fuzzers/tint_common_fuzzer.cc - tint - Git at Google

 // Copyright 2021 The Tint 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 "fuzzers/tint_common_fuzzer.h"

 #include <cstring>
 #include <memory>
 #include <sstream>
 #include <string>
 #include <utility>
 #include <vector>

 #if TINT_BUILD_SPV_READER
 #include "spirv-tools/libspirv.hpp"
 #endif  // TINT_BUILD_SPV_READER

 #include "src/ast/module.h"
 #include "src/diagnostic/formatter.h"
 #include "src/program.h"

 namespace tint {
 namespace fuzzers {

 namespace {

 [[noreturn]] void FatalError(const tint::diag::List& diags,
                              const std::string& msg = "") {
   auto printer = tint::diag::Printer::create(stderr, true);
   if (!msg.empty()) {
     printer->write(msg + "\n", {diag::Color::kRed, true});
   }
   tint::diag::Formatter().format(diags, printer.get());
   __builtin_trap();
 }

 [[noreturn]] void TintInternalCompilerErrorReporter(
     const tint::diag::List& diagnostics) {
   FatalError(diagnostics);
 }

 transform::VertexAttributeDescriptor ExtractVertexAttributeDescriptor(
     Reader* r) {
   transform::VertexAttributeDescriptor desc{};
   desc.format = r->enum_class<transform::VertexFormat>(
       static_cast<uint8_t>(transform::VertexFormat::kLastEntry) + 1);
   desc.offset = r->read<uint32_t>();
   desc.shader_location = r->read<uint32_t>();
   return desc;
 }

 transform::VertexBufferLayoutDescriptor ExtractVertexBufferLayoutDescriptor(
     Reader* r) {
   transform::VertexBufferLayoutDescriptor desc;
   desc.array_stride = r->read<uint32_t>();
   desc.step_mode = r->enum_class<transform::VertexStepMode>(
       static_cast<uint8_t>(transform::VertexStepMode::kLastEntry) + 1);
   desc.attributes = r->vector(ExtractVertexAttributeDescriptor);
   return desc;
 }

 bool SPIRVToolsValidationCheck(const tint::Program& program,
                                const std::vector<uint32_t>& spirv) {
   spvtools::SpirvTools tools(SPV_ENV_VULKAN_1_1);
   const tint::diag::List& diags = program.Diagnostics();
   tools.SetMessageConsumer([diags](spv_message_level_t, const char*,
                                    const spv_position_t& pos, const char* msg) {
     std::stringstream out;
     out << "Unexpected spirv-val error:\n"
         << (pos.line + 1) << ":" << (pos.column + 1) << ": " << msg
         << std::endl;

     auto printer = tint::diag::Printer::create(stderr, true);
     printer->write(out.str(), {diag::Color::kYellow, false});
     tint::diag::Formatter().format(diags, printer.get());
   });

   return tools.Validate(spirv.data(), spirv.size(),
                         spvtools::ValidatorOptions());
 }

 }  // namespace

 Reader::Reader(const uint8_t* data, size_t size) : data_(data), size_(size) {}

 std::string Reader::string() {
   auto count = read<uint8_t>();
   if (failed_ || size_ < count) {
     mark_failed();
     return "";
   }
   std::string out(data_, data_ + count);
   data_ += count;
   size_ -= count;
   return out;
 }

 void Reader::mark_failed() {
   size_ = 0;
   failed_ = true;
 }

 void Reader::read(void* out, size_t n) {
   if (n > size_) {
     mark_failed();
     return;
   }
   memcpy(out, data_, n);
   data_ += n;
   size_ -= n;
 }

 void ExtractBindingRemapperInputs(Reader* r, tint::transform::DataMap* inputs) {
   struct Config {
     uint8_t old_group;
     uint8_t old_binding;
     uint8_t new_group;
     uint8_t new_binding;
     ast::Access new_access;
   };

   std::vector<Config> configs = r->vector<Config>();
   transform::BindingRemapper::BindingPoints binding_points;
   transform::BindingRemapper::AccessControls accesses;
   for (const auto& config : configs) {
     binding_points[{config.old_binding, config.old_group}] = {
         config.new_binding, config.new_group};
     accesses[{config.old_binding, config.old_group}] = config.new_access;
   }

   inputs->Add<transform::BindingRemapper::Remappings>(binding_points, accesses);
 }

 void ExtractFirstIndexOffsetInputs(Reader* r,
                                    tint::transform::DataMap* inputs) {
   struct Config {
     uint32_t group;
     uint32_t binding;
   };

