Strawberry perl + Inline::CPP + <sstream> not compiled

Question

maybe somebody can help me to understand. why this error occurs. I am trying to build C++ code, that use using Inline::CPP.

Here is the example:

#!/usr/bin/env perl

package main v0.1.0;

use strict;
use warnings;

use Inline(
    CPP => <<'CPP',
#undef seekdir

#include <sstream>
CPP
    # ccflags           => '-std=c++11',
    ccflags           => '-std=gnu++11',
    clean_after_build => 0,
    clean_build_area  => 0,
);

1;
__END__

This code compiled without errors under linux, but under strawberry perl 5.26.2 x64 it produce following error:

"D:\devel\perl\perl\bin\perl.exe" -MExtUtils::Command -e mv -- _2_pl_0f1f.xsc _2_pl_0f1f.c
g++  -s -O2 -DWIN32 -DWIN64 -DCONSERVATIVE -D__USE_MINGW_ANSI_STDIO -DPERL_TEXTMODE_SCRIPTS -DPERL_IMPLICIT_CONTEXT -DPERL_IMPLICIT_SYS -DUSE_PERLIO -fwrapv -fno-strict-aliasing -mms-bitfields  -xc++ -c  -I"D:/downloads/cpp-adaptive/cppAdaptive2/inline-src" -std=gnu++11 -s -O2   -DVERSION=\"0.00\" -DXS_VERSION=\"0.00\"  "-ID:\devel\perl\perl\lib\CORE"   _2_pl_0f1f.c
In file included from _2_pl_0f1f.xs:11:0:
D:\devel\perl\perl\lib\CORE/perl.h:3544:45: error: expected ')' before '*' token
 #    define PERL_GET_THX  ((PerlInterpreter *)PERL_GET_CONTEXT)
                                         ^
D:\devel\perl\perl\lib\CORE/perl.h:3544:45: error: expected ')' before '*' token
D:\devel\perl\perl\lib\CORE/perl.h:3544:45: error: expected ')' before '*' token
D:\devel\perl\perl\lib\CORE/perl.h:3544:45: error: expected ')' before '*' token
D:\devel\perl\perl\lib\CORE/perl.h:3544:29: error: expected ';' at end of member declaration
 #    define PERL_GET_THX  ((PerlInterpreter *)PERL_GET_CONTEXT)

... and so on ...

Maybe somebody already solved similar problems?

Answer 1

This error occurs because <sstream> happens to use setbuf in an inline function, which one of the implicitly added headers (maybe XSUB.h or perl.h?) has redefined (using a preprocessor #define).

This redefinition breaks loudly because it uses the PerlInterpreter type, which is defined in a different namespace and not visible here (macros ignore namespaces, of course).

You can get the code to compile by adding

#undef setbuf

before including <sstream>.