Add fuzzer for Vulkan->WebGPU spirv-opt passes (#2626)

Fixes #2622

test/fuzzers/BUILD.gn

@@ -38,6 +38,7 @@ if (!build_with_chromium || use_fuzzing_engine) {
       ":spvtools_opt_performance_fuzzer",
       ":spvtools_opt_size_fuzzer",
       ":spvtools_opt_webgputovulkan_fuzzer",
+      ":spvtools_opt_vulkantowebgpu_fuzzer",
       ":spvtools_val_fuzzer",
     ]
   }
@@ -88,12 +89,19 @@ spvtools_fuzzer("spvtools_opt_size_fuzzer_src") {
   ]
 }
 
+
 spvtools_fuzzer("spvtools_opt_webgputovulkan_fuzzer_src") {
   sources = [
     "spvtools_opt_webgputovulkan_fuzzer.cpp",
   ]
 }
 
+spvtools_fuzzer("spvtools_opt_vulkantowebgpu_fuzzer_src") {
+  sources = [
+    "spvtools_opt_vulkantowebgpu_fuzzer.cpp",
+  ]
+}
+
 spvtools_fuzzer("spvtools_val_fuzzer_src") {
   sources = [
     "spvtools_val_fuzzer.cpp",
@@ -142,6 +150,14 @@ if (!build_with_chromium || use_fuzzing_engine) {
     seed_corpus = "corpora/spv"
   }
 
+  fuzzer_test("spvtools_opt_vulkantowebgpu_fuzzer") {
+    sources = []
+    deps = [
+      ":spvtools_opt_vulkantowebgpu_fuzzer_src",
+    ]
+    seed_corpus = "corpora/spv"
+  }
+
   fuzzer_test("spvtools_val_fuzzer") {
     sources = []
     deps = [

test/fuzzers/spvtools_opt_vulkantowebgpu_fuzzer.cpp

@@ -0,0 +1,38 @@
+// Copyright (c) 2019 Google Inc.
+//
+// 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 <cstdint>
+#include <vector>
+
+#include "spirv-tools/optimizer.hpp"
+
+extern "C" int LLVMFuzzerTestOneInput(const uint8_t* data, size_t size) {
+  spvtools::Optimizer optimizer(SPV_ENV_WEBGPU_0);
+  optimizer.SetMessageConsumer([](spv_message_level_t, const char*,
+                                  const spv_position_t&, const char*) {});
+
+  std::vector<uint32_t> input;
+  input.resize(size >> 2);
+
+  size_t count = 0;
+  for (size_t i = 0; (i + 3) < size; i += 4) {
+    input[count++] = data[i] | (data[i + 1] << 8) | (data[i + 2] << 16) |
+                     (data[i + 3]) << 24;
+  }
+
+  optimizer.RegisterVulkanToWebGPUPasses();
+  optimizer.Run(input.data(), input.size(), &input);
+
+  return 0;
+}