1 /* Support for printing C values for GDB, the GNU debugger.
3 Copyright (C) 1986-2018 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 =
132 /* Print a pointer based on the type of its target.
134 Arguments to this functions are roughly the same as those in c_val_print.
135 A difference is that ADDRESS is the address to print, with embedded_offset
136 already added. UNRESOLVED_ELTTYPE and ELTTYPE represent the pointed type,
137 respectively before and after check_typedef. */
140 print_unpacked_pointer (struct type *type, struct type *elttype,
141 struct type *unresolved_elttype,
142 const gdb_byte *valaddr, int embedded_offset,
143 CORE_ADDR address, struct ui_file *stream, int recurse,
144 const struct value_print_options *options)
147 struct gdbarch *gdbarch = get_type_arch (type);
149 if (TYPE_CODE (elttype) == TYPE_CODE_FUNC)
151 /* Try to print what function it points to. */
152 print_function_pointer_address (options, gdbarch, address, stream);
156 if (options->symbol_print)
157 want_space = print_address_demangle (options, gdbarch, address, stream,
159 else if (options->addressprint)
161 fputs_filtered (paddress (gdbarch, address), stream);
165 /* For a pointer to a textual type, also print the string
166 pointed to, unless pointer is null. */
168 if (c_textual_element_type (unresolved_elttype, options->format)
172 fputs_filtered (" ", stream);
173 val_print_string (unresolved_elttype, NULL, address, -1, stream, options);
175 else if (cp_is_vtbl_member (type))
177 /* Print vtbl's nicely. */
178 CORE_ADDR vt_address = unpack_pointer (type, valaddr + embedded_offset);
179 struct bound_minimal_symbol msymbol =
180 lookup_minimal_symbol_by_pc (vt_address);
182 /* If 'symbol_print' is set, we did the work above. */
183 if (!options->symbol_print
184 && (msymbol.minsym != NULL)
185 && (vt_address == BMSYMBOL_VALUE_ADDRESS (msymbol)))
188 fputs_filtered (" ", stream);
189 fputs_filtered (" <", stream);
190 fputs_filtered (MSYMBOL_PRINT_NAME (msymbol.minsym), stream);
191 fputs_filtered (">", stream);
195 if (vt_address && options->vtblprint)
197 struct value *vt_val;
198 struct symbol *wsym = NULL;
200 struct block *block = NULL;
203 fputs_filtered (" ", stream);
205 if (msymbol.minsym != NULL)
207 const char *search_name
208 = MSYMBOL_SEARCH_NAME (msymbol.minsym);
209 wsym = lookup_symbol_search_name (search_name, block,
215 wtype = SYMBOL_TYPE (wsym);
219 wtype = unresolved_elttype;
221 vt_val = value_at (wtype, vt_address);
222 common_val_print (vt_val, stream, recurse + 1, options,
224 if (options->prettyformat)
226 fprintf_filtered (stream, "\n");
227 print_spaces_filtered (2 + 2 * recurse, stream);
233 /* c_val_print helper for TYPE_CODE_ARRAY. */
236 c_val_print_array (struct type *type, const gdb_byte *valaddr,
237 int embedded_offset, CORE_ADDR address,
238 struct ui_file *stream, int recurse,
239 struct value *original_value,
240 const struct value_print_options *options)
242 struct type *unresolved_elttype = TYPE_TARGET_TYPE (type);
243 struct type *elttype = check_typedef (unresolved_elttype);
244 struct gdbarch *arch = get_type_arch (type);
245 int unit_size = gdbarch_addressable_memory_unit_size (arch);
247 if (TYPE_LENGTH (type) > 0 && TYPE_LENGTH (unresolved_elttype) > 0)
249 LONGEST low_bound, high_bound;
251 struct gdbarch *gdbarch = get_type_arch (type);
252 enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
253 unsigned int i = 0; /* Number of characters printed. */
255 if (!get_array_bounds (type, &low_bound, &high_bound))
256 error (_("Could not determine the array high bound"));
258 eltlen = TYPE_LENGTH (elttype);
259 len = high_bound - low_bound + 1;
260 if (options->prettyformat_arrays)
262 print_spaces_filtered (2 + 2 * recurse, stream);
265 /* Print arrays of textual chars with a string syntax, as
266 long as the entire array is valid. */
267 if (c_textual_element_type (unresolved_elttype,
