[C++]: C++17 test PR

[pitrou]

Exercise some C++17 features to check platform support

[pitrou]

Small regression: our string_view backport includes C++20 features such as starts_with and ends_with.

[pitrou]

Started a crossbow build at https://github.com/ursacomputing/crossbow/branches/all?query=build-327

[pitrou]

New crossbow build at https://github.com/ursacomputing/crossbow/branches/all?query=build-329

[pitrou]

I really like that if constexpr can help avoid clumsy template specialization with SFINAE (see example in codegen_internal.h).

[pitrou]

Problem: R 4.0.5 on CentOS7 does not define configuration variables for C++ versions higher than C++11:

# R CMD config CXX11 g++
# R CMD config CXX14
# R CMD config CXX17
# R CMD config CXX11FLAGS
-g -O2
# R CMD config CXX14FLAGS
# R CMD config CXX17FLAGS
# R CMD config CXX11STD
-std=gnu++11
# R CMD config CXX14STD
# R CMD config CXX17STD

[nealrichardson]

Problem: R 4.0.5 on CentOS7 does not define configuration variables for C++ versions higher than C++11:

Bad config in the docker image? Or this is because it is gcc 4.8? (We have a crossbow job that does centos7 with devtoolset-8)

[pitrou]

What do you mean? These are the results of the R command.

[pitrou]

Ah, indeed I see this in the build logs:

-- Building using CMake version: 3.19.2
-- The C compiler identification is GNU 4.8.5

https://github.com/apache/arrow/pull/10414/checks?check_run_id=2687678135#step:9:69

[nealrichardson]

What do you mean? These are the results of the R command.

Right, those commands read from R's Makeconf. If the compiler doesn't support C++14 or C++17, it's reasonable to expect that those makevars would be undefined.

[bkietz]

Debian 9 (builds JNI) has only gcc 6.3, which doesn't have <string_view>. https://wandbox.org/permlink/bijOi9BHbk3HXqiA In general it seems to lack a number of c++17 features

[kszucs]

Debian 9 (builds JNI) has only gcc 6.3, which doesn't have <string_view>. https://wandbox.org/permlink/bijOi9BHbk3HXqiA In general it seems to lack a number of c++17 features

We should bump the debian version to 10 in those docker images (which is the default in .env but hardcoded in the java images). We may need to bump the JDK and mvn versions as well due to newer debian. If we wan't to keep builds for the current JDK and mvn versions then we can still parametrize that we test debian-java with DEBIAN=9 and debian-java-jni with DEBIAN=10.

I'm going to update the configuration.

[bkietz]

I've pushed two commits removing the util::string_view and util::optional aliases; some of the older compilers seemed to have trouble with those.

[kszucs]

@bkietz we have a couple more compile errors in the c-glib builds and on appveyor.

[pitrou]

Submitted crossbow builds:
https://github.com/ursacomputing/crossbow/branches/all?query=build-360
https://github.com/ursacomputing/crossbow/branches/all?query=build-361

[jeroen]

CRAN targets MacOS 10.13 (xcode10.1). Did anyone test if this version of xcode supports C++17?

[nealrichardson]

@jeroen there are a number of packages on CRAN that use C++17 already, aren't there?

[nealrichardson]

hmm, fewer than I thought:

> table(grepl("C++17", tools::CRAN_package_db()$SystemRequirements, fixed = TRUE))
FALSE TRUE 17691 3 

[jeroen]

Yes I think so, but that does not guarantee that the given compilers support the full c++17 feature set. Perhaps it would be good to add a travis build with:

os: osx
osx_image: xcode10.1

Afaik there is no other CI supporting older versions of MacOS.

