[regexp] Extract code to regexp-utils.{h,cc}

src/regexp/regexp-utils.cc

Index: src/regexp/regexp-utils.cc
diff --git a/src/regexp/regexp-utils.cc b/src/regexp/regexp-utils.cc
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index 0000000000000000000000000000000000000000..8de904b72b7883192463c502a2c56d1245c285ca
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+++ b/src/regexp/regexp-utils.cc
@@ -0,0 +1,230 @@
+// 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 "src/regexp/regexp-utils.h"
+
+#include "src/factory.h"
+#include "src/isolate.h"
+#include "src/objects-inl.h"
+#include "src/regexp/jsregexp.h"
+
+namespace v8 {
+namespace internal {
+
+// Constants for accessing RegExpLastMatchInfo.
+// TODO(jgruber): Currently, RegExpLastMatchInfo is still a JSObject maintained
+// and accessed from JS. This is a crutch until all RegExp logic is ported, then
+// we can take care of RegExpLastMatchInfo.
+
+Handle<Object> RegExpUtils::GetLastMatchField(Isolate* isolate,
+                                              Handle<JSObject> match_info,
+                                              int index) {
+  return JSReceiver::GetElement(isolate, match_info, index).ToHandleChecked();
+}
+
+void RegExpUtils::SetLastMatchField(Isolate* isolate,
+                                    Handle<JSObject> match_info, int index,
+                                    Handle<Object> value) {
+  JSReceiver::SetElement(isolate, match_info, index, value, SLOPPY)
+      .ToHandleChecked();
+}
+
+int RegExpUtils::GetLastMatchNumberOfCaptures(Isolate* isolate,
+                                              Handle<JSObject> match_info) {
+  Handle<Object> obj =
+      GetLastMatchField(isolate, match_info, RegExpImpl::kLastCaptureCount);
+  return Handle<Smi>::cast(obj)->value();
+}
+
+Handle<String> RegExpUtils::GetLastMatchSubject(Isolate* isolate,
+                                                Handle<JSObject> match_info) {
+  return Handle<String>::cast(
+      GetLastMatchField(isolate, match_info, RegExpImpl::kLastSubject));
+}
+
+Handle<Object> RegExpUtils::GetLastMatchInput(Isolate* isolate,
+                                              Handle<JSObject> match_info) {
+  return GetLastMatchField(isolate, match_info, RegExpImpl::kLastInput);
+}
+
+int RegExpUtils::GetLastMatchCapture(Isolate* isolate,
+                                     Handle<JSObject> match_info, int i) {
+  Handle<Object> obj =
+      GetLastMatchField(isolate, match_info, RegExpImpl::kFirstCapture + i);
+  return Handle<Smi>::cast(obj)->value();
+}
+
+Handle<String> RegExpUtils::GenericCaptureGetter(Isolate* isolate,
+                                                 Handle<JSObject> match_info,
+                                                 int capture, bool* ok) {
+  const int index = capture * 2;
+  if (index >= GetLastMatchNumberOfCaptures(isolate, match_info)) {
+    if (ok != nullptr) *ok = false;
+    return isolate->factory()->empty_string();
+  }
+
+  const int match_start = GetLastMatchCapture(isolate, match_info, index);
+  const int match_end = GetLastMatchCapture(isolate, match_info, index + 1);
+  if (match_start == -1 || match_end == -1) {
+    if (ok != nullptr) *ok = false;
+    return isolate->factory()->empty_string();
+  }
+
+  if (ok != nullptr) *ok = true;
+  Handle<String> last_subject = GetLastMatchSubject(isolate, match_info);
+  return isolate->factory()->NewSubString(last_subject, match_start, match_end);
+}
+
+namespace {
+
+V8_INLINE bool HasInitialRegExpMap(Isolate* isolate, Handle<JSReceiver> recv) {
+  return recv->map() == isolate->regexp_function()->initial_map();
+}
+
+}  // namespace
+
+MaybeHandle<Object> RegExpUtils::SetLastIndex(Isolate* isolate,
+                                              Handle<JSReceiver> recv,
+                                              int value) {
+  if (HasInitialRegExpMap(isolate, recv)) {
+    JSRegExp::cast(*recv)->SetLastIndex(value);
+    return recv;
+  } else {
+    return Object::SetProperty(recv, isolate->factory()->lastIndex_string(),
+                               handle(Smi::FromInt(value), isolate), STRICT);
+  }
+}
+
+MaybeHandle<Object> RegExpUtils::GetLastIndex(Isolate* isolate,
+                                              Handle<JSReceiver> recv) {
+  if (HasInitialRegExpMap(isolate, recv)) {
+    return handle(JSRegExp::cast(*recv)->LastIndex(), isolate);
+  } else {
+    return Object::GetProperty(recv, isolate->factory()->lastIndex_string());
+  }
+}
+
+// ES#sec-regexpexec Runtime Semantics: RegExpExec ( R, S )
+// Also takes an optional exec method in case our caller
+// has already fetched exec.
