AstValueFactory: Add paranoid null checks for debugging.

src/ast/ast-value-factory.cc

 // Copyright 2014 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 231 matching lines @@
   if (isolate_) result->Internalize(isolate_);
   return result;
 }
 
 
 const AstConsString* AstValueFactory::NewConsString(
     const AstString* left, const AstString* right) {
   // This Vector will be valid as long as the Collector is alive (meaning that
   // the AstRawString will not be moved).
   AstConsString* new_string = new (zone_) AstConsString(left, right);
+  CHECK(new_string != nullptr);
   strings_.Add(new_string);
   if (isolate_) {
     new_string->Internalize(isolate_);
   }
   return new_string;
 }
 
 
 void AstValueFactory::Internalize(Isolate* isolate) {
   if (isolate_) {
     // Everything is already internalized.
     return;
   }
   // Strings need to be internalized before values, because values refer to
   // strings.
   for (int i = 0; i < strings_.length(); ++i) {
     strings_[i]->Internalize(isolate);
   }
   for (int i = 0; i < values_.length(); ++i) {
     values_[i]->Internalize(isolate);
   }
   isolate_ = isolate;
 }
 
 
 const AstValue* AstValueFactory::NewString(const AstRawString* string) {
   AstValue* value = new (zone_) AstValue(string);
-  DCHECK(string != NULL);
+  CHECK(string != nullptr);
   if (isolate_) {
     value->Internalize(isolate_);
   }
   values_.Add(value);
   return value;
 }
 
 
 const AstValue* AstValueFactory::NewSymbol(const char* name) {
   AstValue* value = new (zone_) AstValue(name);
@@ skipping 71 matching lines @@
   // return this AstRawString.
   AstRawString key(is_one_byte, literal_bytes, hash);
   base::HashMap::Entry* entry = string_table_.LookupOrInsert(&key, hash);
   if (entry->value == NULL) {
     // Copy literal contents for later comparison.
     int length = literal_bytes.length();
     byte* new_literal_bytes = zone_->NewArray<byte>(length);
     memcpy(new_literal_bytes, literal_bytes.start(), length);
     AstRawString* new_string = new (zone_) AstRawString(
         is_one_byte, Vector<const byte>(new_literal_bytes, length), hash);
+    CHECK(new_string != nullptr);
     entry->key = new_string;
     strings_.Add(new_string);
     if (isolate_) {
       new_string->Internalize(isolate_);
     }
     entry->value = reinterpret_cast<void*>(1);
   }
   return reinterpret_cast<AstRawString*>(entry->key);
 }
 
@@ skipping 23 matching lines @@
                                   length) == 0;
     } else {
       return CompareCharsUnsigned(reinterpret_cast<const uint16_t*>(l),
                                   reinterpret_cast<const uint16_t*>(r),
                                   length) == 0;
     }
   }
 }
 }  // namespace internal
 }  // namespace v8