darling-JavaScriptCore/parser/VariableEnvironment.h

445 lines
16 KiB
C++

/*
* Copyright (C) 2015-2019 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.
*
* THIS SOFTWARE IS PROVIDED BY APPLE INC. ``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 INC. OR
* 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.
*/
#pragma once
#include "Identifier.h"
#include <wtf/HashMap.h>
#include <wtf/HashSet.h>
#include <wtf/IteratorRange.h>
#include <wtf/Variant.h>
namespace JSC {
struct VariableEnvironmentEntry {
public:
ALWAYS_INLINE bool isCaptured() const { return m_bits & IsCaptured; }
ALWAYS_INLINE bool isConst() const { return m_bits & IsConst; }
ALWAYS_INLINE bool isVar() const { return m_bits & IsVar; }
ALWAYS_INLINE bool isLet() const { return m_bits & IsLet; }
ALWAYS_INLINE bool isExported() const { return m_bits & IsExported; }
ALWAYS_INLINE bool isImported() const { return m_bits & IsImported; }
ALWAYS_INLINE bool isImportedNamespace() const { return m_bits & IsImportedNamespace; }
ALWAYS_INLINE bool isFunction() const { return m_bits & IsFunction; }
ALWAYS_INLINE bool isParameter() const { return m_bits & IsParameter; }
ALWAYS_INLINE bool isSloppyModeHoistingCandidate() const { return m_bits & IsSloppyModeHoistingCandidate; }
ALWAYS_INLINE bool isPrivateName() const { return m_bits & IsPrivateName; }
ALWAYS_INLINE void setIsCaptured() { m_bits |= IsCaptured; }
ALWAYS_INLINE void setIsConst() { m_bits |= IsConst; }
ALWAYS_INLINE void setIsVar() { m_bits |= IsVar; }
ALWAYS_INLINE void setIsLet() { m_bits |= IsLet; }
ALWAYS_INLINE void setIsExported() { m_bits |= IsExported; }
ALWAYS_INLINE void setIsImported() { m_bits |= IsImported; }
ALWAYS_INLINE void setIsImportedNamespace() { m_bits |= IsImportedNamespace; }
ALWAYS_INLINE void setIsFunction() { m_bits |= IsFunction; }
ALWAYS_INLINE void setIsParameter() { m_bits |= IsParameter; }
ALWAYS_INLINE void setIsSloppyModeHoistingCandidate() { m_bits |= IsSloppyModeHoistingCandidate; }
ALWAYS_INLINE void setIsPrivateName() { m_bits |= IsPrivateName; }
ALWAYS_INLINE void clearIsVar() { m_bits &= ~IsVar; }
uint16_t bits() const { return m_bits; }
bool operator==(const VariableEnvironmentEntry& other) const
{
return m_bits == other.m_bits;
}
private:
enum Traits : uint16_t {
IsCaptured = 1 << 0,
IsConst = 1 << 1,
IsVar = 1 << 2,
IsLet = 1 << 3,
IsExported = 1 << 4,
IsImported = 1 << 5,
IsImportedNamespace = 1 << 6,
IsFunction = 1 << 7,
IsParameter = 1 << 8,
IsSloppyModeHoistingCandidate = 1 << 9,
IsPrivateName = 1 << 10,
};
uint16_t m_bits { 0 };
};
struct VariableEnvironmentEntryHashTraits : HashTraits<VariableEnvironmentEntry> {
static constexpr bool needsDestruction = false;
};
struct PrivateNameEntry {
public:
PrivateNameEntry(uint16_t traits = 0) { m_bits = traits; }
ALWAYS_INLINE bool isUsed() const { return m_bits & IsUsed; }
ALWAYS_INLINE bool isDeclared() const { return m_bits & IsDeclared; }
ALWAYS_INLINE void setIsUsed() { m_bits |= IsUsed; }
ALWAYS_INLINE void setIsDeclared() { m_bits |= IsDeclared; }
uint16_t bits() const { return m_bits; }
bool operator==(const PrivateNameEntry& other) const
{
return m_bits == other.m_bits;
}
enum Traits : uint16_t {
IsUsed = 1 << 0,
IsDeclared = 1 << 1,
};
private:
uint16_t m_bits { 0 };
};
struct PrivateNameEntryHashTraits : HashTraits<PrivateNameEntry> {
static const bool needsDestruction = false;
};
class VariableEnvironment {
WTF_MAKE_FAST_ALLOCATED;
private:
typedef HashMap<PackedRefPtr<UniquedStringImpl>, VariableEnvironmentEntry, IdentifierRepHash, HashTraits<RefPtr<UniquedStringImpl>>, VariableEnvironmentEntryHashTraits> Map;
typedef HashMap<PackedRefPtr<UniquedStringImpl>, PrivateNameEntry, IdentifierRepHash, HashTraits<RefPtr<UniquedStringImpl>>, PrivateNameEntryHashTraits> PrivateNames;
public:
VariableEnvironment() { }
VariableEnvironment(VariableEnvironment&& other)
: m_map(WTFMove(other.m_map))
, m_isEverythingCaptured(other.m_isEverythingCaptured)
, m_rareData(WTFMove(other.m_rareData))
{
}
VariableEnvironment(const VariableEnvironment& other)
: m_map(other.m_map)
, m_isEverythingCaptured(other.m_isEverythingCaptured)
, m_rareData(other.m_rareData ? WTF::makeUnique<VariableEnvironment::RareData>(*other.m_rareData) : nullptr)
{
}
VariableEnvironment& operator=(const VariableEnvironment& other);
ALWAYS_INLINE Map::iterator begin() { return m_map.begin(); }
