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 /* See val_print for a description of the various parameters of this
374 function; they are identical. */
377 c_val_print (struct type
*type
, const gdb_byte
*valaddr
,
378 int embedded_offset
, CORE_ADDR address
,
379 struct ui_file
*stream
, int recurse
,
380 const struct value
*original_value
,
381 const struct value_print_options
*options
)
383 struct gdbarch
*gdbarch
= get_type_arch (type
);
384 struct type
*unresolved_type
= type
;
386 CHECK_TYPEDEF (type
);
387 switch (TYPE_CODE (type
))
389 case TYPE_CODE_ARRAY
:
390 c_val_print_array (type
, valaddr
, embedded_offset
, address
, stream
,
391 recurse
, original_value
, options
);
394 case TYPE_CODE_METHODPTR
:
395 cplus_print_method_ptr (valaddr
+ embedded_offset
, type
, stream
);
399 c_val_print_ptr (type
, valaddr
, embedded_offset
, stream
, recurse
,
400 original_value
, options
);
403 case TYPE_CODE_UNION
:
404 if (recurse
&& !options
->unionprint
)
406 fprintf_filtered (stream
, "{...}");
410 case TYPE_CODE_STRUCT
:
411 /*FIXME: Abstract this away. */
412 if (options
->vtblprint
&& cp_is_vtbl_ptr_type (type
))
414 /* Print the unmangled name if desired. */
415 /* Print vtable entry - we only get here if NOT using
416 -fvtable_thunks. (Otherwise, look under
418 int offset
= (embedded_offset
419 + TYPE_FIELD_BITPOS (type
,
420 VTBL_FNADDR_OFFSET
) / 8);
421 struct type
*field_type
= TYPE_FIELD_TYPE (type
,
424 = extract_typed_address (valaddr
+ offset
, field_type
);
426 print_function_pointer_address (options
, gdbarch
, addr
, stream
);
429 cp_print_value_fields_rtti (type
, valaddr
,
430 embedded_offset
, address
,
432 original_value
, options
,
437 if (options
->format
|| options
->output_format
)
439 struct value_print_options opts
= *options
;
441 opts
.format
= (options
->format
? options
->format
442 : options
->output_format
);
443 val_print_scalar_formatted (type
, valaddr
, embedded_offset
,
444 original_value
, &opts
, 0, stream
);
448 val_print_type_code_int (type
, valaddr
+ embedded_offset
,
450 /* C and C++ has no single byte int type, char is used
451 instead. Since we don't know whether the value is really
452 intended to be used as an integer or a character, print
453 the character equivalent as well. */
454 if (c_textual_element_type (unresolved_type
, options
->format
))
456 fputs_filtered (" ", stream
);
457 LA_PRINT_CHAR (unpack_long (type
, valaddr
+ embedded_offset
),
458 unresolved_type
, stream
);
463 case TYPE_CODE_MEMBERPTR
:
464 if (!options
->format
)
466 cp_print_class_member (valaddr
+ embedded_offset
, type
, stream
, "&");
473 case TYPE_CODE_FLAGS
:
475 case TYPE_CODE_METHOD
:
477 case TYPE_CODE_RANGE
:
479 case TYPE_CODE_DECFLOAT
:
481 case TYPE_CODE_ERROR
:
482 case TYPE_CODE_UNDEF
:
483 case TYPE_CODE_COMPLEX
:
486 generic_val_print (type
, valaddr
, embedded_offset
, address
,
487 stream
, recurse
, original_value
, options
,
495 c_value_print (struct value
*val
, struct ui_file
*stream
,
496 const struct value_print_options
*options
)
498 struct type
*type
, *real_type
, *val_type
;
499 int full
, top
, using_enc
;
500 struct value_print_options opts
= *options
;
504 /* If it is a pointer, indicate what it points to.
506 Print type also if it is a reference.
508 C++: if it is a member pointer, we will take care
509 of that when we print it. */
511 /* Preserve the original type before stripping typedefs. We prefer
512 to pass down the original type when possible, but for local
513 checks it is better to look past the typedefs. */
514 val_type
= value_type (val
);
515 type
= check_typedef (val_type
);
517 if (TYPE_CODE (type
) == TYPE_CODE_PTR
518 || TYPE_CODE (type
) == TYPE_CODE_REF
)
520 /* Hack: remove (char *) for char strings. Their
521 type is indicated by the quoted string anyway.
522 (Don't use c_textual_element_type here; quoted strings
523 are always exactly (char *), (wchar_t *), or the like. */
524 if (TYPE_CODE (val_type
) == TYPE_CODE_PTR
525 && TYPE_NAME (val_type
) == NULL
526 && TYPE_NAME (TYPE_TARGET_TYPE (val_type
)) != NULL
527 && (strcmp (TYPE_NAME (TYPE_TARGET_TYPE (val_type
)),
529 || textual_name (TYPE_NAME (TYPE_TARGET_TYPE (val_type
)))))
533 else if (options
->objectprint
534 && (TYPE_CODE (TYPE_TARGET_TYPE (type
)) == TYPE_CODE_STRUCT
))
536 int is_ref
= TYPE_CODE (type
) == TYPE_CODE_REF
;
539 val
= value_addr (val
);
541 /* Pointer to class, check real type of object. */
542 fprintf_filtered (stream
, "(");
544 if (value_entirely_available (val
))
546 real_type
= value_rtti_indirect_type (val
, &full
, &top
,
550 /* RTTI entry found. */
553 /* Need to adjust pointer value. */
554 val
= value_from_pointer (real_type
,
555 value_as_address (val
) - top
);
559 val
= value_ref (value_ind (val
));
560 type
= value_type (val
);
563 /* Note: When we look up RTTI entries, we don't get
564 any information on const or volatile
568 type_print (type
, "", stream
, -1);
569 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
) == 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 fprintf_filtered (stream
, "(%s%s) ",
594 TYPE_NAME (real_type
),
595 full
? "" : _(" [incomplete object]"));
596 /* Print out object: enclosing type is same as real_type if
598 val_print (value_enclosing_type (val
),
599 value_contents_for_printing (val
), 0,
600 value_address (val
), stream
, 0,
601 val
, &opts
, current_language
);
603 /* Note: When we look up RTTI entries, we don't get any
604 information on const or volatile attributes. */
606 else if (type
!= check_typedef (value_enclosing_type (val
)))
608 /* No RTTI information, so let's do our best. */
609 fprintf_filtered (stream
, "(%s ?) ",
610 TYPE_NAME (value_enclosing_type (val
)));
611 val_print (value_enclosing_type (val
),
612 value_contents_for_printing (val
), 0,
613 value_address (val
), stream
, 0,
614 val
, &opts
, current_language
);
617 /* Otherwise, we end up at the return outside this "if". */
620 val_print (val_type
, value_contents_for_printing (val
),
621 value_embedded_offset (val
),
624 val
, &opts
, current_language
);