Re: [RFC 01/19] kbuild: Fixes to rules for host-cshlib and host-cxxshlib

Knut Omang
2019-08-14T05:54:02Z

On Wed, 2019-08-14 at 11:02 +0900, Masahiro Yamada wrote:
> Hi Knut,
>
> On Wed, Aug 14, 2019 at 1:19 AM Knut Omang <knut.omang@oracle.com> wrote:
> > On Tue, 2019-08-13 at 23:01 +0900, Masahiro Yamada wrote:
> > > On Tue, Aug 13, 2019 at 3:13 PM Knut Omang <knut.omang@oracle.com> wrote:
> > > > C++ libraries interfacing to C APIs might sometimes need some glue
> > > > logic more easily written in C.
> > > > Allow a C++ library to also contain 0 or more C objects.
> > > >
> > > > Also fix rules for both C and C++ shared libraries:
> > > > - C++ shared libraries depended on .c instead of .cc files
> > > > - Rules were referenced as -objs instead of the intended
> > > > -cobjs and -cxxobjs following the pattern from hostprogs*.
> > > >
> > > > Signed-off-by: Knut Omang <knut.omang@oracle.com>
> > >
> > > How is this patch related to the rest of this series?
> >
> > This is just my (likely naive) way I to get what I had working
> > using autotools in the Github version of KTF) translated into something
> > comparable using kbuild only. We need to build a shared library consisting
> > of a few C++ files and a very simple C file, and a couple of simple binaries,
> > and the rule in there does seem to take .c files and subject them to the
> > C++ compiler, which makes this difficult to achieve?
>
> Looking at the diff stat of the cover-letter,
> the rest of this patch series is touching only
> Documentation/ and tools/testing/kselftests/.
>
> So, this one is unused by the rest of the changes, isn't it?
> Am I missing something?
>
>
>
> > > This patch breaks GCC-plugins.
> > > Did you really compile-test this patch before the submission?
> >
> > Sorry for my ignorance here:
> > I ran through the kernel build and installed the resulting kernel
> > on a VM that I used to test this, if that's what you are asking
> > about?
> >
> > Do I need some unusual .config options or run a special make target
> > to trigger the problem you see?
> >
> > I used a recent Fedora config with default values for new options,
> > and ran the normal default make target (also with O=) and make selftests
> > to test the patch itself.
>
> I just built allmodconfig for arm.
>
> (The 0-day bot tests allmodconfig for most of architectures,
> so you may receive error reports anyway.)
>
>
> With your patch, I got the following:
>
>
> masahiro@grover:~/ref/linux$ make ARCH=arm
> CROSS_COMPILE=arm-linux-gnueabihf- allmodconfig all
> HOSTCC scripts/basic/fixdep
> HOSTCC scripts/kconfig/conf.o
> HOSTCC scripts/kconfig/confdata.o
> HOSTCC scripts/kconfig/expr.o
> LEX scripts/kconfig/lexer.lex.c
> YACC scripts/kconfig/parser.tab.h
> HOSTCC scripts/kconfig/lexer.lex.o
> YACC scripts/kconfig/parser.tab.c
> HOSTCC scripts/kconfig/parser.tab.o
> HOSTCC scripts/kconfig/preprocess.o
> HOSTCC scripts/kconfig/symbol.o
> HOSTLD scripts/kconfig/conf
> scripts/kconfig/conf --allmodconfig Kconfig
> #
> # configuration written to .config
> #
> SYSHDR arch/arm/include/generated/uapi/asm/unistd-common.h
> SYSHDR arch/arm/include/generated/uapi/asm/unistd-oabi.h
> SYSHDR arch/arm/include/generated/uapi/asm/unistd-eabi.h
> HOSTCC scripts/dtc/dtc.o
> HOSTCC scripts/dtc/flattree.o
> HOSTCC scripts/dtc/fstree.o
> HOSTCC scripts/dtc/data.o
> HOSTCC scripts/dtc/livetree.o
> HOSTCC scripts/dtc/treesource.o
> HOSTCC scripts/dtc/srcpos.o
> HOSTCC scripts/dtc/checks.o
> HOSTCC scripts/dtc/util.o
> LEX scripts/dtc/dtc-lexer.lex.c
> YACC scripts/dtc/dtc-parser.tab.h
> HOSTCC scripts/dtc/dtc-lexer.lex.o
> YACC scripts/dtc/dtc-parser.tab.c
> HOSTCC scripts/dtc/dtc-parser.tab.o
> HOSTCC scripts/dtc/yamltree.o
> HOSTLD scripts/dtc/dtc
> CC scripts/gcc-plugins/latent_entropy_plugin.o
> cc1: error: cannot load plugin ./scripts/gcc-plugins/arm_ssp_per_task_plugin.so
> ./scripts/gcc-plugins/arm_ssp_per_task_plugin.so: cannot open
> shared object file: No such file or directory
> cc1: error: cannot load plugin ./scripts/gcc-plugins/structleak_plugin.so
> ./scripts/gcc-plugins/structleak_plugin.so: cannot open shared
> object file: No such file or directory
> cc1: error: cannot load plugin ./scripts/gcc-plugins/latent_entropy_plugin.so
> ./scripts/gcc-plugins/latent_entropy_plugin.so: cannot open shared
> object file: No such file or directory
> cc1: error: cannot load plugin ./scripts/gcc-plugins/randomize_layout_plugin.so
> ./scripts/gcc-plugins/randomize_layout_plugin.so: cannot open
> shared object file: No such file or directory
> make[3]: *** [scripts/Makefile.build;281:
> scripts/gcc-plugins/latent_entropy_plugin.o] Error 1
> make[2]: *** [scripts/Makefile.build;497: scripts/gcc-plugins] Error 2
> make[1]: *** [Makefile;1097: scripts] Error 2
> make: *** [Makefile;330: __build_one_by_one] Error 2

Ok, I see!

I'll recall this target and look into it!

Thanks!
Knut

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