[all-commits] [llvm/llvm-project] c000f7: [libc++][test] Avoid non-Standard zero-length arra...

[Stephan T. Lavavej via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: c000f754bfb9fb3a7a0a1f9b0485f36ae70534b7
      https://github.com/llvm/llvm-project/commit/c000f754bfb9fb3a7a0a1f9b0485f36ae70534b7
  Author: Stephan T. Lavavej <stl at nuwen.net>
  Date:   2023-12-03 (Sun, 03 Dec 2023)

  Changed paths:
    M libcxx/test/libcxx/gdb/gdb_pretty_printer_test.py
    M libcxx/test/std/algorithms/alg.modifying.operations/alg.random.shuffle/random_shuffle.pass.cpp
    M libcxx/test/std/algorithms/alg.modifying.operations/alg.transform/ranges.transform.binary.iterator.pass.cpp
    M libcxx/test/std/algorithms/alg.modifying.operations/alg.transform/ranges.transform.binary.range.pass.cpp
    M libcxx/test/std/algorithms/alg.modifying.operations/alg.transform/ranges.transform.unary.pass.cpp
    M libcxx/test/std/algorithms/alg.nonmodifying/alg.ends_with/ranges.ends_with.pass.cpp
    M libcxx/test/std/algorithms/alg.nonmodifying/alg.equal/ranges.equal.pass.cpp
    M libcxx/test/std/algorithms/alg.nonmodifying/alg.find.end/ranges.find_end.pass.cpp
    M libcxx/test/std/algorithms/alg.nonmodifying/alg.foreach/ranges.for_each.pass.cpp
    M libcxx/test/std/algorithms/alg.nonmodifying/alg.foreach/ranges.for_each_n.pass.cpp
    M libcxx/test/std/algorithms/alg.nonmodifying/alg.search/ranges.search.pass.cpp
    M libcxx/test/std/algorithms/alg.nonmodifying/alg.search/ranges.search_n.pass.cpp
    M libcxx/test/std/algorithms/alg.nonmodifying/alg.starts_with/ranges.starts_with.pass.cpp
    M libcxx/test/std/algorithms/alg.sorting/alg.partitions/ranges.is_partitioned.pass.cpp
    M libcxx/test/std/algorithms/alg.sorting/alg.sort/is.sorted/ranges.is_sorted.pass.cpp
    M libcxx/test/std/algorithms/alg.sorting/alg.sort/is.sorted/ranges.is_sorted_until.pass.cpp
    M libcxx/test/std/utilities/smartptr/unique.ptr/unique.ptr.class/unique.ptr.observers/op_subscript.runtime.pass.cpp
    M libcxx/utils/libcxx/test/params.py

  Log Message:
  -----------
  [libc++][test] Avoid non-Standard zero-length arrays (#74183)

Found while running libc++'s test suite with MSVC's STL, where we use
both MSVC's compiler and Clang/LLVM.

MSVC's compiler rejects the non-Standard extension of zero-length
arrays. For conformance, I'm changing these occurrences to
`std::array<int, 0>`.

Many of these files already had `#include <array>`; I'm adding it to the
rest.

I wanted to add `-Wzero-length-array` to
`libcxx/utils/libcxx/test/params.py` to prevent future occurrences, but
it complained about product code :crying_cat_face: :

```
In file included from /home/runner/_work/llvm-project/llvm-project/libcxx/test/std/input.output/iostream.format/input.streams/istream.formatted/istream.formatted.arithmetic/long.pass.cpp:18:
In file included from /home/runner/_work/llvm-project/llvm-project/build/generic-cxx03/include/c++/v1/istream:170:
In file included from /home/runner/_work/llvm-project/llvm-project/build/generic-cxx03/include/c++/v1/ostream:172:
In file included from /home/runner/_work/llvm-project/llvm-project/build/generic-cxx03/include/c++/v1/__system_error/error_code.h:18:
In file included from /home/runner/_work/llvm-project/llvm-project/build/generic-cxx03/include/c++/v1/__system_error/error_category.h:15:
/home/runner/_work/llvm-project/llvm-project/build/generic-cxx03/include/c++/v1/string:811:25: error: zero size arrays are an extension [-Werror,-Wzero-length-array]
  811 |         char __padding_[sizeof(value_type) - 1];
      |                         ^~~~~~~~~~~~~~~~~~~~~~
/home/runner/_work/llvm-project/llvm-project/build/generic-cxx03/include/c++/v1/string:817:19: note: in instantiation of member class 'std::basic_string<char>::__short' requested here
  817 |     static_assert(sizeof(__short) == (sizeof(value_type) * (__min_cap + 1)), "__short has an unexpected size.");
      |                   ^
/home/runner/_work/llvm-project/llvm-project/build/generic-cxx03/include/c++/v1/string:2069:5: note: in instantiation of template class 'std::basic_string<char>' requested here
 2069 |     _LIBCPP_STRING_V1_EXTERN_TEMPLATE_LIST(_LIBCPP_DECLARE, char)
      |     ^
/home/runner/_work/llvm-project/llvm-project/build/generic-cxx03/include/c++/v1/__string/extern_template_lists.h:31:60: note: expanded from macro '_LIBCPP_STRING_V1_EXTERN_TEMPLATE_LIST'
   31 |   _Func(_LIBCPP_EXPORTED_FROM_ABI basic_string<_CharType>& basic_string<_CharType>::replace(size_type, size_type, value_type const*, size_type)) \
      |                                                            ^
```

I pushed a tiny commit to fix unrelated comment typos, in an attempt to
clear out spurious CI failures.