Bazel uses /usr/bin/clang instead of /usr/bin/clang++ to link C++ code on FreeBSD? #12023
Closed as not planned
Description
Description of the problem / feature request:
Apparently, Bazel uses /usr/bin/clang instead of /usr/bin/clang++ to compile/link C++ code. I'm not sure whether this is intentional, but the behavior for clang is different from clang++ resulting in subtle problems at compile/link time:
❯ /usr/bin/clang -o bazel-out/freebsd-fastbuild/bin/time_zone_lookup_test '-Wl,-rpath,$ORIGIN/_solib_freebsd/' -Lbazel-out/freebsd-fastbuild/bin/_solib_freebsd bazel-out/freebsd-fastbuild/bin/_objs/time_zone_lookup_test/time_zone_lookup_test.pic.o -llibtime_Uzone -llibcivil_Utime -lexternal_Scom_Ugoogle_Ugoogletest_Slibgtest_Umain -lexternal_Scom_Ugoogle_Ugoogletest_Slibgtest -pthread -Wl,-S -lstdc++ -Wl,-z,relro,-z,now -no-canonical-prefixes
ld: error: bazel-out/freebsd-fastbuild/bin/_solib_freebsd/liblibtime_Uzone.so: undefined reference to ceilf
clang: error: linker command failed with exit code 1 (use -v to see invocation)
❯ /usr/bin/clang++ -o bazel-out/freebsd-fastbuild/bin/time_zone_lookup_test '-Wl,-rpath,$ORIGIN/_solib_freebsd/' -Lbazel-out/freebsd-fastbuild/bin/_solib_freebsd bazel-out/freebsd-fastbuild/bin/_objs/time_zone_lookup_test/time_zone_lookup_test.pic.o -llibtime_Uzone -llibcivil_Utime -lexternal_Scom_Ugoogle_Ugoogletest_Slibgtest_Umain -lexternal_Scom_Ugoogle_Ugoogletest_Slibgtest -pthread -Wl,-S -lstdc++ -Wl,-z,relro,-z,now -no-canonical-prefixesThe first command is what Bazel uses for purely C++ code on my FreeBSD system and the latter is what it should use. The only difference is clang++ instead of clang.
Feature requests: what underlying problem are you trying to solve with this feature?
- Perhaps use clang++/g++ for C++ code and clang/gcc for C code.
- The two languages should use different rules as well:
cc_libraryfor C++ andc_libraryfor C code.
Bugs: what's the simplest, easiest way to reproduce this bug? Please provide a minimal example if possible.
❯ git clone https://github.com/google/cctz
...
❯ bazel test ...
...
ERROR: /usr/home/yesudeep/code/yesudeep/cctz/BUILD:165:10: Linking of rule '//:example3' failed (Exit 1) clang failed: error executing command /usr/bin/clang -o bazel-out/freebsd-fastbuild/bin/example3 bazel-out/freebsd-fastbuild/bin/_objs/example3/example3.pic.o bazel-out/freebsd-fastbuild/bin/libtime_zone.a ... (remaining 5 argument(s) skipped)
Use --sandbox_debug to see verbose messages from the sandbox
ld: error: undefined symbol: ceilf
>>> referenced by time_zone_impl.cc
>>> time_zone_impl.pic.o:(ceil(float)) in archive bazel-out/freebsd-fastbuild/bin/libtime_zone.a
clang: error: linker command failed with exit code 1 (use -v to see invocation)
INFO: Elapsed time: 0.357s, Critical Path: 0.03s
INFO: 0 processes.
FAILED: Build did NOT complete successfully
//:cctz_benchmark NO STATUS
//:civil_time_test NO STATUS
//:time_zone_format_test NO STATUS
//:time_zone_lookup_test NO STATUS
FAILED: Build did NOT complete successfullyWhat operating system are you running Bazel on?
- FreeBSD 12.0-RELEASE
❯ uname -a
FreeBSD monalisa 12.1-RELEASE-p2 FreeBSD 12.1-RELEASE-p2 GENERIC amd64
❯ /usr/bin/clang++ --version
FreeBSD clang version 8.0.1 (tags/RELEASE_801/final 366581) (based on LLVM 8.0.1)
Target: x86_64-unknown-freebsd12.1
Thread model: posix
InstalledDir: /usr/binand
- GhostBSD 20.08.20 (FreeBSD 12.0-RELEASE based)
❯ uname -a
FreeBSD mevin 12.1-STABLE FreeBSD 12.1-STABLE GENERIC amd64
❯ /usr/bin/clang++ --version
FreeBSD clang version 10.0.0 (git@github.com:llvm/llvm-project.git llvmorg-10.0.0-0-gd32170dbd5b)
Target: x86_64-unknown-freebsd12.1
Thread model: posix
InstalledDir: /usr/binWhat's the output of bazel info release?
- FreeBSD
❯ bazel --version
bazel 3.3.0and
- GhostBSD (FreeBSD 12.0-RELEASE based)
❯ bazel info release
release 3.4.1What's the output of git remote get-url origin ; git rev-parse master ; git rev-parse HEAD ?
❯ git remote get-url origin; git rev-parse master; git rev-parse HEAD
https://github.com/google/cctz
da5a52d91bf212a1f8c17f366ed8b947e2663d2a
da5a52d91bf212a1f8c17f366ed8b947e2663d2aHave you found anything relevant by searching the web?
Yes, apparently, everybody including me was getting around this by adding -lm linker flags until it was noticed that /usr/bin/clang is being used instead of /usr/bin/clang++ to link C++ code. Here's an example from the Bazel source tree.
Any other information, logs, or outputs that you want to share?
I think the above should include the logs, but please ask if you
need anything else.