]> git.ipfire.org Git - thirdparty/binutils-gdb.git/blob - gdb/typeprint.c
Stop assuming no-debug-info functions return int
[thirdparty/binutils-gdb.git] / gdb / typeprint.c
1 /* Language independent support for printing types for GDB, the GNU debugger.
2
3 Copyright (C) 1986-2017 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 "gdb_obstack.h"
22 #include "bfd.h" /* Binary File Description */
23 #include "symtab.h"
24 #include "gdbtypes.h"
25 #include "expression.h"
26 #include "value.h"
27 #include "gdbcore.h"
28 #include "command.h"
29 #include "gdbcmd.h"
30 #include "target.h"
31 #include "language.h"
32 #include "cp-abi.h"
33 #include "typeprint.h"
34 #include "valprint.h"
35 #include <ctype.h>
36 #include "cli/cli-utils.h"
37 #include "extension.h"
38 #include "completer.h"
39
40 extern void _initialize_typeprint (void);
41
42 static void ptype_command (char *, int);
43
44 static void whatis_command (char *, int);
45
46 static void whatis_exp (char *, int);
47
48 const struct type_print_options type_print_raw_options =
49 {
50 1, /* raw */
51 1, /* print_methods */
52 1, /* print_typedefs */
53 NULL, /* local_typedefs */
54 NULL, /* global_table */
55 NULL /* global_printers */
56 };
57
58 /* The default flags for 'ptype' and 'whatis'. */
59
60 static struct type_print_options default_ptype_flags =
61 {
62 0, /* raw */
63 1, /* print_methods */
64 1, /* print_typedefs */
65 NULL, /* local_typedefs */
66 NULL, /* global_table */
67 NULL /* global_printers */
68 };
69
70 \f
71
72 /* A hash table holding typedef_field objects. This is more
73 complicated than an ordinary hash because it must also track the
74 lifetime of some -- but not all -- of the contained objects. */
75
76 struct typedef_hash_table
77 {
78 /* The actual hash table. */
79 htab_t table;
80
81 /* Storage for typedef_field objects that must be synthesized. */
82 struct obstack storage;
83 };
84
85 /* A hash function for a typedef_field. */
86
87 static hashval_t
88 hash_typedef_field (const void *p)
89 {
90 const struct typedef_field *tf = (const struct typedef_field *) p;
91 struct type *t = check_typedef (tf->type);
92
93 return htab_hash_string (TYPE_SAFE_NAME (t));
94 }
95
96 /* An equality function for a typedef field. */
97
98 static int
99 eq_typedef_field (const void *a, const void *b)
100 {
101 const struct typedef_field *tfa = (const struct typedef_field *) a;
102 const struct typedef_field *tfb = (const struct typedef_field *) b;
103
104 return types_equal (tfa->type, tfb->type);
105 }
106
107 /* Add typedefs from T to the hash table TABLE. */
108
109 void
110 recursively_update_typedef_hash (struct typedef_hash_table *table,
111 struct type *t)
112 {
113 int i;
114
115 if (table == NULL)
116 return;
117
118 for (i = 0; i < TYPE_TYPEDEF_FIELD_COUNT (t); ++i)
119 {
120 struct typedef_field *tdef = &TYPE_TYPEDEF_FIELD (t, i);
121 void **slot;
122
123 slot = htab_find_slot (table->table, tdef, INSERT);
124 /* Only add a given typedef name once. Really this shouldn't
125 happen; but it is safe enough to do the updates breadth-first
126 and thus use the most specific typedef. */
127 if (*slot == NULL)
128 *slot = tdef;
129 }
130
131 /* Recurse into superclasses. */
132 for (i = 0; i < TYPE_N_BASECLASSES (t); ++i)
133 recursively_update_typedef_hash (table, TYPE_BASECLASS (t, i));
134 }
135
136 /* Add template parameters from T to the typedef hash TABLE. */
137
138 void
