error: no member named 'log2p1' in namespace 'std'

[ryandesign]

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

Apache Arrow 24.0.0 fails to build for me on macOS 12:

/usr/bin/clang++ -DARROW_EXTRA_ERROR_CONTEXT -DARROW_HAVE_RUNTIME_AVX2 -DARROW_HAVE_RUNTIME_AVX512 -DARROW_HAVE_RUNTIME_BMI2 -DARROW_HAVE_RUNTIME_SSE4_2 -DARROW_HAVE_SSE4_2 -DARROW_WITH_TIMING_TESTS -I/opt/local/var/macports/build/apache-arrow-3893d460/work/build/src -I/opt/local/var/macports/build/apache-arrow-3893d460/work/arrow-24.0.0/cpp/src -I/opt/local/var/macports/build/apache-arrow-3893d460/work/arrow-24.0.0/cpp/src/generated -fno-aligned-new -pipe -I/opt/local/libexec/boost/1.81/include -Os -DNDEBUG -I/opt/local/libexec/boost/1.81/include -I/opt/local/include -stdlib=libc++ -isysroot/Library/Developer/CommandLineTools/SDKs/MacOSX12.sdk -Qunused-arguments -fcolor-diagnostics  -Wall -Wno-unknown-warning-option -Wno-pass-failed -msse4.2  -O3 -DNDEBUG -O2  -std=c++20 -arch x86_64 -isysroot /Library/Developer/CommandLineTools/SDKs/MacOSX12.sdk -mmacosx-version-min=12.0 -fPIC -MD -MT src/arrow/CMakeFiles/arrow_array.dir/array/array_decimal.cc.o -MF src/arrow/CMakeFiles/arrow_array.dir/array/array_decimal.cc.o.d -o src/arrow/CMakeFiles/arrow_array.dir/array/array_decimal.cc.o -c /opt/local/var/macports/build/apache-arrow-3893d460/work/arrow-24.0.0/cpp/src/arrow/array/array_decimal.cc
In file included from /opt/local/var/macports/build/apache-arrow-3893d460/work/arrow-24.0.0/cpp/src/arrow/array/array_decimal.cc:18:
In file included from /opt/local/var/macports/build/apache-arrow-3893d460/work/arrow-24.0.0/cpp/src/arrow/array/array_decimal.h:24:
In file included from /opt/local/var/macports/build/apache-arrow-3893d460/work/arrow-24.0.0/cpp/src/arrow/array/array_binary.h:30:
In file included from /opt/local/var/macports/build/apache-arrow-3893d460/work/arrow-24.0.0/cpp/src/arrow/array/array_base.h:26:
In file included from /opt/local/var/macports/build/apache-arrow-3893d460/work/arrow-24.0.0/cpp/src/arrow/array/data.h:33:
/opt/local/var/macports/build/apache-arrow-3893d460/work/arrow-24.0.0/cpp/src/arrow/util/bit_util.h:146:15: error: no member named 'log2p1' in namespace 'std'
  return std::log2p1(x - 1);
         ~~~~~^
1 error generated.

System details:

% sw_vers
ProductName:	macOS
ProductVersion:	12.7.6
BuildVersion:	21H1320

% clang++ --version
Apple clang version 13.1.6 (clang-1316.0.21.2.5)
Target: x86_64-apple-darwin21.6.0
Thread model: posix
InstalledDir: /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin

% xcodebuild -version
Xcode 13.4.1
Build version 13F100

bit_width exists in the headers and log2p1 does not:

% grep -E '(bit_width|log2p1)' -r /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/usr/include
/Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/usr/include/c++/v1/bit:    constexpr T bit_width(T x) noexcept;         // C++20
/Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/usr/include/c++/v1/bit:bit_width(_Tp __t) noexcept

On the same system, Apache Arrow 23.0.1 had built successfully.

Apache Arrow 24.0.0 contains #49570 to fix #49569. I guess in fixing it for macOS 14 it broke for macOS 12.

Instead of having multiple places in the source code where you try to decide between bit_width and log2p1 based on assumed knowledge of compiler capabilities, could you determine it with a cmake test and then use that result throughout?

Component(s)

C++