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 breakpoint
  38 {
  39   /* Filename of a program whose exec triggered this catchpoint.
  40      This field is only valid immediately after this catchpoint has
  41      triggered.  */
  42   gdb::unique_xmalloc_ptr<char> exec_pathname;
  43 };
  44
  45 static int
  46 insert_catch_exec (struct bp_location *bl)
  47 {
  48   return target_insert_exec_catchpoint (inferior_ptid.pid ());
  49 }
  50
  51 static int
  52 remove_catch_exec (struct bp_location *bl, enum remove_bp_reason reason)
  53 {
  54   return target_remove_exec_catchpoint (inferior_ptid.pid ());
  55 }
  56
  57 static int
  58 breakpoint_hit_catch_exec (const struct bp_location *bl,
  59                            const address_space *aspace, CORE_ADDR bp_addr,
  60                            const target_waitstatus &ws)
  61 {
  62   struct exec_catchpoint *c = (struct exec_catchpoint *) bl->owner;
  63
  64   if (ws.kind () != TARGET_WAITKIND_EXECD)
  65     return 0;
  66
  67   c->exec_pathname = make_unique_xstrdup (ws.execd_pathname ());
  68   return 1;
  69 }
  70
  71 static enum print_stop_action
  72 print_it_catch_exec (bpstat *bs)
  73 {
  74   struct ui_out *uiout = current_uiout;
  75   struct breakpoint *b = bs->breakpoint_at;
  76   struct exec_catchpoint *c = (struct exec_catchpoint *) b;
  77
  78   annotate_catchpoint (b->number);
  79   maybe_print_thread_hit_breakpoint (uiout);
  80   if (b->disposition == disp_del)
  81     uiout->text ("Temporary catchpoint ");
  82   else
  83     uiout->text ("Catchpoint ");
  84   if (uiout->is_mi_like_p ())
  85     {
  86       uiout->field_string ("reason", async_reason_lookup (EXEC_ASYNC_EXEC));
  87       uiout->field_string ("disp", bpdisp_text (b->disposition));
  88     }
  89   uiout->field_signed ("bkptno", b->number);
  90   uiout->text (" (exec'd ");
  91   uiout->field_string ("new-exec", c->exec_pathname.get ());
  92   uiout->text ("), ");
  93
  94   return PRINT_SRC_AND_LOC;
  95 }
  96
  97 static void
  98 print_one_catch_exec (struct breakpoint *b, struct bp_location **last_loc)
  99 {
 100   struct exec_catchpoint *c = (struct exec_catchpoint *) b;
 101   struct value_print_options opts;
 102   struct ui_out *uiout = current_uiout;
 103
 104   get_user_print_options (&opts);
 105
 106   /* Field 4, the address, is omitted (which makes the columns
 107      not line up too nicely with the headers, but the effect
 108      is relatively readable).  */
 109   if (opts.addressprint)
 110     uiout->field_skip ("addr");
 111   annotate_field (5);
 112   uiout->text ("exec");
 113   if (c->exec_pathname != NULL)
 114     {
 115       uiout->text (", program \"");
 116       uiout->field_string ("what", c->exec_pathname.get ());
 117       uiout->text ("\" ");
 118     }
 119
 120   if (uiout->is_mi_like_p ())
 121     uiout->field_string ("catch-type", "exec");
 122 }
 123
 124 static void
 125 print_mention_catch_exec (struct breakpoint *b)
 126 {
 127   printf_filtered (_("Catchpoint %d (exec)"), b->number);
 128 }
 129
 130 /* Implement the "print_recreate" breakpoint_ops method for exec
 131    catchpoints.  */
 132
 133 static void
 134 print_recreate_catch_exec (struct breakpoint *b, struct ui_file *fp)
 135 {
 136   fprintf_unfiltered (fp, "catch exec");
 137   print_recreate_thread (b, fp);
 138 }
 139
 140 static struct breakpoint_ops catch_exec_breakpoint_ops;
 141
 142 /* This function attempts to parse an optional "if <cond>" clause
 143    from the arg string.  If one is not found, it returns NULL.
 144
 145    Else, it returns a pointer to the condition string.  (It does not
 146    attempt to evaluate the string against a particular block.)  And,
 147    it updates arg to point to the first character following the parsed
 148    if clause in the arg string.  */
 149
 150 const char *
 151 ep_parse_optional_if_clause (const char **arg)
 152 {
 153   const char *cond_string;
 154
 155   if (((*arg)[0] != 'i') || ((*arg)[1] != 'f') || !isspace ((*arg)[2]))
 156     return NULL;
 157
 158   /* Skip the "if" keyword.  */
 159   (*arg) += 2;
 160
 161   /* Skip any extra leading whitespace, and record the start of the
 162      condition string.  */
 163   *arg = skip_spaces (*arg);
 164   cond_string = *arg;
 165
 166   /* Assume that the condition occupies the remainder of the arg
 167      string.  */
 168   (*arg) += strlen (cond_string);
 169
 170   return cond_string;
 171 }
 172
 173 /* Commands to deal with catching events, such as signals, exceptions,
 174    process start/exit, etc.  */
 175
 176 static void
 177 catch_exec_command_1 (const char *arg, int from_tty,
 178                       struct cmd_list_element *command)
 179 {
 180   struct gdbarch *gdbarch = get_current_arch ();
 181   const char *cond_string = NULL;
 182   bool temp = command->context () == CATCH_TEMPORARY;
 183
 184   if (!arg)
 185     arg = "";
 186   arg = skip_spaces (arg);
 187
 188   /* The allowed syntax is:
 189      catch exec
 190      catch exec if <cond>
 191
 192      First, check if there's an if clause.  */
 193   cond_string = ep_parse_optional_if_clause (&arg);
 194
 195   if ((*arg != '\0') && !isspace (*arg))
 196     error (_("Junk at end of arguments."));
 197
 198   std::unique_ptr<exec_catchpoint> c (new exec_catchpoint ());
 199   init_catchpoint (c.get (), gdbarch, temp, cond_string,
 200                    &catch_exec_breakpoint_ops);
 201   c->exec_pathname.reset ();
 202
 203   install_breakpoint (0, std::move (c), 1);
 204 }
 205
 206 static void
 207 initialize_ops ()
 208 {
 209   struct breakpoint_ops *ops;
 210
 211   initialize_breakpoint_ops ();
 212
 213   /* Exec catchpoints.  */
 214   ops = &catch_exec_breakpoint_ops;
 215   *ops = base_breakpoint_ops;
 216   ops->insert_location = insert_catch_exec;
 217   ops->remove_location = remove_catch_exec;
 218   ops->breakpoint_hit = breakpoint_hit_catch_exec;
 219   ops->print_it = print_it_catch_exec;
 220   ops->print_one = print_one_catch_exec;
 221   ops->print_mention = print_mention_catch_exec;
 222   ops->print_recreate = print_recreate_catch_exec;
 223 }
 224
 225 void _initialize_break_catch_exec ();
 226 void
 227 _initialize_break_catch_exec ()
 228 {
 229   initialize_ops ();
 230
 231   add_catch_command ("exec", _("Catch calls to exec."),
 232                      catch_exec_command_1,
 233                      NULL,
 234                      CATCH_PERMANENT,
 235                      CATCH_TEMPORARY);
 236 }