unittests: Add a position return value for vertex shaders

Fixes new validation errors added with:
https://dawn-review.googlesource.com/c/tint/+/48560

Change-Id: Icb9a3bc46574c365a812685d01aab336a11792c1
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/48681
Auto-Submit: Ben Clayton <bclayton@google.com>
Reviewed-by: Ryan Harrison <rharrison@chromium.org>
Reviewed-by: Austin Eng <enga@chromium.org>
Commit-Queue: Austin Eng <enga@chromium.org>

src/tests/unittests/validation/BindGroupValidationTests.cpp

@@ -1084,7 +1084,8 @@ class SetBindGroupValidationTest : public ValidationTest {
 
     wgpu::RenderPipeline CreateRenderPipeline() {
         wgpu::ShaderModule vsModule = utils::CreateShaderModule(device, R"(
-                [[stage(vertex)]] fn main() {
+                [[stage(vertex)]] fn main() -> [[builtin(position)]] vec4<f32> {
+                    return vec4<f32>();
                 })");
 
         wgpu::ShaderModule fsModule = utils::CreateShaderModule(device, R"(
@@ -1487,7 +1488,8 @@ class SetBindGroupPersistenceValidationTest : public ValidationTest {
         ValidationTest::SetUp();
 
         mVsModule = utils::CreateShaderModule(device, R"(
-                [[stage(vertex)]] fn main() {
+                [[stage(vertex)]] fn main() -> [[builtin(position)]] vec4<f32> {
+                    return vec4<f32>();
                 })");
     }
 
@@ -1689,7 +1691,8 @@ class BindGroupLayoutCompatibilityTest : public ValidationTest {
         const char* fsShader,
         std::vector<wgpu::BindGroupLayout> bindGroupLayout) {
         wgpu::ShaderModule vsModule = utils::CreateShaderModule(device, R"(
-                [[stage(vertex)]] fn main() {
+                [[stage(vertex)]] fn main() -> [[builtin(position)]] vec4<f32> {
+                    return vec4<f32>();
                 })");
 
         wgpu::ShaderModule fsModule = utils::CreateShaderModule(device, fsShader);
@@ -2061,7 +2064,8 @@ class ComparisonSamplerBindingTest : public ValidationTest {
     wgpu::RenderPipeline CreateFragmentPipeline(wgpu::BindGroupLayout* bindGroupLayout,
                                                 const char* fragmentSource) {
         wgpu::ShaderModule vsModule = utils::CreateShaderModule(device, R"(
-            [[stage(vertex)]] fn main() {
+            [[stage(vertex)]] fn main() -> [[builtin(position)]] vec4<f32> {
+                return vec4<f32>();
             })");
 
         wgpu::ShaderModule fsModule = utils::CreateShaderModule(device, fragmentSource);

src/tests/unittests/validation/GetBindGroupLayoutValidationTests.cpp

@@ -21,7 +21,8 @@ class GetBindGroupLayoutTests : public ValidationTest {
   protected:
     wgpu::RenderPipeline RenderPipelineFromFragmentShader(const char* shader) {
         wgpu::ShaderModule vsModule = utils::CreateShaderModule(device, R"(
-                [[stage(vertex)]] fn main() {
+                [[stage(vertex)]] fn main() -> [[builtin(position)]] vec4<f32> {
+                    return vec4<f32>();
                 })");
 
         wgpu::ShaderModule fsModule = utils::CreateShaderModule(device, shader);
@@ -50,9 +51,10 @@ TEST_F(GetBindGroupLayoutTests, SameObject) {
         [[group(0), binding(0)]] var<uniform> uniform0 : S;
         [[group(1), binding(0)]] var<uniform> uniform1 : S;
 
-        [[stage(vertex)]] fn main() {
+        [[stage(vertex)]] fn main() -> [[builtin(position)]] vec4<f32> {
             var pos : vec4<f32> = uniform0.pos;
             pos = uniform1.pos;
+            return vec4<f32>();
         })");
 
     wgpu::ShaderModule fsModule = utils::CreateShaderModule(device, R"(
@@ -473,9 +475,10 @@ TEST_F(GetBindGroupLayoutTests, DuplicateBinding) {
         [[group(0), binding(0)]] var<uniform> uniform0 : S;
         [[group(1), binding(0)]] var<uniform> uniform1 : S;
 
-        [[stage(vertex)]] fn main() {
+        [[stage(vertex)]] fn main() -> [[builtin(position)]] vec4<f32> {
             var pos : vec4<f32> = uniform0.pos;
             pos = uniform1.pos;
+            return vec4<f32>();
         })");
 
     wgpu::ShaderModule fsModule = utils::CreateShaderModule(device, R"(
@@ -509,8 +512,9 @@ TEST_F(GetBindGroupLayoutTests, MinBufferSize) {
         };
         [[group(0), binding(0)]] var<uniform> uniforms : S;
 
