1 /* Support for printing C values for GDB, the GNU debugger.
3 Copyright (C) 1986-2016 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;
201 struct field_of_this_result is_this_fld;
204 fputs_filtered (" ", stream);
206 if (msymbol.minsym != NULL)
207 wsym = lookup_symbol (MSYMBOL_LINKAGE_NAME(msymbol.minsym), block,
208 VAR_DOMAIN, &is_this_fld).symbol;
212 wtype = SYMBOL_TYPE (wsym);
216 wtype = unresolved_elttype;
218 vt_val = value_at (wtype, vt_address);
219 common_val_print (vt_val, stream, recurse + 1, options,
221 if (options->prettyformat)
223 fprintf_filtered (stream, "\n");
224 print_spaces_filtered (2 + 2 * recurse, stream);
230 /* c_val_print helper for TYPE_CODE_ARRAY. */
233 c_val_print_array (struct type *type, const gdb_byte *valaddr,
234 int embedded_offset, CORE_ADDR address,
235 struct ui_file *stream, int recurse,
236 const struct value *original_value,
237 const struct value_print_options *options)
239 struct type *unresolved_elttype = TYPE_TARGET_TYPE (type);
240 struct type *elttype = check_typedef (unresolved_elttype);
241 struct gdbarch *arch = get_type_arch (type);
242 int unit_size = gdbarch_addressable_memory_unit_size (arch);
244 if (TYPE_LENGTH (type) > 0 && TYPE_LENGTH (unresolved_elttype) > 0)
246 LONGEST low_bound, high_bound;
248 struct gdbarch *gdbarch = get_type_arch (type);
249 enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
250 unsigned int i = 0; /* Number of characters printed. */
252 if (!get_array_bounds (type, &low_bound, &high_bound))
253 error (_("Could not determine the array high bound"));
255 eltlen = TYPE_LENGTH (elttype);
256 len = high_bound - low_bound + 1;
257 if (options->prettyformat_arrays)
259 print_spaces_filtered (2 + 2 * recurse, stream);
262 /* Print arrays of textual chars with a string syntax, as
263 long as the entire array is valid. */
264 if (c_textual_element_type (unresolved_elttype,
266 && value_bytes_available (original_value, embedded_offset,
268 && !value_bits_any_optimized_out (original_value,
269 TARGET_CHAR_BIT * embedded_offset,
270 TARGET_CHAR_BIT * TYPE_LENGTH (type)))
272 int force_ellipses = 0;
274 /* If requested, look for the first null char and only
275 print elements up to it. */
276 if (options->stop_print_at_null)
278 unsigned int temp_len;
282 && temp_len < options->print_max
283 && extract_unsigned_integer (valaddr
284 + embedded_offset * unit_size
286 eltlen, byte_order) != 0);
290 /* Force LA_PRINT_STRING to print ellipses if
291 we've printed the maximum characters and
292 the next character is not \000. */
293 if (temp_len == options->print_max && temp_len < len)
296 = extract_unsigned_integer (valaddr
297 + embedded_offset * unit_size
307 LA_PRINT_STRING (stream, unresolved_elttype,
308 valaddr + embedded_offset * unit_size, len,
309 NULL, force_ellipses, options);
314 fprintf_filtered (stream, "{");
315 /* If this is a virtual function table, print the 0th
316 entry specially, and the rest of the members
318 if (cp_is_vtbl_ptr_type (elttype))
321 fprintf_filtered (stream, _("%d vtable entries"),
328 val_print_array_elements (type, valaddr, embedded_offset,
330 recurse, original_value, options, i);
331 fprintf_filtered (stream, "}");
336 /* Array of unspecified length: treat like pointer to first elt. */
337 print_unpacked_pointer (type, elttype, unresolved_elttype, valaddr,
338 embedded_offset, address + embedded_offset,
339 stream, recurse, options);
343 /* c_val_print helper for TYPE_CODE_PTR. */
346 c_val_print_ptr (struct type *type, const gdb_byte *valaddr,
347 int embedded_offset, struct ui_file *stream, int recurse,
348 const struct value *original_value,
349 const struct value_print_options *options)
351 struct gdbarch *arch = get_type_arch (type);
352 int unit_size = gdbarch_addressable_memory_unit_size (arch);
354 if (options->format && options->format != 's')
356 val_print_scalar_formatted (type, valaddr, embedded_offset,
357 original_value, options, 0, stream);
359 else if (options->vtblprint && cp_is_vtbl_ptr_type (type))
361 /* Print the unmangled name if desired. */
362 /* Print vtable entry - we only get here if we ARE using
363 -fvtable_thunks. (Otherwise, look under
364 TYPE_CODE_STRUCT.) */
366 = extract_typed_address (valaddr + embedded_offset, type);
367 struct gdbarch *gdbarch = get_type_arch (type);
369 print_function_pointer_address (options, gdbarch, addr, stream);
373 struct type *unresolved_elttype = TYPE_TARGET_TYPE (type);
374 struct type *elttype = check_typedef (unresolved_elttype);
375 CORE_ADDR addr = unpack_pointer (type,
376 valaddr + embedded_offset * unit_size);
378 print_unpacked_pointer (type, elttype, unresolved_elttype, valaddr,
379 embedded_offset, addr, stream, recurse, options);
383 /* c_val_print helper for TYPE_CODE_STRUCT. */
386 c_val_print_struct (struct type *type, const gdb_byte *valaddr,
387 int embedded_offset, CORE_ADDR address,
