gdb/cp-abi.c

   1 /* Generic code for supporting multiple C++ ABI's
   2
   3    Copyright (C) 2001-2021 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 "value.h"
  22 #include "cp-abi.h"
  23 #include "command.h"
  24 #include "gdbcmd.h"
  25 #include "ui-out.h"
  26 static struct cp_abi_ops *find_cp_abi (const char *short_name);
  27
  28 static struct cp_abi_ops current_cp_abi = { "", NULL };
  29 static struct cp_abi_ops auto_cp_abi = { "auto", NULL };
  30
  31 #define CP_ABI_MAX 8
  32 static struct cp_abi_ops *cp_abis[CP_ABI_MAX];
  33 static int num_cp_abis = 0;
  34
  35 enum ctor_kinds
  36 is_constructor_name (const char *name)
  37 {
  38   if ((current_cp_abi.is_constructor_name) == NULL)
  39     error (_("ABI doesn't define required function is_constructor_name"));
  40   return (*current_cp_abi.is_constructor_name) (name);
  41 }
  42
  43 enum dtor_kinds
  44 is_destructor_name (const char *name)
  45 {
  46   if ((current_cp_abi.is_destructor_name) == NULL)
  47     error (_("ABI doesn't define required function is_destructor_name"));
  48   return (*current_cp_abi.is_destructor_name) (name);
  49 }
  50
  51 int
  52 is_vtable_name (const char *name)
  53 {
  54   if ((current_cp_abi.is_vtable_name) == NULL)
  55     error (_("ABI doesn't define required function is_vtable_name"));
  56   return (*current_cp_abi.is_vtable_name) (name);
  57 }
  58
  59 int
  60 is_operator_name (const char *name)
  61 {
  62   if ((current_cp_abi.is_operator_name) == NULL)
  63     error (_("ABI doesn't define required function is_operator_name"));
  64   return (*current_cp_abi.is_operator_name) (name);
  65 }
  66
  67 int
  68 baseclass_offset (struct type *type, int index, const gdb_byte *valaddr,
  69                   LONGEST embedded_offset, CORE_ADDR address,
  70                   const struct value *val)
  71 {
  72   int res = 0;
  73
  74   gdb_assert (current_cp_abi.baseclass_offset != NULL);
  75
  76   try
  77     {
  78       res = (*current_cp_abi.baseclass_offset) (type, index, valaddr,
  79                                                 embedded_offset,
  80                                                 address, val);
  81     }
  82   catch (const gdb_exception_error &ex)
  83     {
  84       if (ex.error != NOT_AVAILABLE_ERROR)
  85         throw;
  86
  87       throw_error (NOT_AVAILABLE_ERROR,
  88                    _("Cannot determine virtual baseclass offset "
  89                      "of incomplete object"));
  90     }
  91
  92   return res;
  93 }
  94
  95 struct value *
  96 value_virtual_fn_field (struct value **arg1p,
  97                         struct fn_field *f, int j,
  98                         struct type *type, int offset)
  99 {
 100   if ((current_cp_abi.virtual_fn_field) == NULL)
 101     return NULL;
 102   return (*current_cp_abi.virtual_fn_field) (arg1p, f, j,
 103                                              type, offset);
 104 }
 105
 106 struct type *
 107 value_rtti_type (struct value *v, int *full,
 108                  LONGEST *top, int *using_enc)
 109 {
 110   struct type *ret = NULL;
 111
 112   if ((current_cp_abi.rtti_type) == NULL
 113       || !HAVE_CPLUS_STRUCT (check_typedef (value_type (v))))
 114     return NULL;
 115   try
 116     {
 117       ret = (*current_cp_abi.rtti_type) (v, full, top, using_enc);
 118     }
 119   catch (const gdb_exception_error &e)
 120     {
 121       return NULL;
 122     }
 123
 124   return ret;
 125 }
 126
 127 void
 128 cplus_print_method_ptr (const gdb_byte *contents,
 129                         struct type *type,
 130                         struct ui_file *stream)
 131 {
 132   if (current_cp_abi.print_method_ptr == NULL)
 133     error (_("GDB does not support pointers to methods on this target"));
 134   (*current_cp_abi.print_method_ptr) (contents, type, stream);
 135 }
 136
 137 int
 138 cplus_method_ptr_size (struct type *to_type)
 139 {