-        [[stage(vertex)]] fn main() {
+        [[stage(vertex)]] fn main() -> [[builtin(position)]] vec4<f32> {
             var pos : f32 = uniforms.pos;
+            return vec4<f32>();
         })");
 
     wgpu::ShaderModule vsModule64 = utils::CreateShaderModule(device, R"(
@@ -519,8 +523,9 @@ TEST_F(GetBindGroupLayoutTests, MinBufferSize) {
         };
         [[group(0), binding(0)]] var<uniform> uniforms : S;
 
-        [[stage(vertex)]] fn main() {
+        [[stage(vertex)]] fn main() -> [[builtin(position)]] vec4<f32> {
             var pos : mat4x4<f32> = uniforms.pos;
+            return vec4<f32>();
         })");
 
     wgpu::ShaderModule fsModule4 = utils::CreateShaderModule(device, R"(
@@ -594,13 +599,15 @@ TEST_F(GetBindGroupLayoutTests, StageAggregation) {
     DAWN_SKIP_TEST_IF(UsesWire());
 
     wgpu::ShaderModule vsModuleNoSampler = utils::CreateShaderModule(device, R"(
-        [[stage(vertex)]] fn main() {
+        [[stage(vertex)]] fn main() -> [[builtin(position)]] vec4<f32> {
+            return vec4<f32>();
         })");
 
     wgpu::ShaderModule vsModuleSampler = utils::CreateShaderModule(device, R"(
         [[group(0), binding(0)]] var mySampler: sampler;
-        [[stage(vertex)]] fn main() {
+        [[stage(vertex)]] fn main() -> [[builtin(position)]] vec4<f32> {
             let s : sampler = mySampler;
+            return vec4<f32>();
         })");
 
     wgpu::ShaderModule fsModuleNoSampler = utils::CreateShaderModule(device, R"(
@@ -664,8 +671,9 @@ TEST_F(GetBindGroupLayoutTests, ConflictingBindingType) {
         };
         [[group(0), binding(0)]] var<uniform> ubo : S;
 
-        [[stage(vertex)]] fn main() {
+        [[stage(vertex)]] fn main() -> [[builtin(position)]] vec4<f32> {
             var pos : vec4<f32> = ubo.pos;
+            return vec4<f32>();
         })");
 
     wgpu::ShaderModule fsModule = utils::CreateShaderModule(device, R"(
@@ -691,8 +699,9 @@ TEST_F(GetBindGroupLayoutTests, ConflictingBindingTextureMultisampling) {
     wgpu::ShaderModule vsModule = utils::CreateShaderModule(device, R"(
         [[group(0), binding(0)]] var myTexture : texture_2d<f32>;
 
-        [[stage(vertex)]] fn main() {
+        [[stage(vertex)]] fn main() -> [[builtin(position)]] vec4<f32> {
             textureDimensions(myTexture);
+            return vec4<f32>();
         })");
 
     wgpu::ShaderModule fsModule = utils::CreateShaderModule(device, R"(
@@ -715,8 +724,9 @@ TEST_F(GetBindGroupLayoutTests, ConflictingBindingViewDimension) {
     wgpu::ShaderModule vsModule = utils::CreateShaderModule(device, R"(
         [[group(0), binding(0)]] var myTexture : texture_2d<f32>;
 
-        [[stage(vertex)]] fn main() {
+        [[stage(vertex)]] fn main() -> [[builtin(position)]] vec4<f32> {
             textureDimensions(myTexture);
+            return vec4<f32>();
         })");
 
     wgpu::ShaderModule fsModule = utils::CreateShaderModule(device, R"(
@@ -739,8 +749,9 @@ TEST_F(GetBindGroupLayoutTests, ConflictingBindingTextureComponentType) {
     wgpu::ShaderModule vsModule = utils::CreateShaderModule(device, R"(
         [[group(0), binding(0)]] var myTexture : texture_2d<f32>;
 
-        [[stage(vertex)]] fn main() {
+        [[stage(vertex)]] fn main() -> [[builtin(position)]] vec4<f32> {
             textureDimensions(myTexture);
+            return vec4<f32>();
         })");
 
     wgpu::ShaderModule fsModule = utils::CreateShaderModule(device, R"(
@@ -833,8 +844,9 @@ TEST_F(GetBindGroupLayoutTests, Reflection) {
         };
         [[group(0), binding(0)]] var<uniform> uniforms : S;
 
