Re: RFC: next/finish/etc -vs- exceptions

Tom Tromey
2009-07-24T16:55:14Z

Here is a new revision of this patch.

I addressed most of the comments made about the earlier versions. It
now uses frame ids and it includes a test for a throw from a signal
handler (written in Java, since that was simplest).

I didn't address Doug's comment about issuing a warning when the needed
debug hook cannot be found. It seems strange to do this in general,
because exceptions are not used by all programs.

I also haven't yet tried to make the longjmp code work like the
exception code. I'd like to see Pedro's glibc/longjmp fix go in first,
so I can have a reasonable chance of testing any changes here.

In order to use this new feature you must use a new gcc -- one that has
the necessary debug function in the unwinder.

Built and regtested on x86-64 (compile farm). This compiler doesn't
have the new hook, so I also tested it locally (x86 F11) using a svn
trunk gcc.

Let me know what you think.

Tom

2009-07-24 Tom Tromey <tromey@redhat.com>

PR c++/9593:
* infrun.c (handle_inferior_event): Handle exception breakpoints.
(insert_exception_resume_breakpoint): New function.
(check_exception_resume): Likewise.
(keep_going): Print exception when debugging.
* inferior.h: (delete_longjmp_breakpoint_cleanup): Declare.
* infcmd.c (delete_longjmp_breakpoint_cleanup): No longer static.
(step_1): Set initiating_frame.
(until_next_continuation): New function.
(until_next_command): Set initiating_frame. Make a continuation.
(finish_command_continuation): Call delete_longjmp_breakpoint.
(finish_forward): Set initiating_frame.
* gdbthread.h (struct thread_info) <initiating_frame>: New field.
* breakpoint.h (enum bptype) <bp_exception, bp_exception_resume,
bp_exception_master>: New constants.
(struct bpstat_what) <is_longjmp>: New field.
* breakpoint.c (update_breakpoints_after_exec): Handle
bp_exception, bp_exception_resume, and bp_exception_master. Call
create_exception_master_breakpoint.
(print_it_typical): Handle bp_exception, bp_exception_resume, and
bp_exception_master.
(bpstat_stop_status): Likewise.
(print_one_breakpoint_location): Likewise.
(allocate_bp_location): Likewise.
(mention): Likewise.
(breakpoint_re_set_one): Likewise.
(delete_command): Likewise.
(bpstat_what): Likewise. Set 'is_longjmp' field.
(set_longjmp_breakpoint): Handle bp_exception_master.
(delete_longjmp_breakpoint): Handle bp_exception.
(create_exception_master_breakpoint): New function.
(struct until_break_command_continuation_args) <thread_num>: New
field.
(until_break_command_continuation): Call
delete_longjmp_breakpoint.
(until_break_command): Call set_exception_breakpoint.
(breakpoint_re_set): Call create_exception_master_breakpoint.

2009-07-24 Tom Tromey <tromey@redhat.com>

* gdb.java/jnpe.java: New file.
* gdb.java/jnpe.exp: New file.
* gdb.cp/gdb9593.cc: New file.
* gdb.cp/gdb9593.exp: New file.
* gdb.cp/Makefile.in (EXECUTABLES): Add gdb9593.

diff --git a/gdb/breakpoint.c b/gdb/breakpoint.c
index 3a18c8f..621e527 100644
--- a/gdb/breakpoint.c
+++ b/gdb/breakpoint.c
@@ -1548,6 +1548,36 @@ create_longjmp_master_breakpoint (char *func_name)
update_global_location_list (1);
}

+/* Install a master breakpoint on the unwinder's debug hook. */
+
+void
+create_exception_master_breakpoint (void)
+{
+ struct objfile *objfile;
+
+ ALL_OBJFILES (objfile)
+ {
+ struct minimal_symbol *debug_hook;
+
+ debug_hook = lookup_minimal_symbol_text ("_Unwind_DebugHook", objfile);
+ if (debug_hook != NULL)
+ {
+ CORE_ADDR pc;
+ struct breakpoint *b;
+
+ pc = find_function_start_pc (get_objfile_arch (objfile),
+ SYMBOL_VALUE_ADDRESS (debug_hook),
+ SYMBOL_OBJ_SECTION (debug_hook));
+ b = create_internal_breakpoint (get_objfile_arch (objfile),
+ pc, bp_exception_master);
+ b->addr_string = xstrdup ("_Unwind_DebugHook");
+ b->enable_state = bp_disabled;
+ }
+ }
+
+ update_global_location_list (1);
+}
+
void
update_breakpoints_after_exec (void)
{
@@ -1578,7 +1608,7 @@ update_breakpoints_after_exec (void)
/* Thread event breakpoints must be set anew after an exec(),
as must overlay event and longjmp master breakpoints. */
if (b->type == bp_thread_event || b->type == bp_overlay_event
- || b->type == bp_longjmp_master)
+ || b->type == bp_longjmp_master || b->type == bp_exception_master)
{
delete_breakpoint (b);
continue;
@@ -1593,7 +1623,8 @@ update_breakpoints_after_exec (void)

