gdb/location.c

   1 /* Data structures and API for event locations in GDB.
   2    Copyright (C) 2013-2015 Free Software Foundation, Inc.
   3
   4    This file is part of GDB.
   5
   6    This program is free software; you can redistribute it and/or modify
   7    it under the terms of the GNU General Public License as published by
   8    the Free Software Foundation; either version 3 of the License, or
   9    (at your option) any later version.
  10
  11    This program is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14    GNU General Public License for more details.
  15
  16    You should have received a copy of the GNU General Public License
  17    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  18
  19 #include "defs.h"
  20 #include "gdb_assert.h"
  21 #include "location.h"
  22 #include "symtab.h"
  23 #include "language.h"
  24 #include "linespec.h"
  25 #include "cli/cli-utils.h"
  26 #include "probe.h"
  27
  28 #include <ctype.h>
  29 #include <string.h>
  30
  31 /* An event location used to set a stop event in the inferior.
  32    This structure is an amalgam of the various ways
  33    to specify where a stop event should be set.  */
  34
  35 struct event_location
  36 {
  37   /* The type of this breakpoint specification.  */
  38   enum event_location_type type;
  39 #define EL_TYPE(PTR) (PTR)->type
  40
  41   union
  42   {
  43     /* A generic "this is a string specification" for a location.
  44        This representation is used by both "normal" linespecs and
  45        probes.  */
  46     char *addr_string;
  47 #define EL_LINESPEC(PTR) ((PTR)->u.addr_string)
  48
  49     /* An address in the inferior.  */
  50     CORE_ADDR address;
  51 #define EL_ADDRESS(PTR) (PTR)->u.address
  52   } u;
  53
  54   /* Cached string representation of this location.  This is used, e.g., to
  55      save stop event locations to file.  Malloc'd.  */
  56   char *as_string;
  57 #define EL_STRING(PTR) ((PTR)->as_string)
  58 };
  59
  60 /* See description in location.h.  */
  61
  62 enum event_location_type
  63 event_location_type (const struct event_location *location)
  64 {
  65   return EL_TYPE (location);
  66 }
  67
  68 /* See description in location.h.  */
  69
  70 struct event_location *
  71 new_linespec_location (char **linespec)
  72 {
  73   struct event_location *location;
  74
  75   location = XCNEW (struct event_location);
  76   EL_TYPE (location) = LINESPEC_LOCATION;
  77   if (*linespec != NULL)
  78     {
  79       char *p;
  80       char *orig = *linespec;
  81
  82       linespec_lex_to_end (linespec);
  83       p = remove_trailing_whitespace (orig, *linespec);
  84       if ((p - orig) > 0)
  85         EL_LINESPEC (location) = savestring (orig, p - orig);
  86     }
  87   return location;
  88 }
  89
  90 /* See description in location.h.  */
  91
  92 const char *
  93 get_linespec_location (const struct event_location *location)
  94 {
  95   gdb_assert (EL_TYPE (location) == LINESPEC_LOCATION);
  96   return EL_LINESPEC (location);
  97 }
  98
  99 /* See description in location.h.  */
 100
 101 struct event_location *
 102 new_address_location (CORE_ADDR addr)
 103 {
 104   struct event_location *location;
 105
 106   location = XCNEW (struct event_location);
 107   EL_TYPE (location) = ADDRESS_LOCATION;
 108   EL_ADDRESS (location) = addr;
 109   return location;
 110 }
 111
 112 /* See description in location.h.  */
 113
 114 CORE_ADDR
 115 get_address_location (const struct event_location *location)
 116 {
 117   gdb_assert (EL_TYPE (location) == ADDRESS_LOCATION);
 118   return EL_ADDRESS (location);
 119 }
 120
 121 /* See description in location.h.  */
 122
 123 struct event_location *
 124 copy_event_location (const struct event_location *src)
 125 {
 126   struct event_location *dst;
 127
 128   dst = XCNEW (struct event_location);
 129   EL_TYPE (dst) = EL_TYPE (src);
 130   if (EL_STRING (src) != NULL)
 131     EL_STRING (dst) = xstrdup (EL_STRING (src));
