Re: [RFC] libgcov.c re-factoring and offline profile-tool

[Xinliang David Li <davidxl at google dot com>]

On Fri, Nov 8, 2013 at 10:56 AM, Rong Xu <xur@google.com> wrote:
> A question about inhibit_libc.
> When inhibit_libc is defined, we provide dummy functions for all the
> __gcov_* methods.
> Is it purposely to minimize the footprint?
> I'm thinking to allow some codes that are independent of libc (and its
> headers) under this. Is it OK?
>


I only saw the macro defined for mcore targets -- not sure if they are
obsolete or not.

David


> -Rong
>
> On Fri, Nov 8, 2013 at 10:48 AM, Rong Xu <xur@google.com> wrote:
>> On Fri, Nov 8, 2013 at 10:22 AM, Xinliang David Li <davidxl@google.com> wrote:
>>> in libgcov-driver.c
>>>
>>>> /* Flag when the profile has already been dumped via __gcov_dump().  */
>>>> static int gcov_dump_complete;
>>>
>>>> inline void
>>>> set_gcov_dump_complete (void)
>>>>{
>>>   > gcov_dump_complete = 1;
>>>>}
>>>
>>>>inline void
>>>>reset_gcov_dump_complete (void)
>>>>{
>>>>  gcov_dump_complete = 0;
>>>>}
>>>
>>>
>>> These should be moved to libgcov-interface.c. Is there reason to not
>>> mark them as static?
>>
>> gcov_dump_complete is used in gcov_exit() which is in
>> libgcov-driver.c, but it's set in __gcov_dump and __gcov_reset, both
>> in libgcov-interface.c.
>> I want gcov_dump_complete a static. So I have to add to global
>> functions that accessible from libgcov-interface.c.
>> Another choice is to move __gcov_dump and __gcov_reset to
>> libgcov-driver.c and that will simplify the code.
>>
>>>
>>> in libgcov-profiler.c, line 142
>>>
>>>> #if defined(HAVE_CC_TLS) && !defined (USE_EMUTLS)
>>>> __thread
>>>
>>> trailing whilte space.
>>>
>>
>> Will fix.
>>
>>>
>>>>     || (VTABLE_USES_DESCRIPTORS && __gcov_indirect_call_callee
>>>>         && *(void **) cur_func == *(void **) __gcov_indirect_call_callee))
>>>
>>> trailing white space.
>>>
>>
>> Will fix.
>>
>>>
>>> in libgcov-merge.c
>>>
>>> 1) I don't think you need in_mem flag. For in memory merge, the source != NULL.
>>> 2) document the new source and weight parameter -- especially the weight.
>>
>> Will do.
>>
>>> 3) How do you deal with integer overflow ?
>>
>> This is good question. gcvo_type is (typically) long long. I thought
>> the count value will not be nearly close to the max of long long.
>> (We did see overflow in compiler, but that's because of the scaling --
>> some of the scaling factors are really large.)
>>
>>>
>>> David
>>>
>>>
>>>
>>>
>>>
>>>
>>> On Thu, Nov 7, 2013 at 3:34 PM, Rong Xu <xur@google.com> wrote:
>>>> On Thu, Nov 7, 2013 at 9:40 AM, Joseph S. Myers <joseph@codesourcery.com> wrote:
>>>>> On Thu, 7 Nov 2013, Rong Xu wrote:
>>>>>
>>>>>> Thanks Joseph for these detailed comments/suggestions.
>>>>>> The fixed patch is attached to this email.
>>>>>> The only thing left out is the Texinfo manual. Do you mean this tool
>>>>>> should have its it's own texi file in gcc/doc?
>>>>>
>>>>> Its own texi file, probably included as a chapter by gcc.texi (like
>>>>> gcov.texi is).
>>>>
>>>> OK. will add this in.
>>>>
>>>> My last patch that changes the command handling is actually broken.
>>>> Please ignore that patch and use the one in this email.
>>>>
>>>> Also did some minor adjust of the code in libgcov.
>>>>
>>>> Thanks,
>>>>
>>>> -Rong
>>>>
>>>>
>>>>>
>>>>> --
>>>>> Joseph S. Myers
>>>>> joseph@codesourcery.com