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 (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 (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 (true_type
->code () == 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 (true_type
->code () == 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 (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 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_value_print helper for TYPE_CODE_ARRAY. */
234 c_value_print_array (struct value
*val
,
235 struct ui_file
*stream
, int recurse
,
236 const struct value_print_options
*options
)
238 struct type
*type
= check_typedef (value_type (val
));
239 CORE_ADDR address
= value_address (val
);
240 const gdb_byte
*valaddr
= value_contents_for_printing (val
);
241 struct type
*unresolved_elttype
= TYPE_TARGET_TYPE (type
);
242 struct type
*elttype
= check_typedef (unresolved_elttype
);
244 if (TYPE_LENGTH (type
) > 0 && TYPE_LENGTH (unresolved_elttype
) > 0)
246 LONGEST low_bound
, high_bound
;
248 enum bfd_endian byte_order
= type_byte_order (type
);
250 if (!get_array_bounds (type
, &low_bound
, &high_bound
))
251 error (_("Could not determine the array high bound"));
253 eltlen
= TYPE_LENGTH (elttype
);
254 len
= high_bound
- low_bound
+ 1;
256 /* Print arrays of textual chars with a string syntax, as
257 long as the entire array is valid. */
258 if (c_textual_element_type (unresolved_elttype
,
260 && value_bytes_available (val
, 0, TYPE_LENGTH (type
))
261 && !value_bits_any_optimized_out (val
, 0,
262 TARGET_CHAR_BIT
* TYPE_LENGTH (type
)))
264 int force_ellipses
= 0;
266 /* If requested, look for the first null char and only
267 print elements up to it. */
268 if (options
->stop_print_at_null
)
270 unsigned int temp_len
;
274 && temp_len
< options
->print_max
275 && extract_unsigned_integer (valaddr
+ temp_len
* eltlen
,
276 eltlen
, byte_order
) != 0);
280 /* Force LA_PRINT_STRING to print ellipses if
281 we've printed the maximum characters and
282 the next character is not \000. */
283 if (temp_len
== options
->print_max
&& temp_len
< len
)
286 = extract_unsigned_integer (valaddr
+ temp_len
* eltlen
,
295 LA_PRINT_STRING (stream
, unresolved_elttype
, valaddr
, len
,
296 NULL
, force_ellipses
, options
);
301 fprintf_filtered (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 fprintf_filtered (stream
, _("%d vtable entries"),
311 value_print_array_elements (val
, stream
, recurse
, options
, i
);
312 fprintf_filtered (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 (value_type (val
));
336 struct gdbarch
*arch
= get_type_arch (type
);
337 const gdb_byte
*valaddr
= value_contents_for_printing (val
);
339 if (options
->vtblprint
&& cp_is_vtbl_ptr_type (type
))
341 /* Print the unmangled name if desired. */
342 /* Print vtable entry - we only get here if we ARE using
343 -fvtable_thunks. (Otherwise, look under
344 TYPE_CODE_STRUCT.) */
345 CORE_ADDR addr
= extract_typed_address (valaddr
, type
);
347 print_function_pointer_address (options
, arch
, addr
, stream
);
351 struct type
*unresolved_elttype
= TYPE_TARGET_TYPE (type
);
352 struct type
*elttype
= check_typedef (unresolved_elttype
);
353 CORE_ADDR addr
= unpack_pointer (type
, valaddr
);
355 print_unpacked_pointer (type
, elttype
, unresolved_elttype
, valaddr
,
356 0, addr
, stream
, recurse
, options
);
360 /* c_value_print helper for TYPE_CODE_STRUCT and TYPE_CODE_UNION. */
363 c_value_print_struct (struct value
*val
, struct ui_file
*stream
, int recurse
,
364 const struct value_print_options
*options
)
366 struct type
*type
= check_typedef (value_type (val
));
368 if (type
->code () == TYPE_CODE_UNION
&& recurse
&& !options
->unionprint
)
369 fprintf_filtered (stream
, "{...}");
370 else if (options
->vtblprint
&& cp_is_vtbl_ptr_type (type
))
372 /* Print the unmangled name if desired. */
373 /* Print vtable entry - we only get here if NOT using
374 -fvtable_thunks. (Otherwise, look under
376 struct gdbarch
*gdbarch
= get_type_arch (type
);
377 int offset
= TYPE_FIELD_BITPOS (type
, VTBL_FNADDR_OFFSET
) / 8;
378 struct type
*field_type
= type
->field (VTBL_FNADDR_OFFSET
).type ();
379 const gdb_byte
*valaddr
= value_contents_for_printing (val
);
380 CORE_ADDR addr
= extract_typed_address (valaddr
+ offset
, field_type
);
382 print_function_pointer_address (options
, gdbarch
, addr
, stream
);
385 cp_print_value_fields (val
, stream
, recurse
, options
, NULL
, 0);
388 /* c_value_print helper for TYPE_CODE_INT. */
391 c_value_print_int (struct value
*val
, struct ui_file
*stream
,
392 const struct value_print_options
*options
)
394 if (options
->format
|| options
->output_format
)
396 struct value_print_options opts
= *options
;
398 opts
.format
= (options
->format
? options
->format
399 : options
->output_format
);
400 value_print_scalar_formatted (val
, &opts
, 0, stream
);
404 value_print_scalar_formatted (val
, options
, 0, stream
);
405 /* C and C++ has no single byte int type, char is used
406 instead. Since we don't know whether the value is really