269 && value_bytes_available (original_value, embedded_offset,
271 && !value_bits_any_optimized_out (original_value,
272 TARGET_CHAR_BIT * embedded_offset,
273 TARGET_CHAR_BIT * TYPE_LENGTH (type)))
275 int force_ellipses = 0;
277 /* If requested, look for the first null char and only
278 print elements up to it. */
279 if (options->stop_print_at_null)
281 unsigned int temp_len;
285 && temp_len < options->print_max
286 && extract_unsigned_integer (valaddr
287 + embedded_offset * unit_size
289 eltlen, byte_order) != 0);
293 /* Force LA_PRINT_STRING to print ellipses if
294 we've printed the maximum characters and
295 the next character is not \000. */
296 if (temp_len == options->print_max && temp_len < len)
299 = extract_unsigned_integer (valaddr
300 + embedded_offset * unit_size
310 LA_PRINT_STRING (stream, unresolved_elttype,
311 valaddr + embedded_offset * unit_size, len,
312 NULL, force_ellipses, options);
317 fprintf_filtered (stream, "{");
318 /* If this is a virtual function table, print the 0th
319 entry specially, and the rest of the members
321 if (cp_is_vtbl_ptr_type (elttype))
324 fprintf_filtered (stream, _("%d vtable entries"),
331 val_print_array_elements (type, embedded_offset,
333 recurse, original_value, options, i);
334 fprintf_filtered (stream, "}");
339 /* Array of unspecified length: treat like pointer to first elt. */
340 print_unpacked_pointer (type, elttype, unresolved_elttype, valaddr,
341 embedded_offset, address + embedded_offset,
342 stream, recurse, options);
346 /* c_val_print helper for TYPE_CODE_PTR. */
349 c_val_print_ptr (struct type *type, const gdb_byte *valaddr,
350 int embedded_offset, struct ui_file *stream, int recurse,
351 struct value *original_value,
352 const struct value_print_options *options)
354 struct gdbarch *arch = get_type_arch (type);
355 int unit_size = gdbarch_addressable_memory_unit_size (arch);
357 if (options->format && options->format != 's')
359 val_print_scalar_formatted (type, embedded_offset,
360 original_value, options, 0, stream);
362 else if (options->vtblprint && cp_is_vtbl_ptr_type (type))
364 /* Print the unmangled name if desired. */
365 /* Print vtable entry - we only get here if we ARE using
366 -fvtable_thunks. (Otherwise, look under
367 TYPE_CODE_STRUCT.) */
369 = extract_typed_address (valaddr + embedded_offset, type);
370 struct gdbarch *gdbarch = get_type_arch (type);
372 print_function_pointer_address (options, gdbarch, addr, stream);
376 struct type *unresolved_elttype = TYPE_TARGET_TYPE (type);
377 struct type *elttype = check_typedef (unresolved_elttype);
378 CORE_ADDR addr = unpack_pointer (type,
379 valaddr + embedded_offset * unit_size);
381 print_unpacked_pointer (type, elttype, unresolved_elttype, valaddr,
382 embedded_offset, addr, stream, recurse, options);
386 /* c_val_print helper for TYPE_CODE_STRUCT. */
389 c_val_print_struct (struct type *type, const gdb_byte *valaddr,
390 int embedded_offset, CORE_ADDR address,
391 struct ui_file *stream, int recurse,
392 struct value *original_value,
393 const struct value_print_options *options)
395 if (options->vtblprint && cp_is_vtbl_ptr_type (type))
397 /* Print the unmangled name if desired. */
398 /* Print vtable entry - we only get here if NOT using
399 -fvtable_thunks. (Otherwise, look under
401 struct gdbarch *gdbarch = get_type_arch (type);
402 int offset = (embedded_offset
403 + TYPE_FIELD_BITPOS (type,
404 VTBL_FNADDR_OFFSET) / 8);
405 struct type *field_type = TYPE_FIELD_TYPE (type, VTBL_FNADDR_OFFSET);
406 CORE_ADDR addr = extract_typed_address (valaddr + offset, field_type);
408 print_function_pointer_address (options, gdbarch, addr, stream);
411 cp_print_value_fields_rtti (type, valaddr,
412 embedded_offset, address,
414 original_value, options,
418 /* c_val_print helper for TYPE_CODE_UNION. */
421 c_val_print_union (struct type *type, const gdb_byte *valaddr,
422 int embedded_offset, CORE_ADDR address,
423 struct ui_file *stream, int recurse,
