Add support for Perl built with C++

[pmqs]

For Perl XS modules, particularly those in the core, you need your module to support being build with a Perl binary created with a C++ compiler.

I'm just updating Compress-Raw-Zlib with a C- related change that gets stung with this use-case more often that I'd like. The typical workflow goes like tis

• I update the module, forgetting to test the C++ use case
• code gets uploaded to CPAN
• the smokes run but they fail with the C++ builds
• I scramble to fix the issue & upload a to CPAN

I have all of the use-cases I need cooked into my GitHub actions, but this one is missing. Any chance of adding C++ support?

[shogo82148]

I have never built Perl with C++.
How do I do that?

[pmqs]

At the configure stage just use Dcc to use a C++ compiler rather that the default C compiler.

configure -Dcc=g++ ...

or this for clang

configure -Dcc=clang++ ...

[shogo82148]

I did.
However, I don't want to add more variant of perl binaries.

[tonycoz]

@pmqs you should be able to test C++ builds sufficient for updating your modules in core by replacing:

perl Makefile.PL

line in your workflow file with:

perl Makefile.PL CC=g++

[pmqs]

@pmqs you should be able to test C++ builds sufficient for updating your modules in core by replacing:

perl Makefile.PL

line in your workflow file with:

perl Makefile.PL CC=g++

Thanks @tonycoz

Part of the reason for wanting the C++ mode is to trap compiler errors & warnings in a build that I always forget to do when I'm getting a release together. The CC=g++ change works fine with the Linux gcc workflow, but the Mac workflow triggers a clang built Perl, so the CC=clang++ build that also include -Werror triggers this

clang: error: treating 'c' input as 'c++' when in C++ mode, this behavior is deprecated [-Werror,-Wdeprecated]

That feels like a wider issue with building Perl with C++ in general that is going to cause problems when clang drop building C code with their C++ compiler.

[tonycoz]

For your purposes you can probably do:

perl Makefile.PL CC="clang++ -xc++"

unfortunately that doesn't work when building perl itself (which I tried to fix in Perl/perl5@07e3b5c but had to revert in Perl/perl5@0c77b72)

[pmqs]

For your purposes you can probably do:

perl Makefile.PL CC="clang++ -xc++"

unfortunately that doesn't work when building perl itself (which I tried to fix in Perl/perl5@07e3b5c but had to revert in Perl/perl5@0c77b72)

That's a good option. Didn't see that one in the clang docs. Another option I investigated was -Wno-error=deprecated but that doesn't silence the warning, plus it hides other possible deprecations.

Another option I use with C builds is -Wc++-compat