 132
 133   switch (EL_TYPE (src))
 134     {
 135     case LINESPEC_LOCATION:
 136       if (EL_LINESPEC (src) != NULL)
 137         EL_LINESPEC (dst) = xstrdup (EL_LINESPEC (src));
 138       break;
 139
 140     case ADDRESS_LOCATION:
 141       EL_ADDRESS (dst) = EL_ADDRESS (src);
 142       break;
 143
 144     default:
 145       gdb_assert_not_reached ("unknown event location type");
 146     }
 147
 148   return dst;
 149 }
 150
 151 /* A cleanup function for struct event_location.  */
 152
 153 static void
 154 delete_event_location_cleanup (void *data)
 155 {
 156   struct event_location *location = (struct event_location *) data;
 157
 158   delete_event_location (location);
 159 }
 160
 161 /* See description in location.h.  */
 162
 163 struct cleanup *
 164 make_cleanup_delete_event_location (struct event_location *location)
 165 {
 166   return make_cleanup (delete_event_location_cleanup, location);
 167 }
 168
 169 /* See description in location.h.  */
 170
 171 void
 172 delete_event_location (struct event_location *location)
 173 {
 174   if (location != NULL)
 175     {
 176       xfree (EL_STRING (location));
 177
 178       switch (EL_TYPE (location))
 179         {
 180         case LINESPEC_LOCATION:
 181           xfree (EL_LINESPEC (location));
 182           break;
 183
 184         case ADDRESS_LOCATION:
 185           /* Nothing to do.  */
 186           break;
 187
 188         default:
 189           gdb_assert_not_reached ("unknown event location type");
 190         }
 191
 192       xfree (location);
 193     }
 194 }
 195
 196 /* See description in location.h.  */
 197
 198 const char *
 199 event_location_to_string (struct event_location *location)
 200 {
 201   if (EL_STRING (location) == NULL)
 202     {
 203       switch (EL_TYPE (location))
 204         {
 205         case LINESPEC_LOCATION:
 206           if (EL_LINESPEC (location) != NULL)
 207             EL_STRING (location) = xstrdup (EL_LINESPEC (location));
 208           break;
 209
 210         case ADDRESS_LOCATION:
 211           EL_STRING (location)
 212             = xstrprintf ("*%s",
 213                           core_addr_to_string (EL_ADDRESS (location)));
 214           break;
 215
 216         default:
 217           gdb_assert_not_reached ("unknown event location type");
 218         }
 219     }
 220
 221   return EL_STRING (location);
 222 }
 223
 224 /* See description in location.h.  */
 225
 226 struct event_location *
 227 string_to_event_location (char **stringp,
 228                           const struct language_defn *language)
 229 {
 230   struct event_location *location;
 231
 232   /* First, check if the string is an address location.  */
 233   if (*stringp != NULL && **stringp == '*')
 234     {
 235       const char *arg, *orig;
 236       CORE_ADDR addr;
 237
 238       orig = arg = *stringp;
 239       addr = linespec_expression_to_pc (&arg);
 240       location = new_address_location (addr);
 241       *stringp += arg - orig;
 242     }
 243   else
 244     {
 245       /* Everything else is a linespec.  */
 246       location = new_linespec_location (stringp);
 247     }
 248
 249   return location;
 250 }
 251
 252 /* See description in location.h.  */
 253
 254 int
 255 event_location_empty_p (const struct event_location *location)
 256 {
 257   switch (EL_TYPE (location))
 258     {
 259     case LINESPEC_LOCATION:
 260       /* Linespecs are never "empty."  (NULL is a valid linespec)  */
 261       return 0;
 262
 263     case ADDRESS_LOCATION:
 264       return 0;
 265
 266     default:
 267       gdb_assert_not_reached ("unknown event location type");
 268     }
 269 }
 270
 271 /* See description in location.h.  */
 272
 273 void
 274 set_event_location_string (struct event_location *location,
 275                            const char *string)
 276 {
 277   xfree (EL_STRING (location));
 278   EL_STRING (location) = string == NULL ?  NULL : xstrdup (string);
 279 }