1 files changed, 261 insertions, 0 deletions
diff --git a/Source/JavaScriptCore/runtime/SymbolTable.cpp b/Source/JavaScriptCore/runtime/SymbolTable.cpp
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+++ b/Source/JavaScriptCore/runtime/SymbolTable.cpp
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+/*
+ * Copyright (C) 2012, 2014, 2015 Apple Inc. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1.  Redistributions of source code must retain the above copyright
+ *     notice, this list of conditions and the following disclaimer.
+ * 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
+ *     its contributors may be used to endorse or promote products derived
+ *     from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY
+ * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY
+ * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "config.h"
+#include "SymbolTable.h"
+
+#include "JSDestructibleObject.h"
+#include "JSCInlines.h"
+#include "SlotVisitorInlines.h"
+#include "TypeProfiler.h"
+
+namespace JSC {
+
+const ClassInfo SymbolTable::s_info = { "SymbolTable", 0, 0, CREATE_METHOD_TABLE(SymbolTable) };
+
+SymbolTableEntry& SymbolTableEntry::copySlow(const SymbolTableEntry& other)
+{
+    ASSERT(other.isFat());
+    FatEntry* newFatEntry = new FatEntry(*other.fatEntry());
+    freeFatEntry();
+    m_bits = bitwise_cast<intptr_t>(newFatEntry);
+    return *this;
+}
+
+void SymbolTable::destroy(JSCell* cell)
+{
+    SymbolTable* thisObject = jsCast<SymbolTable*>(cell);
+    thisObject->SymbolTable::~SymbolTable();
+}
+
+void SymbolTableEntry::freeFatEntrySlow()
+{
+    ASSERT(isFat());
+    delete fatEntry();
+}
+
+void SymbolTableEntry::prepareToWatch()
+{
+    if (!isWatchable())
+        return;
+    FatEntry* entry = inflate();
+    if (entry->m_watchpoints)
+        return;
+    entry->m_watchpoints = adoptRef(new WatchpointSet(ClearWatchpoint));
+}
+
+void SymbolTableEntry::addWatchpoint(Watchpoint* watchpoint)
+{
+    fatEntry()->m_watchpoints->add(watchpoint);
+}
+
+SymbolTableEntry::FatEntry* SymbolTableEntry::inflateSlow()
+{
+    FatEntry* entry = new FatEntry(m_bits);
+    m_bits = bitwise_cast<intptr_t>(entry);
+    return entry;
+}
+
+SymbolTable::SymbolTable(VM& vm)
+    : JSCell(vm, vm.symbolTableStructure.get())
+    , m_usesNonStrictEval(false)
+    , m_scopeType(VarScope)
+{
+}
+
+SymbolTable::~SymbolTable() { }
+
+void SymbolTable::finishCreation(VM& vm)
+{
+    Base::finishCreation(vm);
+    m_singletonScope.set(vm, this, InferredValue::create(vm));
+}
+
+void SymbolTable::visitChildren(JSCell* thisCell, SlotVisitor& visitor)
+{
+    SymbolTable* thisSymbolTable = jsCast<SymbolTable*>(thisCell);
+    
+    visitor.append(&thisSymbolTable->m_arguments);
+    visitor.append(&thisSymbolTable->m_singletonScope);
+    
+    // Save some memory. This is O(n) to rebuild and we do so on the fly.
+    ConcurrentJITLocker locker(thisSymbolTable->m_lock);
+    thisSymbolTable->m_localToEntry = nullptr;
+}
+
+const SymbolTable::LocalToEntryVec& SymbolTable::localToEntry(const ConcurrentJITLocker&)
+{
+    if (UNLIKELY(!m_localToEntry)) {
+        unsigned size = 0;
+        for (auto& entry : m_map) {
+            VarOffset offset = entry.value.varOffset();
+            if (offset.isScope())
+                size = std::max(size, offset.scopeOffset().offset() + 1);
+        }
+    
+        m_localToEntry = std::make_unique<LocalToEntryVec>(size, nullptr);
+        for (auto& entry : m_map) {
+            VarOffset offset = entry.value.varOffset();
+            if (offset.isScope())
+                m_localToEntry->at(offset.scopeOffset().offset()) = &entry.value;
+        }
+    }
+    
+    return *m_localToEntry;
+}
+
+SymbolTableEntry* SymbolTable::entryFor(const ConcurrentJITLocker& locker, ScopeOffset offset)
+{
+    auto& toEntryVector = localToEntry(locker);
+    if (offset.offset() >= toEntryVector.size())
+        return nullptr;
+    return toEntryVector[offset.offset()];
+}
+
+SymbolTable* SymbolTable::cloneScopePart(VM& vm)
+{
+    SymbolTable* result = SymbolTable::create(vm);
+    
+    result->m_usesNonStrictEval = m_usesNonStrictEval;
+    result->m_scopeType = m_scopeType;
+
+    for (auto iter = m_map.begin(), end = m_map.end(); iter != end; ++iter) {
