src/tests/end2end/ShaderTests.cpp - dawn - Git at Google

 // Copyright 2021 The Dawn Authors
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
 // You may obtain a copy of the License at
 //
 //     http://www.apache.org/licenses/LICENSE-2.0
 //
 // Unless required by applicable law or agreed to in writing, software
 // distributed under the License is distributed on an "AS IS" BASIS,
 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 // See the License for the specific language governing permissions and
 // limitations under the License.

 #include "tests/DawnTest.h"

 #include "utils/ComboRenderPipelineDescriptor.h"
 #include "utils/WGPUHelpers.h"

 #include <vector>

 class ShaderTests : public DawnTest {};

 // Test that log2 is being properly calculated, base on crbug.com/1046622
 TEST_P(ShaderTests, ComputeLog2) {
     uint32_t const kSteps = 19;
     std::vector<uint32_t> data(kSteps, 0);
     std::vector<uint32_t> expected{0, 1, 1, 2, 2, 3, 3, 4, 4, 5, 5, 6, 6, 7, 7, 8, 8, 9, 32};
     uint64_t bufferSize = static_cast<uint64_t>(data.size() * sizeof(uint32_t));
     wgpu::Buffer buffer = utils::CreateBufferFromData(
         device, data.data(), bufferSize, wgpu::BufferUsage::Storage | wgpu::BufferUsage::CopySrc);

     std::string shader = R"(
 [[block]] struct Buf {
     data : array<u32, 19>;
 };

 [[group(0), binding(0)]] var<storage> buf : [[access(read_write)]] Buf;

 [[stage(compute)]] fn main() {
     let factor : f32 = 1.0001;

     buf.data[0] = u32(log2(1.0 * factor));
     buf.data[1] = u32(log2(2.0 * factor));
     buf.data[2] = u32(log2(3.0 * factor));
     buf.data[3] = u32(log2(4.0 * factor));
     buf.data[4] = u32(log2(7.0 * factor));
     buf.data[5] = u32(log2(8.0 * factor));
     buf.data[6] = u32(log2(15.0 * factor));
     buf.data[7] = u32(log2(16.0 * factor));
     buf.data[8] = u32(log2(31.0 * factor));
     buf.data[9] = u32(log2(32.0 * factor));
     buf.data[10] = u32(log2(63.0 * factor));
     buf.data[11] = u32(log2(64.0 * factor));
     buf.data[12] = u32(log2(127.0 * factor));
     buf.data[13] = u32(log2(128.0 * factor));
     buf.data[14] = u32(log2(255.0 * factor));
     buf.data[15] = u32(log2(256.0 * factor));
     buf.data[16] = u32(log2(511.0 * factor));
     buf.data[17] = u32(log2(512.0 * factor));
     buf.data[18] = u32(log2(4294967295.0 * factor));
 })";

     wgpu::ComputePipelineDescriptor csDesc;
     csDesc.computeStage.module = utils::CreateShaderModule(device, shader.c_str());
     csDesc.computeStage.entryPoint = "main";
     wgpu::ComputePipeline pipeline = device.CreateComputePipeline(&csDesc);

     wgpu::BindGroup bindGroup =
         utils::MakeBindGroup(device, pipeline.GetBindGroupLayout(0), {{0, buffer}});

     wgpu::CommandBuffer commands;
     {
         wgpu::CommandEncoder encoder = device.CreateCommandEncoder();
         wgpu::ComputePassEncoder pass = encoder.BeginComputePass();
         pass.SetPipeline(pipeline);
         pass.SetBindGroup(0, bindGroup);
         pass.Dispatch(1);
         pass.EndPass();

         commands = encoder.Finish();
     }

     queue.Submit(1, &commands);

     EXPECT_BUFFER_U32_RANGE_EQ(expected.data(), buffer, 0, kSteps);
 }

 TEST_P(ShaderTests, BadWGSL) {
     DAWN_SKIP_TEST_IF(HasToggleEnabled("skip_validation"));

     std::string shader = R"(
 I am an invalid shader and should never pass validation!
 })";
     ASSERT_DEVICE_ERROR(utils::CreateShaderModule(device, shader.c_str()));
 }

