Imagelibrary/binutils-gdb
1
0
Fork 1
mirror of https://github.com/bminor/binutils-gdb.git synced 2025-12-27 17:40:49 +00:00
Code Issues Packages Projects Releases Wiki Activity

Introduce apply_bit_offset_to_field helper function

Browse Source 
This patch makes a new function, apply_bit_offset_to_field, that is
used to handle the logic of DW_AT_bit_offset.  Currently there is just
a single caller, but the next patch will change this.
This commit is contained in:
Tom Tromey
2025-04-18 08:54:52 -06:00
parent 1d9fb3ba19
commit ee580641bc
3 changed files with 72 additions and 40 deletions
Download Patch File Download Diff File Expand all files Collapse all files

51
gdb/dwarf2/read.c
View File

@@ -9940,8 +9940,6 @@ static void
dwarf2_add_field (struct field_info *fip, struct die_info *die,
struct dwarf2_cu *cu)
{
struct objfile *objfile = cu->per_objfile->objfile;
struct gdbarch *gdbarch = objfile->arch ();
struct nextfield *new_field;
struct attribute *attr;
struct field *fp;
@@ -10008,46 +10006,19 @@ dwarf2_add_field (struct field_info *fip, struct die_info *die,
attr = dwarf2_attr (die, DW_AT_bit_offset, cu);
if (attr != nullptr && attr->form_is_constant ())
{
ULONGEST bit_offset = attr->unsigned_constant ().value_or (0);
if (gdbarch_byte_order (gdbarch) == BFD_ENDIAN_BIG)
{
/* For big endian bits, the DW_AT_bit_offset gives the
additional bit offset from the MSB of the containing
anonymous object to the MSB of the field. We don't
have to do anything special since we don't need to
know the size of the anonymous object. */
fp->set_loc_bitpos (fp->loc_bitpos () + bit_offset);
}
else
{
/* For little endian bits, compute the bit offset to the
MSB of the anonymous object, subtract off the number of
bits from the MSB of the field to the MSB of the
object, and then subtract off the number of bits of
the field itself. The result is the bit offset of
the LSB of the field. */
int anonymous_size;
LONGEST bit_offset = attr->unsigned_constant ().value_or (0);
attr = dwarf2_attr (die, DW_AT_byte_size, cu);
if (attr != nullptr && attr->form_is_constant ())
{
/* The size of the anonymous object containing
the bit field is explicit, so use the
indicated size (in bytes). */
anonymous_size = attr->unsigned_constant ().value_or (0);
}
else
{
/* The size of the anonymous object containing
the bit field must be inferred from the type
attribute of the data member containing the
bit field. */
anonymous_size = fp->type ()->length ();
}
fp->set_loc_bitpos (fp->loc_bitpos ()
+ anonymous_size * bits_per_byte
- bit_offset - fp->bitsize ());
LONGEST anonymous_size = 0;
attr = dwarf2_attr (die, DW_AT_byte_size, cu);
if (attr != nullptr && attr->form_is_constant ())
{
/* The size of the anonymous object containing
the bit field is explicit, so use the
indicated size (in bytes). */
anonymous_size = attr->unsigned_constant ().value_or (0);
}
apply_bit_offset_to_field (*fp, bit_offset, anonymous_size);
}
/* Get name of field. */