Changeset 24059 in webkit for trunk/JavaScriptCore/wtf/HashMap.h

Timestamp:

Jul 6, 2007, 5:09:08 AM (18 years ago)

Author:

mjs

Message:

JavaScriptCore:

Reviewed by Antti.

• <rdar://problem/5311093> JavaScriptCore fails to build with strict-aliasing warnings

• Configurations/Base.xcconfig: Re-enable -Wstrict-aliasing
• bindings/jni/jni_utility.cpp: (KJS::Bindings::getJNIEnv): Type-pun via a union instead of a pointer cast.
• wtf/HashMap.h: (WTF::): Instead of doing type-punned assignments via pointer cast, do one of three things: (1) assign directly w/o cast if storage type matches real type; (2) assign using cast via union if type does not need reffing; (3) copy with memcpy and ref/deref manually if type needs reffing. This is ok peref-wise because memcpy of a constant length gets optomized. HashTraits are now expected to make ref()/deref() take the storage type, not the true type.
• wtf/HashSet.h: (WTF::): Same basic idea.
• wtf/HashTable.h: (WTF::): Added Assigner template for use by HashMap/HashSet. Change RefCounter to call ref() and deref() via storage type, avoiding the need to type-pun. (WTF::RefCounter::ref): ditto (WTF::RefCounter::deref): ditto
• wtf/HashTraits.h: (WTF::): Change ref() and deref() for RefPtr HashTraits to take the storage type; cast via union to pointer type.
• wtf/FastMalloc.cpp: (WTF::TCMalloc_PageHeap::init): Changed from constructor to init function so this can go in a union. (WTF::): redefine pageheap macro in terms of getPageHeap(). (WTF::getPageHeap): new inline function, helper for pageheap macro. This hides the cast in a union. (WTF::TCMalloc_ThreadCache::InitModule): Call init() instead of using placement new to initialize page heap.
• wtf/TCPageMap.h: (TCMalloc_PageMap1::init): Changed from constructor to init function. (TCMalloc_PageMap2::init): ditto (TCMalloc_PageMap3::init): ditto

WebCore:

Reviewed by Antti.

• <rdar://problem/5311093> JavaScriptCore fails to build with strict-aliasing warnings

• platform/StringHash.h: (WTF::): Adapt to newer way to do storage types.

File:

• trunk/JavaScriptCore/wtf/HashMap.h (modified) (6 diffs)

trunk/JavaScriptCore/wtf/HashMap.h

@@ -112 +112 @@
     };
 
-    template<bool canReplaceDeletedKey, typename ValueType, typename ValueStorageTraits, typename HashFunctions>
+    template<bool canReplaceDeletedKey, typename ValueType, typename ValueTraits, typename ValueStorageTraits, typename HashFunctions>
     struct HashMapTranslator;
 
-    template<typename ValueType, typename ValueStorageTraits, typename HashFunctions>
-    struct HashMapTranslator<true, ValueType, ValueStorageTraits, HashFunctions> {
+    template<typename ValueType, typename ValueTraits, typename ValueStorageTraits, typename HashFunctions>
+    struct HashMapTranslator<true, ValueType, ValueTraits, ValueStorageTraits, HashFunctions> {
         typedef typename ValueType::first_type KeyType;
         typedef typename ValueType::second_type MappedType;
@@ -122 +122 @@
         typedef typename ValueStorageTraits::FirstTraits KeyStorageTraits;
         typedef typename KeyStorageTraits::TraitType KeyStorageType;
+        typedef typename ValueStorageTraits::SecondTraits MappedStorageTraits;
+        typedef typename MappedStorageTraits::TraitType MappedStorageType;
+        typedef typename ValueTraits::FirstTraits KeyTraits;
+        typedef typename ValueTraits::SecondTraits MappedTraits;
 
         static unsigned hash(const KeyType& key) { return HashFunctions::hash(key); }
@@ -127 +131 @@
         static void translate(ValueStorageType& location, const KeyType& key, const MappedType& mapped, unsigned)
         {
-            *(KeyType*)&location.first = key;
-            *(MappedType*)&location.second = mapped;
+            Assigner<KeyTraits::needsRef, KeyType, KeyStorageType, KeyTraits>::assign(key, location.first);
+            Assigner<MappedTraits::needsRef, MappedType, MappedStorageType, MappedTraits>::assign(mapped, location.second);
         }
     };
 
-    template<typename ValueType, typename ValueStorageTraits, typename HashFunctions>
-    struct HashMapTranslator<false, ValueType, ValueStorageTraits, HashFunctions> {
+    template<typename ValueType, typename ValueTraits, typename ValueStorageTraits, typename HashFunctions>
+    struct HashMapTranslator<false, ValueType, ValueTraits, ValueStorageTraits, HashFunctions> {
         typedef typename ValueType::first_type KeyType;
         typedef typename ValueType::second_type MappedType;
@@ -139 +143 @@
         typedef typename ValueStorageTraits::FirstTraits KeyStorageTraits;
         typedef typename KeyStorageTraits::TraitType KeyStorageType;
-
+        typedef typename ValueStorageTraits::SecondTraits MappedStorageTraits;
+        typedef typename MappedStorageTraits::TraitType MappedStorageType;
+        typedef typename ValueTraits::FirstTraits KeyTraits;
+        typedef typename ValueTraits::SecondTraits MappedTraits;
+        
         static unsigned hash(const KeyType& key) { return HashFunctions::hash(key); }
         static bool equal(const KeyStorageType& a, const KeyType& b) { return HashFunctions::equal(*(KeyType*)&a, b); }
@@ -146 +154 @@
             if (location.first == KeyStorageTraits::deletedValue())
                 location.first = KeyStorageTraits::emptyValue();
-            *(KeyType*)&location.first = key;
-            *(MappedType*)&location.second = mapped;
+            Assigner<KeyTraits::needsRef, KeyType, KeyStorageType, KeyTraits>::assign(key, location.first);
+            Assigner<MappedTraits::needsRef, MappedType, MappedStorageType, MappedTraits>::assign(mapped, location.second);
         }
     };
@@ -260 +268 @@
     {
         const bool canReplaceDeletedKey = !KeyTraits::needsDestruction || KeyStorageTraits::needsDestruction;
-        typedef HashMapTranslator<canReplaceDeletedKey, ValueType, ValueStorageTraits, HashFunctions> TranslatorType;
+        typedef HashMapTranslator<canReplaceDeletedKey, ValueType, ValueTraits, ValueStorageTraits, HashFunctions> TranslatorType;
         return m_impl.template add<KeyType, MappedType, TranslatorType>(key, mapped);
     }