[Mesa-dev] [PATCH] glsl: be more strict when validating shader inputs

[Ilia Mirkin]

interpolateAt* can only take input variables or an element of an input
variable array. No structs.

Further, GLSL 4.50 relaxes the requirement to allow swizzles, so enable
that as well.

This fixes the following dEQP tests:

dEQP-GLES31.functional.shaders.multisample_interpolation.interpolate_at_sample.negative.interpolate_struct_member
dEQP-GLES31.functional.shaders.multisample_interpolation.interpolate_at_centroid.negative.interpolate_struct_member
dEQP-GLES31.functional.shaders.multisample_interpolation.interpolate_at_offset.negative.interpolate_struct_member

Signed-off-by: Ilia Mirkin <imirkin at alum.mit.edu>
---
 src/compiler/glsl/ast_function.cpp | 26 ++++++++++++++++++--------
 1 file changed, 18 insertions(+), 8 deletions(-)

diff --git a/src/compiler/glsl/ast_function.cpp b/src/compiler/glsl/ast_function.cpp
index 4db3dd0..281735b 100644
--- a/src/compiler/glsl/ast_function.cpp
+++ b/src/compiler/glsl/ast_function.cpp
@@ -208,17 +208,27 @@ verify_parameter_modes(_mesa_glsl_parse_state *state,
 
       /* Verify that shader_in parameters are shader inputs */
       if (formal->data.must_be_shader_input) {
-         ir_variable *var = actual->variable_referenced();
-         if (!var || var->data.mode != ir_var_shader_in) {
-            _mesa_glsl_error(&loc, state,
-                             "parameter `%s` must be a shader input",
-                             formal->name);
-            return false;
+         const ir_rvalue *val = actual;
+
+         // GLSL 4.50 allows swizzles, while earlier GLSL versions do not.
+         if (val->ir_type == ir_type_swizzle) {
+            if (!state->is_version(450, 0)) {
+               _mesa_glsl_error(&loc, state,
+                                "parameter `%s` must not be swizzled",
+                                formal->name);
+               return false;
+            }
+            val = ((ir_swizzle *)val)->val;
+         }
+
+         while (val->ir_type == ir_type_dereference_array) {
+            val = ((ir_dereference_array *)val)->array;
          }
 
-         if (actual->ir_type == ir_type_swizzle) {
+         if (!val->as_dereference_variable() ||
+             val->variable_referenced()->data.mode != ir_var_shader_in) {
             _mesa_glsl_error(&loc, state,
-                             "parameter `%s` must not be swizzled",
+                             "parameter `%s` must be a shader input",
                              formal->name);
             return false;
          }
-- 
2.7.3