Fully support initializing fuzzer utilities using a seed value

Adds a constructor to TransformBuilder that takes a seed value.
Removes accessing internal details of the fuzzing utilities.
Also a bunch of little clean ups through out the code.

BUG=tint:1261

Change-Id: Iac7ace25b91fa96959e6c07b1df963900a1f7100
Reviewed-on: https://dawn-review.googlesource.com/c/tint/+/67700
Auto-Submit: Ryan Harrison <rharrison@chromium.org>
Kokoro: Kokoro <noreply+kokoro@google.com>
Commit-Queue: Ben Clayton <bclayton@google.com>
Reviewed-by: Ben Clayton <bclayton@google.com>

fuzzers/data_builder.h

@@ -25,18 +25,20 @@
 namespace tint {
 namespace fuzzers {
 
-/// Builder for generic pseudo-random data using a data buffer as seed
+/// Builder for generic pseudo-random data
 class DataBuilder {
  public:
-  /// @brief Initialize internal random number generation using data as seed
-  /// @param data - pointer to a data buffer to use as a seed
+  /// @brief Initializes the internal engine using a seed value
+  /// @param seed - seed value passed to engine
+  explicit DataBuilder(uint64_t seed) : generator_(seed) {}
+
+  /// @brief Initializes the internal engine using seed data
+  /// @param data - data fuzzer to calculate seed from
   /// @param size - size of data buffer
   explicit DataBuilder(const uint8_t* data, size_t size)
-      : generator_(data, size) {}
-
-  /// @brief Initialize internal random number generation using seed value
-  /// @param seed - value to use as seed
-  explicit DataBuilder(uint64_t seed) : generator_(seed) {}
+      : generator_(data, size) {
+    assert(data != nullptr && "|data| must be !nullptr");
+  }
 
   ~DataBuilder() = default;
   DataBuilder(DataBuilder&&) = default;
@@ -131,7 +133,7 @@ class DataBuilder {
       }
       std::vector<uint8_t> source(count);
       b->build(source.data(), count);
-      return std::string(source.begin(), source.end());
+      return {source.begin(), source.end()};
     }
   };
 

fuzzers/random_generator.cc

@@ -59,7 +59,9 @@ size_t HashBuffer(const uint8_t* data, const size_t size) {
 RandomGenerator::RandomGenerator(uint64_t seed) : engine_(seed) {}
 
 RandomGenerator::RandomGenerator(const uint8_t* data, size_t size)
-    : engine_(RandomGenerator::CalculateSeed(data, size)) {}
+    : engine_(RandomGenerator::CalculateSeed(data, size)) {
+  assert(data != nullptr && "|data| must be !nullptr");
+}
 
 uint32_t RandomGenerator::GetUInt32(uint32_t lower, uint32_t upper) {
   return RandomUInt(&engine_, lower, upper);

fuzzers/tint_spv_reader_msl_writer_fuzzer.cc

@@ -21,9 +21,9 @@ namespace tint {
 namespace fuzzers {
 
 extern "C" int LLVMFuzzerTestOneInput(const uint8_t* data, size_t size) {
-  DataBuilder b(data, size);
+  DataBuilder db(data, size);
   writer::msl::Options options;
-  GenerateMslOptions(&b, &options);
+  GenerateMslOptions(&db, &options);
   tint::fuzzers::ReaderWriterFuzzer fuzzer(InputFormat::kSpv,
                                            OutputFormat::kMSL);
   fuzzer.SetOptionsMsl(options);

fuzzers/tint_spv_reader_spv_writer_fuzzer.cc

@@ -21,9 +21,9 @@ namespace tint {
 namespace fuzzers {
 
 extern "C" int LLVMFuzzerTestOneInput(const uint8_t* data, size_t size) {
-  DataBuilder b(data, size);
+  DataBuilder db(data, size);
   writer::spirv::Options options;
-  GenerateSpirvOptions(&b, &options);
+  GenerateSpirvOptions(&db, &options);
   tint::fuzzers::ReaderWriterFuzzer fuzzer(InputFormat::kSpv,
                                            OutputFormat::kSpv);
   fuzzer.SetOptionsSpirv(options);

fuzzers/tint_wgsl_reader_msl_writer_fuzzer.cc

@@ -21,9 +21,9 @@ namespace tint {
 namespace fuzzers {
 
 extern "C" int LLVMFuzzerTestOneInput(const uint8_t* data, size_t size) {
-  DataBuilder b(data, size);
+  DataBuilder db(data, size);
   writer::msl::Options options;
-  GenerateMslOptions(&b, &options);
+  GenerateMslOptions(&db, &options);
   tint::fuzzers::ReaderWriterFuzzer fuzzer(InputFormat::kWGSL,
                                            OutputFormat::kMSL);
   fuzzer.SetOptionsMsl(options);

fuzzers/tint_wgsl_reader_spv_writer_fuzzer.cc

@@ -21,9 +21,9 @@ namespace tint {
 namespace fuzzers {
 
 extern "C" int LLVMFuzzerTestOneInput(const uint8_t* data, size_t size) {
-  DataBuilder b(data, size);
+  DataBuilder db(data, size);
   writer::spirv::Options options;
-  GenerateSpirvOptions(&b, &options);
+  GenerateSpirvOptions(&db, &options);
   tint::fuzzers::ReaderWriterFuzzer fuzzer(InputFormat::kWGSL,
                                            OutputFormat::kSpv);
   fuzzer.SetOptionsSpirv(options);

fuzzers/transform_builder.h

@@ -29,16 +29,22 @@ namespace fuzzers {
 /// manager.
 class TransformBuilder {
  public:
-  /// @brief Initialize the data source using a data buffer as a seed
-  /// @param data - pointer to a data buffer to use as a seed
+  /// @brief Initializes the internal builder using a seed value
+  /// @param seed - seed value passed to engine
+  explicit TransformBuilder(uint64_t seed) : builder_(seed) {}
+
+  /// @brief Initializes the internal builder using seed data
+  /// @param data - data fuzzer to calculate seed from
   /// @param size - size of data buffer
   explicit TransformBuilder(const uint8_t* data, size_t size)
-      : builder_(data, size) {}
-  ~TransformBuilder() {}
+      : builder_(data, size) {
+    assert(data != nullptr && "|data| must be !nullptr");
+  }
+
+  ~TransformBuilder() = default;
 
   transform::Manager* manager() { return &manager_; }
   transform::DataMap* data_map() { return &data_map_; }
-  DataBuilder* builder() { return &builder_; }
 
   /// Adds a transform and needed data to |manager_| and |data_map_|.
   /// @tparam T - A class that inherits from transform::Transform and has an
@@ -66,6 +72,8 @@ class TransformBuilder {
   transform::Manager manager_;
   transform::DataMap data_map_;
 
+  DataBuilder* builder() { return &builder_; }
+
   /// Implementation of AddTransform, specialized for each transform that is
   /// implemented. Default implementation intentionally deleted to cause compile
   /// error if unimplemented type passed in.