Create common utility class for fuzzing

This moves the usage of Tint in the fuzzers into a single class. This
will be expanded in the future to support emitting shaders, so fuzzing
tests, just need to indicate which reader & writer they want to use,
instead of having each test implement all of the API usage logic
directly.

BUG=tint:199

Change-Id: Id081a374014b7640a07b267e544ddeba3e6329dd
Reviewed-on: https://dawn-review.googlesource.com/c/tint/+/36760
Commit-Queue: dan sinclair <dsinclair@chromium.org>
Reviewed-by: dan sinclair <dsinclair@chromium.org>
Auto-Submit: Ryan Harrison <rharrison@chromium.org>

BUILD.gn

@@ -1308,6 +1308,10 @@ if (build_with_chromium) {
   source_set("tint_fuzzer_common") {
     configs += [ ":tint_common_config" ]
     public_configs = [ ":tint_public_config" ]
+    sources = [
+      "fuzzers/tint_common_fuzzer.cc",
+      "fuzzers/tint_common_fuzzer.h",
+    ]
   }
 
   if (tint_build_wgsl_reader) {

fuzzers/CMakeLists.txt

@@ -13,7 +13,9 @@
 # limitations under the License.
 
 function(add_tint_fuzzer NAME)
-  add_executable(${NAME} ${NAME}.cc)
+  add_executable(${NAME}
+    ${NAME}.cc
+    tint_common_fuzzer.cc)
   target_link_libraries(${NAME} libtint-fuzz)
   tint_default_compile_options(${NAME})
   target_compile_options(${NAME} PRIVATE -Wno-missing-prototypes)

fuzzers/tint_common_fuzzer.cc

@@ -0,0 +1,69 @@
+// 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 <memory>
+#include <string>
+#include <vector>
+
+namespace tint {
+namespace fuzzers {
+
+CommonFuzzer::CommonFuzzer(InputFormat input) : input_(input) {}
+CommonFuzzer::~CommonFuzzer() = default;
+
+int CommonFuzzer::Run(const uint8_t* data, size_t size) {
+  std::unique_ptr<tint::reader::Reader> parser;
+#if TINT_BUILD_WGSL_READER
+  std::unique_ptr<tint::Source::File> file;
+#endif  // TINT_BUILD_WGSL_READER
+
+  switch (input_) {
+    case InputFormat::kWGSL:
+#if TINT_BUILD_WGSL_READER
+    {
+      std::string str(reinterpret_cast<const char*>(data), size);
+
+      file = std::make_unique<tint::Source::File>("test.wgsl", str);
+      parser = std::make_unique<tint::reader::wgsl::Parser>(file.get());
+    }
+#endif  // TINT_BUILD_WGSL_READER
+    break;
+    case InputFormat::kSpv:
+#if TINT_BUILD_SPV_READER
+    {
+      size_t sizeInU32 = size / sizeof(uint32_t);
+      const uint32_t* u32Data = reinterpret_cast<const uint32_t*>(data);
+      std::vector<uint32_t> input(u32Data, u32Data + sizeInU32);
+
+      if (input.size() != 0) {
+        parser = std::make_unique<tint::reader::spirv::Parser>(input);
+      }
+    }
+#endif  // TINT_BUILD_WGSL_READER
+    break;
+    default:
+      break;
+  }
+
+  if (parser) {
+    parser->Parse();
+  }
+
+  return 0;
+}
+
+}  // namespace fuzzers
+}  // namespace tint

fuzzers/tint_common_fuzzer.h

@@ -0,0 +1,39 @@
+// 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.
+
+#ifndef FUZZERS_TINT_COMMON_FUZZER_H_
+#define FUZZERS_TINT_COMMON_FUZZER_H_
+
+#include "include/tint/tint.h"
+
+namespace tint {
+namespace fuzzers {
+
+enum class InputFormat { kWGSL, kSpv, kNone };
+
+class CommonFuzzer {
+ public:
+  explicit CommonFuzzer(InputFormat input);
+  ~CommonFuzzer();
+
+  int Run(const uint8_t* data, size_t size);
+
+ private:
+  InputFormat input_;
+};
+
+}  // namespace fuzzers
+}  // namespace tint
+
+#endif  // FUZZERS_TINT_COMMON_FUZZER_H_

fuzzers/tint_spv_reader_fuzzer.cc

@@ -14,17 +14,9 @@
 
 #include <vector>
 
-#include "src/reader/spirv/parser.h"
+#include "fuzzers/tint_common_fuzzer.h"
 
 extern "C" int LLVMFuzzerTestOneInput(const uint8_t* data, size_t size) {
-  size_t sizeInU32 = size / sizeof(uint32_t);
-  const uint32_t* u32Data = reinterpret_cast<const uint32_t*>(data);
-  std::vector<uint32_t> input(u32Data, u32Data + sizeInU32);
-
-  if (input.size() != 0) {
-    tint::reader::spirv::Parser parser(input);
-    parser.Parse();
-  }
-
-  return 0;
+  tint::fuzzers::CommonFuzzer fuzzer(tint::fuzzers::InputFormat::kSpv);
+  return fuzzer.Run(data, size);
 }

fuzzers/tint_wgsl_reader_fuzzer.cc

@@ -14,14 +14,9 @@
 
 #include <string>
 
-#include "src/reader/wgsl/parser.h"
+#include "fuzzers/tint_common_fuzzer.h"
 
 extern "C" int LLVMFuzzerTestOneInput(const uint8_t* data, size_t size) {
-  std::string str(reinterpret_cast<const char*>(data), size);
-
-  tint::Source::File file("test.wgsl", str);
-  tint::reader::wgsl::Parser parser(&file);
-  parser.Parse();
-
-  return 0;
+  tint::fuzzers::CommonFuzzer fuzzer(tint::fuzzers::InputFormat::kWGSL);
+  return fuzzer.Run(data, size);
 }