/* Low level packing and unpacking of values for GDB, the GNU Debugger.
- Copyright (C) 1986, 1987, 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995,
- 1996, 1997, 1998, 1999, 2000, 2002, 2003, 2004, 2005, 2006, 2007, 2008,
- 2009, 2010, 2011 Free Software Foundation, Inc.
+ Copyright (C) 1986-2000, 2002-2012 Free Software Foundation, Inc.
This file is part of GDB.
#include "python/python.h"
#include <ctype.h>
#include "tracepoint.h"
+#include "cp-abi.h"
/* Prototypes for exported functions. */
static struct cmd_list_element *functionlist;
+/* Note that the fields in this structure are arranged to save a bit
+ of memory. */
+
struct value
{
/* Type of value; either not an lval, or one of the various
enum lval_type lval;
/* Is it modifiable? Only relevant if lval != not_lval. */
- int modifiable;
+ unsigned int modifiable : 1;
+
+ /* If zero, contents of this value are in the contents field. If
+ nonzero, contents are in inferior. If the lval field is lval_memory,
+ the contents are in inferior memory at location.address plus offset.
+ The lval field may also be lval_register.
+
+ WARNING: This field is used by the code which handles watchpoints
+ (see breakpoint.c) to decide whether a particular value can be
+ watched by hardware watchpoints. If the lazy flag is set for
+ some member of a value chain, it is assumed that this member of
+ the chain doesn't need to be watched as part of watching the
+ value itself. This is how GDB avoids watching the entire struct
+ or array when the user wants to watch a single struct member or
+ array element. If you ever change the way lazy flag is set and
+ reset, be sure to consider this use as well! */
+ unsigned int lazy : 1;
+
+ /* If nonzero, this is the value of a variable which does not
+ actually exist in the program. */
+ unsigned int optimized_out : 1;
+
+ /* If value is a variable, is it initialized or not. */
+ unsigned int initialized : 1;
+
+ /* If value is from the stack. If this is set, read_stack will be
+ used instead of read_memory to enable extra caching. */
+ unsigned int stack : 1;
+
+ /* If the value has been released. */
+ unsigned int released : 1;
/* Location of value (if lval). */
union
gdbarch_bits_big_endian=1 targets, it is the position of the MSB. */
int bitpos;
+ /* The number of references to this value. When a value is created,
+ the value chain holds a reference, so REFERENCE_COUNT is 1. If
+ release_value is called, this value is removed from the chain but
+ the caller of release_value now has a reference to this value.
+ The caller must arrange for a call to value_free later. */
+ int reference_count;
+
/* Only used for bitfields; the containing value. This allows a
single read from the target when displaying multiple
bitfields. */
/* Register number if the value is from a register. */
short regnum;
- /* If zero, contents of this value are in the contents field. If
- nonzero, contents are in inferior. If the lval field is lval_memory,
- the contents are in inferior memory at location.address plus offset.
- The lval field may also be lval_register.
-
- WARNING: This field is used by the code which handles watchpoints
- (see breakpoint.c) to decide whether a particular value can be
- watched by hardware watchpoints. If the lazy flag is set for
- some member of a value chain, it is assumed that this member of
- the chain doesn't need to be watched as part of watching the
- value itself. This is how GDB avoids watching the entire struct
- or array when the user wants to watch a single struct member or
- array element. If you ever change the way lazy flag is set and
- reset, be sure to consider this use as well! */
- char lazy;
-
- /* If nonzero, this is the value of a variable which does not
- actually exist in the program. */
- char optimized_out;
-
- /* If value is a variable, is it initialized or not. */
- int initialized;
-
- /* If value is from the stack. If this is set, read_stack will be
- used instead of read_memory to enable extra caching. */
- int stack;
-
/* Actual contents of the value. Target byte-order. NULL or not
valid if lazy is nonzero. */
gdb_byte *contents;
rather than available, since the common and default case is for a
value to be available. This is filled in at value read time. */
VEC(range_s) *unavailable;
-
- /* The number of references to this value. When a value is created,
- the value chain holds a reference, so REFERENCE_COUNT is 1. If
- release_value is called, this value is removed from the chain but
- the caller of release_value now has a reference to this value.
