2353 lines
66 KiB
C
2353 lines
66 KiB
C
/* Low level packing and unpacking of values for GDB, the GNU Debugger.
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Copyright (C) 1986, 1987, 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995,
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1996, 1997, 1998, 1999, 2000, 2002, 2003, 2004, 2005, 2006, 2007, 2008,
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2009, 2010 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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||
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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 "arch-utils.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 "value.h"
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#include "gdbcore.h"
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#include "command.h"
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#include "gdbcmd.h"
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#include "target.h"
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#include "language.h"
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#include "demangle.h"
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#include "doublest.h"
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#include "gdb_assert.h"
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#include "regcache.h"
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#include "block.h"
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#include "dfp.h"
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#include "objfiles.h"
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#include "valprint.h"
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#include "cli/cli-decode.h"
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#include "python/python.h"
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/* Prototypes for exported functions. */
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void _initialize_values (void);
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/* Definition of a user function. */
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struct internal_function
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{
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/* The name of the function. It is a bit odd to have this in the
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function itself -- the user might use a differently-named
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convenience variable to hold the function. */
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char *name;
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/* The handler. */
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internal_function_fn handler;
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/* User data for the handler. */
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void *cookie;
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};
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static struct cmd_list_element *functionlist;
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struct value
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{
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/* Type of value; either not an lval, or one of the various
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different possible kinds of lval. */
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enum lval_type lval;
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/* Is it modifiable? Only relevant if lval != not_lval. */
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int modifiable;
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/* Location of value (if lval). */
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union
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{
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/* If lval == lval_memory, this is the address in the inferior.
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If lval == lval_register, this is the byte offset into the
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registers structure. */
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CORE_ADDR address;
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/* Pointer to internal variable. */
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struct internalvar *internalvar;
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/* If lval == lval_computed, this is a set of function pointers
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to use to access and describe the value, and a closure pointer
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for them to use. */
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struct
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{
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struct lval_funcs *funcs; /* Functions to call. */
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void *closure; /* Closure for those functions to use. */
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} computed;
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} location;
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/* Describes offset of a value within lval of a structure in bytes.
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If lval == lval_memory, this is an offset to the address. If
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lval == lval_register, this is a further offset from
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location.address within the registers structure. Note also the
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member embedded_offset below. */
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int offset;
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/* Only used for bitfields; number of bits contained in them. */
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int bitsize;
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/* Only used for bitfields; position of start of field. For
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gdbarch_bits_big_endian=0 targets, it is the position of the LSB. For
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gdbarch_bits_big_endian=1 targets, it is the position of the MSB. */
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int bitpos;
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/* Only used for bitfields; the containing value. This allows a
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single read from the target when displaying multiple
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bitfields. */
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struct value *parent;
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/* Frame register value is relative to. This will be described in
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the lval enum above as "lval_register". */
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struct frame_id frame_id;
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/* Type of the value. */
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struct type *type;
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/* If a value represents a C++ object, then the `type' field gives
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the object's compile-time type. If the object actually belongs
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to some class derived from `type', perhaps with other base
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classes and additional members, then `type' is just a subobject
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of the real thing, and the full object is probably larger than
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`type' would suggest.
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If `type' is a dynamic class (i.e. one with a vtable), then GDB
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can actually determine the object's run-time type by looking at
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the run-time type information in the vtable. When this
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information is available, we may elect to read in the entire
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object, for several reasons:
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- When printing the value, the user would probably rather see the
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full object, not just the limited portion apparent from the
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compile-time type.
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- If `type' has virtual base classes, then even printing `type'
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alone may require reaching outside the `type' portion of the
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object to wherever the virtual base class has been stored.
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When we store the entire object, `enclosing_type' is the run-time
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type -- the complete object -- and `embedded_offset' is the
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offset of `type' within that larger type, in bytes. The
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value_contents() macro takes `embedded_offset' into account, so
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most GDB code continues to see the `type' portion of the value,
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just as the inferior would.
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If `type' is a pointer to an object, then `enclosing_type' is a
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pointer to the object's run-time type, and `pointed_to_offset' is
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the offset in bytes from the full object to the pointed-to object
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-- that is, the value `embedded_offset' would have if we followed
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the pointer and fetched the complete object. (I don't really see
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the point. Why not just determine the run-time type when you
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indirect, and avoid the special case? The contents don't matter
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until you indirect anyway.)
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If we're not doing anything fancy, `enclosing_type' is equal to
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`type', and `embedded_offset' is zero, so everything works
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normally. */
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struct type *enclosing_type;
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int embedded_offset;
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int pointed_to_offset;
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/* Values are stored in a chain, so that they can be deleted easily
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over calls to the inferior. Values assigned to internal
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variables, put into the value history or exposed to Python are
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taken off this list. */
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struct value *next;
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/* Register number if the value is from a register. */
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short regnum;
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/* If zero, contents of this value are in the contents field. If
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nonzero, contents are in inferior. If the lval field is lval_memory,
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the contents are in inferior memory at location.address plus offset.
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The lval field may also be lval_register.
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WARNING: This field is used by the code which handles watchpoints
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(see breakpoint.c) to decide whether a particular value can be
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watched by hardware watchpoints. If the lazy flag is set for
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some member of a value chain, it is assumed that this member of
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the chain doesn't need to be watched as part of watching the
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value itself. This is how GDB avoids watching the entire struct
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or array when the user wants to watch a single struct member or
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array element. If you ever change the way lazy flag is set and
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reset, be sure to consider this use as well! */
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char lazy;
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/* If nonzero, this is the value of a variable which does not
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actually exist in the program. */
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char optimized_out;
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/* If value is a variable, is it initialized or not. */
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int initialized;
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/* If value is from the stack. If this is set, read_stack will be
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used instead of read_memory to enable extra caching. */
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int stack;
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/* Actual contents of the value. Target byte-order. NULL or not
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valid if lazy is nonzero. */
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gdb_byte *contents;
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/* The number of references to this value. When a value is created,
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the value chain holds a reference, so REFERENCE_COUNT is 1. If
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release_value is called, this value is removed from the chain but
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the caller of release_value now has a reference to this value.
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The caller must arrange for a call to value_free later. */
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int reference_count;
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};
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/* Prototypes for local functions. */
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static void show_values (char *, int);
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static void show_convenience (char *, int);
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/* The value-history records all the values printed
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by print commands during this session. Each chunk
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records 60 consecutive values. The first chunk on
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the chain records the most recent values.
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The total number of values is in value_history_count. */
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#define VALUE_HISTORY_CHUNK 60
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struct value_history_chunk
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{
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struct value_history_chunk *next;
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struct value *values[VALUE_HISTORY_CHUNK];
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};
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/* Chain of chunks now in use. */
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static struct value_history_chunk *value_history_chain;
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static int value_history_count; /* Abs number of last entry stored */
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/* List of all value objects currently allocated
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(except for those released by calls to release_value)
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This is so they can be freed after each command. */
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static struct value *all_values;
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/* Allocate a lazy value for type TYPE. Its actual content is
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"lazily" allocated too: the content field of the return value is
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NULL; it will be allocated when it is fetched from the target. */
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struct value *
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allocate_value_lazy (struct type *type)
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{
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struct value *val;
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struct type *atype = check_typedef (type);
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val = (struct value *) xzalloc (sizeof (struct value));
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val->contents = NULL;
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val->next = all_values;
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all_values = val;
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val->type = type;
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val->enclosing_type = type;
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VALUE_LVAL (val) = not_lval;
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val->location.address = 0;
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VALUE_FRAME_ID (val) = null_frame_id;
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val->offset = 0;
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val->bitpos = 0;
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val->bitsize = 0;
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VALUE_REGNUM (val) = -1;
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val->lazy = 1;
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val->optimized_out = 0;
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val->embedded_offset = 0;
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val->pointed_to_offset = 0;
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val->modifiable = 1;
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val->initialized = 1; /* Default to initialized. */
