gdb/cp-abi.c

   1 /* Generic code for supporting multiple C++ ABI's
   2
   3    Copyright (C) 2001-2019 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_RETURN_MASK_ERROR &ex)
  83     {
  84       if (ex.error != NOT_AVAILABLE_ERROR)
  85         throw_exception (ex);
  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     return NULL;
 114   try
 115     {
 116       ret = (*current_cp_abi.rtti_type) (v, full, top, using_enc);
 117     }
 118   catch (const gdb_exception_RETURN_MASK_ERROR &e)
 119     {
 120       return NULL;
 121     }
 122
 123   return ret;
 124 }
 125
 126 void
 127 cplus_print_method_ptr (const gdb_byte *contents,
 128                         struct type *type,
 129                         struct ui_file *stream)
 130 {
 131   if (current_cp_abi.print_method_ptr == NULL)
 132     error (_("GDB does not support pointers to methods on this target"));
 133   (*current_cp_abi.print_method_ptr) (contents, type, stream);
 134 }
 135
 136 int
 137 cplus_method_ptr_size (struct type *to_type)
 138 {
 139   if (current_cp_abi.method_ptr_size == NULL)
 140     error (_("GDB does not support pointers to methods on this target"));
 141   return (*current_cp_abi.method_ptr_size) (to_type);
 142 }
 143
 144 void
 145 cplus_make_method_ptr (struct type *type, gdb_byte *contents,
 146                        CORE_ADDR value, int is_virtual)
 147 {
 148   if (current_cp_abi.make_method_ptr == NULL)
 149     error (_("GDB does not support pointers to methods on this target"));
 150   (*current_cp_abi.make_method_ptr) (type, contents, value, is_virtual);
 151 }
 152
 153 CORE_ADDR
 154 cplus_skip_trampoline (struct frame_info *frame,
 155                        CORE_ADDR stop_pc)
 156 {
 157   if (current_cp_abi.skip_trampoline == NULL)
 158     return 0;
 159   return (*current_cp_abi.skip_trampoline) (frame, stop_pc);
 160 }
 161
 162 struct value *
 163 cplus_method_ptr_to_value (struct value **this_p,
 164                            struct value *method_ptr)
 165 {
 166   if (current_cp_abi.method_ptr_to_value == NULL)
 167     error (_("GDB does not support pointers to methods on this target"));
 168   return (*current_cp_abi.method_ptr_to_value) (this_p, method_ptr);
 169 }
 170
 171 /* See cp-abi.h.  */
 172
 173 void
 174 cplus_print_vtable (struct value *value)
 175 {
 176   if (current_cp_abi.print_vtable == NULL)
 177     error (_("GDB cannot print the vtable on this target"));
 178   (*current_cp_abi.print_vtable) (value);
 179 }
 180
 181 /* See cp-abi.h.  */
 182
 183 struct value *
 184 cplus_typeid (struct value *value)
 185 {
 186   if (current_cp_abi.get_typeid == NULL)
 187     error (_("GDB cannot find the typeid on this target"));
 188   return (*current_cp_abi.get_typeid) (value);
 189 }
 190
 191 /* See cp-abi.h.  */
 192
 193 struct type *
 194 cplus_typeid_type (struct gdbarch *gdbarch)
 195 {
 196   if (current_cp_abi.get_typeid_type == NULL)
 197     error (_("GDB cannot find the type for 'typeid' on this target"));
 198   return (*current_cp_abi.get_typeid_type) (gdbarch);
 199 }
 200
 201 /* See cp-abi.h.  */
 202
 203 struct type *
 204 cplus_type_from_type_info (struct value *value)
 205 {
 206   if (current_cp_abi.get_type_from_type_info == NULL)
 207     error (_("GDB cannot find the type from a std::type_info on this target"));
 208   return (*current_cp_abi.get_type_from_type_info) (value);
 209 }
 210
 211 /* See cp-abi.h.  */
 212
 213 std::string
 214 cplus_typename_from_type_info (struct value *value)
 215 {
 216   if (current_cp_abi.get_typename_from_type_info == NULL)
 217     error (_("GDB cannot find the type name "
 218              "from a std::type_info on this target"));
 219   return (*current_cp_abi.get_typename_from_type_info) (value);
 220 }
 221
 222 int
 223 cp_pass_by_reference (struct type *type)
 224 {
 225   if ((current_cp_abi.pass_by_reference) == NULL)
 226     return 0;
 227   return (*current_cp_abi.pass_by_reference) (type);
 228 }
 229
 230 /* Set the current C++ ABI to SHORT_NAME.  */
 231
 232 static int
 233 switch_to_cp_abi (const char *short_name)
 234 {
 235   struct cp_abi_ops *abi;
 236
 237   abi = find_cp_abi (short_name);
 238   if (abi == NULL)
 239     return 0;
 240
 241   current_cp_abi = *abi;
 242   return 1;
 243 }
 244
 245 /* Add ABI to the list of supported C++ ABI's.  */
 246
 247 int
 248 register_cp_abi (struct cp_abi_ops *abi)
 249 {
 250   if (num_cp_abis == CP_ABI_MAX)
 251     internal_error (__FILE__, __LINE__,
 252                     _("Too many C++ ABIs, please increase "
