/*
- * Copyright (C) 2007, 2008, 2012-2014 Apple Inc. All rights reserved.
+ * Copyright (C) 2007, 2008, 2012-2015 Apple Inc. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
#define SymbolTable_h
#include "ConcurrentJITLock.h"
+#include "ConstantMode.h"
+#include "InferredValue.h"
#include "JSObject.h"
-#include "VariableWatchpointSet.h"
+#include "ScopedArgumentsTable.h"
+#include "TypeLocation.h"
+#include "VarOffset.h"
+#include "Watchpoint.h"
#include <memory>
#include <wtf/HashTraits.h>
-#include <wtf/text/StringImpl.h>
+#include <wtf/text/UniquedStringImpl.h>
namespace JSC {
-struct SlowArgument {
-public:
- enum Status {
- Normal = 0,
- Captured = 1,
- Deleted = 2
- };
-
- SlowArgument()
- : status(Normal)
- , index(0)
- {
- }
-
- Status status;
- int index; // If status is 'Deleted', index is bogus.
-};
+class SymbolTable;
static ALWAYS_INLINE int missingSymbolMarker() { return std::numeric_limits<int>::max(); }
// counted pointer to a shared WatchpointSet. Thus, in-place edits of the
// WatchpointSet will manifest in all copies. Here's a picture:
//
-// SymbolTableEntry --> FatEntry --> VariableWatchpointSet
+// SymbolTableEntry --> FatEntry --> WatchpointSet
//
// If you make a copy of a SymbolTableEntry, you will have:
//
-// original: SymbolTableEntry --> FatEntry --> VariableWatchpointSet
+// original: SymbolTableEntry --> FatEntry --> WatchpointSet
// copy: SymbolTableEntry --> FatEntry -----^
struct SymbolTableEntry {
+private:
+ static VarOffset varOffsetFromBits(intptr_t bits)
+ {
+ VarKind kind;
+ intptr_t kindBits = bits & KindBitsMask;
+ if (kindBits <= UnwatchableScopeKindBits)
+ kind = VarKind::Scope;
+ else if (kindBits == StackKindBits)
+ kind = VarKind::Stack;
+ else
+ kind = VarKind::DirectArgument;
+ return VarOffset::assemble(kind, static_cast<int>(bits >> FlagBits));
+ }
+
+ static ScopeOffset scopeOffsetFromBits(intptr_t bits)
+ {
+ ASSERT((bits & KindBitsMask) <= UnwatchableScopeKindBits);
+ return ScopeOffset(static_cast<int>(bits >> FlagBits));
+ }
+
+public:
+
// Use the SymbolTableEntry::Fast class, either via implicit cast or by calling
// getFast(), when you (1) only care about isNull(), getIndex(), and isReadOnly(),
// and (2) you are in a hot path where you need to minimize the number of times
return !(m_bits & ~SlimFlag);
}
- int getIndex() const
+ VarOffset varOffset() const
{
- return static_cast<int>(m_bits >> FlagBits);
+ return varOffsetFromBits(m_bits);
}
-
+
+ // Asserts if the offset is anything but a scope offset. This structures the assertions
+ // in a way that may result in better code, even in release, than doing
+ // varOffset().scopeOffset().
+ ScopeOffset scopeOffset() const
+ {
+ return scopeOffsetFromBits(m_bits);
+ }
+
bool isReadOnly() const
{
return m_bits & ReadOnlyFlag;
}
+ bool isDontEnum() const
+ {
+ return m_bits & DontEnumFlag;
+ }
+
unsigned getAttributes() const
{
unsigned attributes = 0;
- if (m_bits & ReadOnlyFlag)
+ if (isReadOnly())
attributes |= ReadOnly;
- if (m_bits & DontEnumFlag)
+ if (isDontEnum())
attributes |= DontEnum;
return attributes;
}
{
}
- SymbolTableEntry(int index)
+ SymbolTableEntry(VarOffset offset)
: m_bits(SlimFlag)
{
- ASSERT(isValidIndex(index));
- pack(index, false, false);
+ ASSERT(isValidVarOffset(offset));
+ pack(offset, true, false, false);
}
- SymbolTableEntry(int index, unsigned attributes)
+ SymbolTableEntry(VarOffset offset, unsigned attributes)
: m_bits(SlimFlag)
{
- ASSERT(isValidIndex(index));
- pack(index, attributes & ReadOnly, attributes & DontEnum);
+ ASSERT(isValidVarOffset(offset));
+ pack(offset, true, attributes & ReadOnly, attributes & DontEnum);
}
~SymbolTableEntry()
return !(bits() & ~SlimFlag);
}
- int getIndex() const
+ VarOffset varOffset() const
{
- return static_cast<int>(bits() >> FlagBits);
+ return varOffsetFromBits(bits());
+ }
+
+ bool isWatchable() const
+ {
+ return (m_bits & KindBitsMask) == ScopeKindBits;
+ }
+
+ // Asserts if the offset is anything but a scope offset. This structures the assertions
+ // in a way that may result in better code, even in release, than doing
+ // varOffset().scopeOffset().