   Config config = r->read<Config>();
   inputs->Add<tint::transform::FirstIndexOffset::BindingPoint>(config.binding,
                                                                config.group);
 }

 void ExtractSingleEntryPointInputs(Reader* r,
                                    tint::transform::DataMap* inputs) {
   std::string input = r->string();
   transform::SingleEntryPoint::Config cfg(input);
   inputs->Add<transform::SingleEntryPoint::Config>(cfg);
 }

 void ExtractVertexPullingInputs(Reader* r, tint::transform::DataMap* inputs) {
   transform::VertexPulling::Config cfg;
   cfg.entry_point_name = r->string();
   cfg.vertex_state = r->vector(ExtractVertexBufferLayoutDescriptor);
   cfg.pulling_group = r->read<uint32_t>();
   inputs->Add<transform::VertexPulling::Config>(cfg);
 }

 void ExtractSpirvOptions(Reader* r, writer::spirv::Options* options) {
   *options = r->read<writer::spirv::Options>();
 }

 void ExtractWgslOptions(Reader* r, writer::wgsl::Options* options) {
   *options = r->read<writer::wgsl::Options>();
 }

 void ExtractHlslOptions(Reader* r, writer::hlsl::Options* options) {
   *options = r->read<writer::hlsl::Options>();
 }

 void ExtractMslOptions(Reader* r, writer::msl::Options* options) {
   *options = r->read<writer::msl::Options>();
 }

 CommonFuzzer::CommonFuzzer(InputFormat input, OutputFormat output)
     : input_(input),
       output_(output),
       transform_manager_(nullptr),
       inspector_enabled_(false) {}

 CommonFuzzer::~CommonFuzzer() = default;

 int CommonFuzzer::Run(const uint8_t* data, size_t size) {
   tint::SetInternalCompilerErrorReporter(&TintInternalCompilerErrorReporter);

   Program program;

 #if TINT_BUILD_SPV_READER
   std::vector<uint32_t> spirv_input(size / sizeof(uint32_t));

 #endif  // TINT_BUILD_SPV_READER

   switch (input_) {
 #if TINT_BUILD_WGSL_READER
     case InputFormat::kWGSL: {
       // Clear any existing diagnostics, as these will hold pointers to file_,
       // which we are about to release.
       diagnostics_ = {};
       std::string str(reinterpret_cast<const char*>(data), size);
       file_ = std::make_unique<Source::File>("test.wgsl", str);
       program = reader::wgsl::Parse(file_.get());
       break;
     }
 #endif  // TINT_BUILD_WGSL_READER
 #if TINT_BUILD_SPV_READER
     case InputFormat::kSpv: {
       // `spirv_input` has been initialized with the capacity to store `size /
       // sizeof(uint32_t)` uint32_t values. If `size` is not a multiple of
       // sizeof(uint32_t) then not all of `data` can be copied into
       // `spirv_input`, and any trailing bytes are discarded.
       std::memcpy(spirv_input.data(), data,
                   spirv_input.size() * sizeof(uint32_t));
       if (spirv_input.empty()) {
         return 0;
       }
       program = reader::spirv::Parse(spirv_input);
       break;
     }
 #endif  // TINT_BUILD_SPV_READER
     default:
       return 0;
   }

   if (output_ == OutputFormat::kNone) {
     return 0;
   }

   if (!program.IsValid()) {
     diagnostics_ = program.Diagnostics();
     return 0;
   }

 #if TINT_BUILD_SPV_READER
   if (input_ == InputFormat::kSpv &&
       !SPIRVToolsValidationCheck(program, spirv_input)) {
     FatalError(program.Diagnostics(),
                "Fuzzing detected invalid input spirv not being caught by Tint");
   }
 #endif  // TINT_BUILD_SPV_READER

   if (inspector_enabled_) {
     inspector::Inspector inspector(&program);

     auto entry_points = inspector.GetEntryPoints();
     if (inspector.has_error()) {
       diagnostics_.add_error(tint::diag::System::Inspector, inspector.error());
       return 0;
     }

     for (auto& ep : entry_points) {
       auto remapped_name = inspector.GetRemappedNameForEntryPoint(ep.name);
       if (inspector.has_error()) {
         diagnostics_.add_error(tint::diag::System::Inspector,
                                inspector.error());
         return 0;
       }