 // Tests that shaders using non-struct function parameters and return values for shader stage I/O
 // can compile and link successfully.
 TEST_P(ShaderTests, WGSLParamIO) {
     std::string vertexShader = R"(
 [[stage(vertex)]]
 fn main([[builtin(vertex_index)]] VertexIndex : u32) -> [[builtin(position)]] vec4<f32> {
     let pos : array<vec2<f32>, 3> = array<vec2<f32>, 3>(
         vec2<f32>(-1.0,  1.0),
         vec2<f32>( 1.0,  1.0),
         vec2<f32>( 0.0, -1.0));
     return vec4<f32>(pos[VertexIndex], 0.0, 1.0);
 })";
     wgpu::ShaderModule vsModule = utils::CreateShaderModule(device, vertexShader.c_str());

     std::string fragmentShader = R"(
 [[stage(fragment)]]
 fn main([[builtin(position)]] fragCoord : vec4<f32>) -> [[location(0)]] vec4<f32> {
     return vec4<f32>(fragCoord.xy, 0.0, 1.0);
 })";
     wgpu::ShaderModule fsModule = utils::CreateShaderModule(device, fragmentShader.c_str());

     utils::ComboRenderPipelineDescriptor rpDesc;
     rpDesc.vertex.module = vsModule;
     rpDesc.cFragment.module = fsModule;
     wgpu::RenderPipeline pipeline = device.CreateRenderPipeline(&rpDesc);
 }

 // Tests that a vertex shader using struct function parameters and return values for shader stage
 // I/O can compile and link successfully against a fragement shader using compatible non-struct I/O.
 TEST_P(ShaderTests, WGSLMixedStructParamIO) {
     std::string vertexShader = R"(
 struct VertexIn {
     [[location(0)]] position : vec3<f32>;
     [[location(1)]] color : vec4<f32>;
 };

 struct VertexOut {
     [[location(0)]] color : vec4<f32>;
     [[builtin(position)]] position : vec4<f32>;
 };

 [[stage(vertex)]]
 fn main(input : VertexIn) -> VertexOut {
     var output : VertexOut;
     output.position = vec4<f32>(input.position, 1.0);
     output.color = input.color;
     return output;
 })";
     wgpu::ShaderModule vsModule = utils::CreateShaderModule(device, vertexShader.c_str());

     std::string fragmentShader = R"(
 [[stage(fragment)]]
 fn main([[location(0)]] color : vec4<f32>) -> [[location(0)]] vec4<f32> {
     return color;
 })";
     wgpu::ShaderModule fsModule = utils::CreateShaderModule(device, fragmentShader.c_str());

     utils::ComboRenderPipelineDescriptor rpDesc;
     rpDesc.vertex.module = vsModule;
     rpDesc.cFragment.module = fsModule;
     rpDesc.vertex.bufferCount = 1;
     rpDesc.cBuffers[0].attributeCount = 2;
     rpDesc.cBuffers[0].arrayStride = 28;
     rpDesc.cAttributes[0].shaderLocation = 0;
     rpDesc.cAttributes[0].format = wgpu::VertexFormat::Float32x3;
     rpDesc.cAttributes[1].shaderLocation = 1;
     rpDesc.cAttributes[1].format = wgpu::VertexFormat::Float32x4;
     wgpu::RenderPipeline pipeline = device.CreateRenderPipeline(&rpDesc);
 }

 // Tests that shaders using struct function parameters and return values for shader stage I/O
 // can compile and link successfully.
 TEST_P(ShaderTests, WGSLStructIO) {
     std::string vertexShader = R"(
 struct VertexIn {
     [[location(0)]] position : vec3<f32>;
     [[location(1)]] color : vec4<f32>;
 };

 struct VertexOut {
     [[location(0)]] color : vec4<f32>;
     [[builtin(position)]] position : vec4<f32>;
 };

