1 /* Support for printing C values for GDB, the GNU debugger.
3 Copyright (C) 1986-2014 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/>. */
24 #include "expression.h"
34 /* A helper for c_textual_element_type. This checks the name of the
35 typedef. This is bogus but it isn't apparent that the compiler
36 provides us the help we may need. */
39 textual_name (const char *name)
41 return (!strcmp (name, "wchar_t")
42 || !strcmp (name, "char16_t")
43 || !strcmp (name, "char32_t"));
46 /* Apply a heuristic to decide whether an array of TYPE or a pointer
47 to TYPE should be printed as a textual string. Return non-zero if
48 it should, or zero if it should be treated as an array of integers
49 or pointer to integers. FORMAT is the current format letter, or 0
52 We guess that "char" is a character. Explicitly signed and
53 unsigned character types are also characters. Integer data from
54 vector types is not. The user can override this by using the /s
58 c_textual_element_type (struct type *type, char format)
60 struct type *true_type, *iter_type;
62 if (format != 0 && format != 's')
65 /* We also rely on this for its side effect of setting up all the
67 true_type = check_typedef (type);
69 /* TYPE_CODE_CHAR is always textual. */
70 if (TYPE_CODE (true_type) == TYPE_CODE_CHAR)
73 /* Any other character-like types must be integral. */
74 if (TYPE_CODE (true_type) != TYPE_CODE_INT)
77 /* We peel typedefs one by one, looking for a match. */
81 /* Check the name of the type. */
82 if (TYPE_NAME (iter_type) && textual_name (TYPE_NAME (iter_type)))
85 if (TYPE_CODE (iter_type) != TYPE_CODE_TYPEDEF)
88 /* Peel a single typedef. If the typedef doesn't have a target
89 type, we use check_typedef and hope the result is ok -- it
90 might be for C++, where wchar_t is a built-in type. */
91 if (TYPE_TARGET_TYPE (iter_type))
92 iter_type = TYPE_TARGET_TYPE (iter_type);
94 iter_type = check_typedef (iter_type);
99 /* Print this as a string if we can manage it. For now, no wide
100 character support. */
101 if (TYPE_CODE (true_type) == TYPE_CODE_INT
102 && TYPE_LENGTH (true_type) == 1)
107 /* If a one-byte TYPE_CODE_INT is missing the not-a-character
108 flag, then we treat it as text; otherwise, we assume it's
109 being used as data. */
110 if (TYPE_CODE (true_type) == TYPE_CODE_INT
111 && TYPE_LENGTH (true_type) == 1
112 && !TYPE_NOTTEXT (true_type))
119 /* Decorations for C. */
121 static const struct generic_val_print_decorations c_decorations =
131 /* See val_print for a description of the various parameters of this
132 function; they are identical. */
135 c_val_print (struct type *type, const gdb_byte *valaddr,
136 int embedded_offset, CORE_ADDR address,
137 struct ui_file *stream, int recurse,
138 const struct value *original_value,
139 const struct value_print_options *options)
141 struct gdbarch *gdbarch = get_type_arch (type);
142 enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
143 unsigned int i = 0; /* Number of characters printed. */
145 struct type *elttype, *unresolved_elttype;
146 struct type *unresolved_type = type;
150 CHECK_TYPEDEF (type);
151 switch (TYPE_CODE (type))
153 case TYPE_CODE_ARRAY:
154 unresolved_elttype = TYPE_TARGET_TYPE (type);
155 elttype = check_typedef (unresolved_elttype);
156 if (TYPE_LENGTH (type) > 0 && TYPE_LENGTH (unresolved_elttype) > 0)
158 LONGEST low_bound, high_bound;
160 if (!get_array_bounds (type, &low_bound, &high_bound))
161 error (_("Could not determine the array high bound"));
163 eltlen = TYPE_LENGTH (elttype);
164 len = high_bound - low_bound + 1;
165 if (options->prettyformat_arrays)
167 print_spaces_filtered (2 + 2 * recurse, stream);
170 /* Print arrays of textual chars with a string syntax, as
171 long as the entire array is valid. */
172 if (c_textual_element_type (unresolved_elttype,
174 && value_bytes_available (original_value, embedded_offset,
176 && value_bits_valid (original_value,
177 TARGET_CHAR_BIT * embedded_offset,
178 TARGET_CHAR_BIT * TYPE_LENGTH (type)))
180 int force_ellipses = 0;
182 /* If requested, look for the first null char and only
183 print elements up to it. */
184 if (options->stop_print_at_null)
186 unsigned int temp_len;
190 && temp_len < options->print_max
191 && extract_unsigned_integer (valaddr + embedded_offset
193 eltlen, byte_order) != 0);
197 /* Force LA_PRINT_STRING to print ellipses if
198 we've printed the maximum characters and
199 the next character is not \000. */
200 if (temp_len == options->print_max && temp_len < len)
203 = extract_unsigned_integer (valaddr + embedded_offset
213 LA_PRINT_STRING (stream, unresolved_elttype,
214 valaddr + embedded_offset, len,
215 NULL, force_ellipses, options);
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
243 addr = address + embedded_offset;
244 goto print_unpacked_pointer;
246 case TYPE_CODE_METHODPTR:
247 cplus_print_method_ptr (valaddr + embedded_offset, type, stream);
251 if (options->format && options->format != 's')
253 val_print_scalar_formatted (type, valaddr, embedded_offset,
254 original_value, options, 0, stream);
257 if (options->vtblprint && cp_is_vtbl_ptr_type (type))
259 /* Print the unmangled name if desired. */
260 /* Print vtable entry - we only get here if we ARE using
261 -fvtable_thunks. (Otherwise, look under
262 TYPE_CODE_STRUCT.) */
264 = extract_typed_address (valaddr + embedded_offset, type);
266 print_function_pointer_address (options, gdbarch, addr, stream);
269 unresolved_elttype = TYPE_TARGET_TYPE (type);
270 elttype = check_typedef (unresolved_elttype);
274 addr = unpack_pointer (type, valaddr + embedded_offset);
275 print_unpacked_pointer:
279 if (TYPE_CODE (elttype) == TYPE_CODE_FUNC)
281 /* Try to print what function it points to. */
282 print_function_pointer_address (options, gdbarch, addr, stream);
286 if (options->symbol_print)
287 want_space = print_address_demangle (options, gdbarch, addr,
289 else if (options->addressprint)
291 fputs_filtered (paddress (gdbarch, addr), stream);
295 /* For a pointer to a textual type, also print the string
296 pointed to, unless pointer is null. */
298 if (c_textual_element_type (unresolved_elttype,
303 fputs_filtered (" ", stream);
304 i = val_print_string (unresolved_elttype, NULL,
308 else if (cp_is_vtbl_member (type))
310 /* Print vtbl's nicely. */
311 CORE_ADDR vt_address = unpack_pointer (type,
314 struct bound_minimal_symbol msymbol =
315 lookup_minimal_symbol_by_pc (vt_address);
317 /* If 'symbol_print' is set, we did the work above. */
318 if (!options->symbol_print
319 && (msymbol.minsym != NULL)
320 && (vt_address == BMSYMBOL_VALUE_ADDRESS (msymbol)))
323 fputs_filtered (" ", stream);
324 fputs_filtered (" <", stream);
325 fputs_filtered (MSYMBOL_PRINT_NAME (msymbol.minsym), stream);
326 fputs_filtered (">", stream);
330 if (vt_address && options->vtblprint)
332 struct value *vt_val;
333 struct symbol *wsym = (struct symbol *) NULL;
335 struct block *block = (struct block *) NULL;
336 struct field_of_this_result is_this_fld;
339 fputs_filtered (" ", stream);
341 if (msymbol.minsym != NULL)
342 wsym = lookup_symbol (MSYMBOL_LINKAGE_NAME (msymbol.minsym),
348 wtype = SYMBOL_TYPE (wsym);
352 wtype = unresolved_elttype;
354 vt_val = value_at (wtype, vt_address);
355 common_val_print (vt_val, stream, recurse + 1,
356 options, current_language);
357 if (options->prettyformat)
359 fprintf_filtered (stream, "\n");
360 print_spaces_filtered (2 + 2 * recurse, stream);
368 case TYPE_CODE_UNION:
369 if (recurse && !options->unionprint)
371 fprintf_filtered (stream, "{...}");
375 case TYPE_CODE_STRUCT:
376 /*FIXME: Abstract this away. */
377 if (options->vtblprint && cp_is_vtbl_ptr_type (type))
379 /* Print the unmangled name if desired. */
380 /* Print vtable entry - we only get here if NOT using
381 -fvtable_thunks. (Otherwise, look under
383 int offset = (embedded_offset
384 + TYPE_FIELD_BITPOS (type,
385 VTBL_FNADDR_OFFSET) / 8);
386 struct type *field_type = TYPE_FIELD_TYPE (type,
389 = extract_typed_address (valaddr + offset, field_type);
391 print_function_pointer_address (options, gdbarch, addr, stream);
394 cp_print_value_fields_rtti (type, valaddr,
395 embedded_offset, address,
397 original_value, options,
402 if (options->format || options->output_format)
404 struct value_print_options opts = *options;
406 opts.format = (options->format ? options->format
407 : options->output_format);
408 val_print_scalar_formatted (type, valaddr, embedded_offset,
409 original_value, &opts, 0, stream);
413 val_print_type_code_int (type, valaddr + embedded_offset,
415 /* C and C++ has no single byte int type, char is used
416 instead. Since we don't know whether the value is really
417 intended to be used as an integer or a character, print
418 the character equivalent as well. */
419 if (c_textual_element_type (unresolved_type, options->format))
421 fputs_filtered (" ", stream);
422 LA_PRINT_CHAR (unpack_long (type, valaddr + embedded_offset),
423 unresolved_type, stream);
428 case TYPE_CODE_MEMBERPTR:
429 if (!options->format)
431 cp_print_class_member (valaddr + embedded_offset, type, stream, "&");
438 case TYPE_CODE_FLAGS:
440 case TYPE_CODE_METHOD:
442 case TYPE_CODE_RANGE:
444 case TYPE_CODE_DECFLOAT:
446 case TYPE_CODE_ERROR:
447 case TYPE_CODE_UNDEF:
448 case TYPE_CODE_COMPLEX:
451 generic_val_print (type, valaddr, embedded_offset, address,
452 stream, recurse, original_value, options,
460 c_value_print (struct value *val, struct ui_file *stream,
461 const struct value_print_options *options)
463 struct type *type, *real_type, *val_type;
464 int full, top, using_enc;
465 struct value_print_options opts = *options;
469 /* If it is a pointer, indicate what it points to.