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/* Values start out on the all_values chain. */
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val->reference_count = 1;
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return val;
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}
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/* Allocate the contents of VAL if it has not been allocated yet. */
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void
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allocate_value_contents (struct value *val)
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{
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if (!val->contents)
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val->contents = (gdb_byte *) xzalloc (TYPE_LENGTH (val->enclosing_type));
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}
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/* Allocate a value and its contents for type TYPE. */
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struct value *
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allocate_value (struct type *type)
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{
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struct value *val = allocate_value_lazy (type);
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allocate_value_contents (val);
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val->lazy = 0;
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return val;
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}
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/* Allocate a value that has the correct length
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for COUNT repetitions of type TYPE. */
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struct value *
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allocate_repeat_value (struct type *type, int count)
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{
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int low_bound = current_language->string_lower_bound; /* ??? */
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/* FIXME-type-allocation: need a way to free this type when we are
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done with it. */
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struct type *array_type
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= lookup_array_range_type (type, low_bound, count + low_bound - 1);
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return allocate_value (array_type);
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}
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struct value *
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allocate_computed_value (struct type *type,
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struct lval_funcs *funcs,
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void *closure)
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{
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struct value *v = allocate_value (type);
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VALUE_LVAL (v) = lval_computed;
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v->location.computed.funcs = funcs;
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v->location.computed.closure = closure;
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set_value_lazy (v, 1);
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return v;
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}
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/* Accessor methods. */
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struct value *
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value_next (struct value *value)
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{
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return value->next;
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}
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struct type *
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value_type (struct value *value)
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{
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return value->type;
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}
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void
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deprecated_set_value_type (struct value *value, struct type *type)
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{
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value->type = type;
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}
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int
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value_offset (struct value *value)
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{
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return value->offset;
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}
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void
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set_value_offset (struct value *value, int offset)
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{
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value->offset = offset;
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}
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int
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value_bitpos (struct value *value)
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{
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return value->bitpos;
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}
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void
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set_value_bitpos (struct value *value, int bit)
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{
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value->bitpos = bit;
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}
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int
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value_bitsize (struct value *value)
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||
{
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return value->bitsize;
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}
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void
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set_value_bitsize (struct value *value, int bit)
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{
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value->bitsize = bit;
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}
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struct value *
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value_parent (struct value *value)
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{
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return value->parent;
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}
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gdb_byte *
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value_contents_raw (struct value *value)
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||
{
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allocate_value_contents (value);
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return value->contents + value->embedded_offset;
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}
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||
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gdb_byte *
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value_contents_all_raw (struct value *value)
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||
{
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allocate_value_contents (value);
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return value->contents;
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||
}
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||
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struct type *
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value_enclosing_type (struct value *value)
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{
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return value->enclosing_type;
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}
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const gdb_byte *
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value_contents_all (struct value *value)
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||
{
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if (value->lazy)
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value_fetch_lazy (value);
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return value->contents;
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||
}
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||
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int
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value_lazy (struct value *value)
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{
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return value->lazy;
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||
}
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||
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void
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set_value_lazy (struct value *value, int val)
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||
{
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value->lazy = val;
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||
}
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||
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||
int
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value_stack (struct value *value)
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||
{
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||
return value->stack;
|
||
}
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||
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||
void
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||
set_value_stack (struct value *value, int val)
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||
{
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value->stack = val;
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||
}
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||
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||
const gdb_byte *
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||
value_contents (struct value *value)
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||
{
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||
return value_contents_writeable (value);
|
||
}
|
||
|
||
gdb_byte *
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||
value_contents_writeable (struct value *value)
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||
{
|
||
if (value->lazy)
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||
value_fetch_lazy (value);
|
||
return value_contents_raw (value);
|
||
}
|
||
|
||
/* Return non-zero if VAL1 and VAL2 have the same contents. Note that
|
||
this function is different from value_equal; in C the operator ==
|
||
can return 0 even if the two values being compared are equal. */
|
||
|
||
int
|
||
value_contents_equal (struct value *val1, struct value *val2)
|
||
{
|
||
struct type *type1;
|
||
struct type *type2;
|
||
int len;
|
||
|
||
type1 = check_typedef (value_type (val1));
|
||
type2 = check_typedef (value_type (val2));
|
||
len = TYPE_LENGTH (type1);
|
||
if (len != TYPE_LENGTH (type2))
|
||
return 0;
|
||
|
||
return (memcmp (value_contents (val1), value_contents (val2), len) == 0);
|
||
}
|
||
|
||
int
|
||
value_optimized_out (struct value *value)
|
||
{
|
||
return value->optimized_out;
|
||
}
|
||
|
||
void
|
||
set_value_optimized_out (struct value *value, int val)
|
||
{
|
||
value->optimized_out = val;
|
||
}
|
||
|
||
int
|
||
value_embedded_offset (struct value *value)
|
||
{
|
||
return value->embedded_offset;
|
||
}
|
||
|
||
void
|
||
set_value_embedded_offset (struct value *value, int val)
|
||
{
|
||
value->embedded_offset = val;
|
||
}
|
||
|
||
int
|
||
value_pointed_to_offset (struct value *value)
|
||
{
|
||
return value->pointed_to_offset;
|
||
}
|
||
|
||
void
|
||
set_value_pointed_to_offset (struct value *value, int val)
|
||
{
|
||
value->pointed_to_offset = val;
|
||
}
|
||
|
||
struct lval_funcs *
|
||
value_computed_funcs (struct value *v)
|
||
{
|
||
gdb_assert (VALUE_LVAL (v) == lval_computed);
|
||
|
||
return v->location.computed.funcs;
|
||
}
|
||
|
||
void *
|
||
value_computed_closure (struct value *v)
|
||
{
|
||
gdb_assert (VALUE_LVAL (v) == lval_computed);
|
||
|
||
return v->location.computed.closure;
|
||
}
|
||
|
||
enum lval_type *
|
||
deprecated_value_lval_hack (struct value *value)
|
||
{
|
||
return &value->lval;
|
||
}
|
||
|
||
CORE_ADDR
|
||
value_address (struct value *value)
|
||
{
|
||
if (value->lval == lval_internalvar
|
||
|| value->lval == lval_internalvar_component)
|
||
return 0;
|
||
return value->location.address + value->offset;
|
||
}
|
||
|
||
CORE_ADDR
|
||
value_raw_address (struct value *value)
|
||
{
|
||
if (value->lval == lval_internalvar
|
||
|| value->lval == lval_internalvar_component)
|
||
return 0;
|
||
return value->location.address;
|
||
}
|
||
|
||
void
|
||
set_value_address (struct value *value, CORE_ADDR addr)
|
||
{
|
||
gdb_assert (value->lval != lval_internalvar
|
||
&& value->lval != lval_internalvar_component);
|
||
value->location.address = addr;
|
||
}
|
||
|
||
struct internalvar **
|
||
deprecated_value_internalvar_hack (struct value *value)
|
||
{
|
||
return &value->location.internalvar;
|
||
}
|
||
|
||
struct frame_id *
|
||
deprecated_value_frame_id_hack (struct value *value)
|
||
{
|
||
return &value->frame_id;
|
||
}
|
||
|
||
short *
|
||
deprecated_value_regnum_hack (struct value *value)
|
||
{
|
||
return &value->regnum;
|
||
}
|
||
|
||
int
|
||
deprecated_value_modifiable (struct value *value)
|
||
{
|
||
return value->modifiable;
|
||
}
|
||
void
|
||
deprecated_set_value_modifiable (struct value *value, int modifiable)
|
||
{
|
||
value->modifiable = modifiable;
|
||
}
|
||
|
||
/* Return a mark in the value chain. All values allocated after the
|
||
mark is obtained (except for those released) are subject to being freed
|
||
if a subsequent value_free_to_mark is passed the mark. */
|
||
struct value *
|
||
value_mark (void)
|
||
{
|
||
return all_values;
|
||
}
|
||
|
||
/* Take a reference to VAL. VAL will not be deallocated until all
|
||
references are released. */
|
||
|
||
void
|
||
value_incref (struct value *val)
|
||
{
|
||
val->reference_count++;
|
||
}
|
||
|
||
/* Release a reference to VAL, which was acquired with value_incref.
|
||
This function is also called to deallocate values from the value
|
||
chain. */
|
||
|
||
void
|
||
value_free (struct value *val)
|
||
{
|
||
if (val)
|
||
{
|
||
gdb_assert (val->reference_count > 0);
|
||
val->reference_count--;
|
||
if (val->reference_count > 0)
|
||
return;
|
||
|
||
/* If there's an associated parent value, drop our reference to
|
||
it. */
|
||
if (val->parent != NULL)
|
||
value_free (val->parent);
|
||
|
||
if (VALUE_LVAL (val) == lval_computed)
|
||
{
|
||
struct lval_funcs *funcs = val->location.computed.funcs;
|
||
|
||
if (funcs->free_closure)
|
||
funcs->free_closure (val);
|
||
}
|
||
|
||
xfree (val->contents);
|
||
}
|
||
xfree (val);
|
||
}
|
||
|
||
/* Free all values allocated since MARK was obtained by value_mark
|
||
(except for those released). */
|
||
void
|
||
value_free_to_mark (struct value *mark)
|
||
{
|
||
struct value *val;
|
||
struct value *next;
|
||
|
||
for (val = all_values; val && val != mark; val = next)
|
||
{
|
||
next = val->next;
|
||
value_free (val);
|
||
}
|
||
all_values = val;
|
||
}
|
||
|
||
/* Free all the values that have been allocated (except for those released).
|
||
Call after each command, successful or not.
|
||
In practice this is called before each command, which is sufficient. */
|
||
|
||
void
|
||
free_all_values (void)
|
||
{
|
||
struct value *val;
|
||
struct value *next;
|
||
|
||
for (val = all_values; val; val = next)
|
||
{
|
||
next = val->next;
|
||
value_free (val);
|
||
}
|
||
|
||
all_values = 0;
|
||
}
|
||
|
||
/* Remove VAL from the chain all_values
|
||
so it will not be freed automatically. */
|
||
|
||
void
|
||
release_value (struct value *val)
|
||
{
|
||
struct value *v;
|
||
|
||
if (all_values == val)
|
||
{
|
||
all_values = val->next;
|
||
return;
|
||
}
|
||
|
||
for (v = all_values; v; v = v->next)
|
||
{
|
||
if (v->next == val)
|
||
{
|
||
v->next = val->next;
|
||
break;
|
||
}
|
||
}
|
||
}
|
||
|
||
/* Release all values up to mark */
|
||
struct value *
|
||
value_release_to_mark (struct value *mark)
|
||
{
|
||
struct value *val;
|
||
struct value *next;
|
||
|
||
for (val = next = all_values; next; next = next->next)
|
||
if (next->next == mark)
|
||
{
|
||
all_values = next->next;
|
||
next->next = NULL;
|
||
return val;
|
||
}
|
||
all_values = 0;
|
||
return val;
|
||
}
|
||
|
||
/* Return a copy of the value ARG.
|
||
It contains the same contents, for same memory address,
|
||
but it's a different block of storage. */
|
||
|
||
struct value *
|
||
value_copy (struct value *arg)
|
||
{
|
||
struct type *encl_type = value_enclosing_type (arg);
|
||
struct value *val;
|
||
|
||
if (value_lazy (arg))
|
||
val = allocate_value_lazy (encl_type);
|
||
else
|
||
val = allocate_value (encl_type);
|
||
val->type = arg->type;
|
||
VALUE_LVAL (val) = VALUE_LVAL (arg);
|
||
val->location = arg->location;
|
||
val->offset = arg->offset;
|
||
val->bitpos = arg->bitpos;
|
||
val->bitsize = arg->bitsize;
|
||
VALUE_FRAME_ID (val) = VALUE_FRAME_ID (arg);
|
||
VALUE_REGNUM (val) = VALUE_REGNUM (arg);
|
||
val->lazy = arg->lazy;
|
||
val->optimized_out = arg->optimized_out;
|
||
val->embedded_offset = value_embedded_offset (arg);
|
||
val->pointed_to_offset = arg->pointed_to_offset;
|
||
val->modifiable = arg->modifiable;
|
||
if (!value_lazy (val))
|
||
{
|
||
memcpy (value_contents_all_raw (val), value_contents_all_raw (arg),
|
||
TYPE_LENGTH (value_enclosing_type (arg)));
|
||
|
||
}
|
||
val->parent = arg->parent;
|
||
if (val->parent)
|
||
value_incref (val->parent);
|
||
if (VALUE_LVAL (val) == lval_computed)
|
||
{
|
||
struct lval_funcs *funcs = val->location.computed.funcs;
|
||
|
||
if (funcs->copy_closure)
|
||
val->location.computed.closure = funcs->copy_closure (val);
|
||
}
|
||
return val;
|
||
}
|
||
|
||
void
|
||
set_value_component_location (struct value *component, struct value *whole)
|
||
{
|
||
if (VALUE_LVAL (whole) == lval_internalvar)
|
||
VALUE_LVAL (component) = lval_internalvar_component;
|
||
else
|
||
VALUE_LVAL (component) = VALUE_LVAL (whole);
|
||
|
||
component->location = whole->location;
|
||
if (VALUE_LVAL (whole) == lval_computed)
|
||
{
|
||
struct lval_funcs *funcs = whole->location.computed.funcs;
|
||
|
||
if (funcs->copy_closure)
|
||
component->location.computed.closure = funcs->copy_closure (whole);
|
||
}
|
||
}
|
||
|
||
|
||
/* Access to the value history. */
|
||
|
||
/* Record a new value in the value history.
