1 files changed, 65 insertions, 0 deletions
diff --git a/gfx/wr/wrench/src/test_shaders.rs b/gfx/wr/wrench/src/test_shaders.rs
new file mode 100644
index 0000000000..a2387c3ae9
--- /dev/null
+++ b/gfx/wr/wrench/src/test_shaders.rs
@@ -0,0 +1,65 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+use webrender::shader_source::OPTIMIZED_SHADERS;
+use glsl::parser::Parse as _;
+use glsl::syntax::{InterpolationQualifier, ShaderStage, SingleDeclaration};
+use glsl::syntax::{TypeSpecifierNonArray, TypeQualifierSpec};
+use glsl::visitor::{Host, Visit, Visitor};
+
+/// Tests that a shader contains no flat scalar varyings.
+/// These must be avoided on Adreno 3xx devices due to bug 1630356.
+fn test_no_flat_scalar_varyings(name: &str, shader: &mut ShaderStage) {
+    struct FlatScalarVaryingsVisitor {
+        shader_name: String,
+    }
+
+    impl Visitor for FlatScalarVaryingsVisitor {
+        fn visit_single_declaration(&mut self, declaration: &SingleDeclaration) -> Visit {
+            let is_scalar = matches!(declaration.ty.ty.ty,
+                TypeSpecifierNonArray::Bool
+                | TypeSpecifierNonArray::Int
+                | TypeSpecifierNonArray::UInt
+                | TypeSpecifierNonArray::Float
+                | TypeSpecifierNonArray::Double);
+
+            let qualifiers = declaration
+                .ty
+                .qualifier
+                .as_ref()
+                .map(|q| q.qualifiers.0.as_slice())
+                .unwrap_or(&[]);
+
+            let is_flat = qualifiers.contains(&TypeQualifierSpec::Interpolation(
+                InterpolationQualifier::Flat,
+            ));
+
+            assert!(
+                !(is_scalar && is_flat),
+                "{}: {} is a flat scalar varying",
+                self.shader_name,
+                &declaration.name.as_ref().unwrap()
+            );
+
+            Visit::Parent
+        }
+    }
+
+    let mut visitor = FlatScalarVaryingsVisitor {
+        shader_name: name.to_string(),
+    };
+    shader.visit(&mut visitor);
+}
+
+pub fn test_shaders() {
+    for ((_version, name), shader) in OPTIMIZED_SHADERS.iter() {
+        let mut vert = ShaderStage::parse(shader.vert_source).unwrap();
+        let mut frag = ShaderStage::parse(shader.frag_source).unwrap();
+
+        if cfg!(target_os = "android") {
+            test_no_flat_scalar_varyings(&format!("{}.vert", name), &mut vert);
+            test_no_flat_scalar_varyings(&format!("{}.frag", name), &mut frag);
+        }
+    }
+}