mirror of
https://sourceware.org/git/binutils-gdb.git
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6cb06a8cda
Now that filtered and unfiltered output can be treated identically, we can unify the printf family of functions. This is done under the name "gdb_printf". Most of this patch was written by script.
565 lines
15 KiB
C
565 lines
15 KiB
C
/* Everything about catch/throw catchpoints, for GDB.
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Copyright (C) 1986-2022 Free Software Foundation, Inc.
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This file is part of GDB.
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 3 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program. If not, see <http://www.gnu.org/licenses/>. */
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#include "defs.h"
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#include "arch-utils.h"
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#include <ctype.h>
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#include "breakpoint.h"
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#include "gdbcmd.h"
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#include "inferior.h"
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#include "annotate.h"
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#include "valprint.h"
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#include "cli/cli-utils.h"
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#include "completer.h"
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#include "gdbsupport/gdb_obstack.h"
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#include "mi/mi-common.h"
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#include "linespec.h"
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#include "probe.h"
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#include "objfiles.h"
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#include "cp-abi.h"
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#include "gdbsupport/gdb_regex.h"
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#include "cp-support.h"
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#include "location.h"
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#include "cli/cli-decode.h"
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/* Each spot where we may place an exception-related catchpoint has
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two names: the SDT probe point and the function name. This
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structure holds both. */
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struct exception_names
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{
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/* The name of the probe point to try, in the form accepted by
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'parse_probes'. */
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const char *probe;
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/* The name of the corresponding function. */
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const char *function;
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};
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/* Names of the probe points and functions on which to break. This is
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indexed by exception_event_kind. */
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static const struct exception_names exception_functions[] =
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{
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{ "-probe-stap libstdcxx:throw", "__cxa_throw" },
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{ "-probe-stap libstdcxx:rethrow", "__cxa_rethrow" },
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{ "-probe-stap libstdcxx:catch", "__cxa_begin_catch" }
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};
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static struct breakpoint_ops gnu_v3_exception_catchpoint_ops;
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/* The type of an exception catchpoint. */
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struct exception_catchpoint : public breakpoint
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{
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/* The kind of exception catchpoint. */
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enum exception_event_kind kind;
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/* If not empty, a string holding the source form of the regular
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expression to match against. */
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std::string exception_rx;
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/* If non-NULL, a compiled regular expression which is used to
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determine which exceptions to stop on. */
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std::unique_ptr<compiled_regex> pattern;
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};
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/* See breakpoint.h. */
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bool
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is_exception_catchpoint (breakpoint *bp)
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{
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return bp->ops == &gnu_v3_exception_catchpoint_ops;
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}
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/* A helper function that fetches exception probe arguments. This
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fills in *ARG0 (if non-NULL) and *ARG1 (which must be non-NULL).
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It will throw an exception on any kind of failure. */
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static void
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fetch_probe_arguments (struct value **arg0, struct value **arg1)
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{
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struct frame_info *frame = get_selected_frame (_("No frame selected"));
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CORE_ADDR pc = get_frame_pc (frame);
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struct bound_probe pc_probe;
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unsigned n_args;
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pc_probe = find_probe_by_pc (pc);
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if (pc_probe.prob == NULL)
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error (_("did not find exception probe (does libstdcxx have SDT probes?)"));
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if (pc_probe.prob->get_provider () != "libstdcxx"
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|| (pc_probe.prob->get_name () != "catch"
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&& pc_probe.prob->get_name () != "throw"
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&& pc_probe.prob->get_name () != "rethrow"))
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error (_("not stopped at a C++ exception catchpoint"));
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n_args = pc_probe.prob->get_argument_count (get_frame_arch (frame));
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if (n_args < 2)
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error (_("C++ exception catchpoint has too few arguments"));
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if (arg0 != NULL)
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*arg0 = pc_probe.prob->evaluate_argument (0, frame);
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*arg1 = pc_probe.prob->evaluate_argument (1, frame);
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if ((arg0 != NULL && *arg0 == NULL) || *arg1 == NULL)
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error (_("error computing probe argument at c++ exception catchpoint"));
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}
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/* A helper function that returns a value indicating the kind of the
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exception catchpoint B. */
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static enum exception_event_kind
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classify_exception_breakpoint (struct breakpoint *b)
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{