       auto constant_ids = inspector.GetConstantIDs();
       if (inspector.has_error()) {
         diagnostics_.add_error(tint::diag::System::Inspector,
                                inspector.error());
         return 0;
       }

       auto uniform_bindings =
           inspector.GetUniformBufferResourceBindings(ep.name);
       if (inspector.has_error()) {
         diagnostics_.add_error(tint::diag::System::Inspector,
                                inspector.error());
         return 0;
       }

       auto storage_bindings =
           inspector.GetStorageBufferResourceBindings(ep.name);
       if (inspector.has_error()) {
         diagnostics_.add_error(tint::diag::System::Inspector,
                                inspector.error());
         return 0;
       }

       auto readonly_bindings =
           inspector.GetReadOnlyStorageBufferResourceBindings(ep.name);
       if (inspector.has_error()) {
         diagnostics_.add_error(tint::diag::System::Inspector,
                                inspector.error());
         return 0;
       }

       auto sampler_bindings = inspector.GetSamplerResourceBindings(ep.name);
       if (inspector.has_error()) {
         diagnostics_.add_error(tint::diag::System::Inspector,
                                inspector.error());
         return 0;
       }

       auto comparison_sampler_bindings =
           inspector.GetComparisonSamplerResourceBindings(ep.name);
       if (inspector.has_error()) {
         diagnostics_.add_error(tint::diag::System::Inspector,
                                inspector.error());
         return 0;
       }

       auto sampled_texture_bindings =
           inspector.GetSampledTextureResourceBindings(ep.name);
       if (inspector.has_error()) {
         diagnostics_.add_error(tint::diag::System::Inspector,
                                inspector.error());
         return 0;
       }

       auto multisampled_texture_bindings =
           inspector.GetMultisampledTextureResourceBindings(ep.name);
       if (inspector.has_error()) {
         diagnostics_.add_error(tint::diag::System::Inspector,
                                inspector.error());
         return 0;
       }
     }
   }

   if (transform_manager_) {
     auto out = transform_manager_->Run(&program, transform_inputs_);
     if (!out.program.IsValid()) {
       // Transforms can produce error messages for bad input.
       // Catch ICEs and errors from non transform systems.
       for (const auto& diag : out.program.Diagnostics()) {
         if (diag.severity > diag::Severity::Error ||
             diag.system != diag::System::Transform) {
           FatalError(out.program.Diagnostics(),
                      "Fuzzing detected valid input program being transformed "
                      "into an invalid output program");
         }
       }
     }

     program = std::move(out.program);
   }

   switch (output_) {
     case OutputFormat::kWGSL: {
 #if TINT_BUILD_WGSL_WRITER
       auto result = writer::wgsl::Generate(&program, options_wgsl_);
       generated_wgsl_ = std::move(result.wgsl);
       if (!result.success) {
         FatalError(program.Diagnostics(),
                    "WGSL writer failed: " + result.error);
       }
 #endif  // TINT_BUILD_WGSL_WRITER
       break;
     }
     case OutputFormat::kSpv: {
 #if TINT_BUILD_SPV_WRITER
       auto result = writer::spirv::Generate(&program, options_spirv_);
       generated_spirv_ = std::move(result.spirv);
       if (!result.success) {
         FatalError(program.Diagnostics(),
                    "SPIR-V writer failed: " + result.error);
       }
       if (!SPIRVToolsValidationCheck(program, generated_spirv_)) {
         FatalError(program.Diagnostics(),
                    "Fuzzing detected invalid spirv being emitted by Tint");
       }

 #endif  // TINT_BUILD_SPV_WRITER
       break;
     }
     case OutputFormat::kHLSL: {
 #if TINT_BUILD_HLSL_WRITER
       auto result = writer::hlsl::Generate(&program, options_hlsl_);
       generated_hlsl_ = std::move(result.hlsl);
       if (!result.success) {
         FatalError(program.Diagnostics(),
                    "HLSL writer failed: " + result.error);
       }
 #endif  // TINT_BUILD_HLSL_WRITER
       break;
     }
     case OutputFormat::kMSL: {
 #if TINT_BUILD_MSL_WRITER
       auto result = writer::msl::Generate(&program, options_msl_);
       generated_msl_ = std::move(result.msl);
       if (!result.success) {
         FatalError(program.Diagnostics(), "MSL writer failed: " + result.error);
       }
 #endif  // TINT_BUILD_MSL_WRITER
       break;
     }
     case OutputFormat::kNone:
       break;
   }

   return 0;
 }

 }  // namespace fuzzers
 }  // namespace tint
	// Copyright 2021 The Tint 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 "fuzzers/tint_common_fuzzer.h"

