1 /* Support for printing C values for GDB, the GNU debugger.
3 Copyright (C) 1986-2020 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
.minsym
->print_name (), 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
= msymbol
.minsym
->search_name ();
207 wsym
= lookup_symbol_search_name (search_name
, NULL
,
213 wtype
= SYMBOL_TYPE (wsym
);
217 wtype
= unresolved_elttype
;
219 vt_val
= value_at (wtype
, vt_address
);
220 common_val_print (vt_val
, stream
, recurse
+ 1, options
,
222 if (options
->prettyformat
)
224 fprintf_filtered (stream
, "\n");
225 print_spaces_filtered (2 + 2 * recurse
, stream
);
231 /* c_val_print helper for TYPE_CODE_ARRAY. */
234 c_val_print_array (struct type
*type
, const gdb_byte
*valaddr
,
235 int embedded_offset
, CORE_ADDR address
,
236 struct ui_file
*stream
, int recurse
,
237 struct value
*original_value
,
238 const struct value_print_options
*options
)
240 struct type
*unresolved_elttype
= TYPE_TARGET_TYPE (type
);
241 struct type
*elttype
= check_typedef (unresolved_elttype
);
242 struct gdbarch
*arch
= get_type_arch (type
);
243 int unit_size
= gdbarch_addressable_memory_unit_size (arch
);
245 if (TYPE_LENGTH (type
) > 0 && TYPE_LENGTH (unresolved_elttype
) > 0)
247 LONGEST low_bound
, high_bound
;
249 enum bfd_endian byte_order
= type_byte_order (type
);
251 if (!get_array_bounds (type
, &low_bound
, &high_bound
))
252 error (_("Could not determine the array high bound"));
254 eltlen
= TYPE_LENGTH (elttype
);
255 len
= high_bound
- low_bound
+ 1;
256 if (options
->prettyformat_arrays
)
258 print_spaces_filtered (2 + 2 * recurse
, stream
);
261 /* Print arrays of textual chars with a string syntax, as
262 long as the entire array is valid. */
263 if (c_textual_element_type (unresolved_elttype
,
265 && value_bytes_available (original_value
, embedded_offset
,
267 && !value_bits_any_optimized_out (original_value
,
268 TARGET_CHAR_BIT
* embedded_offset
,
269 TARGET_CHAR_BIT
* TYPE_LENGTH (type
)))
271 int force_ellipses
= 0;
273 /* If requested, look for the first null char and only
274 print elements up to it. */
275 if (options
->stop_print_at_null
)
277 unsigned int temp_len
;
281 && temp_len
< options
->print_max
282 && extract_unsigned_integer (valaddr
283 + embedded_offset
* unit_size
285 eltlen
, byte_order
) != 0);
289 /* Force LA_PRINT_STRING to print ellipses if
290 we've printed the maximum characters and
291 the next character is not \000. */
292 if (temp_len
== options
->print_max
&& temp_len
< len
)
295 = extract_unsigned_integer (valaddr
296 + embedded_offset
* unit_size
306 LA_PRINT_STRING (stream
, unresolved_elttype
,
307 valaddr
+ embedded_offset
* unit_size
, len
,
308 NULL
, force_ellipses
, options
);
313 fprintf_filtered (stream
, "{");
314 /* If this is a virtual function table, print the 0th
315 entry specially, and the rest of the members
317 if (cp_is_vtbl_ptr_type (elttype
))
320 fprintf_filtered (stream
, _("%d vtable entries"),
323 val_print_array_elements (type
, embedded_offset
,
325 recurse
, original_value
, options
, i
);
326 fprintf_filtered (stream
, "}");
331 /* Array of unspecified length: treat like pointer to first elt. */
332 print_unpacked_pointer (type
, elttype
, unresolved_elttype
, valaddr
,
333 embedded_offset
, address
+ embedded_offset
,
334 stream
, recurse
, options
);
338 /* c_val_print helper for TYPE_CODE_PTR. */
341 c_val_print_ptr (struct type
*type
, const gdb_byte
*valaddr
,
342 int embedded_offset
, struct ui_file
*stream
, int recurse
,
343 struct value
*original_value
,
344 const struct value_print_options
*options
)
346 struct gdbarch
*arch
= get_type_arch (type
);
347 int unit_size
= gdbarch_addressable_memory_unit_size (arch
);
349 if (options
->format
&& options
->format
!= 's')
351 val_print_scalar_formatted (type
, embedded_offset
,
352 original_value
, options
, 0, stream
);
354 else if (options
->vtblprint
&& cp_is_vtbl_ptr_type (type
))
356 /* Print the unmangled name if desired. */
357 /* Print vtable entry - we only get here if we ARE using
358 -fvtable_thunks. (Otherwise, look under
359 TYPE_CODE_STRUCT.) */
361 = extract_typed_address (valaddr
+ embedded_offset
