1 /* Support for printing C values for GDB, the GNU debugger.
3 Copyright (C) 1986-2015 Free Software Foundation, Inc.
5 This file is part of GDB.
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.
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.
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/>. */
23 #include "expression.h"
33 /* A helper for c_textual_element_type. This checks the name of the
34 typedef. This is bogus but it isn't apparent that the compiler
35 provides us the help we may need. */
38 textual_name (const char *name)
40 return (!strcmp (name, "wchar_t")
41 || !strcmp (name, "char16_t")
42 || !strcmp (name, "char32_t"));
45 /* Apply a heuristic to decide whether an array of TYPE or a pointer
46 to TYPE should be printed as a textual string. Return non-zero if
47 it should, or zero if it should be treated as an array of integers
48 or pointer to integers. FORMAT is the current format letter, or 0
51 We guess that "char" is a character. Explicitly signed and
52 unsigned character types are also characters. Integer data from
53 vector types is not. The user can override this by using the /s
57 c_textual_element_type (struct type *type, char format)
59 struct type *true_type, *iter_type;
61 if (format != 0 && format != 's')
64 /* We also rely on this for its side effect of setting up all the
66 true_type = check_typedef (type);
68 /* TYPE_CODE_CHAR is always textual. */
69 if (TYPE_CODE (true_type) == TYPE_CODE_CHAR)
72 /* Any other character-like types must be integral. */
73 if (TYPE_CODE (true_type) != TYPE_CODE_INT)
76 /* We peel typedefs one by one, looking for a match. */
80 /* Check the name of the type. */
81 if (TYPE_NAME (iter_type) && textual_name (TYPE_NAME (iter_type)))
84 if (TYPE_CODE (iter_type) != TYPE_CODE_TYPEDEF)
87 /* Peel a single typedef. If the typedef doesn't have a target
88 type, we use check_typedef and hope the result is ok -- it
89 might be for C++, where wchar_t is a built-in type. */
90 if (TYPE_TARGET_TYPE (iter_type))
91 iter_type = TYPE_TARGET_TYPE (iter_type);
93 iter_type = check_typedef (iter_type);
98 /* Print this as a string if we can manage it. For now, no wide
100 if (TYPE_CODE (true_type) == TYPE_CODE_INT
101 && TYPE_LENGTH (true_type) == 1)
106 /* If a one-byte TYPE_CODE_INT is missing the not-a-character
107 flag, then we treat it as text; otherwise, we assume it's
108 being used as data. */
109 if (TYPE_CODE (true_type) == TYPE_CODE_INT
110 && TYPE_LENGTH (true_type) == 1
111 && !TYPE_NOTTEXT (true_type))
118 /* Decorations for C. */
120 static const struct generic_val_print_decorations c_decorations =
130 /* Print a pointer based on the type of its target.
132 Arguments to this functions are roughly the same as those in c_val_print.
133 A difference is that ADDRESS is the address to print, with embedded_offset
134 already added. UNRESOLVED_ELTTYPE and ELTTYPE represent the pointed type,
135 respectively before and after check_typedef. */
138 print_unpacked_pointer (struct type *type, struct type *elttype,
139 struct type *unresolved_elttype,
140 const gdb_byte *valaddr, int embedded_offset,
141 CORE_ADDR address, struct ui_file *stream, int recurse,
142 const struct value_print_options *options)
145 struct gdbarch *gdbarch = get_type_arch (type);
147 if (TYPE_CODE (elttype) == TYPE_CODE_FUNC)
149 /* Try to print what function it points to. */
150 print_function_pointer_address (options, gdbarch, address, stream);
154 if (options->symbol_print)
155 want_space = print_address_demangle (options, gdbarch, address, stream,
157 else if (options->addressprint)
159 fputs_filtered (paddress (gdbarch, address), stream);
163 /* For a pointer to a textual type, also print the string
164 pointed to, unless pointer is null. */
166 if (c_textual_element_type (unresolved_elttype, options->format)
170 fputs_filtered (" ", stream);
171 val_print_string (unresolved_elttype, NULL, address, -1, stream, options);
173 else if (cp_is_vtbl_member (type))
175 /* Print vtbl's nicely. */
176 CORE_ADDR vt_address = unpack_pointer (type, valaddr + embedded_offset);
177 struct bound_minimal_symbol msymbol =
178 lookup_minimal_symbol_by_pc (vt_address);
180 /* If 'symbol_print' is set, we did the work above. */
181 if (!options->symbol_print
182 && (msymbol.minsym != NULL)
183 && (vt_address == BMSYMBOL_VALUE_ADDRESS (msymbol)))
186 fputs_filtered (" ", stream);
187 fputs_filtered (" <", stream);
188 fputs_filtered (MSYMBOL_PRINT_NAME (msymbol.minsym), stream);
189 fputs_filtered (">", stream);
193 if (vt_address && options->vtblprint)
195 struct value *vt_val;
196 struct symbol *wsym = NULL;
198 struct block *block = NULL;
199 struct field_of_this_result is_this_fld;
202 fputs_filtered (" ", stream);
204 if (msymbol.minsym != NULL)