|
||
Returns the absolute history index of the entry.
|
||
Result of -1 indicates the value was not saved; otherwise it is the
|
||
value history index of this new item. */
|
||
|
||
int
|
||
record_latest_value (struct value *val)
|
||
{
|
||
int i;
|
||
|
||
/* We don't want this value to have anything to do with the inferior anymore.
|
||
In particular, "set $1 = 50" should not affect the variable from which
|
||
the value was taken, and fast watchpoints should be able to assume that
|
||
a value on the value history never changes. */
|
||
if (value_lazy (val))
|
||
value_fetch_lazy (val);
|
||
/* We preserve VALUE_LVAL so that the user can find out where it was fetched
|
||
from. This is a bit dubious, because then *&$1 does not just return $1
|
||
but the current contents of that location. c'est la vie... */
|
||
val->modifiable = 0;
|
||
release_value (val);
|
||
|
||
/* Here we treat value_history_count as origin-zero
|
||
and applying to the value being stored now. */
|
||
|
||
i = value_history_count % VALUE_HISTORY_CHUNK;
|
||
if (i == 0)
|
||
{
|
||
struct value_history_chunk *new
|
||
= (struct value_history_chunk *)
|
||
xmalloc (sizeof (struct value_history_chunk));
|
||
memset (new->values, 0, sizeof new->values);
|
||
new->next = value_history_chain;
|
||
value_history_chain = new;
|
||
}
|
||
|
||
value_history_chain->values[i] = val;
|
||
|
||
/* Now we regard value_history_count as origin-one
|
||
and applying to the value just stored. */
|
||
|
||
return ++value_history_count;
|
||
}
|
||
|
||
/* Return a copy of the value in the history with sequence number NUM. */
|
||
|
||
struct value *
|
||
access_value_history (int num)
|
||
{
|
||
struct value_history_chunk *chunk;
|
||
int i;
|
||
int absnum = num;
|
||
|
||
if (absnum <= 0)
|
||
absnum += value_history_count;
|
||
|
||
if (absnum <= 0)
|
||
{
|
||
if (num == 0)
|
||
error (_("The history is empty."));
|
||
else if (num == 1)
|
||
error (_("There is only one value in the history."));
|
||
else
|
||
error (_("History does not go back to $$%d."), -num);
|
||
}
|
||
if (absnum > value_history_count)
|
||
error (_("History has not yet reached $%d."), absnum);
|
||
|
||
absnum--;
|
||
|
||
/* Now absnum is always absolute and origin zero. */
|
||
|
||
chunk = value_history_chain;
|
||
for (i = (value_history_count - 1) / VALUE_HISTORY_CHUNK - absnum / VALUE_HISTORY_CHUNK;
|
||
i > 0; i--)
|
||
chunk = chunk->next;
|
||
|
||
return value_copy (chunk->values[absnum % VALUE_HISTORY_CHUNK]);
|
||
}
|
||
|
||
static void
|
||
show_values (char *num_exp, int from_tty)
|
||
{
|
||
int i;
|
||
struct value *val;
|
||
static int num = 1;
|
||
|
||
if (num_exp)
|
||
{
|
||
/* "show values +" should print from the stored position.
|
||
"show values <exp>" should print around value number <exp>. */
|
||
if (num_exp[0] != '+' || num_exp[1] != '\0')
|
||
num = parse_and_eval_long (num_exp) - 5;
|
||
}
|
||
else
|
||
{
|
||
/* "show values" means print the last 10 values. */
|
||
num = value_history_count - 9;
|
||
}
|
||
|
||
if (num <= 0)
|
||
num = 1;
|
||
|
||
for (i = num; i < num + 10 && i <= value_history_count; i++)
|
||
{
|
||
struct value_print_options opts;
|
||
val = access_value_history (i);
|
||
printf_filtered (("$%d = "), i);
|
||
get_user_print_options (&opts);
|
||
value_print (val, gdb_stdout, &opts);
|
||
printf_filtered (("\n"));
|
||
}
|
||
|
||
/* The next "show values +" should start after what we just printed. */
|
||
num += 10;
|
||
|
||
/* Hitting just return after this command should do the same thing as
|
||
"show values +". If num_exp is null, this is unnecessary, since
|
||
"show values +" is not useful after "show values". */
|
||
if (from_tty && num_exp)
|
||
{
|
||
num_exp[0] = '+';
|
||
num_exp[1] = '\0';
|
||
}
|
||
}
|
||
|
||
/* Internal variables. These are variables within the debugger
|
||
that hold values assigned by debugger commands.
|
||
The user refers to them with a '$' prefix
|
||
that does not appear in the variable names stored internally. */
|
||
|
||
struct internalvar
|
||
{
|
||
struct internalvar *next;
|
||
char *name;
|
||
|
||
/* We support various different kinds of content of an internal variable.
|
||
enum internalvar_kind specifies the kind, and union internalvar_data
|
||
provides the data associated with this particular kind. */
|
||
|
||
enum internalvar_kind
|
||
{
|
||
/* The internal variable is empty. */
|
||
INTERNALVAR_VOID,
|
||
|
||
/* The value of the internal variable is provided directly as
|
||
a GDB value object. */
|
||
INTERNALVAR_VALUE,
|
||
|
||
/* A fresh value is computed via a call-back routine on every
|
||
access to the internal variable. */
|
||
INTERNALVAR_MAKE_VALUE,
|
||
|
||
/* The internal variable holds a GDB internal convenience function. */
|
||
INTERNALVAR_FUNCTION,
|
||
|
||
/* The variable holds an integer value. */
|
||
INTERNALVAR_INTEGER,
|
||
|
||
/* The variable holds a pointer value. */
|
||
INTERNALVAR_POINTER,
|
||
|
||
/* The variable holds a GDB-provided string. */
|
||
INTERNALVAR_STRING,
|
||
|
||
} kind;
|
||
|
||
union internalvar_data
|
||
{
|
||
/* A value object used with INTERNALVAR_VALUE. */
|
||
struct value *value;
|
||
|
||
/* The call-back routine used with INTERNALVAR_MAKE_VALUE. */
|
||
internalvar_make_value make_value;
|
||
|
||
/* The internal function used with INTERNALVAR_FUNCTION. */
|
||
struct
|
||
{
|
||
struct internal_function *function;
|
||
/* True if this is the canonical name for the function. */
|
||
int canonical;
|
||
} fn;
|
||
|
||
/* An integer value used with INTERNALVAR_INTEGER. */
|
||
struct
|
||
{
|
||
/* If type is non-NULL, it will be used as the type to generate
|
||
a value for this internal variable. If type is NULL, a default
|
||
integer type for the architecture is used. */
|
||
struct type *type;
|
||
LONGEST val;
|
||
} integer;
|
||
|
||
/* A pointer value used with INTERNALVAR_POINTER. */
|
||
struct
|
||
{
|
||
struct type *type;
|
||
CORE_ADDR val;
|
||
} pointer;
|
||
|
||
/* A string value used with INTERNALVAR_STRING. */
|
||
char *string;
|
||
} u;
|
||
};
|
||
|
||
static struct internalvar *internalvars;
|
||
|
||
/* If the variable does not already exist create it and give it the value given.
|
||
If no value is given then the default is zero. */
|
||
static void
|
||
init_if_undefined_command (char* args, int from_tty)
|
||
{
|
||
struct internalvar* intvar;
|
||
|
||
/* Parse the expression - this is taken from set_command(). */
|
||
struct expression *expr = parse_expression (args);
|
||
register struct cleanup *old_chain =
|
||
make_cleanup (free_current_contents, &expr);
|
||
|
||
/* Validate the expression.
|
||
Was the expression an assignment?
|
||
Or even an expression at all? */
|
||
if (expr->nelts == 0 || expr->elts[0].opcode != BINOP_ASSIGN)
|
||
error (_("Init-if-undefined requires an assignment expression."));
|
||
|
||
/* Extract the variable from the parsed expression.
|
||
In the case of an assign the lvalue will be in elts[1] and elts[2]. */
|
||
if (expr->elts[1].opcode != OP_INTERNALVAR)
|
||
error (_("The first parameter to init-if-undefined should be a GDB variable."));
|
||
intvar = expr->elts[2].internalvar;
|
||
|
||
/* Only evaluate the expression if the lvalue is void.
|
||
This may still fail if the expresssion is invalid. */
|
||
if (intvar->kind == INTERNALVAR_VOID)
|
||
evaluate_expression (expr);
|
||
|
||
do_cleanups (old_chain);
|
||
}
|
||
|
||
|
||
/* Look up an internal variable with name NAME. NAME should not
|
||
normally include a dollar sign.
|
||
|
||
If the specified internal variable does not exist,
|
||
the return value is NULL. */
|
||
|
||
struct internalvar *
|
||
lookup_only_internalvar (const char *name)
|
||
{
|
||
struct internalvar *var;
|
||
|
||
for (var = internalvars; var; var = var->next)
|
||
if (strcmp (var->name, name) == 0)
|
||
return var;
|
||
|
||
return NULL;
|
||
}
|
||
|
||
|
||
/* Create an internal variable with name NAME and with a void value.