, type
);
362 struct gdbarch
*gdbarch
= get_type_arch (type
);
364 print_function_pointer_address (options
, gdbarch
, addr
, stream
);
368 struct type
*unresolved_elttype
= TYPE_TARGET_TYPE (type
);
369 struct type
*elttype
= check_typedef (unresolved_elttype
);
370 CORE_ADDR addr
= unpack_pointer (type
,
371 valaddr
+ embedded_offset
* unit_size
);
373 print_unpacked_pointer (type
, elttype
, unresolved_elttype
, valaddr
,
374 embedded_offset
, addr
, stream
, recurse
, options
);
378 /* c_val_print helper for TYPE_CODE_STRUCT. */
381 c_val_print_struct (struct type
*type
, const gdb_byte
*valaddr
,
382 int embedded_offset
, CORE_ADDR address
,
383 struct ui_file
*stream
, int recurse
,
384 struct value
*original_value
,
385 const struct value_print_options
*options
)
387 if (options
->vtblprint
&& cp_is_vtbl_ptr_type (type
))
389 /* Print the unmangled name if desired. */
390 /* Print vtable entry - we only get here if NOT using
391 -fvtable_thunks. (Otherwise, look under
393 struct gdbarch
*gdbarch
= get_type_arch (type
);
394 int offset
= (embedded_offset
395 + TYPE_FIELD_BITPOS (type
,
396 VTBL_FNADDR_OFFSET
) / 8);
397 struct type
*field_type
= TYPE_FIELD_TYPE (type
, VTBL_FNADDR_OFFSET
);
398 CORE_ADDR addr
= extract_typed_address (valaddr
+ offset
, field_type
);
400 print_function_pointer_address (options
, gdbarch
, addr
, stream
);
403 cp_print_value_fields_rtti (type
, valaddr
,
404 embedded_offset
, address
,
406 original_value
, options
,
410 /* c_val_print helper for TYPE_CODE_UNION. */
413 c_val_print_union (struct type
*type
, const gdb_byte
*valaddr
,
414 int embedded_offset
, CORE_ADDR address
,
415 struct ui_file
*stream
, int recurse
,
416 struct value
*original_value
,
417 const struct value_print_options
*options
)
419 if (recurse
&& !options
->unionprint
)
421 fprintf_filtered (stream
, "{...}");
425 c_val_print_struct (type
, valaddr
, embedded_offset
, address
, stream
,
426 recurse
, original_value
, options
);
430 /* c_val_print helper for TYPE_CODE_INT. */
433 c_val_print_int (struct type
*type
, struct type
*unresolved_type
,
434 const gdb_byte
*valaddr
, int embedded_offset
,
435 struct ui_file
*stream
, struct value
*original_value
,
436 const struct value_print_options
*options
)
438 struct gdbarch
*arch
= get_type_arch (type
);
439 int unit_size
= gdbarch_addressable_memory_unit_size (arch
);
441 if (options
->format
|| options
->output_format
)
443 struct value_print_options opts
= *options
;
445 opts
.format
= (options
->format
? options
->format
446 : options
->output_format
);
447 val_print_scalar_formatted (type
, embedded_offset
,
448 original_value
, &opts
, 0, stream
);
452 val_print_scalar_formatted (type
, embedded_offset
,
453 original_value
, options
, 0, stream
);
454 /* C and C++ has no single byte int type, char is used
455 instead. Since we don't know whether the value is really
456 intended to be used as an integer or a character, print
457 the character equivalent as well. */
458 if (c_textual_element_type (unresolved_type
, options
->format
))
460 fputs_filtered (" ", stream
);
461 LA_PRINT_CHAR (unpack_long (type
,
462 valaddr
+ embedded_offset
* unit_size
),
463 unresolved_type
, stream
);
468 /* c_val_print helper for TYPE_CODE_MEMBERPTR. */
471 c_val_print_memberptr (struct type
*type
, const gdb_byte
*valaddr
,
472 int embedded_offset
, CORE_ADDR address
,
473 struct ui_file
*stream
, int recurse
,
474 struct value
*original_value
,
475 const struct value_print_options
*options
)
477 if (!options
->format
)
479 cp_print_class_member (valaddr
+ embedded_offset
, type
, stream
, "&");
483 generic_val_print (type
, embedded_offset
, address
, stream
,
484 recurse
, original_value
, options
, &c_decorations
);
488 /* See val_print for a description of the various parameters of this
489 function; they are identical. */
492 c_val_print (struct type
*type
,
493 int embedded_offset
, CORE_ADDR address
,
494 struct ui_file
*stream
, int recurse
,
495 struct value
*original_value
,
496 const struct value_print_options
*options
)
498 struct type
*unresolved_type
= type
;
499 const gdb_byte
*valaddr
= value_contents_for_printing (original_value
