flush (gdb_stdout);
target_mourn_inferior ();
- singlestep_breakpoints_inserted_p = 0; /* SOFTWARE_SINGLE_STEP_P() */
+ singlestep_breakpoints_inserted_p = 0;
stop_print_frame = 0;
stop_stepping (ecs);
return;
target_mourn_inferior ();
print_stop_reason (SIGNAL_EXITED, stop_signal);
- singlestep_breakpoints_inserted_p = 0; /* SOFTWARE_SINGLE_STEP_P() */
+ singlestep_breakpoints_inserted_p = 0;
stop_stepping (ecs);
return;
stop_pc = read_pc ();
- stop_bpstat = bpstat_stop_status (stop_pc, ecs->ptid, 0);
+ stop_bpstat = bpstat_stop_status (stop_pc, ecs->ptid);
ecs->random_signal = !bpstat_explains_signal (stop_bpstat);
fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_EXECD\n");
stop_signal = TARGET_SIGNAL_TRAP;
- /* NOTE drow/2002-12-05: This code should be pushed down into the
- target_wait function. Until then following vfork on HP/UX 10.20
- is probably broken by this. Of course, it's broken anyway. */
- /* Is this a target which reports multiple exec events per actual
- call to exec()? (HP-UX using ptrace does, for example.) If so,
- ignore all but the last one. Just resume the exec'r, and wait
- for the next exec event. */
- if (inferior_ignoring_leading_exec_events)
- {
- inferior_ignoring_leading_exec_events--;
- target_resume (ecs->ptid, 0, TARGET_SIGNAL_0);
- prepare_to_wait (ecs);
- return;
- }
- inferior_ignoring_leading_exec_events =
- target_reported_exec_events_per_exec_call () - 1;
-
pending_follow.execd_pathname =
savestring (ecs->ws.value.execd_pathname,
strlen (ecs->ws.value.execd_pathname));
ecs->saved_inferior_ptid = inferior_ptid;
inferior_ptid = ecs->ptid;
- stop_bpstat = bpstat_stop_status (stop_pc, ecs->ptid, 0);
+ stop_bpstat = bpstat_stop_status (stop_pc, ecs->ptid);
ecs->random_signal = !bpstat_explains_signal (stop_bpstat);
inferior_ptid = ecs->saved_inferior_ptid;
if (stepping_past_singlestep_breakpoint)
{
- gdb_assert (SOFTWARE_SINGLE_STEP_P ()
- && singlestep_breakpoints_inserted_p);
+ 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;
+ if (!ptid_equal (deferred_step_ptid, null_ptid))
+ {
+ /* If we stopped for some other reason than single-stepping, ignore
+ the fact that we were supposed to switch back. */
+ if (stop_signal == TARGET_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)
+ {
+ remove_single_step_breakpoints ();
+ singlestep_breakpoints_inserted_p = 0;
+ }
+
+ /* Note: We do not call context_switch at this point, as the
+ context is already set up for stepping the original thread. */
+ switch_to_thread (deferred_step_ptid);
+ deferred_step_ptid = null_ptid;
+ /* Suppress spurious "Switching to ..." message. */
+ previous_inferior_ptid = inferior_ptid;
+
+ resume (1, TARGET_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. */
/* 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 (breakpoints_inserted && breakpoint_here_p (stop_pc))
+ if (regular_breakpoint_inserted_here_p (stop_pc))
{
ecs->random_signal = 0;
if (!breakpoint_thread_match (stop_pc, ecs->ptid))
thread_hop_needed = 1;
}
- else if (SOFTWARE_SINGLE_STEP_P () && singlestep_breakpoints_inserted_p)
+ 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. */
/* Saw a breakpoint, but it was hit by the wrong thread.
Just continue. */
- if (SOFTWARE_SINGLE_STEP_P () && singlestep_breakpoints_inserted_p)
+ if (singlestep_breakpoints_inserted_p)
{
/* Pull the single step breakpoints out of the target. */
remove_single_step_breakpoints ();
process until the child exits (well, okay, not
then either :-) or execs. */
if (remove_status != 0)
- {
- /* FIXME! This is obviously non-portable! */
- write_pc_pid (stop_pc + 4, ecs->ptid);
- /* We need to restart all the threads now,
- * unles we're running in scheduler-locked mode.
