webkitgtk-2.4.11webkitgtk-2.4.11

1 files changed, 12 insertions, 79 deletions

diff --git a/Source/JavaScriptCore/bytecode/EvalCodeCache.h b/Source/JavaScriptCore/bytecode/EvalCodeCache.h
index e1c7b2b47..ff5911240 100644
--- a/Source/JavaScriptCore/bytecode/EvalCodeCache.h
+++ b/Source/JavaScriptCore/bytecode/EvalCodeCache.h
@@ -10,7 +10,7 @@
  * 2.  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 with the distribution.
- * 3.  Neither the name of Apple Inc. ("Apple") nor the names of
+ * 3.  Neither the name of Apple Computer, Inc. ("Apple") nor the names of
  *     its contributors may be used to endorse or promote products derived
  *     from this software without specific prior written permission.
  *
@@ -31,8 +31,6 @@
 
 #include "Executable.h"
 #include "JSGlobalObject.h"
-#include "JSScope.h"
-#include "Options.h"
 #include "SourceCode.h"
 #include <wtf/HashMap.h>
 #include <wtf/RefPtr.h>
@@ -44,74 +42,21 @@ namespace JSC {
 
     class EvalCodeCache {
     public:
-        class CacheKey {
-        public:
-            CacheKey(const String& source, bool isArrowFunctionContext)
-                : m_source(source.impl())
-                , m_isArrowFunctionContext(isArrowFunctionContext)
-            {
-            }
-
-            CacheKey(WTF::HashTableDeletedValueType)
-                : m_source(WTF::HashTableDeletedValue)
-            {
-            }
-
-            CacheKey() = default;
-
-            unsigned hash() const { return m_source->hash(); }
-
-            bool isEmptyValue() const { return !m_source; }
-
-            bool operator==(const CacheKey& other) const
-            {
-                return m_source == other.m_source && m_isArrowFunctionContext == other.m_isArrowFunctionContext;
-            }
-
-            bool isHashTableDeletedValue() const { return m_source.isHashTableDeletedValue(); }
-
-            struct Hash {
-                static unsigned hash(const CacheKey& key)
-                {
-                    return key.hash();
-                }
-                static bool equal(const CacheKey& lhs, const CacheKey& rhs)
-                {
-                    return StringHash::equal(lhs.m_source, rhs.m_source) && lhs.m_isArrowFunctionContext == rhs.m_isArrowFunctionContext;
-                }
-                static const bool safeToCompareToEmptyOrDeleted = false;
-            };
-
-            typedef SimpleClassHashTraits<CacheKey> HashTraits;
-
-        private:
-            RefPtr<StringImpl> m_source;
-            bool m_isArrowFunctionContext { false };
-        };
-
-        EvalExecutable* tryGet(bool inStrictContext, const String& evalSource, bool isArrowFunctionContext, JSScope* scope)
+        EvalExecutable* tryGet(bool inStrictContext, const String& evalSource, JSScope* scope)
         {
-            if (isCacheable(inStrictContext, evalSource, scope)) {
-                ASSERT(!inStrictContext);
-                return m_cacheMap.fastGet(CacheKey(evalSource, isArrowFunctionContext)).get();
-            }
-            return nullptr;
+            if (!inStrictContext && evalSource.length() < maxCacheableSourceLength && scope->begin()->isVariableObject())
+                return m_cacheMap.get(evalSource.impl()).get();
+            return 0;
         }
         
-        EvalExecutable* getSlow(ExecState* exec, JSCell* owner, bool inStrictContext, ThisTDZMode thisTDZMode, DerivedContextType derivedContextType, bool isArrowFunctionContext, const String& evalSource, JSScope* scope)
+        EvalExecutable* getSlow(ExecState* exec, ScriptExecutable* owner, bool inStrictContext, const String& evalSource, JSScope* scope)
         {
-            VariableEnvironment variablesUnderTDZ;
-            JSScope::collectVariablesUnderTDZ(scope, variablesUnderTDZ);
-            EvalExecutable* evalExecutable = EvalExecutable::create(exec, makeSource(evalSource), inStrictContext, thisTDZMode, derivedContextType, isArrowFunctionContext, &variablesUnderTDZ);
+            EvalExecutable* evalExecutable = EvalExecutable::create(exec, makeSource(evalSource), inStrictContext);
             if (!evalExecutable)
-                return nullptr;
+                return 0;
 
-            if (isCacheable(inStrictContext, evalSource, scope) && m_cacheMap.size() < maxCacheEntries) {
-                ASSERT(!inStrictContext);
-                ASSERT_WITH_MESSAGE(thisTDZMode == ThisTDZMode::CheckIfNeeded, "Always CheckIfNeeded because the caching is enabled only in the sloppy mode.");
-                ASSERT_WITH_MESSAGE(derivedContextType == DerivedContextType::None, "derivedContextType is always None because class methods and class constructors are always evaluated as the strict code.");
-                m_cacheMap.set(CacheKey(evalSource, isArrowFunctionContext), WriteBarrier<EvalExecutable>(exec->vm(), owner, evalExecutable));
-            }
+            if (!inStrictContext && evalSource.length() < maxCacheableSourceLength && scope->begin()->isVariableObject() && m_cacheMap.size() < maxCacheEntries)
+                m_cacheMap.set(evalSource.impl(), WriteBarrier<EvalExecutable>(exec->vm(), owner, evalExecutable));
             
             return evalExecutable;
         }
@@ -126,22 +71,10 @@ namespace JSC {
         }
 
     private:
-        ALWAYS_INLINE bool isCacheableScope(JSScope* scope)
-        {
-            return scope->isGlobalLexicalEnvironment() || scope->isFunctionNameScopeObject() || scope->isVarScope();
-        }
-
-        ALWAYS_INLINE bool isCacheable(bool inStrictContext, const String& evalSource, JSScope* scope)
-        {
-            // If eval() is called and it has access to a lexical scope, we can't soundly cache it.
-            // If the eval() only has access to the "var" scope, then we can cache it.
-            return !inStrictContext 
-                && static_cast<size_t>(evalSource.length()) < Options::maximumEvalCacheableSourceLength()
-                && isCacheableScope(scope);
-        }
+        static const unsigned maxCacheableSourceLength = 256;
         static const int maxCacheEntries = 64;
 
-        typedef HashMap<CacheKey, WriteBarrier<EvalExecutable>, CacheKey::Hash, CacheKey::HashTraits> EvalCacheMap;
+        typedef HashMap<RefPtr<StringImpl>, WriteBarrier<EvalExecutable>> EvalCacheMap;
         EvalCacheMap m_cacheMap;
     };