gdb/break-catch-exec.c

   1 /* Everything about exec catchpoints, for GDB.
   2
   3    Copyright (C) 1986-2022 Free Software Foundation, Inc.
   4
   5    This file is part of GDB.
   6
   7    This program is free software; you can redistribute it and/or modify
   8    it under the terms of the GNU General Public License as published by
   9    the Free Software Foundation; either version 3 of the License, or
  10    (at your option) any later version.
  11
  12    This program is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15    GNU General Public License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  19
  20 #include "defs.h"
  21
  22 #include "annotate.h"
  23 #include "arch-utils.h"
  24 #include "breakpoint.h"
  25 #include "cli/cli-decode.h"
  26 #include "inferior.h"
  27 #include "mi/mi-common.h"
  28 #include "target.h"
  29 #include "valprint.h"
  30
  31 /* Exec catchpoints.  */
  32
  33 /* An instance of this type is used to represent an exec catchpoint.
  34    A breakpoint is really of this type iff its ops pointer points to
  35    CATCH_EXEC_BREAKPOINT_OPS.  */
  36
  37 struct exec_catchpoint : public catchpoint
  38 {
  39   exec_catchpoint (struct gdbarch *gdbarch, bool temp, const char *cond_string)
  40     : catchpoint (gdbarch, temp, cond_string)
  41   {
  42   }
  43
  44   int insert_location (struct bp_location *) override;
  45   int remove_location (struct bp_location *,
  46                        enum remove_bp_reason reason) override;
  47   int breakpoint_hit (const struct bp_location *bl,
  48                       const address_space *aspace,
  49                       CORE_ADDR bp_addr,
  50                       const target_waitstatus &ws) override;
  51   enum print_stop_action print_it (const bpstat *bs) const override;
  52   bool print_one (bp_location **) const override;
  53   void print_mention () const override;
  54   void print_recreate (struct ui_file *fp) const override;
  55
  56   /* Filename of a program whose exec triggered this catchpoint.
  57      This field is only valid immediately after this catchpoint has
  58      triggered.  */
  59   gdb::unique_xmalloc_ptr<char> exec_pathname;
  60 };
  61
  62 int
  63 exec_catchpoint::insert_location (struct bp_location *bl)
  64 {
  65   return target_insert_exec_catchpoint (inferior_ptid.pid ());
  66 }
  67
  68 int
  69 exec_catchpoint::remove_location (struct bp_location *bl,
  70                                   enum remove_bp_reason reason)
  71 {
  72   return target_remove_exec_catchpoint (inferior_ptid.pid ());
  73 }
  74
  75 int
  76 exec_catchpoint::breakpoint_hit (const struct bp_location *bl,
  77                                  const address_space *aspace,
  78                                  CORE_ADDR bp_addr,
  79                                  const target_waitstatus &ws)
  80 {
  81   if (ws.kind () != TARGET_WAITKIND_EXECD)
  82     return 0;
  83
  84   exec_pathname = make_unique_xstrdup (ws.execd_pathname ());
  85   return 1;
  86 }
  87
  88 enum print_stop_action
  89 exec_catchpoint::print_it (const bpstat *bs) const
  90 {
  91   struct ui_out *uiout = current_uiout;
  92
  93   annotate_catchpoint (number);
  94   maybe_print_thread_hit_breakpoint (uiout);
  95   if (disposition == disp_del)
  96     uiout->text ("Temporary catchpoint ");
  97   else
  98     uiout->text ("Catchpoint ");
  99   if (uiout->is_mi_like_p ())
 100     {
 101       uiout->field_string ("reason", async_reason_lookup (EXEC_ASYNC_EXEC));
 102       uiout->field_string ("disp", bpdisp_text (disposition));
 103     }
 104   uiout->field_signed ("bkptno", number);
 105   uiout->text (" (exec'd ");