- * Use currently_stepping to determine whether to
- * step or continue.
- */
- /* FIXME MVS: is there any reason not to call resume()? */
- if (scheduler_mode == schedlock_on)
- target_resume (ecs->ptid,
- currently_stepping (ecs), TARGET_SIGNAL_0);
- else
- target_resume (RESUME_ALL,
- currently_stepping (ecs), TARGET_SIGNAL_0);
- prepare_to_wait (ecs);
- return;
- }
+ error (_("Cannot step over breakpoint hit in wrong thread"));
else
{ /* Single step */
- breakpoints_inserted = 0;
if (!ptid_equal (inferior_ptid, ecs->ptid))
context_switch (ecs);
ecs->waiton_ptid = ecs->ptid;
ecs->wp = &(ecs->ws);
- ecs->another_trap = 1;
+ ecs->stepping_over_breakpoint = 1;
ecs->infwait_state = infwait_thread_hop_state;
keep_going (ecs);
return;
}
}
- else if (SOFTWARE_SINGLE_STEP_P () && singlestep_breakpoints_inserted_p)
+ else if (singlestep_breakpoints_inserted_p)
{
sw_single_step_trap_p = 1;
ecs->random_signal = 0;
deprecated_context_hook (pid_to_thread_id (ecs->ptid));
}
- if (SOFTWARE_SINGLE_STEP_P () && singlestep_breakpoints_inserted_p)
+ if (singlestep_breakpoints_inserted_p)
{
/* Pull the single step breakpoints out of the target. */
remove_single_step_breakpoints ();
singlestep_breakpoints_inserted_p = 0;
}
- /* 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. */
- if (HAVE_STEPPABLE_WATCHPOINT && STOPPED_BY_WATCHPOINT (ecs->ws))
+ 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
+ && (HAVE_STEPPABLE_WATCHPOINT
+ || gdbarch_have_nonsteppable_watchpoint (current_gdbarch)))
{
if (debug_infrun)
fprintf_unfiltered (gdb_stdlog, "infrun: STOPPED_BY_WATCHPOINT\n");
- resume (1, 0);
- prepare_to_wait (ecs);
- return;
- }
- /* It is far more common to need to disable a watchpoint to step
- the inferior over it. FIXME. What else might a debug
- register or page protection watchpoint scheme need here? */
- if (gdbarch_have_nonsteppable_watchpoint (current_gdbarch)
- && STOPPED_BY_WATCHPOINT (ecs->ws))
- {
/* 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
In order to make watchpoints work `right', we really need
to complete the memory write, and then evaluate the
- watchpoint expression. The following code does that by
- removing the watchpoint (actually, all watchpoints and
- breakpoints), single-stepping the target, re-inserting
- watchpoints, and then falling through to let normal
- single-step processing handle proceed. Since this
- includes evaluating watchpoints, things will come to a
- stop in the correct manner. */
-
- if (debug_infrun)
- fprintf_unfiltered (gdb_stdlog, "infrun: STOPPED_BY_WATCHPOINT\n");
- remove_breakpoints ();
+ 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. */
+
+ if (!HAVE_STEPPABLE_WATCHPOINT)
+ remove_breakpoints ();
registers_changed ();
target_resume (ecs->ptid, 1, TARGET_SIGNAL_0); /* Single step */
-
ecs->waiton_ptid = ecs->ptid;
- ecs->wp = &(ecs->ws);
- ecs->infwait_state = infwait_nonstep_watch_state;
+ if (HAVE_STEPPABLE_WATCHPOINT)
+ ecs->infwait_state = infwait_step_watch_state;
+ else
+ ecs->infwait_state = infwait_nonstep_watch_state;
prepare_to_wait (ecs);
return;
}
- /* It may be possible to simply continue after a watchpoint. */
- if (HAVE_CONTINUABLE_WATCHPOINT)
- stopped_by_watchpoint = STOPPED_BY_WATCHPOINT (ecs->ws);
-
ecs->stop_func_start = 0;
ecs->stop_func_end = 0;
ecs->stop_func_name = 0;
&ecs->stop_func_start, &ecs->stop_func_end);
ecs->stop_func_start
+= gdbarch_deprecated_function_start_offset (current_gdbarch);
- ecs->another_trap = 0;
+ ecs->stepping_over_breakpoint = 0;
bpstat_clear (&stop_bpstat);
stop_step = 0;
- stop_stack_dummy = 0;
stop_print_frame = 1;
ecs->random_signal = 0;
stopped_by_random_signal = 0;
if (stop_signal == TARGET_SIGNAL_TRAP
- && trap_expected
+ && stepping_over_breakpoint
&& gdbarch_single_step_through_delay_p (current_gdbarch)
&& currently_stepping (ecs))
{
- /* We're trying to step of a breakpoint. Turns out that we're
+ /* 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 user issued a continue when stopped at a breakpoint.
