Undefined GLEXT symbols when compiling

[pzl]

Problem:

on recent Arch linux, this isn't compiling as-is. Basically problem finding the symbol definition of GLintptr (error: unknown type name 'GLintptr'). Googling this found a similar problem filed on libreoffice. That ticket pointed to GL_GLEXT_LEGACY being defined, having an effect on all this. And in this project, in src/sdDefs.h it is defined for non-windows, non-apple platforms.

Steps to reproduce:

sh autogen.sh
./configure
make

Platform info (I don't know what's relevant):

GLX version: 1.4
GL_GLEXT_VERSION (found in /usr/include/glext.h): 20140810
OpenGL version string: 4.4.0 NVIDIA 343.22
Kernel: 3.17.1

Full error:

make  all-recursive
make[1]: Entering directory '/home/dan/tmp/ShivaVG'
Making all in src
make[2]: Entering directory '/home/dan/tmp/ShivaVG/src'
/bin/sh ../libtool  --tag=CC   --mode=compile gcc -DHAVE_CONFIG_H -I. -I..    -ansi -pedantic -I../include/vg -INONE/include -MT libOpenVG_la-shExtensions.lo -MD -MP -MF .deps/libOpenVG_la-shExtensions.Tpo -c -o libOpenVG_la-shExtensions.lo `test -f 'shExtensions.c' || echo './'`shExtensions.c
libtool: compile:  gcc -DHAVE_CONFIG_H -I. -I.. -ansi -pedantic -I../include/vg -INONE/include -MT libOpenVG_la-shExtensions.lo -MD -MP -MF .deps/libOpenVG_la-shExtensions.Tpo -c shExtensions.c  -fPIC -DPIC -o .libs/libOpenVG_la-shExtensions.o
In file included from /usr/include/GL/glx.h:333:0,
                 from shDefs.h:170,
                 from shExtensions.c:23:
/usr/include/GL/glxext.h:480:143: error: unknown type name 'GLintptr'
 typedef void ( *PFNGLXCOPYBUFFERSUBDATANVPROC) (Display *dpy, GLXContext readCtx, GLXContext writeCtx, GLenum readTarget, GLenum writeTarget, GLintptr readOffset, GLintptr writeOffset, GLsizeiptr size);
                                                                                                                                               ^
/usr/include/GL/glxext.h:480:164: error: unknown type name 'GLintptr'
 typedef void ( *PFNGLXCOPYBUFFERSUBDATANVPROC) (Display *dpy, GLXContext readCtx, GLXContext writeCtx, GLenum readTarget, GLenum writeTarget, GLintptr readOffset, GLintptr writeOffset, GLsizeiptr size);
                                                                                                                                                                    ^
/usr/include/GL/glxext.h:480:186: error: unknown type name 'GLsizeiptr'
 typedef void ( *PFNGLXCOPYBUFFERSUBDATANVPROC) (Display *dpy, GLXContext readCtx, GLXContext writeCtx, GLenum readTarget, GLenum writeTarget, GLintptr readOffset, GLintptr writeOffset, GLsizeiptr size);
                                                                                                                                                                                          ^
/usr/include/GL/glxext.h:481:148: error: unknown type name 'GLintptr'
 typedef void ( *PFNGLXNAMEDCOPYBUFFERSUBDATANVPROC) (Display *dpy, GLXContext readCtx, GLXContext writeCtx, GLuint readBuffer, GLuint writeBuffer, GLintptr readOffset, GLintptr writeOffset, GLsizeiptr size);
                                                                                                                                                    ^
/usr/include/GL/glxext.h:481:169: error: unknown type name 'GLintptr'
 typedef void ( *PFNGLXNAMEDCOPYBUFFERSUBDATANVPROC) (Display *dpy, GLXContext readCtx, GLXContext writeCtx, GLuint readBuffer, GLuint writeBuffer, GLintptr readOffset, GLintptr writeOffset, GLsizeiptr size);
                                                                                                                                                                         ^
/usr/include/GL/glxext.h:481:191: error: unknown type name 'GLsizeiptr'
 typedef void ( *PFNGLXNAMEDCOPYBUFFERSUBDATANVPROC) (Display *dpy, GLXContext readCtx, GLXContext writeCtx, GLuint readBuffer, GLuint writeBuffer, GLintptr readOffset, GLintptr writeOffset, GLsizeiptr size);
                                                                                                                                                                                               ^
Makefile:459: recipe for target 'libOpenVG_la-shExtensions.lo' failed
make[2]: *** [libOpenVG_la-shExtensions.lo] Error 1
make[2]: Leaving directory '/home/dan/tmp/ShivaVG/src'
Makefile:393: recipe for target 'all-recursive' failed
make[1]: *** [all-recursive] Error 1
make[1]: Leaving directory '/home/dan/tmp/ShivaVG'
Makefile:324: recipe for target 'all' failed
make: *** [all] Error 2

Fix (for me at least, not sure if this is a total fix)

diff --git a/src/shDefs.h b/src/shDefs.h
index 502ee30..dea34bf 100644
--- a/src/shDefs.h
+++ b/src/shDefs.h
@@ -166,6 +166,7 @@ SHfloat getMaxFloat();
 #else
 #  define GL_GLEXT_LEGACY /* don't include glext.h */
 #  include <GL/gl.h>
+#  include <GL/glext.h>
 #  include <GL/glu.h>
 #  include <GL/glx.h>
 #endif

I'd issue a PR with this, but the comment above it literally says not to do this. So I'm not sure if this should be the permanent fix.

Huh, it explicitly says /* don't include glext.h */ but without glext.h it doesn't compiles under linux indeed. I wonder what was the reason behind this comment.

Ok, here's the real fix:

#else
#  include <GL/gl.h>
#  include <GL/glu.h>
#  define GL_GLEXT_LEGACY /* don't include glext.h */
#  include <GL/glx.h>
#endif

The original developer placed definition on the wrong line, you should define it just after glx.h inclusion.