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