1 /* Support for printing C values for GDB, the GNU debugger.
3 Copyright (C) 1986-2019 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;
202 fputs_filtered (" ", stream);
204 if (msymbol.minsym != NULL)
206 const char *search_name
207 = MSYMBOL_SEARCH_NAME (msymbol.minsym);
208 wsym = lookup_symbol_search_name (search_name, NULL,
214 wtype = SYMBOL_TYPE (wsym);
218 wtype = unresolved_elttype;
220 vt_val = value_at (wtype, vt_address);
221 common_val_print (vt_val, stream, recurse + 1, options,
223 if (options->prettyformat)
225 fprintf_filtered (stream, "\n");
226 print_spaces_filtered (2 + 2 * recurse, stream);
232 /* c_val_print helper for TYPE_CODE_ARRAY. */
235 c_val_print_array (struct type *type, const gdb_byte *valaddr,
236 int embedded_offset, CORE_ADDR address,
237 struct ui_file *stream, int recurse,
238 struct value *original_value,
239 const struct value_print_options *options)
241 struct type *unresolved_elttype = TYPE_TARGET_TYPE (type);
242 struct type *elttype = check_typedef (unresolved_elttype);
243 struct gdbarch *arch = get_type_arch (type);
244 int unit_size = gdbarch_addressable_memory_unit_size (arch);
246 if (TYPE_LENGTH (type) > 0 && TYPE_LENGTH (unresolved_elttype) > 0)
248 LONGEST low_bound, high_bound;
250 struct gdbarch *gdbarch = get_type_arch (type);
251 enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
252 unsigned int i = 0; /* Number of characters printed. */
254 if (!get_array_bounds (type, &low_bound, &high_bound))
255 error (_("Could not determine the array high bound"));
257 eltlen = TYPE_LENGTH (elttype);
258 len = high_bound - low_bound + 1;
259 if (options->prettyformat_arrays)
261 print_spaces_filtered (2 + 2 * recurse, stream);
264 /* Print arrays of textual chars with a string syntax, as
265 long as the entire array is valid. */
266 if (c_textual_element_type (unresolved_elttype,
268 && value_bytes_available (original_value, embedded_offset,
270 && !value_bits_any_optimized_out (original_value,
271 TARGET_CHAR_BIT * embedded_offset,
272 TARGET_CHAR_BIT * TYPE_LENGTH (type)))
274 int force_ellipses = 0;
276 /* If requested, look for the first null char and only
277 print elements up to it. */
278 if (options->stop_print_at_null)
280 unsigned int temp_len;
284 && temp_len < options->print_max
285 && extract_unsigned_integer (valaddr
286 + embedded_offset * unit_size
288 eltlen, byte_order) != 0);
292 /* Force LA_PRINT_STRING to print ellipses if
293 we've printed the maximum characters and
294 the next character is not \000. */
295 if (temp_len == options->print_max && temp_len < len)
298 = extract_unsigned_integer (valaddr
299 + embedded_offset * unit_size
309 LA_PRINT_STRING (stream, unresolved_elttype,
310 valaddr + embedded_offset * unit_size, len,
311 NULL, force_ellipses, options);
316 fprintf_filtered (stream, "{");
317 /* If this is a virtual function table, print the 0th
318 entry specially, and the rest of the members
320 if (cp_is_vtbl_ptr_type (elttype))
323 fprintf_filtered (stream, _("%d vtable entries"),
330 val_print_array_elements (type, embedded_offset,
332 recurse, original_value, options, i);
333 fprintf_filtered (stream, "}");
338 /* Array of unspecified length: treat like pointer to first elt. */
339 print_unpacked_pointer (type, elttype, unresolved_elttype, valaddr,
340 embedded_offset, address + embedded_offset,
341 stream, recurse, options);
345 /* c_val_print helper for TYPE_CODE_PTR. */
348 c_val_print_ptr (struct type *type, const gdb_byte *valaddr,
349 int embedded_offset, struct ui_file *stream, int recurse,
350 struct value *original_value,
351 const struct value_print_options *options)
353 struct gdbarch *arch = get_type_arch (type);
354 int unit_size = gdbarch_addressable_memory_unit_size (arch);
356 if (options->format && options->format != 's')
358 val_print_scalar_formatted (type, embedded_offset,
359 original_value, options, 0, stream);
361 else if (options->vtblprint && cp_is_vtbl_ptr_type (type))
363 /* Print the unmangled name if desired. */
364 /* Print vtable entry - we only get here if we ARE using
365 -fvtable_thunks. (Otherwise, look under
366 TYPE_CODE_STRUCT.) */
368 = extract_typed_address (valaddr + embedded_offset, type);
369 struct gdbarch *gdbarch = get_type_arch (type);
371 print_function_pointer_address (options, gdbarch, addr, stream);
375 struct type *unresolved_elttype = TYPE_TARGET_TYPE (type);
376 struct type *elttype = check_typedef (unresolved_elttype);
377 CORE_ADDR addr = unpack_pointer (type,
378 valaddr + embedded_offset * unit_size);
380 print_unpacked_pointer (type, elttype, unresolved_elttype, valaddr,
381 embedded_offset, addr, stream, recurse, options);
385 /* c_val_print helper for TYPE_CODE_STRUCT. */
388 c_val_print_struct (struct type *type, const gdb_byte *valaddr,
389 int embedded_offset, CORE_ADDR address,
390 struct ui_file *stream, int recurse,