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struct exception_catchpoint *cp = (struct exception_catchpoint *) b;
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return cp->kind;
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}
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/* Implement the 'check_status' method. */
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static void
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check_status_exception_catchpoint (struct bpstat *bs)
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{
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struct exception_catchpoint *self
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= (struct exception_catchpoint *) bs->breakpoint_at;
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std::string type_name;
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bkpt_breakpoint_ops.check_status (bs);
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if (bs->stop == 0)
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return;
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if (self->pattern == NULL)
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return;
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const char *name = nullptr;
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gdb::unique_xmalloc_ptr<char> canon;
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try
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{
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struct value *typeinfo_arg;
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fetch_probe_arguments (NULL, &typeinfo_arg);
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type_name = cplus_typename_from_type_info (typeinfo_arg);
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canon = cp_canonicalize_string (type_name.c_str ());
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name = (canon != nullptr
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? canon.get ()
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: type_name.c_str ());
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}
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catch (const gdb_exception_error &e)
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{
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exception_print (gdb_stderr, e);
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}
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if (name != nullptr)
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{
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if (self->pattern->exec (name, 0, NULL, 0) != 0)
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bs->stop = 0;
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}
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}
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/* Implement the 're_set' method. */
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static void
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re_set_exception_catchpoint (struct breakpoint *self)
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{
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std::vector<symtab_and_line> sals;
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enum exception_event_kind kind = classify_exception_breakpoint (self);
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struct program_space *filter_pspace = current_program_space;
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/* We first try to use the probe interface. */
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try
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{
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event_location_up location
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= new_probe_location (exception_functions[kind].probe);
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sals = parse_probes (location.get (), filter_pspace, NULL);
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}
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catch (const gdb_exception_error &e)
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{
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/* Using the probe interface failed. Let's fallback to the normal
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catchpoint mode. */
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try
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{
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struct explicit_location explicit_loc;
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initialize_explicit_location (&explicit_loc);
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explicit_loc.function_name
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= ASTRDUP (exception_functions[kind].function);
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event_location_up location = new_explicit_location (&explicit_loc);
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sals = self->ops->decode_location (self, location.get (),
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filter_pspace);
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}
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catch (const gdb_exception_error &ex)
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{
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/* NOT_FOUND_ERROR just means the breakpoint will be
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pending, so let it through. */
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if (ex.error != NOT_FOUND_ERROR)
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throw;
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}
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}
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update_breakpoint_locations (self, filter_pspace, sals, {});
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}
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static enum print_stop_action
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print_it_exception_catchpoint (bpstat *bs)
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{
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struct ui_out *uiout = current_uiout;
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struct breakpoint *b = bs->breakpoint_at;
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int bp_temp;
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enum exception_event_kind kind = classify_exception_breakpoint (b);
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annotate_catchpoint (b->number);
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maybe_print_thread_hit_breakpoint (uiout);
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bp_temp = b->disposition == disp_del;
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uiout->text (bp_temp ? "Temporary catchpoint "
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: "Catchpoint ");
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uiout->field_signed ("bkptno", b->number);
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uiout->text ((kind == EX_EVENT_THROW ? " (exception thrown), "
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: (kind == EX_EVENT_CATCH ? " (exception caught), "
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: " (exception rethrown), ")));
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if (uiout->is_mi_like_p ())
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{
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uiout->field_string ("reason",
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async_reason_lookup (EXEC_ASYNC_BREAKPOINT_HIT));
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uiout->field_string ("disp", bpdisp_text (b->disposition));
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}
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return PRINT_SRC_AND_LOC;
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}
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static void
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print_one_exception_catchpoint (struct breakpoint *b,
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struct bp_location **last_loc)
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{
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struct value_print_options opts;
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struct ui_out *uiout = current_uiout;
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enum exception_event_kind kind = classify_exception_breakpoint (b);
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get_user_print_options (&opts);
