Add API call that identifies strings that are guaranteed

test/cctest/test-api.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 5752 matching lines @@
     int len) {
   Local<v8::Array> a =
       Local<v8::Array>::Cast(context->Global()->Get(v8_str(name)));
   Local<v8::Array> alens =
       Local<v8::Array>::Cast(context->Global()->Get(v8_str(lengths_name)));
   for (int i = 0; i < len; i++) {
     Local<v8::String> string =
       Local<v8::String>::Cast(a->Get(i));
     Local<v8::Number> expected_len =
       Local<v8::Number>::Cast(alens->Get(i));
+    CHECK_EQ((expected_len->Value() != string->Length()),
+          string->MayContainNonAscii());

[fschneider, 2012/03/19 08:46:31]

Fix indentation here.

[Erik Corry, 2012/03/19 09:51:02]

Done.

     int length = GetUtf8Length(string);
     CHECK_EQ(static_cast<int>(expected_len->Value()), length);
   }
 }
 
 
 static uint16_t StringGet(Handle<String> str, int index) {
   i::Handle<i::String> istring =
       v8::Utils::OpenHandle(String::Cast(*str));
   return istring->Get(index);
@@ skipping 6137 matching lines @@
         FACTORY->NewExternalStringFromAscii(&ascii_resource)));
 
     env->Global()->Set(v8_str("lhs"), lhs);
     env->Global()->Set(v8_str("rhs"), rhs);
 
     CompileRun(
         "var cons = lhs + rhs;"
         "var slice = lhs.substring(1, lhs.length - 1);"
         "var slice_on_cons = (lhs + rhs).substring(1, lhs.length *2 - 1);");
 
+    CHECK(!lhs->MayContainNonAscii());
+    CHECK(!rhs->MayContainNonAscii());
+
     MorphAString(*v8::Utils::OpenHandle(*lhs), &ascii_resource, &uc16_resource);
     MorphAString(*v8::Utils::OpenHandle(*rhs), &ascii_resource, &uc16_resource);
 
     // This should UTF-8 without flattening, since everything is ASCII.
     Handle<String> cons = v8_compile("cons")->Run().As<String>();
     CHECK_EQ(128, cons->Utf8Length());
     int nchars = -1;
     CHECK_EQ(129, cons->WriteUtf8(utf_buffer, -1, &nchars));
     CHECK_EQ(128, nchars);
     CHECK_EQ(0, strcmp(
@@ skipping 4443 matching lines @@
 
 TEST(SecondaryStubCache) {
   StubCacheHelper(true);
 }
 
 
 TEST(PrimaryStubCache) {
   StubCacheHelper(false);
 }