	#include <cstring>
	#include <memory>
	#include <sstream>
	#include <string>
	#include <utility>
	#include <vector>

	#if TINT_BUILD_SPV_READER
	#include "spirv-tools/libspirv.hpp"
	#endif // TINT_BUILD_SPV_READER

	#include "src/ast/module.h"
	#include "src/diagnostic/formatter.h"
	#include "src/program.h"

	namespace tint {
	namespace fuzzers {

	namespace {

	[[noreturn]] void FatalError(const tint::diag::List& diags,
	const std::string& msg = "") {
	auto printer = tint::diag::Printer::create(stderr, true);
	if (!msg.empty()) {
	printer->write(msg + "\n", {diag::Color::kRed, true});
	}
	tint::diag::Formatter().format(diags, printer.get());
	__builtin_trap();
	}

	[[noreturn]] void TintInternalCompilerErrorReporter(
	const tint::diag::List& diagnostics) {
	FatalError(diagnostics);
	}

	transform::VertexAttributeDescriptor ExtractVertexAttributeDescriptor(
	Reader* r) {
	transform::VertexAttributeDescriptor desc{};
	desc.format = r->enum_class<transform::VertexFormat>(
	static_cast<uint8_t>(transform::VertexFormat::kLastEntry) + 1);
	desc.offset = r->read<uint32_t>();
	desc.shader_location = r->read<uint32_t>();
	return desc;
	}

	transform::VertexBufferLayoutDescriptor ExtractVertexBufferLayoutDescriptor(
	Reader* r) {
	transform::VertexBufferLayoutDescriptor desc;
	desc.array_stride = r->read<uint32_t>();
	desc.step_mode = r->enum_class<transform::VertexStepMode>(
	static_cast<uint8_t>(transform::VertexStepMode::kLastEntry) + 1);
	desc.attributes = r->vector(ExtractVertexAttributeDescriptor);
	return desc;
	}

	bool SPIRVToolsValidationCheck(const tint::Program& program,
	const std::vector<uint32_t>& spirv) {
	spvtools::SpirvTools tools(SPV_ENV_VULKAN_1_1);
	const tint::diag::List& diags = program.Diagnostics();
	tools.SetMessageConsumer([diags](spv_message_level_t, const char*,
	const spv_position_t& pos, const char* msg) {
	std::stringstream out;
	out << "Unexpected spirv-val error:\n"
	<< (pos.line + 1) << ":" << (pos.column + 1) << ": " << msg
	<< std::endl;

	auto printer = tint::diag::Printer::create(stderr, true);
	printer->write(out.str(), {diag::Color::kYellow, false});
	tint::diag::Formatter().format(diags, printer.get());
	});

	return tools.Validate(spirv.data(), spirv.size(),
	spvtools::ValidatorOptions());
	}

	} // namespace

	Reader::Reader(const uint8_t* data, size_t size) : data_(data), size_(size) {}

	std::string Reader::string() {
	auto count = read<uint8_t>();
	if (failed_ \|\| size_ < count) {
	mark_failed();
	return "";
	}
	std::string out(data_, data_ + count);
	data_ += count;
	size_ -= count;
	return out;
	}

	void Reader::mark_failed() {
	size_ = 0;
	failed_ = true;
	}

	void Reader::read(void* out, size_t n) {
	if (n > size_) {
	mark_failed();
	return;
	}
	memcpy(out, data_, n);
	data_ += n;
	size_ -= n;
	}

	void ExtractBindingRemapperInputs(Reader* r, tint::transform::DataMap* inputs) {
	struct Config {
	uint8_t old_group;
	uint8_t old_binding;
	uint8_t new_group;
	uint8_t new_binding;
	ast::Access new_access;
	};

	std::vector<Config> configs = r->vector<Config>();
	transform::BindingRemapper::BindingPoints binding_points;
	transform::BindingRemapper::AccessControls accesses;
	for (const auto& config : configs) {
	binding_points[{config.old_binding, config.old_group}] = {
	config.new_binding, config.new_group};
	accesses[{config.old_binding, config.old_group}] = config.new_access;
	}

	inputs->Add<transform::BindingRemapper::Remappings>(binding_points, accesses);
	}

	void ExtractFirstIndexOffsetInputs(Reader* r,
	tint::transform::DataMap* inputs) {
	struct Config {
	uint32_t group;
	uint32_t binding;
	};