|
||
NAME should not normally include a dollar sign. */
|
||
|
||
struct internalvar *
|
||
create_internalvar (const char *name)
|
||
{
|
||
struct internalvar *var;
|
||
var = (struct internalvar *) xmalloc (sizeof (struct internalvar));
|
||
var->name = concat (name, (char *)NULL);
|
||
var->kind = INTERNALVAR_VOID;
|
||
var->next = internalvars;
|
||
internalvars = var;
|
||
return var;
|
||
}
|
||
|
||
/* Create an internal variable with name NAME and register FUN as the
|
||
function that value_of_internalvar uses to create a value whenever
|
||
this variable is referenced. NAME should not normally include a
|
||
dollar sign. */
|
||
|
||
struct internalvar *
|
||
create_internalvar_type_lazy (char *name, internalvar_make_value fun)
|
||
{
|
||
struct internalvar *var = create_internalvar (name);
|
||
var->kind = INTERNALVAR_MAKE_VALUE;
|
||
var->u.make_value = fun;
|
||
return var;
|
||
}
|
||
|
||
/* Look up an internal variable with name NAME. NAME should not
|
||
normally include a dollar sign.
|
||
|
||
If the specified internal variable does not exist,
|
||
one is created, with a void value. */
|
||
|
||
struct internalvar *
|
||
lookup_internalvar (const char *name)
|
||
{
|
||
struct internalvar *var;
|
||
|
||
var = lookup_only_internalvar (name);
|
||
if (var)
|
||
return var;
|
||
|
||
return create_internalvar (name);
|
||
}
|
||
|
||
/* Return current value of internal variable VAR. For variables that
|
||
are not inherently typed, use a value type appropriate for GDBARCH. */
|
||
|
||
struct value *
|
||
value_of_internalvar (struct gdbarch *gdbarch, struct internalvar *var)
|
||
{
|
||
struct value *val;
|
||
|
||
switch (var->kind)
|
||
{
|
||
case INTERNALVAR_VOID:
|
||
val = allocate_value (builtin_type (gdbarch)->builtin_void);
|
||
break;
|
||
|
||
case INTERNALVAR_FUNCTION:
|
||
val = allocate_value (builtin_type (gdbarch)->internal_fn);
|
||
break;
|
||
|
||
case INTERNALVAR_INTEGER:
|
||
if (!var->u.integer.type)
|
||
val = value_from_longest (builtin_type (gdbarch)->builtin_int,
|
||
var->u.integer.val);
|
||
else
|
||
val = value_from_longest (var->u.integer.type, var->u.integer.val);
|
||
break;
|
||
|
||
case INTERNALVAR_POINTER:
|
||
val = value_from_pointer (var->u.pointer.type, var->u.pointer.val);
|
||
break;
|
||
|
||
case INTERNALVAR_STRING:
|
||
val = value_cstring (var->u.string, strlen (var->u.string),
|
||
builtin_type (gdbarch)->builtin_char);
|
||
break;
|
||
|
||
case INTERNALVAR_VALUE:
|
||
val = value_copy (var->u.value);
|
||
if (value_lazy (val))
|
||
value_fetch_lazy (val);
|
||
break;
|
||
|
||
case INTERNALVAR_MAKE_VALUE:
|
||
val = (*var->u.make_value) (gdbarch, var);
|
||
break;
|
||
|
||
default:
|
||
internal_error (__FILE__, __LINE__, "bad kind");
|
||
}
|
||
|
||
/* Change the VALUE_LVAL to lval_internalvar so that future operations
|
||
on this value go back to affect the original internal variable.
|
||
|
||
Do not do this for INTERNALVAR_MAKE_VALUE variables, as those have
|
||
no underlying modifyable state in the internal variable.
|
||
|
||
Likewise, if the variable's value is a computed lvalue, we want
|
||
references to it to produce another computed lvalue, where
|
||
references and assignments actually operate through the
|
||
computed value's functions.
|
||
|
||
This means that internal variables with computed values
|
||
behave a little differently from other internal variables:
|
||
assignments to them don't just replace the previous value
|
||
altogether. At the moment, this seems like the behavior we
|
||
want. */
|
||
|
||
if (var->kind != INTERNALVAR_MAKE_VALUE
|
||
&& val->lval != lval_computed)
|
||
{
|
||
VALUE_LVAL (val) = lval_internalvar;
|
||
VALUE_INTERNALVAR (val) = var;
|
||
}
|
||
|
||
return val;
|
||
}
|
||
|
||
int
|
||
get_internalvar_integer (struct internalvar *var, LONGEST *result)
|
||
{
|
||
switch (var->kind)
|
||
{
|
||
case INTERNALVAR_INTEGER:
|
||
*result = var->u.integer.val;
|
||
return 1;
|
||
|
||
default:
|
||
return 0;
|
||
}
|
||
}
|
||
|
||
static int
|
||
get_internalvar_function (struct internalvar *var,
|
||
struct internal_function **result)
|
||
{
|
||
switch (var->kind)
|
||
{
|
||
case INTERNALVAR_FUNCTION:
|
||
*result = var->u.fn.function;
|
||
return 1;
|
||
|
||
default:
|
||
return 0;
|
||
}
|
||
}
|
||
|
||
void
|
||
set_internalvar_component (struct internalvar *var, int offset, int bitpos,
|
||
int bitsize, struct value *newval)
|
||
{
|
||
gdb_byte *addr;
|
||
|
||
switch (var->kind)
|
||
{
|
||
case INTERNALVAR_VALUE:
|
||
addr = value_contents_writeable (var->u.value);
|
||
|
||
if (bitsize)
|
||
modify_field (value_type (var->u.value), addr + offset,
|
||
value_as_long (newval), bitpos, bitsize);
|
||
else
|
||
memcpy (addr + offset, value_contents (newval),
|
||
TYPE_LENGTH (value_type (newval)));
|
||
break;
|
||
|
||
default:
|
||
/* We can never get a component of any other kind. */
|
||
internal_error (__FILE__, __LINE__, "set_internalvar_component");
|
||
}
|
||
}
|
||
|
||
void
|
||
set_internalvar (struct internalvar *var, struct value *val)
|
||
{
|
||
enum internalvar_kind new_kind;
|
||
union internalvar_data new_data = { 0 };
|
||
|
||
if (var->kind == INTERNALVAR_FUNCTION && var->u.fn.canonical)
|
||
error (_("Cannot overwrite convenience function %s"), var->name);
|
||
|
||
/* Prepare new contents. */
|
||
switch (TYPE_CODE (check_typedef (value_type (val))))
|
||
{
|
||
case TYPE_CODE_VOID:
|
||
new_kind = INTERNALVAR_VOID;
|
||
break;
|
||
|
||
case TYPE_CODE_INTERNAL_FUNCTION:
|
||
gdb_assert (VALUE_LVAL (val) == lval_internalvar);
|
||
new_kind = INTERNALVAR_FUNCTION;
|
||
get_internalvar_function (VALUE_INTERNALVAR (val),
|
||
&new_data.fn.function);
|
||
/* Copies created here are never canonical. */
|
||
break;
|
||
|
||
case TYPE_CODE_INT:
|
||
new_kind = INTERNALVAR_INTEGER;
|
||
new_data.integer.type = value_type (val);
|
||
new_data.integer.val = value_as_long (val);
|
||
break;
|
||
|
||
case TYPE_CODE_PTR:
|
||
new_kind = INTERNALVAR_POINTER;
|
||
new_data.pointer.type = value_type (val);
|
||
new_data.pointer.val = value_as_address (val);
|
||
break;
|
||
|
||
default:
|
||
new_kind = INTERNALVAR_VALUE;
|
||
new_data.value = value_copy (val);
|
||
new_data.value->modifiable = 1;
|
||
|
||
/* Force the value to be fetched from the target now, to avoid problems
|
||
later when this internalvar is referenced and the target is gone or
|
||
has changed. */
|
||
if (value_lazy (new_data.value))
|
||
value_fetch_lazy (new_data.value);
|
||
|
||
/* Release the value from the value chain to prevent it from being
|
||
deleted by free_all_values. From here on this function should not
|
||
call error () until new_data is installed into the var->u to avoid
|
||
leaking memory. */
|
||
release_value (new_data.value);
|
||
break;
|
||
}
|
||
|
||
/* Clean up old contents. */
|
||
clear_internalvar (var);
|
||
|
||
/* Switch over. */
|
||
var->kind = new_kind;
|
||
var->u = new_data;
|
||
/* End code which must not call error(). */
|
||
}
|
||
|
||
void
|
||
set_internalvar_integer (struct internalvar *var, LONGEST l)
|
||
{
|
||
/* Clean up old contents. */
|
||
clear_internalvar (var);
|
||
|
||
var->kind = INTERNALVAR_INTEGER;
|
||
var->u.integer.type = NULL;
|
||
var->u.integer.val = l;
|
||
}
|
||
|
||
void
|
||
set_internalvar_string (struct internalvar *var, const char *string)
|
||
{
|
||
/* Clean up old contents. */
|
||
clear_internalvar (var);
|
||
|
||
var->kind = INTERNALVAR_STRING;
|
||
var->u.string = xstrdup (string);
|
||
}
|
||
|
||
static void
|
||
set_internalvar_function (struct internalvar *var, struct internal_function *f)
|
||
{
|
||
/* Clean up old contents. */
|
||
clear_internalvar (var);
|
||
|
||
var->kind = INTERNALVAR_FUNCTION;
|
||
var->u.fn.function = f;
|
||
var->u.fn.canonical = 1;
|
||
/* Variables installed here are always the canonical version. */
|
||
}
|
||
|
||
void
|
||
clear_internalvar (struct internalvar *var)
|
||
{
|
||
/* Clean up old contents. */
|
||
switch (var->kind)
|
||
{
|
||
case INTERNALVAR_VALUE:
|
||
value_free (var->u.value);
|
||
break;
|
||
|
||
case INTERNALVAR_STRING:
|
||
xfree (var->u.string);
|
||
break;
|
||
|
||
default:
|
||
break;
|
||
}
|
||
|
||
/* Reset to void kind. */
|
||
var->kind = INTERNALVAR_VOID;
|
||
}
|
||
|
||
char *
|
||
internalvar_name (struct internalvar *var)
|
||
{
|
||
return var->name;
|
||
}
|
||
|
||
static struct internal_function *
|
||
create_internal_function (const char *name,
|
||
internal_function_fn handler, void *cookie)
|
||
{
|
||
struct internal_function *ifn = XNEW (struct internal_function);
|
||
ifn->name = xstrdup (name);
|
||
ifn->handler = handler;
|
||
ifn->cookie = cookie;
|
||
return ifn;
|
||
}
|
||
|
||
char *
|
||
value_internal_function_name (struct value *val)
|
||
{
|
||
struct internal_function *ifn;
|
||
