1 /* Support for printing C values for GDB, the GNU debugger.
3 Copyright (C) 1986-2024 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/>. */
20 #include "extract-store-integer.h"
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 (true_type
->code () == TYPE_CODE_CHAR
)
72 /* Any other character-like types must be integral. */
73 if (true_type
->code () != TYPE_CODE_INT
)
76 /* We peel typedefs one by one, looking for a match. */
80 /* Check the name of the type. */
81 if (iter_type
->name () && textual_name (iter_type
->name ()))
84 if (iter_type
->code () != 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 (iter_type
->target_type ())
91 iter_type
= iter_type
->target_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 (true_type
->code () == TYPE_CODE_INT
101 && true_type
->length () == 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 (true_type
->code () == TYPE_CODE_INT
110 && true_type
->length () == 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
= type
->arch ();
149 if (elttype
->code () == 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 gdb_puts (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 gdb_puts (" ", 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 bound_minimal_symbol msymbol
= lookup_minimal_symbol_by_pc (vt_address
);
181 /* If 'symbol_print' is set, we did the work above. */
182 if (!options
->symbol_print
183 && (msymbol
.minsym
!= NULL
)
184 && (vt_address
== msymbol
.value_address ()))
187 gdb_puts (" ", stream
);
188 gdb_puts (" <", stream
);
189 gdb_puts (msymbol
.minsym
->print_name (), stream
);
190 gdb_puts (">", stream
);
194 if (vt_address
&& options
->vtblprint
)
196 struct value
*vt_val
;
197 struct symbol
*wsym
= NULL
;
201 gdb_puts (" ", stream
);
203 if (msymbol
.minsym
!= NULL
)
205 const char *search_name
= msymbol
.minsym
->search_name ();
206 wsym
= lookup_symbol_search_name (search_name
, NULL
,
207 SEARCH_VAR_DOMAIN
).symbol
;
212 wtype
= wsym
->type ();
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 gdb_printf (stream
, "\n");
224 print_spaces (2 + 2 * recurse
, stream
);
230 /* c_value_print helper for TYPE_CODE_ARRAY. */
233 c_value_print_array (struct value
*val
,
234 struct ui_file
*stream
, int recurse
,
235 const struct value_print_options
*options
)
237 struct type
*type
= check_typedef (val
->type ());
238 CORE_ADDR address
= val
->address ();
239 const gdb_byte
*valaddr
= val
->contents_for_printing ().data ();
240 struct type
*unresolved_elttype
= type
->target_type ();
241 struct type
*elttype
= check_typedef (unresolved_elttype
);
243 if (type
->length () > 0 && unresolved_elttype
->length () > 0)
245 LONGEST low_bound
, high_bound
;
247 enum bfd_endian byte_order
= type_byte_order (type
);
249 if (!get_array_bounds (type
, &low_bound
, &high_bound
))
250 error (_("Could not determine the array high bound"));
252 eltlen
= elttype
->length ();
253 len
= high_bound
- low_bound
+ 1;
255 /* Print arrays of textual chars with a string syntax, as
256 long as the entire array is valid. */
257 if (c_textual_element_type (unresolved_elttype
,
259 && val
->bytes_available (0, type
->length ())
260 && !val
->bits_any_optimized_out (0,
261 TARGET_CHAR_BIT
* type
->length ()))
263 int force_ellipses
= 0;
265 /* If requested, look for the first null char and only
266 print elements up to it. */
267 if (options
->stop_print_at_null
)
269 unsigned int print_max_chars
= get_print_max_chars (options
);
270 unsigned int temp_len
;
274 && temp_len
< print_max_chars
275 && extract_unsigned_integer (valaddr
+ temp_len
* eltlen
,
276 eltlen
, byte_order
) != 0);
280 /* Force printstr to print ellipses if
281 we've printed the maximum characters and
282 the next character is not \000. */
283 if (temp_len
== print_max_chars
&& temp_len
< len
)
286 = extract_unsigned_integer (valaddr
+ temp_len
* eltlen
,
295 current_language
->printstr (stream
, unresolved_elttype
, valaddr
, len
,
296 NULL
, force_ellipses
, options
);
301 gdb_printf (stream
, "{");
302 /* If this is a virtual function table, print the 0th
303 entry specially, and the rest of the members
305 if (cp_is_vtbl_ptr_type (elttype
))
308 gdb_printf (stream
, _("%d vtable entries"),
311 value_print_array_elements (val
, stream
, recurse
, options
, i
);
312 gdb_printf (stream
, "}");
317 /* Array of unspecified length: treat like pointer to first elt. */
318 print_unpacked_pointer (type
