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
= (struct symbol
*) NULL
;
198 struct block
*block
= (struct 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
);
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
);
240 if (TYPE_LENGTH (type
) > 0 && TYPE_LENGTH (unresolved_elttype
) > 0)
242 LONGEST low_bound
, high_bound
;
244 struct gdbarch
*gdbarch
= get_type_arch (type
);
245 enum bfd_endian byte_order
= gdbarch_byte_order (gdbarch
);
246 unsigned int i
= 0; /* Number of characters printed. */
248 if (!get_array_bounds (type
, &low_bound
, &high_bound
))
249 error (_("Could not determine the array high bound"));
251 eltlen
= TYPE_LENGTH (elttype
);
252 len
= high_bound
- low_bound
+ 1;
253 if (options
->prettyformat_arrays
)
255 print_spaces_filtered (2 + 2 * recurse
, stream
);
258 /* Print arrays of textual chars with a string syntax, as
259 long as the entire array is valid. */
260 if (c_textual_element_type (unresolved_elttype
,
262 && value_bytes_available (original_value
, embedded_offset
,
264 && !value_bits_any_optimized_out (original_value
,
265 TARGET_CHAR_BIT
* embedded_offset
,
266 TARGET_CHAR_BIT
* TYPE_LENGTH (type
)))
268 int force_ellipses
= 0;
270 /* If requested, look for the first null char and only
271 print elements up to it. */
272 if (options
->stop_print_at_null
)
274 unsigned int temp_len
;
278 && temp_len
< options
->print_max
279 && extract_unsigned_integer (valaddr
+ embedded_offset
281 eltlen
, byte_order
) != 0);
285 /* Force LA_PRINT_STRING to print ellipses if
286 we've printed the maximum characters and
287 the next character is not \000. */
288 if (temp_len
== options
->print_max
&& temp_len
< len
)
291 = extract_unsigned_integer (valaddr
+ embedded_offset
301 LA_PRINT_STRING (stream
, unresolved_elttype
,
302 valaddr
+ embedded_offset
, len
,
303 NULL
, force_ellipses
, options
);
308 fprintf_filtered (stream
, "{");
309 /* If this is a virtual function table, print the 0th
310 entry specially, and the rest of the members
312 if (cp_is_vtbl_ptr_type (elttype
))
315 fprintf_filtered (stream
, _("%d vtable entries"),
322 val_print_array_elements (type
, valaddr
, embedded_offset
,
324 recurse
, original_value
, options
, i
);
325 fprintf_filtered (stream
, "}");
330 /* Array of unspecified length: treat like pointer to first elt. */
331 print_unpacked_pointer (type
, elttype
, unresolved_elttype
, valaddr
,
332 embedded_offset
, address
+ embedded_offset
,
333 stream
, recurse
, options
);
337 /* c_val_print helper for TYPE_CODE_PTR. */
340 c_val_print_ptr (struct type
*type
, const gdb_byte
*valaddr
,
341 int embedded_offset
, struct ui_file
*stream
, int recurse
,
342 const struct value
*original_value
,
343 const struct value_print_options
*options
)
345 if (options
->format
&& options
->format
!= 's')
347 val_print_scalar_formatted (type
, valaddr
, embedded_offset
,
348 original_value
, options
, 0, stream
);
350 else if (options
->vtblprint
&& cp_is_vtbl_ptr_type (type
))
352 /* Print the unmangled name if desired. */
353 /* Print vtable entry - we only get here if we ARE using
354 -fvtable_thunks. (Otherwise, look under
355 TYPE_CODE_STRUCT.) */
357 = extract_typed_address (valaddr
+ embedded_offset
, type
);
358 struct gdbarch
*gdbarch
= get_type_arch (type
);
360 print_function_pointer_address (options
, gdbarch
, addr
, stream
);
364 struct type
*unresolved_elttype
= TYPE_TARGET_TYPE (type
);
365 struct type
*elttype
= check_typedef (unresolved_elttype
);
366 CORE_ADDR addr
= unpack_pointer (type
, valaddr
+ embedded_offset
);
368 print_unpacked_pointer (type
, elttype
, unresolved_elttype
, valaddr
,
369 embedded_offset
, addr
, stream
, recurse
, options
);
373 /* c_val_print helper for TYPE_CODE_STRUCT. */
376 c_val_print_struct (struct type
*type
, const gdb_byte
*valaddr
,
377 int embedded_offset
, CORE_ADDR address
,
378 struct ui_file
*stream
, int recurse
,
379 const struct value
*original_value
,
380 const struct value_print_options
*options
)
382 if (options
->vtblprint
&& cp_is_vtbl_ptr_type (type
))
384 /* Print the unmangled name if desired. */
385 /* Print vtable entry - we only get here if NOT using
386 -fvtable_thunks. (Otherwise, look under
388 struct gdbarch
*gdbarch
= get_type_arch (type
);
389 int offset
= (embedded_offset
390 + TYPE_FIELD_BITPOS (type
,
391 VTBL_FNADDR_OFFSET
) / 8);
392 struct type
*field_type
= TYPE_FIELD_TYPE (type