int result;
|
||
|
||
gdb_assert (VALUE_LVAL (val) == lval_internalvar);
|
||
result = get_internalvar_function (VALUE_INTERNALVAR (val), &ifn);
|
||
gdb_assert (result);
|
||
|
||
return ifn->name;
|
||
}
|
||
|
||
struct value *
|
||
call_internal_function (struct gdbarch *gdbarch,
|
||
const struct language_defn *language,
|
||
struct value *func, int argc, struct value **argv)
|
||
{
|
||
struct internal_function *ifn;
|
||
int result;
|
||
|
||
gdb_assert (VALUE_LVAL (func) == lval_internalvar);
|
||
result = get_internalvar_function (VALUE_INTERNALVAR (func), &ifn);
|
||
gdb_assert (result);
|
||
|
||
return (*ifn->handler) (gdbarch, language, ifn->cookie, argc, argv);
|
||
}
|
||
|
||
/* The 'function' command. This does nothing -- it is just a
|
||
placeholder to let "help function NAME" work. This is also used as
|
||
the implementation of the sub-command that is created when
|
||
registering an internal function. */
|
||
static void
|
||
function_command (char *command, int from_tty)
|
||
{
|
||
/* Do nothing. */
|
||
}
|
||
|
||
/* Clean up if an internal function's command is destroyed. */
|
||
static void
|
||
function_destroyer (struct cmd_list_element *self, void *ignore)
|
||
{
|
||
xfree (self->name);
|
||
xfree (self->doc);
|
||
}
|
||
|
||
/* Add a new internal function. NAME is the name of the function; DOC
|
||
is a documentation string describing the function. HANDLER is
|
||
called when the function is invoked. COOKIE is an arbitrary
|
||
pointer which is passed to HANDLER and is intended for "user
|
||
data". */
|
||
void
|
||
add_internal_function (const char *name, const char *doc,
|
||
internal_function_fn handler, void *cookie)
|
||
{
|
||
struct cmd_list_element *cmd;
|
||
struct internal_function *ifn;
|
||
struct internalvar *var = lookup_internalvar (name);
|
||
|
||
ifn = create_internal_function (name, handler, cookie);
|
||
set_internalvar_function (var, ifn);
|
||
|
||
cmd = add_cmd (xstrdup (name), no_class, function_command, (char *) doc,
|
||
&functionlist);
|
||
cmd->destroyer = function_destroyer;
|
||
}
|
||
|
||
/* Update VALUE before discarding OBJFILE. COPIED_TYPES is used to
|
||
prevent cycles / duplicates. */
|
||
|
||
void
|
||
preserve_one_value (struct value *value, struct objfile *objfile,
|
||
htab_t copied_types)
|
||
{
|
||
if (TYPE_OBJFILE (value->type) == objfile)
|
||
value->type = copy_type_recursive (objfile, value->type, copied_types);
|
||
|
||
if (TYPE_OBJFILE (value->enclosing_type) == objfile)
|
||
value->enclosing_type = copy_type_recursive (objfile,
|
||
value->enclosing_type,
|
||
copied_types);
|
||
}
|
||
|
||
/* Likewise for internal variable VAR. */
|
||
|
||
static void
|
||
preserve_one_internalvar (struct internalvar *var, struct objfile *objfile,
|
||
htab_t copied_types)
|
||
{
|
||
switch (var->kind)
|
||
{
|
||
case INTERNALVAR_INTEGER:
|
||
if (var->u.integer.type && TYPE_OBJFILE (var->u.integer.type) == objfile)
|
||
var->u.integer.type
|
||
= copy_type_recursive (objfile, var->u.integer.type, copied_types);
|
||
break;
|
||
|
||
case INTERNALVAR_POINTER:
|
||
if (TYPE_OBJFILE (var->u.pointer.type) == objfile)
|
||
var->u.pointer.type
|
||
= copy_type_recursive (objfile, var->u.pointer.type, copied_types);
|
||
break;
|
||
|
||
case INTERNALVAR_VALUE:
|
||
preserve_one_value (var->u.value, objfile, copied_types);
|
||
break;
|
||
}
|
||
}
|
||
|
||
/* Update the internal variables and value history when OBJFILE is
|
||
discarded; we must copy the types out of the objfile. New global types
|
||
will be created for every convenience variable which currently points to
|
||
this objfile's types, and the convenience variables will be adjusted to
|
||
use the new global types. */
|
||
|
||
void
|
||
preserve_values (struct objfile *objfile)
|
||
{
|
||
htab_t copied_types;
|
||
struct value_history_chunk *cur;
|
||
struct internalvar *var;
|
||
struct value *val;
|
||
int i;
|
||
|
||
/* Create the hash table. We allocate on the objfile's obstack, since
|
||
it is soon to be deleted. */
|
||
copied_types = create_copied_types_hash (objfile);
|
||
|
||
for (cur = value_history_chain; cur; cur = cur->next)
|
||
for (i = 0; i < VALUE_HISTORY_CHUNK; i++)
|
||
if (cur->values[i])
|
||
preserve_one_value (cur->values[i], objfile, copied_types);
|
||
|
||
for (var = internalvars; var; var = var->next)
|
||
preserve_one_internalvar (var, objfile, copied_types);
|
||
|
||
preserve_python_values (objfile, copied_types);
|
||
|
||
htab_delete (copied_types);
|
||
}
|
||
|
||
static void
|
||
show_convenience (char *ignore, int from_tty)
|
||
{
|
||
struct gdbarch *gdbarch = get_current_arch ();
|
||
struct internalvar *var;
|
||
int varseen = 0;
|
||
struct value_print_options opts;
|
||
|
||
get_user_print_options (&opts);
|
||
for (var = internalvars; var; var = var->next)
|
||
{
|
||
if (!varseen)
|
||
{
|
||
varseen = 1;
|
||
}
|
||
printf_filtered (("$%s = "), var->name);
|
||
value_print (value_of_internalvar (gdbarch, var), gdb_stdout,
|
||
&opts);
|
||
printf_filtered (("\n"));
|
||
}
|
||
if (!varseen)
|
||
printf_unfiltered (_("\
|
||
No debugger convenience variables now defined.\n\
|
||
Convenience variables have names starting with \"$\";\n\
|
||
use \"set\" as in \"set $foo = 5\" to define them.\n"));
|
||
}
|
||
|
||
/* Extract a value as a C number (either long or double).
|
||
Knows how to convert fixed values to double, or
|
||
floating values to long.
|
||
Does not deallocate the value. */
|
||
|
||
LONGEST
|
||
value_as_long (struct value *val)
|
||
{
|
||
/* This coerces arrays and functions, which is necessary (e.g.
|
||
in disassemble_command). It also dereferences references, which
|
||
I suspect is the most logical thing to do. */
|
||
val = coerce_array (val);
|
||
return unpack_long (value_type (val), value_contents (val));
|
||
}
|
||
|
||
DOUBLEST
|
||
value_as_double (struct value *val)
|
||
{
|
||
DOUBLEST foo;
|
||
int inv;
|
||
|
||
foo = unpack_double (value_type (val), value_contents (val), &inv);
|
||
if (inv)
|
||
error (_("Invalid floating value found in program."));
|
||
return foo;
|
||
}
|
||
|
||
/* Extract a value as a C pointer. Does not deallocate the value.
|
||
Note that val's type may not actually be a pointer; value_as_long
|
||
handles all the cases. */
|
||
CORE_ADDR
|
||
value_as_address (struct value *val)
|
||
{
|
||
struct gdbarch *gdbarch = get_type_arch (value_type (val));
|
||
|
||
/* Assume a CORE_ADDR can fit in a LONGEST (for now). Not sure
|
||
whether we want this to be true eventually. */
|
||
#if 0
|
||
/* gdbarch_addr_bits_remove is wrong if we are being called for a
|
||
non-address (e.g. argument to "signal", "info break", etc.), or
|
||
for pointers to char, in which the low bits *are* significant. */
|
||
return gdbarch_addr_bits_remove (gdbarch, value_as_long (val));
|
||
#else
|
||
|
||
/* There are several targets (IA-64, PowerPC, and others) which
|
||
don't represent pointers to functions as simply the address of
|
||
the function's entry point. For example, on the IA-64, a
|
||
function pointer points to a two-word descriptor, generated by
|
||
the linker, which contains the function's entry point, and the
|
||
value the IA-64 "global pointer" register should have --- to
|
||
support position-independent code. The linker generates
|
||
descriptors only for those functions whose addresses are taken.
|
||
|
||
On such targets, it's difficult for GDB to convert an arbitrary
|
||
function address into a function pointer; it has to either find
|
||
an existing descriptor for that function, or call malloc and
|
||
build its own. On some targets, it is impossible for GDB to
|
||
build a descriptor at all: the descriptor must contain a jump
|
||
instruction; data memory cannot be executed; and code memory
|
||
cannot be modified.
|
||
|
||
Upon entry to this function, if VAL is a value of type `function'
|
||
(that is, TYPE_CODE (VALUE_TYPE (val)) == TYPE_CODE_FUNC), then
|
||
value_address (val) is the address of the function. This is what
|
||
you'll get if you evaluate an expression like `main'. The call
|
||
to COERCE_ARRAY below actually does all the usual unary
|
||
conversions, which includes converting values of type `function'
|
||
to `pointer to function'. This is the challenging conversion
|
||
discussed above. Then, `unpack_long' will convert that pointer
|
||
back into an address.
|
||
|
||
So, suppose the user types `disassemble foo' on an architecture
|
||
with a strange function pointer representation, on which GDB
|
||
cannot build its own descriptors, and suppose further that `foo'
|
||
has no linker-built descriptor. The address->pointer conversion
|
||
will signal an error and prevent the command from running, even
|
||
though the next step would have been to convert the pointer
|
||
directly back into the same address.
