}
/* With SRC being a buffer containing BIT_SIZE bits of data at BIT_OFFSET,
- unpack that data into UNPACKED. UNPACKED_LEN is the size in bytes of
+ unpack that data into UNPACKED. UNPACKED_LEN is the size in bytes of
the unpacked buffer.
+ The size of the unpacked buffer (UNPACKED_LEN) is expected to be large
+ enough to contain at least BIT_OFFSET bits. If not, an error is raised.
+
IS_BIG_ENDIAN is nonzero if the data is stored in big endian mode,
zero otherwise.
the indices move. */
int delta = is_big_endian ? -1 : 1;
+ /* Make sure that unpacked is large enough to receive the BIT_SIZE
+ bits from SRC. .*/
+ if ((bit_size + HOST_CHAR_BIT - 1) / HOST_CHAR_BIT > unpacked_len)
+ error (_("Cannot unpack %d bits into buffer of %d bytes"),
+ bit_size, unpacked_len);
+
srcBitsLeft = bit_size;
src_bytes_left = src_len;
unpacked_bytes_left = unpacked_len;
struct type *type)
{
struct value *v;
- gdb_byte *src; /* First byte containing data to unpack */
- int src_len = (bit_size + bit_offset + HOST_CHAR_BIT - 1) / 8;
+ const gdb_byte *src; /* First byte containing data to unpack */
gdb_byte *unpacked;
- int is_scalar;
+ const int is_scalar = is_scalar_type (type);
+ const int is_big_endian = gdbarch_bits_big_endian (get_type_arch (type));
+ gdb_byte *staging = NULL;
+ int staging_len = 0;
+ struct cleanup *old_chain = make_cleanup (null_cleanup, NULL);
type = ada_check_typedef (type);
+ if (obj == NULL)
+ src = valaddr + offset;
+ else
+ src = value_contents (obj) + offset;
+
+ if (is_dynamic_type (type))
+ {
+ /* The length of TYPE might by dynamic, so we need to resolve
+ TYPE in order to know its actual size, which we then use
+ to create the contents buffer of the value we return.
+ The difficulty is that the data containing our object is
+ packed, and therefore maybe not at a byte boundary. So, what
+ we do, is unpack the data into a byte-aligned buffer, and then
+ use that buffer as our object's value for resolving the type. */
+ staging_len = (bit_size + HOST_CHAR_BIT - 1) / HOST_CHAR_BIT;
+ staging = (gdb_byte *) malloc (staging_len);
+ make_cleanup (xfree, staging);
+
+ ada_unpack_from_contents (src, bit_offset, bit_size,
+ staging, staging_len,
+ is_big_endian, has_negatives (type),
+ is_scalar);
+ type = resolve_dynamic_type (type, staging, 0);
+ if (TYPE_LENGTH (type) < (bit_size + HOST_CHAR_BIT - 1) / HOST_CHAR_BIT)
+ {
+ /* This happens when the length of the object is dynamic,
+ and is actually smaller than the space reserved for it.
+ For instance, in an array of variant records, the bit_size
+ we're given is the array stride, which is constant and
+ normally equal to the maximum size of its element.
+ But, in reality, each element only actually spans a portion
+ of that stride. */
+ bit_size = TYPE_LENGTH (type) * HOST_CHAR_BIT;
+ }
+ }
+
if (obj == NULL)
{
v = allocate_value (type);
- src = (gdb_byte *) valaddr + offset;
+ src = valaddr + offset;
}
else if (VALUE_LVAL (obj) == lval_memory && value_lazy (obj))
{
+ int src_len = (bit_size + bit_offset + HOST_CHAR_BIT - 1) / 8;
+ gdb_byte *buf;
+
v = value_at (type, value_address (obj) + offset);
- type = value_type (v);
- if (TYPE_LENGTH (type) * HOST_CHAR_BIT < bit_size)
- {
- /* This can happen in the case of an array of dynamic objects,
- where the size of each element changes from element to element.
- In that case, we're initially given the array stride, but
- after resolving the element type, we find that its size is
- less than this stride. In that case, adjust bit_size to
- match TYPE's length, and recompute LEN accordingly. */
- bit_size = TYPE_LENGTH (type) * HOST_CHAR_BIT;
- src_len = TYPE_LENGTH (type) + (bit_offset + HOST_CHAR_BIT - 1) / 8;
- }
- src = alloca (src_len);
- read_memory (value_address (v), src, src_len);
+ buf = (gdb_byte *) alloca (src_len);
+ read_memory (value_address (v), buf, src_len);
+ src = buf;
}
else
{
v = allocate_value (type);
- src = (gdb_byte *) value_contents (obj) + offset;
+ src = value_contents (obj) + offset;
}
if (obj != NULL)
}
else
set_value_bitsize (v, bit_size);
- unpacked = (gdb_byte *) value_contents (v);
+ unpacked = value_contents_writeable (v);
if (bit_size == 0)
{
memset (unpacked, 0, TYPE_LENGTH (type));
+ do_cleanups (old_chain);
return v;
}
- switch (TYPE_CODE (type))
+ if (staging != NULL && staging_len == TYPE_LENGTH (type))
{
- case TYPE_CODE_ARRAY:
- case TYPE_CODE_UNION:
- case TYPE_CODE_STRUCT:
- is_scalar = 0;
- break;
- default:
- is_scalar = 1;
- break;
+ /* Small short-cut: If we've unpacked the data into a buffer
+ of the same size as TYPE's length, then we can reuse that,
+ instead of doing the unpacking again. */
+ memcpy (unpacked, staging, staging_len);
}
+ else
+ ada_unpack_from_contents (src, bit_offset, bit_size,
+ unpacked, TYPE_LENGTH (type),
+ is_big_endian, has_negatives (type), is_scalar);
- ada_unpack_from_contents (src, bit_offset, bit_size,
- unpacked, TYPE_LENGTH (type),
- gdbarch_bits_big_endian (get_type_arch (type)),
- has_negatives (type), is_scalar);
-
- if (is_dynamic_type (value_type (v)))
- v = value_from_contents_and_address (value_type (v), value_contents (v),
- 0);
+ do_cleanups (old_chain);
return v;
}
{
static char *result;
static size_t result_len = 0;
- char *tmp;
+ const char *tmp;
/* First, unqualify the enumeration name:
1. Search for the last '.' character. If we find one, then skip
projects / deliverable / binutils-gdb.git / blobdiff