388 struct ui_file *stream, int recurse,
389 const struct value *original_value,
390 const struct value_print_options *options)
392 if (options->vtblprint && cp_is_vtbl_ptr_type (type))
394 /* Print the unmangled name if desired. */
395 /* Print vtable entry - we only get here if NOT using
396 -fvtable_thunks. (Otherwise, look under
398 struct gdbarch *gdbarch = get_type_arch (type);
399 int offset = (embedded_offset
400 + TYPE_FIELD_BITPOS (type,
401 VTBL_FNADDR_OFFSET) / 8);
402 struct type *field_type = TYPE_FIELD_TYPE (type, VTBL_FNADDR_OFFSET);
403 CORE_ADDR addr = extract_typed_address (valaddr + offset, field_type);
405 print_function_pointer_address (options, gdbarch, addr, stream);
408 cp_print_value_fields_rtti (type, valaddr,
409 embedded_offset, address,
411 original_value, options,
415 /* c_val_print helper for TYPE_CODE_UNION. */
418 c_val_print_union (struct type *type, const gdb_byte *valaddr,
419 int embedded_offset, CORE_ADDR address,
420 struct ui_file *stream, int recurse,
421 const struct value *original_value,
422 const struct value_print_options *options)
424 if (recurse && !options->unionprint)
426 fprintf_filtered (stream, "{...}");
430 c_val_print_struct (type, valaddr, embedded_offset, address, stream,
431 recurse, original_value, options);
435 /* c_val_print helper for TYPE_CODE_INT. */
438 c_val_print_int (struct type *type, struct type *unresolved_type,
439 const gdb_byte *valaddr, int embedded_offset,
440 struct ui_file *stream, const struct value *original_value,
441 const struct value_print_options *options)
443 struct gdbarch *arch = get_type_arch (type);
444 int unit_size = gdbarch_addressable_memory_unit_size (arch);
446 if (options->format || options->output_format)
448 struct value_print_options opts = *options;
450 opts.format = (options->format ? options->format
451 : options->output_format);
452 val_print_scalar_formatted (type, valaddr, embedded_offset,
453 original_value, &opts, 0, stream);
457 val_print_type_code_int (type, valaddr + embedded_offset * unit_size,
459 /* C and C++ has no single byte int type, char is used
460 instead. Since we don't know whether the value is really
461 intended to be used as an integer or a character, print
462 the character equivalent as well. */
463 if (c_textual_element_type (unresolved_type, options->format))
465 fputs_filtered (" ", stream);
466 LA_PRINT_CHAR (unpack_long (type,
467 valaddr + embedded_offset * unit_size),
468 unresolved_type, stream);
473 /* c_val_print helper for TYPE_CODE_MEMBERPTR. */
476 c_val_print_memberptr (struct type *type, const gdb_byte *valaddr,
477 int embedded_offset, CORE_ADDR address,
478 struct ui_file *stream, int recurse,
479 const struct value *original_value,
480 const struct value_print_options *options)
482 if (!options->format)
484 cp_print_class_member (valaddr + embedded_offset, type, stream, "&");
488 generic_val_print (type, valaddr, embedded_offset, address, stream,
489 recurse, original_value, options, &c_decorations);
493 /* See val_print for a description of the various parameters of this
494 function; they are identical. */
497 c_val_print (struct type *type, const gdb_byte *valaddr,
498 int embedded_offset, CORE_ADDR address,
499 struct ui_file *stream, int recurse,
500 const struct value *original_value,
501 const struct value_print_options *options)
503 struct type *unresolved_type = type;
505 type = check_typedef (type);
506 switch (TYPE_CODE (type))
508 case TYPE_CODE_ARRAY:
509 c_val_print_array (type, valaddr, embedded_offset, address, stream,
510 recurse, original_value, options);
513 case TYPE_CODE_METHODPTR:
514 cplus_print_method_ptr (valaddr + embedded_offset, type, stream);
518 c_val_print_ptr (type, valaddr, embedded_offset, stream, recurse,
519 original_value, options);
522 case TYPE_CODE_UNION:
523 c_val_print_union (type, valaddr, embedded_offset, address, stream,
524 recurse, original_value, options);
527 case TYPE_CODE_STRUCT:
528 c_val_print_struct (type, valaddr, embedded_offset, address, stream,
529 recurse, original_value, options);
533 c_val_print_int (type, unresolved_type, valaddr, embedded_offset, stream,
534 original_value, options);
537 case TYPE_CODE_MEMBERPTR:
538 c_val_print_memberptr (type, valaddr, embedded_offset, address, stream,
539 recurse, original_value, options);
544 case TYPE_CODE_FLAGS:
546 case TYPE_CODE_METHOD:
548 case TYPE_CODE_RANGE:
550 case TYPE_CODE_DECFLOAT:
552 case TYPE_CODE_ERROR:
553 case TYPE_CODE_UNDEF:
554 case TYPE_CODE_COMPLEX:
557 generic_val_print (type, valaddr, embedded_offset, address,
558 stream, recurse, original_value, options,
566 c_value_print (struct value *val, struct ui_file *stream,
567 const struct value_print_options *options)
569 struct type *type, *real_type, *val_type;
570 int full, top, using_enc;
571 struct value_print_options opts = *options;
575 /* If it is a pointer, indicate what it points to.