|
||
|
||
The following shortcut avoids this whole mess. If VAL is a
|
||
function, just return its address directly. */
|
||
if (TYPE_CODE (value_type (val)) == TYPE_CODE_FUNC
|
||
|| TYPE_CODE (value_type (val)) == TYPE_CODE_METHOD)
|
||
return value_address (val);
|
||
|
||
val = coerce_array (val);
|
||
|
||
/* Some architectures (e.g. Harvard), map instruction and data
|
||
addresses onto a single large unified address space. For
|
||
instance: An architecture may consider a large integer in the
|
||
range 0x10000000 .. 0x1000ffff to already represent a data
|
||
addresses (hence not need a pointer to address conversion) while
|
||
a small integer would still need to be converted integer to
|
||
pointer to address. Just assume such architectures handle all
|
||
integer conversions in a single function. */
|
||
|
||
/* JimB writes:
|
||
|
||
I think INTEGER_TO_ADDRESS is a good idea as proposed --- but we
|
||
must admonish GDB hackers to make sure its behavior matches the
|
||
compiler's, whenever possible.
|
||
|
||
In general, I think GDB should evaluate expressions the same way
|
||
the compiler does. When the user copies an expression out of
|
||
their source code and hands it to a `print' command, they should
|
||
get the same value the compiler would have computed. Any
|
||
deviation from this rule can cause major confusion and annoyance,
|
||
and needs to be justified carefully. In other words, GDB doesn't
|
||
really have the freedom to do these conversions in clever and
|
||
useful ways.
|
||
|
||
AndrewC pointed out that users aren't complaining about how GDB
|
||
casts integers to pointers; they are complaining that they can't
|
||
take an address from a disassembly listing and give it to `x/i'.
|
||
This is certainly important.
|
||
|
||
Adding an architecture method like integer_to_address() certainly
|
||
makes it possible for GDB to "get it right" in all circumstances
|
||
--- the target has complete control over how things get done, so
|
||
people can Do The Right Thing for their target without breaking
|
||
anyone else. The standard doesn't specify how integers get
|
||
converted to pointers; usually, the ABI doesn't either, but
|
||
ABI-specific code is a more reasonable place to handle it. */
|
||
|
||
if (TYPE_CODE (value_type (val)) != TYPE_CODE_PTR
|
||
&& TYPE_CODE (value_type (val)) != TYPE_CODE_REF
|
||
&& gdbarch_integer_to_address_p (gdbarch))
|
||
return gdbarch_integer_to_address (gdbarch, value_type (val),
|
||
value_contents (val));
|
||
|
||
return unpack_long (value_type (val), value_contents (val));
|
||
#endif
|
||
}
|
||
|
||
/* Unpack raw data (copied from debugee, target byte order) at VALADDR
|
||
as a long, or as a double, assuming the raw data is described
|
||
by type TYPE. Knows how to convert different sizes of values
|
||
and can convert between fixed and floating point. We don't assume
|
||
any alignment for the raw data. Return value is in host byte order.
|
||
|
||
If you want functions and arrays to be coerced to pointers, and
|
||
references to be dereferenced, call value_as_long() instead.
|
||
|
||
C++: It is assumed that the front-end has taken care of
|
||
all matters concerning pointers to members. A pointer
|
||
to member which reaches here is considered to be equivalent
|
||
to an INT (or some size). After all, it is only an offset. */
|
||
|
||
LONGEST
|
||
unpack_long (struct type *type, const gdb_byte *valaddr)
|
||
{
|
||
enum bfd_endian byte_order = gdbarch_byte_order (get_type_arch (type));
|
||
enum type_code code = TYPE_CODE (type);
|
||
int len = TYPE_LENGTH (type);
|
||
int nosign = TYPE_UNSIGNED (type);
|
||
|
||
switch (code)
|
||
{
|
||
case TYPE_CODE_TYPEDEF:
|
||
return unpack_long (check_typedef (type), valaddr);
|
||
case TYPE_CODE_ENUM:
|
||
case TYPE_CODE_FLAGS:
|
||
case TYPE_CODE_BOOL:
|
||
case TYPE_CODE_INT:
|
||
case TYPE_CODE_CHAR:
|
||
case TYPE_CODE_RANGE:
|
||
case TYPE_CODE_MEMBERPTR:
|
||
if (nosign)
|
||
return extract_unsigned_integer (valaddr, len, byte_order);
|
||
else
|
||
return extract_signed_integer (valaddr, len, byte_order);
|
||
|
||
case TYPE_CODE_FLT:
|
||
return extract_typed_floating (valaddr, type);
|
||
|
||
case TYPE_CODE_DECFLOAT:
|
||
/* libdecnumber has a function to convert from decimal to integer, but
|
||
it doesn't work when the decimal number has a fractional part. */
|
||
return decimal_to_doublest (valaddr, len, byte_order);
|
||
|
||
case TYPE_CODE_PTR:
|
||
case TYPE_CODE_REF:
|
||
/* Assume a CORE_ADDR can fit in a LONGEST (for now). Not sure
|
||
whether we want this to be true eventually. */
|
||
return extract_typed_address (valaddr, type);
|
||
|
||
default:
|
||
error (_("Value can't be converted to integer."));
|
||
}
|
||
return 0; /* Placate lint. */
|
||
}
|
||
|
||
/* Return a double value from the specified type and address.
|
||
INVP points to an int which is set to 0 for valid value,
|
||
1 for invalid value (bad float format). In either case,
|
||
the returned double is OK to use. Argument is in target
|
||
format, result is in host format. */
|
||
|
||
DOUBLEST
|
||
unpack_double (struct type *type, const gdb_byte *valaddr, int *invp)
|
||
{
|
||
enum bfd_endian byte_order = gdbarch_byte_order (get_type_arch (type));
|
||
enum type_code code;
|
||
int len;
|
||
int nosign;
|
||
|
||
*invp = 0; /* Assume valid. */
|
||
CHECK_TYPEDEF (type);
|
||
code = TYPE_CODE (type);
|
||
len = TYPE_LENGTH (type);
|
||
nosign = TYPE_UNSIGNED (type);
|
||
if (code == TYPE_CODE_FLT)
|
||
{
|
||
/* NOTE: cagney/2002-02-19: There was a test here to see if the
|
||
floating-point value was valid (using the macro
|
||
INVALID_FLOAT). That test/macro have been removed.
|
||
|
||
It turns out that only the VAX defined this macro and then
|
||
only in a non-portable way. Fixing the portability problem
|
||
wouldn't help since the VAX floating-point code is also badly
|
||
bit-rotten. The target needs to add definitions for the
|
||
methods gdbarch_float_format and gdbarch_double_format - these
|
||
exactly describe the target floating-point format. The
|
||
problem here is that the corresponding floatformat_vax_f and
|
||
floatformat_vax_d values these methods should be set to are
|
||
also not defined either. Oops!
|
||
|
||
Hopefully someone will add both the missing floatformat
|
||
definitions and the new cases for floatformat_is_valid (). */
|
||
|
||
if (!floatformat_is_valid (floatformat_from_type (type), valaddr))
|
||
{
|
||
*invp = 1;
|
||
return 0.0;
|
||
}
|
||
|
||
return extract_typed_floating (valaddr, type);
|
||
}
|
||
else if (code == TYPE_CODE_DECFLOAT)
|
||
return decimal_to_doublest (valaddr, len, byte_order);
|
||
else if (nosign)
|
||
{
|
||
/* Unsigned -- be sure we compensate for signed LONGEST. */
|
||
return (ULONGEST) unpack_long (type, valaddr);
|
||
}
|
||
else
|
||
{
|
||
/* Signed -- we are OK with unpack_long. */
|
||
return unpack_long (type, valaddr);
|
||
}
|
||
}
|
||
|
||
/* Unpack raw data (copied from debugee, target byte order) at VALADDR
|
||
as a CORE_ADDR, assuming the raw data is described by type TYPE.
|
||
We don't assume any alignment for the raw data. Return value is in
|
||
host byte order.
|
||
|
||
If you want functions and arrays to be coerced to pointers, and
|
||
references to be dereferenced, call value_as_address() instead.
|
||
|
||
C++: It is assumed that the front-end has taken care of
|
||
all matters concerning pointers to members. A pointer
|
||
to member which reaches here is considered to be equivalent
|
||
to an INT (or some size). After all, it is only an offset. */
|
||
|
||
CORE_ADDR
|
||
unpack_pointer (struct type *type, const gdb_byte *valaddr)
|
||
{
|
||
/* Assume a CORE_ADDR can fit in a LONGEST (for now). Not sure
|
||
whether we want this to be true eventually. */
|
||
return unpack_long (type, valaddr);
|
||
}
|
||
|
||
|
||
/* Get the value of the FIELDN'th field (which must be static) of
|
||
TYPE. Return NULL if the field doesn't exist or has been
|
||
optimized out. */
|
||
|
||
struct value *
|
||
value_static_field (struct type *type, int fieldno)
|
||
{
|
||
struct value *retval;
|
||
|
||
if (TYPE_FIELD_LOC_KIND (type, fieldno) == FIELD_LOC_KIND_PHYSADDR)
|
||
{
|
||
retval = value_at (TYPE_FIELD_TYPE (type, fieldno),
|
||
TYPE_FIELD_STATIC_PHYSADDR (type, fieldno));
|
||
}
|
||
else
|
||
{
|
||
char *phys_name = TYPE_FIELD_STATIC_PHYSNAME (type, fieldno);
|
||
struct symbol *sym = lookup_symbol (phys_name, 0, VAR_DOMAIN, 0);
|
||
if (sym == NULL)
|
||
{
|
||
/* With some compilers, e.g. HP aCC, static data members are reported
|
||
as non-debuggable symbols */
|
||
struct minimal_symbol *msym = lookup_minimal_symbol (phys_name, NULL, NULL);
|
||
if (!msym)
|
||
return NULL;
|
||
else
|
||
{
|
||
retval = value_at (TYPE_FIELD_TYPE (type, fieldno),
|
||
SYMBOL_VALUE_ADDRESS (msym));
|
||
}
|
||
}
|
||
else
|
||
{
|
||
/* SYM should never have a SYMBOL_CLASS which will require
|
||
read_var_value to use the FRAME parameter. */
|
||
if (symbol_read_needs_frame (sym))
|
||
warning (_("static field's value depends on the current "
|
||
"frame - bad debug info?"));
|
||
retval = read_var_value (sym, NULL);
|
||
}
|
||
if (retval && VALUE_LVAL (retval) == lval_memory)
|
||
SET_FIELD_PHYSADDR (TYPE_FIELD (type, fieldno),
|
||
value_address (retval));
|
||
}
|
||
return retval;
|
||
}
|
||
|
||
/* Change the enclosing type of a value object VAL to NEW_ENCL_TYPE.