/* Longjmp and longjmp-resume breakpoints are also meaningless
after an exec. */
- if (b->type == bp_longjmp || b->type == bp_longjmp_resume)
+ if (b->type == bp_longjmp || b->type == bp_longjmp_resume
+ || b->type == bp_exception || b->type == bp_exception_resume)
{
delete_breakpoint (b);
continue;
@@ -1654,6 +1685,7 @@ update_breakpoints_after_exec (void)
create_longjmp_master_breakpoint ("_longjmp");
create_longjmp_master_breakpoint ("siglongjmp");
create_longjmp_master_breakpoint ("_siglongjmp");
+ create_exception_master_breakpoint ();
}

int
@@ -2482,6 +2514,12 @@ print_it_typical (bpstat bs)
result = PRINT_NOTHING;
break;

+ case bp_exception_master:
+ /* These should never be enabled. */
+ printf_filtered (_("Exception Master Breakpoint: gdb should not stop!\n"));
+ result = PRINT_NOTHING;
+ break;
+
case bp_watchpoint:
case bp_hardware_watchpoint:
annotate_watchpoint (b->number);
@@ -2569,6 +2607,8 @@ print_it_typical (bpstat bs)
case bp_none:
case bp_longjmp:
case bp_longjmp_resume:
+ case bp_exception:
+ case bp_exception_resume:
case bp_step_resume:
case bp_watchpoint_scope:
case bp_call_dummy:
@@ -3178,7 +3218,7 @@ bpstat_stop_status (CORE_ADDR bp_addr, ptid_t ptid)
continue;

if (b->type == bp_thread_event || b->type == bp_overlay_event
- || b->type == bp_longjmp_master)
+ || b->type == bp_longjmp_master || b->type == bp_exception_master)
/* We do not stop for these. */
bs->stop = 0;
else
@@ -3394,6 +3434,7 @@ bpstat_what (bpstat bs)
struct bpstat_what retval;

retval.call_dummy = 0;
+ retval.is_longjmp = 0;
for (; bs != NULL; bs = bs->next)
{
enum class bs_class = no_effect;
@@ -3440,10 +3481,15 @@ bpstat_what (bpstat bs)
bs_class = no_effect;
break;
case bp_longjmp:
+ case bp_exception:
bs_class = long_jump;
+ retval.is_longjmp = bs->breakpoint_at->owner->type == bp_longjmp;
break;
case bp_longjmp_resume:
+ case bp_exception_resume:
bs_class = long_resume;
+ retval.is_longjmp
+ = bs->breakpoint_at->owner->type == bp_longjmp_resume;
break;
case bp_step_resume:
if (bs->stop)
@@ -3463,6 +3509,7 @@ bpstat_what (bpstat bs)
case bp_thread_event:
case bp_overlay_event:
case bp_longjmp_master:
+ case bp_exception_master:
bs_class = bp_nostop;
break;
case bp_catchpoint:
@@ -3584,6 +3631,8 @@ print_one_breakpoint_location (struct breakpoint *b,
{bp_access_watchpoint, "acc watchpoint"},
{bp_longjmp, "longjmp"},
{bp_longjmp_resume, "longjmp resume"},
+ {bp_exception, "exception"},
+ {bp_exception_resume, "exception resume"},
{bp_step_resume, "step resume"},
{bp_watchpoint_scope, "watchpoint scope"},
{bp_call_dummy, "call dummy"},
@@ -3591,6 +3640,7 @@ print_one_breakpoint_location (struct breakpoint *b,
{bp_thread_event, "thread events"},
{bp_overlay_event, "overlay events"},
{bp_longjmp_master, "longjmp master"},
+ {bp_exception_master, "exception master"},
{bp_catchpoint, "catchpoint"},
{bp_tracepoint, "tracepoint"},
};
@@ -3713,6 +3763,8 @@ print_one_breakpoint_location (struct breakpoint *b,
case bp_finish:
case bp_longjmp:
case bp_longjmp_resume:
+ case bp_exception:
+ case bp_exception_resume:
case bp_step_resume:
case bp_watchpoint_scope:
case bp_call_dummy:
@@ -3720,6 +3772,7 @@ print_one_breakpoint_location (struct breakpoint *b,
case bp_thread_event:
case bp_overlay_event:
case bp_longjmp_master:
+ case bp_exception_master:
case bp_tracepoint:
if (opts.addressprint)
{
@@ -4356,6 +4409,8 @@ allocate_bp_location (struct breakpoint *bpt)
case bp_finish:
case bp_longjmp:
case bp_longjmp_resume:
+ case bp_exception:
+ case bp_exception_resume:
case bp_step_resume:
case bp_watchpoint_scope:
case bp_call_dummy:
@@ -4363,6 +4418,7 @@ allocate_bp_location (struct breakpoint *bpt)
case bp_thread_event:
case bp_overlay_event:
case bp_longjmp_master:
+ case bp_exception_master:
loc->loc_type = bp_loc_software_breakpoint;
break;
case bp_hardware_breakpoint:
@@ -4540,8 +4596,7 @@ make_breakpoint_permanent (struct breakpoint *b)
}

