1 /* Support for printing C values for GDB, the GNU debugger.
3 Copyright (C) 1986, 1988, 1989, 1991, 1992, 1993, 1994, 1995, 1996, 1997,
4 1998, 1999, 2000, 2001, 2003, 2005, 2006, 2007, 2008, 2009, 2010, 2011
5 Free Software Foundation, Inc.
7 This file is part of GDB.
9 This program is free software; you can redistribute it and/or modify
10 it under the terms of the GNU General Public License as published by
11 the Free Software Foundation; either version 3 of the License, or
12 (at your option) any later version.
14 This program is distributed in the hope that it will be useful,
15 but WITHOUT ANY WARRANTY; without even the implied warranty of
16 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 GNU General Public License for more details.
19 You should have received a copy of the GNU General Public License
20 along with this program. If not, see <http://www.gnu.org/licenses/>. */
23 #include "gdb_string.h"
26 #include "expression.h"
35 /* Print function pointer with inferior address ADDRESS onto stdio
39 print_function_pointer_address (struct gdbarch *gdbarch,
41 struct ui_file *stream,
45 = gdbarch_convert_from_func_ptr_addr (gdbarch, address,
48 /* If the function pointer is represented by a description, print
49 the address of the description. */
50 if (addressprint && func_addr != address)
52 fputs_filtered ("@", stream);
53 fputs_filtered (paddress (gdbarch, address), stream);
54 fputs_filtered (": ", stream);
56 print_address_demangle (gdbarch, func_addr, stream, demangle);
60 /* A helper for c_textual_element_type. This checks the name of the
61 typedef. This is bogus but it isn't apparent that the compiler
62 provides us the help we may need. */
65 textual_name (const char *name)
67 return (!strcmp (name, "wchar_t")
68 || !strcmp (name, "char16_t")
69 || !strcmp (name, "char32_t"));
72 /* Apply a heuristic to decide whether an array of TYPE or a pointer
73 to TYPE should be printed as a textual string. Return non-zero if
74 it should, or zero if it should be treated as an array of integers
75 or pointer to integers. FORMAT is the current format letter, or 0
78 We guess that "char" is a character. Explicitly signed and
79 unsigned character types are also characters. Integer data from
80 vector types is not. The user can override this by using the /s
84 c_textual_element_type (struct type *type, char format)
86 struct type *true_type, *iter_type;
88 if (format != 0 && format != 's')
91 /* We also rely on this for its side effect of setting up all the
93 true_type = check_typedef (type);
95 /* TYPE_CODE_CHAR is always textual. */
96 if (TYPE_CODE (true_type) == TYPE_CODE_CHAR)
99 /* Any other character-like types must be integral. */
100 if (TYPE_CODE (true_type) != TYPE_CODE_INT)
103 /* We peel typedefs one by one, looking for a match. */
107 /* Check the name of the type. */
108 if (TYPE_NAME (iter_type) && textual_name (TYPE_NAME (iter_type)))
111 if (TYPE_CODE (iter_type) != TYPE_CODE_TYPEDEF)
114 /* Peel a single typedef. If the typedef doesn't have a target
115 type, we use check_typedef and hope the result is ok -- it
116 might be for C++, where wchar_t is a built-in type. */
117 if (TYPE_TARGET_TYPE (iter_type))
118 iter_type = TYPE_TARGET_TYPE (iter_type);
120 iter_type = check_typedef (iter_type);
125 /* Print this as a string if we can manage it. For now, no wide
126 character support. */
127 if (TYPE_CODE (true_type) == TYPE_CODE_INT
128 && TYPE_LENGTH (true_type) == 1)
133 /* If a one-byte TYPE_CODE_INT is missing the not-a-character
134 flag, then we treat it as text; otherwise, we assume it's
135 being used as data. */
136 if (TYPE_CODE (true_type) == TYPE_CODE_INT
137 && TYPE_LENGTH (true_type) == 1
138 && !TYPE_NOTTEXT (true_type))
145 /* See val_print for a description of the various parameters of this
