Messages in this thread | | | Date | Sun, 19 Apr 2020 08:37:03 -0700 | From | Nathan Chancellor <> | Subject | Re: [PATCH] kbuild: Set CLANG_VERSION only when Clang is used |
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On Sun, Apr 19, 2020 at 02:36:12PM +0200, Sedat Dilek wrote: > Do like GCC_VERSION is set when GCC (see CC_IS_GCC) is used. > > Signed-off-by: Sedat Dilek <sedat.dilek@gmail.com> > --- > init/Kconfig | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/init/Kconfig b/init/Kconfig > index 9e22ee8fbd75..c23f9d3d6d6c 100644 > --- a/init/Kconfig > +++ b/init/Kconfig > @@ -25,7 +25,7 @@ config CC_IS_CLANG > > config CLANG_VERSION > int > - default $(shell,$(srctree)/scripts/clang-version.sh $(CC)) > + default $(shell,$(srctree)/scripts/clang-version.sh $(CC)) if CC_IS_CLANG > > config CC_CAN_LINK > def_bool $(success,$(srctree)/scripts/cc-can-link.sh $(CC)) > -- > 2.26.1 >
I don't understand the motivation behind this. The commit message needs to be expanded upon or further clarification is needed.
CONFIG_GCC_VERSION is always set, either to 0 if using clang or the actual version spit out by GCC so the commit message is not entirely accurate.
It is done in the
default $(shell,$(srctree)/scripts/gcc-version.sh $(CC)) if CC_IS_GCC default 0
way because it relies on the __GNUC__, __GNUC_MINOR__, and __GNUC_PATCHLEVEL__ preprocessor macros to figure out the verison, which clang also defines (to 4, 2, and 1 respectively) so it has to be done this way to avoid confusing clang for GCC.
We can handle this in clang-version.sh so that CONFIG_CLANG_VERSION is set to zero if CONFIG_CC_IS_GCC is set, just like CONFIG_GCC_VERSION:
if ! ( $compiler --version | grep -q clang) ; then echo 0 exit 1 fi
CONFIG_CLANG_VERSION needs to be defined, otherwise we are breaking the assumption that I made in commit df3da04880b4 ("mips: Fix unroll macro when building with Clang").
With your patch and GCC 9.3.0 building malta_defconfig:
arch/mips/include/asm/r4kcache.h: In function 'blast_scache64_node': arch/mips/include/asm/unroll.h:29:9: error: 'CONFIG_CLANG_VERSION' undeclared (first use in this function); did you mean 'CONFIG_LD_VERSION'? 29 | CONFIG_CLANG_VERSION >= 80000) && \ | ^~~~~~~~~~~~~~~~~~~~ /home/nathan/src/linux/include/linux/compiler.h:330:9: note: in definition of macro '__compiletime_assert' 330 | if (!(condition)) \ | ^~~~~~~~~ /home/nathan/src/linux/include/linux/compiler.h:350:2: note: in expansion of macro '_compiletime_assert' 350 | _compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__) | ^~~~~~~~~~~~~~~~~~~ /home/nathan/src/linux/include/linux/build_bug.h:39:37: note: in expansion of macro 'compiletime_assert' 39 | #define BUILD_BUG_ON_MSG(cond, msg) compiletime_assert(!(cond), msg) | ^~~~~~~~~~~~~~~~~~ /home/nathan/src/linux/include/linux/build_bug.h:50:2: note: in expansion of macro 'BUILD_BUG_ON_MSG' 50 | BUILD_BUG_ON_MSG(condition, "BUILD_BUG_ON failed: " #condition) | ^~~~~~~~~~~~~~~~ /home/nathan/src/linux/arch/mips/include/asm/unroll.h:28:2: note: in expansion of macro 'BUILD_BUG_ON' 28 | BUILD_BUG_ON((CONFIG_GCC_VERSION >= 40700 || \ | ^~~~~~~~~~~~ /home/nathan/src/linux/arch/mips/include/asm/r4kcache.h:203:2: note: in expansion of macro 'unroll' 203 | unroll(times, _cache_op, insn, op, (addr) + (i++ * (lsize))); \ | ^~~~~~ /home/nathan/src/linux/arch/mips/include/asm/r4kcache.h:370:4: note: in expansion of macro 'cache_unroll' 370 | cache_unroll(32, kernel_cache, indexop, \ | ^~~~~~~~~~~~ /home/nathan/src/linux/arch/mips/include/asm/r4kcache.h:376:1: note: in expansion of macro '__BUILD_BLAST_CACHE_NODE' 376 | __BUILD_BLAST_CACHE_NODE(s, scache, Index_Writeback_Inv_SD, Hit_Writeback_Inv_SD, 64) | ^~~~~~~~~~~~~~~~~~~~~~~~
Cheers, Nathan
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