/* Call this routine when stepping and nexting to enable a breakpoint
- if we do a longjmp() in THREAD. When we hit that breakpoint, call
- set_longjmp_resume_breakpoint() to figure out where we are going. */
+ if we do a longjmp() or 'throw' in THREAD. */

void
set_longjmp_breakpoint (int thread)
@@ -4553,10 +4608,10 @@ set_longjmp_breakpoint (int thread)
longjmp "master" breakpoints. Here, we simply create momentary
clones of those and enable them for the requested thread. */
ALL_BREAKPOINTS_SAFE (b, temp)
- if (b->type == bp_longjmp_master)
+ if (b->type == bp_longjmp_master || b->type == bp_exception_master)
{
struct breakpoint *clone = clone_momentary_breakpoint (b);
- clone->type = bp_longjmp;
+ clone->type = b->type == bp_longjmp_master ? bp_longjmp : bp_exception;
clone->thread = thread;
}
}
@@ -4568,7 +4623,7 @@ delete_longjmp_breakpoint (int thread)
struct breakpoint *b, *temp;

ALL_BREAKPOINTS_SAFE (b, temp)
- if (b->type == bp_longjmp)
+ if (b->type == bp_longjmp || b->type == bp_exception)
{
if (b->thread == thread)
delete_breakpoint (b);
@@ -5273,6 +5328,8 @@ mention (struct breakpoint *b)
case bp_finish:
case bp_longjmp:
case bp_longjmp_resume:
+ case bp_exception:
+ case bp_exception_resume:
case bp_step_resume:
case bp_call_dummy:
case bp_watchpoint_scope:
@@ -5280,6 +5337,7 @@ mention (struct breakpoint *b)
case bp_thread_event:
case bp_overlay_event:
case bp_longjmp_master:
+ case bp_exception_master:
break;
}

@@ -6572,6 +6630,7 @@ struct until_break_command_continuation_args
{
struct breakpoint *breakpoint;
struct breakpoint *breakpoint2;
+ int thread_num;
};

/* This function is called by fetch_inferior_event via the
@@ -6586,6 +6645,7 @@ until_break_command_continuation (void *arg)
delete_breakpoint (a->breakpoint);
if (a->breakpoint2)
delete_breakpoint (a->breakpoint2);
+ delete_longjmp_breakpoint (a->thread_num);
}

void
@@ -6597,6 +6657,8 @@ until_break_command (char *arg, int from_tty, int anywhere)
struct breakpoint *breakpoint;
struct breakpoint *breakpoint2 = NULL;
struct cleanup *old_chain;
+ int thread;
+ struct thread_info *tp;

clear_proceed_status ();

@@ -6635,6 +6697,9 @@ until_break_command (char *arg, int from_tty, int anywhere)

old_chain = make_cleanup_delete_breakpoint (breakpoint);

+ tp = inferior_thread ();
+ thread = tp->num;
+
/* Keep within the current frame, or in frames called by the current
one. */

@@ -6647,6 +6712,10 @@ until_break_command (char *arg, int from_tty, int anywhere)
frame_unwind_caller_id (frame),
bp_until);
make_cleanup_delete_breakpoint (breakpoint2);
+
+ set_longjmp_breakpoint (thread);
+ tp->initiating_frame = frame_unwind_caller_id (frame);
+ make_cleanup (delete_longjmp_breakpoint_cleanup, &thread);
}

proceed (-1, TARGET_SIGNAL_DEFAULT, 0);
@@ -6663,6 +6732,7 @@ until_break_command (char *arg, int from_tty, int anywhere)

args->breakpoint = breakpoint;
args->breakpoint2 = breakpoint2;
+ args->thread_num = thread;

discard_cleanups (old_chain);
add_continuation (inferior_thread (),
@@ -7588,6 +7658,7 @@ delete_command (char *arg, int from_tty)
&& b->type != bp_thread_event
&& b->type != bp_overlay_event
&& b->type != bp_longjmp_master
+ && b->type != bp_exception_master
&& b->number >= 0)
{
breaks_to_delete = 1;
@@ -7606,6 +7677,7 @@ delete_command (char *arg, int from_tty)
&& b->type != bp_thread_event
&& b->type != bp_overlay_event
&& b->type != bp_longjmp_master
+ && b->type != bp_exception_master
&& b->number >= 0)
delete_breakpoint (b);
}
@@ -7904,6 +7976,7 @@ breakpoint_re_set_one (void *bint)
reset later by breakpoint_re_set. */
case bp_overlay_event:
case bp_longjmp_master:
+ case bp_exception_master:
delete_breakpoint (b);
break;

@@ -7926,6 +7999,8 @@ breakpoint_re_set_one (void *bint)
case bp_step_resume:
case bp_longjmp:
case bp_longjmp_resume:
+ case bp_exception:
+ case bp_exception_resume:
break;
}

@@ -7959,6 +8034,7 @@ breakpoint_re_set (void)
create_longjmp_master_breakpoint ("_longjmp");
create_longjmp_master_breakpoint ("siglongjmp");
create_longjmp_master_breakpoint ("_siglongjmp");
+ create_exception_master_breakpoint ();
}
\f
/* Reset the thread number of this breakpoint:
diff --git a/gdb/breakpoint.h b/gdb/breakpoint.h
index 6731e68..86afc64 100644
--- a/gdb/breakpoint.h
+++ b/gdb/breakpoint.h
@@ -55,6 +55,13 @@ enum bptype
bp_longjmp, /* secret breakpoint to find longjmp() */
bp_longjmp_resume, /* secret breakpoint to escape longjmp() */