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if (opts.addressprint)
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uiout->field_skip ("addr");
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annotate_field (5);
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switch (kind)
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{
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case EX_EVENT_THROW:
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uiout->field_string ("what", "exception throw");
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if (uiout->is_mi_like_p ())
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uiout->field_string ("catch-type", "throw");
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break;
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case EX_EVENT_RETHROW:
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uiout->field_string ("what", "exception rethrow");
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if (uiout->is_mi_like_p ())
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uiout->field_string ("catch-type", "rethrow");
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break;
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case EX_EVENT_CATCH:
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uiout->field_string ("what", "exception catch");
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if (uiout->is_mi_like_p ())
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uiout->field_string ("catch-type", "catch");
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break;
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}
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}
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/* Implement the 'print_one_detail' method. */
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static void
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print_one_detail_exception_catchpoint (const struct breakpoint *b,
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struct ui_out *uiout)
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{
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const struct exception_catchpoint *cp
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= (const struct exception_catchpoint *) b;
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if (!cp->exception_rx.empty ())
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{
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uiout->text (_("\tmatching: "));
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uiout->field_string ("regexp", cp->exception_rx);
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uiout->text ("\n");
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}
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}
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static void
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print_mention_exception_catchpoint (struct breakpoint *b)
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{
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struct ui_out *uiout = current_uiout;
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int bp_temp;
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enum exception_event_kind kind = classify_exception_breakpoint (b);
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bp_temp = b->disposition == disp_del;
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uiout->message ("%s %d %s",
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(bp_temp ? _("Temporary catchpoint ") : _("Catchpoint")),
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b->number,
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(kind == EX_EVENT_THROW
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? _("(throw)") : (kind == EX_EVENT_CATCH
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? _("(catch)") : _("(rethrow)"))));
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}
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/* Implement the "print_recreate" breakpoint_ops method for throw and
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catch catchpoints. */
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static void
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print_recreate_exception_catchpoint (struct breakpoint *b,
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struct ui_file *fp)
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{
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int bp_temp;
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enum exception_event_kind kind = classify_exception_breakpoint (b);
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bp_temp = b->disposition == disp_del;
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gdb_printf (fp, bp_temp ? "tcatch " : "catch ");
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switch (kind)
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{
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case EX_EVENT_THROW:
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gdb_printf (fp, "throw");
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break;
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case EX_EVENT_CATCH:
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gdb_printf (fp, "catch");
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break;
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case EX_EVENT_RETHROW:
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gdb_printf (fp, "rethrow");
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break;
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}
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print_recreate_thread (b, fp);
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}
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/* Implement the "allocate_location" breakpoint_ops method for throw
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and catch catchpoints. */
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static bp_location *
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allocate_location_exception_catchpoint (breakpoint *self)
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{
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return new bp_location (self, bp_loc_software_breakpoint);
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}
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static void
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handle_gnu_v3_exceptions (int tempflag, std::string &&except_rx,
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const char *cond_string,
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enum exception_event_kind ex_event, int from_tty)
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{
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std::unique_ptr<compiled_regex> pattern;
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if (!except_rx.empty ())
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{
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pattern.reset (new compiled_regex (except_rx.c_str (), REG_NOSUB,
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_("invalid type-matching regexp")));
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}
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std::unique_ptr<exception_catchpoint> cp (new exception_catchpoint ());
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init_catchpoint (cp.get (), get_current_arch (), tempflag, cond_string,
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&gnu_v3_exception_catchpoint_ops);
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cp->kind = ex_event;
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cp->exception_rx = std::move (except_rx);
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cp->pattern = std::move (pattern);
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re_set_exception_catchpoint (cp.get ());
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install_breakpoint (0, std::move (cp), 1);
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}
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/* Look for an "if" token in *STRING. The "if" token must be preceded
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by whitespace.
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If there is any non-whitespace text between *STRING and the "if"
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token, then it is returned in a newly-xmalloc'd string. Otherwise,
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this returns NULL.
