<html><body>Hello, just recently I encountered a problem when linking shaders, containing uniform consisting of anonymous structure. Here is the code of shaders, triggering the problem: //vertex shader uniform struct {vec3 a; vec3 b;} a; void main() { gl_Position = gl_ModelViewProjectionMatrix * gl_Vertex; } //fragment shader uniform struct {vec3 a; vec3 b;} a; void main() { gl_FragColor = vec4(1.0, 0.0, 0.0, 1.0); } The error message pops up when linking is performed: error: uniform `a' declared as type `#anon_struct_0002' and type `#anon_struct_0001' The problem is, that each anonymous structure gets its own unique type, without checking if such type already exists. It seems to me, that such code is somewhat in the gray area - the rest of OpenGL implementations doesn't seem to have a problem with this code (Intel on Win, OSX, Nvidia and AMD drivers in Win, OSX and Linux), which of course doesn't mean such a behavior is correct. I'd like to ask you, what is your take on this? Should anonymous structs be checked against ones seen already and the type name reused when suitable one is found? Thank you, Michal Navratil </body></html>