On Fri, Aug 23, 2013 at 05:15:19PM +0200, 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. > > Looks good, though I think this could be merged into the main 4.7 format patch, > since without it, the 4.7 code will never be reached. Sure, I can merge these two patches. > > Also it is my understanding that there are some distribution-specific versions > of GCC that include the 4.7. gcov format code but report GCC version 4.6. With > the auto-detection code implemented like this, gcov-kernel won't work correctly. > For that purpose I've implemented a configuration option to allow users to > force a specific version of gcov format. Ah, I was not aware of this inconsistency in versioning. This raises a question if it would not be better to deal directly with version in the gcov_info instead of these config options. This would of course mean some kind of gcov operations callbacks per gcov version(you already mentioned the file operations approach). > > I'm attaching the corresponding patch below: > > --- > kernel: gcov: make data format configurable > > Make the format of the generated gcov data configurable. This may be > required for example for pre-4.7 GCCs that contain the 4.7 gcov data > format changes. > > Signed-off-by: Peter Oberparleiter <oberpar@xxxxxxxxxxxxxxxxxx> > --- > kernel/gcov/Kconfig | 30 ++++++++++++++++++++++++++++++ > kernel/gcov/Makefile | 21 +++++++++++++++++++-- > 2 files changed, 49 insertions(+), 2 deletions(-) > > --- a/kernel/gcov/Kconfig > +++ b/kernel/gcov/Kconfig > @@ -46,4 +46,34 @@ config GCOV_PROFILE_ALL > larger and run slower. Also be sure to exclude files from profiling > which are not linked to the kernel image to prevent linker errors. > > +choice > + prompt "Specify GCOV format" > + depends on GCOV_KERNEL > + default GCOV_FORMAT_AUTODETECT > + ---help--- > + The gcov format is usually determined by the GCC version, but there are > + exceptions where format changes are integrated in lower-version GCCs. > + In such a case use this option to adjust the format used in the kernel > + accordingly. > + > + If unsure, choose "Autodetect". > + > +config GCOV_FORMAT_AUTODETECT > + bool "Autodetect" > + ---help--- > + Select this option to use the format that corresponds to your GCC > + version. > + > +config GCOV_FORMAT_3_4 > + bool "GCC 3.4 format" > + ---help--- > + Select this option to use the format defined by GCC 3.4. > + > +config GCOV_FORMAT_4_7 > + bool "GCC 4.7 format" > + ---help--- > + Select this option to use the format defined by GCC 4.7. > + > +endchoice > + > endmenu > --- a/kernel/gcov/Makefile > +++ b/kernel/gcov/Makefile > @@ -1,5 +1,22 @@ > ccflags-y := -DSRCTREE='"$(srctree)"' -DOBJTREE='"$(objtree)"' > > +# if-lt > +# Usage VAR := $(call if-lt, $(a), $(b)) > +# Returns 1 if (a < b) > +if-lt = $(shell [ $(1) -lt $(2) ] && echo 1) > + > +ifeq ($(CONFIG_GCOV_FORMAT_3_4),y) > + cc-ver := 0304 > +else ifeq ($(CONFIG_GCOV_FORMAT_4_7),y) > + cc-ver := 0407 > +else > + cc-ver := $(call cc-version) > +endif > + > obj-$(CONFIG_GCOV_KERNEL) := base.o fs.o > -obj-$(CONFIG_GCOV_KERNEL) += $(call cc-ifversion, -lt, 0407, gcc_3_4.o) > -obj-$(CONFIG_GCOV_KERNEL) += $(call cc-ifversion, -ge, 0407, gcc_4_7.o) > + > +ifeq ($(call if-lt, $(cc-ver), 0407),1) > + obj-$(CONFIG_GCOV_KERNEL) += gcc_3_4.o > +else > + obj-$(CONFIG_GCOV_KERNEL) += gcc_4_7.o > +endif > > > -- > Peter Oberparleiter > Linux on System z Development - IBM Germany > -- Frantisek Hrbata -- 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