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STRING is updated to point to the "if" token, if it exists, or to
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the end of the string. */
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static std::string
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extract_exception_regexp (const char **string)
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{
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const char *start;
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const char *last, *last_space;
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start = skip_spaces (*string);
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last = start;
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last_space = start;
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while (*last != '\0')
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{
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const char *if_token = last;
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/* Check for the "if". */
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if (check_for_argument (&if_token, "if", 2))
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break;
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/* No "if" token here. Skip to the next word start. */
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last_space = skip_to_space (last);
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last = skip_spaces (last_space);
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}
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*string = last;
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if (last_space > start)
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return std::string (start, last_space - start);
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return std::string ();
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}
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/* See breakpoint.h. */
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void
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catch_exception_event (enum exception_event_kind ex_event,
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const char *arg, bool tempflag, int from_tty)
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{
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const char *cond_string = NULL;
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if (!arg)
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arg = "";
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arg = skip_spaces (arg);
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std::string except_rx = extract_exception_regexp (&arg);
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cond_string = ep_parse_optional_if_clause (&arg);
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if ((*arg != '\0') && !isspace (*arg))
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error (_("Junk at end of arguments."));
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if (ex_event != EX_EVENT_THROW
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&& ex_event != EX_EVENT_CATCH
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&& ex_event != EX_EVENT_RETHROW)
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error (_("Unsupported or unknown exception event; cannot catch it"));
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handle_gnu_v3_exceptions (tempflag, std::move (except_rx), cond_string,
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ex_event, from_tty);
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}
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/* Implementation of "catch catch" command. */
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static void
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catch_catch_command (const char *arg, int from_tty,
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struct cmd_list_element *command)
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{
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bool tempflag = command->context () == CATCH_TEMPORARY;
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catch_exception_event (EX_EVENT_CATCH, arg, tempflag, from_tty);
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}
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/* Implementation of "catch throw" command. */
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static void
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catch_throw_command (const char *arg, int from_tty,
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struct cmd_list_element *command)
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{
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bool tempflag = command->context () == CATCH_TEMPORARY;
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catch_exception_event (EX_EVENT_THROW, arg, tempflag, from_tty);
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}
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/* Implementation of "catch rethrow" command. */
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static void
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catch_rethrow_command (const char *arg, int from_tty,
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struct cmd_list_element *command)
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{
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bool tempflag = command->context () == CATCH_TEMPORARY;
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catch_exception_event (EX_EVENT_RETHROW, arg, tempflag, from_tty);
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}
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/* Implement the 'make_value' method for the $_exception
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internalvar. */
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static struct value *
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compute_exception (struct gdbarch *argc, struct internalvar *var, void *ignore)
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{
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struct value *arg0, *arg1;
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struct type *obj_type;
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fetch_probe_arguments (&arg0, &arg1);
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/* ARG0 is a pointer to the exception object. ARG1 is a pointer to
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the std::type_info for the exception. Now we find the type from
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the type_info and cast the result. */
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obj_type = cplus_type_from_type_info (arg1);
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return value_ind (value_cast (make_pointer_type (obj_type, NULL), arg0));
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}
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/* Implementation of the '$_exception' variable. */
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static const struct internalvar_funcs exception_funcs =
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{
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compute_exception,
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NULL,
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};
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static void
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initialize_throw_catchpoint_ops (void)
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{
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struct breakpoint_ops *ops;
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initialize_breakpoint_ops ();
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/* GNU v3 exception catchpoints. */
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ops = &gnu_v3_exception_catchpoint_ops;
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*ops = bkpt_breakpoint_ops;
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ops->re_set = re_set_exception_catchpoint;
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ops->print_it = print_it_exception_catchpoint;
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ops->print_one = print_one_exception_catchpoint;
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ops->print_mention = print_mention_exception_catchpoint;
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ops->print_recreate = print_recreate_exception_catchpoint;
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ops->print_one_detail = print_one_detail_exception_catchpoint;
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ops->check_status = check_status_exception_catchpoint;
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ops->allocate_location = allocate_location_exception_catchpoint;
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}
|
||
|
||
void _initialize_break_catch_throw ();
|
||
void
|
||
_initialize_break_catch_throw ()
|
||
{
|
||
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);
|
||
}
|