1746 lines
51 KiB
C
1746 lines
51 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
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Free Software Foundation, Inc.
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||
|
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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 2 of the License, or
|
||
(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
|
||
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, write to the Free Software
|
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Foundation, Inc., 51 Franklin Street, Fifth Floor,
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Boston, MA 02110-1301, USA. */
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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 "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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/* Prototypes for exported functions. */
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void _initialize_values (void);
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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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} 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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BITS_BIG_ENDIAN=0 targets, it is the position of the LSB. For
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BITS_BIG_ENDIAN=1 targets, it is the position of the MSB. */
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int bitpos;
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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 or put into the value history are taken off this
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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 memory at address in the
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location.address field plus the offset field (and the lval field
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should be lval_memory).
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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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/* Actual contents of the value. For use of this value; setting it
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uses the stuff above. Not valid if lazy is nonzero. Target
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byte-order. We force it to be aligned properly for any possible
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value. Note that a value therefore extends beyond what is
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declared here. */
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union
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{
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gdb_byte contents[1];
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DOUBLEST force_doublest_align;
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LONGEST force_longest_align;
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CORE_ADDR force_core_addr_align;
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void *force_pointer_align;
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} aligner;
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/* Do not add any new members here -- contents above will trash
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them. */
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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 value that has the correct length 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;
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struct type *atype = check_typedef (type);
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val = (struct value *) xzalloc (sizeof (struct value) + TYPE_LENGTH (atype));
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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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VALUE_ADDRESS (val) = 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 = 0;
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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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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 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 *range_type
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= create_range_type ((struct type *) NULL, builtin_type_int,
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low_bound, count + low_bound - 1);
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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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return allocate_value (create_array_type ((struct type *) NULL,
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type, range_type));
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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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gdb_byte *
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value_contents_raw (struct value *value)
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{
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return value->aligner.contents + value->embedded_offset;
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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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return value->aligner.contents;
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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->aligner.contents;
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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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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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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);
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}
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gdb_byte *
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value_contents_writeable (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_raw (value);
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}
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/* Return non-zero if VAL1 and VAL2 have the same contents. Note that
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this function is different from value_equal; in C the operator ==
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can return 0 even if the two values being compared are equal. */
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int
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value_contents_equal (struct value *val1, struct value *val2)
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{
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struct type *type1;
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struct type *type2;
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int len;
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type1 = check_typedef (value_type (val1));
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type2 = check_typedef (value_type (val2));
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len = TYPE_LENGTH (type1);
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if (len != TYPE_LENGTH (type2))
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return 0;
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return (memcmp (value_contents (val1), value_contents (val2), len) == 0);
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}
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int
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value_optimized_out (struct value *value)
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{
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return value->optimized_out;
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}
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void
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set_value_optimized_out (struct value *value, int val)
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{
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value->optimized_out = val;
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}
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int
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value_embedded_offset (struct value *value)
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{
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return value->embedded_offset;
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||
}
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void
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set_value_embedded_offset (struct value *value, int val)
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{
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||
value->embedded_offset = val;
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||
}
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||
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int
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||
value_pointed_to_offset (struct value *value)
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||
{
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return value->pointed_to_offset;
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}
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void
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set_value_pointed_to_offset (struct value *value, int val)
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{
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value->pointed_to_offset = val;
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}
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||
enum lval_type *
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deprecated_value_lval_hack (struct value *value)
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||
{
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||
return &value->lval;
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||
}
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||
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CORE_ADDR *
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||
deprecated_value_address_hack (struct value *value)
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||
{
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||
return &value->location.address;
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||
}
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||
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||
struct internalvar **
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||
deprecated_value_internalvar_hack (struct value *value)
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||
{
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||
return &value->location.internalvar;
|
||
}
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||
|
||
struct frame_id *
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||
deprecated_value_frame_id_hack (struct value *value)
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||
{
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||
return &value->frame_id;
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||
}
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||
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||
short *
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||
deprecated_value_regnum_hack (struct value *value)
|
||
{
|
||
return &value->regnum;
|
||
}
|
||
|
||
int
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||
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;
|
||
}
|
||
|
||
/* 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).
