Name conflict between MinGW C++ standard library header and Perl development header

llancet has asked for the wisdom of the Perl Monks concerning the following question:

My project compiles OK on several Linux platforms. But when I compile it under windows, it claims the following error:

In file included from D:/Strawberry-5.20.1.1-ia32/c/i686-w64-mingw32/i
+nclude/c++/iostream:39:0,
                 from D:/mydoc/projects/GenoEye-0.4.5-Source/src/genoe
+ye/Common.h:9,
                 from D:\mydoc\projects\GenoEye-0.4.5-Source\perl\geno
+eye_perl.h:9,
                 from D:\mydoc\projects\GenoEye-0.4.5-Source\perl\geno
+eye_perl.cpp:1:
D:/Strawberry-5.20.1.1-ia32/c/i686-w64-mingw32/include/c++/ostream:335
+:49: error: macro "PerlLIO_write" requires 3 arguments, but on
ly 2 given
       write(const char_type* __s, streamsize __n);
[download]

This is the content around ostream line 335:

      /**
       *  @brief  Character string insertion.
       *  @param  __s  The array to insert.
       *  @param  __n  Maximum number of characters to insert.
       *  @return  *this
       *
       *  Characters are copied from @p __s and inserted into the stre
+am until
       *  one of the following happens:
       *
       *  - @p __n characters are inserted
       *  - inserting into the output sequence fails (in this case, ba
+dbit
       *    will be set in the stream's error state)
       *
       *  @note  This function is not overloaded on signed char and
       *         unsigned char.
      */
      __ostream_type&
      write(const char_type* __s, streamsize __n);
[download]

and this is the beginning of genoeye_perl.h, which includes both Perl headers and C++ headers:

extern "C"
{
#include "EXTERN.h"
#include "perl.h"
#include "XSUB.h"
#include "ppport.h"
}

#include <genoeye/Common.h>
#include <genoeye/Page.h>
#include <genoeye/Frame.h>
#include <genoeye/Track.h>
#include <genoeye/Segment.h>
#include <genoeye/Elem.h>
#include <genoeye/Block.h>
#include <genoeye/Tag.h>
#include <genoeye/Chart.h>
#include <genoeye/HomologRegion.h>
#include <genoeye/ElemConnect.h>
[download]

the "write" function declaration is probably conflict with Perl's internal definition. How can I solve this problem?

I'm using the MinGW toolchain provided with strawberry perl 5.20.1.1. This issue also occurs with older versions of strawberry perl.

------

Pretty sad, simply undefine the Perl-induced macro don't work

extern "C"
{
#include "EXTERN.h"
#include "perl.h"
#include "XSUB.h"
#include "ppport.h"
}

#undef write

#include <genoeye/Common.h>
......
[download]

This does not change anything. This is very suprise.

Comment on Name conflict between MinGW C++ standard library header and Perl development header Select or Download Code