205 wsym = lookup_symbol (MSYMBOL_LINKAGE_NAME(msymbol.minsym), block,
206 VAR_DOMAIN, &is_this_fld).symbol;
210 wtype = SYMBOL_TYPE (wsym);
214 wtype = unresolved_elttype;
216 vt_val = value_at (wtype, vt_address);
217 common_val_print (vt_val, stream, recurse + 1, options,
219 if (options->prettyformat)
221 fprintf_filtered (stream, "\n");
222 print_spaces_filtered (2 + 2 * recurse, stream);
228 /* c_val_print helper for TYPE_CODE_ARRAY. */
231 c_val_print_array (struct type *type, const gdb_byte *valaddr,
232 int embedded_offset, CORE_ADDR address,
233 struct ui_file *stream, int recurse,
234 const struct value *original_value,
235 const struct value_print_options *options)
237 struct type *unresolved_elttype = TYPE_TARGET_TYPE (type);
238 struct type *elttype = check_typedef (unresolved_elttype);
239 struct gdbarch *arch = get_type_arch (type);
240 int unit_size = gdbarch_addressable_memory_unit_size (arch);
242 if (TYPE_LENGTH (type) > 0 && TYPE_LENGTH (unresolved_elttype) > 0)
244 LONGEST low_bound, high_bound;
246 struct gdbarch *gdbarch = get_type_arch (type);
247 enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
248 unsigned int i = 0; /* Number of characters printed. */
250 if (!get_array_bounds (type, &low_bound, &high_bound))
251 error (_("Could not determine the array high bound"));
253 eltlen = TYPE_LENGTH (elttype);
254 len = high_bound - low_bound + 1;
255 if (options->prettyformat_arrays)
257 print_spaces_filtered (2 + 2 * recurse, stream);
260 /* Print arrays of textual chars with a string syntax, as
261 long as the entire array is valid. */
262 if (c_textual_element_type (unresolved_elttype,
264 && value_bytes_available (original_value, embedded_offset,
266 && !value_bits_any_optimized_out (original_value,
267 TARGET_CHAR_BIT * embedded_offset,
268 TARGET_CHAR_BIT * TYPE_LENGTH (type)))
270 int force_ellipses = 0;
272 /* If requested, look for the first null char and only
273 print elements up to it. */
274 if (options->stop_print_at_null)
276 unsigned int temp_len;
280 && temp_len < options->print_max
281 && extract_unsigned_integer (valaddr
282 + embedded_offset * unit_size
284 eltlen, byte_order) != 0);
288 /* Force LA_PRINT_STRING to print ellipses if
289 we've printed the maximum characters and
290 the next character is not \000. */
291 if (temp_len == options->print_max && temp_len < len)
294 = extract_unsigned_integer (valaddr
295 + embedded_offset * unit_size
305 LA_PRINT_STRING (stream, unresolved_elttype,
306 valaddr + embedded_offset * unit_size, len,
307 NULL, force_ellipses, options);
312 fprintf_filtered (stream, "{");
313 /* If this is a virtual function table, print the 0th
314 entry specially, and the rest of the members
316 if (cp_is_vtbl_ptr_type (elttype))
319 fprintf_filtered (stream, _("%d vtable entries"),
326 val_print_array_elements (type, valaddr, embedded_offset,
328 recurse, original_value, options, i);
329 fprintf_filtered (stream, "}");
334 /* Array of unspecified length: treat like pointer to first elt. */
335 print_unpacked_pointer (type, elttype, unresolved_elttype, valaddr,
336 embedded_offset, address + embedded_offset,
337 stream, recurse, options);
341 /* c_val_print helper for TYPE_CODE_PTR. */
344 c_val_print_ptr (struct type *type, const gdb_byte *valaddr,
345 int embedded_offset, struct ui_file *stream, int recurse,
346 const struct value *original_value,
347 const struct value_print_options *options)
349 struct gdbarch *arch = get_type_arch (type);
350 int unit_size = gdbarch_addressable_memory_unit_size (arch);
352 if (options->format && options->format != 's')
354 val_print_scalar_formatted (type, valaddr, embedded_offset,
355 original_value, options, 0, stream);
357 else if (options->vtblprint && cp_is_vtbl_ptr_type (type))
359 /* Print the unmangled name if desired. */
360 /* Print vtable entry - we only get here if we ARE using
361 -fvtable_thunks. (Otherwise, look under
362 TYPE_CODE_STRUCT.) */
364 = extract_typed_address (valaddr + embedded_offset, type);
365 struct gdbarch *gdbarch = get_type_arch (type);
367 print_function_pointer_address (options, gdbarch, addr, stream);
371 struct type *unresolved_elttype = TYPE_TARGET_TYPE (type);
372 struct type *elttype = check_typedef (unresolved_elttype);
373 CORE_ADDR addr = unpack_pointer (type,
374 valaddr + embedded_offset * unit_size);
376 print_unpacked_pointer (type, elttype, unresolved_elttype, valaddr,
377 embedded_offset, addr, stream, recurse, options);
381 /* c_val_print helper for TYPE_CODE_STRUCT. */
384 c_val_print_struct (struct type *type, const gdb_byte *valaddr,
385 int embedded_offset, CORE_ADDR address,
386 struct ui_file *stream, int recurse,
387 const struct value *original_value,
388 const struct value_print_options *options)