|
||
Called after each command, successful or not. */
|
||
|
||
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 = 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)));
|
||
|
||
}
|
||
return val;
|
||
}
|
||
|
||
/* 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 $%d."), absnum);
|
||
|
||
absnum--;
|
||
|
||
/* Now absnum is always absolute and origin zero. */
|
||
|
||
chunk = value_history_chain;
|
||
for (i = (value_history_count - 1) / VALUE_HISTORY_CHUNK - absnum / VALUE_HISTORY_CHUNK;
|
||
i > 0; i--)
|
||
chunk = chunk->next;
|
||
|
||
return value_copy (chunk->values[absnum % VALUE_HISTORY_CHUNK]);
|
||
}
|
||
|
||
static void
|
||
show_values (char *num_exp, int from_tty)
|
||
{
|
||
int i;
|
||
struct value *val;
|
||
static int num = 1;
|
||
|
||
if (num_exp)
|
||
{
|
||
/* "info history +" should print from the stored position.
|
||
"info history <exp>" should print around value number <exp>. */
|
||
if (num_exp[0] != '+' || num_exp[1] != '\0')
|
||
num = parse_and_eval_long (num_exp) - 5;
|
||
}
|
||
else
|
||
{
|
||
/* "info history" means print the last 10 values. */
|
||
num = value_history_count - 9;
|
||
}
|
||
|
||
if (num <= 0)
|
||
num = 1;
|
||
|
||
for (i = num; i < num + 10 && i <= value_history_count; i++)
|
||
{
|
||
val = access_value_history (i);
|
||
printf_filtered (("$%d = "), i);
|
||
value_print (val, gdb_stdout, 0, Val_pretty_default);
|
||
printf_filtered (("\n"));
|
||
}
|
||
|
||
/* The next "info history +" should start after what we just printed. */
|
||
num += 10;
|
||
|
||
/* Hitting just return after this command should do the same thing as
|
||
"info history +". If num_exp is null, this is unnecessary, since
|
||
"info history +" is not useful after "info history". */
|
||
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. */
|
||
|
||
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 (TYPE_CODE (value_type (intvar->value)) == TYPE_CODE_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,
|
||
one is created, with a void value. */
|
||
|
||
struct internalvar *
|
||
lookup_internalvar (char *name)
|
||
{
|
||
struct internalvar *var;
|
||
|
||
for (var = internalvars; var; var = var->next)
|
||
if (strcmp (var->name, name) == 0)
|
||
return var;
|
||
|
||
var = (struct internalvar *) xmalloc (sizeof (struct internalvar));
|
||
var->name = concat (name, (char *)NULL);
|
||
var->value = allocate_value (builtin_type_void);
|
||
var->endian = gdbarch_byte_order (current_gdbarch);
|
||
release_value (var->value);
|
||
var->next = internalvars;
|
||
internalvars = var;
|
||
return var;
|
||
}
|
||
|
||
struct value *
|
||
value_of_internalvar (struct internalvar *var)
|
||
{
|
||
struct value *val;
|
||
int i, j;
|
||
gdb_byte temp;
|
||
|
||
val = value_copy (var->value);
|
||
if (value_lazy (val))
|
||
value_fetch_lazy (val);
|
||
VALUE_LVAL (val) = lval_internalvar;
|
||
VALUE_INTERNALVAR (val) = var;
|
||
|
||
/* Values are always stored in the target's byte order. When connected to a
|
||
target this will most likely always be correct, so there's normally no
|
||
need to worry about it.
|
||
|
||
However, internal variables can be set up before the target endian is
|
||
known and so may become out of date. Fix it up before anybody sees.
