From a751adf07117ec4b3659fe60d0a833ebfcd4f840 Mon Sep 17 00:00:00 2001 From: Anuj Phogat Date: Thu, 20 Feb 2014 18:32:25 -0800 Subject: [PATCH] glsl: Compile error if fs uses gl_FragCoord before first redeclaration Section 4.3.8.1, page 39 of GLSL 1.50 spec says: "Within any shader, the first redeclarations of gl_FragCoord must appear before any use of gl_FragCoord." GLSL compiler should generate an error in following case: vec4 p = gl_FragCoord; layout(origin_upper_left) in vec4 gl_FragCoord; void main() { } Signed-off-by: Anuj Phogat Cc: Reviewed-by: Ian Romanick --- src/glsl/ast_to_hir.cpp | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) diff --git a/src/glsl/ast_to_hir.cpp b/src/glsl/ast_to_hir.cpp index 35220dd8cf5..f257a248680 100644 --- a/src/glsl/ast_to_hir.cpp +++ b/src/glsl/ast_to_hir.cpp @@ -2535,6 +2535,23 @@ apply_type_qualifier_to_variable(const struct ast_type_qualifier *qual, if (var->name != NULL && strcmp(var->name, "gl_FragCoord") == 0) { + /* Section 4.3.8.1, page 39 of GLSL 1.50 spec says: + * + * "Within any shader, the first redeclarations of gl_FragCoord + * must appear before any use of gl_FragCoord." + * + * Generate a compiler error if above condition is not met by the + * fragment shader. + */ + ir_variable *earlier = state->symbols->get_variable("gl_FragCoord"); + if (earlier != NULL && + earlier->data.used && + !state->fs_redeclares_gl_fragcoord) { + _mesa_glsl_error(loc, state, + "gl_FragCoord used before its first redeclaration " + "in fragment shader"); + } + /* Make sure all gl_FragCoord redeclarations specify the same layout * qualifiers. */ -- 2.30.2