Re: [PATCH v1 04/13] perf build: Error if no libelf and NO_LIBELF isn't set

[Ian Rogers]

On Mon, Mar 13, 2023 at 12:45 PM Arnaldo Carvalho de Melo
<acme@xxxxxxxxxx> wrote:
>
> Em Fri, Mar 10, 2023 at 10:57:44PM -0800, Ian Rogers escreveu:
> > Building without libelf support is going disable a lot of
> > functionality. Require that the NO_LIBELF=1 build option is passed if
> > this is intentional.
>
>
> 'make -C tools/perf build-test' is failing:
>
> ⬢[acme@toolbox perf-tools-next]$ git log --oneline -1 ; time make -C tools/perf build-test
> ace4d44d094ce850 (HEAD -> perf-tools-next) perf build: Remove redundant NO_NEWT build option
> make: Entering directory '/var/home/acme/git/perf-tools-next/tools/perf'
> Warning: Kernel ABI header at 'tools/include/uapi/linux/in.h' differs from latest version at 'include/uapi/linux/in.h'
> Warning: Kernel ABI header at 'tools/arch/x86/include/asm/cpufeatures.h' differs from latest version at 'arch/x86/include/asm/cpufeatures.h'
> Warning: Kernel ABI header at 'tools/arch/arm64/include/uapi/asm/perf_regs.h' differs from latest version at 'arch/arm64/include/uapi/asm/perf_regs.h'
> Warning: Kernel ABI header at 'tools/include/linux/coresight-pmu.h' differs from latest version at 'include/linux/coresight-pmu.h'
> - tarpkg: ./tests/perf-targz-src-pkg .
>                  make_static: cd . && make LDFLAGS=-static NO_PERF_READ_VDSO32=1 NO_PERF_READ_VDSOX32=1 NO_JVMTI=1 -j32  DESTDIR=/tmp/tmp.jqGYXdF9cQ
> cd . && make LDFLAGS=-static NO_PERF_READ_VDSO32=1 NO_PERF_READ_VDSOX32=1 NO_JVMTI=1 -j32 DESTDIR=/tmp/tmp.jqGYXdF9cQ
>   BUILD:   Doing 'make -j32' parallel build
>   HOSTCC  fixdep.o
>   HOSTLD  fixdep-in.o
>   LINK    fixdep
> Warning: Kernel ABI header at 'tools/include/uapi/linux/in.h' differs from latest version at 'include/uapi/linux/in.h'
> diff -u tools/include/uapi/linux/in.h include/uapi/linux/in.h
> Warning: Kernel ABI header at 'tools/arch/x86/include/asm/cpufeatures.h' differs from latest version at 'arch/x86/include/asm/cpufeatures.h'
> diff -u tools/arch/x86/include/asm/cpufeatures.h arch/x86/include/asm/cpufeatures.h
> Warning: Kernel ABI header at 'tools/arch/arm64/include/uapi/asm/perf_regs.h' differs from latest version at 'arch/arm64/include/uapi/asm/perf_regs.h'
> diff -u tools/arch/arm64/include/uapi/asm/perf_regs.h arch/arm64/include/uapi/asm/perf_regs.h
> Warning: Kernel ABI header at 'tools/include/linux/coresight-pmu.h' differs from latest version at 'include/linux/coresight-pmu.h'
> diff -u tools/include/linux/coresight-pmu.h include/linux/coresight-pmu.h
> Makefile.config:429: *** ERROR: No libelf found. Disables 'probe' tool, jvmti and BPF support. Please install libelf-dev, libelf-devel, elfutils-libelf-devel or build with NO_LIBELF=1..  Stop.
> make[3]: *** [Makefile.perf:236: sub-make] Error 2
> make[2]: *** [Makefile:70: all] Error 2
>   test: test -x ./perf
> make[1]: *** [tests/make:316: make_static] Error 1
> make: *** [Makefile:103: build-test] Error 2
>
> Same thing for the libtraceevent, I'll add NO_LIBTRACEEVENT=1 and NO_LIBELF=1 to the static build test in tools/perf/tests/make

Right, this is kind of the point of the patch set. Make it harder for
people to make a reduced perf binary without explicitly flagging that
this is what they want. For the build tests it may be better to make
the flag conditional on what is installed in the image.

Thanks,
Ian