+ /* An internal breakpoint that is installed on the unwinder's
+ debug hook. */
+ bp_exception,
+ /* An internal breakpoint that is set at the point where an
+ exception will land. */
+ bp_exception_resume,
+
/* Used by wait_for_inferior for stepping over subroutine calls, for
stepping over signal handlers, and for skipping prologues. */
bp_step_resume,
@@ -117,6 +124,9 @@ enum bptype

bp_longjmp_master,

+ /* Like bp_longjmp_master, but for exceptions. */
+ bp_exception_master,
+
bp_catchpoint,

bp_tracepoint,
@@ -561,6 +571,10 @@ struct bpstat_what
continuing from a call dummy without popping the frame is not a
useful one). */
int call_dummy;
+
+ /* Used for BPSTAT_WHAT_SET_LONGJMP_RESUME. True if we are
+ handling a longjmp, false if we are handling an exception. */
+ int is_longjmp;
};

/* The possible return values for print_bpstat, print_it_normal,
diff --git a/gdb/gdbthread.h b/gdb/gdbthread.h
index 79d33fe..4f76dc2 100644
--- a/gdb/gdbthread.h
+++ b/gdb/gdbthread.h
@@ -185,6 +185,10 @@ struct thread_info
/* True if this thread has been explicitly requested to stop. */
int stop_requested;

+ /* The initiating frame of a nexting operation, used for deciding
+ which exceptions to intercept. */
+ struct frame_id initiating_frame;
+
/* Private data used by the target vector implementation. */
struct private_thread_info *private;
};
diff --git a/gdb/infcmd.c b/gdb/infcmd.c
index 9e98290..fab1892 100644
--- a/gdb/infcmd.c
+++ b/gdb/infcmd.c
@@ -801,7 +801,7 @@ nexti_command (char *count_string, int from_tty)
step_1 (1, 1, count_string);
}

-static void
+void
delete_longjmp_breakpoint_cleanup (void *arg)
{
int thread = * (int *) arg;
@@ -841,10 +841,13 @@ step_1 (int skip_subroutines, int single_inst, char *count_string)

if (!single_inst || skip_subroutines) /* leave si command alone */
{
+ struct thread_info *tp = inferior_thread ();
+
if (in_thread_list (inferior_ptid))
thread = pid_to_thread_id (inferior_ptid);

set_longjmp_breakpoint (thread);
+ tp->initiating_frame = get_frame_id (get_current_frame ());

make_cleanup (delete_longjmp_breakpoint_cleanup, &thread);
}
@@ -1193,6 +1196,15 @@ signal_command (char *signum_exp, int from_tty)
proceed ((CORE_ADDR) -1, oursig, 0);
}

+/* A continuation callback for until_next_command. */
+
+static void
+until_next_continuation (void *arg)
+{
+ struct thread_info *tp = arg;
+ delete_longjmp_breakpoint (tp->num);
+}
+
/* Proceed until we reach a different source line with pc greater than
our current one or exit the function. We skip calls in both cases.

@@ -1209,6 +1221,8 @@ until_next_command (int from_tty)
struct symbol *func;
struct symtab_and_line sal;
struct thread_info *tp = inferior_thread ();
+ int thread = tp->num;
+ struct cleanup *old_chain;

clear_proceed_status ();
set_step_frame ();
@@ -1244,7 +1258,19 @@ until_next_command (int from_tty)

tp->step_multi = 0; /* Only one call to proceed */

+ set_longjmp_breakpoint (thread);
+ tp->initiating_frame = get_frame_id (frame);
+ old_chain = make_cleanup (delete_longjmp_breakpoint_cleanup, &thread);
+
proceed ((CORE_ADDR) -1, TARGET_SIGNAL_DEFAULT, 1);
+
+ if (target_can_async_p () && is_running (inferior_ptid))
+ {
+ discard_cleanups (old_chain);
+ add_continuation (tp, until_next_continuation, tp, NULL);
+ }
+ else
+ do_cleanups (old_chain);
}

static void
@@ -1421,6 +1447,7 @@ finish_command_continuation (void *arg)
if (bs != NULL && tp->proceed_to_finish)
observer_notify_normal_stop (bs, 1 /* print frame */);
delete_breakpoint (a->breakpoint);
+ delete_longjmp_breakpoint (inferior_thread ()->num);
}

static void
@@ -1504,6 +1531,7 @@ finish_forward (struct symbol *function, struct frame_info *frame)
struct breakpoint *breakpoint;
struct cleanup *old_chain;
struct finish_command_continuation_args *cargs;
+ int thread = tp->num;

sal = find_pc_line (get_frame_pc (frame), 0);
sal.pc = get_frame_pc (frame);
@@ -1514,6 +1542,10 @@ finish_forward (struct symbol *function, struct frame_info *frame)

old_chain = make_cleanup_delete_breakpoint (breakpoint);