 253                       "CP_ABI_MAX in cp-abi.c"));
 254
 255   cp_abis[num_cp_abis++] = abi;
 256
 257   return 1;
 258 }
 259
 260 /* Set the ABI to use in "auto" mode to SHORT_NAME.  */
 261
 262 void
 263 set_cp_abi_as_auto_default (const char *short_name)
 264 {
 265   char *new_longname, *new_doc;
 266   struct cp_abi_ops *abi = find_cp_abi (short_name);
 267
 268   if (abi == NULL)
 269     internal_error (__FILE__, __LINE__,
 270                     _("Cannot find C++ ABI \"%s\" to set it as auto default."),
 271                     short_name);
 272
 273   if (auto_cp_abi.longname != NULL)
 274     xfree ((char *) auto_cp_abi.longname);
 275   if (auto_cp_abi.doc != NULL)
 276     xfree ((char *) auto_cp_abi.doc);
 277
 278   auto_cp_abi = *abi;
 279
 280   auto_cp_abi.shortname = "auto";
 281   new_longname = xstrprintf ("currently \"%s\"", abi->shortname);
 282   auto_cp_abi.longname = new_longname;
 283
 284   new_doc = xstrprintf ("Automatically selected; currently \"%s\"",
 285              abi->shortname);
 286   auto_cp_abi.doc = new_doc;
 287
 288   /* Since we copy the current ABI into current_cp_abi instead of
 289      using a pointer, if auto is currently the default, we need to
 290      reset it.  */
 291   if (strcmp (current_cp_abi.shortname, "auto") == 0)
 292     switch_to_cp_abi ("auto");
 293 }
 294
 295 /* Return the ABI operations associated with SHORT_NAME.  */
 296
 297 static struct cp_abi_ops *
 298 find_cp_abi (const char *short_name)
 299 {
 300   int i;
 301
 302   for (i = 0; i < num_cp_abis; i++)
 303     if (strcmp (cp_abis[i]->shortname, short_name) == 0)
 304       return cp_abis[i];
 305
 306   return NULL;
 307 }
 308
 309 /* Display the list of registered C++ ABIs.  */
 310
 311 static void
 312 list_cp_abis (int from_tty)
 313 {
 314   struct ui_out *uiout = current_uiout;
 315   int i;
 316
 317   uiout->text ("The available C++ ABIs are:\n");
 318   ui_out_emit_tuple tuple_emitter (uiout, "cp-abi-list");
 319   for (i = 0; i < num_cp_abis; i++)
 320     {
 321       char pad[14];
 322       int padcount;
 323
 324       uiout->text ("  ");
 325       uiout->field_string ("cp-abi", cp_abis[i]->shortname);
 326
 327       padcount = 16 - 2 - strlen (cp_abis[i]->shortname);
 328       pad[padcount] = 0;
 329       while (padcount > 0)
 330         pad[--padcount] = ' ';
 331       uiout->text (pad);
 332
 333       uiout->field_string ("doc", cp_abis[i]->doc);
 334       uiout->text ("\n");
 335     }
 336 }
 337
 338 /* Set the current C++ ABI, or display the list of options if no
 339    argument is given.  */
 340
 341 static void
 342 set_cp_abi_cmd (const char *args, int from_tty)
 343 {
 344   if (args == NULL)
 345     {
 346       list_cp_abis (from_tty);
 347       return;
 348     }
 349
 350   if (!switch_to_cp_abi (args))
 351     error (_("Could not find \"%s\" in ABI list"), args);
 352 }
 353
 354 /* A completion function for "set cp-abi".  */
 355
 356 static void
 357 cp_abi_completer (struct cmd_list_element *ignore,
 358                   completion_tracker &tracker,
 359                   const char *text, const char *word)
 360 {
 361   static const char **cp_abi_names;
 362
 363   if (cp_abi_names == NULL)
 364     {
 365       int i;
 366
 367       cp_abi_names = XNEWVEC (const char *, num_cp_abis + 1);
 368       for (i = 0; i < num_cp_abis; ++i)
 369         cp_abi_names[i] = cp_abis[i]->shortname;
 370       cp_abi_names[i] = NULL;
 371     }
 372
 373   complete_on_enum (tracker, cp_abi_names, text, word);
 374 }
 375
 376 /* Show the currently selected C++ ABI.  */
 377
 378 static void
 379 show_cp_abi_cmd (const char *args, int from_tty)
 380 {
 381   struct ui_out *uiout = current_uiout;
 382
 383   uiout->text ("The currently selected C++ ABI is \"");
 384
 385   uiout->field_string ("cp-abi", current_cp_abi.shortname);
 386   uiout->text ("\" (");
 387   uiout->field_string ("longname", current_cp_abi.longname);
 388   uiout->text (").\n");
 389 }
 390
 391 void
 392 _initialize_cp_abi (void)
 393 {
 394   struct cmd_list_element *c;
 395
 396   register_cp_abi (&auto_cp_abi);
 397   switch_to_cp_abi ("auto");
 398
 399   c = add_cmd ("cp-abi", class_obscure, set_cp_abi_cmd, _("\
 400 Set the ABI used for inspecting C++ objects.\n\
 401 \"set cp-abi\" with no arguments will list the available ABIs."),
 402                &setlist);
 403   set_cmd_completer (c, cp_abi_completer);
 404
 405   add_cmd ("cp-abi", class_obscure, show_cp_abi_cmd,
 406            _("Show the ABI used for inspecting C++ objects."),
 407            &showlist);
 408 }