 106   uiout->field_string ("new-exec", exec_pathname.get ());
 107   uiout->text ("), ");
 108
 109   return PRINT_SRC_AND_LOC;
 110 }
 111
 112 bool
 113 exec_catchpoint::print_one (bp_location **last_loc) const
 114 {
 115   struct value_print_options opts;
 116   struct ui_out *uiout = current_uiout;
 117
 118   get_user_print_options (&opts);
 119
 120   /* Field 4, the address, is omitted (which makes the columns
 121      not line up too nicely with the headers, but the effect
 122      is relatively readable).  */
 123   if (opts.addressprint)
 124     uiout->field_skip ("addr");
 125   annotate_field (5);
 126   uiout->text ("exec");
 127   if (exec_pathname != NULL)
 128     {
 129       uiout->text (", program \"");
 130       uiout->field_string ("what", exec_pathname.get ());
 131       uiout->text ("\" ");
 132     }
 133
 134   if (uiout->is_mi_like_p ())
 135     uiout->field_string ("catch-type", "exec");
 136
 137   return true;
 138 }
 139
 140 void
 141 exec_catchpoint::print_mention () const
 142 {
 143   gdb_printf (_("Catchpoint %d (exec)"), number);
 144 }
 145
 146 /* Implement the "print_recreate" method for exec catchpoints.  */
 147
 148 void
 149 exec_catchpoint::print_recreate (struct ui_file *fp) const
 150 {
 151   gdb_printf (fp, "catch exec");
 152   print_recreate_thread (fp);
 153 }
 154
 155 /* This function attempts to parse an optional "if <cond>" clause
 156    from the arg string.  If one is not found, it returns NULL.
 157
 158    Else, it returns a pointer to the condition string.  (It does not
 159    attempt to evaluate the string against a particular block.)  And,
 160    it updates arg to point to the first character following the parsed
 161    if clause in the arg string.  */
 162
 163 const char *
 164 ep_parse_optional_if_clause (const char **arg)
 165 {
 166   const char *cond_string;
 167
 168   if (((*arg)[0] != 'i') || ((*arg)[1] != 'f') || !isspace ((*arg)[2]))
 169     return NULL;
 170
 171   /* Skip the "if" keyword.  */
 172   (*arg) += 2;
 173
 174   /* Skip any extra leading whitespace, and record the start of the
 175      condition string.  */
 176   *arg = skip_spaces (*arg);
 177   cond_string = *arg;
 178
 179   /* Assume that the condition occupies the remainder of the arg
 180      string.  */
 181   (*arg) += strlen (cond_string);
 182
 183   return cond_string;
 184 }
 185
 186 /* Commands to deal with catching events, such as signals, exceptions,
 187    process start/exit, etc.  */
 188
 189 static void
 190 catch_exec_command_1 (const char *arg, int from_tty,
 191                       struct cmd_list_element *command)
 192 {
 193   struct gdbarch *gdbarch = get_current_arch ();
 194   const char *cond_string = NULL;
 195   bool temp = command->context () == CATCH_TEMPORARY;
 196
 197   if (!arg)
 198     arg = "";
 199   arg = skip_spaces (arg);
 200
 201   /* The allowed syntax is:
 202      catch exec
 203      catch exec if <cond>
 204
 205      First, check if there's an if clause.  */
 206   cond_string = ep_parse_optional_if_clause (&arg);
 207
 208   if ((*arg != '\0') && !isspace (*arg))
 209     error (_("Junk at end of arguments."));
 210
 211   std::unique_ptr<exec_catchpoint> c
 212     (new exec_catchpoint (gdbarch, temp, cond_string));
 213
 214   install_breakpoint (0, std::move (c), 1);
 215 }
 216
 217 void _initialize_break_catch_exec ();
 218 void
 219 _initialize_break_catch_exec ()
 220 {
 221   add_catch_command ("exec", _("Catch calls to exec."),
 222                      catch_exec_command_1,
 223                      NULL,
 224                      CATCH_PERMANENT,
 225                      CATCH_TEMPORARY);
 226 }