[libc-commits] [libc] [libc] Support configurable errno modes (PR #98287)

[LLVM Continuous Integration via libc-commits]

llvm-ci wrote:

LLVM Buildbot has detected a new failure on builder `libc-aarch64-ubuntu-dbg` running on `libc-aarch64-ubuntu` while building `libc` at step 4 "annotate".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/104/builds/2085

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 -- failed to compile
-- Configuring done
-- Generating done
-- Build files have been written to: /home/libc-buildbot/libc-aarch64-ubuntu/libc-aarch64-ubuntu/build
@@@BUILD_STEP build libc@@@
Running: ninja libc
[1/390] Building CXX object projects/libc/src/errno/CMakeFiles/libc.src.errno.errno.dir/libc_errno.cpp.o
FAILED: projects/libc/src/errno/CMakeFiles/libc.src.errno.errno.dir/libc_errno.cpp.o 
/usr/bin/clang++ -DLIBC_NAMESPACE=__llvm_libc_18_0_0_git -D_DEBUG -Iprojects/libc/src/errno -I/home/libc-buildbot/libc-aarch64-ubuntu/libc-aarch64-ubuntu/llvm-project/libc/src/errno -I/home/libc-buildbot/libc-aarch64-ubuntu/libc-aarch64-ubuntu/llvm-project/libc -isystem projects/libc/include -fPIC -fvisibility-inlines-hidden -Werror=date-time -Werror=unguarded-availability-new -Wall -Wextra -Wno-unused-parameter -Wwrite-strings -Wcast-qual -Wmissing-field-initializers -pedantic -Wno-long-long -Wc++98-compat-extra-semi -Wimplicit-fallthrough -Wcovered-switch-default -Wno-noexcept-type -Wnon-virtual-dtor -Wdelete-non-virtual-dtor -Wsuggest-override -Wstring-conversion -Wmisleading-indentation -Wctad-maybe-unsupported -fdiagnostics-color -g -fpie -fno-builtin -fno-exceptions -fno-lax-vector-conversions -fno-unwind-tables -fno-asynchronous-unwind-tables -fno-rtti -ftrivial-auto-var-init=pattern -fno-omit-frame-pointer -Wall -Wextra -Werror -Wconversion -Wno-sign-conversion -Wimplicit-fallthrough -Wwrite-strings -Wextra-semi -Wnewline-eof -Wnonportable-system-include-path -Wstrict-prototypes -Wthread-safety -Wglobal-constructors -DLIBC_COPT_PUBLIC_PACKAGING -std=c++17 -MD -MT projects/libc/src/errno/CMakeFiles/libc.src.errno.errno.dir/libc_errno.cpp.o -MF projects/libc/src/errno/CMakeFiles/libc.src.errno.errno.dir/libc_errno.cpp.o.d -o projects/libc/src/errno/CMakeFiles/libc.src.errno.errno.dir/libc_errno.cpp.o -c /home/libc-buildbot/libc-aarch64-ubuntu/libc-aarch64-ubuntu/llvm-project/libc/src/errno/libc_errno.cpp
/home/libc-buildbot/libc-aarch64-ubuntu/libc-aarch64-ubuntu/llvm-project/libc/src/errno/libc_errno.cpp:91:32: error: use of undeclared identifier 'errno'
void Errno::operator=(int a) { errno = a; }
                               ^
/home/libc-buildbot/libc-aarch64-ubuntu/libc-aarch64-ubuntu/llvm-project/libc/src/errno/libc_errno.cpp:92:32: error: use of undeclared identifier 'errno'
Errno::operator int() { return errno; }
                               ^
2 errors generated.
[2/390] Building CXX object projects/libc/src/__support/OSUtil/linux/CMakeFiles/libc.src.__support.OSUtil.linux.linux_util.dir/fcntl.cpp.o
[3/390] Building CXX object projects/libc/src/__support/File/linux/CMakeFiles/libc.src.__support.File.linux.file.dir/file.cpp.o
[4/390] Building CXX object projects/libc/src/__support/File/CMakeFiles/libc.src.__support.File.file.dir/file.cpp.o
[5/390] Building CXX object projects/libc/src/fenv/CMakeFiles/libc.src.fenv.fesetround.dir/fesetround.cpp.o
[6/390] Building CXX object projects/libc/src/fenv/CMakeFiles/libc.src.fenv.fesetexceptflag.dir/fesetexceptflag.cpp.o
[7/390] Building CXX object projects/libc/src/fenv/CMakeFiles/libc.src.fenv.fegetround.dir/fegetround.cpp.o
[8/390] Building CXX object projects/libc/src/fenv/CMakeFiles/libc.src.fenv.fetestexceptflag.dir/fetestexceptflag.cpp.o
[9/390] Building CXX object projects/libc/src/fenv/CMakeFiles/libc.src.fenv.fesetenv.dir/fesetenv.cpp.o
[10/390] Building CXX object projects/libc/src/fenv/CMakeFiles/libc.src.fenv.fegetenv.dir/fegetenv.cpp.o
[11/390] Building CXX object projects/libc/src/fenv/CMakeFiles/libc.src.fenv.fedisableexcept.dir/fedisableexcept.cpp.o
[12/390] Building CXX object projects/libc/src/fenv/CMakeFiles/libc.src.fenv.feclearexcept.dir/feclearexcept.cpp.o
[13/390] Building CXX object projects/libc/src/fenv/CMakeFiles/libc.src.fenv.fesetexcept.dir/fesetexcept.cpp.o
[14/390] Building CXX object projects/libc/src/fenv/CMakeFiles/libc.src.fenv.feupdateenv.dir/feupdateenv.cpp.o
[15/390] Building CXX object projects/libc/src/fenv/CMakeFiles/libc.src.fenv.feholdexcept.dir/feholdexcept.cpp.o
[16/390] Building CXX object projects/libc/src/fenv/CMakeFiles/libc.src.fenv.fetestexcept.dir/fetestexcept.cpp.o
[17/390] Building CXX object projects/libc/src/fenv/CMakeFiles/libc.src.fenv.fegetexceptflag.dir/fegetexceptflag.cpp.o
[18/390] Building CXX object projects/libc/src/fenv/CMakeFiles/libc.src.fenv.feraiseexcept.dir/feraiseexcept.cpp.o
ninja: build stopped: subcommand failed.
['ninja', 'libc'] exited with return code 1.
The build step threw an exception...
Traceback (most recent call last):
  File "../llvm-zorg/zorg/buildbot/builders/annotated/libc-linux.py", line 164, in step
    yield
  File "../llvm-zorg/zorg/buildbot/builders/annotated/libc-linux.py", line 121, in main
    run_command(['ninja', 'libc'])
  File "../llvm-zorg/zorg/buildbot/builders/annotated/libc-linux.py", line 179, in run_command
    util.report_run_cmd(cmd, cwd=directory)
  File "/home/libc-buildbot/libc-aarch64-ubuntu/libc-aarch64-ubuntu/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/python2.7/subprocess.py", line 190, in check_call

```

https://github.com/llvm/llvm-project/pull/98287