2013-01-03 Pedro Alves <palves@redhat.com>

	    Tom Tromey  <tromey@redhat.com>
	PR cli/7221:
	* NEWS: Add "catch signal".
	* breakpoint.c (base_breakpoint_ops): No longer static.
	(bpstat_explains_signal): New function.
	(init_catchpoint): No longer static.
	(base_breakpoint_explains_signal): New function.
	(base_breakpoint_ops): Initialize new field.
	* breakpoint.h (enum bpstat_signal_value): New.
	(struct breakpoint_ops) <explains_signal>: New field.
	(bpstat_explains_signal): Remove macro, declare as function.
	(base_breakpoint_ops, init_catchpoint): Declare.
	* break-catch-sig.c: New file.
	* inferior.h (signal_catch_update): Declare.
	* infrun.c (signal_catch): New global.
	(handle_syscall_event): Update for change to
	bpstat_explains_signal.
	(handle_inferior_event): Likewise.  Always handle random signals
	via bpstats.
	(signal_cache_update): Check signal_catch.
	(signal_catch_update): New function.
	(_initialize_infrun): Initialize signal_catch.
	* Makefile.in (SFILES): Add break-catch-sig.c.
	(COMMON_OBS): Add break-catch-sig.o.
gdb/doc
	* gdb.texinfo (Set Catchpoints): Document "catch signal".
	(Signals): Likewise.
gdb/testsuite
	* gdb.base/catch-signal.c: New file.
	* gdb.base/catch-signal.exp: New file.

1 files changed, 508 insertions, 0 deletions

diff --git a/gdb/break-catch-sig.c b/gdb/break-catch-sig.c
new file mode 100644
index 0000000..89783b0
--- /dev/null
+++ b/gdb/break-catch-sig.c
@@ -0,0 +1,508 @@
+/* Everything about signal catchpoints, for GDB.
+
+   Copyright (C) 2011, 2012 Free Software Foundation, Inc.
+
+   This file is part of GDB.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
+
+#include "defs.h"
+#include "arch-utils.h"
+#include <ctype.h>
+#include "breakpoint.h"
+#include "gdbcmd.h"
+#include "inferior.h"
+#include "annotate.h"
+#include "valprint.h"
+#include "cli/cli-utils.h"
+#include "completer.h"
+#include "gdb_obstack.h"
+
+#define INTERNAL_SIGNAL(x) ((x) == GDB_SIGNAL_TRAP || (x) == GDB_SIGNAL_INT)
+
+typedef enum gdb_signal gdb_signal_type;
+
+DEF_VEC_I (gdb_signal_type);
+
+/* An instance of this type is used to represent a signal catchpoint.
+   It includes a "struct breakpoint" as a kind of base class; users
+   downcast to "struct breakpoint *" when needed.  A breakpoint is
+   really of this type iff its ops pointer points to
+   SIGNAL_CATCHPOINT_OPS.  */
+
+struct signal_catchpoint
+{
+  /* The base class.  */
+
+  struct breakpoint base;
+
+  /* Signal numbers used for the 'catch signal' feature.  If no signal
+     has been specified for filtering, its value is NULL.  Otherwise,
+     it holds a list of all signals to be caught.  */
+
+  VEC (gdb_signal_type) *signals_to_be_caught;
+
+  /* If SIGNALS_TO_BE_CAUGHT is NULL, then all "ordinary" signals are
+     caught.  If CATCH_ALL is non-zero, then internal signals are
+     caught as well.  If SIGNALS_TO_BE_CAUGHT is non-NULL, then this
+     field is ignored.  */
+
+  int catch_all;
+};
+
+/* The breakpoint_ops structure to be used in signal catchpoints.  */
+
+static struct breakpoint_ops signal_catchpoint_ops;
+
+/* Count of each signal.  */
+
+static unsigned int *signal_catch_counts;
+
+
+
+/* A convenience wrapper for gdb_signal_to_name that returns the
+   integer value if the name is not known.  */
+
+static const char *
+signal_to_name_or_int (enum gdb_signal sig)
+{
+  const char *result = gdb_signal_to_name (sig);
+
+  if (strcmp (result, "?") == 0)
+    result = plongest (sig);
+
+  return result;
+}
+
+
+
+/* Implement the "dtor" breakpoint_ops method for signal
+   catchpoints.  */
+
+static void
+signal_catchpoint_dtor (struct breakpoint *b)
+{
+  struct signal_catchpoint *c = (struct signal_catchpoint *) b;
+
