[libcxx-commits] [libcxx] [libc++] Remove trailing newline from _LIBCPP_ASSERTION_HANDLER calls (PR #143573)

[Daniel Thornburgh via libcxx-commits]

mysterymath wrote:

This is causing build failures in the Fuchsia toolchain builders across all platforms. Accordingly, I'm issuing a revert.

Example:
https://luci-milo.appspot.com/ui/p/fuchsia/builders/toolchain.ci/clang-linux-x64/b8711781438372007649/overview

```
[2466/2505](36) Building CXX object libcxx/src/CMakeFiles/cxx_static.dir/verbose_abort.cpp.obj
FAILED: libcxx/src/CMakeFiles/cxx_static.dir/verbose_abort.cpp.obj 
/b/s/w/ir/x/w/llvm_build/./bin/clang++ --target=armv6m-none-eabi -DLIBC_NAMESPACE=__llvm_libc_common_utils -D_DEBUG -D_FILE_OFFSET_BITS=64 -D_GLIBCXX_ASSERTIONS -D_LARGEFILE_SOURCE -D_LIBCPP_BUILDING_HAS_NO_ABI_LIBRARY -D_LIBCPP_BUILDING_LIBRARY -D_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER -D_LIBCPP_LINK_PTHREAD_LIB -D_LIBCPP_LINK_RT_LIB -D_LIBCPP_REMOVE_TRANSITIVE_INCLUDES -D__STDC_CONSTANT_MACROS -D__STDC_FORMAT_MACROS -D__STDC_LIMIT_MACROS -I/b/s/w/ir/x/w/llvm-llvm-project/libcxx/src -I/b/s/w/ir/x/w/llvm_build/include/armv6m-unknown-none-eabi/c++/v1 -I/b/s/w/ir/x/w/llvm_build/include/c++/v1 -I/b/s/w/ir/x/w/llvm-llvm-project/cmake/Modules/../../libc -isystem /b/s/w/ir/x/w/llvm_build/include/armv6m-unknown-none-eabi --target=armv6m-none-eabi -Wno-atomic-alignment "-Dvfprintf(stream, format, vlist)=vprintf(format, vlist)" "-Dfprintf(stream, format, ...)=printf(format)" -D_LIBCPP_PRINT=1 -mthumb -fPIC -fno-semantic-interposition -fvisibility-inlines-hidden -Werror=date-time -Werror=unguarded-availability-new -Wall -Wextra -Wno-unused-parameter -Wwrite-strings -Wcast-qual -Wmissing-field-initializers -Wimplicit-fallthrough -Wcovered-switch-default -Wno-noexcept-type -Wnon-virtual-dtor -Wdelete-non-virtual-dtor -Wsuggest-override -Wstring-conversion -Wmisleading-indentation -Wctad-maybe-unsupported -ffunction-sections -fdata-sections -ffile-prefix-map=/b/s/w/ir/x/w/llvm_build/runtimes/runtimes-armv6m-none-eabi-bins=../../../llvm-llvm-project -ffile-prefix-map=/b/s/w/ir/x/w/llvm-llvm-project/= -no-canonical-prefixes -Os -DNDEBUG -std=c++2b -UNDEBUG -faligned-allocation -nostdinc++ -fvisibility-inlines-hidden -fvisibility=hidden -fsized-deallocation -Wall -Wextra -Wnewline-eof -Wshadow -Wwrite-strings -Wno-unused-parameter -Wno-long-long -Werror=return-type -Wextra-semi -Wundef -Wunused-template -Wformat-nonliteral -Wzero-length-array -Wdeprecated-redundant-constexpr-static-def -Wno-nullability-completeness -Wno-user-defined-literals -Wno-covered-switch-default -Wno-suggest-override -Wno-error -fno-exceptions -fno-rtti -fdebug-prefix-map=/b/s/w/ir/x/w/llvm_build/include/c++/v1=/b/s/w/ir/x/w/llvm-llvm-project/libcxx/include -nostdlibinc -MD -MT libcxx/src/CMakeFiles/cxx_static.dir/verbose_abort.cpp.obj -MF libcxx/src/CMakeFiles/cxx_static.dir/verbose_abort.cpp.obj.d -o libcxx/src/CMakeFiles/cxx_static.dir/verbose_abort.cpp.obj -c /b/s/w/ir/x/w/llvm-llvm-project/libcxx/src/verbose_abort.cpp
/b/s/w/ir/x/w/llvm-llvm-project/libcxx/src/verbose_abort.cpp:35:10: error: reference to unresolved using declaration
   35 |     std::fputc('\n', stderr);
      |          ^
/b/s/w/ir/x/w/llvm_build/include/c++/v1/cstdio:139:1: note: using declaration annotated with 'using_if_exists' here
  139 | using ::fputc _LIBCPP_USING_IF_EXISTS;
      | ^
/b/s/w/ir/x/w/llvm-llvm-project/libcxx/src/verbose_abort.cpp:35:5: error: excess elements in scalar initializer
   35 |     std::fputc('\n', stderr);
      |     ^              ~~~~~
```

https://github.com/llvm/llvm-project/pull/143573