On Sun, Feb 28, 2010 at 4:56 PM, H.J. Lu <hjl.tools@gmail.com> wrote:
> On Sun, Feb 28, 2010 at 4:15 PM, H.J. Lu <hjl.tools@gmail.com> wrote:
>> On Mon, Feb 22, 2010 at 8:45 AM, Daniel Jacobowitz <dan@codesourcery.com> wrote:
>>> Hi H.J.,
>>>
>>> This patch adds <flags> support to the XML language.  Could you try
>>> using this to move the two x86 flags registers from out of
>>> target-descriptions.c?
>>>
>>> The flags support is straightforward and covered by the manual.
>>> It's not tested because I couldn't find a way to do so; you can't
>>> ptype a flags register, and you can't add dummy registers whose value
>>> you can get at, only for ptype.
>>>
>>> The patch also adds <struct>, which is a little more interesting.
>>> It's got two forms:
>>>
>>> * Register containing integer bitfields.  Each field must be
>>> explicitly positioned.  The size must be pre-declared - otherwise
>>> the representation GDB uses for big-endian bitfields can't figure out
>>> how far from the MSB edge of the register the field is.
>>>
>>> * Register containing typed non-bitfield structures.  Each field must
>>> be implicitly positioned.  There's no support for padding.
>>>
>>> These are somewhat annoying limitations, but they suffice for
>>> everything I've needed this for since I wrote the patch, which was
>>> originally several years ago; it's been stuck in my submission queue
>>> because it was tangled up with other local patches.  Since they are
>>> "must" restrictions, they are easy to lift in the future; we can make
>>> GDB more permissive.
>>>
>>> These I was able to type, although I'd have liked more exhaustive
>>> tests... for that, I'd need typeof, which turns out to be annoyingly
>>> hard to implement in GDB's parser :-(
>>>
>>> Eli, how's the documentation?
>>>
>>> --
>>> Daniel Jacobowitz
>>> CodeSourcery
>>>
>>> 2010-02-22  Daniel Jacobowitz  <dan@codesourcery.com>
>>>
>>>        * gdbtypes.c (append_composite_type_field_raw): New.
>>>        (append_composite_type_field_aligned): Use the new function.
>>>        * gdbtypes.h (append_composite_type_field_raw): Declare.
>>>        * target-descriptions.c (struct tdesc_type_field): Add start and end.
>>>        (struct tdesc_type_flag): New type.
>>>        (struct tdesc_type): Add TDESC_TYPE_STRUCT and TDESC_TYPE_FLAGS to
>>>        kind.  Add size to u.u.  Add u.f for flags.
>>>        (tdesc_gdb_type): Handle TDESC_TYPE_STRUCT and TDESC_TYPE_FLAGS.
>>>        (tdesc_free_type): Likewise.
>>>        (tdesc_create_struct, tdesc_set_struct_size, tdesc_create_flags): New.
>>>        (tdesc_add_field): Handle TDESC_TYPE_STRUCT.
>>>        (tdesc_add_bitfield, tdesc_add_flag): New.
>>>        * target-descriptions.h (tdesc_create_struct, tdesc_set_struct_size)
>>>        (tdesc_create_flags, tdesc_add_bitfield, tdesc_add_flag): Declare.
>>>        * xml-tdesc.c (struct tdesc_parsing_data): Rename current_union to
>>>        current_type.  Add current_type_size and current_type_is_flags.
>>>        (tdesc_start_union): Clear the new fields.
>>>        (tdesc_start_struct, tdesc_start_flags): New.
>>>        (tdesc_start_field): Handle struct fields, including bitfields.
>>>        (field_attributes): Make type optional.  Add start and end.
>>>        (union_children): Rename to struct_union_children.
>>>        (union_attributes): Rename to struct_union_attributes.  Add optional
>>>        size.
>>>        (flags_attributes): New.
>>>        (feature_children): Add struct and flags.
>>>        * features/gdb-target.dtd: Add flags and struct to features.
>>>        Make field type optional.  Add field start and end.
>>>
>>>        * gdb.texinfo (Types): Describe <struct> and <flags>.
>>>
>>>        * gdb.xml/extra-regs.xml: Add struct1, struct2, and flags
>>>        types.  Add structreg, bitfields, and flags registers.
>>>        * gdb.xml/tdesc-regs.exp: Test structreg and bitfields
>>>        registers.
>>>
>>
>> It doesn't work. "case TDESC_TYPE_FLAGS:" is missing in
>> maint_print_c_tdesc_cmd.
>>
>>
>
> This patch makes it to work. However, there is no equivalent of
>
> append_flags_type_flag (type, 1, NULL);
>
> I have
>
>  <flags id="i386_eflags" size="4">
>    <field name="CF" start="0" end="0"/>
>    <field name="" start="1" end="1"/>
>    <field name="PF" start="2" end="2"/>
> ....
>
> I got
>
> (gdb) p $eflags
> $1 = [  PF ZF IF ]
>           ^ extra white space
> (gdb)
>
> instead of
> (gdb) p $eflags
> $1 = [ PF ZF IF ]
> (gdb)
>

Hi Daniel,

This patch on top of yours works.

Thanks.


-- 
H.J.