GDB 7.6.50

gdb/break-catch-throw.c

Index: gdb/break-catch-throw.c
diff --git a/gdb/break-catch-throw.c b/gdb/break-catch-throw.c
new file mode 100644
index 0000000000000000000000000000000000000000..76087d31606f25522c994eea42ecc8ea3a9720ac
--- /dev/null
+++ b/gdb/break-catch-throw.c
@@ -0,0 +1,592 @@
+/* Everything about catch/throw catchpoints, for GDB.
+
+   Copyright (C) 1986-2013 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"
+#include "mi/mi-common.h"
+#include "exceptions.h"
+#include "linespec.h"
+#include "probe.h"
+#include "objfiles.h"
+#include "cp-abi.h"
+#include "gdb_regex.h"
+#include "cp-support.h"
+
+/* Enums for exception-handling support.  */
+enum exception_event_kind
+{
+  EX_EVENT_THROW,
+  EX_EVENT_RETHROW,
+  EX_EVENT_CATCH
+};
+
+/* Each spot where we may place an exception-related catchpoint has
+   two names: the SDT probe point and the function name.  This
+   structure holds both.  */
+
+struct exception_names
+{
+  /* The name of the probe point to try, in the form accepted by
+     'parse_probes'.  */
+
+  const char *probe;
+
+  /* The name of the corresponding function.  */
+
+  const char *function;
+};
+
+/* Names of the probe points and functions on which to break.  This is
+   indexed by exception_event_kind.  */
+static const struct exception_names exception_functions[] =
+{
+  { "-probe-stap libstdcxx:throw", "__cxa_throw" },
+  { "-probe-stap libstdcxx:rethrow", "__cxa_rethrow" },
+  { "-probe-stap libstdcxx:catch", "__cxa_begin_catch" }
+};
+
+static struct breakpoint_ops gnu_v3_exception_catchpoint_ops;
+
+/* The type of an exception catchpoint.  */
+
+struct exception_catchpoint
+{
+  /* The base class.  */
+
+  struct breakpoint base;
+
+  /* The kind of exception catchpoint.  */
+
+  enum exception_event_kind kind;
+
+  /* If non-NULL, an xmalloc'd string holding the source form of the
+     regular expression to match against.  */
+
+  char *exception_rx;
+
+  /* If non-NULL, an xmalloc'd, compiled regular expression which is
+     used to determine which exceptions to stop on.  */
+
+  regex_t *pattern;
+};
+
+
+
+/* A helper function that fetches exception probe arguments.  This
+   fills in *ARG0 (if non-NULL) and *ARG1 (which must be non-NULL).
+   It will throw an exception on any kind of failure.  */
+
+static void
+fetch_probe_arguments (struct value **arg0, struct value **arg1)
+{
+  struct frame_info *frame = get_selected_frame (_("No frame selected"));
+  CORE_ADDR pc = get_frame_pc (frame);
+  struct probe *pc_probe;
+  const struct sym_probe_fns *pc_probe_fns;
+  unsigned n_args;
+
+  pc_probe = find_probe_by_pc (pc);
+  if (pc_probe == NULL
+      || strcmp (pc_probe->provider, "libstdcxx") != 0
+      || (strcmp (pc_probe->name, "catch") != 0
+	  && strcmp (pc_probe->name, "throw") != 0
+	  && strcmp (pc_probe->name, "rethrow") != 0))
+    error (_("not stopped at a C++ exception catchpoint"));
+
+  n_args = get_probe_argument_count (pc_probe);
+  if (n_args < 2)
+    error (_("C++ exception catchpoint has too few arguments"));
+
+  if (arg0 != NULL)
+    *arg0 = evaluate_probe_argument (pc_probe, 0);
+  *arg1 = evaluate_probe_argument (pc_probe, 1);
+