	Config config = r->read<Config>();
	inputs->Add<tint::transform::FirstIndexOffset::BindingPoint>(config.binding,
	config.group);
	}

	void ExtractSingleEntryPointInputs(Reader* r,
	tint::transform::DataMap* inputs) {
	std::string input = r->string();
	transform::SingleEntryPoint::Config cfg(input);
	inputs->Add<transform::SingleEntryPoint::Config>(cfg);
	}

	void ExtractVertexPullingInputs(Reader* r, tint::transform::DataMap* inputs) {
	transform::VertexPulling::Config cfg;
	cfg.entry_point_name = r->string();
	cfg.vertex_state = r->vector(ExtractVertexBufferLayoutDescriptor);
	cfg.pulling_group = r->read<uint32_t>();
	inputs->Add<transform::VertexPulling::Config>(cfg);
	}

	void ExtractSpirvOptions(Reader* r, writer::spirv::Options* options) {
	*options = r->read<writer::spirv::Options>();
	}

	void ExtractWgslOptions(Reader* r, writer::wgsl::Options* options) {
	*options = r->read<writer::wgsl::Options>();
	}

	void ExtractHlslOptions(Reader* r, writer::hlsl::Options* options) {
	*options = r->read<writer::hlsl::Options>();
	}

	void ExtractMslOptions(Reader* r, writer::msl::Options* options) {
	*options = r->read<writer::msl::Options>();
	}

	CommonFuzzer::CommonFuzzer(InputFormat input, OutputFormat output)
	: input_(input),
	output_(output),
	transform_manager_(nullptr),
	inspector_enabled_(false) {}

	CommonFuzzer::~CommonFuzzer() = default;

	int CommonFuzzer::Run(const uint8_t* data, size_t size) {
	tint::SetInternalCompilerErrorReporter(&TintInternalCompilerErrorReporter);

	Program program;

	#if TINT_BUILD_SPV_READER
	std::vector<uint32_t> spirv_input(size / sizeof(uint32_t));

	#endif // TINT_BUILD_SPV_READER

	switch (input_) {
	#if TINT_BUILD_WGSL_READER
	case InputFormat::kWGSL: {
	// Clear any existing diagnostics, as these will hold pointers to file_,
	// which we are about to release.
	diagnostics_ = {};
	std::string str(reinterpret_cast<const char*>(data), size);
	file_ = std::make_unique<Source::File>("test.wgsl", str);
	program = reader::wgsl::Parse(file_.get());
	break;
	}
	#endif // TINT_BUILD_WGSL_READER
	#if TINT_BUILD_SPV_READER
	case InputFormat::kSpv: {
	// `spirv_input` has been initialized with the capacity to store `size /
	// sizeof(uint32_t)` uint32_t values. If `size` is not a multiple of
	// sizeof(uint32_t) then not all of `data` can be copied into
	// `spirv_input`, and any trailing bytes are discarded.
	std::memcpy(spirv_input.data(), data,
	spirv_input.size() * sizeof(uint32_t));
	if (spirv_input.empty()) {
	return 0;
	}
	program = reader::spirv::Parse(spirv_input);
	break;
	}
	#endif // TINT_BUILD_SPV_READER
	default:
	return 0;
	}

	if (output_ == OutputFormat::kNone) {
	return 0;
	}

	if (!program.IsValid()) {
	diagnostics_ = program.Diagnostics();
	return 0;
	}

	#if TINT_BUILD_SPV_READER
	if (input_ == InputFormat::kSpv &&
	!SPIRVToolsValidationCheck(program, spirv_input)) {
	FatalError(program.Diagnostics(),
	"Fuzzing detected invalid input spirv not being caught by Tint");
	}
	#endif // TINT_BUILD_SPV_READER

	if (inspector_enabled_) {
	inspector::Inspector inspector(&program);

	auto entry_points = inspector.GetEntryPoints();
	if (inspector.has_error()) {
	diagnostics_.add_error(tint::diag::System::Inspector, inspector.error());
	return 0;
	}

	for (auto& ep : entry_points) {
	auto remapped_name = inspector.GetRemappedNameForEntryPoint(ep.name);
	if (inspector.has_error()) {
	diagnostics_.add_error(tint::diag::System::Inspector,
	inspector.error());
	return 0;
	}