|
||
|
||
Internal variables usually hold simple scalar values, and we can
|
||
correct those. More complex values (e.g. structures and floating
|
||
point types) are left alone, because they would be too complicated
|
||
to correct. */
|
||
|
||
if (var->endian != gdbarch_byte_order (current_gdbarch))
|
||
{
|
||
gdb_byte *array = value_contents_raw (val);
|
||
struct type *type = check_typedef (value_enclosing_type (val));
|
||
switch (TYPE_CODE (type))
|
||
{
|
||
case TYPE_CODE_INT:
|
||
case TYPE_CODE_PTR:
|
||
/* Reverse the bytes. */
|
||
for (i = 0, j = TYPE_LENGTH (type) - 1; i < j; i++, j--)
|
||
{
|
||
temp = array[j];
|
||
array[j] = array[i];
|
||
array[i] = temp;
|
||
}
|
||
break;
|
||
}
|
||
}
|
||
|
||
return val;
|
||
}
|
||
|
||
void
|
||
set_internalvar_component (struct internalvar *var, int offset, int bitpos,
|
||
int bitsize, struct value *newval)
|
||
{
|
||
gdb_byte *addr = value_contents_writeable (var->value) + offset;
|
||
|
||
if (bitsize)
|
||
modify_field (addr, value_as_long (newval),
|
||
bitpos, bitsize);
|
||
else
|
||
memcpy (addr, value_contents (newval), TYPE_LENGTH (value_type (newval)));
|
||
}
|
||
|
||
void
|
||
set_internalvar (struct internalvar *var, struct value *val)
|
||
{
|
||
struct value *newval;
|
||
|
||
newval = value_copy (val);
|
||
newval->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 (newval))
|
||
value_fetch_lazy (newval);
|
||
|
||
/* Begin code which must not call error(). If var->value points to
|
||
something free'd, an error() obviously leaves a dangling pointer.
|
||
But we also get a danling pointer if var->value points to
|
||
something in the value chain (i.e., before release_value is
|
||
called), because after the error free_all_values will get called before
|
||
long. */
|
||
xfree (var->value);
|
||
var->value = newval;
|
||
var->endian = gdbarch_byte_order (current_gdbarch);
|
||
release_value (newval);
|
||
/* End code which must not call error(). */
|
||
}
|
||
|
||
char *
|
||
internalvar_name (struct internalvar *var)
|
||
{
|
||
return var->name;
|
||
}
|
||
|
||
/* Update VALUE before discarding OBJFILE. COPIED_TYPES is used to
|
||
prevent cycles / duplicates. */
|
||
|
||
static 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);
|
||
}
|
||
|
||
/* 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;
|
||
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_value (var->value, objfile, copied_types);
|
||
|
||
htab_delete (copied_types);
|
||
}
|
||
|
||
static void
|
||
show_convenience (char *ignore, int from_tty)
|
||
{
|
||
struct internalvar *var;
|
||
int varseen = 0;
|
||
|
||
for (var = internalvars; var; var = var->next)
|
||
{
|
||
if (!varseen)
|
||
{
|
||
varseen = 1;
|
||
}
|
||
printf_filtered (("$%s = "), var->name);
|
||
value_print (value_of_internalvar (var), gdb_stdout,
|
||
0, Val_pretty_default);
|
||
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)
|
||
{
|
||
/* 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 (current_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 (current_gdbarch))
|
||
return gdbarch_integer_to_address (current_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 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);
|
||
else
|
||
return extract_signed_integer (valaddr, len);
|
||
|
||
case TYPE_CODE_FLT:
|
||
return extract_typed_floating (valaddr, type);
|
||
|
||
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 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 (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_STATIC_HAS_ADDR (type, fieldno))
|
||
{
|
||
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, NULL);
|
||
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->enclosing_type = new_encl_type;
|
||
return val;
|
||
}
|
||
else
|
||
{
|
||
struct value *new_val;
|
||
struct value *prev;
|
||
|
||
new_val = (struct value *) xrealloc (val, sizeof (struct value) + TYPE_LENGTH (new_encl_type));
|
||
|
||
new_val->enclosing_type = new_encl_type;
|
||
|
||
/* We have to make sure this ends up in the same place in the value
|
||
chain as the original copy, so it's clean-up behavior is the same.
