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=head1 NAME |
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|
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ExtUtils::CXX - support C++ XS files |
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|
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=head1 SYNOPSIS |
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|
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use ExtUtils::CXX; |
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use ExtUtils::MakeMaker; |
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|
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# wrap calls to WriteMakefile or MakeMaker that are supposed to use |
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# C++ XS files into extutils_cxx blocks: |
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|
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extutils_cxx { |
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WriteMakefile ( |
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... put your normal args here |
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); |
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}; |
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|
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=head1 DESCRIPTION |
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|
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This module enables XS extensions written in C++. It is meant to be useful |
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for the users and installers of c++ modules, rather than the authors, by |
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having a single central place where to patch things, rather than to have |
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to patch every single module that overrides CC manually. That is, in the |
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worst case, you need to patch this module for your environment before |
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being able to CPAN-install further C++ modules; commonly, only setting a |
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few ENV variables is enough; and in the best case, it just works out of |
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the box. |
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|
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(Comments on what to do and suggestions on how to achieve these things |
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better are welcome). |
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|
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At the moment, it works by changing the values in C<%Config::Config> |
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temporarily. It does the following things: |
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|
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=over 4 |
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|
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=item 1. It tries to change C<$Config{cc}> and C<$Config{ld}> into a C++ compiler. |
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|
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If the environment variable C<$CXX> is set, then it's value will be used |
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to replace both (except if C<$PERL_CXXLD> is set, then that will be used for |
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C<$Config{ld}>. |
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|
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(There is also a C<$PERL_CXX> which takes precedence over C<$CXX>). |
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|
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The important thing is that the chosen C++ compiler compiles files with |
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a F<.c> ending as C++ - a generic compiler wrapper such as F<gcc> that |
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detects the language by the file extension will I<not> work. |
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|
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In the absence of these variables, it will do the following |
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transformations on what it guesses will be the compiler name: |
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|
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gcc => g++ |
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clang => clang++ |
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xlc => xlC |
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cc => g++ |
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c89 => g++ |
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perlcc => perlc++ |
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|
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=back |
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|
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=over 4 |
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|
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=cut |
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|
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package ExtUtils::CXX; |
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|
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use common::sense; |
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|
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our $VERSION = '1.0'; |
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|
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use Exporter 'import'; |
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|
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our @EXPORT = qw(extutils_cxx); |
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|
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use ExtUtils::MakeMaker::Config (); |
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|
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=item extutils_cxx BLOCK; |
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|
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This function temporarily does hideous things so you can call |
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C<WriteMakefile> or similar functions in the BLOCK normally. See the |
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description, above, for more details. |
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|
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=cut |
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|
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use Config; |
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|
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our %cc = ( |
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gcc => "g++", |
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clang => "clang++", |
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xlc => "xlC", |
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cc => "g++", |
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c89 => "g++", |
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perlcc => "perlc++", |
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); |
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|
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our $PREFIX = qr{(?:\S+[\/\\])? (?:ccache|distcc)}x; |
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|
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sub _ccrepl { |
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my ($cfgvar, $env) = @_; |
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|
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my $tie = tied %Config; |
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|
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my $env = $ENV{"PERL_$env"} || $ENV{$env}; |
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|
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my $val = $tie->{$cfgvar}; |
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|
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if ($env) { |
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$val =~ s/^\S+/$env/; |
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} else { |
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keys %cc; |
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while (my ($k, $v) = each %cc) { |
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$val =~ s/^ ((?:$PREFIX\s+)? \S*[\/\\])? $k (-|\s|\d|$) /$1$v$2/x |
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and goto done; |
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} |
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|
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$val =~ s/^($PREFIX\s+)? \S+/$1g++/x; |
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|
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done: ; |
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} |
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|
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$tie->{$cfgvar} = $val; |
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} |
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|
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sub extutils_cxx(&) { |
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my ($cb) = @_; |
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|
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# make sure these exist |
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@Config{qw(cc ld)}; |
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|
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my $tie = tied %Config; |
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|
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# now dive into internals of Config and temporarily patch those values |
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|
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local $tie->{cc} = $Config{cc}; _ccrepl cc => "CXX"; |
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local $tie->{ld} = $Config{ld}; _ccrepl ld => ($ENV{PERL_CXXLD} ? "CXXLD" : "CXX"); |
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|
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local $ExtUtils::MakeMaker::Config::Config{cc} = $tie->{cc}; |
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local $ExtUtils::MakeMaker::Config::Config{ld} = $tie->{ld}; |
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|
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eval { |
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$cb->(); |
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}; |
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die if $@; |
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} |
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|
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=back |
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|
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=head2 WHAT YOU HAVE TO DO |
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|
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This module only makes your F<.xs> files compile as C++. It does not |
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provide magic C++ support for objects and typemaps, and does not help with |
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portability or writing your F<.xs> file. All of these you have to do - |
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google is your friend. |
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|
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=head2 LIMITATIONS |
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|
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Combining C++ and C is an art form in itself, and there is simply no |
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portable way to make it work - the platform might have a C compiler, but |
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no C++ compiler. The C++ compiler might be binary incompatible to the C |
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compiler, or might not run for other reasons, and in the end, C++ is more |
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of a moving target than C. |
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|
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=head2 SEE ALSO |
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|
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There is a module called C<ExtUtils::XSpp> that says it gives you C++ in |
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XS, by changing XS in some ways. I don't know what exactly it's purpose |
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is, but it might be a useful addition for C++ Xs development for you, |
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so you might want to look at it. It doesn't have C<ExtUtils::MakeMaker> |
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support, and there is a companion module that only supports the obsolete |
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(and very broken) C<Module::Build>, sour YMMV. |
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|
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=head1 AUTHOR/CONTACT |
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|
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Marc Lehmann <schmorp@schmorp.de> |
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http://software.schmorp.de/pkg/extutils-cxx.html |
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|
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=cut |
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|
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1 |
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