	auto constant_ids = inspector.GetConstantIDs();
	if (inspector.has_error()) {
	diagnostics_.add_error(tint::diag::System::Inspector,
	inspector.error());
	return 0;
	}

	auto uniform_bindings =
	inspector.GetUniformBufferResourceBindings(ep.name);
	if (inspector.has_error()) {
	diagnostics_.add_error(tint::diag::System::Inspector,
	inspector.error());
	return 0;
	}

	auto storage_bindings =
	inspector.GetStorageBufferResourceBindings(ep.name);
	if (inspector.has_error()) {
	diagnostics_.add_error(tint::diag::System::Inspector,
	inspector.error());
	return 0;
	}

	auto readonly_bindings =
	inspector.GetReadOnlyStorageBufferResourceBindings(ep.name);
	if (inspector.has_error()) {
	diagnostics_.add_error(tint::diag::System::Inspector,
	inspector.error());
	return 0;
	}

	auto sampler_bindings = inspector.GetSamplerResourceBindings(ep.name);
	if (inspector.has_error()) {
	diagnostics_.add_error(tint::diag::System::Inspector,
	inspector.error());
	return 0;
	}

	auto comparison_sampler_bindings =
	inspector.GetComparisonSamplerResourceBindings(ep.name);
	if (inspector.has_error()) {
	diagnostics_.add_error(tint::diag::System::Inspector,
	inspector.error());
	return 0;
	}

	auto sampled_texture_bindings =
	inspector.GetSampledTextureResourceBindings(ep.name);
	if (inspector.has_error()) {
	diagnostics_.add_error(tint::diag::System::Inspector,
	inspector.error());
	return 0;
	}

	auto multisampled_texture_bindings =
	inspector.GetMultisampledTextureResourceBindings(ep.name);
	if (inspector.has_error()) {
	diagnostics_.add_error(tint::diag::System::Inspector,
	inspector.error());
	return 0;
	}
	}
	}

	if (transform_manager_) {
	auto out = transform_manager_->Run(&program, transform_inputs_);
	if (!out.program.IsValid()) {
	// Transforms can produce error messages for bad input.
	// Catch ICEs and errors from non transform systems.
	for (const auto& diag : out.program.Diagnostics()) {
	if (diag.severity > diag::Severity::Error \|\|
	diag.system != diag::System::Transform) {
	FatalError(out.program.Diagnostics(),
	"Fuzzing detected valid input program being transformed "
	"into an invalid output program");
	}
	}
	}

	program = std::move(out.program);
	}

	switch (output_) {
	case OutputFormat::kWGSL: {
	#if TINT_BUILD_WGSL_WRITER
	auto result = writer::wgsl::Generate(&program, options_wgsl_);
	generated_wgsl_ = std::move(result.wgsl);
	if (!result.success) {
	FatalError(program.Diagnostics(),
	"WGSL writer failed: " + result.error);
	}
	#endif // TINT_BUILD_WGSL_WRITER
	break;
	}
	case OutputFormat::kSpv: {
	#if TINT_BUILD_SPV_WRITER
	auto result = writer::spirv::Generate(&program, options_spirv_);
	generated_spirv_ = std::move(result.spirv);
	if (!result.success) {
	FatalError(program.Diagnostics(),
	"SPIR-V writer failed: " + result.error);
	}
	if (!SPIRVToolsValidationCheck(program, generated_spirv_)) {
	FatalError(program.Diagnostics(),
	"Fuzzing detected invalid spirv being emitted by Tint");
	}

	#endif // TINT_BUILD_SPV_WRITER
	break;
	}
	case OutputFormat::kHLSL: {
	#if TINT_BUILD_HLSL_WRITER
	auto result = writer::hlsl::Generate(&program, options_hlsl_);
	generated_hlsl_ = std::move(result.hlsl);
	if (!result.success) {
	FatalError(program.Diagnostics(),
	"HLSL writer failed: " + result.error);
	}
	#endif // TINT_BUILD_HLSL_WRITER
	break;
	}
	case OutputFormat::kMSL: {
	#if TINT_BUILD_MSL_WRITER
	auto result = writer::msl::Generate(&program, options_msl_);
	generated_msl_ = std::move(result.msl);
	if (!result.success) {
	FatalError(program.Diagnostics(), "MSL writer failed: " + result.error);
	}
	#endif // TINT_BUILD_MSL_WRITER
	break;
	}
	case OutputFormat::kNone:
	break;
	}

	return 0;
	}

	} // namespace fuzzers
	} // namespace tint