Re: r344798: c++: error: linker command failed with exit code

On 5 Mar 2019, at 21:54, O. Hartmann <ohartmann_at_walstatt.org> wrote:
> 
> Am Tue, 5 Mar 2019 13:16:26 -0500
> Shawn Webb <shawn.webb_at_hardenedbsd.org> schrieb:
> 
> > On Tue, Mar 05, 2019 at 05:45:11PM +0100, O. Hartmann wrote:
> > > -----BEGIN PGP SIGNED MESSAGE-----
> > > Hash: SHA256
> > >
> > > Hello,
> > >
> > > recent buildworld on a CURRENT box (FreeBSD 13.0-CURRENT #246 r344742: Sun Mar  3 21:26:44
> > > CET 2019 amd64) fails to build due to:
> > >
> > > [...]
> > >
> > > Building /usr/obj/usr/src/amd64.amd64/tmp/obj-tools/usr.bin/clang/clang/clang
> > > - --- clang ---
> > > ld: error: undefined symbol: llvm::createBPFMIPreEmitCheckingPass()
> > > >>> referenced by BPFTargetMachine.cpp
> > > >>>               BPFTargetMachine.o:((anonymous
> > > >>> namespace)::BPFPassConfig::addPreEmitPass()) in
> > > >>> archive /usr/obj/usr/src/amd64.amd64/tmp/obj-tools/lib/clang/libllvm/libllvm.a
> > > ld: error: undefined symbol: llvm::BTFDebug::BTFDebug(llvm::AsmPrinter*)
> > > >>> referenced by BPFAsmPrinter.cpp
> > > >>>               BPFAsmPrinter.o:((anonymous
> > > >>> namespace)::BPFAsmPrinter::doInitialization(llvm::Module&)) in
> > > >>> archive /usr/obj/usr/src/amd64.amd64/tmp/obj-tools/lib/clang/libllvm/libllvm.a
> > > c++: error: linker command failed with exit code 1 (use -v to see invocation)
> > > *** [clang] Error code 1
> > >
> > > make[4]: stopped in /usr/src/usr.bin/clang/clang
> > > [...]
> > >
> > > I tried to rebuild world from a fresh /usr/src and /usr/obj but the host gets always stuck
> > > at the same error.
> >
> > Do you have a custom src.conf and make.conf?
> >
> > Thanks,
> >
> src.conf, yes, make.conf, yes, but make.conf references only ports tree stuff so far. src.conf:
> 
> #
> CPUTYPE?=           native
> #
> #CFLAGS+=            -O3
> # for the kernel
> #COPTFLAGS+=         -O3
> #
> #CXXFLAGS+=         -std=c++11
> #
> WITH_CLANG_EXTRAS=      YES
> WITH_LLDB=              YES
> WITH_LLD_IS_LD=         YES
> #
> WITH_IDEA=              YES
> #
> #WITH_BSD_GREP=         YES
> #
> WITH_OFED_EXTRA=        YES
> WITH_NAND=              YES
> #WITH_CTF=              YES
> #
> WITH_SVN=               YES
> #
> # Enable building openldap support for kerberos.
> #WITH_OPENLDAP=         YES
> #
> WITH_SORT_THREADS=      YES
> #
> WITH_EXTRA_TCP_STACKS=  YES
> #
> WITH_ZONEINFO_LEAPSECONDS_SUPPORT=  YES
> #
> MALLOC_PRODUCTION=      YES
> #
> WITHOUT_ASSERT_DEBUG=   YES
> #
> WITHOUT_TESTS=          YES
> #
> WITHOUT_DEBUG_FILES=    YES
> #
> WITHOUT_REPRODUCIBLE_BUILD= YES
> #
> #  mitigation for CVE-2017-5715 in the kernel build
> #WITH_KERNEL_RETPOLINE= YES

Your original error messages seemed to indicate that you were building
with MK_LLVM_TARGET_BPF=yes (which is not enabled by default).  I don't
see it in your src.conf, but maybe you enabled it in some other way?

In any case, I have committed a fix in r344825.

-Dimitry