 [[stage(vertex)]]
 fn main(input : VertexIn) -> VertexOut {
     var output : VertexOut;
     output.position = vec4<f32>(input.position, 1.0);
     output.color = input.color;
     return output;
 })";
     wgpu::ShaderModule vsModule = utils::CreateShaderModule(device, vertexShader.c_str());

     std::string fragmentShader = R"(
 struct FragmentIn {
     [[location(0)]] color : vec4<f32>;
     [[builtin(position)]] fragCoord : vec4<f32>;
 };

 [[stage(fragment)]]
 fn main(input : FragmentIn) -> [[location(0)]] vec4<f32> {
     return input.color * input.fragCoord;
 })";
     wgpu::ShaderModule fsModule = utils::CreateShaderModule(device, fragmentShader.c_str());

     utils::ComboRenderPipelineDescriptor rpDesc;
     rpDesc.vertex.module = vsModule;
     rpDesc.cFragment.module = fsModule;
     rpDesc.vertex.bufferCount = 1;
     rpDesc.cBuffers[0].attributeCount = 2;
     rpDesc.cBuffers[0].arrayStride = 28;
     rpDesc.cAttributes[0].shaderLocation = 0;
     rpDesc.cAttributes[0].format = wgpu::VertexFormat::Float32x3;
     rpDesc.cAttributes[1].shaderLocation = 1;
     rpDesc.cAttributes[1].format = wgpu::VertexFormat::Float32x4;
     wgpu::RenderPipeline pipeline = device.CreateRenderPipeline(&rpDesc);
 }

 // Tests that shaders I/O structs that us compatible locations but are not sorted by hand can link.
 TEST_P(ShaderTests, WGSLUnsortedStructIO) {
     std::string vertexShader = R"(
 struct VertexIn {
     [[location(0)]] position : vec3<f32>;
     [[location(1)]] color : vec4<f32>;
 };

 struct VertexOut {
     [[builtin(position)]] position : vec4<f32>;
     [[location(0)]] color : vec4<f32>;
 };

 [[stage(vertex)]]
 fn main(input : VertexIn) -> VertexOut {
     var output : VertexOut;
     output.position = vec4<f32>(input.position, 1.0);
     output.color = input.color;
     return output;
 })";
     wgpu::ShaderModule vsModule = utils::CreateShaderModule(device, vertexShader.c_str());

     std::string fragmentShader = R"(
 struct FragmentIn {
     [[location(0)]] color : vec4<f32>;
     [[builtin(position)]] fragCoord : vec4<f32>;
 };

 [[stage(fragment)]]
 fn main(input : FragmentIn) -> [[location(0)]] vec4<f32> {
     return input.color * input.fragCoord;
 })";
     wgpu::ShaderModule fsModule = utils::CreateShaderModule(device, fragmentShader.c_str());

     utils::ComboRenderPipelineDescriptor rpDesc;
     rpDesc.vertex.module = vsModule;
     rpDesc.cFragment.module = fsModule;
     rpDesc.vertex.bufferCount = 1;
     rpDesc.cBuffers[0].attributeCount = 2;
     rpDesc.cBuffers[0].arrayStride = 28;
     rpDesc.cAttributes[0].shaderLocation = 0;
     rpDesc.cAttributes[0].format = wgpu::VertexFormat::Float32x3;
     rpDesc.cAttributes[1].shaderLocation = 1;
     rpDesc.cAttributes[1].format = wgpu::VertexFormat::Float32x4;
     wgpu::RenderPipeline pipeline = device.CreateRenderPipeline(&rpDesc);
 }