+ set_longjmp_breakpoint (thread);
+ tp->initiating_frame = get_frame_id (frame);
+ make_cleanup (delete_longjmp_breakpoint_cleanup, &thread);
+
tp->proceed_to_finish = 1; /* We want stop_registers, please... */
proceed ((CORE_ADDR) -1, TARGET_SIGNAL_DEFAULT, 0);

diff --git a/gdb/inferior.h b/gdb/inferior.h
index 7312e51..d4eae88 100644
--- a/gdb/inferior.h
+++ b/gdb/inferior.h
@@ -272,6 +272,8 @@ extern void interrupt_target_command (char *args, int from_tty);

extern void interrupt_target_1 (int all_threads);

+extern void delete_longjmp_breakpoint_cleanup (void *arg);
+
extern void detach_command (char *, int);

extern void notice_new_inferior (ptid_t, int, int);
diff --git a/gdb/infrun.c b/gdb/infrun.c
index 9f6cfc9..bccc00c 100644
--- a/gdb/infrun.c
+++ b/gdb/infrun.c
@@ -45,6 +45,8 @@
#include "language.h"
#include "solib.h"
#include "main.h"
+#include "dictionary.h"
+#include "block.h"
#include "gdb_assert.h"
#include "mi/mi-common.h"
#include "event-top.h"
@@ -1768,6 +1770,8 @@ static void insert_step_resume_breakpoint_at_sal (struct gdbarch *gdbarch,
struct symtab_and_line sr_sal,
struct frame_id sr_id);
static void insert_longjmp_resume_breakpoint (struct gdbarch *, CORE_ADDR);
+static void check_exception_resume (struct execution_control_state *,
+ struct frame_info *, struct symbol *);

static void stop_stepping (struct execution_control_state *ecs);
static void prepare_to_wait (struct execution_control_state *ecs);
@@ -3405,23 +3409,33 @@ process_event_stop_test:

ecs->event_thread->stepping_over_breakpoint = 1;

- if (!gdbarch_get_longjmp_target_p (gdbarch)
- || !gdbarch_get_longjmp_target (gdbarch, frame, &jmp_buf_pc))
+ if (what.is_longjmp)
{
- if (debug_infrun)
- fprintf_unfiltered (gdb_stdlog, "\
+ 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;
- }
+ keep_going (ecs);
+ return;
+ }

- /* We're going to replace the current step-resume breakpoint
- with a longjmp-resume breakpoint. */
- delete_step_resume_breakpoint (ecs->event_thread);
+ /* We're going to replace the current step-resume breakpoint
+ with a longjmp-resume breakpoint. */
+ delete_step_resume_breakpoint (ecs->event_thread);

- /* Insert a breakpoint at resume address. */
- insert_longjmp_resume_breakpoint (gdbarch, jmp_buf_pc);
+ /* Insert a breakpoint at resume address. */
+ insert_longjmp_resume_breakpoint (gdbarch, jmp_buf_pc);
+ }
+ else
+ {
+ struct symbol *func = get_frame_function (frame);

+ if (func)
+ check_exception_resume (ecs, frame, func);
+ }
keep_going (ecs);
return;

@@ -3433,6 +3447,53 @@ infrun: BPSTAT_WHAT_SET_LONGJMP_RESUME (!gdbarch_get_longjmp_target)\n");
gdb_assert (ecs->event_thread->step_resume_breakpoint != NULL);
delete_step_resume_breakpoint (ecs->event_thread);

+ if (!what.is_longjmp)
+ {
+ /* There are several cases to consider.
+
+ 1. The initiating frame no longer exists. In this case
+ we must stop, because the exception has gone too far.
+
+ 2. The initiating frame exists, and is the same as the
+ current frame.
+
+ 2.1. If we are stepping, defer to the stepping logic.
+
+ 2.2. Otherwise, we are not stepping, so we are doing a
+ "finish" and we have reached the calling frame. So,
+ stop.
+
+ 3. The initiating frame exists and is different from
+ the current frame. This means the exception has been
+ caught beneath the initiating frame, so keep going. */
+ struct frame_info *init_frame
+ = frame_find_by_id (ecs->event_thread->initiating_frame);
+ if (init_frame)
+ {
+ struct frame_id current_id
+ = get_frame_id (get_current_frame ());
+ if (frame_id_eq (current_id,
+ ecs->event_thread->initiating_frame))
+ {
+ if (ecs->event_thread->step_range_start)
+ {
+ /* Case 2.1. */
+ break;
+ }
+ else
+ {
+ /* Case 2.2: fall through. */
+ }
+ }
+ else
+ {
+ /* Case 3. */
+ keep_going (ecs);
+ return;
+ }
+ }
+ }
+
ecs->event_thread->stop_step = 1;
print_stop_reason (END_STEPPING_RANGE, 0);
stop_stepping (ecs);
@@ -4377,6 +4438,96 @@ insert_longjmp_resume_breakpoint (struct gdbarch *gdbarch, CORE_ADDR pc)
set_momentary_breakpoint_at_pc (gdbarch, pc, bp_longjmp_resume);
}

