/* Everything about catch/throw catchpoints, for GDB.
- Copyright (C) 1986-2013 Free Software Foundation, Inc.
+ Copyright (C) 1986-2014 Free Software Foundation, Inc.
This file is part of GDB.
#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_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;
+};
+
+\f
+
+/* 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 bound_probe pc_probe;
+ const struct sym_probe_fns *pc_probe_fns;
+ unsigned n_args;
+
+ pc_probe = find_probe_by_pc (pc);
+ if (pc_probe.probe == NULL
+ || strcmp (pc_probe.probe->provider, "libstdcxx") != 0
+ || (strcmp (pc_probe.probe->name, "catch") != 0
+ && strcmp (pc_probe.probe->name, "throw") != 0
+ && strcmp (pc_probe.probe->name, "rethrow") != 0))
+ error (_("not stopped at a C++ exception catchpoint"));
+
+ n_args = get_probe_argument_count (pc_probe.probe, frame);
+ if (n_args < 2)
+ error (_("C++ exception catchpoint has too few arguments"));
+
+ if (arg0 != NULL)
+ *arg0 = evaluate_probe_argument (pc_probe.probe, 0, frame);
+ *arg1 = evaluate_probe_argument (pc_probe.probe, 1, frame);
+
+ if ((arg0 != NULL && *arg0 == NULL) || *arg1 == NULL)
+ error (_("error computing probe argument at c++ exception catchpoint"));
+}
+
+\f
+
/* 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)
{
- if (strstr (b->addr_string, "catch") != NULL)
- return EX_EVENT_CATCH;
- else if (strstr (b->addr_string, "rethrow") != NULL)
- return EX_EVENT_RETHROW;
- else
- return EX_EVENT_THROW;
+ 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);
+
+ /* We first try to use the probe interface. */
+ TRY_CATCH (e, RETURN_MASK_ERROR)
+ {
+ char *spec = ASTRDUP (exception_functions[kind].probe);
+
+ sals = parse_probes (&spec, NULL);
+ }
+
+ if (e.reason < 0)
+ {
+ volatile struct gdb_exception ex;
+
+ /* Using the probe interface failed. Let's fallback to the normal
+ catchpoint mode. */
+ TRY_CATCH (ex, RETURN_MASK_ERROR)
+ {
+ char *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 (ex.reason < 0 && ex.error != NOT_FOUND_ERROR)
+ throw_exception (ex);
+ }
+
+ cleanup = make_cleanup (xfree, sals.sals);
+ update_breakpoint_locations (self, sals, sals_end);
+ do_cleanups (cleanup);
}
static enum print_stop_action
}
}
+/* 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)
{
print_recreate_thread (b, fp);
}
-static struct breakpoint_ops gnu_v3_exception_catchpoint_ops;
-
-static int
-handle_gnu_v3_exceptions (int tempflag, char *cond_string,
+static void
+handle_gnu_v3_exceptions (int tempflag, char *except_rx, char *cond_string,
enum exception_event_kind ex_event, int from_tty)
{
- char *trigger_func_name;
-
- if (ex_event == EX_EVENT_CATCH)
- trigger_func_name = "__cxa_begin_catch";
- else if (ex_event == EX_EVENT_RETHROW)
- trigger_func_name = "__cxa_rethrow";
- else
+ 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')
{
- gdb_assert (ex_event == EX_EVENT_THROW);
- trigger_func_name = "__cxa_throw";
+ 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);
}
- create_breakpoint (get_current_arch (),
- trigger_func_name, cond_string, -1, NULL,
- 0 /* condition and thread are valid. */,
- tempflag, bp_breakpoint,
- 0,
- AUTO_BOOLEAN_TRUE /* pending */,
- &gnu_v3_exception_catchpoint_ops, from_tty,
- 1 /* enabled */,
- 0 /* internal */,
- 0);
-
- return 1;
+ *string = last;
+ if (last_space > start)
+ return savestring (start, last_space - start);
+ return NULL;
}
/* Deal with "catch catch", "catch throw", and "catch rethrow"
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))
&& ex_event != EX_EVENT_RETHROW)
error (_("Unsupported or unknown exception event; cannot catch it"));
- if (handle_gnu_v3_exceptions (tempflag, cond_string, ex_event, from_tty))
- return;
+ handle_gnu_v3_exceptions (tempflag, except_rx, cond_string,
+ ex_event, from_tty);
- warning (_("Unsupported with this platform/compiler combination."));
+ discard_cleanups (cleanup);
}
/* Implementation of "catch catch" command. */
\f
+/* 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
+};
+
+\f
+
static void
initialize_throw_catchpoint_ops (void)
{
/* 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;
NULL,
CATCH_PERMANENT,
CATCH_TEMPORARY);
+
+ create_internalvar_type_lazy ("_exception", &exception_funcs, NULL);
}
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