[C++] ABI break in patch release 15.0.1

[musicinmybrain]

Describe the bug, including details regarding any error messages, version, and platform.

An ABI break was reported between 15.0.0 and 15.0.1 in Fedora Linux (downstream bug).

It looks like 91be098 changed the types of several class method parameters that appear in the public API from const std::string& to std::string_view.

================ changes of 'libarrow.so.1500.0.0'===============
  Functions changes summary: 6 Removed, 0 Changed (11 filtered out), 6 Added functions
  Variables changes summary: 0 Removed, 0 Changed, 0 Added variable

  6 Removed functions:

    [D] 'method bool arrow::KeyValueMetadata::Contains(const std::string&) const'    {_ZNK5arrow16KeyValueMetadata8ContainsERKNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEE}
    [D] 'method arrow::Status arrow::KeyValueMetadata::Delete(const std::string&)'    {_ZN5arrow16KeyValueMetadata6DeleteERKNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEE}
    [D] 'method int arrow::KeyValueMetadata::FindKey(const std::string&) const'    {_ZNK5arrow16KeyValueMetadata7FindKeyERKNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEE}
    [D] 'method arrow::Result<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > > arrow::KeyValueMetadata::Get(const std::string&) const'    {_ZNK5arrow16KeyValueMetadata3GetERKNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEE}
    [D] 'method arrow::Status arrow::KeyValueMetadata::Set(const std::string&, const std::string&)'    {_ZN5arrow16KeyValueMetadata3SetERKNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEES8_}
    [D] 'function arrow::Status arrow::compute::internal::FSBFilterExec(arrow::compute::KernelContext*, const arrow::compute::ExecSpan&, arrow::compute::ExecResult*)'    {_ZN5arrow7compute8internal13FSBFilterExecEPNS0_13KernelContextERKNS0_8ExecSpanEPNS0_10ExecResultE}

  6 Added functions:

    [A] 'method bool arrow::KeyValueMetadata::Contains(std::string_view) const'    {_ZNK5arrow16KeyValueMetadata8ContainsESt17basic_string_viewIcSt11char_traitsIcEE}
    [A] 'method arrow::Status arrow::KeyValueMetadata::Delete(std::string_view)'    {_ZN5arrow16KeyValueMetadata6DeleteESt17basic_string_viewIcSt11char_traitsIcEE}
    [A] 'method int arrow::KeyValueMetadata::FindKey(std::string_view) const'    {_ZNK5arrow16KeyValueMetadata7FindKeyESt17basic_string_viewIcSt11char_traitsIcEE}
    [A] 'method arrow::Result<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > > arrow::KeyValueMetadata::Get(std::string_view) const'    {_ZNK5arrow16KeyValueMetadata3GetB5cxx11ESt17basic_string_viewIcSt11char_traitsIcEE}
    [A] 'method arrow::Status arrow::KeyValueMetadata::Set(std::string, std::string)'    {_ZN5arrow16KeyValueMetadata3SetENSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEES6_}
    [A] 'function arrow::Status arrow::compute::internal::PrimitiveTakeExec(arrow::compute::KernelContext*, const arrow::compute::ExecSpan&, arrow::compute::ExecResult*)'    {_ZN5arrow7compute8internal17PrimitiveTakeExecEPNS0_13KernelContextERKNS0_8ExecSpanEPNS0_10ExecResultE}

================ end of changes of 'libarrow.so.1500.0.0'===============

Component(s)

C++

[kou]

@pitrou Could you take a look at this? It seems that we should have kept the backward compatibility in the PR to follow the semantic versioning.

[pitrou]

Ow... well, we could revert the KeyValueMetadata changes if we plan to do a new 15.0.x release.

[ianmcook]

FYI @raulcd

[amoeba]

I labeled this as a breaking change for the moment, since it seems to me that reverting the breaking change would be a breaking change too. If this isn't true (or if we don't revert the change) feel free to remove the label and probably leave a comment.

[pitrou]

Yes, reverting would also be a breaking change. Also, we're unlikely to do a 15.0.3 IMHO.

[kalebskeithley]

It doesn't appear that this was "fixed", i.e. the change reverted, in 16.0.0. Would it be correct to conclude that the API change is permanent?

[pitrou]

@kalebskeithley We don't guarantee any ABI stability across feature releases, so that is normal indeed.

[pitrou]

While this breakage was unfortunate, there's nothing that can be done anymore since the latest released version is 17.0.0. I'm therefore closing this issue. Sorry for the disruption!