gdb/cp-abi.c

   1 /* Generic code for supporting multiple C++ ABI's
   2
   3    Copyright (C) 2001-2024 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 #include "language.h"
  22 #include "value.h"
  23 #include "cp-abi.h"
  24 #include "command.h"
  25 #include "gdbcmd.h"
  26 #include "ui-out.h"
  27 static struct cp_abi_ops *find_cp_abi (const char *short_name);
  28
  29 static struct cp_abi_ops current_cp_abi = { "", NULL };
  30 static struct cp_abi_ops auto_cp_abi = { "auto", NULL };
  31
  32 #define CP_ABI_MAX 8
  33 static struct cp_abi_ops *cp_abis[CP_ABI_MAX];
  34 static int num_cp_abis = 0;
  35
  36 enum ctor_kinds
  37 is_constructor_name (const char *name)
  38 {
  39   if ((current_cp_abi.is_constructor_name) == NULL)
  40     error (_("ABI doesn't define required function is_constructor_name"));
  41   return (*current_cp_abi.is_constructor_name) (name);
  42 }
  43
  44 enum dtor_kinds
  45 is_destructor_name (const char *name)
  46 {
  47   if ((current_cp_abi.is_destructor_name) == NULL)
  48     error (_("ABI doesn't define required function is_destructor_name"));
  49   return (*current_cp_abi.is_destructor_name) (name);
  50 }
  51
  52 int
  53 is_vtable_name (const char *name)
  54 {
  55   if ((current_cp_abi.is_vtable_name) == NULL)
  56     error (_("ABI doesn't define required function is_vtable_name"));
  57   return (*current_cp_abi.is_vtable_name) (name);
  58 }
  59
  60 int
  61 is_operator_name (const char *name)
  62 {
  63   if ((current_cp_abi.is_operator_name) == NULL)
  64     error (_("ABI doesn't define required function is_operator_name"));
  65   return (*current_cp_abi.is_operator_name) (name);
  66 }
  67
  68 int
  69 baseclass_offset (struct type *type, int index, const gdb_byte *valaddr,
  70                   LONGEST embedded_offset, CORE_ADDR address,
  71                   const struct value *val)
  72 {
  73   int res = 0;
  74
  75   gdb_assert (current_cp_abi.baseclass_offset != NULL);
  76
  77   try
  78     {
  79       res = (*current_cp_abi.baseclass_offset) (type, index, valaddr,
  80                                                 embedded_offset,
  81                                                 address, val);
  82     }
  83   catch (const gdb_exception_error &ex)
  84     {
  85       if (ex.error != NOT_AVAILABLE_ERROR)
  86         throw;
  87
  88       throw_error (NOT_AVAILABLE_ERROR,
  89                    _("Cannot determine virtual baseclass offset "
  90                      "of incomplete object"));
  91     }
  92
  93   return res;
  94 }
  95
  96 struct value *
  97 value_virtual_fn_field (struct value **arg1p,
  98                         struct fn_field *f, int j,
  99                         struct type *type, int offset)
 100 {
 101   if ((current_cp_abi.virtual_fn_field) == NULL)
 102     return NULL;
 103   return (*current_cp_abi.virtual_fn_field) (arg1p, f, j,
 104                                              type, offset);
 105 }
 106
 107 struct type *
 108 value_rtti_type (struct value *v, int *full,
 109                  LONGEST *top, int *using_enc)
 110 {
 111   struct type *ret = NULL;
 112
 113   if ((current_cp_abi.rtti_type) == NULL
 114       || !HAVE_CPLUS_STRUCT (check_typedef (v->type ())))
 115     return NULL;
 116   try
 117     {
 118       ret = (*current_cp_abi.rtti_type) (v, full, top, using_enc);
 119     }
 120   catch (const gdb_exception_error &e)
 121     {
 122       return NULL;
 123     }
 124
 125   return ret;
 126 }
 127
 128 void
 129 cplus_print_method_ptr (const gdb_byte *contents,
 130                         struct type *type,
 131                         struct ui_file *stream)
 132 {
 133   if (current_cp_abi.print_method_ptr == NULL)
 134     error (_("GDB does not support pointers to methods on this target"));
 135   (*current_cp_abi.print_method_ptr) (contents, type, stream);
 136 }
 137
 138 int
 139 cplus_method_ptr_size (struct type *to_type)
 140 {
 141   if (current_cp_abi.method_ptr_size == NULL)