 140   if (current_cp_abi.method_ptr_size == NULL)
 141     error (_("GDB does not support pointers to methods on this target"));
 142   return (*current_cp_abi.method_ptr_size) (to_type);
 143 }
 144
 145 void
 146 cplus_make_method_ptr (struct type *type, gdb_byte *contents,
 147                        CORE_ADDR value, int is_virtual)
 148 {
 149   if (current_cp_abi.make_method_ptr == NULL)
 150     error (_("GDB does not support pointers to methods on this target"));
 151   (*current_cp_abi.make_method_ptr) (type, contents, value, is_virtual);
 152 }
 153
 154 CORE_ADDR
 155 cplus_skip_trampoline (struct frame_info *frame,
 156                        CORE_ADDR stop_pc)
 157 {
 158   if (current_cp_abi.skip_trampoline == NULL)
 159     return 0;
 160   return (*current_cp_abi.skip_trampoline) (frame, stop_pc);
 161 }
 162
 163 struct value *
 164 cplus_method_ptr_to_value (struct value **this_p,
 165                            struct value *method_ptr)
 166 {
 167   if (current_cp_abi.method_ptr_to_value == NULL)
 168     error (_("GDB does not support pointers to methods on this target"));
 169   return (*current_cp_abi.method_ptr_to_value) (this_p, method_ptr);
 170 }
 171
 172 /* See cp-abi.h.  */
 173
 174 void
 175 cplus_print_vtable (struct value *value)
 176 {
 177   if (current_cp_abi.print_vtable == NULL)
 178     error (_("GDB cannot print the vtable on this target"));
 179   (*current_cp_abi.print_vtable) (value);
 180 }
 181
 182 /* See cp-abi.h.  */
 183
 184 struct value *
 185 cplus_typeid (struct value *value)
 186 {
 187   if (current_cp_abi.get_typeid == NULL)
 188     error (_("GDB cannot find the typeid on this target"));
 189   return (*current_cp_abi.get_typeid) (value);
 190 }
 191
 192 /* See cp-abi.h.  */
 193
 194 struct type *
 195 cplus_typeid_type (struct gdbarch *gdbarch)
 196 {
 197   if (current_cp_abi.get_typeid_type == NULL)
 198     error (_("GDB cannot find the type for 'typeid' on this target"));
 199   return (*current_cp_abi.get_typeid_type) (gdbarch);
 200 }
 201
 202 /* See cp-abi.h.  */
 203
 204 struct type *
 205 cplus_type_from_type_info (struct value *value)
 206 {
 207   if (current_cp_abi.get_type_from_type_info == NULL)
 208     error (_("GDB cannot find the type from a std::type_info on this target"));
 209   return (*current_cp_abi.get_type_from_type_info) (value);
 210 }
 211
 212 /* See cp-abi.h.  */
 213
 214 std::string
 215 cplus_typename_from_type_info (struct value *value)
 216 {
 217   if (current_cp_abi.get_typename_from_type_info == NULL)
 218     error (_("GDB cannot find the type name "
 219              "from a std::type_info on this target"));
 220   return (*current_cp_abi.get_typename_from_type_info) (value);
 221 }
 222
 223 /* See cp-abi.h.  */
 224
 225 struct language_pass_by_ref_info
 226 cp_pass_by_reference (struct type *type)
 227 {
 228   if ((current_cp_abi.pass_by_reference) == NULL)
 229     return {};
 230   return (*current_cp_abi.pass_by_reference) (type);
 231 }
 232
 233 /* Set the current C++ ABI to SHORT_NAME.  */
 234
 235 static int
 236 switch_to_cp_abi (const char *short_name)
 237 {
 238   struct cp_abi_ops *abi;
 239
 240   abi = find_cp_abi (short_name);
 241   if (abi == NULL)
 242     return 0;
 243
 244   current_cp_abi = *abi;
 245   return 1;
 246 }
 247
 248 /* Add ABI to the list of supported C++ ABI's.  */
 249
 250 int
 251 register_cp_abi (struct cp_abi_ops *abi)
 252 {
 253   if (num_cp_abis == CP_ABI_MAX)
 254     internal_error (__FILE__, __LINE__,
 255                     _("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   char *new_longname, *new_doc;
 269   struct cp_abi_ops *abi = find_cp_abi (short_name);
 270
 271   if (abi == NULL)
 272     internal_error (__FILE__, __LINE__,
 273                     _("Cannot find C++ ABI \"%s\" to set it as auto default."),
 274                     short_name);
 275
 276   xfree ((char *) auto_cp_abi.longname);