+        if (!iter->value.varOffset().isScope())
+            continue;
+        result->m_map.add(
+            iter->key,
+            SymbolTableEntry(iter->value.varOffset(), iter->value.getAttributes()));
+    }
+    
+    result->m_maxScopeOffset = m_maxScopeOffset;
+    
+    if (ScopedArgumentsTable* arguments = this->arguments())
+        result->m_arguments.set(vm, result, arguments);
+    
+    if (m_typeProfilingRareData) {
+        result->m_typeProfilingRareData = std::make_unique<TypeProfilingRareData>();
+
+        {
+            auto iter = m_typeProfilingRareData->m_uniqueIDMap.begin();
+            auto end = m_typeProfilingRareData->m_uniqueIDMap.end();
+            for (; iter != end; ++iter)
+                result->m_typeProfilingRareData->m_uniqueIDMap.set(iter->key, iter->value);
+        }
+
+        {
+            auto iter = m_typeProfilingRareData->m_offsetToVariableMap.begin();
+            auto end = m_typeProfilingRareData->m_offsetToVariableMap.end();
+            for (; iter != end; ++iter)
+                result->m_typeProfilingRareData->m_offsetToVariableMap.set(iter->key, iter->value);
+        }
+
+        {
+            auto iter = m_typeProfilingRareData->m_uniqueTypeSetMap.begin();
+            auto end = m_typeProfilingRareData->m_uniqueTypeSetMap.end();
+            for (; iter != end; ++iter)
+                result->m_typeProfilingRareData->m_uniqueTypeSetMap.set(iter->key, iter->value);
+        }
+    }
+    
+    return result;
+}
+
+void SymbolTable::prepareForTypeProfiling(const ConcurrentJITLocker&)
+{
+    if (m_typeProfilingRareData)
+        return;
+
+    m_typeProfilingRareData = std::make_unique<TypeProfilingRareData>();
+
+    for (auto iter = m_map.begin(), end = m_map.end(); iter != end; ++iter) {
+        m_typeProfilingRareData->m_uniqueIDMap.set(iter->key, TypeProfilerNeedsUniqueIDGeneration);
+        m_typeProfilingRareData->m_offsetToVariableMap.set(iter->value.varOffset(), iter->key);
+    }
+}
+
+GlobalVariableID SymbolTable::uniqueIDForVariable(const ConcurrentJITLocker&, UniquedStringImpl* key, VM& vm)
+{
+    RELEASE_ASSERT(m_typeProfilingRareData);
+
+    auto iter = m_typeProfilingRareData->m_uniqueIDMap.find(key);
+    auto end = m_typeProfilingRareData->m_uniqueIDMap.end();
+    if (iter == end)
+        return TypeProfilerNoGlobalIDExists;
+
+    GlobalVariableID id = iter->value;
+    if (id == TypeProfilerNeedsUniqueIDGeneration) {
+        id = vm.typeProfiler()->getNextUniqueVariableID();
+        m_typeProfilingRareData->m_uniqueIDMap.set(key, id);
+        m_typeProfilingRareData->m_uniqueTypeSetMap.set(key, TypeSet::create()); // Make a new global typeset for this corresponding ID.
+    }
+
+    return id;
+}
+
+GlobalVariableID SymbolTable::uniqueIDForOffset(const ConcurrentJITLocker& locker, VarOffset offset, VM& vm)
+{
+    RELEASE_ASSERT(m_typeProfilingRareData);
+
+    auto iter = m_typeProfilingRareData->m_offsetToVariableMap.find(offset);
+    auto end = m_typeProfilingRareData->m_offsetToVariableMap.end();
+    if (iter == end)
+        return TypeProfilerNoGlobalIDExists;
+
+    return uniqueIDForVariable(locker, iter->value.get(), vm);
+}
+
+RefPtr<TypeSet> SymbolTable::globalTypeSetForOffset(const ConcurrentJITLocker& locker, VarOffset offset, VM& vm)
+{
+    RELEASE_ASSERT(m_typeProfilingRareData);
+
+    uniqueIDForOffset(locker, offset, vm); // Lazily create the TypeSet if necessary.
+
+    auto iter = m_typeProfilingRareData->m_offsetToVariableMap.find(offset);
+    auto end = m_typeProfilingRareData->m_offsetToVariableMap.end();
+    if (iter == end)
+        return nullptr;
+
+    return globalTypeSetForVariable(locker, iter->value.get(), vm);
+}
+
+RefPtr<TypeSet> SymbolTable::globalTypeSetForVariable(const ConcurrentJITLocker& locker, UniquedStringImpl* key, VM& vm)
+{
+    RELEASE_ASSERT(m_typeProfilingRareData);
+
+    uniqueIDForVariable(locker, key, vm); // Lazily create the TypeSet if necessary.
+
+    auto iter = m_typeProfilingRareData->m_uniqueTypeSetMap.find(key);
+    auto end = m_typeProfilingRareData->m_uniqueTypeSetMap.end();
+    if (iter == end)
+        return nullptr;
+
+    return iter->value;
+}
+
+} // namespace JSC
+