On 12/02/2014 07:43 PM, Michael Ellerman wrote: > On Tue, 2014-12-02 at 19:36 -0800, Tim Bird wrote: >> This test shows the amount of memory used by the system. >> Note that this is dependent on the user-space that is loaded >> when this program runs. Optimally, this program would be >> run as the init program itself. > > Sorry to only chime in at v5. > >> diff --git a/tools/testing/selftests/size/Makefile b/tools/testing/selftests/size/Makefile >> new file mode 100644 >> index 0000000..47f8e9c >> --- /dev/null >> +++ b/tools/testing/selftests/size/Makefile >> @@ -0,0 +1,15 @@ >> +#ifndef CC >> + CC = $(CROSS_COMPILE)gcc >> +#endif > > I think the following is preferable: > > CC := $(CROSS_COMPILE)$(CC) > > > It allows optionally setting a custom CC, as well as optionally CROSS_COMPILE. I'm not sure I follow this. If CC is unset, you get only the CROSS_COMPILE prefix. If CC is set to e.g. 'gcc', then you get a nicely formatted toolchain string. But if CC already has the prefix applied, then this will result in having it duplicated, which surely won't work correctly. In the long run, I would hope that a higher level Makefile or environment setting will be setting the toolchain string appropriately (as well as handling build flags) which is why I wanted to use an ifndef (which Thomas correctly pointed out is just wrong). Actually, after getting this tiny program accepted, my next task was working on a proper fix for handling cross compilation in a more generic (not case-by-case) way. CROSS_COMPILE prefix usage looks a bit uncoordinated in the tools directory, but most tests seem to be favoring $(CROSS_COMPILE)gcc. $ cd tools ; mgrep CROSS ./vm/Makefile:CC = $(CROSS_COMPILE)gcc ./usb/Makefile:CC = $(CROSS_COMPILE)gcc ./testing/selftests/net/Makefile:CC = $(CROSS_COMPILE)gcc ./testing/selftests/vm/Makefile:CC = $(CROSS_COMPILE)gcc ./testing/selftests/efivarfs/Makefile:CC = $(CROSS_COMPILE)gcc ./testing/selftests/size/Makefile: CC = $(CROSS_COMPILE)gcc ./testing/selftests/powerpc/Makefile:CC := $(CROSS_COMPILE)$(CC) ./hv/Makefile:CC = $(CROSS_COMPILE)gcc ./perf/config/feature-checks/Makefile:CC := $(CROSS_COMPILE)gcc -MD ./perf/config/feature-checks/Makefile:PKG_CONFIG := $(CROSS_COMPILE)pkg-config ./lib/api/Makefile:CC = $(CROSS_COMPILE)gcc ./lib/api/Makefile:AR = $(CROSS_COMPILE)ar ./lib/lockdep/Makefile:# Allow setting CC and AR, or setting CROSS_COMPILE as a prefix. ./lib/lockdep/Makefile:$(call allow-override,CC,$(CROSS_COMPILE)gcc) ./lib/lockdep/Makefile:$(call allow-override,AR,$(CROSS_COMPILE)ar) ./lib/lockdep/Makefile:TRACK_CFLAGS = $(subst ','\'',$(CFLAGS)):$(ARCH):$(CROSS_COMPILE) ./lib/traceevent/Makefile:# Allow setting CC and AR, or setting CROSS_COMPILE as a prefix. ./lib/traceevent/Makefile:$(call allow-override,CC,$(CROSS_COMPILE)gcc) ./lib/traceevent/Makefile:$(call allow-override,AR,$(CROSS_COMPILE)ar) ./lib/traceevent/Makefile:TRACK_CFLAGS = $(subst ','\'',$(CFLAGS)):$(ARCH):$(CROSS_COMPILE) ./cgroup/Makefile:CC = $(CROSS_COMPILE)gcc ./power/acpi/Makefile:CROSS = #/usr/i386-linux-uclibc/usr/bin/i386-uclibc- ./power/acpi/Makefile:CC = $(CROSS)gcc ./power/acpi/Makefile:LD = $(CROSS)gcc ./power/acpi/Makefile:STRIP = $(CROSS)strip ./power/cpupower/Makefile:CROSS = #/usr/i386-linux-uclibc/usr/bin/i386-uclibc- ./power/cpupower/Makefile:CC = $(CROSS)gcc ./power/cpupower/Makefile:LD = $(CROSS)gcc ./power/cpupower/Makefile:AR = $(CROSS)ar ./power/cpupower/Makefile:STRIP = $(CROSS)strip ./power/cpupower/Makefile:RANLIB = $(CROSS)ranlib ./power/cpupower/Makefile:export CROSS CC AR STRIP RANLIB CFLAGS LDFLAGS LIB_OBJS ./power/x86/turbostat/Makefile:CC = $(CROSS_COMPILE)gcc I agree it's desirable not to hardcode gcc, but we seem to be doing it all over the place already. -- Tim -- To unsubscribe from this list: send the line "unsubscribe linux-api" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