391 struct value *original_value,
392 const struct value_print_options *options)
394 if (options->vtblprint && cp_is_vtbl_ptr_type (type))
396 /* Print the unmangled name if desired. */
397 /* Print vtable entry - we only get here if NOT using
398 -fvtable_thunks. (Otherwise, look under
400 struct gdbarch *gdbarch = get_type_arch (type);
401 int offset = (embedded_offset
402 + TYPE_FIELD_BITPOS (type,
403 VTBL_FNADDR_OFFSET) / 8);
404 struct type *field_type = TYPE_FIELD_TYPE (type, VTBL_FNADDR_OFFSET);
405 CORE_ADDR addr = extract_typed_address (valaddr + offset, field_type);
407 print_function_pointer_address (options, gdbarch, addr, stream);
410 cp_print_value_fields_rtti (type, valaddr,
411 embedded_offset, address,
413 original_value, options,
417 /* c_val_print helper for TYPE_CODE_UNION. */
420 c_val_print_union (struct type *type, const gdb_byte *valaddr,
421 int embedded_offset, CORE_ADDR address,
422 struct ui_file *stream, int recurse,
423 struct value *original_value,
424 const struct value_print_options *options)
426 if (recurse && !options->unionprint)
428 fprintf_filtered (stream, "{...}");
432 c_val_print_struct (type, valaddr, embedded_offset, address, stream,
433 recurse, original_value, options);
437 /* c_val_print helper for TYPE_CODE_INT. */
440 c_val_print_int (struct type *type, struct type *unresolved_type,
441 const gdb_byte *valaddr, int embedded_offset,
442 struct ui_file *stream, struct value *original_value,
443 const struct value_print_options *options)
445 struct gdbarch *arch = get_type_arch (type);
446 int unit_size = gdbarch_addressable_memory_unit_size (arch);
448 if (options->format || options->output_format)
450 struct value_print_options opts = *options;
452 opts.format = (options->format ? options->format
453 : options->output_format);
454 val_print_scalar_formatted (type, embedded_offset,
455 original_value, &opts, 0, stream);
459 val_print_scalar_formatted (type, embedded_offset,
460 original_value, options, 0, stream);
461 /* C and C++ has no single byte int type, char is used
462 instead. Since we don't know whether the value is really
463 intended to be used as an integer or a character, print
464 the character equivalent as well. */
465 if (c_textual_element_type (unresolved_type, options->format))
467 fputs_filtered (" ", stream);
468 LA_PRINT_CHAR (unpack_long (type,
469 valaddr + embedded_offset * unit_size),
470 unresolved_type, stream);
475 /* c_val_print helper for TYPE_CODE_MEMBERPTR. */
478 c_val_print_memberptr (struct type *type, const gdb_byte *valaddr,
479 int embedded_offset, CORE_ADDR address,
480 struct ui_file *stream, int recurse,
481 struct value *original_value,
482 const struct value_print_options *options)
484 if (!options->format)
486 cp_print_class_member (valaddr + embedded_offset, type, stream, "&");
490 generic_val_print (type, embedded_offset, address, stream,
491 recurse, original_value, options, &c_decorations);
495 /* See val_print for a description of the various parameters of this
496 function; they are identical. */
499 c_val_print (struct type *type,
500 int embedded_offset, CORE_ADDR address,
501 struct ui_file *stream, int recurse,
502 struct value *original_value,
503 const struct value_print_options *options)
505 struct type *unresolved_type = type;
506 const gdb_byte *valaddr = value_contents_for_printing (original_value);
508 type = check_typedef (type);
509 switch (TYPE_CODE (type))
511 case TYPE_CODE_ARRAY:
512 c_val_print_array (type, valaddr, embedded_offset, address, stream,
513 recurse, original_value, options);
516 case TYPE_CODE_METHODPTR:
517 cplus_print_method_ptr (valaddr + embedded_offset, type, stream);
521 c_val_print_ptr (type, valaddr, embedded_offset, stream, recurse,
522 original_value, options);
525 case TYPE_CODE_UNION:
526 c_val_print_union (type, valaddr, embedded_offset, address, stream,
527 recurse, original_value, options);
530 case TYPE_CODE_STRUCT:
531 c_val_print_struct (type, valaddr, embedded_offset, address, stream,
532 recurse, original_value, options);
536 c_val_print_int (type, unresolved_type, valaddr, embedded_offset, stream,
537 original_value, options);
540 case TYPE_CODE_MEMBERPTR:
541 c_val_print_memberptr (type, valaddr, embedded_offset, address, stream,
542 recurse, original_value, options);
546 case TYPE_CODE_RVALUE_REF:
548 case TYPE_CODE_FLAGS:
550 case TYPE_CODE_METHOD:
552 case TYPE_CODE_RANGE:
554 case TYPE_CODE_DECFLOAT:
556 case TYPE_CODE_ERROR:
557 case TYPE_CODE_UNDEF:
558 case TYPE_CODE_COMPLEX:
561 generic_val_print (type, embedded_offset, address,
562 stream, recurse, original_value, options,
569 c_value_print (struct value *val, struct ui_file *stream,
570 const struct value_print_options *options)
572 struct type *type, *real_type, *val_type;
575 struct value_print_options opts = *options;
579 /* If it is a pointer, indicate what it points to.
