Adding bit position to ptype
Commit Message
Hi, I am having trouble looking up field offsets when reading disassembled text.
So I add an extra field to ptype:
(gdb) ptype WebCore::FrameLoader
type = class WebCore::FrameLoader {
private:
WebCore::Frame *m_frame bitpos: 0;
WebCore::FrameLoaderClient *m_client bitpos: 32;
WebCore::PolicyChecker m_policyChecker bitpos: 64;
WebCore::HistoryController m_history bitpos: 3264;
WebCore::ResourceLoadNotifier m_notifer bitpos: 3552;
WebCore::SubframeLoader m_subframeLoader bitpos: 3584;
WebCore::FrameLoaderStateMachine m_stateMachine bitpos: 3680;
WebCore::IconController m_icon bitpos: 3712;
...
That helps me a lot to understand what "ldr r0, [r4, #408]" means.
---
gdb/c-typeprint.c | 6 ++++++
1 file changed, 6 insertions(+)
Comments
>>>>> ">" == lin zuojian <manjian2006@gmail.com> writes:
>> Hi, I am having trouble looking up field offsets when reading
>> disassembled text. So I add an extra field to ptype:
Nice.
You might be interested in pahole.py.
>> diff --git a/gdb/c-typeprint.c b/gdb/c-typeprint.c
>> index 4edc9ec..9fbbc36 100644
>> --- a/gdb/c-typeprint.c
>> +++ b/gdb/c-typeprint.c
>> @@ -1110,6 +1110,12 @@ c_type_print_base (struct type *type, struct ui_file *stream,
>> fprintf_filtered (stream, " : %d",
>> TYPE_FIELD_BITSIZE (type, i));
>> }
>> + else if (!field_is_static (&TYPE_FIELD (type, i)))
>> + {
>> + /* print the bit pos. */
>> + fprintf_filtered (stream, " bitpos: %d",
>> + TYPE_FIELD_BITPOS (type, i));
>> + }
>> fprintf_filtered (stream, ";\n");
To be considered for acceptance all patches require a ChangeLog entry
and must pass regression testing -- which this one probably does not, as
it changes gdb's output by default. Please see the contribution
instructions.
I think it would probably be better to add a flag to ptype to enable
this behavior. Integrating all of the pahole behavior into ptype would
be even better, though I understand if you don't want to go this far.
thanks,
Tom
Hi Tom,
Before posting the second patch, I may make your point clear first.
Do you want me to add a flag to control this behavior?
Thanks
--
Lin Zuojian
>>>>> ">" == lin zuojian <manjian2006@gmail.com> writes:
>> Before posting the second patch, I may make your point clear first.
>> Do you want me to add a flag to control this behavior?
Yeah, I think the behavior should be optional and should default to
"off".
I think it's best to consider this as a new feature -- so it would need
a new ptype flag, documentation, NEWS entry, and tests. The bad news is
that this is much more work for you. That's probably why nobody has
implemented it before.
Tom
@@ -1110,6 +1110,12 @@ c_type_print_base (struct type *type, struct ui_file *stream,
fprintf_filtered (stream, " : %d",
TYPE_FIELD_BITSIZE (type, i));
}
+ else if (!field_is_static (&TYPE_FIELD (type, i)))
+ {
+ /* print the bit pos. */
+ fprintf_filtered (stream, " bitpos: %d",
+ TYPE_FIELD_BITPOS (type, i));
+ }
fprintf_filtered (stream, ";\n");
}