139 add_template_parameters (struct typedef_hash_table *table, struct type *t)
140 {
141 int i;
142
143 if (table == NULL)
144 return;
145
146 for (i = 0; i < TYPE_N_TEMPLATE_ARGUMENTS (t); ++i)
147 {
148 struct typedef_field *tf;
149 void **slot;
150
151 /* We only want type-valued template parameters in the hash. */
152 if (SYMBOL_CLASS (TYPE_TEMPLATE_ARGUMENT (t, i)) != LOC_TYPEDEF)
153 continue;
154
155 tf = XOBNEW (&table->storage, struct typedef_field);
156 tf->name = SYMBOL_LINKAGE_NAME (TYPE_TEMPLATE_ARGUMENT (t, i));
157 tf->type = SYMBOL_TYPE (TYPE_TEMPLATE_ARGUMENT (t, i));
158
159 slot = htab_find_slot (table->table, tf, INSERT);
160 if (*slot == NULL)
161 *slot = tf;
162 }
163 }
164
165 /* Create a new typedef-lookup hash table. */
166
167 struct typedef_hash_table *
168 create_typedef_hash (void)
169 {
170 struct typedef_hash_table *result;
171
172 result = XNEW (struct typedef_hash_table);
173 result->table = htab_create_alloc (10, hash_typedef_field, eq_typedef_field,
174 NULL, xcalloc, xfree);
175 obstack_init (&result->storage);
176
177 return result;
178 }
179
180 /* Free a typedef field table. */
181
182 void
183 free_typedef_hash (struct typedef_hash_table *table)
184 {
185 if (table != NULL)
186 {
187 htab_delete (table->table);
188 obstack_free (&table->storage, NULL);
189 xfree (table);
190 }
191 }
192
193 /* A cleanup for freeing a typedef_hash_table. */
194
195 static void
196 do_free_typedef_hash (void *arg)
197 {
198 free_typedef_hash ((struct typedef_hash_table *) arg);
199 }
200
201 /* Return a new cleanup that frees TABLE. */
202
203 struct cleanup *
204 make_cleanup_free_typedef_hash (struct typedef_hash_table *table)
205 {
206 return make_cleanup (do_free_typedef_hash, table);
207 }
208
209 /* Helper function for copy_typedef_hash. */
210
211 static int
212 copy_typedef_hash_element (void **slot, void *nt)
213 {
214 htab_t new_table = (htab_t) nt;
215 void **new_slot;
216
217 new_slot = htab_find_slot (new_table, *slot, INSERT);
218 if (*new_slot == NULL)
219 *new_slot = *slot;
220
221 return 1;
222 }
223
224 /* Copy a typedef hash. */
225
226 struct typedef_hash_table *
227 copy_typedef_hash (struct typedef_hash_table *table)
228 {
229 struct typedef_hash_table *result;
230
231 if (table == NULL)
232 return NULL;
233
234 result = create_typedef_hash ();
235 htab_traverse_noresize (table->table, copy_typedef_hash_element,
236 result->table);
237 return result;
238 }
239
240 /* A cleanup to free the global typedef hash. */
241
242 static void
243 do_free_global_table (void *arg)
244 {
245 struct type_print_options *flags = (struct type_print_options *) arg;
246
247 free_typedef_hash (flags->global_typedefs);
248 free_ext_lang_type_printers (flags->global_printers);
249 }
250
251 /* Create the global typedef hash. */
252
253 static struct cleanup *
254 create_global_typedef_table (struct type_print_options *flags)
255 {
256 gdb_assert (flags->global_typedefs == NULL && flags->global_printers == NULL);
257 flags->global_typedefs = create_typedef_hash ();
258 flags->global_printers = start_ext_lang_type_printers ();
259 return make_cleanup (do_free_global_table, flags);
260 }
261
262 /* Look up the type T in the global typedef hash. If it is found,
263 return the typedef name. If it is not found, apply the
264 type-printers, if any, given by start_script_type_printers and return the
265 result. A NULL return means that the name was not found. */
266
