[ARROW-13493] [C++] Anonymous structs in an anonymous union are a GNU extension

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 6.0.0, 5.0.1
• Component/s: C++, R
• Labels: pull-request-available
• External issue URL: https://github.com/apache/arrow/issues/29153
• Assignee: Niranda Perera
• Reporter: Neal Richardson
• Created: 29/Jul/21 19:23
• Updated: 11/Jan/23 08:33
• Resolved: 31/Jul/21 01:20

Description

CRAN reports on 5.0.0:

checking whether package ‘arrow’ can be installed ... [43m/20m] WARNING
Found the following significant warnings:
  /data/gannet/ripley/R/packages/tests-clang/arrow/libarrow/arrow-5.0.0/include/arrow/util/bitmap_reader.h:242:5: warning: anonymous structs are a GNU extension [-Wgnu-anonymous-struct]
  /data/gannet/ripley/R/packages/tests-clang/arrow/libarrow/arrow-5.0.0/include/arrow/util/bitmap_reader.h:242:5: warning: anonymous types declared in an anonymous union are an extension [-Wnested-anon-types]
  /data/gannet/ripley/R/packages/tests-clang/arrow/libarrow/arrow-5.0.0/include/arrow/util/bitmap_writer.h:263:5: warning: anonymous structs are a GNU extension [-Wgnu-anonymous-struct]
  /data/gannet/ripley/R/packages/tests-clang/arrow/libarrow/arrow-5.0.0/include/arrow/util/bitmap_writer.h:263:5: warning: anonymous types declared in an anonymous union are an extension [-Wnested-anon-types]
See https://www.r-project.org/nosvn/R.check/r-devel-linux-x86_64-fedora-clang/arrow-00install.html for details.

https://github.com/apache/arrow/blob/apache-arrow-5.0.0/cpp/src/arrow/util/bitmap_reader.h#L242-L247
https://github.com/apache/arrow/blob/apache-arrow-5.0.0/cpp/src/arrow/util/bitmap_writer.h#L263-L268

This change was introduced in ARROW-13010 (cc niranda)

Aside from the fix, I'm not sure which of the build settings on https://www.stats.ox.ac.uk/pub/bdr/Rconfig/r-devel-linux-x86_64-fedora-clang is missing from our `fedora-clang-devel` build we test on nightly, but we should figure it out (or work with the r-hub maintainers on making a better base image).

Issue Links

• depends upon: ARROW-13510 [CI][R][C++] Add -Wall to fedora-clang-devel as-cran checks
• links to: GitHub Pull Request #10833