146 function; they are identical. The semantics of the return value is
147 also identical to val_print. */
150 c_val_print (struct type *type, const gdb_byte *valaddr,
151 int embedded_offset, CORE_ADDR address,
152 struct ui_file *stream, int recurse,
153 const struct value *original_value,
154 const struct value_print_options *options)
156 struct gdbarch *gdbarch = get_type_arch (type);
157 enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
158 unsigned int i = 0; /* Number of characters printed. */
160 struct type *elttype, *unresolved_elttype;
161 struct type *unresolved_type = type;
166 CHECK_TYPEDEF (type);
167 switch (TYPE_CODE (type))
169 case TYPE_CODE_ARRAY:
170 unresolved_elttype = TYPE_TARGET_TYPE (type);
171 elttype = check_typedef (unresolved_elttype);
172 if (TYPE_LENGTH (type) > 0 && TYPE_LENGTH (unresolved_elttype) > 0)
174 LONGEST low_bound, high_bound;
176 if (!get_array_bounds (type, &low_bound, &high_bound))
177 error (_("Could not determine the array high bound"));
179 eltlen = TYPE_LENGTH (elttype);
180 len = high_bound - low_bound + 1;
181 if (options->prettyprint_arrays)
183 print_spaces_filtered (2 + 2 * recurse, stream);
186 /* Print arrays of textual chars with a string syntax, as
187 long as the entire array is valid. */
188 if (c_textual_element_type (unresolved_elttype,
190 && value_bytes_available (original_value, embedded_offset,
192 && value_bits_valid (original_value,
193 TARGET_CHAR_BIT * embedded_offset,
194 TARGET_CHAR_BIT * TYPE_LENGTH (type)))
196 /* If requested, look for the first null char and only
197 print elements up to it. */
198 if (options->stop_print_at_null)
200 unsigned int temp_len;
204 && temp_len < options->print_max
205 && extract_unsigned_integer (valaddr + embedded_offset
207 eltlen, byte_order) != 0);
213 LA_PRINT_STRING (stream, unresolved_elttype,
214 valaddr + embedded_offset, len,
220 fprintf_filtered (stream, "{");
221 /* If this is a virtual function table, print the 0th
222 entry specially, and the rest of the members
224 if (cp_is_vtbl_ptr_type (elttype))
227 fprintf_filtered (stream, _("%d vtable entries"),
234 val_print_array_elements (type, valaddr, embedded_offset,
236 recurse, original_value, options, i);
237 fprintf_filtered (stream, "}");
241 /* Array of unspecified length: treat like pointer to first
244 goto print_unpacked_pointer;
246 case TYPE_CODE_MEMBERPTR:
249 val_print_scalar_formatted (type, valaddr, embedded_offset,
250 original_value, options, 0, stream);
253 cp_print_class_member (valaddr + embedded_offset, type, stream, "&");
256 case TYPE_CODE_METHODPTR:
257 cplus_print_method_ptr (valaddr + embedded_offset, type, stream);
261 if (options->format && options->format != 's')
263 val_print_scalar_formatted (type, valaddr, embedded_offset,
264 original_value, options, 0, stream);
267 if (options->vtblprint && cp_is_vtbl_ptr_type (type))
269 /* Print the unmangled name if desired. */
270 /* Print vtable entry - we only get here if we ARE using
271 -fvtable_thunks. (Otherwise, look under
272 TYPE_CODE_STRUCT.) */
274 = extract_typed_address (valaddr + embedded_offset, type);
276 print_function_pointer_address (gdbarch, addr, stream,
277 options->addressprint);
280 unresolved_elttype = TYPE_TARGET_TYPE (type);
281 elttype = check_typedef (unresolved_elttype);
283 addr = unpack_pointer (type, valaddr + embedded_offset);
284 print_unpacked_pointer:
286 if (TYPE_CODE (elttype) == TYPE_CODE_FUNC)
288 /* Try to print what function it points to. */
289 print_function_pointer_address (gdbarch, addr, stream,
290 options->addressprint);
291 /* Return value is irrelevant except for string
296 if (options->addressprint)
297 fputs_filtered (paddress (gdbarch, addr), stream);
299 /* For a pointer to a textual type, also print the string
