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c++openglmingw-w64msys2

Compiling a program under Windows gives a bunch of "error: template with C linkage" reports

I have made an OpenGL project compilable with GCC (version 4.7.3 and newer) and runable on Linux. When trying to compile the same code under Windows using MSYS2 with GCC 4.9.2 installed, I get tons of error reports:

g++ -g --std=c++11 src/*.cpp -Iinclude -Isrc -lIL -lILU -lILUT -lGL -lGLU -lglut -lm -DWIN32 -I/mingw64/include windows/src/*.cpp -o "Achtung, die Kurve 3D!"
In file included from /usr/lib/gcc/x86_64-pc-msys/4.9.2/include/c++/bits/stringfwd.h:40:0,
                 from /usr/lib/gcc/x86_64-pc-msys/4.9.2/include/c++/string:39,
                 from include/windows.h:1,
                 from /usr/include/w32api/GL/gl.h:13,
                 from /mingw64/include/GL/freeglut_std.h:143,
                 from /mingw64/include/GL/freeglut.h:17,
                 from src/controls.cpp:1:
/usr/lib/gcc/x86_64-pc-msys/4.9.2/include/c++/bits/memoryfwd.h:63:3: error: template with C linkage
   template<typename>
   ^
/usr/lib/gcc/x86_64-pc-msys/4.9.2/include/c++/bits/memoryfwd.h:66:3: error: template specialization with C linkage
   template<>
   ^
/usr/lib/gcc/x86_64-pc-msys/4.9.2/include/c++/bits/memoryfwd.h:70:3: error: template with C linkage
   template<typename, typename>
   ^

...

In file included from /mingw64/include/GL/freeglut_std.h:143:0,
                 from /mingw64/include/GL/freeglut.h:17,
                 from src/controls.cpp:1:
/usr/include/w32api/GL/gl.h:684:1: error: ‘WINGDIAPI’ does not name a type
 WINGDIAPI void APIENTRY glAccum(GLenum op,GLfloat value);

...

/usr/include/w32api/GL/gl.h:1037:24: error: expected ‘)’ before ‘*’ token
 typedef void (APIENTRY *PFNGLGETCOLORTABLEPARAMETERFVEXTPROC)(GLenum target,GLenum pname,GLfloat *params);
                        ^
In file included from /mingw64/include/GL/freeglut_std.h:144:0,
                 from /mingw64/include/GL/freeglut.h:17,
                 from src/controls.cpp:1:
/usr/include/w32api/GL/glu.h:24:25: error: expected initializer before ‘gluErrorString’
 const GLubyte *APIENTRY gluErrorString(GLenum errCode);
                         ^
/usr/include/w32api/GL/glu.h:25:25: error: expected initializer before ‘gluErrorUnicodeStringEXT’
 const wchar_t *APIENTRY gluErrorUnicodeStringEXT(GLenum errCode);
                         ^

...

This is taken from just a partial log consisting of 4500 lines of errors. These are the most frequent ones repeated many times.

I previously thought that the problem lied in old MSYS/MinGW (not the MSYS2 port) which I tried first with the same results. However, MSYS2 did not solve the problems which makes me completely clueless since my code is written in C++ and it only requires standard C and C++ header files along with some GL ones. I do not use any extern "C" mangling.

Solution

  • The problem turned out not to be related to OpenGL, neither to MSYS(2)/MinGW(-w64) or MS Visual Studio 2013.

    For anyone who might be facing the same problems as I was, the vast majority of all the error reports was generated because there was a custom windows.h header file present in my project's include path. A header with the same name is present in standard Windows header library and is essential for proper functionality of other libraries.

    Lesson learned: never try to name a file with system-specific code after the operating system.