|
||
If the value has been released, this is a waste of time, but there
|
||
is no way to tell that in advance, so... */
|
||
|
||
if (val != all_values)
|
||
{
|
||
for (prev = all_values; prev != NULL; prev = prev->next)
|
||
{
|
||
if (prev->next == val)
|
||
{
|
||
prev->next = new_val;
|
||
break;
|
||
}
|
||
}
|
||
}
|
||
|
||
return new_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);
|
||
|
||
/* Handle packed fields */
|
||
|
||
if (TYPE_FIELD_BITSIZE (arg_type, fieldno))
|
||
{
|
||
v = value_from_longest (type,
|
||
unpack_field_as_long (arg_type,
|
||
value_contents (arg1)
|
||
+ offset,
|
||
fieldno));
|
||
v->bitpos = TYPE_FIELD_BITPOS (arg_type, fieldno) % 8;
|
||
v->bitsize = TYPE_FIELD_BITSIZE (arg_type, fieldno);
|
||
v->offset = value_offset (arg1) + offset
|
||
+ TYPE_FIELD_BITPOS (arg_type, fieldno) / 8;
|
||
}
|
||
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. */
|
||
v = allocate_value (value_enclosing_type (arg1));
|
||
v->type = type;
|
||
if (value_lazy (arg1))
|
||
set_value_lazy (v, 1);
|
||
else
|
||
memcpy (value_contents_all_raw (v), value_contents_all_raw (arg1),
|
||
TYPE_LENGTH (value_enclosing_type (arg1)));
|
||
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;
|
||
v = allocate_value (type);
|
||
if (value_lazy (arg1))
|
||
set_value_lazy (v, 1);
|
||
else
|
||
memcpy (value_contents_raw (v),
|
||
value_contents_raw (arg1) + offset,
|
||
TYPE_LENGTH (type));
|
||
v->offset = (value_offset (arg1) + offset
|
||
+ value_embedded_offset (arg1));
|
||
}
|
||
VALUE_LVAL (v) = VALUE_LVAL (arg1);
|
||
if (VALUE_LVAL (arg1) == lval_internalvar)
|
||
VALUE_LVAL (v) = lval_internalvar_component;
|
||
v->location = arg1->location;
|
||
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, NULL);
|
||
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)
|
||
{
|
||
VALUE_ADDRESS (v) = BLOCK_START (SYMBOL_BLOCK_VALUE (sym));
|
||
}
|
||
else
|
||
{
|
||
VALUE_ADDRESS (v) = SYMBOL_VALUE_ADDRESS (msym);
|
||
}
|
||
|
||
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 field FIELDNO of the specified TYPE, from the anonymous object at
|
||
VALADDR.
|
||
|
||
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_field_as_long (struct type *type, const gdb_byte *valaddr, int fieldno)
|
||
{
|
||
ULONGEST val;
|
||
ULONGEST valmask;
|
||
int bitpos = TYPE_FIELD_BITPOS (type, fieldno);
|
||
int bitsize = TYPE_FIELD_BITSIZE (type, fieldno);
|
||
int lsbcount;
|
||
struct type *field_type;
|
||
|
||
val = extract_unsigned_integer (valaddr + bitpos / 8, sizeof (val));
|
||
field_type = TYPE_FIELD_TYPE (type, fieldno);
|
||
CHECK_TYPEDEF (field_type);
|
||
|
||
/* Extract bits. See comment above. */
|
||
|
||
if (BITS_BIG_ENDIAN)
|
||
lsbcount = (sizeof val * 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);
|
||
}
|
||
|
||
/* 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 (gdb_byte *addr, LONGEST fieldval, int bitpos, int bitsize)
|
||
{
|
||
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);
|
||
|
||
/* Shifting for bit field depends on endianness of the target machine. */
|
||
if (BITS_BIG_ENDIAN)
|
||
bitpos = sizeof (oword) * 8 - bitpos - bitsize;
|
||
|
||
oword &= ~(mask << bitpos);
|
||
oword |= fieldval << bitpos;
|
||
|
||
store_unsigned_integer (addr, sizeof oword, oword);
|
||
}
|
||
|
||
/* Pack NUM into BUF using a target format of TYPE. */
|
||
|
||
void
|
||
pack_long (gdb_byte *buf, struct type *type, LONGEST num)
|
||
{
|
||
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, 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), type, addr);
|
||
return val;
|
||
}
|
||
|
||
|
||
/* Create a value for a string constant to be stored locally
|
||
(not in the inferior's memory space, but in GDB memory).
