Re: problem linking kernel

From: Wojciech Puchar <wojtek_at_puchar.net> wrote on
Date: Sun, 29 Oct 2023 12:16:31 UTC :

> reason found.
> 
> 
> /usr/local/bin/ld which is part of gcc from ports takes precedence

I've run into the FreeBSD system toolchain using a linker
that was below /usr/local/ multiple times before. I try to
avoid building ports that results in the conflict.

But, in my view, the FreeBSD toolchain should require an
explicit command line option to be willing to use part
of a toolchain that is someplace under /usr/local/ instead
of using its own toolchain materials for everything.

See, for example, my report from 2022-Sept:

https://lists.freebsd.org/archives/freebsd-toolchain/2022-September/000898.html

where, in an aarch64 context, it used:

/usr/local/bin/aarch64-unknown-freebsd14.0-ld

instead of:

/sur/bin/ld
or:
/usr/bin/dl.lld

It did not do this if -fuse-ld=lld was explicitly indicated on
the command line: one way to avoid the problem.

What is used can be seen in the extra output from use of:

clang++ -v

Back then the example was:

clang++ -v -std=c++20 -Wpedantic -Wall -Wextra   -I../other_src_used  -pedantic  -g3 -O3 -mcpu=cortex-a72 -flto=thin  -pthread -flto=thin ../objs/cpp_thousandslocale-clang++_14_O3lto-libc++.o  ../objs/cpp_clockinfo-clang++_14_O3lto-libc++.o -o ../cpp_clockinfo_main-HoneyComb-65536MiB-threads_16-LP64-FreeBSD_main_n256584_5bc926af9fd1_64bit-clang++_14_O3lto-libc++  -DCPPCLOCKINFO_VERS='"acpphint_0.1.24"'  ../other_src_used/cpp_clockinfo_main.cpp
FreeBSD clang version 14.0.5 (https://github.com/llvm/llvm-project.git llvmorg-14.0.5-0-gc12386ae247c)
Target: aarch64-unknown-freebsd14.0
Thread model: posix
InstalledDir: /usr/bin
"/usr/bin/clang++" -cc1 -triple aarch64-unknown-freebsd14.0 -emit-llvm-bc -flto=thin -flto-unit -disable-free -clear-ast-before-backend -disable-llvm-verifier -discard-value-names -main-file-name cpp_clockinfo_main.cpp -mrelocation-model static -mframe-pointer=non-leaf -ffp-contract=on -fno-rounding-math -mconstructor-aliases -funwind-tables=2 -target-cpu cortex-a72 -target-feature +v8a -target-feature +fp-armv8 -target-feature +neon -target-feature +crc -target-feature +crypto -target-feature +sha2 -target-feature +aes -target-abi aapcs -fallow-half-arguments-and-returns -mllvm -treat-scalable-fixed-error-as-warning -debug-info-kind=standalone -dwarf-version=4 -debugger-tuning=gdb -v -fcoverage-compilation-dir=/root/acpphint/acpphint_src -resource-dir /usr/lib/clang/14.0.5 -I ../other_src_used -D "CPPCLOCKINFO_VERS=\"acpphint_0.1.24\"" -internal-isystem /usr/include/c++/v1 -O3 -Wpedantic -Wall -Wextra -pedantic -std=c++20 -fdeprecated-macro -fdebug-compilation-dir=/root/acpphint/acpphint_src -ferror-limit 19 -pthread -fno-signed-char -fgnuc-version=4.2.1 -fno-implicit-modules -fcxx-exceptions -fexceptions -fcolor-diagnostics -vectorize-loops -vectorize-slp -faddrsig -D__GCC_HAVE_DWARF2_CFI_ASM=1 -o /tmp/cpp_clockinfo_main-56273f.o -x c++ ../other_src_used/cpp_clockinfo_main.cpp
clang -cc1 version 14.0.5 based upon LLVM 14.0.5 default target aarch64-unknown-freebsd14.0
#include "..." search starts here:
#include <...> search starts here:
../other_src_used
/usr/include/c++/v1
/usr/lib/clang/14.0.5/include
/usr/include
End of search list.
"/usr/local/bin/aarch64-unknown-freebsd14.0-ld" --eh-frame-hdr -dynamic-linker /libexec/ld-elf.so.1 --enable-new-dtags -o ../cpp_clockinfo_main-HoneyComb-65536MiB-threads_16-LP64-FreeBSD_main_n256584_5bc926af9fd1_64bit-clang++_14_O3lto-libc++ /usr/lib/crt1.o /usr/lib/crti.o /usr/lib/crtbegin.o -L/usr/lib -plugin /usr/bin/../lib/LLVMgold.so -plugin-opt=mcpu=cortex-a72 -plugin-opt=O3 -plugin-opt=thinlto ../objs/cpp_thousandslocale-clang++_14_O3lto-libc++.o ../objs/cpp_clockinfo-clang++_14_O3lto-libc++.o /tmp/cpp_clockinfo_main-56273f.o -lc++ -lm -lgcc --as-needed -lgcc_s --no-as-needed -lpthread -lc -lgcc --as-needed -lgcc_s --no-as-needed /usr/lib/crtend.o /usr/lib/crtn.o
/usr/local/bin/aarch64-unknown-freebsd14.0-ld: /usr/bin/../lib/LLVMgold.so: error loading plugin: Cannot open "/usr/bin/../lib/LLVMgold.so"
clang++: error: linker command failed with exit code 1 (use -v to see invocation)
*** Error code 1

Note the: "/usr/local/bin/aarch64-unknown-freebsd14.0-ld" after the search list.

It looks like I did not report my PATH back then. But finding and using
aarch64-unknown-freebsd14.0-ld is not going to be found under any
system path for the system toolchain. So my  view is that the name
should not be looked for by the system toolchain --or should be last
if the normal system names are not found.

FYI:

# echo $PATH
/sbin:/bin:/usr/sbin:/usr/bin:/usr/local/sbin:/usr/local/bin:/usr/home/root/bin

and it is unlikely to have had any changes since back then.

> PATH=/sbin:/bin:/usr/sbin:/usr/bin:/usr/games make
> 
> and all builds
> 
> On Sun, 29 Oct 2023, Dimitry Andric wrote:
> 
> > On 29 Oct 2023, at 11:34, Wojciech Puchar <wojtek@puchar.net> wrote:
> >>
> >> i get this linking my custom kernel. No errors until link
> >>
> >> linking kernel
> >> ld: dynamic STT_GNU_IFUNC symbol `rdtsc_ordered' with pointer equality in `cpu_machdep.o' can not be used when making an executable; recompile with -fPIE and relink with -pie
> >>
> >>
> >> kernel config attached, latest FreeBSD-13 downloaded today.
> >>
> >> can you help?<conf.txt>
> >
> > I just tried it here, and it works fine:
> >
> > ...
> > linking kernel
> > objcopy --strip-debug kernel
> > text data bss dec hex filename
> > 7925073 779012 3411328 12115413 0xb8ddd5 kernel
> > --------------------------------------------------------------
> >>>> Kernel build for PUCHAR completed on Sun Oct 29 12:06:08 UTC 2023
> > --------------------------------------------------------------
> >>>> Kernel(s) PUCHAR built in 28 seconds, ncpu: 32, make -j32
> > --------------------------------------------------------------
> >

===
Mark Millard
marklmi at yahoo.com