590 lines
17 KiB
C
590 lines
17 KiB
C
/* Support for printing C values for GDB, the GNU debugger.
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Copyright (C) 1986-2013 Free Software Foundation, Inc.
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This file is part of GDB.
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 3 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program. If not, see <http://www.gnu.org/licenses/>. */
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#include "defs.h"
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#include "gdb_string.h"
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#include "symtab.h"
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#include "gdbtypes.h"
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#include "expression.h"
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#include "value.h"
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#include "valprint.h"
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#include "language.h"
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#include "c-lang.h"
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#include "cp-abi.h"
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#include "target.h"
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/* A helper for c_textual_element_type. This checks the name of the
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typedef. This is bogus but it isn't apparent that the compiler
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provides us the help we may need. */
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static int
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textual_name (const char *name)
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{
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return (!strcmp (name, "wchar_t")
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|| !strcmp (name, "char16_t")
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|| !strcmp (name, "char32_t"));
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}
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/* Apply a heuristic to decide whether an array of TYPE or a pointer
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to TYPE should be printed as a textual string. Return non-zero if
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it should, or zero if it should be treated as an array of integers
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or pointer to integers. FORMAT is the current format letter, or 0
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if none.
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We guess that "char" is a character. Explicitly signed and
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unsigned character types are also characters. Integer data from
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vector types is not. The user can override this by using the /s
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format letter. */
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int
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c_textual_element_type (struct type *type, char format)
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{
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struct type *true_type, *iter_type;
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if (format != 0 && format != 's')
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return 0;
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/* We also rely on this for its side effect of setting up all the
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typedef pointers. */
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true_type = check_typedef (type);
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/* TYPE_CODE_CHAR is always textual. */
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if (TYPE_CODE (true_type) == TYPE_CODE_CHAR)
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return 1;
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/* Any other character-like types must be integral. */
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if (TYPE_CODE (true_type) != TYPE_CODE_INT)
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return 0;
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/* We peel typedefs one by one, looking for a match. */
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iter_type = type;
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while (iter_type)
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{
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/* Check the name of the type. */
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if (TYPE_NAME (iter_type) && textual_name (TYPE_NAME (iter_type)))
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return 1;
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if (TYPE_CODE (iter_type) != TYPE_CODE_TYPEDEF)
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break;
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/* Peel a single typedef. If the typedef doesn't have a target
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type, we use check_typedef and hope the result is ok -- it
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might be for C++, where wchar_t is a built-in type. */
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if (TYPE_TARGET_TYPE (iter_type))
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iter_type = TYPE_TARGET_TYPE (iter_type);
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else
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iter_type = check_typedef (iter_type);
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}
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if (format == 's')
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{
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/* Print this as a string if we can manage it. For now, no wide
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character support. */
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if (TYPE_CODE (true_type) == TYPE_CODE_INT
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&& TYPE_LENGTH (true_type) == 1)
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return 1;
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}
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else
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{
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/* If a one-byte TYPE_CODE_INT is missing the not-a-character
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flag, then we treat it as text; otherwise, we assume it's
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being used as data. */
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if (TYPE_CODE (true_type) == TYPE_CODE_INT
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&& TYPE_LENGTH (true_type) == 1
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&& !TYPE_NOTTEXT (true_type))
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return 1;
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}
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return 0;
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}
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/* Decorations for C. */
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static const struct generic_val_print_decorations c_decorations =
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{
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"",
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" + ",
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" * I",
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"true",
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"false",
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"void"
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};
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/* See val_print for a description of the various parameters of this
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function; they are identical. */
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void
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c_val_print (struct type *type, const gdb_byte *valaddr,
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int embedded_offset, CORE_ADDR address,
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struct ui_file *stream, int recurse,
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const struct value *original_value,
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const struct value_print_options *options)
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{
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struct gdbarch *gdbarch = get_type_arch (type);
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enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
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unsigned int i = 0; /* Number of characters printed. */
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unsigned len;
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struct type *elttype, *unresolved_elttype;
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struct type *unresolved_type = type;
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unsigned eltlen;
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CORE_ADDR addr;
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CHECK_TYPEDEF (type);
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switch (TYPE_CODE (type))
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{
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case TYPE_CODE_ARRAY:
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unresolved_elttype = TYPE_TARGET_TYPE (type);
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elttype = check_typedef (unresolved_elttype);
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if (TYPE_LENGTH (type) > 0 && TYPE_LENGTH (unresolved_elttype) > 0)
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{
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LONGEST low_bound, high_bound;
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if (!get_array_bounds (type, &low_bound, &high_bound))
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error (_("Could not determine the array high bound"));
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eltlen = TYPE_LENGTH (elttype);
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len = high_bound - low_bound + 1;
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if (options->prettyformat_arrays)
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{
