On Sun, Jul 4, 2021 at 7:03 PM Masahiro Yamada <masahiroy@xxxxxxxxxx> wrote: > > On Fri, Jul 2, 2021 at 12:29 PM Lecopzer Chen > <lecopzer.chen@xxxxxxxxxxxx> wrote: > > > > To check the GNU make version. Used by the LTO Kconfig. > > > > LTO with MODVERSIONS will fail in generating correct CRC because > > the makefile rule doesn't work for make with version 3.8X.[1] > > > > Thus we need to check make version during selecting on LTO Kconfig. > > Add CONFIG_MAKE_VERSION which means MAKE_VERSION in canonical digits > > for arithmetic comparisons. > > > > [1] https://lore.kernel.org/lkml/20210616080252.32046-1-lecopzer.chen@xxxxxxxxxxxx/ > > Signed-off-by: Lecopzer Chen <lecopzer.chen@xxxxxxxxxxxx> > > --- > > > NACK. > > "Let's add MAKE_VERSION >= 40200 restriction > just because I cannot write correct code that > works for older Make" is a horrible idea. > > Also, Kconfig is supposed to check the compiler > (or toolchains) capability, not host tool versions. I feel like requiring a Make that's half a decade old for a feature that also requires a toolchain released last October ago isn't entirely unreasonable. That being said, if Masahiro prefers not to rely on the wildcard function's behavior here, which is a reasonable request, we could simply use the shell to test for the file's existence: diff --git a/scripts/Makefile.build b/scripts/Makefile.build index 34d257653fb4..c6bd62f518ff 100644 --- a/scripts/Makefile.build +++ b/scripts/Makefile.build @@ -388,7 +388,7 @@ ifeq ($(CONFIG_LTO_CLANG) $(CONFIG_MODVERSIONS),y y) cmd_update_lto_symversions = \ rm -f $@.symversions \ $(foreach n, $(filter-out FORCE,$^), \ - $(if $(wildcard $(n).symversions), \ + $(if $(shell test -s $(n).symversions && echo y), \ ; cat $(n).symversions >> $@.symversions)) else cmd_update_lto_symversions = echo >/dev/null This is not quite as efficient as using wildcard, but should work with older Make versions too. Thoughts? Sami