[jeroen]

I tried building this PR on macos 10.13 but it failed as follows (current master HEAD is fine):

[ 16%] Building CXX object src/arrow/dataset/CMakeFiles/arrow_dataset_objlib.dir/file_ipc.cc.o
cd /tmp/apache-arrow-20210608-10068-17s4hhj/build/src/arrow/dataset && /Users/builder/Desktop/brew/Library/Homebrew/shims/mac/super/clang++ -DARROW_DS_EXPORTING -DARROW_HAVE_RUNTIME_AVX2 -DARROW_HAVE_RUNTIME_AVX512 -DARROW_HAVE_RUNTIME_BMI2 -DARROW_HAVE_RUNTIME_SSE4_2 -DARROW_HAVE_SSE4_2 -DARROW_JEMALLOC -DARROW_JEMALLOC_INCLUDE_DIR="" -DARROW_MIMALLOC -DARROW_WITH_LZ4 -DARROW_WITH_RE2 -DARROW_WITH_SNAPPY -DARROW_WITH_TIMING_TESTS -DARROW_WITH_UTF8PROC -DARROW_WITH_ZLIB -DARROW_WITH_ZSTD -DURI_STATIC_BUILD -DUTF8PROC_STATIC -I/tmp/apache-arrow-20210608-10068-17s4hhj/build/src -I/tmp/apache-arrow-20210608-10068-17s4hhj/cpp/src -I/tmp/apache-arrow-20210608-10068-17s4hhj/cpp/src/generated -I/tmp/apache-arrow-20210608-10068-17s4hhj/cpp/src/parquet -isystem /tmp/apache-arrow-20210608-10068-17s4hhj/cpp/thirdparty/flatbuffers/include -isystem /Users/builder/Desktop/brew/Cellar/thrift/0.11.0/include -isystem /tmp/apache-arrow-20210608-10068-17s4hhj/build/jemalloc_ep-prefix/src -isystem /tmp/apache-arrow-20210608-10068-17s4hhj/build/mimalloc_ep/src/mimalloc_ep/lib/mimalloc-1.6/include -isystem /tmp/apache-arrow-20210608-10068-17s4hhj/build/rapidjson_ep/src/rapidjson_ep-install/include -isystem /tmp/apache-arrow-20210608-10068-17s4hhj/build/xsimd_ep/src/xsimd_ep-install/include -isystem /Users/builder/Desktop/brew/Cellar/lz4/1.8.3/include -isystem /Users/builder/Desktop/brew/Cellar/zstd/1.3.5/include -isystem /tmp/apache-arrow-20210608-10068-17s4hhj/build/re2_ep-install/include -isystem /tmp/apache-arrow-20210608-10068-17s4hhj/build/utf8proc_ep-install/include -isystem /tmp/apache-arrow-20210608-10068-17s4hhj/cpp/thirdparty/hadoop/include -Qunused-arguments -fcolor-diagnostics -O3 -DNDEBUG -Wall -Wno-unknown-warning-option -Wno-pass-failed -stdlib=libc++ -msse4.2 -DNDEBUG -fPIC -std=c++17 -o CMakeFiles/arrow_dataset_objlib.dir/file_ipc.cc.o -c /tmp/apache-arrow-20210608-10068-17s4hhj/cpp/src/arrow/dataset/file_ipc.cc
/tmp/apache-arrow-20210608-10068-17s4hhj/cpp/src/arrow/dataset/file_base.cc:77:38: error: call to unavailable member function 'value': introduced in macOS 10.14
actual_compression = compression.value();
~~~~~~~~~~~~^~~~~
/Library/Developer/CommandLineTools/usr/include/c++/v1/optional:942:27: note: candidate function has been explicitly made unavailable
constexpr value_type& value() &
^
/Library/Developer/CommandLineTools/usr/include/c++/v1/optional:933:33: note: candidate function has been explicitly made unavailable
constexpr value_type const& value() const&
^
/Library/Developer/CommandLineTools/usr/include/c++/v1/optional:951:28: note: candidate function not viable: no known conversion from 'optional<...>' to 'optional<...>' for object argument
constexpr value_type&& value() &&
^
/Library/Developer/CommandLineTools/usr/include/c++/v1/optional:960:34: note: candidate function not viable: no known conversion from 'optional<...>' to 'const optional<...>' for object argument
constexpr value_type const&& value() const&&
^

[bkietz]

@jeroen does it work if we replace calls to optional::value() with optional::operator*?

[jeroen]

How exactly do I do that? I tried literally substituting that line and that errors with:

file_base.cc:77:26: error: 'compression' is not a class, namespace, or enumeration
actual_compression = compression::optional::operator*;

[nealrichardson]

Closing as stale