 142     error (_("GDB does not support pointers to methods on this target"));
 143   return (*current_cp_abi.method_ptr_size) (to_type);
 144 }
 145
 146 void
 147 cplus_make_method_ptr (struct type *type, gdb_byte *contents,
 148                        CORE_ADDR value, int is_virtual)
 149 {
 150   if (current_cp_abi.make_method_ptr == NULL)
 151     error (_("GDB does not support pointers to methods on this target"));
 152   (*current_cp_abi.make_method_ptr) (type, contents, value, is_virtual);
 153 }
 154
 155 CORE_ADDR
 156 cplus_skip_trampoline (const frame_info_ptr &frame,
 157                        CORE_ADDR stop_pc)
 158 {
 159   if (current_cp_abi.skip_trampoline == NULL)
 160     return 0;
 161   return (*current_cp_abi.skip_trampoline) (frame, stop_pc);
 162 }
 163
 164 struct value *
 165 cplus_method_ptr_to_value (struct value **this_p,
 166                            struct value *method_ptr)
 167 {
 168   if (current_cp_abi.method_ptr_to_value == NULL)
 169     error (_("GDB does not support pointers to methods on this target"));
 170   return (*current_cp_abi.method_ptr_to_value) (this_p, method_ptr);
 171 }
 172
 173 /* See cp-abi.h.  */
 174
 175 void
 176 cplus_print_vtable (struct value *value)
 177 {
 178   if (current_cp_abi.print_vtable == NULL)
 179     error (_("GDB cannot print the vtable on this target"));
 180   (*current_cp_abi.print_vtable) (value);
 181 }
 182
 183 /* See cp-abi.h.  */
 184
 185 struct value *
 186 cplus_typeid (struct value *value)
 187 {
 188   if (current_cp_abi.get_typeid == NULL)
 189     error (_("GDB cannot find the typeid on this target"));
 190   return (*current_cp_abi.get_typeid) (value);
 191 }
 192
 193 /* See cp-abi.h.  */
 194
 195 struct type *
 196 cplus_typeid_type (struct gdbarch *gdbarch)
 197 {
 198   if (current_cp_abi.get_typeid_type == NULL)
 199     error (_("GDB cannot find the type for 'typeid' on this target"));
 200   return (*current_cp_abi.get_typeid_type) (gdbarch);
 201 }
 202
 203 /* See cp-abi.h.  */
 204
 205 struct type *
 206 cplus_type_from_type_info (struct value *value)
 207 {
 208   if (current_cp_abi.get_type_from_type_info == NULL)
 209     error (_("GDB cannot find the type from a std::type_info on this target"));
 210   return (*current_cp_abi.get_type_from_type_info) (value);
 211 }
 212
 213 /* See cp-abi.h.  */
 214
 215 std::string
 216 cplus_typename_from_type_info (struct value *value)
 217 {
 218   if (current_cp_abi.get_typename_from_type_info == NULL)
 219     error (_("GDB cannot find the type name "
 220              "from a std::type_info on this target"));
 221   return (*current_cp_abi.get_typename_from_type_info) (value);
 222 }
 223
 224 /* See cp-abi.h.  */
 225
 226 struct language_pass_by_ref_info
 227 cp_pass_by_reference (struct type *type)
 228 {
 229   if ((current_cp_abi.pass_by_reference) == NULL)
 230     return {};
 231   return (*current_cp_abi.pass_by_reference) (type);
 232 }
 233
 234 /* Set the current C++ ABI to SHORT_NAME.  */
 235
 236 static int
 237 switch_to_cp_abi (const char *short_name)
 238 {
 239   struct cp_abi_ops *abi;
 240
 241   abi = find_cp_abi (short_name);
 242   if (abi == NULL)
 243     return 0;
 244
 245   current_cp_abi = *abi;
 246   return 1;
 247 }
 248
 249 /* Add ABI to the list of supported C++ ABI's.  */
 250
 251 int
 252 register_cp_abi (struct cp_abi_ops *abi)
 253 {
 254   if (num_cp_abis == CP_ABI_MAX)
 255     internal_error (_("Too many C++ ABIs, please increase "
 256                       "CP_ABI_MAX in cp-abi.c"));
 257
 258   cp_abis[num_cp_abis++] = abi;
 259
 260   return 1;
 261 }
 262
 263 /* Set the ABI to use in "auto" mode to SHORT_NAME.  */
 264
 265 void
 266 set_cp_abi_as_auto_default (const char *short_name)
 267 {
 268   struct cp_abi_ops *abi = find_cp_abi (short_name);
 269
 270   if (abi == NULL)
 271     internal_error (_("Cannot find C++ ABI \"%s\" to set it as auto default."),
 272                     short_name);
 273