, elttype
, unresolved_elttype
, valaddr
,
319 0, address
, stream
, recurse
, options
);
323 /* c_value_print_inner helper for TYPE_CODE_PTR. */
326 c_value_print_ptr (struct value
*val
, struct ui_file
*stream
, int recurse
,
327 const struct value_print_options
*options
)
329 if (options
->format
&& options
->format
!= 's')
331 value_print_scalar_formatted (val
, options
, 0, stream
);
335 struct type
*type
= check_typedef (val
->type ());
336 const gdb_byte
*valaddr
= val
->contents_for_printing ().data ();
338 if (options
->vtblprint
&& cp_is_vtbl_ptr_type (type
))
340 /* Print the unmangled name if desired. */
341 /* Print vtable entry - we only get here if we ARE using
342 -fvtable_thunks. (Otherwise, look under
343 TYPE_CODE_STRUCT.) */
344 CORE_ADDR addr
= extract_typed_address (valaddr
, type
);
346 print_function_pointer_address (options
, type
->arch (), addr
, stream
);
350 struct type
*unresolved_elttype
= type
->target_type ();
351 struct type
*elttype
= check_typedef (unresolved_elttype
);
352 CORE_ADDR addr
= unpack_pointer (type
, valaddr
);
354 print_unpacked_pointer (type
, elttype
, unresolved_elttype
, valaddr
,
355 0, addr
, stream
, recurse
, options
);
359 /* c_value_print helper for TYPE_CODE_STRUCT and TYPE_CODE_UNION. */
362 c_value_print_struct (struct value
*val
, struct ui_file
*stream
, int recurse
,
363 const struct value_print_options
*options
)
365 struct type
*type
= check_typedef (val
->type ());
367 if (type
->code () == TYPE_CODE_UNION
&& recurse
&& !options
->unionprint
)
368 gdb_printf (stream
, "{...}");
369 else if (options
->vtblprint
&& cp_is_vtbl_ptr_type (type
))
371 /* Print the unmangled name if desired. */
372 /* Print vtable entry - we only get here if NOT using
373 -fvtable_thunks. (Otherwise, look under
375 int offset
= type
->field (VTBL_FNADDR_OFFSET
).loc_bitpos () / 8;
376 struct type
*field_type
= type
->field (VTBL_FNADDR_OFFSET
).type ();
377 const gdb_byte
*valaddr
= val
->contents_for_printing ().data ();
378 CORE_ADDR addr
= extract_typed_address (valaddr
+ offset
, field_type
);
380 print_function_pointer_address (options
, type
->arch (), addr
, stream
);
383 cp_print_value_fields (val
, stream
, recurse
, options
, NULL
, 0);
386 /* c_value_print helper for TYPE_CODE_INT. */
389 c_value_print_int (struct value
*val
, struct ui_file
*stream
,
390 const struct value_print_options
*options
)
392 if (options
->format
|| options
->output_format
)
394 struct value_print_options opts
= *options
;
396 opts
.format
= (options
->format
? options
->format
397 : options
->output_format
);
398 value_print_scalar_formatted (val
, &opts
, 0, stream
);
402 value_print_scalar_formatted (val
, options
, 0, stream
);
403 /* C and C++ has no single byte int type, char is used
404 instead. Since we don't know whether the value is really
405 intended to be used as an integer or a character, print
406 the character equivalent as well. */
407 struct type
*type
= val
->type ();
408 const gdb_byte
*valaddr
= val
->contents_for_printing ().data ();
409 if (c_textual_element_type (type
, options
->format
))
411 gdb_puts (" ", stream
);
412 current_language
->printchar (unpack_long (type
, valaddr
), type
,
421 c_value_print_inner (struct value
*val
, struct ui_file
*stream
, int recurse
,
422 const struct value_print_options
*options
)
424 struct type
*type
= val
->type ();
426 type
= check_typedef (type
);
427 switch (type
->code ())
429 case TYPE_CODE_ARRAY
:
430 c_value_print_array (val
, stream
, recurse
, options
);
434 c_value_print_ptr (val
, stream
, recurse
, options
);
437 case TYPE_CODE_UNION
:
438 case TYPE_CODE_STRUCT
:
439 c_value_print_struct (val
, stream
, recurse
, options
);
444 c_value_print_int (val
, stream
, options
);
447 case TYPE_CODE_METHODPTR
:
448 case TYPE_CODE_MEMBERPTR
:
450 case TYPE_CODE_RVALUE_REF
:
452 case TYPE_CODE_FLAGS
:
454 case TYPE_CODE_METHOD
:
456 case TYPE_CODE_RANGE
:
458 case TYPE_CODE_DECFLOAT
:
460 case TYPE_CODE_ERROR
:
461 case TYPE_CODE_UNDEF
:
462 case TYPE_CODE_COMPLEX
:
464 generic_value_print (val
, stream
, recurse
, options
, &c_decorations
);
471 c_value_print (struct value
*val
, struct ui_file
*stream
,
472 const struct value_print_options
*options
)
474 struct type
*type
, *real_type
;
477 struct value_print_options opts
= *options
;
479 opts
.deref_ref
= true;
481 /* If it is a pointer, indicate what it points to.
