Narrow String::CharAt from int32_t to uint16_t.

runtime/vm/object.h

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #ifndef VM_OBJECT_H_
 #define VM_OBJECT_H_
 
 #include "include/dart_api.h"
 #include "platform/assert.h"
 #include "platform/utils.h"
@@ skipping 5506 matching lines @@
     intptr_t result = Smi::Value(symbol->ptr()->hash_);
     ASSERT(result != 0);
     return result;
   }
 
   // Returns the hash of str1 + str2.
   static intptr_t HashConcat(const String& str1, const String& str2);
 
   virtual RawObject* HashCode() const { return Integer::New(Hash()); }
 
-  int32_t CharAt(intptr_t index) const;
+  uint16_t CharAt(intptr_t index) const;
 
   Scanner::CharAtFunc CharAtFunc() const;
 
   intptr_t CharSize() const;
 
   inline bool Equals(const String& str) const;
   inline bool Equals(const String& str,
                      intptr_t begin_index,  // begin index on 'str'.
                      intptr_t len) const;  // len on 'str'.
 
@@ skipping 209 matching lines @@
   friend class TwoByteString;
   friend class ExternalOneByteString;
   friend class ExternalTwoByteString;
   // So that the MarkingVisitor can print a debug string from a NoHandleScope.
   friend class MarkingVisitor;
 };
 
 
 class OneByteString : public AllStatic {
  public:
-  static int32_t CharAt(const String& str, intptr_t index) {
+  static uint16_t CharAt(const String& str, intptr_t index) {
     return *CharAddr(str, index);
   }
 
-  static void SetCharAt(const String& str, intptr_t index, uint8_t code_point) {
-    *CharAddr(str, index) = code_point;
+  static void SetCharAt(const String& str, intptr_t index, uint8_t code_unit) {
+    *CharAddr(str, index) = code_unit;
   }
   static RawOneByteString* EscapeSpecialCharacters(const String& str);
   // We use the same maximum elements for all strings.
   static const intptr_t kBytesPerElement = 1;
   static const intptr_t kMaxElements = String::kMaxElements;
 
   static intptr_t data_offset() {
     return OFFSET_OF_RETURNED_VALUE(RawOneByteString, data);
   }
 
@@ skipping 103 matching lines @@
   friend class Class;
   friend class String;
   friend class ExternalOneByteString;
   friend class SnapshotReader;
   friend class StringHasher;
 };
 
 
 class TwoByteString : public AllStatic {
  public:
-  static int32_t CharAt(const String& str, intptr_t index) {
+  static uint16_t CharAt(const String& str, intptr_t index) {
     return *CharAddr(str, index);
   }
 
   static void SetCharAt(const String& str, intptr_t index, uint16_t ch) {
     *CharAddr(str, index) = ch;
   }
 
   static RawTwoByteString* EscapeSpecialCharacters(const String& str);
 
   // We use the same maximum elements for all strings.
@@ skipping 79 matching lines @@
                                     Snapshot::Kind kind);
 
   friend class Class;
   friend class String;
   friend class SnapshotReader;
 };
 
 
 class ExternalOneByteString : public AllStatic {
  public:
-  static int32_t CharAt(const String& str, intptr_t index) {
+  static uint16_t CharAt(const String& str, intptr_t index) {
     return *CharAddr(str, index);
   }
 
   static void* GetPeer(const String& str) {
     return raw_ptr(str)->external_data_->peer();
   }
 
   // We use the same maximum elements for all strings.
   static const intptr_t kBytesPerElement = 1;
   static const intptr_t kMaxElements = String::kMaxElements;
@@ skipping 56 matching lines @@
   }
 
   friend class Class;
   friend class String;
   friend class SnapshotReader;
 };
 
 
 class ExternalTwoByteString : public AllStatic {
  public:
-  static int32_t CharAt(const String& str, intptr_t index) {
+  static uint16_t CharAt(const String& str, intptr_t index) {
     return *CharAddr(str, index);
   }
 
   static void* GetPeer(const String& str) {
     return raw_ptr(str)->external_data_->peer();
   }
 
   // We use the same maximum elements for all strings.
   static const intptr_t kBytesPerElement = 2;
   static const intptr_t kMaxElements = String::kMaxElements;
@@ skipping 1377 matching lines @@
 
 
 RawObject* MegamorphicCache::GetTargetFunction(const Array& array,
                                                intptr_t index) {
   return array.At((index * kEntryLength) + kTargetFunctionIndex);
 }
 
 }  // namespace dart
 
 #endif  // VM_OBJECT_H_