267 static const char *
268 find_global_typedef (const struct type_print_options *flags,
269 struct type *t)
270 {
271 char *applied;
272 void **slot;
273 struct typedef_field tf, *new_tf;
274
275 if (flags->global_typedefs == NULL)
276 return NULL;
277
278 tf.name = NULL;
279 tf.type = t;
280
281 slot = htab_find_slot (flags->global_typedefs->table, &tf, INSERT);
282 if (*slot != NULL)
283 {
284 new_tf = (struct typedef_field *) *slot;
285 return new_tf->name;
286 }
287
288 /* Put an entry into the hash table now, in case
289 apply_ext_lang_type_printers recurses. */
290 new_tf = XOBNEW (&flags->global_typedefs->storage, struct typedef_field);
291 new_tf->name = NULL;
292 new_tf->type = t;
293
294 *slot = new_tf;
295
296 applied = apply_ext_lang_type_printers (flags->global_printers, t);
297
298 if (applied != NULL)
299 {
300 new_tf->name
301 = (const char *) obstack_copy0 (&flags->global_typedefs->storage,
302 applied, strlen (applied));
303 xfree (applied);
304 }
305
306 return new_tf->name;
307 }
308
309 /* Look up the type T in the typedef hash table in with FLAGS. If T
310 is in the table, return its short (class-relative) typedef name.
311 Otherwise return NULL. If the table is NULL, this always returns
312 NULL. */
313
314 const char *
315 find_typedef_in_hash (const struct type_print_options *flags, struct type *t)
316 {
317 if (flags->local_typedefs != NULL)
318 {
319 struct typedef_field tf, *found;
320
321 tf.name = NULL;
322 tf.type = t;
323 found = (struct typedef_field *) htab_find (flags->local_typedefs->table,
324 &tf);
325
326 if (found != NULL)
327 return found->name;
328 }
329
330 return find_global_typedef (flags, t);
331 }
332
333 \f
334
335 /* Print a description of a type in the format of a
336 typedef for the current language.
337 NEW is the new name for a type TYPE. */
338
339 void
340 typedef_print (struct type *type, struct symbol *newobj, struct ui_file *stream)
341 {
342 LA_PRINT_TYPEDEF (type, newobj, stream);
343 }
344
345 /* The default way to print a typedef. */
346
347 void
348 default_print_typedef (struct type *type, struct symbol *new_symbol,
349 struct ui_file *stream)
350 {
351 error (_("Language not supported."));
352 }
353
354 /* Print a description of a type TYPE in the form of a declaration of a
355 variable named VARSTRING. (VARSTRING is demangled if necessary.)
356 Output goes to STREAM (via stdio).
357 If SHOW is positive, we show the contents of the outermost level
358 of structure even if there is a type name that could be used instead.
359 If SHOW is negative, we never show the details of elements' types. */
360
361 void
362 type_print (struct type *type, const char *varstring, struct ui_file *stream,
363 int show)
364 {
365 LA_PRINT_TYPE (type, varstring, stream, show, 0, &default_ptype_flags);
366 }
367
368 /* Print TYPE to a string, returning it. The caller is responsible for
369 freeing the string. */
370
371 std::string
372 type_to_string (struct type *type)
373 {
374 TRY
375 {
376 string_file stb;
377
378 type_print (type, "", &stb, -1);
379 return std::move (stb.string ());
380 }
381 CATCH (except, RETURN_MASK_ALL)
382 {
383 }
384 END_CATCH
385
386 return {};
387 }
388
389 /* See typeprint.h. */
390
391 void
392 type_print_unknown_return_type (struct ui_file *stream)
393 {
394 fprintf_filtered (stream, _("<unknown return type>"));
395 }
396
397 /* Print type of EXP, or last thing in value history if EXP == NULL.