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print_spaces_filtered (2 + 2 * recurse, stream);
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}
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/* Print arrays of textual chars with a string syntax, as
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long as the entire array is valid. */
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if (c_textual_element_type (unresolved_elttype,
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options->format)
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&& value_bytes_available (original_value, embedded_offset,
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TYPE_LENGTH (type))
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&& value_bits_valid (original_value,
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TARGET_CHAR_BIT * embedded_offset,
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TARGET_CHAR_BIT * TYPE_LENGTH (type)))
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{
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int force_ellipses = 0;
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/* If requested, look for the first null char and only
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print elements up to it. */
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if (options->stop_print_at_null)
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{
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unsigned int temp_len;
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for (temp_len = 0;
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(temp_len < len
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&& temp_len < options->print_max
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&& extract_unsigned_integer (valaddr + embedded_offset
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+ temp_len * eltlen,
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eltlen, byte_order) != 0);
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++temp_len)
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;
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/* Force LA_PRINT_STRING to print ellipses if
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we've printed the maximum characters and
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the next character is not \000. */
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if (temp_len == options->print_max && temp_len < len)
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{
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ULONGEST val
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= extract_unsigned_integer (valaddr + embedded_offset
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+ temp_len * eltlen,
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eltlen, byte_order);
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if (val != 0)
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force_ellipses = 1;
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}
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len = temp_len;
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}
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LA_PRINT_STRING (stream, unresolved_elttype,
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valaddr + embedded_offset, len,
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NULL, force_ellipses, options);
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i = len;
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}
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else
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{
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fprintf_filtered (stream, "{");
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/* If this is a virtual function table, print the 0th
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entry specially, and the rest of the members
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normally. */
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if (cp_is_vtbl_ptr_type (elttype))
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{
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i = 1;
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fprintf_filtered (stream, _("%d vtable entries"),
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len - 1);
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}
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else
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{
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i = 0;
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}
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val_print_array_elements (type, valaddr, embedded_offset,
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address, stream,
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recurse, original_value, options, i);
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fprintf_filtered (stream, "}");
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}
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break;
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}
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/* Array of unspecified length: treat like pointer to first
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elt. */
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addr = address + embedded_offset;
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goto print_unpacked_pointer;
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case TYPE_CODE_METHODPTR:
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cplus_print_method_ptr (valaddr + embedded_offset, type, stream);
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break;
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case TYPE_CODE_PTR:
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if (options->format && options->format != 's')
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{
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val_print_scalar_formatted (type, valaddr, embedded_offset,
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original_value, options, 0, stream);
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break;
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}
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if (options->vtblprint && cp_is_vtbl_ptr_type (type))
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{
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/* Print the unmangled name if desired. */
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/* Print vtable entry - we only get here if we ARE using
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-fvtable_thunks. (Otherwise, look under
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TYPE_CODE_STRUCT.) */
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CORE_ADDR addr
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= extract_typed_address (valaddr + embedded_offset, type);
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print_function_pointer_address (options, gdbarch, addr, stream);
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break;
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}
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unresolved_elttype = TYPE_TARGET_TYPE (type);
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elttype = check_typedef (unresolved_elttype);
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{
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int want_space;
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addr = unpack_pointer (type, valaddr + embedded_offset);
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print_unpacked_pointer:
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want_space = 0;
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if (TYPE_CODE (elttype) == TYPE_CODE_FUNC)
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{
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/* Try to print what function it points to. */
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print_function_pointer_address (options, gdbarch, addr, stream);
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return;
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}
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if (options->symbol_print)
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want_space = print_address_demangle (options, gdbarch, addr,
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stream, demangle);
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else if (options->addressprint)
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{
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fputs_filtered (paddress (gdbarch, addr), stream);
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want_space = 1;
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}
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/* For a pointer to a textual type, also print the string
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pointed to, unless pointer is null. */
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if (c_textual_element_type (unresolved_elttype,
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options->format)
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&& addr != 0)
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{
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if (want_space)
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fputs_filtered (" ", stream);
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i = val_print_string (unresolved_elttype, NULL,
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addr, -1,
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stream, options);
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}
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else if (cp_is_vtbl_member (type))
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{
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/* Print vtbl's nicely. */
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CORE_ADDR vt_address = unpack_pointer (type,
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valaddr
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+ embedded_offset);
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struct bound_minimal_symbol msymbol =
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lookup_minimal_symbol_by_pc (vt_address);
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/* If 'symbol_print' is set, we did the work above. */
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if (!options->symbol_print
