From b453ba2c9f8ccb1d61a0ef50f0a40592df3366c3 Mon Sep 17 00:00:00 2001 From: Paul Berry Date: Thu, 11 Aug 2011 18:10:22 -0700 Subject: [PATCH] glsl: Make sure gl_ClipDistance and gl_ClipVertex are not both written. From section 7.1 (Vertex Shader Special Variables) of the GLSL 1.30 spec: "It is an error for a shader to statically write both gl_ClipVertex and gl_ClipDistance." Fixes piglit test mixing-clip-distance-and-clip-vertex-disallowed.c. Reviewed-by: Kenneth Graunke Reviewed-by: Ian Romanick --- src/glsl/linker.cpp | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+) diff --git a/src/glsl/linker.cpp b/src/glsl/linker.cpp index ba81c59ff2c..195f58f29c6 100644 --- a/src/glsl/linker.cpp +++ b/src/glsl/linker.cpp @@ -262,6 +262,25 @@ validate_vertex_shader_executable(struct gl_shader_program *prog, return false; } + if (prog->Version >= 130) { + /* From section 7.1 (Vertex Shader Special Variables) of the + * GLSL 1.30 spec: + * + * "It is an error for a shader to statically write both + * gl_ClipVertex and gl_ClipDistance." + */ + find_assignment_visitor clip_vertex("gl_ClipVertex"); + find_assignment_visitor clip_distance("gl_ClipDistance"); + + clip_vertex.run(shader->ir); + clip_distance.run(shader->ir); + if (clip_vertex.variable_found() && clip_distance.variable_found()) { + linker_error(prog, "vertex shader writes to both `gl_ClipVertex' " + "and `gl_ClipDistance'\n"); + return false; + } + } + return true; } -- 2.30.2