+/* Insert an exception resume breakpoint. TP is the thread throwing
+ the exception. The block B is the block of the unwinder debug hook
+ function. FRAME is the frame corresponding to the call to this
+ function. SYM is the symbol of the function argument holding the
+ target PC of the exception. */
+
+static void
+insert_exception_resume_breakpoint (struct thread_info *tp,
+ struct block *b,
+ struct frame_info *frame,
+ struct symbol *sym)
+{
+ struct gdb_exception e;
+
+ /* We want to ignore errors here. */
+ TRY_CATCH (e, RETURN_MASK_ALL)
+ {
+ struct symbol *vsym;
+ struct value *value;
+ CORE_ADDR handler;
+ struct breakpoint *bp;
+
+ vsym = lookup_symbol (SYMBOL_LINKAGE_NAME (sym), b, VAR_DOMAIN, NULL);
+ value = read_var_value (vsym, frame);
+ handler = value_as_address (value);
+
+ /* We're going to replace the current step-resume breakpoint
+ with an exception-resume breakpoint. */
+ delete_step_resume_breakpoint (tp);
+
+ if (debug_infrun)
+ fprintf_unfiltered (gdb_stdlog,
+ "infrun: exception resume at %lx\n",
+ (unsigned long) handler);
+
+ bp = set_momentary_breakpoint_at_pc (get_frame_arch (frame),
+ handler, bp_exception_resume);
+ inferior_thread ()->step_resume_breakpoint = bp;
+ }
+}
+
+/* This is called when an exception has been intercepted. Check to
+ see whether the exception's destination is of interest, and if so,
+ set an exception resume breakpoint there. */
+
+static void
+check_exception_resume (struct execution_control_state *ecs,
+ struct frame_info *frame, struct symbol *func)
+{
+ struct gdb_exception e;
+
+ TRY_CATCH (e, RETURN_MASK_ALL)
+ {
+ struct block *b;
+ struct dict_iterator iter;
+ struct symbol *sym;
+ int argno = 0;
+
+ /* The exception breakpoint is a thread-specific breakpoint on
+ the unwinder's debug hook, declared as:
+
+ void _Unwind_DebugHook (void *cfa, void *handler);
+
+ The CFA argument indicates the frame to which control is
+ about to be transferred. HANDLER is the destination PC.
+
+ We ignore the CFA and set a temporary breakpoint at HANDLER.
+ This is not extremely efficient but it avoids issues in gdb
+ with computing the DWARF CFA, and it also works even in weird
+ cases such as throwing an exception from inside a signal
+ handler. */
+
+ b = SYMBOL_BLOCK_VALUE (func);
+ ALL_BLOCK_SYMBOLS (b, iter, sym)
+ {
+ if (!SYMBOL_IS_ARGUMENT (sym))
+ continue;
+
+ if (argno == 0)
+ ++argno;
+ else
+ {
+ insert_exception_resume_breakpoint (ecs->event_thread,
+ b, frame, sym);
+ break;
+ }
+ }
+ }
+}
+
static void
stop_stepping (struct execution_control_state *ecs)
{
@@ -4445,6 +4596,8 @@ keep_going (struct execution_control_state *ecs)
}
if (e.reason < 0)
{
+ if (debug_infrun)
+ exception_fprintf (gdb_stdlog, e, "infrun: exception while inserting breakpoints: ");
stop_stepping (ecs);
return;
}
diff --git a/gdb/testsuite/gdb.cp/Makefile.in b/gdb/testsuite/gdb.cp/Makefile.in
index 0a087c7..b4880f2 100644
--- a/gdb/testsuite/gdb.cp/Makefile.in
+++ b/gdb/testsuite/gdb.cp/Makefile.in
@@ -4,7 +4,7 @@ srcdir = @srcdir@
EXECUTABLES = ambiguous annota2 anon-union cplusfuncs cttiadd \
derivation inherit local member-ptr method misc \
overload ovldbreak ref-typ ref-typ2 templates userdef virtfunc namespace \
- ref-types ref-params method2 pr9594 gdb2495
+ ref-types ref-params method2 pr9594 gdb2495 gdb9593