|
||
This is analogous to value_from_longest, which also does not
|
||
use inferior memory. String shall NOT contain embedded nulls. */
|
||
|
||
struct value *
|
||
value_from_string (char *ptr)
|
||
{
|
||
struct value *val;
|
||
int len = strlen (ptr);
|
||
int lowbound = current_language->string_lower_bound;
|
||
struct type *string_char_type;
|
||
struct type *rangetype;
|
||
struct type *stringtype;
|
||
|
||
rangetype = create_range_type ((struct type *) NULL,
|
||
builtin_type_int,
|
||
lowbound, len + lowbound - 1);
|
||
string_char_type = language_string_char_type (current_language,
|
||
current_gdbarch);
|
||
stringtype = create_array_type ((struct type *) NULL,
|
||
string_char_type,
|
||
rangetype);
|
||
val = allocate_value (stringtype);
|
||
memcpy (value_contents_raw (val), ptr, len);
|
||
return val;
|
||
}
|
||
|
||
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 *
|
||
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)
|
||
{
|
||
arg = coerce_ref (arg);
|
||
if (current_language->c_style_arrays
|
||
&& TYPE_CODE (value_type (arg)) == TYPE_CODE_ARRAY)
|
||
arg = value_coerce_array (arg);
|
||
if (TYPE_CODE (value_type (arg)) == TYPE_CODE_FUNC)
|
||
arg = value_coerce_function (arg);
|
||
return arg;
|
||
}
|
||
|
||
struct value *
|
||
coerce_number (struct value *arg)
|
||
{
|
||
arg = coerce_array (arg);
|
||
arg = coerce_enum (arg);
|
||
return arg;
|
||
}
|
||
|
||
struct value *
|
||
coerce_enum (struct value *arg)
|
||
{
|
||
if (TYPE_CODE (check_typedef (value_type (arg))) == TYPE_CODE_ENUM)
|
||
arg = value_cast (builtin_type_unsigned_int, arg);
|
||
return arg;
|
||
}
|
||
|
||
|
||
/* Should we use DEPRECATED_EXTRACT_STRUCT_VALUE_ADDRESS instead of
|
||
gdbarch_extract_return_value? GCC_P is true if compiled with gcc and TYPE
|
||
is the type (which is known to be struct, union or array).
|
||
|
||
On most machines, the struct convention is used unless we are
|
||
using gcc and the type is of a special size. */
|
||
/* As of about 31 Mar 93, GCC was changed to be compatible with the
|
||
native compiler. GCC 2.3.3 was the last release that did it the
|
||
old way. Since gcc2_compiled was not changed, we have no
|
||
way to correctly win in all cases, so we just do the right thing
|
||
for gcc1 and for gcc2 after this change. Thus it loses for gcc
|
||
2.0-2.3.3. This is somewhat unfortunate, but changing gcc2_compiled
|
||
would cause more chaos than dealing with some struct returns being
|
||
handled wrong. */
|
||
/* NOTE: cagney/2004-06-13: Deleted check for "gcc_p". GCC 1.x is
|
||
dead. */
|
||
|
||
int
|
||
generic_use_struct_convention (int gcc_p, struct type *value_type)
|
||
{
|
||
return !(TYPE_LENGTH (value_type) == 1
|
||
|| TYPE_LENGTH (value_type) == 2
|
||
|| TYPE_LENGTH (value_type) == 4
|
||
|| TYPE_LENGTH (value_type) == 8);
|
||
}
|
||
|
||
/* 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). GCC_P is nonzero if compiled
|
||
with GCC. */
|
||
|
||
int
|
||
using_struct_return (struct type *value_type, int gcc_p)
|
||
{
|
||
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 (current_gdbarch, 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."));
|
||
}
|