-        [[stage(vertex)]] fn main() {
+        [[stage(vertex)]] fn main() -> [[builtin(position)]] vec4<f32> {
             var pos : vec4<f32> = uniforms.pos;
+            return vec4<f32>();
         })");
 
     wgpu::ShaderModule fsModule = utils::CreateShaderModule(device, R"(

src/tests/unittests/validation/MinimumBufferSizeValidationTests.cpp

@@ -123,8 +123,10 @@ namespace {
 
     // Creates a vertex shader with given bindings
     std::string CreateVertexShaderWithBindings(const std::vector<BindingDescriptor>& bindings) {
-        return kStructs + GenerateBindingString(bindings) + "[[stage(vertex)]] fn main() {\n" +
+        return kStructs + GenerateBindingString(bindings) +
-               GenerateReferenceString(bindings, wgpu::ShaderStage::Vertex) + "}";
+               "[[stage(vertex)]] fn main() -> [[builtin(position)]] vec4<f32> {\n" +
+               GenerateReferenceString(bindings, wgpu::ShaderStage::Vertex) +
+               "\n   return vec4<f32>(); " + "}";
     }
 
     // Creates a fragment shader with given bindings

src/tests/unittests/validation/RenderBundleValidationTests.cpp

@@ -33,7 +33,8 @@ namespace {
                 };
                 [[group(0), binding(0)]] var<uniform> uniforms : S;
 
-                [[stage(vertex)]] fn main([[location(0)]] pos : vec2<f32>) {
+                [[stage(vertex)]] fn main([[location(0)]] pos : vec2<f32>) -> [[builtin(position)]] vec4<f32> {
+                    return vec4<f32>();
                 })");
 
             fsModule = utils::CreateShaderModule(device, R"(

src/tests/unittests/validation/RenderPipelineValidationTests.cpp

@@ -486,8 +486,9 @@ TEST_F(RenderPipelineValidationTest, StorageBufferInVertexShaderNoLayout) {
             data : array<u32, 100>;
         };
         [[group(0), binding(0)]] var<storage> dst : [[access(read_write)]] Dst;
-        [[stage(vertex)]] fn main([[builtin(vertex_index)]] VertexIndex : u32) {
+        [[stage(vertex)]] fn main([[builtin(vertex_index)]] VertexIndex : u32) -> [[builtin(position)]] vec4<f32> {
             dst.data[VertexIndex] = 0x1234u;
+            return vec4<f32>();
         })");
 
     utils::ComboRenderPipelineDescriptor2 descriptor;

src/tests/unittests/validation/ResourceUsageTrackingTests.cpp

@@ -47,7 +47,8 @@ namespace {
         // pipeline. But those bind groups in caller can be used for validation for other purposes.
         wgpu::RenderPipeline CreateNoOpRenderPipeline() {
             wgpu::ShaderModule vsModule = utils::CreateShaderModule(device, R"(
-                [[stage(vertex)]] fn main() {
+                [[stage(vertex)]] fn main() -> [[builtin(position)]] vec4<f32> {
+                    return vec4<f32>();
                 })");
 
             wgpu::ShaderModule fsModule = utils::CreateShaderModule(device, R"(
@@ -772,7 +773,8 @@ namespace {
 
             // Create a passthrough render pipeline with a readonly buffer
             wgpu::ShaderModule vsModule = utils::CreateShaderModule(device, R"(
-                [[stage(vertex)]] fn main() {
+                [[stage(vertex)]] fn main() -> [[builtin(position)]] vec4<f32> {
+                    return vec4<f32>();
                 })");
 
             wgpu::ShaderModule fsModule = utils::CreateShaderModule(device, R"(
@@ -1550,7 +1552,8 @@ namespace {
         {
             // Create a passthrough render pipeline with a readonly storage texture
             wgpu::ShaderModule vsModule = utils::CreateShaderModule(device, R"(
-                [[stage(vertex)]] fn main() {
+                [[stage(vertex)]] fn main() -> [[builtin(position)]] vec4<f32> {
+                    return vec4<f32>();
                 })");
 
             wgpu::ShaderModule fsModule = utils::CreateShaderModule(device, R"(

src/tests/unittests/validation/UnsafeAPIValidationTests.cpp

@@ -65,7 +65,11 @@ TEST_F(UnsafeAPIValidationTest, DrawIndexedIndirectDisallowed) {
     bundleDesc.cColorFormats[0] = renderPass.attachmentFormat;
 
     utils::ComboRenderPipelineDescriptor2 desc;
-    desc.vertex.module = utils::CreateShaderModule(device, "[[stage(vertex)]] fn main() {}");
+    desc.vertex.module = utils::CreateShaderModule(
+        device,
+        R"([[stage(vertex)]] fn main() -> [[builtin(position)]] vec4<f32> {
+            return vec4<f32>();
+        })");
     desc.cFragment.module = utils::CreateShaderModule(device, "[[stage(fragment)]] fn main() {}");
     wgpu::RenderPipeline pipeline = device.CreateRenderPipeline2(&desc);