all info install-info dvi install uninstall installcheck check:
@echo "Nothing to be done for $@..."
diff --git a/gdb/testsuite/gdb.cp/gdb9593.cc b/gdb/testsuite/gdb.cp/gdb9593.cc
new file mode 100644
index 0000000..783c962
--- /dev/null
+++ b/gdb/testsuite/gdb.cp/gdb9593.cc
@@ -0,0 +1,180 @@
+/* This testcase is part of GDB, the GNU debugger.
+
+ Copyright 2008, 2009 Free Software Foundation, Inc.
+
+ This program is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation; either version 3 of the License, or
+ (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+#include <iostream>
+
+using namespace std;
+
+class NextOverThrowDerivates
+{
+
+public:
+
+
+ // Single throw an exception in this function.
+ void function1()
+ {
+ throw 20;
+ }
+
+ // Throw an exception in another function.
+ void function2()
+ {
+ function1();
+ }
+
+ // Throw an exception in another function, but handle it
+ // locally.
+ void function3 ()
+ {
+ {
+ try
+ {
+ function1 ();
+ }
+ catch (...)
+ {
+ cout << "Caught and handled function1 exception" << endl;
+ }
+ }
+ }
+
+ void rethrow ()
+ {
+ try
+ {
+ function1 ();
+ }
+ catch (...)
+ {
+ throw;
+ }
+ }
+
+ void finish ()
+ {
+ // We use this to test that a "finish" here does not end up in
+ // this frame, but in the one above.
+ try
+ {
+ function1 ();
+ }
+ catch (int x)
+ {
+ }
+ function1 (); // marker for until
+ }
+
+ void until ()
+ {
+ function1 ();
+ function1 (); // until here
+ }
+
+};
+NextOverThrowDerivates next_cases;
+
+
+int main ()
+{
+ try
+ {
+ next_cases.function1 ();
+ }
+ catch (...)
+ {
+ // Discard
+ }
+
+ try
+ {
+ next_cases.function2 ();
+ }
+ catch (...)
+ {
+ // Discard
+ }
+
+ try
+ {
+ // This is duplicated so we can next over one but step into
+ // another.
+ next_cases.function2 ();
+ }
+ catch (...)
+ {
+ // Discard
+ }
+
+ next_cases.function3 ();
+
+ try
+ {
+ next_cases.rethrow ();
+ }
+ catch (...)
+ {
+ // Discard
+ }
+
+ try
+ {
+ // Another duplicate so we can test "finish".
+ next_cases.function2 ();
+ }
+ catch (...)
+ {
+ // Discard
+ }
+
+ // Another test for "finish".
+ try
+ {
+ next_cases.finish ();
+ }
+ catch (...)
+ {
+ }
+
+ // Test of "until".
+ try
+ {
+ next_cases.finish ();
+ }
+ catch (...)
+ {
+ }
+
+ // Test of "until" with an argument.
+ try
+ {
+ next_cases.until ();
+ }
+ catch (...)
+ {
+ }
+
+ // Test of "advance".
+ try
+ {
+ next_cases.until ();
+ }
+ catch (...)
+ {
+ }
+}
+
diff --git a/gdb/testsuite/gdb.cp/gdb9593.exp b/gdb/testsuite/gdb.cp/gdb9593.exp
new file mode 100644
index 0000000..ee9aeff
--- /dev/null
+++ b/gdb/testsuite/gdb.cp/gdb9593.exp
@@ -0,0 +1,185 @@
+# Copyright 2008, 2009 Free Software Foundation, Inc.
+
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program. If not, see <http://www.gnu.org/licenses/>.
+
+
+if $tracelevel then {
+ strace $tracelevel
+}
+
+if { [skip_cplus_tests] } { continue }
+
+set prms_id 9593
+set bug_id 0
+
+set testfile "gdb9593"
+set srcfile ${testfile}.cc
+set binfile $objdir/$subdir/$testfile
+
+# Create and source the file that provides information about the compiler
+# used to compile the test case.
+if [get_compiler_info ${binfile} "c++"] {
+ untested gdb9593.exp
+ return -1
+}
+
+if { [gdb_compile "${srcdir}/${subdir}/${srcfile}" "${binfile}" executable {debug c++}] != "" } {
+ untested gdb9593.exp
+ return -1
+}
+
+# Some targets can't do function calls, so don't even bother with this
+# test.
+if [target_info exists gdb,cannot_call_functions] {
+ setup_xfail "*-*-*" 9593
+ fail "This target can not call functions"
+ continue
+}
+
+gdb_exit
+gdb_start
+gdb_reinitialize_dir $srcdir/$subdir
+gdb_load ${binfile}
+
+if ![runto_main] then {
+ perror "couldn't run to main"
+ continue
+}
+
+# See whether we have the needed unwinder hooks.
+set ok 1
+gdb_test_multiple "print _Unwind_DebugHook" "check for unwinder hook" {
+ -re "= .*_Unwind_DebugHook.*\r\n$gdb_prompt $" {
+ pass "check for unwinder hook"
+ }
+ -re "No symbol .* in current context.\r\n$gdb_prompt $" {
+ # Pass the test so we don't get bogus fails in the results.
+ pass "check for unwinder hook"
+ set ok 0
+ }
+}
+if {!$ok} {
+ untested gdb9593.exp
+ return -1
+}
+
+# See http://sourceware.org/bugzilla/show_bug.cgi?id=9593
+
+gdb_test "next" \
+ ".*catch (...).*" \
+ "next over a throw 1"
+
+gdb_test "next" \
+ ".*next_cases.function2.*" \