 // Tests that shaders I/O structs can be shared between vertex and fragment shaders.
 TEST_P(ShaderTests, WGSLSharedStructIO) {
     // TODO(tint:714): Not yet implemeneted in tint yet, but intended to work.
     DAWN_SKIP_TEST_IF(IsD3D12() || IsVulkan() || IsMetal() || IsOpenGL() || IsOpenGLES());

     std::string shader = R"(
 struct VertexIn {
     [[location(0)]] position : vec3<f32>;
     [[location(1)]] color : vec4<f32>;
 };

 struct VertexOut {
     [[location(0)]] color : vec4<f32>;
     [[builtin(position)]] position : vec4<f32>;
 };

 [[stage(vertex)]]
 fn vertexMain(input : VertexIn) -> VertexOut {
     var output : VertexOut;
     output.position = vec4<f32>(input.position, 1.0);
     output.color = input.color;
     return output;
 }

 [[stage(fragment)]]
 fn fragmentMain(input : VertexOut) -> [[location(0)]] vec4<f32> {
     return input.color;
 })";
     wgpu::ShaderModule shaderModule = utils::CreateShaderModule(device, shader.c_str());

     utils::ComboRenderPipelineDescriptor rpDesc;
     rpDesc.vertex.module = shaderModule;
     rpDesc.vertex.entryPoint = "vertexMain";
     rpDesc.cFragment.module = shaderModule;
     rpDesc.cFragment.entryPoint = "fragmentMain";
     rpDesc.vertex.bufferCount = 1;
     rpDesc.cBuffers[0].attributeCount = 2;
     rpDesc.cBuffers[0].arrayStride = 28;
     rpDesc.cAttributes[0].shaderLocation = 0;
     rpDesc.cAttributes[0].format = wgpu::VertexFormat::Float32x3;
     rpDesc.cAttributes[1].shaderLocation = 1;
     rpDesc.cAttributes[1].format = wgpu::VertexFormat::Float32x4;
     wgpu::RenderPipeline pipeline = device.CreateRenderPipeline(&rpDesc);
 }

 DAWN_INSTANTIATE_TEST(ShaderTests,
                       D3D12Backend(),
                       MetalBackend(),
                       OpenGLBackend(),
                       OpenGLESBackend(),
                       VulkanBackend());
	// Copyright 2021 The Dawn Authors
	//
	// Licensed under the Apache License, Version 2.0 (the "License");
	// you may not use this file except in compliance with the License.
	// You may obtain a copy of the License at
	//
	// http://www.apache.org/licenses/LICENSE-2.0
	//
	// Unless required by applicable law or agreed to in writing, software
	// distributed under the License is distributed on an "AS IS" BASIS,
	// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	// See the License for the specific language governing permissions and
	// limitations under the License.

	#include "tests/DawnTest.h"

	#include "utils/ComboRenderPipelineDescriptor.h"
	#include "utils/WGPUHelpers.h"

	#include <vector>

	class ShaderTests : public DawnTest {};

	// Test that log2 is being properly calculated, base on crbug.com/1046622
	TEST_P(ShaderTests, ComputeLog2) {
	uint32_t const kSteps = 19;
	std::vector<uint32_t> data(kSteps, 0);
	std::vector<uint32_t> expected{0, 1, 1, 2, 2, 3, 3, 4, 4, 5, 5, 6, 6, 7, 7, 8, 8, 9, 32};
	uint64_t bufferSize = static_cast<uint64_t>(data.size() * sizeof(uint32_t));
	wgpu::Buffer buffer = utils::CreateBufferFromData(
	device, data.data(), bufferSize, wgpu::BufferUsage::Storage \| wgpu::BufferUsage::CopySrc);

	std::string shader = R"(
	[[block]] struct Buf {
	data : array<u32, 19>;
	};

	[[group(0), binding(0)]] var<storage> buf : [[access(read_write)]] Buf;