 274   xfree ((char *) auto_cp_abi.longname);
 275   xfree ((char *) auto_cp_abi.doc);
 276
 277   auto_cp_abi = *abi;
 278
 279   auto_cp_abi.shortname = "auto";
 280   auto_cp_abi.longname = xstrprintf ("currently \"%s\"",
 281                                      abi->shortname).release ();
 282   auto_cp_abi.doc = xstrprintf ("Automatically selected; currently \"%s\"",
 283                                 abi->shortname).release ();
 284
 285   /* Since we copy the current ABI into current_cp_abi instead of
 286      using a pointer, if auto is currently the default, we need to
 287      reset it.  */
 288   if (strcmp (current_cp_abi.shortname, "auto") == 0)
 289     switch_to_cp_abi ("auto");
 290 }
 291
 292 /* Return the ABI operations associated with SHORT_NAME.  */
 293
 294 static struct cp_abi_ops *
 295 find_cp_abi (const char *short_name)
 296 {
 297   int i;
 298
 299   for (i = 0; i < num_cp_abis; i++)
 300     if (strcmp (cp_abis[i]->shortname, short_name) == 0)
 301       return cp_abis[i];
 302
 303   return NULL;
 304 }
 305
 306 /* Display the list of registered C++ ABIs.  */
 307
 308 static void
 309 list_cp_abis (int from_tty)
 310 {
 311   struct ui_out *uiout = current_uiout;
 312   int i;
 313
 314   uiout->text ("The available C++ ABIs are:\n");
 315   ui_out_emit_tuple tuple_emitter (uiout, "cp-abi-list");
 316   for (i = 0; i < num_cp_abis; i++)
 317     {
 318       char pad[14];
 319       int padcount;
 320
 321       uiout->text ("  ");
 322       uiout->field_string ("cp-abi", cp_abis[i]->shortname);
 323
 324       padcount = 16 - 2 - strlen (cp_abis[i]->shortname);
 325       pad[padcount] = 0;
 326       while (padcount > 0)
 327         pad[--padcount] = ' ';
 328       uiout->text (pad);
 329
 330       uiout->field_string ("doc", cp_abis[i]->doc);
 331       uiout->text ("\n");
 332     }
 333 }
 334
 335 /* Set the current C++ ABI, or display the list of options if no
 336    argument is given.  */
 337
 338 static void
 339 set_cp_abi_cmd (const char *args, int from_tty)
 340 {
 341   if (args == NULL)
 342     {
 343       list_cp_abis (from_tty);
 344       return;
 345     }
 346
 347   if (!switch_to_cp_abi (args))
 348     error (_("Could not find \"%s\" in ABI list"), args);
 349 }
 350
 351 /* A completion function for "set cp-abi".  */
 352
 353 static void
 354 cp_abi_completer (struct cmd_list_element *ignore,
 355                   completion_tracker &tracker,
 356                   const char *text, const char *word)
 357 {
 358   static const char **cp_abi_names;
 359
 360   if (cp_abi_names == NULL)
 361     {
 362       int i;
 363
 364       cp_abi_names = XNEWVEC (const char *, num_cp_abis + 1);
 365       for (i = 0; i < num_cp_abis; ++i)
 366         cp_abi_names[i] = cp_abis[i]->shortname;
 367       cp_abi_names[i] = NULL;
 368     }
 369
 370   complete_on_enum (tracker, cp_abi_names, text, word);
 371 }
 372
 373 /* Show the currently selected C++ ABI.  */
 374
 375 static void
 376 show_cp_abi_cmd (const char *args, int from_tty)
 377 {
 378   struct ui_out *uiout = current_uiout;
 379
 380   uiout->text ("The currently selected C++ ABI is \"");
 381
 382   uiout->field_string ("cp-abi", current_cp_abi.shortname);
 383   uiout->text ("\" (");
 384   uiout->field_string ("longname", current_cp_abi.longname);
 385   uiout->text (").\n");
 386 }
 387
 388 void _initialize_cp_abi ();
 389 void
 390 _initialize_cp_abi ()
 391 {
 392   struct cmd_list_element *c;
 393
 394   register_cp_abi (&auto_cp_abi);
 395   switch_to_cp_abi ("auto");
 396
 397   c = add_cmd ("cp-abi", class_obscure, set_cp_abi_cmd, _("\
 398 Set the ABI used for inspecting C++ objects.\n\
 399 \"set cp-abi\" with no arguments will list the available ABIs."),
 400                &setlist);
 401   set_cmd_completer (c, cp_abi_completer);
 402
 403   add_cmd ("cp-abi", class_obscure, show_cp_abi_cmd,
 404            _("Show the ABI used for inspecting C++ objects."),
 405            &showlist);
 406 }