1 files changed, 75 insertions, 0 deletions
diff --git a/gfx/wr/webrender/tests/angle_shader_validation.rs b/gfx/wr/webrender/tests/angle_shader_validation.rs
new file mode 100644
index 0000000000..d6fe618de0
--- /dev/null
+++ b/gfx/wr/webrender/tests/angle_shader_validation.rs
@@ -0,0 +1,75 @@
+/* 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/. */
+
+extern crate mozangle;
+extern crate webrender;
+extern crate webrender_build;
+
+use mozangle::shaders::{BuiltInResources, Output, ShaderSpec, ShaderValidator};
+use webrender_build::shader::{ShaderFeatureFlags, ShaderVersion, build_shader_strings, get_shader_features};
+
+// from glslang
+const FRAGMENT_SHADER: u32 = 0x8B30;
+const VERTEX_SHADER: u32 = 0x8B31;
+
+#[test]
+fn validate_shaders() {
+    mozangle::shaders::initialize().unwrap();
+
+    let resources = BuiltInResources::default();
+    let vs_validator =
+        ShaderValidator::new(VERTEX_SHADER, ShaderSpec::Gles3, Output::Essl, &resources).unwrap();
+
+    let fs_validator =
+        ShaderValidator::new(FRAGMENT_SHADER, ShaderSpec::Gles3, Output::Essl, &resources).unwrap();
+
+    for (shader, configs) in get_shader_features(ShaderFeatureFlags::GLES) {
+        for config in configs {
+            let features = config.split(",").filter(|f| !f.is_empty()).collect::<Vec<_>>();
+
+            let (vs, fs) = build_shader_strings(
+                ShaderVersion::Gles,
+                &features,
+                shader,
+                &|f| webrender::get_unoptimized_shader_source(f, None)
+            );
+
+            let full_shader_name = format!("{} {}", shader, config);
+            validate(&vs_validator, &full_shader_name, vs);
+            validate(&fs_validator, &full_shader_name, fs);
+        }
+    }
+}
+
+fn validate(validator: &ShaderValidator, name: &str, source: String) {
+    // Check for each `switch` to have a `default`, see
+    // https://github.com/servo/webrender/wiki/Driver-issues#lack-of-default-case-in-a-switch
+    assert_eq!(source.matches("switch").count(), source.matches("default:").count(),
+        "Shader '{}' doesn't have all `switch` covered with `default` cases", name);
+    // Run Angle validator
+    match validator.compile_and_translate(&[&source]) {
+        Ok(_) => {
+            // Ensure that the shader uses at most 16 varying vectors. This counts the number of
+            // vectors assuming that the driver does not perform additional packing. The spec states
+            // that the driver should pack varyings, however, on some Adreno 3xx devices we have
+            // observed that this is not the case. See bug 1695912.
+            let varying_vectors = validator.get_num_unpacked_varying_vectors();
+            let max_varying_vectors = 16;
+            assert!(
+                varying_vectors <= max_varying_vectors,
+                "Shader {} uses {} varying vectors. Max allowed {}",
+                name, varying_vectors, max_varying_vectors
+            );
+
+            println!("Shader translated succesfully: {}", name);
+        }
+        Err(_) => {
+            panic!(
+                "Shader compilation failed: {}\n{}",
+                name,
+                validator.info_log()
+            );
+        }
+    }
+}