+  if ((arg0 != NULL && *arg0 == NULL) || *arg1 == NULL)
+    error (_("error computing probe argument at c++ exception catchpoint"));
+}
+
+
+
+/* A helper function that returns a value indicating the kind of the
+   exception catchpoint B.  */
+
+static enum exception_event_kind
+classify_exception_breakpoint (struct breakpoint *b)
+{
+  struct exception_catchpoint *cp = (struct exception_catchpoint *) b;
+
+  return cp->kind;
+}
+
+/* Implement the 'dtor' method.  */
+
+static void
+dtor_exception_catchpoint (struct breakpoint *self)
+{
+  struct exception_catchpoint *cp = (struct exception_catchpoint *) self;
+
+  xfree (cp->exception_rx);
+  if (cp->pattern != NULL)
+    regfree (cp->pattern);
+  bkpt_breakpoint_ops.dtor (self);
+}
+
+/* Implement the 'check_status' method.  */
+
+static void
+check_status_exception_catchpoint (struct bpstats *bs)
+{
+  struct exception_catchpoint *self
+    = (struct exception_catchpoint *) bs->breakpoint_at;
+  char *typename = NULL;
+  volatile struct gdb_exception e;
+
+  bkpt_breakpoint_ops.check_status (bs);
+  if (bs->stop == 0)
+    return;
+
+  if (self->pattern == NULL)
+    return;
+
+  TRY_CATCH (e, RETURN_MASK_ERROR)
+    {
+      struct value *typeinfo_arg;
+      char *canon;
+
+      fetch_probe_arguments (NULL, &typeinfo_arg);
+      typename = cplus_typename_from_type_info (typeinfo_arg);
+
+      canon = cp_canonicalize_string (typename);
+      if (canon != NULL)
+	{
+	  xfree (typename);
+	  typename = canon;
+	}
+    }
+
+  if (e.reason < 0)
+    exception_print (gdb_stderr, e);
+  else if (regexec (self->pattern, typename, 0, NULL, 0) != 0)
+    bs->stop = 0;
+
+  xfree (typename);
+}
+
+/* Implement the 're_set' method.  */
+
+static void
+re_set_exception_catchpoint (struct breakpoint *self)
+{
+  struct symtabs_and_lines sals = {0};
+  struct symtabs_and_lines sals_end = {0};
+  volatile struct gdb_exception e;
+  struct cleanup *cleanup;
+  enum exception_event_kind kind = classify_exception_breakpoint (self);
+  int pass;
+
+  for (pass = 0; sals.sals == NULL && pass < 2; ++pass)
+    {
+      TRY_CATCH (e, RETURN_MASK_ERROR)
+	{
+	  char *spec;
+
+	  if (pass == 0)
+	    {
+	      spec = ASTRDUP (exception_functions[kind].probe);
+	      sals = parse_probes (&spec, NULL);
+	    }
+	  else
+	    {
+	      spec = ASTRDUP (exception_functions[kind].function);
+	      self->ops->decode_linespec (self, &spec, &sals);
+	    }
+	}
+      /* NOT_FOUND_ERROR just means the breakpoint will be pending, so
+	 let it through.  */
+      if (e.reason < 0 && e.error != NOT_FOUND_ERROR)
+	throw_exception (e);
+    }
+
+  cleanup = make_cleanup (xfree, sals.sals);
+  update_breakpoint_locations (self, sals, sals_end);
+  do_cleanups (cleanup);
+}
+
+static enum print_stop_action
+print_it_exception_catchpoint (bpstat bs)
+{
+  struct ui_out *uiout = current_uiout;
+  struct breakpoint *b = bs->breakpoint_at;
+  int bp_temp;
+  enum exception_event_kind kind = classify_exception_breakpoint (b);
+
+  annotate_catchpoint (b->number);
+
+  bp_temp = b->disposition == disp_del;
+  ui_out_text (uiout, 
+	       bp_temp ? "Temporary catchpoint "
+		       : "Catchpoint ");
+  if (!ui_out_is_mi_like_p (uiout))