398 show is passed to type_print. */
399
400 static void
401 whatis_exp (char *exp, int show)
402 {
403 struct value *val;
404 struct cleanup *old_chain;
405 struct type *real_type = NULL;
406 struct type *type;
407 int full = 0;
408 LONGEST top = -1;
409 int using_enc = 0;
410 struct value_print_options opts;
411 struct type_print_options flags = default_ptype_flags;
412
413 old_chain = make_cleanup (null_cleanup, NULL);
414
415 if (exp)
416 {
417 if (*exp == '/')
418 {
419 int seen_one = 0;
420
421 for (++exp; *exp && !isspace (*exp); ++exp)
422 {
423 switch (*exp)
424 {
425 case 'r':
426 flags.raw = 1;
427 break;
428 case 'm':
429 flags.print_methods = 0;
430 break;
431 case 'M':
432 flags.print_methods = 1;
433 break;
434 case 't':
435 flags.print_typedefs = 0;
436 break;
437 case 'T':
438 flags.print_typedefs = 1;
439 break;
440 default:
441 error (_("unrecognized flag '%c'"), *exp);
442 }
443 seen_one = 1;
444 }
445
446 if (!*exp && !seen_one)
447 error (_("flag expected"));
448 if (!isspace (*exp))
449 error (_("expected space after format"));
450 exp = skip_spaces (exp);
451 }
452
453 expression_up expr = parse_expression (exp);
454
455 /* The behavior of "whatis" depends on whether the user
456 expression names a type directly, or a language expression
457 (including variable names). If the former, then "whatis"
458 strips one level of typedefs, only. If an expression,
459 "whatis" prints the type of the expression without stripping
460 any typedef level. "ptype" always strips all levels of
461 typedefs. */
462 if (show == -1 && expr->elts[0].opcode == OP_TYPE)
463 {
464 /* The user expression names a type directly. */
465 type = expr->elts[1].type;
466
467 /* If this is a typedef, then find its immediate target.
468 Use check_typedef to resolve stubs, but ignore its result
469 because we do not want to dig past all typedefs. */
470 check_typedef (type);
471 if (TYPE_CODE (type) == TYPE_CODE_TYPEDEF)
472 type = TYPE_TARGET_TYPE (type);
473 }
474 else
475 {
476 /* The user expression names a type indirectly by naming an
477 object or expression of that type. Find that
478 indirectly-named type. */
479 val = evaluate_type (expr.get ());
480 type = value_type (val);
481 }
482 }
483 else
484 {
485 val = access_value_history (0);
486 type = value_type (val);
487 }
488
489 get_user_print_options (&opts);
490 if (opts.objectprint)
491 {
492 if (((TYPE_CODE (type) == TYPE_CODE_PTR) || TYPE_IS_REFERENCE (type))
493 && (TYPE_CODE (TYPE_TARGET_TYPE (type)) == TYPE_CODE_STRUCT))
494 real_type = value_rtti_indirect_type (val, &full, &top, &using_enc);
495 else if (TYPE_CODE (type) == TYPE_CODE_STRUCT)
496 real_type = value_rtti_type (val, &full, &top, &using_enc);
497 }
498
499 printf_filtered ("type = ");
500
501 if (!flags.raw)
502 create_global_typedef_table (&flags);
503
504 if (real_type)
505 {
506 printf_filtered ("/* real type = ");
507 type_print (real_type, "", gdb_stdout, -1);
508 if (! full)
509 printf_filtered (" (incomplete object)");
510 printf_filtered (" */\n");
511 }
512
513 LA_PRINT_TYPE (type, "", gdb_stdout, show, 0, &flags);
514 printf_filtered ("\n");
515
516 do_cleanups (old_chain);
517 }
518
519 static void
520 whatis_command (char *exp, int from_tty)
521 {
522 /* Most of the time users do not want to see all the fields
523 in a structure. If they do they can use the "ptype" command.
524 Hence the "-1" below. */
525 whatis_exp (exp, -1);
526 }
527
528 /* TYPENAME is either the name of a type, or an expression. */
529
530 static void
531 ptype_command (char *type_name, int from_tty)
532 {
533 whatis_exp (type_name, 1);
534 }
535
536 /* Print integral scalar data VAL, of type TYPE, onto stdio stream STREAM.
