gdb/cp-abi.c

   1 /* Generic code for supporting multiple C++ ABI's
   2
   3    Copyright (C) 2001-2017 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 (ex, RETURN_MASK_ERROR)
  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   END_CATCH
  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     return NULL;
 115   TRY
 116     {
 117       ret = (*current_cp_abi.rtti_type) (v, full, top, using_enc);
 118     }
 119   CATCH (e, RETURN_MASK_ERROR)
 120     {
 121       return NULL;
 122     }
 123   END_CATCH
 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 (struct frame_info *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 int
 225 cp_pass_by_reference (struct type *type)
 226 {
 227   if ((current_cp_abi.pass_by_reference) == NULL)
 228     return 0;
 229   return (*current_cp_abi.pass_by_reference) (type);
 230 }
 231
 232 /* Set the current C++ ABI to SHORT_NAME.  */
 233
 234 static int
 235 switch_to_cp_abi (const char *short_name)
 236 {
 237   struct cp_abi_ops *abi;
 238
 239   abi = find_cp_abi (short_name);
 240   if (abi == NULL)
 241     return 0;
 242
 243   current_cp_abi = *abi;
 244   return 1;
 245 }
 246
 247 /* Add ABI to the list of supported C++ ABI's.  */
 248
 249 int
 250 register_cp_abi (struct cp_abi_ops *abi)
 251 {
 252   if (num_cp_abis == CP_ABI_MAX)
 253     internal_error (__FILE__, __LINE__,
 254                     _("Too many C++ ABIs, please increase "
 255                       "CP_ABI_MAX in cp-abi.c"));
 256
 257   cp_abis[num_cp_abis++] = abi;
 258
 259   return 1;
 260 }
 261
 262 /* Set the ABI to use in "auto" mode to SHORT_NAME.  */
 263
 264 void
 265 set_cp_abi_as_auto_default (const char *short_name)
 266 {
 267   char *new_longname, *new_doc;
 268   struct cp_abi_ops *abi = find_cp_abi (short_name);
 269
 270   if (abi == NULL)
 271     internal_error (__FILE__, __LINE__,
 272                     _("Cannot find C++ ABI \"%s\" to set it as auto default."),
 273                     short_name);
 274
 275   if (auto_cp_abi.longname != NULL)
 276     xfree ((char *) auto_cp_abi.longname);
 277   if (auto_cp_abi.doc != NULL)
 278     xfree ((char *) auto_cp_abi.doc);
 279
 280   auto_cp_abi = *abi;
 281
 282   auto_cp_abi.shortname = "auto";
 283   new_longname = xstrprintf ("currently \"%s\"", abi->shortname);
 284   auto_cp_abi.longname = new_longname;
 285
 286   new_doc = xstrprintf ("Automatically selected; currently \"%s\"",
 287              abi->shortname);
 288   auto_cp_abi.doc = new_doc;
 289
 290   /* Since we copy the current ABI into current_cp_abi instead of
 291      using a pointer, if auto is currently the default, we need to
 292      reset it.  */
 293   if (strcmp (current_cp_abi.shortname, "auto") == 0)
 294     switch_to_cp_abi ("auto");
 295 }
 296
 297 /* Return the ABI operations associated with SHORT_NAME.  */
 298
 299 static struct cp_abi_ops *
 300 find_cp_abi (const char *short_name)
 301 {
 302   int i;
 303
 304   for (i = 0; i < num_cp_abis; i++)
 305     if (strcmp (cp_abis[i]->shortname, short_name) == 0)
 306       return cp_abis[i];
 307
 308   return NULL;
 309 }
 310
 311 /* Display the list of registered C++ ABIs.  */
 312
 313 static void
 314 list_cp_abis (int from_tty)
 315 {
 316   struct ui_out *uiout = current_uiout;
 317   int i;
 318
 319   uiout->text ("The available C++ ABIs are:\n");
 320   ui_out_emit_tuple tuple_emitter (uiout, "cp-abi-list");
 321   for (i = 0; i < num_cp_abis; i++)
 322     {
 323       char pad[14];
 324       int padcount;
 325
 326       uiout->text ("  ");
 327       uiout->field_string ("cp-abi", cp_abis[i]->shortname);
 328
 329       padcount = 16 - 2 - strlen (cp_abis[i]->shortname);
 330       pad[padcount] = 0;
 331       while (padcount > 0)
 332         pad[--padcount] = ' ';
 333       uiout->text (pad);
 334
 335       uiout->field_string ("doc", cp_abis[i]->doc);
 336       uiout->text ("\n");
 337     }
 338 }
 339
 340 /* Set the current C++ ABI, or display the list of options if no
 341    argument is given.  */
 342
 343 static void
 344 set_cp_abi_cmd (char *args, int from_tty)
 345 {
 346   if (args == NULL)
 347     {
 348       list_cp_abis (from_tty);
 349       return;
 350     }
 351
 352   if (!switch_to_cp_abi (args))
 353     error (_("Could not find \"%s\" in ABI list"), args);
 354 }
 355
 356 /* A completion function for "set cp-abi".  */
 357
 358 static void
 359 cp_abi_completer (struct cmd_list_element *ignore,
 360                   completion_tracker &tracker,
 361                   const char *text, const char *word)
 362 {
 363   static const char **cp_abi_names;
 364
 365   if (cp_abi_names == NULL)
 366     {
 367       int i;
 368
 369       cp_abi_names = XNEWVEC (const char *, num_cp_abis + 1);
 370       for (i = 0; i < num_cp_abis; ++i)
 371         cp_abi_names[i] = cp_abis[i]->shortname;
 372       cp_abi_names[i] = NULL;
 373     }
 374
 375   complete_on_enum (tracker, cp_abi_names, text, word);
 376 }
 377
 378 /* Show the currently selected C++ ABI.  */
 379
 380 static void
 381 show_cp_abi_cmd (char *args, int from_tty)
 382 {
 383   struct ui_out *uiout = current_uiout;
 384
 385   uiout->text ("The currently selected C++ ABI is \"");
 386
 387   uiout->field_string ("cp-abi", current_cp_abi.shortname);
 388   uiout->text ("\" (");
 389   uiout->field_string ("longname", current_cp_abi.longname);
 390   uiout->text (").\n");
 391 }
 392
 393 extern initialize_file_ftype _initialize_cp_abi; /* -Wmissing-prototypes */
 394
 395 void
 396 _initialize_cp_abi (void)
 397 {
 398   struct cmd_list_element *c;
 399
 400   register_cp_abi (&auto_cp_abi);
 401   switch_to_cp_abi ("auto");
 402
 403   c = add_cmd ("cp-abi", class_obscure, set_cp_abi_cmd, _("\
 404 Set the ABI used for inspecting C++ objects.\n\
 405 \"set cp-abi\" with no arguments will list the available ABIs."),
 406                &setlist);
 407   set_cmd_completer (c, cp_abi_completer);
 408
 409   add_cmd ("cp-abi", class_obscure, show_cp_abi_cmd,
 410            _("Show the ABI used for inspecting C++ objects."),
 411            &showlist);
 412 }