+ ScopeOffset scopeOffset() const
+ {
+ return scopeOffsetFromBits(bits());
}
ALWAYS_INLINE Fast getFast() const
{
return getFast().getAttributes();
}
-
+
void setAttributes(unsigned attributes)
{
- pack(getIndex(), attributes & ReadOnly, attributes & DontEnum);
+ pack(varOffset(), isWatchable(), attributes & ReadOnly, attributes & DontEnum);
}
bool isReadOnly() const
return bits() & ReadOnlyFlag;
}
- JSValue inferredValue();
+ ConstantMode constantMode() const
+ {
+ return modeForIsConstant(isReadOnly());
+ }
+
+ bool isDontEnum() const
+ {
+ return bits() & DontEnumFlag;
+ }
+
+ void disableWatching()
+ {
+ if (WatchpointSet* set = watchpointSet())
+ set->invalidate("Disabling watching in symbol table");
+ if (varOffset().isScope())
+ pack(varOffset(), false, isReadOnly(), isDontEnum());
+ }
- void prepareToWatch(SymbolTable*);
+ void prepareToWatch();
void addWatchpoint(Watchpoint*);
- VariableWatchpointSet* watchpointSet()
+ // This watchpoint set is initialized clear, and goes through the following state transitions:
+ //
+ // First write to this var, in any scope that has this symbol table: Clear->IsWatched.
+ //
+ // Second write to this var, in any scope that has this symbol table: IsWatched->IsInvalidated.
+ //
+ // We ensure that we touch the set (i.e. trigger its state transition) after we do the write. This
+ // means that if you're in the compiler thread, and you:
+ //
+ // 1) Observe that the set IsWatched and commit to adding your watchpoint.
+ // 2) Load a value from any scope that has this watchpoint set.
+ //
+ // Then you can be sure that that value is either going to be the correct value for that var forever,
+ // or the watchpoint set will invalidate and you'll get fired.
+ //
+ // It's possible to write a program that first creates multiple scopes with the same var, and then
+ // initializes that var in just one of them. This means that a compilation could constant-fold to one
+ // of the scopes that still has an undefined value for this variable. That's fine, because at that
+ // point any write to any of the instances of that variable would fire the watchpoint.
+ WatchpointSet* watchpointSet()
{
if (!isFat())
return 0;
return fatEntry()->m_watchpoints.get();
}
- ALWAYS_INLINE void notifyWrite(VM& vm, JSValue value)
- {
- if (LIKELY(!isFat()))
- return;
- notifyWriteSlow(vm, value);
- }
-
private:
static const intptr_t SlimFlag = 0x1;
static const intptr_t ReadOnlyFlag = 0x2;
static const intptr_t DontEnumFlag = 0x4;
static const intptr_t NotNullFlag = 0x8;
- static const intptr_t FlagBits = 4;
+ static const intptr_t KindBitsMask = 0x30;
+ static const intptr_t ScopeKindBits = 0x00;
+ static const intptr_t UnwatchableScopeKindBits = 0x10;
+ static const intptr_t StackKindBits = 0x20;
+ static const intptr_t DirectArgumentKindBits = 0x30;
+ static const intptr_t FlagBits = 6;
class FatEntry {
WTF_MAKE_FAST_ALLOCATED;
intptr_t m_bits; // always has FatFlag set and exactly matches what the bits would have been if this wasn't fat.
