[Mesa-dev] [PATCH] glsl: Generate link error for non-matching gl_FragCoord redeclarations

[Anuj Phogat]

in different fragment shaders. This also applies to a case when gl_FragCoord
is redeclared with no layout qualifiers in one fragment shader and not
declared but used in other fragment shader.

Signed-off-by: Anuj Phogat <anuj.phogat at gmail.com>
Khronos Bug#12957
Cc: "10.5" <mesa-stable at lists.freedesktop.org>
Cc: Ian Romanick <idr at freedesktop.org>
---
 src/glsl/linker.cpp | 15 ++-------------
 1 file changed, 2 insertions(+), 13 deletions(-)

diff --git a/src/glsl/linker.cpp b/src/glsl/linker.cpp
index e11b6fa..e8bda4f 100644
--- a/src/glsl/linker.cpp
+++ b/src/glsl/linker.cpp
@@ -1365,24 +1365,13 @@ link_fs_input_layout_qualifiers(struct gl_shader_program *prog,
        *   "If gl_FragCoord is redeclared in any fragment shader in a program,
        *    it must be redeclared in all the fragment shaders in that program
        *    that have a static use gl_FragCoord."
-       *
-       * Exclude the case when one of the 'linked_shader' or 'shader' redeclares
-       * gl_FragCoord with no layout qualifiers but the other one doesn't
-       * redeclare it. If we strictly follow GLSL 1.50 spec's language, it
-       * should be a link error. But, generating link error for this case will
-       * be a wrong behaviour which spec didn't intend to do and it could also
-       * break some applications.
        */
       if ((linked_shader->redeclares_gl_fragcoord
            && !shader->redeclares_gl_fragcoord
-           && shader->uses_gl_fragcoord
-           && (linked_shader->origin_upper_left
-               || linked_shader->pixel_center_integer))
+           && shader->uses_gl_fragcoord)
           || (shader->redeclares_gl_fragcoord
               && !linked_shader->redeclares_gl_fragcoord
-              && linked_shader->uses_gl_fragcoord
-              && (shader->origin_upper_left
-                  || shader->pixel_center_integer))) {
+              && linked_shader->uses_gl_fragcoord)) {
              linker_error(prog, "fragment shader defined with conflicting "
                          "layout qualifiers for gl_FragCoord\n");
       }
-- 
1.9.3