convert String::New functions to maybe

R=svenpanne@chromium.org
BUG=v8:3929
LOG=n

Review URL: https://codereview.chromium.org/1010803008

Cr-Commit-Position: refs/heads/master@{#27236}

include/v8.h

@@ -2031,11 +2031,16 @@ class V8_EXPORT Name : public Primitive {
 };
 
 
+enum class NewStringType { kNormal, kInternalized };
+
+
 /**
  * A JavaScript string value (ECMA-262, 4.3.17).
  */
 class V8_EXPORT String : public Name {
  public:
+  static const int kMaxLength = (1 << 28) - 16;
+
   enum Encoding {
     UNKNOWN_ENCODING = 0x1,
     TWO_BYTE_ENCODING = 0x0,
@@ -2232,25 +2237,51 @@ class V8_EXPORT String : public Name {
 
   V8_INLINE static String* Cast(v8::Value* obj);
 
-  enum NewStringType { kNormalString, kInternalizedString };
+  // TODO(dcarney): remove with deprecation of New functions.
+  enum NewStringType {
+    kNormalString = static_cast<int>(v8::NewStringType::kNormal),
+    kInternalizedString = static_cast<int>(v8::NewStringType::kInternalized)
+  };
 
   /** Allocates a new string from UTF-8 data.*/
-  static Local<String> NewFromUtf8(Isolate* isolate, const char* data,
+  static V8_DEPRECATE_SOON(
+      "Use maybe version",
+      Local<String> NewFromUtf8(Isolate* isolate, const char* data,
                                 NewStringType type = kNormalString,
+                                int length = -1));
+
+  /** Allocates a new string from UTF-8 data. Only returns an empty value when
+   * length > kMaxLength. **/
+  static MaybeLocal<String> NewFromUtf8(Isolate* isolate, const char* data,
+                                        v8::NewStringType type,
                                         int length = -1);
 
   /** Allocates a new string from Latin-1 data.*/
-  static Local<String> NewFromOneByte(
-      Isolate* isolate,
-      const uint8_t* data,
+  static V8_DEPRECATE_SOON(
+      "Use maybe version",
+      Local<String> NewFromOneByte(Isolate* isolate, const uint8_t* data,
                                    NewStringType type = kNormalString,
+                                   int length = -1));
+
+  /** Allocates a new string from Latin-1 data.  Only returns an empty value
+   * when length > kMaxLength. **/
+  static MaybeLocal<String> NewFromOneByte(Isolate* isolate,
+                                           const uint8_t* data,
+                                           v8::NewStringType type,
                                            int length = -1);
 
   /** Allocates a new string from UTF-16 data.*/
-  static Local<String> NewFromTwoByte(
-      Isolate* isolate,
-      const uint16_t* data,
+  static V8_DEPRECATE_SOON(
+      "Use maybe version",
+      Local<String> NewFromTwoByte(Isolate* isolate, const uint16_t* data,
                                    NewStringType type = kNormalString,
+                                   int length = -1));
+
+  /** Allocates a new string from UTF-16 data. Only returns an empty value when
+   * length > kMaxLength. **/
+  static MaybeLocal<String> NewFromTwoByte(Isolate* isolate,
+                                           const uint16_t* data,
+                                           v8::NewStringType type,
                                            int length = -1);
 
   /**
@@ -2267,8 +2298,12 @@ class V8_EXPORT String : public Name {
    * should the underlying buffer be deallocated or modified except through the
    * destructor of the external string resource.
    */
-  static Local<String> NewExternal(Isolate* isolate,
-                                   ExternalStringResource* resource);
+  static V8_DEPRECATE_SOON(
+      "Use maybe version",
+      Local<String> NewExternal(Isolate* isolate,
+                                ExternalStringResource* resource));
+  static MaybeLocal<String> NewExternalTwoByte(
+      Isolate* isolate, ExternalStringResource* resource);
 
