[wasm] Add a new fuzzer which can also test wasm function calls.

test/fuzzer/wasm-call.cc

+// Copyright 2016 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include <stddef.h>
+#include <stdint.h>
+
+#include "include/v8.h"
+#include "src/isolate.h"
+#include "src/objects.h"
+#include "src/wasm/wasm-interpreter.h"
+#include "src/wasm/wasm-module-builder.h"
+#include "src/wasm/wasm-module.h"
+#include "test/common/wasm/test-signatures.h"
+#include "test/common/wasm/wasm-module-runner.h"
+#include "test/fuzzer/fuzzer-support.h"
+
+#define WASM_CODE_FUZZER_HASH_SEED 83
+#define MAX_NUM_FUNCTIONS 3
+#define MAX_NUM_PARAMS 3
+
+#define FUZZER_TYPE_FLOAT32 0
+#define FUZZER_TYPE_FLOAT64 1
+#define FUZZER_TYPE_INT32 2
+#define FUZZER_TYPE_INT64 3
+
+using namespace v8::internal::wasm;
+
+template <typename V>
+static inline V read_value(const uint8_t** data, size_t* size, bool* ok) {
+  // The status flag {ok} checks that the decoding up until now was okay, and
+  // that a value of type V can be read without problems.
+  *ok &= (*size > sizeof(V));
+  if (!(*ok)) return 0;
+  V result = *reinterpret_cast<const V*>(*data);

[titzer, 2016/10/24 11:17:21]

This is not going to work on platforms that don't support misaligned access.

[ahaas, 2016/10/24 12:10:33]

Done.

+  *data += sizeof(V);
+  *size -= sizeof(V);
+  return result;
+}
+
+static void add_argument(
+    v8::internal::Isolate* isolate, uint8_t type, WasmVal* interpreter_args,
+    v8::internal::Handle<v8::internal::Object>* compiled_args, int* argc,
+    const uint8_t** data, size_t* size, bool* ok) {
+  if (!(*ok)) return;
+  switch (type) {
+    case FUZZER_TYPE_FLOAT32: {
+      float value = read_value<float>(data, size, ok);
+      interpreter_args[*argc] = WasmVal(value);
+      compiled_args[*argc] =
+          isolate->factory()->NewNumber(static_cast<double>(value));
+      break;
+    }
+    case FUZZER_TYPE_FLOAT64: {
+      double value = read_value<double>(data, size, ok);
+      interpreter_args[*argc] = WasmVal(value);
+      compiled_args[*argc] = isolate->factory()->NewNumber(value);
+      break;
+    }
+    case FUZZER_TYPE_INT32: {
+      int32_t value = read_value<int32_t>(data, size, ok);
+      interpreter_args[*argc] = WasmVal(value);
+      compiled_args[*argc] =
+          isolate->factory()->NewNumber(static_cast<double>(value));
+      break;
+    }
+    default:
+      UNREACHABLE();
+  }
+  (*argc)++;
+}
+
+extern "C" int LLVMFuzzerTestOneInput(const uint8_t* data, size_t size) {
+  v8_fuzzer::FuzzerSupport* support = v8_fuzzer::FuzzerSupport::Get();
+  v8::Isolate* isolate = support->GetIsolate();
+  v8::internal::Isolate* i_isolate =
+      reinterpret_cast<v8::internal::Isolate*>(isolate);
+
+  // Clear any pending exceptions from a prior run.
+  if (i_isolate->has_pending_exception()) {
+    i_isolate->clear_pending_exception();
+  }
+
+  v8::Isolate::Scope isolate_scope(isolate);
+  v8::HandleScope handle_scope(isolate);
+  v8::Context::Scope context_scope(support->GetContext());
+  v8::TryCatch try_catch(isolate);
+
+  v8::internal::AccountingAllocator allocator;
+  v8::internal::Zone zone(&allocator, ZONE_NAME);
+
+  bool ok = true;
+  uint8_t num_functions =
+      (read_value<uint8_t>(&data, &size, &ok) % MAX_NUM_FUNCTIONS) + 1;
+
+  LocalType types[] = {kAstF32, kAstF64, kAstI32, kAstI64};

[titzer, 2016/10/24 11:17:21]

Why not just make this global and remove WASM_FUZZER_TYPE*

[ahaas, 2016/10/24 12:10:33]

I used the WASM_FUZZER_TYPE* definitions to give names to the type in
{add_argument}. I achieve that now by passing a LocalType to {add_argument}.