424 struct value *original_value,
425 const struct value_print_options *options)
427 if (recurse && !options->unionprint)
429 fprintf_filtered (stream, "{...}");
433 c_val_print_struct (type, valaddr, embedded_offset, address, stream,
434 recurse, original_value, options);
438 /* c_val_print helper for TYPE_CODE_INT. */
441 c_val_print_int (struct type *type, struct type *unresolved_type,
442 const gdb_byte *valaddr, int embedded_offset,
443 struct ui_file *stream, struct value *original_value,
444 const struct value_print_options *options)
446 struct gdbarch *arch = get_type_arch (type);
447 int unit_size = gdbarch_addressable_memory_unit_size (arch);
449 if (options->format || options->output_format)
451 struct value_print_options opts = *options;
453 opts.format = (options->format ? options->format
454 : options->output_format);
455 val_print_scalar_formatted (type, embedded_offset,
456 original_value, &opts, 0, stream);
460 val_print_scalar_formatted (type, embedded_offset,
461 original_value, options, 0, stream);
462 /* C and C++ has no single byte int type, char is used
463 instead. Since we don't know whether the value is really
464 intended to be used as an integer or a character, print
465 the character equivalent as well. */
466 if (c_textual_element_type (unresolved_type, options->format))
468 fputs_filtered (" ", stream);
469 LA_PRINT_CHAR (unpack_long (type,
470 valaddr + embedded_offset * unit_size),
471 unresolved_type, stream);
476 /* c_val_print helper for TYPE_CODE_MEMBERPTR. */
479 c_val_print_memberptr (struct type *type, const gdb_byte *valaddr,
480 int embedded_offset, CORE_ADDR address,
481 struct ui_file *stream, int recurse,
482 struct value *original_value,
483 const struct value_print_options *options)
485 if (!options->format)
487 cp_print_class_member (valaddr + embedded_offset, type, stream, "&");
491 generic_val_print (type, embedded_offset, address, stream,
492 recurse, original_value, options, &c_decorations);
496 /* See val_print for a description of the various parameters of this
497 function; they are identical. */
500 c_val_print (struct type *type,
501 int embedded_offset, CORE_ADDR address,
502 struct ui_file *stream, int recurse,
503 struct value *original_value,
504 const struct value_print_options *options)
506 struct type *unresolved_type = type;
507 const gdb_byte *valaddr = value_contents_for_printing (original_value);
509 type = check_typedef (type);
510 switch (TYPE_CODE (type))
512 case TYPE_CODE_ARRAY:
513 c_val_print_array (type, valaddr, embedded_offset, address, stream,
514 recurse, original_value, options);
517 case TYPE_CODE_METHODPTR:
518 cplus_print_method_ptr (valaddr + embedded_offset, type, stream);
522 c_val_print_ptr (type, valaddr, embedded_offset, stream, recurse,
523 original_value, options);
526 case TYPE_CODE_UNION:
527 c_val_print_union (type, valaddr, embedded_offset, address, stream,
528 recurse, original_value, options);
531 case TYPE_CODE_STRUCT:
532 c_val_print_struct (type, valaddr, embedded_offset, address, stream,
533 recurse, original_value, options);
537 c_val_print_int (type, unresolved_type, valaddr, embedded_offset, stream,
538 original_value, options);
541 case TYPE_CODE_MEMBERPTR:
542 c_val_print_memberptr (type, valaddr, embedded_offset, address, stream,
543 recurse, original_value, options);
547 case TYPE_CODE_RVALUE_REF:
549 case TYPE_CODE_FLAGS:
551 case TYPE_CODE_METHOD:
553 case TYPE_CODE_RANGE:
555 case TYPE_CODE_DECFLOAT:
557 case TYPE_CODE_ERROR:
558 case TYPE_CODE_UNDEF:
559 case TYPE_CODE_COMPLEX:
562 generic_val_print (type, embedded_offset, address,
563 stream, recurse, original_value, options,
571 c_value_print (struct value *val, struct ui_file *stream,
572 const struct value_print_options *options)
574 struct type *type, *real_type, *val_type;
577 struct value_print_options opts = *options;
581 /* If it is a pointer, indicate what it points to.