537 Used to print data from type structures in a specified type. For example,
538 array bounds may be characters or booleans in some languages, and this
539 allows the ranges to be printed in their "natural" form rather than as
540 decimal integer values.
541
542 FIXME: This is here simply because only the type printing routines
543 currently use it, and it wasn't clear if it really belonged somewhere
544 else (like printcmd.c). There are a lot of other gdb routines that do
545 something similar, but they are generally concerned with printing values
546 that come from the inferior in target byte order and target size. */
547
548 void
549 print_type_scalar (struct type *type, LONGEST val, struct ui_file *stream)
550 {
551 unsigned int i;
552 unsigned len;
553
554 type = check_typedef (type);
555
556 switch (TYPE_CODE (type))
557 {
558
559 case TYPE_CODE_ENUM:
560 len = TYPE_NFIELDS (type);
561 for (i = 0; i < len; i++)
562 {
563 if (TYPE_FIELD_ENUMVAL (type, i) == val)
564 {
565 break;
566 }
567 }
568 if (i < len)
569 {
570 fputs_filtered (TYPE_FIELD_NAME (type, i), stream);
571 }
572 else
573 {
574 print_longest (stream, 'd', 0, val);
575 }
576 break;
577
578 case TYPE_CODE_INT:
579 print_longest (stream, TYPE_UNSIGNED (type) ? 'u' : 'd', 0, val);
580 break;
581
582 case TYPE_CODE_CHAR:
583 LA_PRINT_CHAR ((unsigned char) val, type, stream);
584 break;
585
586 case TYPE_CODE_BOOL:
587 fprintf_filtered (stream, val ? "TRUE" : "FALSE");
588 break;
589
590 case TYPE_CODE_RANGE:
591 print_type_scalar (TYPE_TARGET_TYPE (type), val, stream);
592 return;
593
594 case TYPE_CODE_UNDEF:
595 case TYPE_CODE_PTR:
596 case TYPE_CODE_ARRAY:
597 case TYPE_CODE_STRUCT:
598 case TYPE_CODE_UNION:
599 case TYPE_CODE_FUNC:
600 case TYPE_CODE_FLT:
601 case TYPE_CODE_VOID:
602 case TYPE_CODE_SET:
603 case TYPE_CODE_STRING:
604 case TYPE_CODE_ERROR:
605 case TYPE_CODE_MEMBERPTR:
606 case TYPE_CODE_METHODPTR:
607 case TYPE_CODE_METHOD:
608 case TYPE_CODE_REF:
609 case TYPE_CODE_RVALUE_REF:
610 case TYPE_CODE_NAMESPACE:
611 error (_("internal error: unhandled type in print_type_scalar"));
612 break;
613
614 default:
615 error (_("Invalid type code in symbol table."));
616 }
617 gdb_flush (stream);
618 }
619
620 /* Dump details of a type specified either directly or indirectly.