Replies are listed 'Best First'.
Re: Name conflict between MinGW C++ standard library header and Perl development header by syphilis (Archbishop) on Nov 11, 2014 at 07:12 UTC
The problem is that XSUB.h contains: `#define write PerlLIO_write` [download] What happens if you #include the genoeye headers before XSUB.h gets included ? Another thing you could try is to undef write prior to #including the genoeye headers: `#ifdef write #undef write #endif #include <genoeye/Common.h> #include <genoeye/Page.h> ....` [download] And the other thing you could try is to wait for better advice ;-) Cheers, Rob	[reply] [d/l] [select]
Re^2: Name conflict between MinGW C++ standard library header and Perl development header by davido (Cardinal) on Nov 11, 2014 at 07:16 UTC
And the other* thing you could try is to wait for better advice ;-)* Naw, I like this advice. I almost posted something similar, because I have also found that it is sometimes useful to `#undef` away a macro conflict in these situations. It's a good suggestion (unless it doesn't work). I hesitated in posting the thought because I figured someone would have a better idea. ;) Dave	[reply] [d/l]
Re^3: Name conflict between MinGW C++ standard library header and Perl development header by syphilis (Archbishop) on Nov 11, 2014 at 07:24 UTC
Is the idea of loading the genoeye headers before loading the perl headers likely to be helpful ? It certainly breaks the conventional way of doing things (and I don't think I've ever tried it), but it's probably the safest solution ...... if it works. Cheers, Rob	[reply]
Re^4: Name conflict between MinGW C++ standard library header and Perl development header by llancet (Friar) on Nov 11, 2014 at 10:37 UTC
Re^2: Name conflict between MinGW C++ standard library header and Perl development header by llancet (Friar) on Nov 11, 2014 at 10:25 UTC
Why I don't got this issue while compiling same code under Linux?	[reply]
Re^3: Name conflict between MinGW C++ standard library header and Perl development header by syphilis (Archbishop) on Nov 11, 2014 at 11:09 UTC
Why I don't got this issue while compiling same code under Linux? Does "write" get defined to PerlLIO_write for you in Linux ? `use strict; use warnings; use Inline C => <<'EOC'; int foo() { #ifdef write return 1; #else return 0; #endif } EOC print foo();` [download] All Inline::C scripts automatically load XSUB.h - hence no need to specifically #include that header. That script outputs 1 for me on Windows, but 0 for me on Debian Wheezy. Cheers, Rob	[reply] [d/l]
Re^2: Name conflict between MinGW C++ standard library header and Perl development header by llancet (Friar) on Nov 11, 2014 at 11:43 UTC
It does not work. The same error occurs... That is pretty suprising: why I undef the macro, but it is still seen by latter code?	[reply]
Re^3: Name conflict between MinGW C++ standard library header and Perl development header by syphilis (Archbishop) on Nov 11, 2014 at 12:25 UTC
The same error occurs It shouldn't be exactly the same error. I think `D:\mydoc\projects\GenoEye-0.4.5-Source\perl\genoeye_perl.h:9` [download] should have become: `D:\mydoc\projects\GenoEye-0.4.5-Source\perl\genoeye_perl.h:11` [download] Otherwise the modified file was not found. Cheers, Rob	[reply] [d/l] [select]
Re^4: Name conflict between MinGW C++ standard library header and Perl development header by llancet (Friar) on Nov 12, 2014 at 00:52 UTC
Re^5: Name conflict between MinGW C++ standard library header and Perl development header by syphilis (Archbishop) on Nov 12, 2014 at 04:29 UTC
Re^2: Name conflict between MinGW C++ standard library header and Perl development header by llancet (Friar) on Nov 12, 2014 at 08:38 UTC
The issue is located to perl.h, not XSUB.h: `#include "perl.h" #include <iostream> int main() { std::cout << "foo" << std::endl; }` [download] and compile with: D:\mydoc\projects\GenoEye-0.4.5-build\perl>g++ -ID:/gtk+-2.24.10/inclu +de/cairo -ID:/gtk+-2.24.10/include/glib-2.0 -ID:/gtk+-2.24.10/ lib/glib-2.0/include -ID:/gtk+-2.24.10/include -ID:/gtk+-2.24.10/inclu +de/freetype2 -ID:/gtk+-2.24.10/include/libpng14 -ID:/mydoc/pro jects/GenoEye-0.4.5-Source/src -ID:/mydoc/projects/GenoEye-0.4.5-build +/src -ID:/mydoc/projects/GenoEye-0.4.5-Source -ID:/Strawberry- 5.20.1.1-ia32/perl/lib/CORE -ID:/mydoc/projects/GenoEye-0.4.5-Source/p +erl -g -o test.exe test.cpp [download] it will reproduce this issue. Also, add `#undef write` before `#include <iostream>` won't help. However, this conflict do not reproduce if I use Inline::CPP. The code below works well: `use strict; use Inline 'CPP' => config => BUILD_NOISY => 1, INC => '-ID:/mydoc/projects/GenoEye-0.4.5-Source/src -ID:/mydoc/p +rojects/GenoEye-0.4.5-Source/perl -ID:/gtk+-2.24.10/include/cairo'; foobar(); use Inline 'CPP' => <<'CODE'; #include <perl.h> #include <iostream> void foobar() { std::cout << "foobar" << std::endl; } CODE` [download] Why there's such big difference? I cannot understand it...	[reply] [d/l] [select]
Re^3: Name conflict between MinGW C++ standard library header and Perl development header by syphilis (Archbishop) on Nov 12, 2014 at 09:34 UTC
Why there's such big difference? I cannot understand it... (Yeah ... sorry, not much point running Inline::C scripts when we're dealing with something that's specific to Inline::CPP ;-) I don't grok C++, and I can only assume that in your simplified Inline::CPP script, the write() call in ostream has not been made visible. It's definite that 'write' has been defined to 'PerlLIO_write' - just try to use write() in your Inline::CPP script and you'll be able to verify: `use strict; use Inline 'CPP' => config => BUILD_NOISY => 1; foobar(); use Inline 'CPP' => <<'CODE'; #include <perl.h> // not needed - gets included automatically #include <iostream> void foobar() { std::cout << "foobar" << std::endl; } void break_me(SV * a, SV * b) { write(a, b); } CODE` [download] That generates the error: `try_pl_dec5.xs:28:14: error: macro "PerlLIO_write" requires 3 argument +s, but only 2 given write(a, b);` [download] In ostream, the `write()` declaration is preceded (next line up) by `__ostream_type&`. I don't know whether that puts aome sort of condition upon whether the function is visible or not. Maybe if you include the same headers in the compilation of your Inline::CPP script as were used for the C++ script then things might start to add up correctly. I know it's messy ... XS is like that, but you just have to work through it. Cheers, Rob	[reply] [d/l] [select]
Re^4: Name conflict between MinGW C++ standard library header and Perl development header by llancet (Friar) on Nov 13, 2014 at 09:48 UTC
Re^3: Name conflict between MinGW C++ standard library header and Perl development header by Anonymous Monk on Nov 12, 2014 at 08:50 UTC
Why there's such big difference? I cannot understand it... Um, Inline generates XS, look at it and note the differences, right?	[reply]