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&& (msymbol.minsym != NULL)
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&& (vt_address == SYMBOL_VALUE_ADDRESS (msymbol.minsym)))
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{
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if (want_space)
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fputs_filtered (" ", stream);
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fputs_filtered (" <", stream);
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fputs_filtered (SYMBOL_PRINT_NAME (msymbol.minsym), stream);
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fputs_filtered (">", stream);
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want_space = 1;
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}
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if (vt_address && options->vtblprint)
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{
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struct value *vt_val;
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struct symbol *wsym = (struct symbol *) NULL;
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struct type *wtype;
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struct block *block = (struct block *) NULL;
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struct field_of_this_result is_this_fld;
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if (want_space)
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fputs_filtered (" ", stream);
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if (msymbol.minsym != NULL)
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wsym = lookup_symbol (SYMBOL_LINKAGE_NAME (msymbol.minsym),
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block, VAR_DOMAIN,
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&is_this_fld);
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if (wsym)
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{
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wtype = SYMBOL_TYPE (wsym);
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}
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else
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{
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wtype = unresolved_elttype;
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}
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vt_val = value_at (wtype, vt_address);
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common_val_print (vt_val, stream, recurse + 1,
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options, current_language);
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if (options->prettyformat)
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{
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fprintf_filtered (stream, "\n");
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print_spaces_filtered (2 + 2 * recurse, stream);
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}
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}
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}
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return;
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}
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break;
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case TYPE_CODE_UNION:
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if (recurse && !options->unionprint)
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{
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fprintf_filtered (stream, "{...}");
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break;
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}
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/* Fall through. */
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case TYPE_CODE_STRUCT:
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/*FIXME: Abstract this away. */
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if (options->vtblprint && cp_is_vtbl_ptr_type (type))
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{
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/* Print the unmangled name if desired. */
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/* Print vtable entry - we only get here if NOT using
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-fvtable_thunks. (Otherwise, look under
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TYPE_CODE_PTR.) */
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int offset = (embedded_offset
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+ TYPE_FIELD_BITPOS (type,
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VTBL_FNADDR_OFFSET) / 8);
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struct type *field_type = TYPE_FIELD_TYPE (type,
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VTBL_FNADDR_OFFSET);
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CORE_ADDR addr
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= extract_typed_address (valaddr + offset, field_type);
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print_function_pointer_address (options, gdbarch, addr, stream);
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}
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else
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cp_print_value_fields_rtti (type, valaddr,
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embedded_offset, address,
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stream, recurse,
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original_value, options,
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NULL, 0);
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break;
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case TYPE_CODE_INT:
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if (options->format || options->output_format)
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{
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struct value_print_options opts = *options;
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opts.format = (options->format ? options->format
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: options->output_format);
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val_print_scalar_formatted (type, valaddr, embedded_offset,
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original_value, &opts, 0, stream);
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}
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else
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{
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val_print_type_code_int (type, valaddr + embedded_offset,
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stream);
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/* C and C++ has no single byte int type, char is used
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instead. Since we don't know whether the value is really
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intended to be used as an integer or a character, print
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the character equivalent as well. */
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if (c_textual_element_type (unresolved_type, options->format))
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{
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fputs_filtered (" ", stream);
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LA_PRINT_CHAR (unpack_long (type, valaddr + embedded_offset),
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unresolved_type, stream);
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}
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}
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break;
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case TYPE_CODE_MEMBERPTR:
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if (!options->format)
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{
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cp_print_class_member (valaddr + embedded_offset, type, stream, "&");
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break;
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}
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/* FALLTHROUGH */
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case TYPE_CODE_REF:
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case TYPE_CODE_ENUM:
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case TYPE_CODE_FLAGS:
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case TYPE_CODE_FUNC:
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case TYPE_CODE_METHOD:
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case TYPE_CODE_BOOL:
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case TYPE_CODE_RANGE:
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case TYPE_CODE_FLT:
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case TYPE_CODE_DECFLOAT:
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case TYPE_CODE_VOID:
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case TYPE_CODE_ERROR:
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case TYPE_CODE_UNDEF:
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case TYPE_CODE_COMPLEX:
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case TYPE_CODE_CHAR:
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default:
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generic_val_print (type, valaddr, embedded_offset, address,
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stream, recurse, original_value, options,
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&c_decorations);
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break;
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}
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gdb_flush (stream);
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}
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void
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c_value_print (struct value *val, struct ui_file *stream,
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const struct value_print_options *options)
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{
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struct type *type, *real_type, *val_type;
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int full, top, using_enc;
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struct value_print_options opts = *options;
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opts.deref_ref = 1;
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/* If it is a pointer, indicate what it points to.