+  VEC_free (gdb_signal_type, c->signals_to_be_caught);
+
+  base_breakpoint_ops.dtor (b);
+}
+
+/* Implement the "insert_location" breakpoint_ops method for signal
+   catchpoints.  */
+
+static int
+signal_catchpoint_insert_location (struct bp_location *bl)
+{
+  struct signal_catchpoint *c = (void *) bl->owner;
+  int i;
+
+  if (c->signals_to_be_caught != NULL)
+    {
+      gdb_signal_type iter;
+
+      for (i = 0;
+	   VEC_iterate (gdb_signal_type, c->signals_to_be_caught, i, iter);
+	   i++)
+	++signal_catch_counts[iter];
+    }
+  else
+    {
+      for (i = 0; i < GDB_SIGNAL_LAST; ++i)
+	{
+	  if (c->catch_all || !INTERNAL_SIGNAL (i))
+	    ++signal_catch_counts[i];
+	}
+    }
+
+  signal_catch_update (signal_catch_counts);
+
+  return 0;
+}
+
+/* Implement the "remove_location" breakpoint_ops method for signal
+   catchpoints.  */
+
+static int
+signal_catchpoint_remove_location (struct bp_location *bl)
+{
+  struct signal_catchpoint *c = (void *) bl->owner;
+  int i;
+
+  if (c->signals_to_be_caught != NULL)
+    {
+      gdb_signal_type iter;
+
+      for (i = 0;
+	   VEC_iterate (gdb_signal_type, c->signals_to_be_caught, i, iter);
+	   i++)
+	{
+	  gdb_assert (signal_catch_counts[iter] > 0);
+	  --signal_catch_counts[iter];
+	}
+    }
+  else
+    {
+      for (i = 0; i < GDB_SIGNAL_LAST; ++i)
+	{
+	  if (c->catch_all || !INTERNAL_SIGNAL (i))
+	    {
+	      gdb_assert (signal_catch_counts[i] > 0);
+	      --signal_catch_counts[i];
+	    }
+	}
+    }
+
+  signal_catch_update (signal_catch_counts);
+
+  return 0;
+}
+
+/* Implement the "breakpoint_hit" breakpoint_ops method for signal
+   catchpoints.  */
+
+static int
+signal_catchpoint_breakpoint_hit (const struct bp_location *bl,
+				  struct address_space *aspace,
+				  CORE_ADDR bp_addr,
+				  const struct target_waitstatus *ws)
+{
+  const struct signal_catchpoint *c = (void *) bl->owner;
+  gdb_signal_type signal_number;
+
+  if (ws->kind != TARGET_WAITKIND_STOPPED)
+    return 0;
+
+  signal_number = ws->value.sig;
+
+  /* If we are catching specific signals in this breakpoint, then we
+     must guarantee that the called signal is the same signal we are
+     catching.  */
+  if (c->signals_to_be_caught)
+    {
+      int i;
+      gdb_signal_type iter;
+
+      for (i = 0;
+           VEC_iterate (gdb_signal_type, c->signals_to_be_caught, i, iter);
+           i++)
+	if (signal_number == iter)
+	  break;
+      /* Not the same.  */
+      if (!iter)
+	return 0;
+    }
+
+  return c->catch_all || !INTERNAL_SIGNAL (signal_number);
+}
+
+/* Implement the "print_it" breakpoint_ops method for signal
+   catchpoints.  */
+
+static enum print_stop_action
+signal_catchpoint_print_it (bpstat bs)
+{
+  struct breakpoint *b = bs->breakpoint_at;
+  ptid_t ptid;
+  struct target_waitstatus last;
+  const char *signal_name;
+
+  get_last_target_status (&ptid, &last);
+
+  signal_name = signal_to_name_or_int (last.value.sig);
+
+  annotate_catchpoint (b->number);
+
+  printf_filtered (_("\nCatchpoint %d (signal %s), "), b->number, signal_name);
+
+  return PRINT_SRC_AND_LOC;
+}
+
+/* Implement the "print_one" breakpoint_ops method for signal
+   catchpoints.  */
+
+static void
+signal_catchpoint_print_one (struct breakpoint *b,
+			     struct bp_location **last_loc)
+{
+  struct signal_catchpoint *c = (void *) b;
+  struct value_print_options opts;
+  struct ui_out *uiout = current_uiout;
+
+  get_user_print_options (&opts);
+
+  /* Field 4, the address, is omitted (which makes the columns
+     not line up too nicely with the headers, but the effect
+     is relatively readable).  */
+  if (opts.addressprint)
+    ui_out_field_skip (uiout, "addr");
+  annotate_field (5);
+