|
||
You have to be careful here, since the size of the data area for the value
|
||
is set by the length of the enclosing type. So if NEW_ENCL_TYPE is bigger
|
||
than the old enclosing type, you have to allocate more space for the data.
|
||
The return value is a pointer to the new version of this value structure. */
|
||
|
||
struct value *
|
||
value_change_enclosing_type (struct value *val, struct type *new_encl_type)
|
||
{
|
||
if (TYPE_LENGTH (new_encl_type) > TYPE_LENGTH (value_enclosing_type (val)))
|
||
val->contents =
|
||
(gdb_byte *) xrealloc (val->contents, TYPE_LENGTH (new_encl_type));
|
||
|
||
val->enclosing_type = new_encl_type;
|
||
return val;
|
||
}
|
||
|
||
/* Given a value ARG1 (offset by OFFSET bytes)
|
||
of a struct or union type ARG_TYPE,
|
||
extract and return the value of one of its (non-static) fields.
|
||
FIELDNO says which field. */
|
||
|
||
struct value *
|
||
value_primitive_field (struct value *arg1, int offset,
|
||
int fieldno, struct type *arg_type)
|
||
{
|
||
struct value *v;
|
||
struct type *type;
|
||
|
||
CHECK_TYPEDEF (arg_type);
|
||
type = TYPE_FIELD_TYPE (arg_type, fieldno);
|
||
type = check_typedef (type);
|
||
|
||
/* Handle packed fields */
|
||
|
||
if (TYPE_FIELD_BITSIZE (arg_type, fieldno))
|
||
{
|
||
/* Create a new value for the bitfield, with bitpos and bitsize
|
||
set. If possible, arrange offset and bitpos so that we can
|
||
do a single aligned read of the size of the containing type.
|
||
Otherwise, adjust offset to the byte containing the first
|
||
bit. Assume that the address, offset, and embedded offset
|
||
are sufficiently aligned. */
|
||
int bitpos = TYPE_FIELD_BITPOS (arg_type, fieldno);
|
||
int container_bitsize = TYPE_LENGTH (type) * 8;
|
||
|
||
v = allocate_value_lazy (type);
|
||
v->bitsize = TYPE_FIELD_BITSIZE (arg_type, fieldno);
|
||
if ((bitpos % container_bitsize) + v->bitsize <= container_bitsize
|
||
&& TYPE_LENGTH (type) <= (int) sizeof (LONGEST))
|
||
v->bitpos = bitpos % container_bitsize;
|
||
else
|
||
v->bitpos = bitpos % 8;
|
||
v->offset = value_embedded_offset (arg1)
|
||
+ (bitpos - v->bitpos) / 8;
|
||
v->parent = arg1;
|
||
value_incref (v->parent);
|
||
if (!value_lazy (arg1))
|
||
value_fetch_lazy (v);
|
||
}
|
||
else if (fieldno < TYPE_N_BASECLASSES (arg_type))
|
||
{
|
||
/* This field is actually a base subobject, so preserve the
|
||
entire object's contents for later references to virtual
|
||
bases, etc. */
|
||
|
||
/* Lazy register values with offsets are not supported. */
|
||
if (VALUE_LVAL (arg1) == lval_register && value_lazy (arg1))
|
||
value_fetch_lazy (arg1);
|
||
|
||
if (value_lazy (arg1))
|
||
v = allocate_value_lazy (value_enclosing_type (arg1));
|
||
else
|
||
{
|
||
v = allocate_value (value_enclosing_type (arg1));
|
||
memcpy (value_contents_all_raw (v), value_contents_all_raw (arg1),
|
||
TYPE_LENGTH (value_enclosing_type (arg1)));
|
||
}
|
||
v->type = type;
|
||
v->offset = value_offset (arg1);
|
||
v->embedded_offset = (offset + value_embedded_offset (arg1)
|
||
+ TYPE_FIELD_BITPOS (arg_type, fieldno) / 8);
|
||
}
|
||
else
|
||
{
|
||
/* Plain old data member */
|
||
offset += TYPE_FIELD_BITPOS (arg_type, fieldno) / 8;
|
||
|
||
/* Lazy register values with offsets are not supported. */
|
||
if (VALUE_LVAL (arg1) == lval_register && value_lazy (arg1))
|
||
value_fetch_lazy (arg1);
|
||
|
||
if (value_lazy (arg1))
|
||
v = allocate_value_lazy (type);
|
||
else
|
||
{
|
||
v = allocate_value (type);
|
||
memcpy (value_contents_raw (v),
|
||
value_contents_raw (arg1) + offset,
|
||
TYPE_LENGTH (type));
|
||
}
|
||
v->offset = (value_offset (arg1) + offset
|
||
+ value_embedded_offset (arg1));
|
||
}
|
||
set_value_component_location (v, arg1);
|
||
VALUE_REGNUM (v) = VALUE_REGNUM (arg1);
|
||
VALUE_FRAME_ID (v) = VALUE_FRAME_ID (arg1);
|
||
return v;
|
||
}
|
||
|
||
/* Given a value ARG1 of a struct or union type,
|
||
extract and return the value of one of its (non-static) fields.
|
||
FIELDNO says which field. */
|
||
|
||
struct value *
|
||
value_field (struct value *arg1, int fieldno)
|
||
{
|
||
return value_primitive_field (arg1, 0, fieldno, value_type (arg1));
|
||
}
|
||
|
||
/* Return a non-virtual function as a value.
|
||
F is the list of member functions which contains the desired method.
|
||
J is an index into F which provides the desired method.
|
||
|
||
We only use the symbol for its address, so be happy with either a
|
||
full symbol or a minimal symbol.
|
||
*/
|
||
|
||
struct value *
|
||
value_fn_field (struct value **arg1p, struct fn_field *f, int j, struct type *type,
|
||
int offset)
|
||
{
|
||
struct value *v;
|
||
struct type *ftype = TYPE_FN_FIELD_TYPE (f, j);
|
||
char *physname = TYPE_FN_FIELD_PHYSNAME (f, j);
|
||
struct symbol *sym;
|
||
struct minimal_symbol *msym;
|
||
|
||
sym = lookup_symbol (physname, 0, VAR_DOMAIN, 0);
|
||
if (sym != NULL)
|
||
{
|
||
msym = NULL;
|
||
}
|
||
else
|
||
{
|
||
gdb_assert (sym == NULL);
|
||
msym = lookup_minimal_symbol (physname, NULL, NULL);
|
||
if (msym == NULL)
|
||
return NULL;
|
||
}
|
||
|
||
v = allocate_value (ftype);
|
||
if (sym)
|
||
{
|
||
set_value_address (v, BLOCK_START (SYMBOL_BLOCK_VALUE (sym)));
|
||
}
|
||
else
|
||
{
|
||
/* The minimal symbol might point to a function descriptor;
|
||
resolve it to the actual code address instead. */
|
||
struct objfile *objfile = msymbol_objfile (msym);
|
||
struct gdbarch *gdbarch = get_objfile_arch (objfile);
|
||
|
||
set_value_address (v,
|
||
gdbarch_convert_from_func_ptr_addr
|
||
(gdbarch, SYMBOL_VALUE_ADDRESS (msym), ¤t_target));
|
||
}
|
||
|
||
if (arg1p)
|
||
{
|
||
if (type != value_type (*arg1p))
|
||
*arg1p = value_ind (value_cast (lookup_pointer_type (type),
|
||
value_addr (*arg1p)));
|
||
|
||
/* Move the `this' pointer according to the offset.
|
||
VALUE_OFFSET (*arg1p) += offset;
|
||
*/
|
||
}
|
||
|
||
return v;
|
||
}
|
||
|
||
|
||
/* Unpack a bitfield of the specified FIELD_TYPE, from the anonymous
|
||
object at VALADDR. The bitfield starts at BITPOS bits and contains
|
||
BITSIZE bits.
|
||
|
||
Extracting bits depends on endianness of the machine. Compute the
|
||
number of least significant bits to discard. For big endian machines,
|
||
we compute the total number of bits in the anonymous object, subtract
|
||
off the bit count from the MSB of the object to the MSB of the
|
||
bitfield, then the size of the bitfield, which leaves the LSB discard
|
||
count. For little endian machines, the discard count is simply the
|
||
number of bits from the LSB of the anonymous object to the LSB of the
|
||
bitfield.
|
||
|
||
If the field is signed, we also do sign extension. */
|
||
|
||
LONGEST
|
||
unpack_bits_as_long (struct type *field_type, const gdb_byte *valaddr,
|
||
int bitpos, int bitsize)
|
||
{
|
||
enum bfd_endian byte_order = gdbarch_byte_order (get_type_arch (field_type));
|
||
ULONGEST val;
|
||
ULONGEST valmask;
|
||
int lsbcount;
|
||
int bytes_read;
|
||
|
||
/* Read the minimum number of bytes required; there may not be
|
||
enough bytes to read an entire ULONGEST. */
|
||
CHECK_TYPEDEF (field_type);
|
||
if (bitsize)
|
||
bytes_read = ((bitpos % 8) + bitsize + 7) / 8;
|
||
else
|
||
bytes_read = TYPE_LENGTH (field_type);
|
||
|
||
val = extract_unsigned_integer (valaddr + bitpos / 8,
|
||
bytes_read, byte_order);
|
||
|
||
/* Extract bits. See comment above. */
|
||
|
||
if (gdbarch_bits_big_endian (get_type_arch (field_type)))
|
||
lsbcount = (bytes_read * 8 - bitpos % 8 - bitsize);
|
||
else
|
||
lsbcount = (bitpos % 8);
|
||
val >>= lsbcount;
|
||
|
||
/* If the field does not entirely fill a LONGEST, then zero the sign bits.
