1// [config]
2// expect_result: fail
3// glsl_version: 4.20
4// require_extensions: GL_ARB_fragment_shader_interlock
5// check_link: false
6// [end config]
7
8/* The GL_ARB_fragment_shader_interlock spec says:
9 *
10 *    The beginInvocationInterlockARB() and endInvocationInterlockARB() may
11 *    only be placed inside the function main() of a fragment shader and may
12 *    not be called within any flow control.  These functions may not be
13 *    called after a return statement in the function main(), but may be
14 *    called after a discard statement.
15 *
16 * and
17 *
18 *    (8) What restrictions should be imposed on the use of the
19 *        beginInvocationInterlockARB() and endInvocationInterlockARB()
20 *        functions delimiting a critical section?
21 *
22 *      RESOLVED:  We impose restrictions similar to those on the barrier()
23 *      built-in function in tessellation control shaders to ensure that any
24 *      shader using this functionality has a single critical section that can
25 *      be easily identified during compilation...
26 *
27 * The GLSL 4.60 spec says:
28 *
29 *    For tessellation control shaders, the barrier() function may only be
30 *    placed inside the function main() of the tessellation control shader and
31 *    may not be called within any control flow. Barriers are also disallowed
32 *    after a return statement in the function main(). Any such misplaced
33 *    barriers result in a compile-time error.
34 *
35 * From this we infer that the first errors mentioned in the
36 * GL_ARB_fragment_shader_interlock spec are intended to generate compile-time
37 * errors.
38 */
39#version 420
40#extension GL_ARB_fragment_shader_interlock: require
41
42void wrapper()
43{
44	endInvocationInterlockARB();
45}
46
47void main()
48{
49	beginInvocationInterlockARB();
50	wrapper();
51}
52