- RefPtr<VariableWatchpointSet> m_watchpoints;
+ RefPtr<WatchpointSet> m_watchpoints;
};
SymbolTableEntry& copySlow(const SymbolTableEntry&);
- JS_EXPORT_PRIVATE void notifyWriteSlow(VM&, JSValue);
+ JS_EXPORT_PRIVATE void notifyWriteSlow(VM&, JSValue, const FireDetail&);
bool isFat() const
{
JS_EXPORT_PRIVATE void freeFatEntrySlow();
- void pack(int index, bool readOnly, bool dontEnum)
+ void pack(VarOffset offset, bool isWatchable, bool readOnly, bool dontEnum)
{
ASSERT(!isFat());
intptr_t& bitsRef = bits();
- bitsRef = (static_cast<intptr_t>(index) << FlagBits) | NotNullFlag | SlimFlag;
+ bitsRef =
+ (static_cast<intptr_t>(offset.rawOffset()) << FlagBits) | NotNullFlag | SlimFlag;
if (readOnly)
bitsRef |= ReadOnlyFlag;
if (dontEnum)
bitsRef |= DontEnumFlag;
+ switch (offset.kind()) {
+ case VarKind::Scope:
+ if (isWatchable)
+ bitsRef |= ScopeKindBits;
+ else
+ bitsRef |= UnwatchableScopeKindBits;
+ break;
+ case VarKind::Stack:
+ bitsRef |= StackKindBits;
+ break;
+ case VarKind::DirectArgument:
+ bitsRef |= DirectArgumentKindBits;
+ break;
+ default:
+ RELEASE_ASSERT_NOT_REACHED();
+ break;
+ }
}
- bool isValidIndex(int index)
+ static bool isValidVarOffset(VarOffset offset)
{
- return ((static_cast<intptr_t>(index) << FlagBits) >> FlagBits) == static_cast<intptr_t>(index);
+ return ((static_cast<intptr_t>(offset.rawOffset()) << FlagBits) >> FlagBits) == static_cast<intptr_t>(offset.rawOffset());
}
intptr_t m_bits;
static const bool needsDestruction = true;
};
-class SymbolTable : public JSCell {
+class SymbolTable final : public JSCell {
public:
typedef JSCell Base;
+ static const unsigned StructureFlags = Base::StructureFlags | StructureIsImmortal;
- typedef HashMap<RefPtr<StringImpl>, SymbolTableEntry, IdentifierRepHash, HashTraits<RefPtr<StringImpl>>, SymbolTableIndexHashTraits> Map;
+ typedef HashMap<RefPtr<UniquedStringImpl>, SymbolTableEntry, IdentifierRepHash, HashTraits<RefPtr<UniquedStringImpl>>, SymbolTableIndexHashTraits> Map;
+ typedef HashMap<RefPtr<UniquedStringImpl>, GlobalVariableID, IdentifierRepHash> UniqueIDMap;
+ typedef HashMap<RefPtr<UniquedStringImpl>, RefPtr<TypeSet>, IdentifierRepHash> UniqueTypeSetMap;
+ typedef HashMap<VarOffset, RefPtr<UniquedStringImpl>> OffsetToVariableMap;
+ typedef Vector<SymbolTableEntry*> LocalToEntryVec;
static SymbolTable* create(VM& vm)
{
symbolTable->finishCreation(vm);
return symbolTable;
}
+
+ static SymbolTable* createNameScopeTable(VM& vm, const Identifier& ident, unsigned attributes)
+ {
+ SymbolTable* result = create(vm);
+ result->add(ident.impl(), SymbolTableEntry(VarOffset(ScopeOffset(0)), attributes));
+ return result;
+ }
+
static const bool needsDestruction = true;
- static const bool hasImmortalStructure = true;
static void destroy(JSCell*);
static Structure* createStructure(VM& vm, JSGlobalObject* globalObject, JSValue prototype)
{
- return Structure::create(vm, globalObject, prototype, TypeInfo(LeafType, StructureFlags), info());
+ return Structure::create(vm, globalObject, prototype, TypeInfo(CellType, StructureFlags), info());
}
// You must hold the lock until after you're done with the iterator.
- Map::iterator find(const ConcurrentJITLocker&, StringImpl* key)
+ Map::iterator find(const ConcurrentJITLocker&, UniquedStringImpl* key)
{
return m_map.find(key);
}
- Map::iterator find(const GCSafeConcurrentJITLocker&, StringImpl* key)
+ Map::iterator find(const GCSafeConcurrentJITLocker&, UniquedStringImpl* key)
{
return m_map.find(key);
}
- SymbolTableEntry get(const ConcurrentJITLocker&, StringImpl* key)
+ SymbolTableEntry get(const ConcurrentJITLocker&, UniquedStringImpl* key)
{
return m_map.get(key);
}
- SymbolTableEntry get(StringImpl* key)
+ SymbolTableEntry get(UniquedStringImpl* key)
{
ConcurrentJITLocker locker(m_lock);
return get(locker, key);
}
- SymbolTableEntry inlineGet(const ConcurrentJITLocker&, StringImpl* key)
+ SymbolTableEntry inlineGet(const ConcurrentJITLocker&, UniquedStringImpl* key)
{
return m_map.inlineGet(key);
}
- SymbolTableEntry inlineGet(StringImpl* key)
+ SymbolTableEntry inlineGet(UniquedStringImpl* key)
{
ConcurrentJITLocker locker(m_lock);
return inlineGet(locker, key);
return size(locker);
}
- Map::AddResult add(const ConcurrentJITLocker&, StringImpl* key, const SymbolTableEntry& entry)
+ ScopeOffset maxScopeOffset() const
+ {
+ return m_maxScopeOffset;
+ }
+
+ void didUseScopeOffset(ScopeOffset offset)
+ {
+ if (!m_maxScopeOffset || m_maxScopeOffset < offset)
+ m_maxScopeOffset = offset;
+ }
+
+ void didUseVarOffset(VarOffset offset)
{
- return m_map.add(key, entry);
+ if (offset.isScope())
+ didUseScopeOffset(offset.scopeOffset());
}
- void add(StringImpl* key, const SymbolTableEntry& entry)
+ unsigned scopeSize() const
+ {
+ ScopeOffset maxScopeOffset = this->maxScopeOffset();
+
+ // Do some calculation that relies on invalid scope offset plus one being zero.
