[wasm] "Vectorize" fuzzer

Instead of passing {uint8_t*, size_t} pairs as arguments, pass
{Vector<uint8_t>}. This is less error prone and {Vector} provides some
helpful methods.

R=ahaas@chromium.org

Bug: v8:7754
Change-Id: I7469054774618e0bd5c9d38501759b1b2c51d104
Reviewed-on: https://chromium-review.googlesource.com/1134773Reviewed-by: Andreas Haas <ahaas@chromium.org>
Commit-Queue: Clemens Hammacher <clemensh@chromium.org>
Cr-Commit-Position: refs/heads/master@{#54406}

src/vector.h

@@ -123,11 +123,18 @@ class Vector {
     length_ = 0;
   }
 
-  inline Vector<T> operator+(size_t offset) {
+  Vector<T> operator+(size_t offset) {
     DCHECK_LE(offset, length_);
     return Vector<T>(start_ + offset, length_ - offset);
   }
 
+  Vector<T> operator+=(size_t offset) {
+    DCHECK_LE(offset, length_);
+    start_ += offset;
+    length_ -= offset;
+    return *this;
+  }
+
   // Implicit conversion from Vector<T> to Vector<const T>.
   inline operator Vector<const T>() { return Vector<const T>::cast(*this); }
 

test/fuzzer/wasm-code.cc

@@ -20,14 +20,14 @@ namespace fuzzer {
 
 class WasmCodeFuzzer : public WasmExecutionFuzzer {
   bool GenerateModule(
-      Isolate* isolate, Zone* zone, const uint8_t* data, size_t size,
+      Isolate* isolate, Zone* zone, Vector<const uint8_t> data,
       ZoneBuffer& buffer, int32_t& num_args,
       std::unique_ptr<WasmValue[]>& interpreter_args,
       std::unique_ptr<Handle<Object>[]>& compiler_args) override {
     TestSignatures sigs;
     WasmModuleBuilder builder(zone);
     WasmFunctionBuilder* f = builder.AddFunction(sigs.i_iii());
-    f->EmitCode(data, static_cast<uint32_t>(size));
+    f->EmitCode(data.start(), static_cast<uint32_t>(data.size()));
     uint8_t end_opcode = kExprEnd;
     f->EmitCode(&end_opcode, 1);
     builder.AddExport(CStrVector("main"), f);
@@ -46,7 +46,7 @@ class WasmCodeFuzzer : public WasmExecutionFuzzer {
 };
 
 extern "C" int LLVMFuzzerTestOneInput(const uint8_t* data, size_t size) {
-  return WasmCodeFuzzer().FuzzWasmModule(data, size);
+  return WasmCodeFuzzer().FuzzWasmModule({data, size});
 }
 
 }  // namespace fuzzer

test/fuzzer/wasm-compile.cc

@@ -34,35 +34,28 @@ constexpr int kMaxFunctions = 4;
 constexpr int kMaxGlobals = 64;
 
 class DataRange {
-  const uint8_t* data_;
-  size_t size_;
+  Vector<const uint8_t> data_;
 
  public:
-  DataRange(const uint8_t* data, size_t size) : data_(data), size_(size) {}
+  explicit DataRange(Vector<const uint8_t> data) : data_(data) {}
 
   // Don't accidentally pass DataRange by value. This will reuse bytes and might
   // lead to OOM because the end might not be reached.
   // Define move constructor and move assignment, disallow copy constructor and
   // copy assignment (below).
-  DataRange(DataRange&& other) : DataRange(other.data_, other.size_) {
-    other.data_ = nullptr;
-    other.size_ = 0;
-  }
+  DataRange(DataRange&& other) : DataRange(other.data_) { other.data_ = {}; }
   DataRange& operator=(DataRange&& other) {
     data_ = other.data_;
-    size_ = other.size_;
-    other.data_ = nullptr;
-    other.size_ = 0;
+    other.data_ = {};
     return *this;
   }
 
-  size_t size() const { return size_; }
+  size_t size() const { return data_.size(); }
 
   DataRange split() {
-    uint16_t num_bytes = get<uint16_t>() % std::max(size_t{1}, size_);
-    DataRange split(data_, num_bytes);
+    uint16_t num_bytes = get<uint16_t>() % std::max(size_t{1}, data_.size());
+    DataRange split(data_.SubVector(0, num_bytes));
     data_ += num_bytes;
-    size_ -= num_bytes;
     return split;
   }
 