+    ui_out_field_int (uiout, "bkptno", b->number);
+  ui_out_text (uiout,
+	       (kind == EX_EVENT_THROW ? " (exception thrown), "
+		: (kind == EX_EVENT_CATCH ? " (exception caught), "
+		   : " (exception rethrown), ")));
+  if (ui_out_is_mi_like_p (uiout))
+    {
+      ui_out_field_string (uiout, "reason", 
+			   async_reason_lookup (EXEC_ASYNC_BREAKPOINT_HIT));
+      ui_out_field_string (uiout, "disp", bpdisp_text (b->disposition));
+      ui_out_field_int (uiout, "bkptno", b->number);
+    }
+  return PRINT_SRC_AND_LOC;
+}
+
+static void
+print_one_exception_catchpoint (struct breakpoint *b, 
+				struct bp_location **last_loc)
+{
+  struct value_print_options opts;
+  struct ui_out *uiout = current_uiout;
+  enum exception_event_kind kind = classify_exception_breakpoint (b);
+
+  get_user_print_options (&opts);
+  if (opts.addressprint)
+    {
+      annotate_field (4);
+      if (b->loc == NULL || b->loc->shlib_disabled)
+	ui_out_field_string (uiout, "addr", "<PENDING>");
+      else
+	ui_out_field_core_addr (uiout, "addr",
+				b->loc->gdbarch, b->loc->address);
+    }
+  annotate_field (5);
+  if (b->loc)
+    *last_loc = b->loc;
+
+  switch (kind)
+    {
+    case EX_EVENT_THROW:
+      ui_out_field_string (uiout, "what", "exception throw");
+      if (ui_out_is_mi_like_p (uiout))
+	ui_out_field_string (uiout, "catch-type", "throw");
+      break;
+
+    case EX_EVENT_RETHROW:
+      ui_out_field_string (uiout, "what", "exception rethrow");
+      if (ui_out_is_mi_like_p (uiout))
+	ui_out_field_string (uiout, "catch-type", "rethrow");
+      break;
+
+    case EX_EVENT_CATCH:
+      ui_out_field_string (uiout, "what", "exception catch");
+      if (ui_out_is_mi_like_p (uiout))
+	ui_out_field_string (uiout, "catch-type", "catch");
+      break;
+    }
+}
+
+/* Implement the 'print_one_detail' method.  */
+
+static void
+print_one_detail_exception_catchpoint (const struct breakpoint *b,
+				       struct ui_out *uiout)
+{
+  const struct exception_catchpoint *cp
+    = (const struct exception_catchpoint *) b;
+
+  if (cp->exception_rx != NULL)
+    {
+      ui_out_text (uiout, _("\tmatching: "));
+      ui_out_field_string (uiout, "regexp", cp->exception_rx);
+      ui_out_text (uiout, "\n");
+    }
+}
+
+static void
+print_mention_exception_catchpoint (struct breakpoint *b)
+{
+  struct ui_out *uiout = current_uiout;
+  int bp_temp;
+  enum exception_event_kind kind = classify_exception_breakpoint (b);
+
+  bp_temp = b->disposition == disp_del;
+  ui_out_text (uiout, bp_temp ? _("Temporary catchpoint ")
+			      : _("Catchpoint "));
+  ui_out_field_int (uiout, "bkptno", b->number);
+  ui_out_text (uiout, (kind == EX_EVENT_THROW ? _(" (throw)")
+		       : (kind == EX_EVENT_CATCH ? _(" (catch)")
+			  : _(" (rethrow)"))));
+}
+
+/* Implement the "print_recreate" breakpoint_ops method for throw and
+   catch catchpoints.  */
+
+static void
+print_recreate_exception_catchpoint (struct breakpoint *b, 
+				     struct ui_file *fp)
+{
+  int bp_temp;
+  enum exception_event_kind kind = classify_exception_breakpoint (b);
+
+  bp_temp = b->disposition == disp_del;
+  fprintf_unfiltered (fp, bp_temp ? "tcatch " : "catch ");