+ unsigned fastResult = maxScopeOffset.offsetUnchecked() + 1;
+
+ // Assert that this works.
+ ASSERT(fastResult == (!maxScopeOffset ? 0 : maxScopeOffset.offset() + 1));
+
+ return fastResult;
+ }
+
+ ScopeOffset nextScopeOffset() const
+ {
+ return ScopeOffset(scopeSize());
+ }
+
+ ScopeOffset takeNextScopeOffset(const ConcurrentJITLocker&)
+ {
+ ScopeOffset result = nextScopeOffset();
+ m_maxScopeOffset = result;
+ return result;
+ }
+
+ ScopeOffset takeNextScopeOffset()
+ {
+ ConcurrentJITLocker locker(m_lock);
+ return takeNextScopeOffset(locker);
+ }
+
+ void add(const ConcurrentJITLocker&, UniquedStringImpl* key, const SymbolTableEntry& entry)
+ {
+ RELEASE_ASSERT(!m_localToEntry);
+ didUseVarOffset(entry.varOffset());
+ Map::AddResult result = m_map.add(key, entry);
+ ASSERT_UNUSED(result, result.isNewEntry);
+ }
+
+ void add(UniquedStringImpl* key, const SymbolTableEntry& entry)
{
ConcurrentJITLocker locker(m_lock);
add(locker, key, entry);
}
- Map::AddResult set(const ConcurrentJITLocker&, StringImpl* key, const SymbolTableEntry& entry)
+ void set(const ConcurrentJITLocker&, UniquedStringImpl* key, const SymbolTableEntry& entry)
{
- return m_map.set(key, entry);
+ RELEASE_ASSERT(!m_localToEntry);
+ didUseVarOffset(entry.varOffset());
+ m_map.set(key, entry);
}
- void set(StringImpl* key, const SymbolTableEntry& entry)
+ void set(UniquedStringImpl* key, const SymbolTableEntry& entry)
{
ConcurrentJITLocker locker(m_lock);
set(locker, key, entry);
}
- bool contains(const ConcurrentJITLocker&, StringImpl* key)
+ bool contains(const ConcurrentJITLocker&, UniquedStringImpl* key)
{
return m_map.contains(key);
}
- bool contains(StringImpl* key)
+ bool contains(UniquedStringImpl* key)
{
ConcurrentJITLocker locker(m_lock);
return contains(locker, key);
}
- bool usesNonStrictEval() { return m_usesNonStrictEval; }
- void setUsesNonStrictEval(bool usesNonStrictEval) { m_usesNonStrictEval = usesNonStrictEval; }
-
- int captureStart() const { return m_captureStart; }
- void setCaptureStart(int captureStart) { m_captureStart = captureStart; }
-
- int captureEnd() const { return m_captureEnd; }
- void setCaptureEnd(int captureEnd) { m_captureEnd = captureEnd; }
-
- int captureCount() const { return -(m_captureEnd - m_captureStart); }
+ // The principle behind ScopedArgumentsTable modifications is that we will create one and
+ // leave it unlocked - thereby allowing in-place changes - until someone asks for a pointer to
+ // the table. Then, we will lock it. Then both our future changes and their future changes
+ // will first have to make a copy. This discipline means that usually when we create a
+ // ScopedArguments object, we don't have to make a copy of the ScopedArgumentsTable - instead
+ // we just take a reference to one that we already have.