581 Print type also if it is a reference.
583 C++: if it is a member pointer, we will take care
584 of that when we print it. */
586 /* Preserve the original type before stripping typedefs. We prefer
587 to pass down the original type when possible, but for local
588 checks it is better to look past the typedefs. */
589 val_type = value_type (val);
590 type = check_typedef (val_type);
592 if (TYPE_CODE (type) == TYPE_CODE_PTR || TYPE_IS_REFERENCE (type))
594 /* Hack: remove (char *) for char strings. Their
595 type is indicated by the quoted string anyway.
596 (Don't use c_textual_element_type here; quoted strings
597 are always exactly (char *), (wchar_t *), or the like. */
598 if (TYPE_CODE (val_type) == TYPE_CODE_PTR
599 && TYPE_NAME (val_type) == NULL
600 && TYPE_NAME (TYPE_TARGET_TYPE (val_type)) != NULL
601 && (strcmp (TYPE_NAME (TYPE_TARGET_TYPE (val_type)),
603 || textual_name (TYPE_NAME (TYPE_TARGET_TYPE (val_type)))))
607 else if (options->objectprint
608 && (TYPE_CODE (TYPE_TARGET_TYPE (type)) == TYPE_CODE_STRUCT))
610 int is_ref = TYPE_IS_REFERENCE (type);
611 enum type_code refcode = TYPE_CODE_UNDEF;
615 val = value_addr (val);
616 refcode = TYPE_CODE (type);
619 /* Pointer to class, check real type of object. */
620 fprintf_filtered (stream, "(");
622 if (value_entirely_available (val))
624 real_type = value_rtti_indirect_type (val, &full, &top,
628 /* RTTI entry found. */
631 /* Need to adjust pointer value. */
632 val = value_from_pointer (real_type,
633 value_as_address (val) - top);
635 /* Note: When we look up RTTI entries, we don't get
636 any information on const or volatile
643 val = value_ref (value_ind (val), refcode);
644 type = value_type (val);
647 type_print (type, "", stream, -1);
648 fprintf_filtered (stream, ") ");
654 fprintf_filtered (stream, "(");
655 type_print (value_type (val), "", stream, -1);
656 fprintf_filtered (stream, ") ");
660 if (!value_initialized (val))
661 fprintf_filtered (stream, " [uninitialized] ");
663 if (options->objectprint && (TYPE_CODE (type) == TYPE_CODE_STRUCT))
665 /* Attempt to determine real type of object. */
666 real_type = value_rtti_type (val, &full, &top, &using_enc);
669 /* We have RTTI information, so use it. */
670 val = value_full_object (val, real_type,
671 full, top, using_enc);
672 fprintf_filtered (stream, "(%s%s) ",
673 TYPE_NAME (real_type),
674 full ? "" : _(" [incomplete object]"));
675 /* Print out object: enclosing type is same as real_type if
677 val_print (value_enclosing_type (val),
679 value_address (val), stream, 0,
680 val, &opts, current_language);
682 /* Note: When we look up RTTI entries, we don't get any
683 information on const or volatile attributes. */
685 else if (type != check_typedef (value_enclosing_type (val)))
687 /* No RTTI information, so let's do our best. */
688 fprintf_filtered (stream, "(%s ?) ",
689 TYPE_NAME (value_enclosing_type (val)));
690 val_print (value_enclosing_type (val),
692 value_address (val), stream, 0,
693 val, &opts, current_language);
696 /* Otherwise, we end up at the return outside this "if". */
700 value_embedded_offset (val),
703 val, &opts, current_language);