577 Print type also if it is a reference.
579 C++: if it is a member pointer, we will take care
580 of that when we print it. */
582 /* Preserve the original type before stripping typedefs. We prefer
583 to pass down the original type when possible, but for local
584 checks it is better to look past the typedefs. */
585 val_type = value_type (val);
586 type = check_typedef (val_type);
588 if (TYPE_CODE (type) == TYPE_CODE_PTR
589 || TYPE_CODE (type) == TYPE_CODE_REF)
591 /* Hack: remove (char *) for char strings. Their
592 type is indicated by the quoted string anyway.
593 (Don't use c_textual_element_type here; quoted strings
594 are always exactly (char *), (wchar_t *), or the like. */
595 if (TYPE_CODE (val_type) == TYPE_CODE_PTR
596 && TYPE_NAME (val_type) == NULL
597 && TYPE_NAME (TYPE_TARGET_TYPE (val_type)) != NULL
598 && (strcmp (TYPE_NAME (TYPE_TARGET_TYPE (val_type)),
600 || textual_name (TYPE_NAME (TYPE_TARGET_TYPE (val_type)))))
604 else if (options->objectprint
605 && (TYPE_CODE (TYPE_TARGET_TYPE (type)) == TYPE_CODE_STRUCT))
607 int is_ref = TYPE_CODE (type) == TYPE_CODE_REF;
610 val = value_addr (val);
612 /* Pointer to class, check real type of object. */
613 fprintf_filtered (stream, "(");
615 if (value_entirely_available (val))
617 real_type = value_rtti_indirect_type (val, &full, &top,
621 /* RTTI entry found. */
624 /* Need to adjust pointer value. */
625 val = value_from_pointer (real_type,
626 value_as_address (val) - top);
628 /* Note: When we look up RTTI entries, we don't get
629 any information on const or volatile
636 val = value_ref (value_ind (val));
637 type = value_type (val);
640 type_print (type, "", stream, -1);
641 fprintf_filtered (stream, ") ");
647 fprintf_filtered (stream, "(");
648 type_print (value_type (val), "", stream, -1);
649 fprintf_filtered (stream, ") ");
653 if (!value_initialized (val))
654 fprintf_filtered (stream, " [uninitialized] ");
656 if (options->objectprint && (TYPE_CODE (type) == TYPE_CODE_STRUCT))
658 /* Attempt to determine real type of object. */
659 real_type = value_rtti_type (val, &full, &top, &using_enc);
662 /* We have RTTI information, so use it. */
663 val = value_full_object (val, real_type,
664 full, top, using_enc);
665 fprintf_filtered (stream, "(%s%s) ",
666 TYPE_NAME (real_type),
667 full ? "" : _(" [incomplete object]"));
668 /* Print out object: enclosing type is same as real_type if
670 val_print (value_enclosing_type (val),
671 value_contents_for_printing (val), 0,
672 value_address (val), stream, 0,
673 val, &opts, current_language);
675 /* Note: When we look up RTTI entries, we don't get any
676 information on const or volatile attributes. */
678 else if (type != check_typedef (value_enclosing_type (val)))
680 /* No RTTI information, so let's do our best. */
681 fprintf_filtered (stream, "(%s ?) ",
682 TYPE_NAME (value_enclosing_type (val)));
683 val_print (value_enclosing_type (val),
684 value_contents_for_printing (val), 0,
685 value_address (val), stream, 0,
686 val, &opts, current_language);
689 /* Otherwise, we end up at the return outside this "if". */
692 val_print (val_type, value_contents_for_printing (val),
693 value_embedded_offset (val),
696 val, &opts, current_language);