tint/renamer: Preserve diagnostic control names

Add a Dawn E2E test to make sure that diagnostic controls work through
the whole shader compilation flow.

Bug: tint:1809
Fixed: chromium:1410930
Change-Id: Icea31cfadbbc182008a8a07efcddb402954dd1c7
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/117980
Kokoro: Kokoro <noreply+kokoro@google.com>
Reviewed-by: Ben Clayton <bclayton@google.com>
Commit-Queue: James Price <jrprice@google.com>

src/dawn/tests/end2end/ShaderTests.cpp

@@ -1372,6 +1372,57 @@ struct ShaderIO {
     EXPECT_PIXEL_RGBA8_EQ(utils::RGBA8(0, 255, 102, 255), renderPass.color, 0, 0);
 }
 
+// Test that the derivative_uniformity diagnostic filter is handled correctly through the full
+// shader compilation flow.
+TEST_P(ShaderTests, DerivativeUniformityDiagnosticFilter) {
+    wgpu::ShaderModule vsModule = utils::CreateShaderModule(device, R"(
+struct VertexOut {
+  @builtin(position) pos : vec4<f32>,
+  @location(0) value : f32,
+}
+
+@vertex
+fn main(@builtin(vertex_index) VertexIndex : u32) -> VertexOut {
+  const pos = array(
+      vec2( 1.0, -1.0),
+      vec2(-1.0, -1.0),
+      vec2( 0.0,  1.0),
+  );
+  return VertexOut(vec4(pos[VertexIndex], 0.0, 1.0), 0.5);
+})");
+
+    wgpu::ShaderModule fsModule = utils::CreateShaderModule(device, R"(
+diagnostic(off, derivative_uniformity);
+
+@fragment
+fn main(@location(0) value : f32) -> @location(0) vec4<f32> {
+  if (value > 0) {
+    let intensity = 1.0 - dpdx(1.0);
+    return vec4(intensity, intensity, intensity, 1.0);
+  }
+  return vec4(1.0);
+})");
+
+    utils::BasicRenderPass renderPass = utils::CreateBasicRenderPass(device, 1, 1);
+
+    utils::ComboRenderPipelineDescriptor descriptor;
+    descriptor.vertex.module = vsModule;
+    descriptor.cFragment.module = fsModule;
+    descriptor.primitive.topology = wgpu::PrimitiveTopology::TriangleList;
+    descriptor.cTargets[0].format = renderPass.colorFormat;
+    wgpu::RenderPipeline pipeline = device.CreateRenderPipeline(&descriptor);
+
+    wgpu::CommandEncoder encoder = device.CreateCommandEncoder();
+    wgpu::RenderPassEncoder pass = encoder.BeginRenderPass(&renderPass.renderPassInfo);
+    pass.SetPipeline(pipeline);
+    pass.Draw(3);
+    pass.End();
+    wgpu::CommandBuffer commands = encoder.Finish();
+    queue.Submit(1, &commands);
+
+    EXPECT_PIXEL_RGBA8_EQ(utils::RGBA8(255, 255, 255, 255), renderPass.color, 0, 0);
+}
+
 DAWN_INSTANTIATE_TEST(ShaderTests,
                       D3D12Backend(),
                       D3D12Backend({"use_dxc"}),

src/tint/transform/renamer.cc

@@ -1313,6 +1313,9 @@ Transform::ApplyResult Renamer::Apply(const Program* src,
                         });
                 }
             },
+            [&](const ast::DiagnosticControl* diagnostic) {
+                preserved_identifiers.Add(diagnostic->rule_name);
+            },
             [&](const ast::TypeName* type_name) {
                 if (is_type_short_name(type_name->name)) {
                     preserved_type_names.Add(type_name);

src/tint/transform/renamer_test.cc

@@ -189,6 +189,48 @@ fn tint_symbol() {
     EXPECT_THAT(data->remappings, ContainerEq(expected_remappings));
 }
 
+TEST_F(RenamerTest, PreserveDiagnosticControls) {
+    auto* src = R"(
+diagnostic(off, unreachable_code);
+
+@diagnostic(off, derivative_uniformity)
+@fragment
+fn entry(@location(0) value : f32) -> @location(0) f32 {
+  if (value > 0) {
+    return dpdx(value);
+    return 0.0;
+  }
+  return 1.0;
+}
+)";
+
+    auto* expect = R"(
+diagnostic(off, unreachable_code);
+
+@diagnostic(off, derivative_uniformity) @fragment
+fn tint_symbol(@location(0) tint_symbol_1 : f32) -> @location(0) f32 {
+  if ((tint_symbol_1 > 0)) {
+    return dpdx(tint_symbol_1);
+    return 0.0;
+  }
+  return 1.0;
+}
+)";
+
+    auto got = Run<Renamer>(src);
+
+    EXPECT_EQ(expect, str(got));
+
+    auto* data = got.data.Get<Renamer::Data>();
+
+    ASSERT_NE(data, nullptr);
+    Renamer::Data::Remappings expected_remappings = {
+        {"entry", "tint_symbol"},
+        {"value", "tint_symbol_1"},
+    };
+    EXPECT_THAT(data->remappings, ContainerEq(expected_remappings));
+}
+
 TEST_F(RenamerTest, PreserveUnicode) {
     auto src = R"(
 @fragment