+  if (c->signals_to_be_caught
+      && VEC_length (gdb_signal_type, c->signals_to_be_caught) > 1)
+    ui_out_text (uiout, "signals \"");
+  else
+    ui_out_text (uiout, "signal \"");
+
+  if (c->signals_to_be_caught)
+    {
+      int i;
+      gdb_signal_type iter;
+      struct obstack text;
+      struct cleanup *cleanup;
+
+      obstack_init (&text);
+      cleanup = make_cleanup_obstack_free (&text);
+
+      for (i = 0;
+           VEC_iterate (gdb_signal_type, c->signals_to_be_caught, i, iter);
+           i++)
+        {
+	  const char *name = signal_to_name_or_int (iter);
+
+	  if (i > 0)
+	    obstack_grow (&text, " ", 1);
+	  obstack_grow (&text, name, strlen (name));
+        }
+      obstack_grow (&text, "", 1);
+      ui_out_field_string (uiout, "what", obstack_base (&text));
+      do_cleanups (cleanup);
+    }
+  else
+    ui_out_field_string (uiout, "what",
+			 c->catch_all ? "<any signal>" : "<standard signals>");
+  ui_out_text (uiout, "\" ");
+
+  if (ui_out_is_mi_like_p (uiout))
+    ui_out_field_string (uiout, "catch-type", "signal");
+}
+
+/* Implement the "print_mention" breakpoint_ops method for signal
+   catchpoints.  */
+
+static void
+signal_catchpoint_print_mention (struct breakpoint *b)
+{
+  struct signal_catchpoint *c = (void *) b;
+
+  if (c->signals_to_be_caught)
+    {
+      int i;
+      gdb_signal_type iter;
+
+      if (VEC_length (gdb_signal_type, c->signals_to_be_caught) > 1)
+        printf_filtered (_("Catchpoint %d (signals"), b->number);
+      else
+        printf_filtered (_("Catchpoint %d (signal"), b->number);
+
+      for (i = 0;
+           VEC_iterate (gdb_signal_type, c->signals_to_be_caught, i, iter);
+           i++)
+        {
+	  const char *name = signal_to_name_or_int (iter);
+
+	  printf_filtered (" %s", name);
+        }
+      printf_filtered (")");
+    }
+  else if (c->catch_all)
+    printf_filtered (_("Catchpoint %d (any signal)"), b->number);
+  else
+    printf_filtered (_("Catchpoint %d (standard signals)"), b->number);
+}
+
+/* Implement the "print_recreate" breakpoint_ops method for signal
+   catchpoints.  */
+
+static void
+signal_catchpoint_print_recreate (struct breakpoint *b, struct ui_file *fp)
+{
+  struct signal_catchpoint *c = (void *) b;
+
+  fprintf_unfiltered (fp, "catch signal");
+
+  if (c->signals_to_be_caught)
+    {
+      int i;
+      gdb_signal_type iter;
+
+      for (i = 0;
+           VEC_iterate (gdb_signal_type, c->signals_to_be_caught, i, iter);
+           i++)
+	fprintf_unfiltered (fp, " %s", signal_to_name_or_int (iter));
+    }
+  else if (c->catch_all)
+    fprintf_unfiltered (fp, " all");
+}
+
+/* Implement the "explains_signal" breakpoint_ops method for signal
+   catchpoints.  */
+
+static enum bpstat_signal_value
+signal_catchpoint_explains_signal (struct breakpoint *b)
+{
+  return BPSTAT_SIGNAL_PASS;
+}
+
+/* Create a new signal catchpoint.  TEMPFLAG is true if this should be
+   a temporary catchpoint.  FILTER is the list of signals to catch; it
+   can be NULL, meaning all signals.  CATCH_ALL is a flag indicating
+   whether signals used internally by gdb should be caught; it is only
+   valid if FILTER is NULL.  If FILTER is NULL and CATCH_ALL is zero,
+   then internal signals like SIGTRAP are not caught.  */
+
+static void
+create_signal_catchpoint (int tempflag, VEC (gdb_signal_type) *filter,
+			  int catch_all)
+{
+  struct signal_catchpoint *c;
+  struct gdbarch *gdbarch = get_current_arch ();
+
+  c = XNEW (struct signal_catchpoint);
+  init_catchpoint (&c->base, gdbarch, tempflag, NULL, &signal_catchpoint_ops);
+  c->signals_to_be_caught = filter;
+  c->catch_all = catch_all;
+
+  install_breakpoint (0, &c->base, 1);
+}
+
+
