[libc-commits] [libc] [libc][startup] set --target= for linker when cross compiling (PR #96342)

[LLVM Continuous Integration via libc-commits]

llvm-ci wrote:

LLVM Buildbot has detected a new failure on builder `libc-x86_64-debian-gcc-fullbuild-dbg` running on `libc-x86_64-debian-fullbuild` while building `libc` at step 4 "annotate".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/131/builds/532

Here is the relevant piece of the build log for the reference:
```
Step 4 (annotate) failure: 'python ../llvm-zorg/zorg/buildbot/builders/annotated/libc-linux.py ...' (failure)
...
-- Performing Test HAVE_GNU_POSIX_REGEX -- failed to compile
-- Performing Test HAVE_POSIX_REGEX -- success
-- Performing Test HAVE_STEADY_CLOCK -- success
-- Performing Test HAVE_PTHREAD_AFFINITY -- success
-- Configuring done
-- Generating done
-- Build files have been written to: /home/llvm-libc-buildbot/buildbot-worker/libc-x86_64-debian-fullbuild/libc-x86_64-debian-gcc-fullbuild-dbg/build
@@@BUILD_STEP build libc@@@
Running: ninja libc
[1/1] Linking CXX executable projects/libc/startup/linux/crt1.o
FAILED: projects/libc/startup/linux/crt1.o 
: && /usr/bin/g++ -fPIC -fno-semantic-interposition -fvisibility-inlines-hidden -Werror=date-time -fno-lifetime-dse -Wall -Wextra -Wno-unused-parameter -Wwrite-strings -Wcast-qual -Wno-missing-field-initializers -pedantic -Wno-long-long -Wimplicit-fallthrough -Wno-maybe-uninitialized -Wno-nonnull -Wno-class-memaccess -Wno-redundant-move -Wno-pessimizing-move -Wno-noexcept-type -Wdelete-non-virtual-dtor -Wsuggest-override -Wno-comment -Wno-misleading-indentation -Wctad-maybe-unsupported -fdiagnostics-color -g -r -nostdlib --target= projects/libc/startup/linux/x86_64/CMakeFiles/libc.startup.linux.x86_64.start.dir/start.cpp.o projects/libc/startup/linux/x86_64/CMakeFiles/libc.startup.linux.x86_64.tls.dir/tls.cpp.o projects/libc/startup/linux/CMakeFiles/libc.startup.linux.do_start.dir/do_start.cpp.o -o projects/libc/startup/linux/crt1.o   && :
g++: error: unrecognized command-line option ‘--target=’; did you mean ‘--target-ar=’?
ninja: build stopped: subcommand failed.
['ninja', 'libc'] exited with return code 1.
The build step threw an exception...
Traceback (most recent call last):
  File "/home/llvm-libc-buildbot/buildbot-worker/libc-x86_64-debian-fullbuild/libc-x86_64-debian-gcc-fullbuild-dbg/build/../llvm-zorg/zorg/buildbot/builders/annotated/libc-linux.py", line 163, in step
    yield
  File "/home/llvm-libc-buildbot/buildbot-worker/libc-x86_64-debian-fullbuild/libc-x86_64-debian-gcc-fullbuild-dbg/build/../llvm-zorg/zorg/buildbot/builders/annotated/libc-linux.py", line 120, in main
    run_command(['ninja', 'libc'])
  File "/home/llvm-libc-buildbot/buildbot-worker/libc-x86_64-debian-fullbuild/libc-x86_64-debian-gcc-fullbuild-dbg/build/../llvm-zorg/zorg/buildbot/builders/annotated/libc-linux.py", line 178, in run_command
    util.report_run_cmd(cmd, cwd=directory)
  File "/home/llvm-libc-buildbot/buildbot-worker/libc-x86_64-debian-fullbuild/libc-x86_64-debian-gcc-fullbuild-dbg/llvm-zorg/zorg/buildbot/builders/annotated/util.py", line 49, in report_run_cmd
    subprocess.check_call(cmd, shell=shell, *args, **kwargs)
  File "/usr/lib/python3.11/subprocess.py", line 413, in check_call
    raise CalledProcessError(retcode, cmd)
subprocess.CalledProcessError: Command '['ninja', 'libc']' returned non-zero exit status 1.
@@@STEP_FAILURE@@@
@@@BUILD_STEP build libc-startup@@@
Running: ninja libc-startup

```

https://github.com/llvm/llvm-project/pull/96342