Make usage of overridable constants a validation error

This feature is not yet implemented in Tint and it not planned for OT.

BUG=dawn:799

Change-Id: Ib97dcd39e8ae956aa6fdc4cc1b148ec7f101b061
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/54280
Commit-Queue: Ryan Harrison <rharrison@chromium.org>
Reviewed-by: Corentin Wallez <cwallez@chromium.org>

src/dawn_native/ShaderModule.cpp

@@ -886,6 +886,11 @@ namespace dawn_native {
             for (auto& entryPoint : entryPoints) {
                 ASSERT(result.count(entryPoint.name) == 0);
 
+                if (!entryPoint.overridable_constants.empty()) {
+                    return DAWN_VALIDATION_ERROR(
+                        "Pipeline overridable constants are not implemented yet");
+                }
+
                 auto metadata = std::make_unique<EntryPointMetadata>();
 
                 DAWN_TRY_ASSIGN(metadata->stage, TintPipelineStageToShaderStage(entryPoint.stage));

src/tests/end2end/ShaderTests.cpp

@@ -305,6 +305,23 @@ fn fragmentMain(input : VertexOut) -> [[location(0)]] vec4<f32> {
     wgpu::RenderPipeline pipeline = device.CreateRenderPipeline(&rpDesc);
 }
 
+// Feature currently not implemented in Tint, so should fail validation.
+TEST_P(ShaderTests, PipelineOverridableUsed) {
+    DAWN_TEST_UNSUPPORTED_IF(HasToggleEnabled("skip_validation"));
+    DAWN_TEST_UNSUPPORTED_IF(!HasToggleEnabled("use_tint_generator"));
+
+    std::string shader = R"(
+[[override]] let foo : f32;
+
+[[stage(compute)]]
+fn ep_func() {
+  var local_foo : f32;
+  local_foo = foo;
+  return;
+})";
+    ASSERT_DEVICE_ERROR(utils::CreateShaderModule(device, shader.c_str()));
+}
+
 DAWN_INSTANTIATE_TEST(ShaderTests,
                       D3D12Backend(),
                       MetalBackend(),