+MaybeHandle<Object> RegExpUtils::RegExpExec(Isolate* isolate,
+                                            Handle<JSReceiver> regexp,
+                                            Handle<String> string,
+                                            Handle<Object> exec) {
+  if (exec->IsUndefined(isolate)) {
+    ASSIGN_RETURN_ON_EXCEPTION(
+        isolate, exec,
+        Object::GetProperty(
+            regexp, isolate->factory()->NewStringFromAsciiChecked("exec")),
+        Object);
+  }
+
+  if (exec->IsCallable()) {
+    const int argc = 1;
+    ScopedVector<Handle<Object>> argv(argc);
+    argv[0] = string;
+
+    Handle<Object> result;
+    ASSIGN_RETURN_ON_EXCEPTION(
+        isolate, result,
+        Execution::Call(isolate, exec, regexp, argc, argv.start()), Object);
+
+    if (!result->IsJSReceiver() && !result->IsNull(isolate)) {
+      THROW_NEW_ERROR(isolate,
+                      NewTypeError(MessageTemplate::kInvalidRegExpExecResult),
+                      Object);
+    }
+    return result;
+  }
+
+  if (!regexp->IsJSRegExp()) {
+    THROW_NEW_ERROR(isolate,
+                    NewTypeError(MessageTemplate::kIncompatibleMethodReceiver,
+                                 isolate->factory()->NewStringFromAsciiChecked(
+                                     "RegExp.prototype.exec"),
+                                 regexp),
+                    Object);
+  }
+
+  {
+    Handle<JSFunction> regexp_exec = isolate->regexp_exec_function();
+
+    const int argc = 1;
+    ScopedVector<Handle<Object>> argv(argc);
+    argv[0] = string;
+
+    return Execution::Call(isolate, exec, regexp_exec, argc, argv.start());
+  }
+}
+
+Maybe<bool> RegExpUtils::IsRegExp(Isolate* isolate, Handle<Object> object) {
+  if (!object->IsJSReceiver()) return Just(false);
+
+  Handle<JSReceiver> receiver = Handle<JSReceiver>::cast(object);
+
+  if (isolate->regexp_function()->initial_map() == receiver->map()) {
+    // Fast-path for unmodified JSRegExp instances.
+    // TODO(ishell): Adapt for new fast-path logic.
+    return Just(true);
+  }
+
+  Handle<Object> match;
+  ASSIGN_RETURN_ON_EXCEPTION_VALUE(
+      isolate, match,
+      JSObject::GetProperty(receiver, isolate->factory()->match_symbol()),
+      Nothing<bool>());
+
+  if (!match->IsUndefined(isolate)) return Just(match->BooleanValue());
+  return Just(object->IsJSRegExp());
+}
+
+bool RegExpUtils::IsBuiltinExec(Handle<Object> exec) {
+  if (!exec->IsJSFunction()) return false;
+
+  Code* code = Handle<JSFunction>::cast(exec)->code();
+  if (code == nullptr) return false;
+
+  return (code->builtin_index() == Builtins::kRegExpPrototypeExec);
+}
+
+// ES#sec-advancestringindex
+// AdvanceStringIndex ( S, index, unicode )
+int RegExpUtils::AdvanceStringIndex(Isolate* isolate, Handle<String> string,
+                                    int index, bool unicode) {
+  int increment = 1;
+
+  if (unicode && index < string->length()) {
+    const uint16_t first = string->Get(index);
+    if (first >= 0xD800 && first <= 0xDBFF && string->length() > index + 1) {
+      const uint16_t second = string->Get(index + 1);
+      if (second >= 0xDC00 && second <= 0xDFFF) {
+        increment = 2;
+      }
+    }
+  }
+
+  return increment;
+}
+
+MaybeHandle<Object> RegExpUtils::SetAdvancedStringIndex(
+    Isolate* isolate, Handle<JSReceiver> regexp, Handle<String> string,
+    bool unicode) {
+  Handle<Object> last_index_obj;
+  ASSIGN_RETURN_ON_EXCEPTION(
+      isolate, last_index_obj,
+      Object::GetProperty(regexp, isolate->factory()->lastIndex_string()),
+      Object);
+
+  ASSIGN_RETURN_ON_EXCEPTION(isolate, last_index_obj,
+                             Object::ToLength(isolate, last_index_obj), Object);
+
+  const int last_index = Handle<Smi>::cast(last_index_obj)->value();
+  const int new_last_index =
+      last_index + AdvanceStringIndex(isolate, string, last_index, unicode);
+
+  return SetLastIndex(isolate, regexp, new_last_index);
+}
+
+}  // namespace internal
+}  // namespace v8