390 if (options->vtblprint && cp_is_vtbl_ptr_type (type))
392 /* Print the unmangled name if desired. */
393 /* Print vtable entry - we only get here if NOT using
394 -fvtable_thunks. (Otherwise, look under
396 struct gdbarch *gdbarch = get_type_arch (type);
397 int offset = (embedded_offset
398 + TYPE_FIELD_BITPOS (type,
399 VTBL_FNADDR_OFFSET) / 8);
400 struct type *field_type = TYPE_FIELD_TYPE (type, VTBL_FNADDR_OFFSET);
401 CORE_ADDR addr = extract_typed_address (valaddr + offset, field_type);
403 print_function_pointer_address (options, gdbarch, addr, stream);
406 cp_print_value_fields_rtti (type, valaddr,
407 embedded_offset, address,
409 original_value, options,
413 /* c_val_print helper for TYPE_CODE_UNION. */
416 c_val_print_union (struct type *type, const gdb_byte *valaddr,
417 int embedded_offset, CORE_ADDR address,
418 struct ui_file *stream, int recurse,
419 const struct value *original_value,
420 const struct value_print_options *options)
422 if (recurse && !options->unionprint)
424 fprintf_filtered (stream, "{...}");
428 c_val_print_struct (type, valaddr, embedded_offset, address, stream,
429 recurse, original_value, options);
433 /* c_val_print helper for TYPE_CODE_INT. */
436 c_val_print_int (struct type *type, struct type *unresolved_type,
437 const gdb_byte *valaddr, int embedded_offset,
438 struct ui_file *stream, const struct value *original_value,
439 const struct value_print_options *options)
441 struct gdbarch *arch = get_type_arch (type);
442 int unit_size = gdbarch_addressable_memory_unit_size (arch);
444 if (options->format || options->output_format)
446 struct value_print_options opts = *options;
448 opts.format = (options->format ? options->format
449 : options->output_format);
450 val_print_scalar_formatted (type, valaddr, embedded_offset,
451 original_value, &opts, 0, stream);
455 val_print_type_code_int (type, valaddr + embedded_offset * unit_size,
457 /* C and C++ has no single byte int type, char is used
458 instead. Since we don't know whether the value is really
459 intended to be used as an integer or a character, print
460 the character equivalent as well. */
461 if (c_textual_element_type (unresolved_type, options->format))
463 fputs_filtered (" ", stream);
464 LA_PRINT_CHAR (unpack_long (type,
465 valaddr + embedded_offset * unit_size),
466 unresolved_type, stream);
471 /* c_val_print helper for TYPE_CODE_MEMBERPTR. */
474 c_val_print_memberptr (struct type *type, const gdb_byte *valaddr,
475 int embedded_offset, CORE_ADDR address,
476 struct ui_file *stream, int recurse,
477 const struct value *original_value,
478 const struct value_print_options *options)
480 if (!options->format)
482 cp_print_class_member (valaddr + embedded_offset, type, stream, "&");
486 generic_val_print (type, valaddr, embedded_offset, address, stream,
487 recurse, original_value, options, &c_decorations);
491 /* See val_print for a description of the various parameters of this
492 function; they are identical. */
495 c_val_print (struct type *type, const gdb_byte *valaddr,
496 int embedded_offset, CORE_ADDR address,
497 struct ui_file *stream, int recurse,
498 const struct value *original_value,
499 const struct value_print_options *options)
501 struct type *unresolved_type = type;
503 type = check_typedef (type);
504 switch (TYPE_CODE (type))
506 case TYPE_CODE_ARRAY:
507 c_val_print_array (type, valaddr, embedded_offset, address, stream,
508 recurse, original_value, options);
511 case TYPE_CODE_METHODPTR:
512 cplus_print_method_ptr (valaddr + embedded_offset, type, stream);
516 c_val_print_ptr (type, valaddr, embedded_offset, stream, recurse,
517 original_value, options);
520 case TYPE_CODE_UNION:
521 c_val_print_union (type, valaddr, embedded_offset, address, stream,
522 recurse, original_value, options);
525 case TYPE_CODE_STRUCT:
526 c_val_print_struct (type, valaddr, embedded_offset, address, stream,
527 recurse, original_value, options);
531 c_val_print_int (type, unresolved_type, valaddr, embedded_offset, stream,
532 original_value, options);
535 case TYPE_CODE_MEMBERPTR:
536 c_val_print_memberptr (type, valaddr, embedded_offset, address, stream,
537 recurse, original_value, options);
542 case TYPE_CODE_FLAGS:
544 case TYPE_CODE_METHOD:
546 case TYPE_CODE_RANGE:
548 case TYPE_CODE_DECFLOAT:
550 case TYPE_CODE_ERROR:
551 case TYPE_CODE_UNDEF:
552 case TYPE_CODE_COMPLEX:
555 generic_val_print (type, valaddr, embedded_offset, address,
556 stream, recurse, original_value, options,
564 c_value_print (struct value *val, struct ui_file *stream,
565 const struct value_print_options *options)
567 struct type *type, *real_type, *val_type;
568 int full, top, using_enc;
569 struct value_print_options opts = *options;
573 /* If it is a pointer, indicate what it points to.