+  switch (kind)
+    {
+    case EX_EVENT_THROW:
+      fprintf_unfiltered (fp, "throw");
+      break;
+    case EX_EVENT_CATCH:
+      fprintf_unfiltered (fp, "catch");
+      break;
+    case EX_EVENT_RETHROW:
+      fprintf_unfiltered (fp, "rethrow");
+      break;
+    }
+  print_recreate_thread (b, fp);
+}
+
+static void
+handle_gnu_v3_exceptions (int tempflag, char *except_rx, char *cond_string,
+			  enum exception_event_kind ex_event, int from_tty)
+{
+  struct exception_catchpoint *cp;
+  struct cleanup *cleanup = make_cleanup (null_cleanup, NULL);
+  regex_t *pattern = NULL;
+
+  if (except_rx != NULL)
+    {
+      pattern = XNEW (regex_t);
+      make_cleanup (xfree, pattern);
+
+      compile_rx_or_error (pattern, except_rx,
+			   _("invalid type-matching regexp"));
+    }
+
+  cp = XCNEW (struct exception_catchpoint);
+  make_cleanup (xfree, cp);
+
+  init_catchpoint (&cp->base, get_current_arch (), tempflag, cond_string,
+		   &gnu_v3_exception_catchpoint_ops);
+  /* We need to reset 'type' in order for code in breakpoint.c to do
+     the right thing.  */
+  cp->base.type = bp_breakpoint;
+  cp->kind = ex_event;
+  cp->exception_rx = except_rx;
+  cp->pattern = pattern;
+
+  re_set_exception_catchpoint (&cp->base);
+
+  install_breakpoint (0, &cp->base, 1);
+  discard_cleanups (cleanup);
+}
+
+/* Look for an "if" token in *STRING.  The "if" token must be preceded
+   by whitespace.
+   
+   If there is any non-whitespace text between *STRING and the "if"
+   token, then it is returned in a newly-xmalloc'd string.  Otherwise,
+   this returns NULL.
+   
+   STRING is updated to point to the "if" token, if it exists, or to
+   the end of the string.  */
+
+static char *
+extract_exception_regexp (char **string)
+{
+  char *start;
+  char *last, *last_space;
+
+  start = skip_spaces (*string);
+
+  last = start;
+  last_space = start;
+  while (*last != '\0')
+    {
+      char *if_token = last;
+
+      /* Check for the "if".  */
+      if (check_for_argument (&if_token, "if", 2))
+	break;
+
+      /* No "if" token here.  Skip to the next word start.  */
+      last_space = skip_to_space (last);
+      last = skip_spaces (last_space);
+    }
+
+  *string = last;
+  if (last_space > start)
+    return savestring (start, last_space - start);
+  return NULL;
+}
+
+/* Deal with "catch catch", "catch throw", and "catch rethrow"
+   commands.  */
+
+static void
+catch_exception_command_1 (enum exception_event_kind ex_event, char *arg,
+			   int tempflag, int from_tty)
+{
+  char *except_rx;
+  char *cond_string = NULL;
+  struct cleanup *cleanup;
+
+  if (!arg)
+    arg = "";
+  arg = skip_spaces (arg);
+
+  except_rx = extract_exception_regexp (&arg);
+  cleanup = make_cleanup (xfree, except_rx);
+
+  cond_string = ep_parse_optional_if_clause (&arg);
+
+  if ((*arg != '\0') && !isspace (*arg))
+    error (_("Junk at end of arguments."));
+
+  if (ex_event != EX_EVENT_THROW
+      && ex_event != EX_EVENT_CATCH
+      && ex_event != EX_EVENT_RETHROW)
+    error (_("Unsupported or unknown exception event; cannot catch it"));
+
+  handle_gnu_v3_exceptions (tempflag, except_rx, cond_string,
+			    ex_event, from_tty);
+