Set up for another trap and get out of here. */
- ecs->another_trap = 1;
+ ecs->stepping_over_breakpoint = 1;
keep_going (ecs);
return;
}
/* 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->another_trap,
- making sure we single-step again before breakpoints are
- re-inserted. */
- ecs->another_trap = 1;
+ case, don't decide that here, just set
+ ecs->stepping_over_breakpoint, making sure we
+ single-step again before breakpoints are re-inserted. */
+ ecs->stepping_over_breakpoint = 1;
}
}
The alternatives are:
1) break; to really stop and return to the debugger,
2) drop through to start up again
- (set ecs->another_trap to 1 to single step once)
+ (set ecs->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. */
stack. */
if (stop_signal == TARGET_SIGNAL_TRAP
- || (breakpoints_inserted
+ || (breakpoint_inserted_here_p (stop_pc)
&& (stop_signal == TARGET_SIGNAL_ILL
|| stop_signal == TARGET_SIGNAL_SEGV
|| stop_signal == TARGET_SIGNAL_EMT))
- || stop_soon == STOP_QUIETLY || stop_soon == STOP_QUIETLY_NO_SIGSTOP)
+ || stop_soon == STOP_QUIETLY || stop_soon == STOP_QUIETLY_NO_SIGSTOP
+ || stop_soon == STOP_QUIETLY_REMOTE)
{
if (stop_signal == TARGET_SIGNAL_TRAP && stop_after_trap)
{
/* This is originated from start_remote(), start_inferior() and
shared libraries hook functions. */
- if (stop_soon == STOP_QUIETLY)
+ if (stop_soon == STOP_QUIETLY || stop_soon == STOP_QUIETLY_REMOTE)
{
if (debug_infrun)
fprintf_unfiltered (gdb_stdlog, "infrun: quietly stopped\n");
return;
}
- /* Don't even think about breakpoints if just proceeded over a
- breakpoint. */
- if (stop_signal == TARGET_SIGNAL_TRAP && trap_expected)
- {
- if (debug_infrun)
- fprintf_unfiltered (gdb_stdlog, "infrun: trap expected\n");
- bpstat_clear (&stop_bpstat);
- }
- else
- {
- /* See if there is a breakpoint at the current PC. */
- stop_bpstat = bpstat_stop_status (stop_pc, ecs->ptid,
- stopped_by_watchpoint);
-
- /* Following in case break condition called a
- function. */
- stop_print_frame = 1;
- }
+ /* See if there is a breakpoint at the current PC. */
+ stop_bpstat = bpstat_stop_status (stop_pc, ecs->ptid);
+
+ /* Following in case break condition called a
+ function. */
+ stop_print_frame = 1;
/* NOTE: cagney/2003-03-29: These two checks for a random signal
at one stage in the past included checks for an inferior
if (stop_signal == TARGET_SIGNAL_TRAP)
ecs->random_signal
= !(bpstat_explains_signal (stop_bpstat)
- || trap_expected
+ || stepping_over_breakpoint
|| (step_range_end && step_resume_breakpoint == NULL));
else
{
stop_signal = TARGET_SIGNAL_0;
if (prev_pc == read_pc ()
- && !breakpoints_inserted
- && breakpoint_here_p (read_pc ())
+ && stepping_over_breakpoint
&& step_resume_breakpoint == NULL)
{
/* We were just starting a new sequence, attempting to
if (debug_infrun)
fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_SET_LONGJMP_RESUME\n");
disable_longjmp_breakpoint ();
- remove_breakpoints ();
- breakpoints_inserted = 0;
if (!gdbarch_get_longjmp_target_p (current_gdbarch)
|| !gdbarch_get_longjmp_target (current_gdbarch,
get_current_frame (), &jmp_buf_pc))
return;
case BPSTAT_WHAT_CLEAR_LONGJMP_RESUME:
- case BPSTAT_WHAT_CLEAR_LONGJMP_RESUME_SINGLE:
if (debug_infrun)
fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_CLEAR_LONGJMP_RESUME\n");
- remove_breakpoints ();
- breakpoints_inserted = 0;
disable_longjmp_breakpoint ();
ecs->handling_longjmp = 0; /* FIXME */
- if (what.main_action == BPSTAT_WHAT_CLEAR_LONGJMP_RESUME)
- break;
- /* else fallthrough */
+ break;
case BPSTAT_WHAT_SINGLE:
if (debug_infrun)
fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_SINGLE\n");
- if (breakpoints_inserted)
- remove_breakpoints ();
- breakpoints_inserted = 0;