575 Print type also if it is a reference.
577 C++: if it is a member pointer, we will take care
578 of that when we print it. */
580 /* Preserve the original type before stripping typedefs. We prefer
581 to pass down the original type when possible, but for local
582 checks it is better to look past the typedefs. */
583 val_type = value_type (val);
584 type = check_typedef (val_type);
586 if (TYPE_CODE (type) == TYPE_CODE_PTR
587 || TYPE_CODE (type) == TYPE_CODE_REF)
589 /* Hack: remove (char *) for char strings. Their
590 type is indicated by the quoted string anyway.
591 (Don't use c_textual_element_type here; quoted strings
592 are always exactly (char *), (wchar_t *), or the like. */
593 if (TYPE_CODE (val_type) == TYPE_CODE_PTR
594 && TYPE_NAME (val_type) == NULL
595 && TYPE_NAME (TYPE_TARGET_TYPE (val_type)) != NULL
596 && (strcmp (TYPE_NAME (TYPE_TARGET_TYPE (val_type)),
598 || textual_name (TYPE_NAME (TYPE_TARGET_TYPE (val_type)))))
602 else if (options->objectprint
603 && (TYPE_CODE (TYPE_TARGET_TYPE (type)) == TYPE_CODE_STRUCT))
605 int is_ref = TYPE_CODE (type) == TYPE_CODE_REF;
608 val = value_addr (val);
610 /* Pointer to class, check real type of object. */
611 fprintf_filtered (stream, "(");
613 if (value_entirely_available (val))
615 real_type = value_rtti_indirect_type (val, &full, &top,
619 /* RTTI entry found. */
622 /* Need to adjust pointer value. */
623 val = value_from_pointer (real_type,
624 value_as_address (val) - top);
628 val = value_ref (value_ind (val));
629 type = value_type (val);
632 /* Note: When we look up RTTI entries, we don't get
633 any information on const or volatile
637 type_print (type, "", stream, -1);
638 fprintf_filtered (stream, ") ");
644 fprintf_filtered (stream, "(");
645 type_print (value_type (val), "", stream, -1);
646 fprintf_filtered (stream, ") ");
650 if (!value_initialized (val))
651 fprintf_filtered (stream, " [uninitialized] ");
653 if (options->objectprint && (TYPE_CODE (type) == TYPE_CODE_STRUCT))
655 /* Attempt to determine real type of object. */
656 real_type = value_rtti_type (val, &full, &top, &using_enc);
659 /* We have RTTI information, so use it. */
660 val = value_full_object (val, real_type,
661 full, top, using_enc);
662 fprintf_filtered (stream, "(%s%s) ",
663 TYPE_NAME (real_type),
664 full ? "" : _(" [incomplete object]"));
665 /* Print out object: enclosing type is same as real_type if
667 val_print (value_enclosing_type (val),
668 value_contents_for_printing (val), 0,
669 value_address (val), stream, 0,
670 val, &opts, current_language);
672 /* Note: When we look up RTTI entries, we don't get any
673 information on const or volatile attributes. */
675 else if (type != check_typedef (value_enclosing_type (val)))
677 /* No RTTI information, so let's do our best. */
678 fprintf_filtered (stream, "(%s ?) ",
679 TYPE_NAME (value_enclosing_type (val)));
680 val_print (value_enclosing_type (val),
681 value_contents_for_printing (val), 0,
682 value_address (val), stream, 0,
683 val, &opts, current_language);
686 /* Otherwise, we end up at the return outside this "if". */
689 val_print (val_type, value_contents_for_printing (val),
690 value_embedded_offset (val),
693 val, &opts, current_language);