, VTBL_FNADDR_OFFSET
);
393 CORE_ADDR addr
= extract_typed_address (valaddr
+ offset
, field_type
);
395 print_function_pointer_address (options
, gdbarch
, addr
, stream
);
398 cp_print_value_fields_rtti (type
, valaddr
,
399 embedded_offset
, address
,
401 original_value
, options
,
405 /* c_val_print helper for TYPE_CODE_UNION. */
408 c_val_print_union (struct type
*type
, const gdb_byte
*valaddr
,
409 int embedded_offset
, CORE_ADDR address
,
410 struct ui_file
*stream
, int recurse
,
411 const struct value
*original_value
,
412 const struct value_print_options
*options
)
414 if (recurse
&& !options
->unionprint
)
416 fprintf_filtered (stream
, "{...}");
420 c_val_print_struct (type
, valaddr
, embedded_offset
, address
, stream
,
421 recurse
, original_value
, options
);
425 /* c_val_print helper for TYPE_CODE_INT. */
428 c_val_print_int (struct type
*type
, struct type
*unresolved_type
,
429 const gdb_byte
*valaddr
, int embedded_offset
,
430 struct ui_file
*stream
, const struct value
*original_value
,
431 const struct value_print_options
*options
)
433 if (options
->format
|| options
->output_format
)
435 struct value_print_options opts
= *options
;
437 opts
.format
= (options
->format
? options
->format
438 : options
->output_format
);
439 val_print_scalar_formatted (type
, valaddr
, embedded_offset
,
440 original_value
, &opts
, 0, stream
);
444 val_print_type_code_int (type
, valaddr
+ embedded_offset
,
446 /* C and C++ has no single byte int type, char is used
447 instead. Since we don't know whether the value is really
448 intended to be used as an integer or a character, print
449 the character equivalent as well. */
450 if (c_textual_element_type (unresolved_type
, options
->format
))
452 fputs_filtered (" ", stream
);
453 LA_PRINT_CHAR (unpack_long (type
, valaddr
+ embedded_offset
),
454 unresolved_type
, stream
);
459 /* c_val_print helper for TYPE_CODE_MEMBERPTR. */
462 c_val_print_memberptr (struct type
*type
, const gdb_byte
*valaddr
,
463 int embedded_offset
, CORE_ADDR address
,
464 struct ui_file
*stream
, int recurse
,
465 const struct value
*original_value
,
466 const struct value_print_options
*options
)
468 if (!options
->format
)
470 cp_print_class_member (valaddr
+ embedded_offset
, type
, stream
, "&");
474 generic_val_print (type
, valaddr
, embedded_offset
, address
, stream
,
475 recurse
, original_value
, options
, &c_decorations
);
479 /* See val_print for a description of the various parameters of this
480 function; they are identical. */
483 c_val_print (struct type
*type
, const gdb_byte
*valaddr
,
484 int embedded_offset
, CORE_ADDR address
,
485 struct ui_file
*stream
, int recurse
,
486 const struct value
*original_value
,
487 const struct value_print_options
*options
)
489 struct type
*unresolved_type
= type
;
491 type
= check_typedef (type
);
492 switch (TYPE_CODE (type
))
494 case TYPE_CODE_ARRAY
:
495 c_val_print_array (type
, valaddr
, embedded_offset
, address
, stream
,
496 recurse
, original_value
, options
);
499 case TYPE_CODE_METHODPTR
:
500 cplus_print_method_ptr (valaddr
+ embedded_offset
, type
, stream
);
504 c_val_print_ptr (type
, valaddr
, embedded_offset
, stream
, recurse
,
505 original_value
, options
);
508 case TYPE_CODE_UNION
:
509 c_val_print_union (type
, valaddr
, embedded_offset
, address
, stream
,
510 recurse
, original_value
, options
);
513 case TYPE_CODE_STRUCT
:
514 c_val_print_struct (type
, valaddr
, embedded_offset
, address
, stream
,
515 recurse
, original_value
, options
);
519 c_val_print_int (type
, unresolved_type
, valaddr
, embedded_offset
, stream
,
520 original_value
, options
);
523 case TYPE_CODE_MEMBERPTR
:
524 c_val_print_memberptr (type
, valaddr
, embedded_offset
, address
, stream
,
525 recurse
, original_value
, options
);
530 case TYPE_CODE_FLAGS
:
532 case TYPE_CODE_METHOD
:
534 case TYPE_CODE_RANGE
:
536 case TYPE_CODE_DECFLOAT
:
538 case TYPE_CODE_ERROR
:
539 case TYPE_CODE_UNDEF
:
540 case TYPE_CODE_COMPLEX
:
543 generic_val_print (type
, valaddr
, embedded_offset
, address
,
544 stream
, recurse
, original_value
, options
,
552 c_value_print (struct value
*val
, struct ui_file
*stream
,
553 const struct value_print_options
*options
)
555 struct type
*type
, *real_type
, *val_type
;
556 int full
, top
, using_enc
;
557 struct value_print_options opts
= *options
;
561 /* If it is a pointer, indicate what it points to.