300 pointed to, unless pointer is null. */
302 if (c_textual_element_type (unresolved_elttype,
306 i = val_print_string (unresolved_elttype, NULL,
310 else if (cp_is_vtbl_member (type))
312 /* Print vtbl's nicely. */
313 CORE_ADDR vt_address = unpack_pointer (type,
317 struct minimal_symbol *msymbol =
318 lookup_minimal_symbol_by_pc (vt_address);
319 if ((msymbol != NULL)
320 && (vt_address == SYMBOL_VALUE_ADDRESS (msymbol)))
322 fputs_filtered (" <", stream);
323 fputs_filtered (SYMBOL_PRINT_NAME (msymbol), stream);
324 fputs_filtered (">", stream);
326 if (vt_address && options->vtblprint)
328 struct value *vt_val;
329 struct symbol *wsym = (struct symbol *) NULL;
331 struct block *block = (struct block *) NULL;
335 wsym = lookup_symbol (SYMBOL_LINKAGE_NAME (msymbol),
341 wtype = SYMBOL_TYPE (wsym);
345 wtype = unresolved_elttype;
347 vt_val = value_at (wtype, vt_address);
348 common_val_print (vt_val, stream, recurse + 1,
349 options, current_language);
352 fprintf_filtered (stream, "\n");
353 print_spaces_filtered (2 + 2 * recurse, stream);
358 /* Return number of characters printed, including the
359 terminating '\0' if we reached the end. val_print_string
360 takes care including the terminating '\0' if
367 elttype = check_typedef (TYPE_TARGET_TYPE (type));
368 if (options->addressprint)
371 = extract_typed_address (valaddr + embedded_offset, type);
373 fprintf_filtered (stream, "@");
374 fputs_filtered (paddress (gdbarch, addr), stream);
375 if (options->deref_ref)
376 fputs_filtered (": ", stream);
378 /* De-reference the reference. */
379 if (options->deref_ref)
381 if (TYPE_CODE (elttype) != TYPE_CODE_UNDEF)
383 struct value *deref_val =
385 (TYPE_TARGET_TYPE (type),
386 unpack_pointer (type, valaddr + embedded_offset));
388 common_val_print (deref_val, stream, recurse, options,
392 fputs_filtered ("???", stream);
396 case TYPE_CODE_UNION:
397 if (recurse && !options->unionprint)
399 fprintf_filtered (stream, "{...}");
403 case TYPE_CODE_STRUCT:
404 /*FIXME: Abstract this away. */
405 if (options->vtblprint && cp_is_vtbl_ptr_type (type))
407 /* Print the unmangled name if desired. */
408 /* Print vtable entry - we only get here if NOT using
409 -fvtable_thunks. (Otherwise, look under
411 int offset = (embedded_offset
412 + TYPE_FIELD_BITPOS (type,
413 VTBL_FNADDR_OFFSET) / 8);
414 struct type *field_type = TYPE_FIELD_TYPE (type,
417 = extract_typed_address (valaddr + offset, field_type);
419 print_function_pointer_address (gdbarch, addr, stream,
420 options->addressprint);
423 cp_print_value_fields_rtti (type, valaddr,
424 embedded_offset, address,
426 original_value, options,
433 val_print_scalar_formatted (type, valaddr, embedded_offset,
434 original_value, options, 0, stream);
437 len = TYPE_NFIELDS (type);
438 val = unpack_long (type, valaddr + embedded_offset);
439 for (i = 0; i < len; i++)
442 if (val == TYPE_FIELD_BITPOS (type, i))
449 fputs_filtered (TYPE_FIELD_NAME (type, i), stream);
453 print_longest (stream, 'd', 0, val);
457 case TYPE_CODE_FLAGS:
459 val_print_scalar_formatted (type, valaddr, embedded_offset,
460 original_value, options, 0, stream);
462 val_print_type_code_flags (type, valaddr + embedded_offset,
467 case TYPE_CODE_METHOD:
470 val_print_scalar_formatted (type, valaddr, embedded_offset,
471 original_value, options, 0, stream);
474 /* FIXME, we should consider, at least for ANSI C language,
475 eliminating the distinction made between FUNCs and POINTERs
477 fprintf_filtered (stream, "{");
478 type_print (type, "", stream, -1);
479 fprintf_filtered (stream, "} ");
480 /* Try to print what function it points to, and its address. */
481 print_address_demangle (gdbarch, address, stream, demangle);
485 if (options->format || options->output_format)
487 struct value_print_options opts = *options;