+  discard_cleanups (cleanup);
+}
+
+/* Implementation of "catch catch" command.  */
+
+static void
+catch_catch_command (char *arg, int from_tty, struct cmd_list_element *command)
+{
+  int tempflag = get_cmd_context (command) == CATCH_TEMPORARY;
+
+  catch_exception_command_1 (EX_EVENT_CATCH, arg, tempflag, from_tty);
+}
+
+/* Implementation of "catch throw" command.  */
+
+static void
+catch_throw_command (char *arg, int from_tty, struct cmd_list_element *command)
+{
+  int tempflag = get_cmd_context (command) == CATCH_TEMPORARY;
+
+  catch_exception_command_1 (EX_EVENT_THROW, arg, tempflag, from_tty);
+}
+
+/* Implementation of "catch rethrow" command.  */
+
+static void
+catch_rethrow_command (char *arg, int from_tty,
+		       struct cmd_list_element *command)
+{
+  int tempflag = get_cmd_context (command) == CATCH_TEMPORARY;
+
+  catch_exception_command_1 (EX_EVENT_RETHROW, arg, tempflag, from_tty);
+}
+
+
+
+/* Implement the 'make_value' method for the $_exception
+   internalvar.  */
+
+static struct value *
+compute_exception (struct gdbarch *argc, struct internalvar *var, void *ignore)
+{
+  struct value *arg0, *arg1;
+  struct type *obj_type;
+
+  fetch_probe_arguments (&arg0, &arg1);
+
+  /* ARG0 is a pointer to the exception object.  ARG1 is a pointer to
+     the std::type_info for the exception.  Now we find the type from
+     the type_info and cast the result.  */
+  obj_type = cplus_type_from_type_info (arg1);
+  return value_ind (value_cast (make_pointer_type (obj_type, NULL), arg0));
+}
+
+/* Implementation of the '$_exception' variable.  */
+
+static const struct internalvar_funcs exception_funcs =
+{
+  compute_exception,
+  NULL,
+  NULL
+};
+
+
+
+static void
+initialize_throw_catchpoint_ops (void)
+{
+  struct breakpoint_ops *ops;
+
+  initialize_breakpoint_ops ();
+
+  /* GNU v3 exception catchpoints.  */
+  ops = &gnu_v3_exception_catchpoint_ops;
+  *ops = bkpt_breakpoint_ops;
+  ops->dtor = dtor_exception_catchpoint;
+  ops->re_set = re_set_exception_catchpoint;
+  ops->print_it = print_it_exception_catchpoint;
+  ops->print_one = print_one_exception_catchpoint;
+  ops->print_mention = print_mention_exception_catchpoint;
+  ops->print_recreate = print_recreate_exception_catchpoint;
+  ops->print_one_detail = print_one_detail_exception_catchpoint;
+  ops->check_status = check_status_exception_catchpoint;
+}
+
+initialize_file_ftype _initialize_break_catch_throw;
+
+void
+_initialize_break_catch_throw (void)
+{
+  initialize_throw_catchpoint_ops ();
+
+  /* Add catch and tcatch sub-commands.  */
+  add_catch_command ("catch", _("\
+Catch an exception, when caught."),
+		     catch_catch_command,
+                     NULL,
+		     CATCH_PERMANENT,
+		     CATCH_TEMPORARY);
+  add_catch_command ("throw", _("\
+Catch an exception, when thrown."),
+		     catch_throw_command,
+                     NULL,
+		     CATCH_PERMANENT,
+		     CATCH_TEMPORARY);
+  add_catch_command ("rethrow", _("\
+Catch an exception, when rethrown."),
+		     catch_rethrow_command,
+                     NULL,
+		     CATCH_PERMANENT,
+		     CATCH_TEMPORARY);
+
+  create_internalvar_type_lazy ("_exception", &exception_funcs, NULL);
+}