563 Print type also if it is a reference.
565 C++: if it is a member pointer, we will take care
566 of that when we print it. */
568 /* Preserve the original type before stripping typedefs. We prefer
569 to pass down the original type when possible, but for local
570 checks it is better to look past the typedefs. */
571 val_type
= value_type (val
);
572 type
= check_typedef (val_type
);
574 if (TYPE_CODE (type
) == TYPE_CODE_PTR
575 || TYPE_CODE (type
) == TYPE_CODE_REF
)
577 /* Hack: remove (char *) for char strings. Their
578 type is indicated by the quoted string anyway.
579 (Don't use c_textual_element_type here; quoted strings
580 are always exactly (char *), (wchar_t *), or the like. */
581 if (TYPE_CODE (val_type
) == TYPE_CODE_PTR
582 && TYPE_NAME (val_type
) == NULL
583 && TYPE_NAME (TYPE_TARGET_TYPE (val_type
)) != NULL
584 && (strcmp (TYPE_NAME (TYPE_TARGET_TYPE (val_type
)),
586 || textual_name (TYPE_NAME (TYPE_TARGET_TYPE (val_type
)))))
590 else if (options
->objectprint
591 && (TYPE_CODE (TYPE_TARGET_TYPE (type
)) == TYPE_CODE_STRUCT
))
593 int is_ref
= TYPE_CODE (type
) == TYPE_CODE_REF
;
596 val
= value_addr (val
);
598 /* Pointer to class, check real type of object. */
599 fprintf_filtered (stream
, "(");
601 if (value_entirely_available (val
))
603 real_type
= value_rtti_indirect_type (val
, &full
, &top
,
607 /* RTTI entry found. */
610 /* Need to adjust pointer value. */
611 val
= value_from_pointer (real_type
,
612 value_as_address (val
) - top
);
616 val
= value_ref (value_ind (val
));
617 type
= value_type (val
);
620 /* Note: When we look up RTTI entries, we don't get
621 any information on const or volatile
625 type_print (type
, "", stream
, -1);
626 fprintf_filtered (stream
, ") ");
632 fprintf_filtered (stream
, "(");
633 type_print (value_type (val
), "", stream
, -1);
634 fprintf_filtered (stream
, ") ");
638 if (!value_initialized (val
))
639 fprintf_filtered (stream
, " [uninitialized] ");
641 if (options
->objectprint
&& (TYPE_CODE (type
) == TYPE_CODE_STRUCT
))
643 /* Attempt to determine real type of object. */
644 real_type
= value_rtti_type (val
, &full
, &top
, &using_enc
);
647 /* We have RTTI information, so use it. */
648 val
= value_full_object (val
, real_type
,
649 full
, top
, using_enc
);
650 fprintf_filtered (stream
, "(%s%s) ",
651 TYPE_NAME (real_type
),
652 full
? "" : _(" [incomplete object]"));
653 /* Print out object: enclosing type is same as real_type if
655 val_print (value_enclosing_type (val
),
656 value_contents_for_printing (val
), 0,
657 value_address (val
), stream
, 0,
658 val
, &opts
, current_language
);
660 /* Note: When we look up RTTI entries, we don't get any
661 information on const or volatile attributes. */
663 else if (type
!= check_typedef (value_enclosing_type (val
)))
665 /* No RTTI information, so let's do our best. */
666 fprintf_filtered (stream
, "(%s ?) ",
667 TYPE_NAME (value_enclosing_type (val
)));
668 val_print (value_enclosing_type (val
),
669 value_contents_for_printing (val
), 0,
670 value_address (val
), stream
, 0,
671 val
, &opts
, current_language
);
674 /* Otherwise, we end up at the return outside this "if". */
677 val_print (val_type
, value_contents_for_printing (val
),
678 value_embedded_offset (val
),
681 val
, &opts
, current_language
);