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Print type also if it is a reference.
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C++: if it is a member pointer, we will take care
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of that when we print it. */
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/* Preserve the original type before stripping typedefs. We prefer
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to pass down the original type when possible, but for local
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checks it is better to look past the typedefs. */
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val_type = value_type (val);
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type = check_typedef (val_type);
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if (TYPE_CODE (type) == TYPE_CODE_PTR
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|| TYPE_CODE (type) == TYPE_CODE_REF)
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{
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/* Hack: remove (char *) for char strings. Their
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type is indicated by the quoted string anyway.
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(Don't use c_textual_element_type here; quoted strings
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are always exactly (char *), (wchar_t *), or the like. */
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if (TYPE_CODE (val_type) == TYPE_CODE_PTR
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&& TYPE_NAME (val_type) == NULL
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&& TYPE_NAME (TYPE_TARGET_TYPE (val_type)) != NULL
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&& (strcmp (TYPE_NAME (TYPE_TARGET_TYPE (val_type)),
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"char") == 0
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|| textual_name (TYPE_NAME (TYPE_TARGET_TYPE (val_type)))))
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{
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/* Print nothing. */
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}
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else if (options->objectprint
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&& (TYPE_CODE (TYPE_TARGET_TYPE (type)) == TYPE_CODE_CLASS))
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{
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int is_ref = TYPE_CODE (type) == TYPE_CODE_REF;
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if (is_ref)
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val = value_addr (val);
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/* Pointer to class, check real type of object. */
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fprintf_filtered (stream, "(");
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if (value_entirely_available (val))
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{
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real_type = value_rtti_indirect_type (val, &full, &top,
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&using_enc);
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if (real_type)
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{
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/* RTTI entry found. */
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type = real_type;
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/* Need to adjust pointer value. */
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val = value_from_pointer (real_type,
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value_as_address (val) - top);
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if (is_ref)
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{
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val = value_ref (value_ind (val));
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type = value_type (val);
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}
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/* Note: When we look up RTTI entries, we don't get
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any information on const or volatile
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attributes. */
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}
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}
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type_print (type, "", stream, -1);
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fprintf_filtered (stream, ") ");
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val_type = type;
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}
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else
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{
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/* normal case */
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fprintf_filtered (stream, "(");
|
||
type_print (value_type (val), "", stream, -1);
|
||
fprintf_filtered (stream, ") ");
|
||
}
|
||
}
|
||
|
||
if (!value_initialized (val))
|
||
fprintf_filtered (stream, " [uninitialized] ");
|
||
|
||
if (options->objectprint && (TYPE_CODE (type) == TYPE_CODE_CLASS))
|
||
{
|
||
/* Attempt to determine real type of object. */
|
||
real_type = value_rtti_type (val, &full, &top, &using_enc);
|
||
if (real_type)
|
||
{
|
||
/* We have RTTI information, so use it. */
|
||
val = value_full_object (val, real_type,
|
||
full, top, using_enc);
|
||
fprintf_filtered (stream, "(%s%s) ",
|
||
TYPE_NAME (real_type),
|
||
full ? "" : _(" [incomplete object]"));
|
||
/* Print out object: enclosing type is same as real_type if
|
||
full. */
|
||
val_print (value_enclosing_type (val),
|
||
value_contents_for_printing (val), 0,
|
||
value_address (val), stream, 0,
|
||
val, &opts, current_language);
|
||
return;
|
||
/* Note: When we look up RTTI entries, we don't get any
|
||
information on const or volatile attributes. */
|
||
}
|
||
else if (type != check_typedef (value_enclosing_type (val)))
|
||
{
|
||
/* No RTTI information, so let's do our best. */
|
||
fprintf_filtered (stream, "(%s ?) ",
|
||
TYPE_NAME (value_enclosing_type (val)));
|
||
val_print (value_enclosing_type (val),
|
||
value_contents_for_printing (val), 0,
|
||
value_address (val), stream, 0,
|
||
val, &opts, current_language);
|
||
return;
|
||
}
|
||
/* Otherwise, we end up at the return outside this "if". */
|
||
}
|
||
|
||
val_print (val_type, value_contents_for_printing (val),
|
||
value_embedded_offset (val),
|
||
value_address (val),
|
||
stream, 0,
|
||
val, &opts, current_language);
|
||
}
|