483 Print type also if it is a reference.
485 C++: if it is a member pointer, we will take care
486 of that when we print it. */
488 type
= check_typedef (val
->type ());
490 if (type
->is_pointer_or_reference ())
492 struct type
*original_type
= val
->type ();
494 /* Hack: remove (char *) for char strings. Their
495 type is indicated by the quoted string anyway.
496 (Don't use c_textual_element_type here; quoted strings
497 are always exactly (char *), (wchar_t *), or the like. */
498 if (original_type
->code () == TYPE_CODE_PTR
499 && original_type
->name () == NULL
500 && original_type
->target_type ()->name () != NULL
501 && (strcmp (original_type
->target_type ()->name (),
503 || textual_name (original_type
->target_type ()->name ())))
507 else if (options
->objectprint
508 && (type
->target_type ()->code () == TYPE_CODE_STRUCT
))
510 int is_ref
= TYPE_IS_REFERENCE (type
);
511 enum type_code refcode
= TYPE_CODE_UNDEF
;
515 val
= value_addr (val
);
516 refcode
= type
->code ();
519 /* Pointer to class, check real type of object. */
520 gdb_printf (stream
, "(");
522 if (val
->entirely_available ())
524 real_type
= value_rtti_indirect_type (val
, &full
, &top
,
528 /* RTTI entry found. */
530 /* Need to adjust pointer value. */
531 val
= value_from_pointer (real_type
,
532 value_as_address (val
) - top
);
534 /* Note: When we look up RTTI entries, we don't get
535 any information on const or volatile
541 val
= value_ref (value_ind (val
), refcode
);
544 type_print (type
, "", stream
, -1);
545 gdb_printf (stream
, ") ");
550 gdb_printf (stream
, "(");
551 type_print (val
->type (), "", stream
, -1);
552 gdb_printf (stream
, ") ");
556 if (!val
->initialized ())
557 gdb_printf (stream
, " [uninitialized] ");
559 if (options
->objectprint
&& (type
->code () == TYPE_CODE_STRUCT
))
561 /* Attempt to determine real type of object. */
562 real_type
= value_rtti_type (val
, &full
, &top
, &using_enc
);
565 /* We have RTTI information, so use it. */
566 val
= value_full_object (val
, real_type
,
567 full
, top
, using_enc
);
568 /* In a destructor we might see a real type that is a
569 superclass of the object's type. In this case it is
570 better to leave the object as-is. */
572 && (real_type
->length ()
573 < val
->enclosing_type ()->length ())))
574 val
= value_cast (real_type
, val
);
575 gdb_printf (stream
, "(%s%s) ",
577 full
? "" : _(" [incomplete object]"));
579 else if (type
!= check_typedef (val
->enclosing_type ()))
581 /* No RTTI information, so let's do our best. */
582 gdb_printf (stream
, "(%s ?) ",
583 val
->enclosing_type ()->name ());
584 val
= value_cast (val
->enclosing_type (), val
);
588 common_val_print (val
, stream
, 0, &opts
, current_language
);