+  WasmVal interpreter_args[3];
+  v8::internal::Handle<v8::internal::Object> compiled_args[3];
+  int argc = 0;
+
+  WasmModuleBuilder builder(&zone);
+  for (int fun = 0; fun < num_functions; fun++) {
+    size_t num_params = static_cast<size_t>(
+        (read_value<uint8_t>(&data, &size, &ok) % MAX_NUM_PARAMS) + 1);
+    FunctionSig::Builder sig_builder(&zone, 1, num_params);
+    sig_builder.AddReturn(kAstI32);
+    for (size_t param = 0; param < num_params; param++) {
+      // The main function cannot handle int64 parameters.
+      uint8_t param_type = (read_value<uint8_t>(&data, &size, &ok) %
+                            (arraysize(types) - (fun == 0 ? 1 : 0)));
+      sig_builder.AddParam(types[param_type]);
+      if (fun == 0) {
+        add_argument(i_isolate, param_type, interpreter_args, compiled_args,
+                     &argc, &data, &size, &ok);
+      }
+    }
+    v8::internal::wasm::WasmFunctionBuilder* f =
+        builder.AddFunction(sig_builder.Build());
+    uint32_t code_size = static_cast<uint32_t>(size / num_functions);
+    f->EmitCode(data, code_size);
+    data += code_size;
+    size -= code_size;
+    if (fun == 0) {
+      f->ExportAs(v8::internal::CStrVector("main"));
+    }
+  }
+
+  ZoneBuffer buffer(&zone);
+  builder.WriteTo(buffer);
+
+  if (!ok) {
+    // The input data was too short.
+    return 0;
+  }
+
+  v8::internal::wasm::testing::SetupIsolateForWasmModule(i_isolate);
+
+  v8::internal::HandleScope scope(i_isolate);
+
+  ErrorThrower interpreter_thrower(i_isolate, "Interpreter");
+  std::unique_ptr<const WasmModule> module(testing::DecodeWasmModuleForTesting(
+      i_isolate, &interpreter_thrower, buffer.begin(), buffer.end(),
+      v8::internal::wasm::ModuleOrigin::kWasmOrigin));
+
+  if (module == nullptr) {
+    return 0;
+  }
+  int32_t result_interpreted;
+  bool possible_nondeterminism = false;
+  {
+    result_interpreted = testing::InterpretWasmModule(
+        i_isolate, &interpreter_thrower, module.get(), 0, interpreter_args,
+        &possible_nondeterminism);
+  }
+
+  ErrorThrower compiler_thrower(i_isolate, "Compiler");
+  v8::internal::Handle<v8::internal::JSObject> instance =
+      testing::InstantiateModuleForTesting(i_isolate, &compiler_thrower,
+                                           module.get());
+
+  if (!interpreter_thrower.error()) {
+    CHECK(!instance.is_null());
+  } else {
+    return 0;
+  }
+  int32_t result_compiled;
+  {
+    result_compiled = testing::CallWasmFunctionForTesting(
+        i_isolate, instance, &compiler_thrower, "main", argc, compiled_args,
+        v8::internal::wasm::ModuleOrigin::kWasmOrigin);
+  }
+  if (result_interpreted == 0xdeadbeef) {
+    CHECK(i_isolate->has_pending_exception());
+    i_isolate->clear_pending_exception();
+  } else {
+    // The WebAssembly spec allows the sign bit of NaN to be non-deterministic.
+    // This sign bit may cause result_interpreted to be different than
+    // result_compiled. Therefore we do not check the equality of the results
+    // if the execution may have produced a NaN at some point.
+    if (!possible_nondeterminism && (result_interpreted != result_compiled)) {
+      V8_Fatal(__FILE__, __LINE__, "WasmCodeFuzzerHash=%x",
+               v8::internal::StringHasher::HashSequentialString(
+                   data, static_cast<int>(size), WASM_CODE_FUZZER_HASH_SEED));
+    }
+  }
+  return 0;
+}