   /**
    * Associate an external string resource with this string by transforming it
@@ -2289,8 +2324,12 @@ class V8_EXPORT String : public Name {
    * should the underlying buffer be deallocated or modified except through the
    * destructor of the external string resource.
    */
-  static Local<String> NewExternal(Isolate* isolate,
-                                   ExternalOneByteStringResource* resource);
+  static V8_DEPRECATE_SOON(
+      "Use maybe version",
+      Local<String> NewExternal(Isolate* isolate,
+                                ExternalOneByteStringResource* resource));
+  static MaybeLocal<String> NewExternalOneByte(
+      Isolate* isolate, ExternalOneByteStringResource* resource);
 
   /**
    * Associate an external string resource with this string by transforming it

test/cctest/test-api.cc

@@ -694,28 +694,23 @@ class RandomLengthOneByteResource
 
 
 THREADED_TEST(NewExternalForVeryLongString) {
+  auto isolate = CcTest::isolate();
   {
-    LocalContext env;
-    v8::HandleScope scope(env->GetIsolate());
+    v8::HandleScope scope(isolate);
     v8::TryCatch try_catch;
     RandomLengthOneByteResource r(1 << 30);
-    v8::Local<v8::String> str = v8::String::NewExternal(CcTest::isolate(), &r);
+    v8::Local<v8::String> str = v8::String::NewExternal(isolate, &r);
     CHECK(str.IsEmpty());
-    CHECK(try_catch.HasCaught());
-    String::Utf8Value exception_value(try_catch.Exception());
-    CHECK_EQ(0, strcmp("RangeError: Invalid string length", *exception_value));
+    CHECK(!try_catch.HasCaught());
   }
 
   {
-    LocalContext env;
-    v8::HandleScope scope(env->GetIsolate());
+    v8::HandleScope scope(isolate);
     v8::TryCatch try_catch;
     RandomLengthResource r(1 << 30);
-    v8::Local<v8::String> str = v8::String::NewExternal(CcTest::isolate(), &r);
+    v8::Local<v8::String> str = v8::String::NewExternal(isolate, &r);
     CHECK(str.IsEmpty());
-    CHECK(try_catch.HasCaught());
-    String::Utf8Value exception_value(try_catch.Exception());
-    CHECK_EQ(0, strcmp("RangeError: Invalid string length", *exception_value));
+    CHECK(!try_catch.HasCaught());
   }
 }
 
@@ -21618,7 +21613,6 @@ TEST(StreamingScriptWithSourceMappingURLInTheMiddle) {
 TEST(NewStringRangeError) {
   v8::Isolate* isolate = CcTest::isolate();
   v8::HandleScope handle_scope(isolate);
-  LocalContext env;
   const int length = i::String::kMaxLength + 1;
   const int buffer_size = length * sizeof(uint16_t);
   void* buffer = malloc(buffer_size);
@@ -21629,21 +21623,21 @@ TEST(NewStringRangeError) {
     char* data = reinterpret_cast<char*>(buffer);
     CHECK(v8::String::NewFromUtf8(isolate, data, v8::String::kNormalString,
                                   length).IsEmpty());
-    CHECK(try_catch.HasCaught());
+    CHECK(!try_catch.HasCaught());
   }
   {
     v8::TryCatch try_catch;
     uint8_t* data = reinterpret_cast<uint8_t*>(buffer);
     CHECK(v8::String::NewFromOneByte(isolate, data, v8::String::kNormalString,
                                      length).IsEmpty());
-    CHECK(try_catch.HasCaught());
+    CHECK(!try_catch.HasCaught());
   }
   {
     v8::TryCatch try_catch;
     uint16_t* data = reinterpret_cast<uint16_t*>(buffer);
     CHECK(v8::String::NewFromTwoByte(isolate, data, v8::String::kNormalString,
                                      length).IsEmpty());
-    CHECK(try_catch.HasCaught());
+    CHECK(!try_catch.HasCaught());
   }
   free(buffer);
 }