+
+ uint32_t argumentsLength() const
+ {
+ if (!m_arguments)
+ return 0;
+ return m_arguments->length();
+ }
- bool isCaptured(int operand)
+ void setArgumentsLength(VM& vm, uint32_t length)
{
- return operand <= captureStart() && operand > captureEnd();
+ if (UNLIKELY(!m_arguments))
+ m_arguments.set(vm, this, ScopedArgumentsTable::create(vm));
+ m_arguments.set(vm, this, m_arguments->setLength(vm, length));
}
+
+ ScopeOffset argumentOffset(uint32_t i) const
+ {
+ ASSERT_WITH_SECURITY_IMPLICATION(m_arguments);
+ return m_arguments->get(i);
+ }
+
+ void setArgumentOffset(VM& vm, uint32_t i, ScopeOffset offset)
+ {
+ ASSERT_WITH_SECURITY_IMPLICATION(m_arguments);
+ m_arguments.set(vm, this, m_arguments->set(vm, i, offset));
+ }
+
+ ScopedArgumentsTable* arguments() const
+ {
+ if (!m_arguments)
+ return nullptr;
+ m_arguments->lock();
+ return m_arguments.get();
+ }
+
+ const LocalToEntryVec& localToEntry(const ConcurrentJITLocker&);
+ SymbolTableEntry* entryFor(const ConcurrentJITLocker&, ScopeOffset);
+
+ GlobalVariableID uniqueIDForVariable(const ConcurrentJITLocker&, UniquedStringImpl* key, VM&);
+ GlobalVariableID uniqueIDForOffset(const ConcurrentJITLocker&, VarOffset, VM&);
+ RefPtr<TypeSet> globalTypeSetForOffset(const ConcurrentJITLocker&, VarOffset, VM&);
+ RefPtr<TypeSet> globalTypeSetForVariable(const ConcurrentJITLocker&, UniquedStringImpl* key, VM&);
+
+ bool usesNonStrictEval() { return m_usesNonStrictEval; }
+ void setUsesNonStrictEval(bool usesNonStrictEval) { m_usesNonStrictEval = usesNonStrictEval; }
- int parameterCount() { return m_parameterCountIncludingThis - 1; }
- int parameterCountIncludingThis() { return m_parameterCountIncludingThis; }
- void setParameterCountIncludingThis(int parameterCountIncludingThis) { m_parameterCountIncludingThis = parameterCountIncludingThis; }
+ SymbolTable* cloneScopePart(VM&);
- // 0 if we don't capture any arguments; parameterCount() in length if we do.
- const SlowArgument* slowArguments() { return m_slowArguments.get(); }
- void setSlowArguments(std::unique_ptr<SlowArgument[]> slowArguments) { m_slowArguments = WTF::move(slowArguments); }
+ void prepareForTypeProfiling(const ConcurrentJITLocker&);
- SymbolTable* cloneCapturedNames(VM&);
+ InferredValue* singletonScope() { return m_singletonScope.get(); }
static void visitChildren(JSCell*, SlotVisitor&);
DECLARE_EXPORT_INFO;
-protected:
- static const unsigned StructureFlags = StructureIsImmortal | Base::StructureFlags;
-
private:
- class WatchpointCleanup : public UnconditionalFinalizer {
- public:
- WatchpointCleanup(SymbolTable*);
- virtual ~WatchpointCleanup();
-
- protected:
- virtual void finalizeUnconditionally() override;
-
- private:
- SymbolTable* m_symbolTable;
- };
-
JS_EXPORT_PRIVATE SymbolTable(VM&);
~SymbolTable();
+
+ JS_EXPORT_PRIVATE void finishCreation(VM&);
Map m_map;
+ ScopeOffset m_maxScopeOffset;
- int m_parameterCountIncludingThis;
- bool m_usesNonStrictEval;
-
- int m_captureStart;
- int m_captureEnd;
+ struct TypeProfilingRareData {
+ UniqueIDMap m_uniqueIDMap;
+ OffsetToVariableMap m_offsetToVariableMap;
+ UniqueTypeSetMap m_uniqueTypeSetMap;
+ };
+ std::unique_ptr<TypeProfilingRareData> m_typeProfilingRareData;
- std::unique_ptr<SlowArgument[]> m_slowArguments;
+ bool m_usesNonStrictEval;
+
+ WriteBarrier<ScopedArgumentsTable> m_arguments;
+ WriteBarrier<InferredValue> m_singletonScope;
- std::unique_ptr<WatchpointCleanup> m_watchpointCleanup;
+ std::unique_ptr<LocalToEntryVec> m_localToEntry;
public:
- InlineWatchpointSet m_functionEnteredOnce;
-
mutable ConcurrentJITLock m_lock;
};
projects / apple / javascriptcore.git / blobdiff