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Re: [gcov] a few improvements
On Mon, Jun 4, 2012 at 12:49 AM, Nathan Sidwell <nathan@acm.org> wrote:
> On 06/03/12 21:40, Xinliang David Li wrote:
>
>>> Can you explain this more -- what exactly are trying to do? ?Are you
>>> trying
>>> to rebuild multiple times with the same coverage data,
>>
>>
>> yes -- for instance, in the context of debugging a compiler problem,
>> you will need to compile the same file multiple times with the same
>> coverage data.
>
>
> ok, debugging the compiler is not the typical user mode of use.
Another usage is FDO performance tuning trying build with different
options/parameters, so it is common.
>
> Do any of the following work for you?
> *) don't use -frandom-seed (you don't say why you're using this flag)
This is in our build system for build reproducibility.
> *) copy and restore the coverage data file
> *) stub out the unlink code at the end of coverage.c. (I presume that you're
> rebuilding cc1 with optimization off anyway, and as you're debugging a
> compiler problem with FDO you're somewhat familiar with coverage.c).
I know how to workaround/fix the problem --- I am asking the
motivation for deleting the coverage file? What does it buy us? This
looks like a regression in gcc4.7 to me.
thanks,
David
>
> nathan