488 opts.format = (options->format ? options->format
489 : options->output_format);
490 val_print_scalar_formatted (type, valaddr, embedded_offset,
491 original_value, &opts, 0, stream);
495 val = unpack_long (type, valaddr + embedded_offset);
497 fputs_filtered ("false", stream);
499 fputs_filtered ("true", stream);
501 print_longest (stream, 'd', 0, val);
505 case TYPE_CODE_RANGE:
506 /* FIXME: create_range_type does not set the unsigned bit in a
507 range type (I think it probably should copy it from the
508 target type), so we won't print values which are too large to
509 fit in a signed integer correctly. */
510 /* FIXME: Doesn't handle ranges of enums correctly. (Can't just
511 print with the target type, though, because the size of our
512 type and the target type might differ). */
516 if (options->format || options->output_format)
518 struct value_print_options opts = *options;
520 opts.format = (options->format ? options->format
521 : options->output_format);
522 val_print_scalar_formatted (type, valaddr, embedded_offset,
523 original_value, &opts, 0, stream);
527 val_print_type_code_int (type, valaddr + embedded_offset,
529 /* C and C++ has no single byte int type, char is used
530 instead. Since we don't know whether the value is really
531 intended to be used as an integer or a character, print
532 the character equivalent as well. */
533 if (c_textual_element_type (unresolved_type, options->format))
535 fputs_filtered (" ", stream);
536 LA_PRINT_CHAR (unpack_long (type, valaddr + embedded_offset),
537 unresolved_type, stream);
543 if (options->format || options->output_format)
545 struct value_print_options opts = *options;
546 opts.format = (options->format ? options->format
547 : options->output_format);
548 val_print_scalar_formatted (type, valaddr, embedded_offset,
549 original_value, &opts, 0, stream);
553 val = unpack_long (type, valaddr + embedded_offset);
554 if (TYPE_UNSIGNED (type))
555 fprintf_filtered (stream, "%u", (unsigned int) val);
557 fprintf_filtered (stream, "%d", (int) val);
558 fputs_filtered (" ", stream);
559 LA_PRINT_CHAR (val, unresolved_type, stream);
566 val_print_scalar_formatted (type, valaddr, embedded_offset,
567 original_value, options, 0, stream);
571 print_floating (valaddr + embedded_offset, type, stream);
575 case TYPE_CODE_DECFLOAT:
577 val_print_scalar_formatted (type, valaddr, embedded_offset,
578 original_value, options, 0, stream);
580 print_decimal_floating (valaddr + embedded_offset,
585 fprintf_filtered (stream, "void");
588 case TYPE_CODE_ERROR:
589 fprintf_filtered (stream, "%s", TYPE_ERROR_NAME (type));
592 case TYPE_CODE_UNDEF:
593 /* This happens (without TYPE_FLAG_STUB set) on systems which
594 don't use dbx xrefs (NO_DBX_XREFS in gcc) if a file has a
595 "struct foo *bar" and no complete type for struct foo in that
597 fprintf_filtered (stream, _("<incomplete type>"));
600 case TYPE_CODE_COMPLEX:
602 val_print_scalar_formatted (TYPE_TARGET_TYPE (type),
603 valaddr, embedded_offset,
604 original_value, options, 0, stream);
606 print_floating (valaddr + embedded_offset,
607 TYPE_TARGET_TYPE (type),
609 fprintf_filtered (stream, " + ");
611 val_print_scalar_formatted (TYPE_TARGET_TYPE (type),
614 + TYPE_LENGTH (TYPE_TARGET_TYPE (type)),
618 print_floating (valaddr + embedded_offset
619 + TYPE_LENGTH (TYPE_TARGET_TYPE (type)),
620 TYPE_TARGET_TYPE (type),
622 fprintf_filtered (stream, " * I");
626 error (_("Invalid C/C++ type code %d in symbol table."),
634 c_value_print (struct value *val, struct ui_file *stream,
635 const struct value_print_options *options)
637 struct type *type, *real_type, *val_type;
638 int full, top, using_enc;
639 struct value_print_options opts = *options;
643 /* If it is a pointer, indicate what it points to.
