gdb/gdb-rhbz1420304-s390x-18of3...

167 lines
5.4 KiB
Diff

commit 359b19bb24d048750aa5367ad56a33267300d1a8
Author: Andreas Arnez <arnez@linux.vnet.ibm.com>
Date: Tue Jun 13 15:20:28 2017 +0200
write_pieced_value: Transfer least significant bits into bit-field
On big-endian targets, when targeting a bit-field, write_pieced_value
currently transfers the source value's *most* significant bits to the
target value, instead of its least significant bits. This is fixed.
In particular the fix adjusts the initial value of 'offset', which can now
potentially be nonzero. Thus the variable 'type_len' is renamed to
'max_offset', to avoid confusion. And for consistency, the affected logic
that was mirrored in read_pieced_value is changed there in the same way.
gdb/ChangeLog:
* dwarf2loc.c (write_pieced_value): When writing to a bit-field,
transfer the source value's least significant bits, instead of its
lowest-addressed ones. Rename type_len to max_offset.
(read_pieced_value): Mirror above changes to write_pieced_value as
applicable.
### a/gdb/ChangeLog
### b/gdb/ChangeLog
## -1,5 +1,13 @@
2017-06-13 Andreas Arnez <arnez@linux.vnet.ibm.com>
+ * dwarf2loc.c (write_pieced_value): When writing to a bit-field,
+ transfer the source value's least significant bits, instead of its
+ lowest-addressed ones. Rename type_len to max_offset.
+ (read_pieced_value): Mirror above changes to write_pieced_value as
+ applicable.
+
+2017-06-13 Andreas Arnez <arnez@linux.vnet.ibm.com>
+
* dwarf2loc.c (write_pieced_value): In DWARF_VALUE_MEMORY,
truncate full bytes from dest_offset_bits before using it as an
offset into the buffer.
--- a/gdb/dwarf2loc.c
+++ b/gdb/dwarf2loc.c
@@ -1756,12 +1756,11 @@ static void
read_pieced_value (struct value *v)
{
int i;
- long offset = 0;
+ LONGEST offset = 0, max_offset;
ULONGEST bits_to_skip;
gdb_byte *contents;
struct piece_closure *c
= (struct piece_closure *) value_computed_closure (v);
- size_t type_len;
size_t buffer_size = 0;
std::vector<gdb_byte> buffer;
int bits_big_endian
@@ -1778,12 +1777,12 @@ read_pieced_value (struct value *v)
{
bits_to_skip += (8 * value_offset (value_parent (v))
+ value_bitpos (v));
- type_len = value_bitsize (v);
+ max_offset = value_bitsize (v);
}
else
- type_len = 8 * TYPE_LENGTH (value_type (v));
+ max_offset = 8 * TYPE_LENGTH (value_type (v));
- for (i = 0; i < c->n_pieces && offset < type_len; i++)
+ for (i = 0; i < c->n_pieces && offset < max_offset; i++)
{
struct dwarf_expr_piece *p = &c->pieces[i];
size_t this_size, this_size_bits;
@@ -1798,20 +1797,13 @@ read_pieced_value (struct value *v)
bits_to_skip -= this_size_bits;
continue;
}
- if (bits_to_skip > 0)
- {
- dest_offset_bits = 0;
- source_offset_bits = bits_to_skip;
- this_size_bits -= bits_to_skip;
- bits_to_skip = 0;
- }
- else
- {
- dest_offset_bits = offset;
- source_offset_bits = 0;
- }
- if (this_size_bits > type_len - offset)
- this_size_bits = type_len - offset;
+ source_offset_bits = bits_to_skip;
+ this_size_bits -= bits_to_skip;
+ bits_to_skip = 0;
+ dest_offset_bits = offset;
+
+ if (this_size_bits > max_offset - offset)
+ this_size_bits = max_offset - offset;
this_size = (this_size_bits + source_offset_bits % 8 + 7) / 8;
source_offset = source_offset_bits / 8;
@@ -1932,12 +1924,11 @@ static void
write_pieced_value (struct value *to, struct value *from)
{
int i;
- long offset = 0;
ULONGEST bits_to_skip;
+ LONGEST offset = 0, max_offset;
const gdb_byte *contents;
struct piece_closure *c
= (struct piece_closure *) value_computed_closure (to);
- size_t type_len;
size_t buffer_size = 0;
std::vector<gdb_byte> buffer;
int bits_big_endian
@@ -1949,12 +1940,20 @@ write_pieced_value (struct value *to, struct value *from)
{
bits_to_skip += (8 * value_offset (value_parent (to))
+ value_bitpos (to));
- type_len = value_bitsize (to);
- }
+ /* Use the least significant bits of FROM. */
+ if (gdbarch_byte_order (get_type_arch (value_type (from)))
+ == BFD_ENDIAN_BIG)
+ {
+ max_offset = 8 * TYPE_LENGTH (value_type (from));
+ offset = max_offset - value_bitsize (to);
+ }
+ else
+ max_offset = value_bitsize (to);
+ }
else
- type_len = 8 * TYPE_LENGTH (value_type (to));
+ max_offset = 8 * TYPE_LENGTH (value_type (to));
- for (i = 0; i < c->n_pieces && offset < type_len; i++)
+ for (i = 0; i < c->n_pieces && offset < max_offset; i++)
{
struct dwarf_expr_piece *p = &c->pieces[i];
size_t this_size_bits, this_size;
@@ -1968,20 +1967,13 @@ write_pieced_value (struct value *to, struct value *from)
bits_to_skip -= this_size_bits;
continue;
}
- if (bits_to_skip > 0)
- {
- dest_offset_bits = bits_to_skip;
- source_offset_bits = 0;
- this_size_bits -= bits_to_skip;
- bits_to_skip = 0;
- }
- else
- {
- dest_offset_bits = 0;
- source_offset_bits = offset;
- }
- if (this_size_bits > type_len - offset)
- this_size_bits = type_len - offset;
+ dest_offset_bits = bits_to_skip;
+ this_size_bits -= bits_to_skip;
+ bits_to_skip = 0;
+ source_offset_bits = offset;
+
+ if (this_size_bits > max_offset - offset)
+ this_size_bits = max_offset - offset;
this_size = (this_size_bits + dest_offset_bits % 8 + 7) / 8;
source_offset = source_offset_bits / 8;