 277   xfree ((char *) auto_cp_abi.doc);
 278
 279   auto_cp_abi = *abi;
 280
 281   auto_cp_abi.shortname = "auto";
 282   new_longname = xstrprintf ("currently \"%s\"", abi->shortname);
 283   auto_cp_abi.longname = new_longname;
 284
 285   new_doc = xstrprintf ("Automatically selected; currently \"%s\"",
 286              abi->shortname);
 287   auto_cp_abi.doc = new_doc;
 288
 289   /* Since we copy the current ABI into current_cp_abi instead of
 290      using a pointer, if auto is currently the default, we need to
 291      reset it.  */
 292   if (strcmp (current_cp_abi.shortname, "auto") == 0)
 293     switch_to_cp_abi ("auto");
 294 }
 295
 296 /* Return the ABI operations associated with SHORT_NAME.  */
 297
 298 static struct cp_abi_ops *
 299 find_cp_abi (const char *short_name)
 300 {
 301   int i;
 302
 303   for (i = 0; i < num_cp_abis; i++)
 304     if (strcmp (cp_abis[i]->shortname, short_name) == 0)
 305       return cp_abis[i];
 306
 307   return NULL;
 308 }
 309
 310 /* Display the list of registered C++ ABIs.  */
 311
 312 static void
 313 list_cp_abis (int from_tty)
 314 {
 315   struct ui_out *uiout = current_uiout;
 316   int i;
 317
 318   uiout->text ("The available C++ ABIs are:\n");
 319   ui_out_emit_tuple tuple_emitter (uiout, "cp-abi-list");
 320   for (i = 0; i < num_cp_abis; i++)
 321     {
 322       char pad[14];
 323       int padcount;
 324
 325       uiout->text ("  ");
 326       uiout->field_string ("cp-abi", cp_abis[i]->shortname);
 327
 328       padcount = 16 - 2 - strlen (cp_abis[i]->shortname);
 329       pad[padcount] = 0;
 330       while (padcount > 0)
 331         pad[--padcount] = ' ';
 332       uiout->text (pad);
 333
 334       uiout->field_string ("doc", cp_abis[i]->doc);
 335       uiout->text ("\n");
 336     }
 337 }
 338
 339 /* Set the current C++ ABI, or display the list of options if no
 340    argument is given.  */
 341
 342 static void
 343 set_cp_abi_cmd (const char *args, int from_tty)
 344 {
 345   if (args == NULL)
 346     {
 347       list_cp_abis (from_tty);
 348       return;
 349     }
 350
 351   if (!switch_to_cp_abi (args))
 352     error (_("Could not find \"%s\" in ABI list"), args);
 353 }
 354
 355 /* A completion function for "set cp-abi".  */
 356
 357 static void
 358 cp_abi_completer (struct cmd_list_element *ignore,
 359                   completion_tracker &tracker,
 360                   const char *text, const char *word)
 361 {
 362   static const char **cp_abi_names;
 363
 364   if (cp_abi_names == NULL)
 365     {
 366       int i;
 367
 368       cp_abi_names = XNEWVEC (const char *, num_cp_abis + 1);
 369       for (i = 0; i < num_cp_abis; ++i)
 370         cp_abi_names[i] = cp_abis[i]->shortname;
 371       cp_abi_names[i] = NULL;
 372     }
 373
 374   complete_on_enum (tracker, cp_abi_names, text, word);
 375 }
 376
 377 /* Show the currently selected C++ ABI.  */
 378
 379 static void
 380 show_cp_abi_cmd (const char *args, int from_tty)
 381 {
 382   struct ui_out *uiout = current_uiout;
 383
 384   uiout->text ("The currently selected C++ ABI is \"");
 385
 386   uiout->field_string ("cp-abi", current_cp_abi.shortname);
 387   uiout->text ("\" (");
 388   uiout->field_string ("longname", current_cp_abi.longname);
 389   uiout->text (").\n");
 390 }
 391
 392 void _initialize_cp_abi ();
 393 void
 394 _initialize_cp_abi ()
 395 {
 396   struct cmd_list_element *c;
 397
 398   register_cp_abi (&auto_cp_abi);
 399   switch_to_cp_abi ("auto");
 400
 401   c = add_cmd ("cp-abi", class_obscure, set_cp_abi_cmd, _("\
 402 Set the ABI used for inspecting C++ objects.\n\
 403 \"set cp-abi\" with no arguments will list the available ABIs."),
 404                &setlist);
 405   set_cmd_completer (c, cp_abi_completer);
 406
 407   add_cmd ("cp-abi", class_obscure, show_cp_abi_cmd,
 408            _("Show the ABI used for inspecting C++ objects."),
 409            &showlist);
 410 }