Enable ThreadRestrictionVerifier for StringImpl

third_party/WebKit/Source/wtf/text/StringImpl.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2001 Dirk Mueller ( mueller@kde.org )
  * Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2013 Apple Inc. All
  * rights reserved.
  * Copyright (C) 2006 Andrew Wellington (proton@wiretapped.net)
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
@@ skipping 36 matching lines @@
 #include "wtf/ThreadingPrimitives.h"
 #include <unistd.h>
 #endif
 
 using namespace std;
 
 namespace WTF {
 
 using namespace Unicode;
 
+#if !DCHECK_IS_ON()
 static_assert(sizeof(StringImpl) == 3 * sizeof(int),
               "StringImpl should stay small");
+#endif
 
 #ifdef STRING_STATS
 
 static Mutex& statsMutex() {
   DEFINE_STATIC_LOCAL(Mutex, mutex, ());
   return mutex;
 }
 
 static HashSet<void*>& liveStrings() {
   // Notice that we can't use HashSet<StringImpl*> because then HashSet would
@@ skipping 248 matching lines @@
     return true;
   // AtomicStrings are not safe to send between threads as ~StringImpl()
   // will try to remove them from the wrong AtomicStringTable.
   if (isAtomic())
     return false;
   if (hasOneRef())
     return true;
   return false;
 }
 
+#if DCHECK_IS_ON()
+std::string StringImpl::asciiForDebugging() const {
+  const unsigned kMaxCheckLength = 64;
+  std::string debugString;
+  for (unsigned i = 0; i < length() && i < kMaxCheckLength; ++i) {
+    UChar c = (*this)[i];
+    debugString.push_back(isASCIIPrintable(c) ? c : '?');
+  }
+  return debugString;

[esprehn, 2017/01/11 22:34:01]

This function can be:

CString ascii = left(64).ascii();
return std::string(ascii.data(), ascii.length());

[Charlie Harrison, 2017/01/12 16:42:30]

Ah right, for some reason I was concerned with pulling in CString here but I
forget why.

[Charlie Harrison, 2017/01/12 22:50:08]

Actually, left is a function of String, so it would have to be
String(this).left(..)...

Unfortunately unless we const_cast this we'll lose the const correctness of
hasOneRef(). I've changed it to use isolatedCopy().

+}
+#endif
+
 PassRefPtr<StringImpl> StringImpl::createUninitialized(unsigned length,
                                                        LChar*& data) {
   if (!length) {
     data = 0;
     return empty();
   }
 
   // Allocate a single buffer large enough to contain the StringImpl
   // struct as well as the data which it contains. This removes one
   // heap allocation from this call.
@@ skipping 1840 matching lines @@
     } else if (localeIdMatchesLang(localeIdentifier, "lt")) {
       // TODO(rob.buis) implement upper-casing rules for lt
       // like in StringImpl::upper(locale).
     }
   }
 
   return toUpper(c);
 }
 
 }  // namespace WTF