583 Print type also if it is a reference.
585 C++: if it is a member pointer, we will take care
586 of that when we print it. */
588 /* Preserve the original type before stripping typedefs. We prefer
589 to pass down the original type when possible, but for local
590 checks it is better to look past the typedefs. */
591 val_type = value_type (val);
592 type = check_typedef (val_type);
594 if (TYPE_CODE (type) == TYPE_CODE_PTR || TYPE_IS_REFERENCE (type))
596 /* Hack: remove (char *) for char strings. Their
597 type is indicated by the quoted string anyway.
598 (Don't use c_textual_element_type here; quoted strings
599 are always exactly (char *), (wchar_t *), or the like. */
600 if (TYPE_CODE (val_type) == TYPE_CODE_PTR
601 && TYPE_NAME (val_type) == NULL
602 && TYPE_NAME (TYPE_TARGET_TYPE (val_type)) != NULL
603 && (strcmp (TYPE_NAME (TYPE_TARGET_TYPE (val_type)),
605 || textual_name (TYPE_NAME (TYPE_TARGET_TYPE (val_type)))))
609 else if (options->objectprint
610 && (TYPE_CODE (TYPE_TARGET_TYPE (type)) == TYPE_CODE_STRUCT))
612 int is_ref = TYPE_IS_REFERENCE (type);
613 enum type_code refcode = TYPE_CODE_UNDEF;
617 val = value_addr (val);
618 refcode = TYPE_CODE (type);
621 /* Pointer to class, check real type of object. */
622 fprintf_filtered (stream, "(");
624 if (value_entirely_available (val))
626 real_type = value_rtti_indirect_type (val, &full, &top,
630 /* RTTI entry found. */
633 /* Need to adjust pointer value. */
634 val = value_from_pointer (real_type,
635 value_as_address (val) - top);
637 /* Note: When we look up RTTI entries, we don't get
638 any information on const or volatile
645 val = value_ref (value_ind (val), refcode);
646 type = value_type (val);
649 type_print (type, "", stream, -1);
650 fprintf_filtered (stream, ") ");
656 fprintf_filtered (stream, "(");
657 type_print (value_type (val), "", stream, -1);
658 fprintf_filtered (stream, ") ");
662 if (!value_initialized (val))
663 fprintf_filtered (stream, " [uninitialized] ");
665 if (options->objectprint && (TYPE_CODE (type) == TYPE_CODE_STRUCT))
667 /* Attempt to determine real type of object. */
668 real_type = value_rtti_type (val, &full, &top, &using_enc);
671 /* We have RTTI information, so use it. */
672 val = value_full_object (val, real_type,
673 full, top, using_enc);
674 fprintf_filtered (stream, "(%s%s) ",
675 TYPE_NAME (real_type),
676 full ? "" : _(" [incomplete object]"));
677 /* Print out object: enclosing type is same as real_type if
679 val_print (value_enclosing_type (val),
681 value_address (val), stream, 0,
682 val, &opts, current_language);
684 /* Note: When we look up RTTI entries, we don't get any
685 information on const or volatile attributes. */
687 else if (type != check_typedef (value_enclosing_type (val)))
689 /* No RTTI information, so let's do our best. */
690 fprintf_filtered (stream, "(%s ?) ",
691 TYPE_NAME (value_enclosing_type (val)));
692 val_print (value_enclosing_type (val),
694 value_address (val), stream, 0,
695 val, &opts, current_language);
698 /* Otherwise, we end up at the return outside this "if". */
702 value_embedded_offset (val),
705 val, &opts, current_language);