- The caller must arrange for a call to value_free later. */
- int reference_count;
};
int
return value->parent;
}
+/* See value.h. */
+
+void
+set_value_parent (struct value *value, struct value *parent)
+{
+ value->parent = parent;
+}
+
gdb_byte *
value_contents_raw (struct value *value)
{
if (value->lval == lval_internalvar
|| value->lval == lval_internalvar_component)
return 0;
- return value->location.address + value->offset;
+ if (value->parent != NULL)
+ return value_address (value->parent) + value->offset;
+ else
+ return value->location.address + value->offset;
}
CORE_ADDR
for (val = all_values; val && val != mark; val = next)
{
next = val->next;
+ val->released = 1;
value_free (val);
}
all_values = val;
for (val = all_values; val; val = next)
{
next = val->next;
+ val->released = 1;
value_free (val);
}
{
all_values = val->next;
val->next = NULL;
+ val->released = 1;
return;
}
{
v->next = val->next;
val->next = NULL;
+ val->released = 1;
break;
}
}
}
+/* If the value is not already released, release it.
+ If the value is already released, increment its reference count.
+ That is, this function ensures that the value is released from the
+ value chain and that the caller owns a reference to it. */
+
+void
+release_value_or_incref (struct value *val)
+{
+ if (val->released)
+ value_incref (val);
+ else
+ release_value (val);
+}
+
/* Release all values up to mark */
struct value *
value_release_to_mark (struct value *mark)
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;
- }
+ {
+ if (next->next == mark)
+ {
+ all_values = next->next;
+ next->next = NULL;
+ return val;
+ }
+ next->released = 1;
+ }
all_values = 0;
return val;
}
/* This field is actually a base subobject, so preserve the
entire object's contents for later references to virtual
bases, etc. */
+ int boffset;
/* Lazy register values with offsets are not supported. */
if (VALUE_LVAL (arg1) == lval_register && value_lazy (arg1))
value_fetch_lazy (arg1);
+ /* We special case virtual inheritance here because this
+ requires access to the contents, which we would rather avoid
+ for references to ordinary fields of unavailable values. */
+ if (BASETYPE_VIA_VIRTUAL (arg_type, fieldno))
+ boffset = baseclass_offset (arg_type, fieldno,
+ value_contents (arg1),
+ value_embedded_offset (arg1),
+ value_address (arg1),
+ arg1);
+ else
+ boffset = TYPE_FIELD_BITPOS (arg_type, fieldno) / 8;
+
if (value_lazy (arg1))
v = allocate_value_lazy (value_enclosing_type (arg1));
else
}
v->type = type;
v->offset = value_offset (arg1);
- v->embedded_offset = (offset + value_embedded_offset (arg1)
- + TYPE_FIELD_BITPOS (arg_type, fieldno) / 8);
+ v->embedded_offset = offset + value_embedded_offset (arg1) + boffset;
}
else
{
/* Pack NUM into BUF using a target format of TYPE. */
-void
+static void
pack_unsigned_long (gdb_byte *buf, struct type *type, ULONGEST num)
{
int len;
return funcs->coerce_ref (arg);
}
+/* Look at value.h for description. */
+
+struct value *
+readjust_indirect_value_type (struct value *value, struct type *enc_type,
+ struct type *original_type,
+ struct value *original_value)
+{
+ /* Re-adjust type. */
+ deprecated_set_value_type (value, TYPE_TARGET_TYPE (original_type));
+
+ /* Add embedding info. */
+ set_value_enclosing_type (value, enc_type);
+ set_value_embedded_offset (value, value_pointed_to_offset (original_value));
+
+ /* We may be pointing to an object of some derived type. */
+ return value_full_object (value, NULL, 0, 0, 0);
+}
+
struct value *
coerce_ref (struct value *arg)
{
struct type *value_type_arg_tmp = check_typedef (value_type (arg));
struct value *retval;
+ struct type *enc_type;
retval = coerce_ref_if_computed (arg);
if (retval)
if (TYPE_CODE (value_type_arg_tmp) != TYPE_CODE_REF)
return arg;
- return value_at_lazy (TYPE_TARGET_TYPE (value_type_arg_tmp),
- unpack_pointer (value_type (arg),
- value_contents (arg)));
+ enc_type = check_typedef (value_enclosing_type (arg));
+ enc_type = TYPE_TARGET_TYPE (enc_type);
+
+ retval = value_at_lazy (enc_type,
+ unpack_pointer (value_type (arg),
+ value_contents (arg)));
+ return readjust_indirect_value_type (retval, enc_type,
+ value_type_arg_tmp, arg);
}
struct value *