- ecs->another_trap = 1;
+ ecs->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;
were trying to single-step off a breakpoint. Go back
to doing that. */
ecs->step_after_step_resume_breakpoint = 0;
- remove_breakpoints ();
- breakpoints_inserted = 0;
- ecs->another_trap = 1;
+ ecs->stepping_over_breakpoint = 1;
keep_going (ecs);
return;
}
{
if (debug_infrun)
fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_CHECK_SHLIBS\n");
- /* Remove breakpoints, we eventually want to step over the
- shlib event breakpoint, and SOLIB_ADD might adjust
- breakpoint addresses via breakpoint_re_set. */
- if (breakpoints_inserted)
- remove_breakpoints ();
- breakpoints_inserted = 0;
/* Check for any newly added shared libraries if we're
supposed to be adding them automatically. Switch
#endif
target_terminal_inferior ();
- /* Try to reenable shared library breakpoints, additional
- code segments in shared libraries might be mapped in now. */
- re_enable_breakpoints_in_shlibs ();
-
/* 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
/* Be sure to lift all breakpoints, so the inferior does
actually step past this point... */
- ecs->another_trap = 1;
+ ecs->stepping_over_breakpoint = 1;
break;
}
else
{
/* We want to step over this breakpoint, then keep going. */
- ecs->another_trap = 1;
+ ecs->stepping_over_breakpoint = 1;
break;
}
}
{
if (debug_infrun)
fprintf_unfiltered (gdb_stdlog, "infrun: stepping in dynamic linker\n");
- ecs->another_trap = 1;
+ ecs->stepping_over_breakpoint = 1;
keep_going (ecs);
return;
}
new line in mid-statement, we continue stepping. This makes
things like for(;;) statements work better.) */
- if (ecs->stop_func_end && ecs->sal.end >= ecs->stop_func_end)
- {
- /* If this is the last line of the function, don't keep stepping
- (it would probably step us out of the function).
- This is particularly necessary for a one-line function,
- in which after skipping the prologue we better stop even though
- we will be in mid-line. */
- if (debug_infrun)
- fprintf_unfiltered (gdb_stdlog, "infrun: stepped to a different function\n");
- stop_step = 1;
- print_stop_reason (END_STEPPING_RANGE, 0);
- stop_stepping (ecs);
- return;
- }
step_range_start = ecs->sal.pc;
step_range_end = ecs->sal.end;
step_frame_id = get_frame_id (get_current_frame ());
function. Fortunately, those days are nearly upon us. */
#endif
{
- struct frame_id current_frame = get_frame_id (get_current_frame ());
- if (!(frame_id_inner (current_frame, step_frame_id)))
+ struct frame_info *frame = get_current_frame ();
+ struct frame_id current_frame = get_frame_id (frame);
+ if (!(frame_id_inner (get_frame_arch (frame), current_frame,
+ step_frame_id)))
step_frame_id = current_frame;
}
{
return ((!ecs->handling_longjmp
&& ((step_range_end && step_resume_breakpoint == NULL)
- || trap_expected))
+ || stepping_over_breakpoint))
|| ecs->stepping_through_solib_after_catch
|| bpstat_should_step ());
}
step_resume_breakpoint = set_momentary_breakpoint (sr_sal, sr_id,
bp_step_resume);
- if (breakpoints_inserted)
- insert_breakpoints ();
}
/* Insert a "step-resume breakpoint" at RETURN_FRAME.pc. This is used
{
struct symtab_and_line sr_sal;
+ gdb_assert (return_frame != NULL);
init_sal (&sr_sal); /* initialize to zeros */
sr_sal.pc = gdbarch_addr_bits_remove
/* If we did not do break;, it means we should keep running the
inferior and not return to debugger. */
- if (trap_expected && stop_signal != TARGET_SIGNAL_TRAP)
+ if (stepping_over_breakpoint && stop_signal != TARGET_SIGNAL_TRAP)
{
/* We took a signal (which we are supposed to pass through to
the inferior, else we'd have done a break above) and we
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! */
+ We're going to run this baby now!