	[[stage(compute)]] fn main() {
	let factor : f32 = 1.0001;

	buf.data[0] = u32(log2(1.0 * factor));
	buf.data[1] = u32(log2(2.0 * factor));
	buf.data[2] = u32(log2(3.0 * factor));
	buf.data[3] = u32(log2(4.0 * factor));
	buf.data[4] = u32(log2(7.0 * factor));
	buf.data[5] = u32(log2(8.0 * factor));
	buf.data[6] = u32(log2(15.0 * factor));
	buf.data[7] = u32(log2(16.0 * factor));
	buf.data[8] = u32(log2(31.0 * factor));
	buf.data[9] = u32(log2(32.0 * factor));
	buf.data[10] = u32(log2(63.0 * factor));
	buf.data[11] = u32(log2(64.0 * factor));
	buf.data[12] = u32(log2(127.0 * factor));
	buf.data[13] = u32(log2(128.0 * factor));
	buf.data[14] = u32(log2(255.0 * factor));
	buf.data[15] = u32(log2(256.0 * factor));
	buf.data[16] = u32(log2(511.0 * factor));
	buf.data[17] = u32(log2(512.0 * factor));
	buf.data[18] = u32(log2(4294967295.0 * factor));
	})";

	wgpu::ComputePipelineDescriptor csDesc;
	csDesc.computeStage.module = utils::CreateShaderModule(device, shader.c_str());
	csDesc.computeStage.entryPoint = "main";
	wgpu::ComputePipeline pipeline = device.CreateComputePipeline(&csDesc);

	wgpu::BindGroup bindGroup =
	utils::MakeBindGroup(device, pipeline.GetBindGroupLayout(0), {{0, buffer}});

	wgpu::CommandBuffer commands;
	{
	wgpu::CommandEncoder encoder = device.CreateCommandEncoder();
	wgpu::ComputePassEncoder pass = encoder.BeginComputePass();
	pass.SetPipeline(pipeline);
	pass.SetBindGroup(0, bindGroup);
	pass.Dispatch(1);
	pass.EndPass();

	commands = encoder.Finish();
	}

	queue.Submit(1, &commands);

	EXPECT_BUFFER_U32_RANGE_EQ(expected.data(), buffer, 0, kSteps);
	}

	TEST_P(ShaderTests, BadWGSL) {
	DAWN_SKIP_TEST_IF(HasToggleEnabled("skip_validation"));

	std::string shader = R"(
	I am an invalid shader and should never pass validation!
	})";
	ASSERT_DEVICE_ERROR(utils::CreateShaderModule(device, shader.c_str()));
	}

	// Tests that shaders using non-struct function parameters and return values for shader stage I/O
	// can compile and link successfully.
	TEST_P(ShaderTests, WGSLParamIO) {
	std::string vertexShader = R"(
	[[stage(vertex)]]
	fn main([[builtin(vertex_index)]] VertexIndex : u32) -> [[builtin(position)]] vec4<f32> {
	let pos : array<vec2<f32>, 3> = array<vec2<f32>, 3>(
	vec2<f32>(-1.0, 1.0),
	vec2<f32>( 1.0, 1.0),
	vec2<f32>( 0.0, -1.0));
	return vec4<f32>(pos[VertexIndex], 0.0, 1.0);
	})";
	wgpu::ShaderModule vsModule = utils::CreateShaderModule(device, vertexShader.c_str());

	std::string fragmentShader = R"(
	[[stage(fragment)]]
	fn main([[builtin(position)]] fragCoord : vec4<f32>) -> [[location(0)]] vec4<f32> {
	return vec4<f32>(fragCoord.xy, 0.0, 1.0);
	})";
	wgpu::ShaderModule fsModule = utils::CreateShaderModule(device, fragmentShader.c_str());

	utils::ComboRenderPipelineDescriptor rpDesc;
	rpDesc.vertex.module = vsModule;
	rpDesc.cFragment.module = fsModule;
	wgpu::RenderPipeline pipeline = device.CreateRenderPipeline(&rpDesc);
	}

	// Tests that a vertex shader using struct function parameters and return values for shader stage
	// I/O can compile and link successfully against a fragement shader using compatible non-struct I/O.
	TEST_P(ShaderTests, WGSLMixedStructParamIO) {
	std::string vertexShader = R"(
	struct VertexIn {
	[[location(0)]] position : vec3<f32>;
	[[location(1)]] color : vec4<f32>;
	};

	struct VertexOut {
	[[location(0)]] color : vec4<f32>;
	[[builtin(position)]] position : vec4<f32>;
	};