@@ -73,11 +66,10 @@ class DataRange {
     // okay if we don't have a full four bytes available, we'll just use what
     // we have. We aren't concerned about endianness because we are generating
     // arbitrary expressions.
-    const size_t num_bytes = std::min(sizeof(T), size_);
+    const size_t num_bytes = std::min(sizeof(T), data_.size());
     T result = T();
-    memcpy(&result, data_, num_bytes);
+    memcpy(&result, data_.start(), num_bytes);
     data_ += num_bytes;
-    size_ -= num_bytes;
     return result;
   }
 
@@ -751,7 +743,7 @@ FunctionSig* GenerateSig(Zone* zone, DataRange& data) {
 
 class WasmCompileFuzzer : public WasmExecutionFuzzer {
   bool GenerateModule(
-      Isolate* isolate, Zone* zone, const uint8_t* data, size_t size,
+      Isolate* isolate, Zone* zone, Vector<const uint8_t> data,
       ZoneBuffer& buffer, int32_t& num_args,
       std::unique_ptr<WasmValue[]>& interpreter_args,
       std::unique_ptr<Handle<Object>[]>& compiler_args) override {
@@ -759,7 +751,7 @@ class WasmCompileFuzzer : public WasmExecutionFuzzer {
 
     WasmModuleBuilder builder(zone);
 
-    DataRange range(data, static_cast<uint32_t>(size));
+    DataRange range(data);
     std::vector<FunctionSig*> function_signatures;
     function_signatures.push_back(sigs.i_iii());
 
@@ -819,7 +811,7 @@ class WasmCompileFuzzer : public WasmExecutionFuzzer {
 
 extern "C" int LLVMFuzzerTestOneInput(const uint8_t* data, size_t size) {
   constexpr bool require_valid = true;
-  return WasmCompileFuzzer().FuzzWasmModule(data, size, require_valid);
+  return WasmCompileFuzzer().FuzzWasmModule({data, size}, require_valid);
 }
 
 }  // namespace fuzzer

test/fuzzer/wasm-fuzzer-common.cc

@@ -247,7 +247,7 @@ void GenerateTestCase(Isolate* isolate, ModuleWireBytes wire_bytes,
   os << "})();\n";
 }
 
-int WasmExecutionFuzzer::FuzzWasmModule(const uint8_t* data, size_t size,
+int WasmExecutionFuzzer::FuzzWasmModule(Vector<const uint8_t> data,
                                         bool require_valid) {
   v8_fuzzer::FuzzerSupport* support = v8_fuzzer::FuzzerSupport::Get();
   v8::Isolate* isolate = support->GetIsolate();
@@ -269,7 +269,7 @@ int WasmExecutionFuzzer::FuzzWasmModule(const uint8_t* data, size_t size,
   int32_t num_args = 0;
   std::unique_ptr<WasmValue[]> interpreter_args;
   std::unique_ptr<Handle<Object>[]> compiler_args;
-  if (!GenerateModule(i_isolate, &zone, data, size, buffer, num_args,
+  if (!GenerateModule(i_isolate, &zone, data, buffer, num_args,
                       interpreter_args, compiler_args)) {
     return 0;
   }

test/fuzzer/wasm-fuzzer-common.h

@@ -32,12 +32,11 @@ void GenerateTestCase(Isolate* isolate, ModuleWireBytes wire_bytes,
 class WasmExecutionFuzzer {
  public:
   virtual ~WasmExecutionFuzzer() {}
-  int FuzzWasmModule(const uint8_t* data, size_t size,
-                     bool require_valid = false);
+  int FuzzWasmModule(Vector<const uint8_t> data, bool require_valid = false);
 
  protected:
   virtual bool GenerateModule(
-      Isolate* isolate, Zone* zone, const uint8_t* data, size_t size,
+      Isolate* isolate, Zone* zone, Vector<const uint8_t> data,
       ZoneBuffer& buffer, int32_t& num_args,
       std::unique_ptr<WasmValue[]>& interpreter_args,
       std::unique_ptr<Handle<Object>[]>& compiler_args) = 0;