471 Print type also if it is a reference.
473 C++: if it is a member pointer, we will take care
474 of that when we print it. */
476 /* Preserve the original type before stripping typedefs. We prefer
477 to pass down the original type when possible, but for local
478 checks it is better to look past the typedefs. */
479 val_type = value_type (val);
480 type = check_typedef (val_type);
482 if (TYPE_CODE (type) == TYPE_CODE_PTR
483 || TYPE_CODE (type) == TYPE_CODE_REF)
485 /* Hack: remove (char *) for char strings. Their
486 type is indicated by the quoted string anyway.
487 (Don't use c_textual_element_type here; quoted strings
488 are always exactly (char *), (wchar_t *), or the like. */
489 if (TYPE_CODE (val_type) == TYPE_CODE_PTR
490 && TYPE_NAME (val_type) == NULL
491 && TYPE_NAME (TYPE_TARGET_TYPE (val_type)) != NULL
492 && (strcmp (TYPE_NAME (TYPE_TARGET_TYPE (val_type)),
494 || textual_name (TYPE_NAME (TYPE_TARGET_TYPE (val_type)))))
498 else if (options->objectprint
499 && (TYPE_CODE (TYPE_TARGET_TYPE (type)) == TYPE_CODE_CLASS))
501 int is_ref = TYPE_CODE (type) == TYPE_CODE_REF;
504 val = value_addr (val);
506 /* Pointer to class, check real type of object. */
507 fprintf_filtered (stream, "(");
509 if (value_entirely_available (val))
511 real_type = value_rtti_indirect_type (val, &full, &top,
515 /* RTTI entry found. */
518 /* Need to adjust pointer value. */
519 val = value_from_pointer (real_type,
520 value_as_address (val) - top);
524 val = value_ref (value_ind (val));
525 type = value_type (val);
528 /* Note: When we look up RTTI entries, we don't get
529 any information on const or volatile
533 type_print (type, "", stream, -1);
534 fprintf_filtered (stream, ") ");
540 fprintf_filtered (stream, "(");
541 type_print (value_type (val), "", stream, -1);
542 fprintf_filtered (stream, ") ");
546 if (!value_initialized (val))
547 fprintf_filtered (stream, " [uninitialized] ");
549 if (options->objectprint && (TYPE_CODE (type) == TYPE_CODE_CLASS))
551 /* Attempt to determine real type of object. */
552 real_type = value_rtti_type (val, &full, &top, &using_enc);
555 /* We have RTTI information, so use it. */
556 val = value_full_object (val, real_type,
557 full, top, using_enc);
558 fprintf_filtered (stream, "(%s%s) ",
559 TYPE_NAME (real_type),
560 full ? "" : _(" [incomplete object]"));
561 /* Print out object: enclosing type is same as real_type if
563 val_print (value_enclosing_type (val),
564 value_contents_for_printing (val), 0,
565 value_address (val), stream, 0,
566 val, &opts, current_language);
568 /* Note: When we look up RTTI entries, we don't get any
569 information on const or volatile attributes. */
571 else if (type != check_typedef (value_enclosing_type (val)))
573 /* No RTTI information, so let's do our best. */
574 fprintf_filtered (stream, "(%s ?) ",
575 TYPE_NAME (value_enclosing_type (val)));
576 val_print (value_enclosing_type (val),
577 value_contents_for_printing (val), 0,
578 value_address (val), stream, 0,
579 val, &opts, current_language);
582 /* Otherwise, we end up at the return outside this "if". */
585 val_print (val_type, value_contents_for_printing (val),
586 value_embedded_offset (val),
589 val, &opts, current_language);