	[[stage(vertex)]]
	fn main(input : VertexIn) -> VertexOut {
	var output : VertexOut;
	output.position = vec4<f32>(input.position, 1.0);
	output.color = input.color;
	return output;
	})";
	wgpu::ShaderModule vsModule = utils::CreateShaderModule(device, vertexShader.c_str());

	std::string fragmentShader = R"(
	[[stage(fragment)]]
	fn main([[location(0)]] color : vec4<f32>) -> [[location(0)]] vec4<f32> {
	return color;
	})";
	wgpu::ShaderModule fsModule = utils::CreateShaderModule(device, fragmentShader.c_str());

	utils::ComboRenderPipelineDescriptor rpDesc;
	rpDesc.vertex.module = vsModule;
	rpDesc.cFragment.module = fsModule;
	rpDesc.vertex.bufferCount = 1;
	rpDesc.cBuffers[0].attributeCount = 2;
	rpDesc.cBuffers[0].arrayStride = 28;
	rpDesc.cAttributes[0].shaderLocation = 0;
	rpDesc.cAttributes[0].format = wgpu::VertexFormat::Float32x3;
	rpDesc.cAttributes[1].shaderLocation = 1;
	rpDesc.cAttributes[1].format = wgpu::VertexFormat::Float32x4;
	wgpu::RenderPipeline pipeline = device.CreateRenderPipeline(&rpDesc);
	}

	// Tests that shaders using struct function parameters and return values for shader stage I/O
	// can compile and link successfully.
	TEST_P(ShaderTests, WGSLStructIO) {
	std::string vertexShader = R"(
	struct VertexIn {
	[[location(0)]] position : vec3<f32>;
	[[location(1)]] color : vec4<f32>;
	};

	struct VertexOut {
	[[location(0)]] color : vec4<f32>;
	[[builtin(position)]] position : vec4<f32>;
	};

	[[stage(vertex)]]
	fn main(input : VertexIn) -> VertexOut {
	var output : VertexOut;
	output.position = vec4<f32>(input.position, 1.0);
	output.color = input.color;
	return output;
	})";
	wgpu::ShaderModule vsModule = utils::CreateShaderModule(device, vertexShader.c_str());

	std::string fragmentShader = R"(
	struct FragmentIn {
	[[location(0)]] color : vec4<f32>;
	[[builtin(position)]] fragCoord : vec4<f32>;
	};

	[[stage(fragment)]]
	fn main(input : FragmentIn) -> [[location(0)]] vec4<f32> {
	return input.color * input.fragCoord;
	})";
	wgpu::ShaderModule fsModule = utils::CreateShaderModule(device, fragmentShader.c_str());

	utils::ComboRenderPipelineDescriptor rpDesc;
	rpDesc.vertex.module = vsModule;
	rpDesc.cFragment.module = fsModule;
	rpDesc.vertex.bufferCount = 1;
	rpDesc.cBuffers[0].attributeCount = 2;
	rpDesc.cBuffers[0].arrayStride = 28;
	rpDesc.cAttributes[0].shaderLocation = 0;
	rpDesc.cAttributes[0].format = wgpu::VertexFormat::Float32x3;
	rpDesc.cAttributes[1].shaderLocation = 1;
	rpDesc.cAttributes[1].format = wgpu::VertexFormat::Float32x4;
	wgpu::RenderPipeline pipeline = device.CreateRenderPipeline(&rpDesc);
	}

	// Tests that shaders I/O structs that us compatible locations but are not sorted by hand can link.
	TEST_P(ShaderTests, WGSLUnsortedStructIO) {
	std::string vertexShader = R"(
	struct VertexIn {
	[[location(0)]] position : vec3<f32>;
	[[location(1)]] color : vec4<f32>;
	};

	struct VertexOut {
	[[builtin(position)]] position : vec4<f32>;
	[[location(0)]] color : vec4<f32>;
	};