|
||
If the field is signed, and is negative, then sign extend. */
|
||
|
||
if ((bitsize > 0) && (bitsize < 8 * (int) sizeof (val)))
|
||
{
|
||
valmask = (((ULONGEST) 1) << bitsize) - 1;
|
||
val &= valmask;
|
||
if (!TYPE_UNSIGNED (field_type))
|
||
{
|
||
if (val & (valmask ^ (valmask >> 1)))
|
||
{
|
||
val |= ~valmask;
|
||
}
|
||
}
|
||
}
|
||
return (val);
|
||
}
|
||
|
||
/* Unpack a field FIELDNO of the specified TYPE, from the anonymous object at
|
||
VALADDR. See unpack_bits_as_long for more details. */
|
||
|
||
LONGEST
|
||
unpack_field_as_long (struct type *type, const gdb_byte *valaddr, int fieldno)
|
||
{
|
||
int bitpos = TYPE_FIELD_BITPOS (type, fieldno);
|
||
int bitsize = TYPE_FIELD_BITSIZE (type, fieldno);
|
||
struct type *field_type = TYPE_FIELD_TYPE (type, fieldno);
|
||
|
||
return unpack_bits_as_long (field_type, valaddr, bitpos, bitsize);
|
||
}
|
||
|
||
/* Modify the value of a bitfield. ADDR points to a block of memory in
|
||
target byte order; the bitfield starts in the byte pointed to. FIELDVAL
|
||
is the desired value of the field, in host byte order. BITPOS and BITSIZE
|
||
indicate which bits (in target bit order) comprise the bitfield.
|
||
Requires 0 < BITSIZE <= lbits, 0 <= BITPOS+BITSIZE <= lbits, and
|
||
0 <= BITPOS, where lbits is the size of a LONGEST in bits. */
|
||
|
||
void
|
||
modify_field (struct type *type, gdb_byte *addr,
|
||
LONGEST fieldval, int bitpos, int bitsize)
|
||
{
|
||
enum bfd_endian byte_order = gdbarch_byte_order (get_type_arch (type));
|
||
ULONGEST oword;
|
||
ULONGEST mask = (ULONGEST) -1 >> (8 * sizeof (ULONGEST) - bitsize);
|
||
|
||
/* If a negative fieldval fits in the field in question, chop
|
||
off the sign extension bits. */
|
||
if ((~fieldval & ~(mask >> 1)) == 0)
|
||
fieldval &= mask;
|
||
|
||
/* Warn if value is too big to fit in the field in question. */
|
||
if (0 != (fieldval & ~mask))
|
||
{
|
||
/* FIXME: would like to include fieldval in the message, but
|
||
we don't have a sprintf_longest. */
|
||
warning (_("Value does not fit in %d bits."), bitsize);
|
||
|
||
/* Truncate it, otherwise adjoining fields may be corrupted. */
|
||
fieldval &= mask;
|
||
}
|
||
|
||
oword = extract_unsigned_integer (addr, sizeof oword, byte_order);
|
||
|
||
/* Shifting for bit field depends on endianness of the target machine. */
|
||
if (gdbarch_bits_big_endian (get_type_arch (type)))
|
||
bitpos = sizeof (oword) * 8 - bitpos - bitsize;
|
||
|
||
oword &= ~(mask << bitpos);
|
||
oword |= fieldval << bitpos;
|
||
|
||
store_unsigned_integer (addr, sizeof oword, byte_order, oword);
|
||
}
|
||
|
||
/* Pack NUM into BUF using a target format of TYPE. */
|
||
|
||
void
|
||
pack_long (gdb_byte *buf, struct type *type, LONGEST num)
|
||
{
|
||
enum bfd_endian byte_order = gdbarch_byte_order (get_type_arch (type));
|
||
int len;
|
||
|
||
type = check_typedef (type);
|
||
len = TYPE_LENGTH (type);
|
||
|
||
switch (TYPE_CODE (type))
|
||
{
|
||
case TYPE_CODE_INT:
|
||
case TYPE_CODE_CHAR:
|
||
case TYPE_CODE_ENUM:
|
||
case TYPE_CODE_FLAGS:
|
||
case TYPE_CODE_BOOL:
|
||
case TYPE_CODE_RANGE:
|
||
case TYPE_CODE_MEMBERPTR:
|
||
store_signed_integer (buf, len, byte_order, num);
|
||
break;
|
||
|
||
case TYPE_CODE_REF:
|
||
case TYPE_CODE_PTR:
|
||
store_typed_address (buf, type, (CORE_ADDR) num);
|
||
break;
|
||
|
||
default:
|
||
error (_("Unexpected type (%d) encountered for integer constant."),
|
||
TYPE_CODE (type));
|
||
}
|
||
}
|
||
|
||
|
||
/* Convert C numbers into newly allocated values. */
|
||
|
||
struct value *
|
||
value_from_longest (struct type *type, LONGEST num)
|
||
{
|
||
struct value *val = allocate_value (type);
|
||
|
||
pack_long (value_contents_raw (val), type, num);
|
||
|
||
return val;
|
||
}
|
||
|
||
|
||
/* Create a value representing a pointer of type TYPE to the address
|
||
ADDR. */
|
||
struct value *
|
||
value_from_pointer (struct type *type, CORE_ADDR addr)
|
||
{
|
||
struct value *val = allocate_value (type);
|
||
store_typed_address (value_contents_raw (val), check_typedef (type), addr);
|
||
return val;
|
||
}
|
||
|
||
|
||
/* Create a value of type TYPE whose contents come from VALADDR, if it
|
||
is non-null, and whose memory address (in the inferior) is
|
||
ADDRESS. */
|
||
|
||
struct value *
|
||
value_from_contents_and_address (struct type *type,
|
||
const gdb_byte *valaddr,
|
||
CORE_ADDR address)
|
||
{
|
||
struct value *v = allocate_value (type);
|
||
if (valaddr == NULL)
|
||
set_value_lazy (v, 1);
|
||
else
|
||
memcpy (value_contents_raw (v), valaddr, TYPE_LENGTH (type));
|
||
set_value_address (v, address);
|
||
VALUE_LVAL (v) = lval_memory;
|
||
return v;
|
||
}
|
||
|
||
struct value *
|
||
value_from_double (struct type *type, DOUBLEST num)
|
||
{
|
||
struct value *val = allocate_value (type);
|
||
struct type *base_type = check_typedef (type);
|
||
enum type_code code = TYPE_CODE (base_type);
|
||
int len = TYPE_LENGTH (base_type);
|
||
|
||
if (code == TYPE_CODE_FLT)
|
||
{
|
||
store_typed_floating (value_contents_raw (val), base_type, num);
|
||
}
|
||
else
|
||
error (_("Unexpected type encountered for floating constant."));
|
||
|
||
return val;
|
||
}
|
||
|
||
struct value *
|
||
value_from_decfloat (struct type *type, const gdb_byte *dec)
|
||
{
|
||
struct value *val = allocate_value (type);
|
||
|
||
memcpy (value_contents_raw (val), dec, TYPE_LENGTH (type));
|
||
|
||
return val;
|
||
}
|
||
|
||
struct value *
|
||
coerce_ref (struct value *arg)
|
||
{
|
||
struct type *value_type_arg_tmp = check_typedef (value_type (arg));
|
||
if (TYPE_CODE (value_type_arg_tmp) == TYPE_CODE_REF)
|
||
arg = value_at_lazy (TYPE_TARGET_TYPE (value_type_arg_tmp),
|
||
unpack_pointer (value_type (arg),
|
||
value_contents (arg)));
|
||
return arg;
|
||
}
|
||
|
||
struct value *
|
||
coerce_array (struct value *arg)
|
||
{
|
||
struct type *type;
|
||
|
||
arg = coerce_ref (arg);
|
||
type = check_typedef (value_type (arg));
|
||
|
||
switch (TYPE_CODE (type))
|
||
{
|
||
case TYPE_CODE_ARRAY:
|
||
if (current_language->c_style_arrays)
|
||
arg = value_coerce_array (arg);
|
||
break;
|
||
case TYPE_CODE_FUNC:
|
||
arg = value_coerce_function (arg);
|
||
break;
|
||
}
|
||
return arg;
|
||
}
|
||
|
||
|
||
/* Return true if the function returning the specified type is using
|
||
the convention of returning structures in memory (passing in the
|
||
address as a hidden first parameter). */
|
||
|
||
int
|
||
using_struct_return (struct gdbarch *gdbarch,
|
||
struct type *func_type, struct type *value_type)
|
||
{
|
||
enum type_code code = TYPE_CODE (value_type);
|
||
|
||
if (code == TYPE_CODE_ERROR)
|
||
error (_("Function return type unknown."));
|
||
|
||
if (code == TYPE_CODE_VOID)
|
||
/* A void return value is never in memory. See also corresponding
|
||
code in "print_return_value". */
|
||
return 0;
|
||
|
||
/* Probe the architecture for the return-value convention. */
|
||
return (gdbarch_return_value (gdbarch, func_type, value_type,
|
||
NULL, NULL, NULL)
|
||
!= RETURN_VALUE_REGISTER_CONVENTION);
|
||
}
|
||
|
||
/* Set the initialized field in a value struct. */
|
||
|
||
void
|
||
set_value_initialized (struct value *val, int status)
|
||
{
|
||
val->initialized = status;
|
||
}
|
||
|
||
/* Return the initialized field in a value struct. */
|
||
|
||
int
|
||
value_initialized (struct value *val)
|
||
{
|
||
return val->initialized;
|
||
}
|
||
|
||
void
|
||
_initialize_values (void)
|
||
{
|
||
add_cmd ("convenience", no_class, show_convenience, _("\
|
||
Debugger convenience (\"$foo\") variables.\n\
|
||
These variables are created when you assign them values;\n\
|
||
thus, \"print $foo=1\" gives \"$foo\" the value 1. Values may be any type.\n\
|
||
\n\
|
||
A few convenience variables are given values automatically:\n\
|
||
\"$_\"holds the last address examined with \"x\" or \"info lines\",\n\
|
||
\"$__\" holds the contents of the last address examined with \"x\"."),
|
||
&showlist);
|
||
|
||
add_cmd ("values", no_class, show_values,
|
||
_("Elements of value history around item number IDX (or last ten)."),
|
||
&showlist);
|
||
|
||
add_com ("init-if-undefined", class_vars, init_if_undefined_command, _("\
|
||
Initialize a convenience variable if necessary.\n\
|
||
init-if-undefined VARIABLE = EXPRESSION\n\
|
||
Set an internal VARIABLE to the result of the EXPRESSION if it does not\n\
|
||
exist or does not contain a value. The EXPRESSION is not evaluated if the\n\
|
||
VARIABLE is already initialized."));
|
||
|
||
add_prefix_cmd ("function", no_class, function_command, _("\
|
||
Placeholder command for showing help on convenience functions."),
|
||
&functionlist, "function ", 0, &cmdlist);
|
||
}
|