645 Print type also if it is a reference.
647 C++: if it is a member pointer, we will take care
648 of that when we print it. */
650 /* Preserve the original type before stripping typedefs. We prefer
651 to pass down the original type when possible, but for local
652 checks it is better to look past the typedefs. */
653 val_type = value_type (val);
654 type = check_typedef (val_type);
656 if (TYPE_CODE (type) == TYPE_CODE_PTR
657 || TYPE_CODE (type) == TYPE_CODE_REF)
659 /* Hack: remove (char *) for char strings. Their
660 type is indicated by the quoted string anyway.
661 (Don't use c_textual_element_type here; quoted strings
662 are always exactly (char *), (wchar_t *), or the like. */
663 if (TYPE_CODE (val_type) == TYPE_CODE_PTR
664 && TYPE_NAME (val_type) == NULL
665 && TYPE_NAME (TYPE_TARGET_TYPE (val_type)) != NULL
666 && (strcmp (TYPE_NAME (TYPE_TARGET_TYPE (val_type)),
668 || textual_name (TYPE_NAME (TYPE_TARGET_TYPE (val_type)))))
672 else if (options->objectprint
673 && (TYPE_CODE (TYPE_TARGET_TYPE (type)) == TYPE_CODE_CLASS))
676 if (TYPE_CODE(type) == TYPE_CODE_REF)
678 /* Copy value, change to pointer, so we don't get an
679 error about a non-pointer type in
680 value_rtti_target_type. */
681 struct value *temparg;
682 temparg=value_copy(val);
683 deprecated_set_value_type
684 (temparg, lookup_pointer_type (TYPE_TARGET_TYPE (type)));
687 /* Pointer to class, check real type of object. */
688 fprintf_filtered (stream, "(");
689 real_type = value_rtti_target_type (val, &full,
693 /* RTTI entry found. */
694 if (TYPE_CODE (type) == TYPE_CODE_PTR)
696 /* Create a pointer type pointing to the real
698 type = lookup_pointer_type (real_type);
702 /* Create a reference type referencing the real
704 type = lookup_reference_type (real_type);
706 /* JYG: Need to adjust pointer value. */
707 val = value_from_pointer (type, value_as_address (val) - top);
709 /* Note: When we look up RTTI entries, we don't get any
710 information on const or volatile attributes. */
712 type_print (type, "", stream, -1);
713 fprintf_filtered (stream, ") ");
719 fprintf_filtered (stream, "(");
720 type_print (value_type (val), "", stream, -1);
721 fprintf_filtered (stream, ") ");
725 if (!value_initialized (val))
726 fprintf_filtered (stream, " [uninitialized] ");
728 if (options->objectprint && (TYPE_CODE (type) == TYPE_CODE_CLASS))
730 /* Attempt to determine real type of object. */
731 real_type = value_rtti_type (val, &full, &top, &using_enc);
734 /* We have RTTI information, so use it. */
735 val = value_full_object (val, real_type,
736 full, top, using_enc);
737 fprintf_filtered (stream, "(%s%s) ",
738 TYPE_NAME (real_type),
739 full ? "" : _(" [incomplete object]"));
740 /* Print out object: enclosing type is same as real_type if
742 return val_print (value_enclosing_type (val),
743 value_contents_for_printing (val), 0,
744 value_address (val), stream, 0,
745 val, &opts, current_language);
746 /* Note: When we look up RTTI entries, we don't get any
747 information on const or volatile attributes. */
749 else if (type != check_typedef (value_enclosing_type (val)))
751 /* No RTTI information, so let's do our best. */
752 fprintf_filtered (stream, "(%s ?) ",
753 TYPE_NAME (value_enclosing_type (val)));
754 return val_print (value_enclosing_type (val),
755 value_contents_for_printing (val), 0,
756 value_address (val), stream, 0,
757 val, &opts, current_language);
759 /* Otherwise, we end up at the return outside this "if". */
762 return val_print (val_type, value_contents_for_printing (val),
763 value_embedded_offset (val),
766 val, &opts, current_language);