Cygwin OpenGL compiling returns undefined references to imp_iob

Question

I'm attempting to compile this tutorial http://www.opengl-tutorial.org/beginners-tutorials/tutorial-1-opening-a-window/ with Cygwin. I'm getting the following errors:

$ g++ main.cpp -o main -lm -lgl -lglut -lglew -lglfw -lopengl32 -lglu32 -lglaux
 -lodbc32 -lodbccp32
/usr/lib/gcc/i686-pc-cygwin/4.7.3/../../../libglfw.a(win32_window.o):win32_windo
w.c:(.text+0x11a0): undefined reference to `_imp___iob'
/usr/lib/gcc/i686-pc-cygwin/4.7.3/../../../libglfw.a(win32_window.o):win32_windo
w.c:(.text+0x11c8): undefined reference to `_imp___iob'
/usr/lib/gcc/i686-pc-cygwin/4.7.3/../../../libglfw.a(win32_window.o):win32_windo
w.c:(.text+0x11f0): undefined reference to `_imp___iob'
/usr/lib/gcc/i686-pc-cygwin/4.7.3/../../../libglfw.a(win32_window.o):win32_windo
w.c:(.text+0x1394): undefined reference to `_imp___iob'
/usr/lib/gcc/i686-pc-cygwin/4.7.3/../../../libglfw.a(win32_window.o):win32_windo
w.c:(.text+0x1661): undefined reference to `_imp___iob'
/usr/lib/gcc/i686-pc-cygwin/4.7.3/../../../libglfw.a(win32_window.o):win32_windo
w.c:(.text+0x1696): more undefined references to `_imp___iob' follow
/usr/lib/gcc/i686-pc-cygwin/4.7.3/../../../../i686-pc-cygwin/bin/ld: /usr/lib/gc
c/i686-pc-cygwin/4.7.3/../../../libglfw.a(win32_window.o): bad reloc address 0x0
 in section `.rdata'
collect2: error: ld returned 1 exit status

What may be causing this?

Andon M. Coleman · Answer 1 · 2013-11-27T16:52:49.370

When you see unresolved symbols to _imp__, it implies you are trying to link against a library that was built to use a DLL at run-time. Technically, the problem is how the MSVC compiler mangles the import stub for __stdcall functions - it pre-fixes an underscore, which gcc is not expecting (e.g. _imp instead of imp).

cygwin/MinGW needs a little bit of extra help (either they must use a library that was compiled with gcc or the MSVC DLL-based import library must be altered). There is an article that explains this here.

However, the vast majority of the time the simpler solution is simply to link against the static linking version of your library. In the case of GLEW and glfw, they both ship with static libraries. You will need to define GLEW_STATIC and link against glew32s instead of glew. As for glfw, I am not as familiar - consult the documentation for glfw to find out how to do this.

Cygwin OpenGL compiling returns undefined references to imp_iob

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