+ "next past catch 1"
+
+gdb_test "next" \
+ ".*catch (...).*" \
+ "next over a throw 2"
+
+gdb_test "next" \
+ ".*next_cases.function2.*" \
+ "next past catch 2"
+
+gdb_test "step" \
+ ".*function1().*" \
+ "step into function2 1"
+
+gdb_test "next" \
+ ".*catch (...).*" \
+ "next over a throw 3"
+
+gdb_test "next" \
+ ".*next_cases.function3.*" \
+ "next past catch 3"
+
+gdb_test "next" \
+ ".*next_cases.rethrow.*" \
+ "next over a throw 4"
+
+gdb_test "next" \
+ ".*catch (...).*" \
+ "next over a rethrow"
+
+gdb_test "next" \
+ ".*next_cases.function2.*" \
+ "next after a rethrow"
+
+gdb_test "step" \
+ ".*function1().*" \
+ "step into function2 2"
+
+gdb_test "finish" \
+ ".*catch (...).*" \
+ "finish 1"
+
+gdb_test "next" \
+ ".*next_cases.finish ().*" \
+ "next past catch 4"
+
+gdb_test "step" \
+ ".*function1 ().*" \
+ "step into finish method"
+
+gdb_test "finish" \
+ ".*catch (...).*" \
+ "finish 2"
+
+gdb_test "next" \
+ ".*next_cases.finish ().*" \
+ "next past catch 5"
+
+gdb_test "step" \
+ ".*function1 ().*" \
+ "step into finish, for until"
+
+gdb_test "until" \
+ ".*catch .int x.*" \
+ "until with no argument 1"
+
+set line [gdb_get_line_number "marker for until" $testfile.cc]
+
+gdb_test "until $line" \
+ ".*function1 ().*" \
+ "next past catch 6"
+
+gdb_test "until" \
+ ".*catch (...).*" \
+ "until with no argument 2"
+
+set line [gdb_get_line_number "until here" $testfile.cc]
+
+gdb_test "next" \
+ ".*next_cases.until ().*" \
+ "next past catch 6"
+
+gdb_test "step" \
+ ".*function1 ().*" \
+ "step into until"
+
+gdb_test "until $line" \
+ ".*catch (...).*" \
+ "until-over-throw"
+
+gdb_test "next" \
+ ".*next_cases.until ().*" \
+ "next past catch 7"
+
+gdb_test "step" \
+ ".*function1 ().*" \
+ "step into until, for advance"
+
+gdb_test "advance $line" \
+ ".*catch (...).*" \
+ "advance-over-throw"
diff --git a/gdb/testsuite/gdb.java/jnpe.exp b/gdb/testsuite/gdb.java/jnpe.exp
new file mode 100644
index 0000000..74d4d58
--- /dev/null
+++ b/gdb/testsuite/gdb.java/jnpe.exp
@@ -0,0 +1,72 @@
+# Copyright 2009 Free Software Foundation, Inc.
+
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program. If not, see <http://www.gnu.org/licenses/>.
+
+if $tracelevel then {
+ strace $tracelevel
+}
+
+load_lib "java.exp"
+
+set testfile "jnpe"
+set srcfile ${srcdir}/$subdir/${testfile}.java
+set binfile ${objdir}/${subdir}/${testfile}
+if { [compile_java_from_source ${srcfile} ${binfile} "-g"] != "" } {
+ untested "Couldn't compile ${srcfile}"
+ return -1
+}
+
+set prms_id 0
+set bug_id 0
+
+# Start with a fresh gdb.
+
+gdb_exit
+gdb_start
+gdb_reinitialize_dir $srcdir/$subdir
+gdb_load ${binfile}
+
+set line [gdb_get_line_number "break here" $testfile.java]
+gdb_test "break $testfile.java:$line" ""
+
+gdb_test "run" \
+ "Current language.*java" \
+ "run java next-over-throw"
+
+# See whether we have the needed unwinder hooks.
+set ok 1
+gdb_test_multiple "print _Unwind_DebugHook" "check for unwinder hook in java" {
+ -re "= .*_Unwind_DebugHook.*\r\n$gdb_prompt $" {
+ pass "check for unwinder hook in java"
+ }
+ -re "No symbol .* in current context.\r\n$gdb_prompt $" {
+ # Pass the test so we don't get bogus fails in the results.
+ pass "check for unwinder hook in java"
+ set ok 0
+ }
+}
+if {!$ok} {
+ untested jnpe.exp
+ return -1
+}
+
+gdb_test "handle SIGSEGV nostop noprint" \
+ "SIGSEGV.*fault" \
+ "disable SIGSEGV for next-over-NPE"
+
+# We sometimes stop at line 37, not line 35. This seems to be a gcj
+# oddity -- another next will solve it.
+gdb_test "next" \
+ "3\[57\].*" \
+ "next over NPE"
diff --git a/gdb/testsuite/gdb.java/jnpe.java b/gdb/testsuite/gdb.java/jnpe.java
new file mode 100644
index 0000000..ffca3ab
--- /dev/null
+++ b/gdb/testsuite/gdb.java/jnpe.java
@@ -0,0 +1,38 @@
+// Test next-over-NPE.
+/* This testcase is part of GDB, the GNU debugger.
+
+ Copyright 2009 Free Software Foundation, Inc.
+
+ This program is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation; either version 3 of the License, or
+ (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+public class jnpe
+{
+ public static String npe ()
+ {
+ return ((Object) null).toString();
+ }
+
+ public static void main (String[] args)
+ {
+ try
+ {
+ System.out.println (npe ()); // break here
+ }
+ catch (NullPointerException n)
+ {
+ System.out.println ("success");
+ }
+ }
+}