On 24.08.2013 21:44, Frantisek Hrbata wrote: > On Fri, Aug 23, 2013 at 05:21:12PM +0200, Peter Oberparleiter wrote: >> On 23.08.2013 17:15, Peter Oberparleiter wrote: >>> On 23.08.2013 10:39, Frantisek Hrbata wrote: >>>> Compile the correct gcov implementation file for a specific gcc version. In >>>> the future, if another file is added, the conditions will need to be somehow >>>> adjusted to if-elif-else case, but at this point the simple cc-ifversion should >>>> be enough. >> >> As promised, I'm also adding the patch that makes the format-specific part >> of gcov-kernel a loadable kernel module: >> >> --- >> kernel: gcov: make format-specific code loadable >> >> Turn the format-specific part of gcov-kernel into a loadable kernel >> module. This enables the use of gcov-kernel with kernel modules >> that were compiled with a version of GCC that produces a different >> gcov format when compared to the version of GCC that was used to >> compile the kernel. > > If I understand it correctly, this would mean that you will be able to use only > one implementation of gcov format at the time. Meaning you will be able to get > coverage data for module, but not for kernel if it was compiled with different > gcc(gcda format). This is probably ok if you work only on your module, but I'm > not sure this is generally the right approach. In this case I would probably > rather see some support for more gcov formats at the same time(e.g. set of > callback operations per gcov version). Again I'm probably missing something, but > I still cannot see reason why to add such feature. If you want gcov support just > compile your kernel and modules with the same gcc version(gcda format). But if > this is really needed maybe it would be better to consider some parallel support > for more gcov formats based on the gcov_info version. The callback approach has other drawbacks (see previous mail). > Would it be possible to add support for the modified gcc 4.7 gcov format and > deal with this later? I can incorporate your changes: iter to use buffer, > .init_array for modules and possibility to explicitly select the gcda format. > In this case we will have at least the basic support in kernel. This is just me > thinking out loud. I think that's an approach I can live with. Maybe the need for a multi-version support will surface again later in a more refined form, but until then there should be no reason to delay base GCC 4.7 support any further. -- Peter Oberparleiter Linux on System z Development - IBM Germany -- To unsubscribe from this list: send the line "unsubscribe linux-arch" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
