[Caml-list] Mingw-ocaml and C++

[Romain Beauxis <toots@rastageeks.org>]

Hi all,

I have extracted the debian-specific build for mingw-ocaml into a
standalone build:
  https://github.com/savonet/mingw-ocaml

You should be able to use it to build mingw-ocaml for windows 32 and
64 bit. It has been updated with the latest ocaml (4.00.1) and flexdll
(0.30)

However, I am having some serious trouble with C++ FlexDLL linking on
Debian wheezy and sid.

This is a problem that occurs when building OCaml modules based on C++
libraries. Here's a simple way to reproduce. It does not involve OCaml
but showcases the exact issue I am having with libraries and is damn
simple:

- Install mingw-ocaml or compile it from the sources above. Doesn't
matter the version, bug is the same.

- Create this file:

% cat hello.cpp
#include <iostream>

int main()
{
  std::cout << "Hello World!" << std::endl;
  return 0;
}

- Compile it:

% i686-w64-mingw32-g++ -c hello.cpp

- Link it with gcc:
% i686-w64-mingw32-gcc -o hello.exe ./hello.o -lstdc++

- Try to link it with flexlink:

% flexlink -exe -chain mingw -L/usr/i686-w64-mingw32/lib  -o
hello-flexlink.exe -lstdc++ hello.o -v -v -v
** Use cygpath: false
** Search path:
/usr/i686-w64-mingw32/lib
/usr/lib/gcc/i686-w64-mingw32/4.6
/mingw/lib
** Default libraries:
crt2.o
-lmingw32
-lgcc
-lmoldname
-lmingwex
-lmsvcrt
-luser32
-lkernel32
-ladvapi32
-lshell32
** Cannot resolve symbols for hello.o:
 __ZSt4cout
** open: /usr/i686-w64-mingw32/lib/crt2.o
** open: /usr/i686-w64-mingw32/lib/libmingw32.a
** open: /usr/lib/gcc/i686-w64-mingw32/4.6/libgcc.a
** open: /usr/i686-w64-mingw32/lib/libmoldname.a
** open: /usr/i686-w64-mingw32/lib/libmingwex.a
** open: /usr/i686-w64-mingw32/lib/libmsvcrt.a
** open: /usr/i686-w64-mingw32/lib/libuser32.a
** open: /usr/i686-w64-mingw32/lib/libkernel32.a
** open: /usr/i686-w64-mingw32/lib/libadvapi32.a
** open: /usr/i686-w64-mingw32/lib/libshell32.a
zsh: exit 2     flexlink -exe -chain mingw -L/usr/i686-w64-mingw32/lib
-o hello.exe -lstdc++

Any input or directions to grab more information would be greatly
welcome as I am pretty dry on how to fix this issue currently..

Thanks!
Romain