[regexp] add fuzzer support for regexp parser and compiler.

test/fuzzer/regexp.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/factory.h"
+#include "src/objects-inl.h"
+#include "src/objects.h"
+#include "src/regexp/jsregexp.h"
+#include "test/fuzzer/fuzzer-support.h"
+
+namespace i = v8::internal;
+
+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::Isolate::Scope isolate_scope(isolate);
+  v8::HandleScope handle_scope(isolate);
+  v8::Context::Scope context_scope(support->GetContext());
+  v8::TryCatch try_catch(isolate);
+
+  i::FLAG_harmony_unicode_regexps = true;
+  i::FLAG_harmony_regexp_lookbehind = true;
+
+  i::Isolate* i_isolate = reinterpret_cast<i::Isolate*>(isolate);
+  i::Factory* factory = i_isolate->factory();
+
+  if (size > INT_MAX) return 0;
+  i::MaybeHandle<i::String> maybe_source = factory->NewStringFromOneByte(
+      i::Vector<const uint8_t>(data, static_cast<int>(size)));
+  i::Handle<i::String> source;
+  if (!maybe_source.ToHandle(&source)) return 0;
+
+  static const int kAllFlags = i::JSRegExp::kGlobal | i::JSRegExp::kIgnoreCase |
+                               i::JSRegExp::kMultiline | i::JSRegExp::kSticky |
+                               i::JSRegExp::kUnicode;
+
+  const uint8_t one_byte_array[6] = {'f', 'o', 'o', 'b', 'a', 'r'};
+  const i::uc16 two_byte_array[6] = {'f', 0xD83D, 0xDCA9, 'b', 'a', 0x2603};
+
+  i::Handle<i::JSArray> results_array = factory->NewJSArray(4);
+  i::Handle<i::String> one_byte =
+      factory->NewStringFromOneByte(i::Vector<const uint8_t>(one_byte_array, 6))
+          .ToHandleChecked();
+  i::Handle<i::String> two_byte =
+      factory->NewStringFromTwoByte(i::Vector<const i::uc16>(two_byte_array, 6))
+          .ToHandleChecked();
+
+  for (int flags = 0; flags <= kAllFlags; flags++) {
+    v8::TryCatch try_catch(isolate);
+    i::MaybeHandle<i::JSRegExp> maybe_regexp =
+        i::JSRegExp::New(source, static_cast<i::JSRegExp::Flags>(flags));
+    i::Handle<i::JSRegExp> regexp;
+    if (!maybe_regexp.ToHandle(&regexp)) continue;
+    USE(i::RegExpImpl::Exec(regexp, one_byte, 0, results_array).is_null() &&
+        i::RegExpImpl::Exec(regexp, two_byte, 0, results_array).is_null());
+  }
+
+  return 0;
+}