621 Uses the same sort of type lookup mechanism as ptype_command()
622 and whatis_command(). */
623
624 void
625 maintenance_print_type (char *type_name, int from_tty)
626 {
627 struct value *val;
628 struct type *type;
629
630 if (type_name != NULL)
631 {
632 expression_up expr = parse_expression (type_name);
633 if (expr->elts[0].opcode == OP_TYPE)
634 {
635 /* The user expression names a type directly, just use that type. */
636 type = expr->elts[1].type;
637 }
638 else
639 {
640 /* The user expression may name a type indirectly by naming an
641 object of that type. Find that indirectly named type. */
642 val = evaluate_type (expr.get ());
643 type = value_type (val);
644 }
645 if (type != NULL)
646 {
647 recursive_dump_type (type, 0);
648 }
649 }
650 }
651 \f
652
653 struct cmd_list_element *setprinttypelist;
654
655 struct cmd_list_element *showprinttypelist;
656
657 static void
658 set_print_type (char *arg, int from_tty)
659 {
660 printf_unfiltered (
661 "\"set print type\" must be followed by the name of a subcommand.\n");
662 help_list (setprintlist, "set print type ", all_commands, gdb_stdout);
663 }
664
665 static void
666 show_print_type (char *args, int from_tty)
667 {
668 cmd_show_list (showprinttypelist, from_tty, "");
669 }
670
671 static int print_methods = 1;
672
673 static void
674 set_print_type_methods (char *args, int from_tty, struct cmd_list_element *c)
675 {
676 default_ptype_flags.print_methods = print_methods;
677 }
678
679 static void
680 show_print_type_methods (struct ui_file *file, int from_tty,
681 struct cmd_list_element *c, const char *value)
682 {
683 fprintf_filtered (file, _("Printing of methods defined in a class in %s\n"),
684 value);
685 }
686
687 static int print_typedefs = 1;
688
689 static void
690 set_print_type_typedefs (char *args, int from_tty, struct cmd_list_element *c)
691 {
692 default_ptype_flags.print_typedefs = print_typedefs;
693 }
694
695 static void
696 show_print_type_typedefs (struct ui_file *file, int from_tty,
697 struct cmd_list_element *c, const char *value)
698 {
699 fprintf_filtered (file, _("Printing of typedefs defined in a class in %s\n"),
700 value);
701 }
702
703 void
704 _initialize_typeprint (void)
705 {
706 struct cmd_list_element *c;
707
708 c = add_com ("ptype", class_vars, ptype_command, _("\
709 Print definition of type TYPE.\n\
710 Usage: ptype[/FLAGS] TYPE | EXPRESSION\n\
711 Argument may be any type (for example a type name defined by typedef,\n\
712 or \"struct STRUCT-TAG\" or \"class CLASS-NAME\" or \"union UNION-TAG\"\n\
713 or \"enum ENUM-TAG\") or an expression.\n\
714 The selected stack frame's lexical context is used to look up the name.\n\
715 Contrary to \"whatis\", \"ptype\" always unrolls any typedefs.\n\
716 \n\
717 Available FLAGS are:\n\
718 /r print in \"raw\" form; do not substitute typedefs\n\
719 /m do not print methods defined in a class\n\
720 /M print methods defined in a class\n\
721 /t do not print typedefs defined in a class\n\
722 /T print typedefs defined in a class"));
723 set_cmd_completer (c, expression_completer);
724
725 c = add_com ("whatis", class_vars, whatis_command,
726 _("Print data type of expression EXP.\n\
727 Only one level of typedefs is unrolled. See also \"ptype\"."));
728 set_cmd_completer (c, expression_completer);
729
730 add_prefix_cmd ("type", no_class, show_print_type,
731 _("Generic command for showing type-printing settings."),
732 &showprinttypelist, "show print type ", 0, &showprintlist);
733 add_prefix_cmd ("type", no_class, set_print_type,
734 _("Generic command for setting how types print."),
735 &setprinttypelist, "show print type ", 0, &setprintlist);
736
737 add_setshow_boolean_cmd ("methods", no_class, &print_methods,
738 _("\
739 Set printing of methods defined in classes."), _("\
740 Show printing of methods defined in classes."), NULL,
741 set_print_type_methods,
742 show_print_type_methods,
743 &setprinttypelist, &showprinttypelist);
744 add_setshow_boolean_cmd ("typedefs", no_class, &print_typedefs,
745 _("\
746 Set printing of typedefs defined in classes."), _("\
747 Show printing of typedefs defined in classes."), NULL,
748 set_print_type_typedefs,
749 show_print_type_typedefs,
750 &setprinttypelist, &showprinttypelist);
751 }
752
753 /* Print <not allocated> status to stream STREAM. */
754
755 void
756 val_print_not_allocated (struct ui_file *stream)
757 {
758 fprintf_filtered (stream, _("<not allocated>"));
759 }
760
761 /* Print <not associated> status to stream STREAM. */
762
763 void
764 val_print_not_associated (struct ui_file *stream)
765 {
766 fprintf_filtered (stream, _("<not associated>"));
767 }