[ARROW-2655] [C++] Failure with -Werror=conversion on gcc 7.3.0

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 0.10.0
• Component/s: C++
• Labels: pull-request-available
• External issue URL: https://github.com/apache/arrow/issues/19049
• Assignee: Wes McKinney
• Reporter: Wes McKinney
• Created: 31/May/18 20:39
• Updated: 11/Jan/23 07:22
• Resolved: 04/Jun/18 01:19

Description

Experienced this error building on Ubuntu 18.04 LTS / gcc 7.3.0

/usr/bin/ccache /usr/bin/g++  -DARROW_EXTRA_ERROR_CONTEXT -DARROW_NO_DEPRECATED_API -isystem /home/wesm/cpp-toolchain/include -isystem gbenchmark_ep/src/gbenchmark_ep-install/include -isystem ../thirdparty/hadoop/include -isystem orc_ep-install/include -Isrc -I../src -isystem /home/wesm/miniconda/envs/arrow-dev/lib/python3.6/site-packages/numpy/core/include -isystem /home/wesm/miniconda/envs/arrow-dev/include/python3.6m -D_GLIBCXX_USE_CXX11_ABI=0 -ggdb -O0  -Wall -Wconversion -Wno-sign-conversion -Wno-unknown-warning-option -Werror -std=c++11 -msse3 -Werror -g -fPIC   -std=gnu++11 -MD -MT src/arrow/python/CMakeFiles/arrow_python_objlib.dir/arrow_to_pandas.cc.o -MF src/arrow/python/CMakeFiles/arrow_python_objlib.dir/arrow_to_pandas.cc.o.d -o src/arrow/python/CMakeFiles/arrow_python_objlib.dir/arrow_to_pandas.cc.o -c ../src/arrow/python/arrow_to_pandas.cc
In file included from ../src/arrow/compute/kernel.h:28:0,
                 from ../src/arrow/compute/api.h:22,
                 from ../src/arrow/python/arrow_to_pandas.cc:46:
../src/arrow/util/variant.h:588:67: error: conversion to ‘unsigned int’ from ‘long unsigned int’ may alter its value [-Werror=conversion]
     static const std::size_t data_size = detail::static_max<sizeof(Types)...>::value;
                                                                   ^
../src/arrow/util/variant.h:589:79: error: conversion to ‘unsigned int’ from ‘long unsigned int’ may alter its value [-Werror=conversion]
     static const std::size_t data_align = detail::static_max<alignof(Types)...>::value;
                                                                               ^
cc1plus: error: unrecognized command line option ‘-Wno-unknown-warning-option’ [-Werror]
cc1plus: all warnings being treated as errors

Issue Links

• links to: GitHub Pull Request #2095