PR symtab/25470 points out that the Zig programming language allows
integers of various bit sizes (including zero), not just sizes that
are a multiple of 8.
This is supported in DWARF by applying both a byte size and a
DW_AT_bit_size.
This patch adds support for this feature to integer and boolean types.
Other base types are not handled -- for floating-point types, this
didn't seem to make sense, and for character types I didn't see much
need. (These can be added later if desired.)
I've also added support for DW_AT_data_bit_offset at the same time. I
don't know whether the Zig compiler requires this, but it was
described in the same section in the DWARF standard and was easy to
add.
A new test case is supplied, using the DWARF assembler.
gdb/ChangeLog
2020-09-23 Tom Tromey <tom@tromey.com>
PR symtab/25470:
* value.c (unpack_long, pack_long, pack_unsigned_long): Handle bit
offset and bit size.
* printcmd.c (print_scalar_formatted): Handle zero-length
integer.
(print_scalar_formatted): Use bit_size_differs_p.
* gdbtypes.h (enum type_specific_kind) <TYPE_SPECIFIC_INT>: New
constant.
(union type_specific): <int_stuff>: New member.
(struct type) <bit_size_differs_p, bit_size, bit_offset>: New
methods.
* gdbtypes.c (init_integer_type, init_boolean_type): Initialize
TYPE_SPECIFIC_FIELD.
(recursive_dump_type, copy_type_recursive): Update.
* dwarf2/read.c (read_base_type): Handle DW_AT_bit_size and
DW_AT_data_bit_offset.
gdb/testsuite/ChangeLog
2020-09-23 Tom Tromey <tom@tromey.com>
* gdb.dwarf2/intbits.exp: New file.
* gdb.dwarf2/intbits.c: New file.
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