+/* Splits the argument using space as delimiter.  Returns an xmalloc'd
+   filter list, or NULL if no filtering is required.  */
+
+static VEC (gdb_signal_type) *
+catch_signal_split_args (char *arg, int *catch_all)
+{
+  VEC (gdb_signal_type) *result = NULL;
+  struct cleanup *cleanup = make_cleanup (VEC_cleanup (gdb_signal_type),
+					  &result);
+  int first = 1;
+
+  while (*arg != '\0')
+    {
+      int num;
+      gdb_signal_type signal_number;
+      char *one_arg, *endptr;
+      struct cleanup *inner_cleanup;
+
+      one_arg = extract_arg (&arg);
+      if (one_arg == NULL)
+	break;
+      inner_cleanup = make_cleanup (xfree, one_arg);
+
+      /* Check for the special flag "all".  */
+      if (strcmp (one_arg, "all") == 0)
+	{
+	  arg = skip_spaces (arg);
+	  if (*arg != '\0' || !first)
+	    error (_("'all' cannot be caught with other signals"));
+	  *catch_all = 1;
+	  gdb_assert (result == NULL);
+	  do_cleanups (inner_cleanup);
+	  discard_cleanups (cleanup);
+	  return NULL;
+	}
+
+      first = 0;
+
+      /* Check if the user provided a signal name or a number.  */
+      num = (int) strtol (one_arg, &endptr, 0);
+      if (*endptr == '\0')
+	signal_number = gdb_signal_from_command (num);
+      else
+	{
+	  signal_number = gdb_signal_from_name (one_arg);
+	  if (signal_number == GDB_SIGNAL_UNKNOWN)
+	    error (_("Unknown signal name '%s'."), one_arg);
+	}
+
+      VEC_safe_push (gdb_signal_type, result, signal_number);
+      do_cleanups (inner_cleanup);
+    }
+
+  discard_cleanups (cleanup);
+  return result;
+}
+
+/* Implement the "catch signal" command.  */
+
+static void
+catch_signal_command (char *arg, int from_tty,
+		      struct cmd_list_element *command)
+{
+  int tempflag, catch_all = 0;
+  VEC (gdb_signal_type) *filter;
+  struct gdbarch *gdbarch = get_current_arch ();
+
+  tempflag = get_cmd_context (command) == CATCH_TEMPORARY;
+
+  arg = skip_spaces (arg);
+
+  /* The allowed syntax is:
+     catch signal
+     catch signal <name | number> [<name | number> ... <name | number>]
+
+     Let's check if there's a signal name.  */
+
+  if (arg != NULL)
+    filter = catch_signal_split_args (arg, &catch_all);
+  else
+    filter = NULL;
+
+  create_signal_catchpoint (tempflag, filter, catch_all);
+}
+
+static void
+initialize_signal_catchpoint_ops (void)
+{
+  struct breakpoint_ops *ops;
+
+  initialize_breakpoint_ops ();
+
+  ops = &signal_catchpoint_ops;
+  *ops = base_breakpoint_ops;
+  ops->dtor = signal_catchpoint_dtor;
+  ops->insert_location = signal_catchpoint_insert_location;
+  ops->remove_location = signal_catchpoint_remove_location;
+  ops->breakpoint_hit = signal_catchpoint_breakpoint_hit;
+  ops->print_it = signal_catchpoint_print_it;
+  ops->print_one = signal_catchpoint_print_one;
+  ops->print_mention = signal_catchpoint_print_mention;
+  ops->print_recreate = signal_catchpoint_print_recreate;
+  ops->explains_signal = signal_catchpoint_explains_signal;
+}
+
+initialize_file_ftype _initialize_break_catch_sig;
+
+void
+_initialize_break_catch_sig (void)
+{
+  initialize_signal_catchpoint_ops ();
+
+  signal_catch_counts = XCNEWVEC (unsigned int, GDB_SIGNAL_LAST);
+
+  add_catch_command ("signal", _("\
+Catch signals by their names and/or numbers.\n\
+Usage: catch signal [[NAME|NUMBER] [NAME|NUMBER]...|all]\n\
+Arguments say which signals to catch.  If no arguments\n\
+are given, every \"normal\" signal will be caught.\n\
+The argument \"all\" means to also catch signals used by GDB.\n\
+Arguments, if given, should be one or more signal names\n\
+(if your system supports that), or signal numbers."),
+		     catch_signal_command,
+		     signal_completer,
+		     CATCH_PERMANENT,
+		     CATCH_TEMPORARY);
+}