	[[stage(vertex)]]
	fn main(input : VertexIn) -> VertexOut {
	var output : VertexOut;
	output.position = vec4<f32>(input.position, 1.0);
	output.color = input.color;
	return output;
	})";
	wgpu::ShaderModule vsModule = utils::CreateShaderModule(device, vertexShader.c_str());

	std::string fragmentShader = R"(
	struct FragmentIn {
	[[location(0)]] color : vec4<f32>;
	[[builtin(position)]] fragCoord : vec4<f32>;
	};

	[[stage(fragment)]]
	fn main(input : FragmentIn) -> [[location(0)]] vec4<f32> {
	return input.color * input.fragCoord;
	})";
	wgpu::ShaderModule fsModule = utils::CreateShaderModule(device, fragmentShader.c_str());

	utils::ComboRenderPipelineDescriptor rpDesc;
	rpDesc.vertex.module = vsModule;
	rpDesc.cFragment.module = fsModule;
	rpDesc.vertex.bufferCount = 1;
	rpDesc.cBuffers[0].attributeCount = 2;
	rpDesc.cBuffers[0].arrayStride = 28;
	rpDesc.cAttributes[0].shaderLocation = 0;
	rpDesc.cAttributes[0].format = wgpu::VertexFormat::Float32x3;
	rpDesc.cAttributes[1].shaderLocation = 1;
	rpDesc.cAttributes[1].format = wgpu::VertexFormat::Float32x4;
	wgpu::RenderPipeline pipeline = device.CreateRenderPipeline(&rpDesc);
	}

	// Tests that shaders I/O structs can be shared between vertex and fragment shaders.
	TEST_P(ShaderTests, WGSLSharedStructIO) {
	// TODO(tint:714): Not yet implemeneted in tint yet, but intended to work.
	DAWN_SKIP_TEST_IF(IsD3D12() \|\| IsVulkan() \|\| IsMetal() \|\| IsOpenGL() \|\| IsOpenGLES());

	std::string shader = R"(
	struct VertexIn {
	[[location(0)]] position : vec3<f32>;
	[[location(1)]] color : vec4<f32>;
	};

	struct VertexOut {
	[[location(0)]] color : vec4<f32>;
	[[builtin(position)]] position : vec4<f32>;
	};

	[[stage(vertex)]]
	fn vertexMain(input : VertexIn) -> VertexOut {
	var output : VertexOut;
	output.position = vec4<f32>(input.position, 1.0);
	output.color = input.color;
	return output;
	}

	[[stage(fragment)]]
	fn fragmentMain(input : VertexOut) -> [[location(0)]] vec4<f32> {
	return input.color;
	})";
	wgpu::ShaderModule shaderModule = utils::CreateShaderModule(device, shader.c_str());

	utils::ComboRenderPipelineDescriptor rpDesc;
	rpDesc.vertex.module = shaderModule;
	rpDesc.vertex.entryPoint = "vertexMain";
	rpDesc.cFragment.module = shaderModule;
	rpDesc.cFragment.entryPoint = "fragmentMain";
	rpDesc.vertex.bufferCount = 1;
	rpDesc.cBuffers[0].attributeCount = 2;
	rpDesc.cBuffers[0].arrayStride = 28;
	rpDesc.cAttributes[0].shaderLocation = 0;
	rpDesc.cAttributes[0].format = wgpu::VertexFormat::Float32x3;
	rpDesc.cAttributes[1].shaderLocation = 1;
	rpDesc.cAttributes[1].format = wgpu::VertexFormat::Float32x4;
	wgpu::RenderPipeline pipeline = device.CreateRenderPipeline(&rpDesc);
	}

	DAWN_INSTANTIATE_TEST(ShaderTests,
	D3D12Backend(),
	MetalBackend(),
	OpenGLBackend(),
	OpenGLESBackend(),
	VulkanBackend());