- if (!breakpoints_inserted && !ecs->another_trap)
+ 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->stepping_over_breakpoint)
{
+ remove_breakpoints ();
+ }
+ else
+ {
+ struct gdb_exception e;
/* Stop stepping when inserting breakpoints
has failed. */
- if (insert_breakpoints () != 0)
+ TRY_CATCH (e, RETURN_MASK_ERROR)
+ {
+ insert_breakpoints ();
+ }
+ if (e.reason < 0)
{
stop_stepping (ecs);
return;
}
- breakpoints_inserted = 1;
}
- trap_expected = ecs->another_trap;
+ stepping_over_breakpoint = ecs->stepping_over_breakpoint;
/* Do not deliver SIGNAL_TRAP (except when the user explicitly
specifies that such a signal should be delivered to the
{
target_terminal_ours_for_output ();
printf_filtered (_("[Switching to %s]\n"),
- target_pid_or_tid_to_str (inferior_ptid));
+ target_pid_to_str (inferior_ptid));
previous_inferior_ptid = inferior_ptid;
}
gdbarch_decr_pc_after_break needs to just go away. */
deprecated_update_frame_pc_hack (get_current_frame (), read_pc ());
- if (target_has_execution && breakpoints_inserted)
+ if (!breakpoints_always_inserted_mode () && target_has_execution)
{
if (remove_breakpoints ())
{
Further execution is probably impossible.\n"));
}
}
- breakpoints_inserted = 0;
-
- /* 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 (stop_bpstat);
/* If an auto-display called a function and that got a signal,
delete that auto-display to avoid an infinite recursion. */
switch (bpstat_ret)
{
case PRINT_UNKNOWN:
+ /* If we had hit a shared library event breakpoint,
+ bpstat_print would print out this message. If we hit
+ an OS-level shared library event, do the same
+ thing. */
+ if (last.kind == TARGET_WAITKIND_LOADED)
+ {
+ printf_filtered (_("Stopped due to shared library event\n"));
+ source_flag = SRC_LINE; /* something bogus */
+ do_frame_printing = 0;
+ break;
+ }
+
/* 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. */
done:
annotate_stopped ();
observer_notify_normal_stop (stop_bpstat);
+ /* 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 (stop_bpstat);
}
static int
int stop_step;
int stop_stack_dummy;
int stopped_by_random_signal;
- int trap_expected;
+ int stepping_over_breakpoint;
CORE_ADDR step_range_start;
CORE_ADDR step_range_end;
struct frame_id step_frame_id;
inf_status->stop_step = stop_step;
inf_status->stop_stack_dummy = stop_stack_dummy;
inf_status->stopped_by_random_signal = stopped_by_random_signal;
- inf_status->trap_expected = trap_expected;
+ inf_status->stepping_over_breakpoint = stepping_over_breakpoint;
inf_status->step_range_start = step_range_start;
inf_status->step_range_end = step_range_end;
inf_status->step_frame_id = step_frame_id;
stop_step = inf_status->stop_step;
stop_stack_dummy = inf_status->stop_stack_dummy;
stopped_by_random_signal = inf_status->stopped_by_random_signal;
- trap_expected = inf_status->trap_expected;
+ stepping_over_breakpoint = inf_status->stepping_over_breakpoint;
step_range_start = inf_status->step_range_start;
step_range_end = inf_status->step_range_end;
step_frame_id = inf_status->step_frame_id;
projects / binutils.git / blobdiff