);
501 type
= check_typedef (type
);
502 switch (TYPE_CODE (type
))
504 case TYPE_CODE_ARRAY
:
505 c_val_print_array (type
, valaddr
, embedded_offset
, address
, stream
,
506 recurse
, original_value
, options
);
509 case TYPE_CODE_METHODPTR
:
510 cplus_print_method_ptr (valaddr
+ embedded_offset
, type
, stream
);
514 c_val_print_ptr (type
, valaddr
, embedded_offset
, stream
, recurse
,
515 original_value
, options
);
518 case TYPE_CODE_UNION
:
519 c_val_print_union (type
, valaddr
, embedded_offset
, address
, stream
,
520 recurse
, original_value
, options
);
523 case TYPE_CODE_STRUCT
:
524 c_val_print_struct (type
, valaddr
, embedded_offset
, address
, stream
,
525 recurse
, original_value
, options
);
529 c_val_print_int (type
, unresolved_type
, valaddr
, embedded_offset
, stream
,
530 original_value
, options
);
533 case TYPE_CODE_MEMBERPTR
:
534 c_val_print_memberptr (type
, valaddr
, embedded_offset
, address
, stream
,
535 recurse
, original_value
, options
);
539 case TYPE_CODE_RVALUE_REF
:
541 case TYPE_CODE_FLAGS
:
543 case TYPE_CODE_METHOD
:
545 case TYPE_CODE_RANGE
:
547 case TYPE_CODE_DECFLOAT
:
549 case TYPE_CODE_ERROR
:
550 case TYPE_CODE_UNDEF
:
551 case TYPE_CODE_COMPLEX
:
554 generic_val_print (type
, embedded_offset
, address
,
555 stream
, recurse
, original_value
, options
,
564 c_value_print_inner (struct value
*val
, struct ui_file
*stream
, int recurse
,
565 const struct value_print_options
*options
)
567 c_val_print (value_type (val
), value_embedded_offset (val
),
568 value_address (val
), stream
, recurse
, val
, options
);
573 c_value_print (struct value
*val
, struct ui_file
*stream
,
574 const struct value_print_options
*options
)
576 struct type
*type
, *real_type
;
579 struct value_print_options opts
= *options
;
583 /* If it is a pointer, indicate what it points to.
585 Print type also if it is a reference.
587 C++: if it is a member pointer, we will take care
588 of that when we print it. */
590 type
= check_typedef (value_type (val
));
592 if (TYPE_CODE (type
) == TYPE_CODE_PTR
|| TYPE_IS_REFERENCE (type
))
594 struct type
*original_type
= value_type (val
);
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 (original_type
) == TYPE_CODE_PTR
601 && TYPE_NAME (original_type
) == NULL
602 && TYPE_NAME (TYPE_TARGET_TYPE (original_type
)) != NULL
603 && (strcmp (TYPE_NAME (TYPE_TARGET_TYPE (original_type
)),
605 || textual_name (TYPE_NAME (TYPE_TARGET_TYPE (original_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. */
632 /* Need to adjust pointer value. */
633 val
= value_from_pointer (real_type
,
634 value_as_address (val
) - top
);
636 /* Note: When we look up RTTI entries, we don't get
637 any information on const or volatile
643 val
= value_ref (value_ind (val
), refcode
);
645 type
= value_type (val
);
646 type_print (type
, "", stream
, -1);
647 fprintf_filtered (stream
, ") ");
652 fprintf_filtered (stream
, "(");
653 type_print (value_type (val
), "", stream
, -1);
654 fprintf_filtered (stream
, ") ");
658 if (!value_initialized (val
))
659 fprintf_filtered (stream
, " [uninitialized] ");
661 if (options
->objectprint
&& (TYPE_CODE (type
) == TYPE_CODE_STRUCT
))
663 /* Attempt to determine real type of object. */
664 real_type
= value_rtti_type (val
, &full
, &top
, &using_enc
);
667 /* We have RTTI information, so use it. */
668 val
= value_full_object (val
, real_type
,
669 full
, top
, using_enc
);
670 /* In a destructor we might see a real type that is a
671 superclass of the object's type. In this case it is
672 better to leave the object as-is. */
674 && (TYPE_LENGTH (real_type
)
675 < TYPE_LENGTH (value_enclosing_type (val
)))))
676 val
= value_cast (real_type
, val
);
677 fprintf_filtered (stream
, "(%s%s) ",
678 TYPE_NAME (real_type
),
679 full
? "" : _(" [incomplete object]"));
681 else if (type
!= check_typedef (value_enclosing_type (val
)))
683 /* No RTTI information, so let's do our best. */
684 fprintf_filtered (stream
, "(%s ?) ",
685 TYPE_NAME (value_enclosing_type (val
)));
686 val
= value_cast (value_enclosing_type (val
), val
);
690 common_val_print (val
, stream
, 0, &opts
, current_language
);