QT_NO_OPENGL must not be defined when running clangqdoc
because there are opengl elements that must be documented.
That means clang will see uses of GLxxx, which might not
be included on some platforms. For example, clang must
parse the declaration for class QOpenGLFramebufferObject,
which uses GLuint, GLenum, and GLbitfield, because there
is documentation to be published for that class in
qopenglframebufferobject.cpp.
This change uses Q_CLANG_QDOC to first undef the needed
GLxxx types and then provide suitable typedefs for them.
This technique is also used in qglshader.h.
This works for macOS, but is it the right way to solve the
problem?
This change also removes some \overload commands, because
they shouldn't be used on constructors. And some \fn commands
that are made unnecessary by upgrading to clang.
Change-Id: I4ac658e951b3f2011698005f0238d4dea85fc403
Reviewed-by: Martin Smith <martin.smith@qt.io>
f4ad5ede58