407 intended to be used as an integer or a character, print
408 the character equivalent as well. */
409 struct type
*type
= value_type (val
);
410 const gdb_byte
*valaddr
= value_contents_for_printing (val
);
411 if (c_textual_element_type (type
, options
->format
))
413 fputs_filtered (" ", stream
);
414 LA_PRINT_CHAR (unpack_long (type
, valaddr
), type
, stream
);
419 /* c_value_print helper for TYPE_CODE_MEMBERPTR. */
422 c_value_print_memberptr (struct value
*val
, struct ui_file
*stream
,
424 const struct value_print_options
*options
)
426 if (!options
->format
)
428 struct type
*type
= check_typedef (value_type (val
));
429 const gdb_byte
*valaddr
= value_contents_for_printing (val
);
430 cp_print_class_member (valaddr
, type
, stream
, "&");
433 generic_value_print (val
, stream
, recurse
, options
, &c_decorations
);
439 c_value_print_inner (struct value
*val
, struct ui_file
*stream
, int recurse
,
440 const struct value_print_options
*options
)
442 struct type
*type
= value_type (val
);
443 const gdb_byte
*valaddr
= value_contents_for_printing (val
);
445 type
= check_typedef (type
);
446 switch (type
->code ())
448 case TYPE_CODE_ARRAY
:
449 c_value_print_array (val
, stream
, recurse
, options
);
452 case TYPE_CODE_METHODPTR
:
453 cplus_print_method_ptr (valaddr
, type
, stream
);
457 c_value_print_ptr (val
, stream
, recurse
, options
);
460 case TYPE_CODE_UNION
:
461 case TYPE_CODE_STRUCT
:
462 c_value_print_struct (val
, stream
, recurse
, options
);
466 c_value_print_int (val
, stream
, options
);
469 case TYPE_CODE_MEMBERPTR
:
470 c_value_print_memberptr (val
, stream
, recurse
, options
);
474 case TYPE_CODE_RVALUE_REF
:
476 case TYPE_CODE_FLAGS
:
478 case TYPE_CODE_METHOD
:
480 case TYPE_CODE_RANGE
:
482 case TYPE_CODE_DECFLOAT
:
484 case TYPE_CODE_ERROR
:
485 case TYPE_CODE_UNDEF
:
486 case TYPE_CODE_COMPLEX
:
489 generic_value_print (val
, stream
, recurse
, options
, &c_decorations
);
496 c_value_print (struct value
*val
, struct ui_file
*stream
,
497 const struct value_print_options
*options
)
499 struct type
*type
, *real_type
;
502 struct value_print_options opts
= *options
;
506 /* If it is a pointer, indicate what it points to.
508 Print type also if it is a reference.
510 C++: if it is a member pointer, we will take care
511 of that when we print it. */
513 type
= check_typedef (value_type (val
));
515 if (type
->code () == TYPE_CODE_PTR
|| TYPE_IS_REFERENCE (type
))
517 struct type
*original_type
= value_type (val
);
519 /* Hack: remove (char *) for char strings. Their
520 type is indicated by the quoted string anyway.
521 (Don't use c_textual_element_type here; quoted strings
522 are always exactly (char *), (wchar_t *), or the like. */
523 if (original_type
->code () == TYPE_CODE_PTR
524 && original_type
->name () == NULL
525 && TYPE_TARGET_TYPE (original_type
)->name () != NULL
526 && (strcmp (TYPE_TARGET_TYPE (original_type
)->name (),
528 || textual_name (TYPE_TARGET_TYPE (original_type
)->name ())))
532 else if (options
->objectprint
533 && (TYPE_TARGET_TYPE (type
)->code () == TYPE_CODE_STRUCT
))
535 int is_ref
= TYPE_IS_REFERENCE (type
);
536 enum type_code refcode
= TYPE_CODE_UNDEF
;
540 val
= value_addr (val
);
541 refcode
= type
->code ();
544 /* Pointer to class, check real type of object. */
545 fprintf_filtered (stream
, "(");
547 if (value_entirely_available (val
))
549 real_type
= value_rtti_indirect_type (val
, &full
, &top
,
553 /* RTTI entry found. */
555 /* Need to adjust pointer value. */
556 val
= value_from_pointer (real_type
,
557 value_as_address (val
) - top
);
559 /* Note: When we look up RTTI entries, we don't get
560 any information on const or volatile
566 val
= value_ref (value_ind (val
), refcode
);
568 type
= value_type (val
);
569 type_print (type
, "", stream
, -1);
570 fprintf_filtered (stream
, ") ");
575 fprintf_filtered (stream
, "(");
576 type_print (value_type (val
), "", stream
, -1);
577 fprintf_filtered (stream
, ") ");
581 if (!value_initialized (val
))
582 fprintf_filtered (stream
, " [uninitialized] ");
584 if (options
->objectprint
&& (type
->code () == TYPE_CODE_STRUCT
))
586 /* Attempt to determine real type of object. */
587 real_type
= value_rtti_type (val
, &full
, &top
, &using_enc
);
590 /* We have RTTI information, so use it. */
591 val
= value_full_object (val
, real_type
,
592 full
, top
, using_enc
);
593 /* In a destructor we might see a real type that is a
594 superclass of the object's type. In this case it is
595 better to leave the object as-is. */
597 && (TYPE_LENGTH (real_type
)
598 < TYPE_LENGTH (value_enclosing_type (val
)))))
599 val
= value_cast (real_type
, val
);
600 fprintf_filtered (stream
, "(%s%s) ",
602 full
? "" : _(" [incomplete object]"));
604 else if (type
!= check_typedef (value_enclosing_type (val
)))
606 /* No RTTI information, so let's do our best. */
607 fprintf_filtered (stream
, "(%s ?) ",
608 value_enclosing_type (val
)->name ());
609 val
= value_cast (value_enclosing_type (val
), val
);
613 common_val_print (val
, stream
, 0, &opts
, current_language
);