ALWAYS_INLINE Map::iterator end() { return m_map.end(); }
ALWAYS_INLINE Map::const_iterator begin() const { return m_map.begin(); }
ALWAYS_INLINE Map::const_iterator end() const { return m_map.end(); }
ALWAYS_INLINE Map::AddResult add(const RefPtr<UniquedStringImpl>& identifier) { return m_map.add(identifier, VariableEnvironmentEntry()); }
ALWAYS_INLINE Map::AddResult add(const Identifier& identifier) { return add(identifier.impl()); }
ALWAYS_INLINE unsigned size() const { return m_map.size() + privateNamesSize(); }
ALWAYS_INLINE unsigned mapSize() const { return m_map.size(); }
ALWAYS_INLINE bool contains(const RefPtr<UniquedStringImpl>& identifier) const { return m_map.contains(identifier); }
ALWAYS_INLINE bool remove(const RefPtr<UniquedStringImpl>& identifier) { return m_map.remove(identifier); }
ALWAYS_INLINE Map::iterator find(const RefPtr<UniquedStringImpl>& identifier) { return m_map.find(identifier); }
ALWAYS_INLINE Map::const_iterator find(const RefPtr<UniquedStringImpl>& identifier) const { return m_map.find(identifier); }
void swap(VariableEnvironment& other);
void markVariableAsCapturedIfDefined(const RefPtr<UniquedStringImpl>& identifier);
void markVariableAsCaptured(const RefPtr<UniquedStringImpl>& identifier);
void markAllVariablesAsCaptured();
bool hasCapturedVariables() const;
bool captures(UniquedStringImpl* identifier) const;
void markVariableAsImported(const RefPtr<UniquedStringImpl>& identifier);
void markVariableAsExported(const RefPtr<UniquedStringImpl>& identifier);
bool isEverythingCaptured() const { return m_isEverythingCaptured; }
bool isEmpty() const { return !m_map.size(); }
using PrivateNamesRange = WTF::IteratorRange<PrivateNames::iterator>;
ALWAYS_INLINE Map::AddResult declarePrivateName(const Identifier& identifier) { return declarePrivateName(identifier.impl()); }
ALWAYS_INLINE void usePrivateName(const Identifier& identifier) { usePrivateName(identifier.impl()); }
Map::AddResult declarePrivateName(const RefPtr<UniquedStringImpl>& identifier)
{
auto& meta = getOrAddPrivateName(identifier.get());
meta.setIsDeclared();
auto entry = VariableEnvironmentEntry();
entry.setIsPrivateName();
entry.setIsConst();
entry.setIsCaptured();
return m_map.add(identifier, entry);
}
void usePrivateName(const RefPtr<UniquedStringImpl>& identifier)
{
auto& meta = getOrAddPrivateName(identifier.get());
meta.setIsUsed();
if (meta.isDeclared())
find(identifier)->value.setIsCaptured();
}
ALWAYS_INLINE PrivateNamesRange privateNames() const
{
// Use of the IteratorRange must be guarded to prevent ASSERT failures in checkValidity().
ASSERT(privateNamesSize() > 0);
return makeIteratorRange(m_rareData->m_privateNames.begin(), m_rareData->m_privateNames.end());
}
ALWAYS_INLINE unsigned privateNamesSize() const
{
if (!m_rareData)
return 0;
return m_rareData->m_privateNames.size();
}
ALWAYS_INLINE bool hasPrivateName(const Identifier& identifier)
{
if (!m_rareData)
return false;
return m_rareData->m_privateNames.contains(identifier.impl());
}
ALWAYS_INLINE void copyPrivateNamesTo(VariableEnvironment& other) const
{
if (!m_rareData)
return;
if (!other.m_rareData)
other.m_rareData = WTF::makeUnique<VariableEnvironment::RareData>();
if (privateNamesSize() > 0) {
for (auto entry : privateNames()) {
if (!(entry.value.isUsed() && entry.value.isDeclared()))
other.m_rareData->m_privateNames.add(entry.key, entry.value);
}
}
}
ALWAYS_INLINE void copyUndeclaredPrivateNamesTo(VariableEnvironment& outer) const {
// Used by the Parser to transfer recorded uses of PrivateNames from an
// inner PrivateNameEnvironment into an outer one, in case a PNE is used
// earlier in the source code than it is defined.
if (privateNamesSize() > 0) {
for (auto entry : privateNames()) {
if (entry.value.isUsed() && !entry.value.isDeclared())
outer.getOrAddPrivateName(entry.key.get()).setIsUsed();
}
}
}
struct RareData {
WTF_MAKE_STRUCT_FAST_ALLOCATED;
RareData() { }
RareData(RareData&& other)
: m_privateNames(WTFMove(other.m_privateNames))
{
}
RareData(const RareData&) = default;
RareData& operator=(const RareData&) = default;
PrivateNames m_privateNames;
};
private:
friend class CachedVariableEnvironment;
Map m_map;
bool m_isEverythingCaptured { false };
PrivateNameEntry& getOrAddPrivateName(UniquedStringImpl* impl)
{
if (!m_rareData)
m_rareData = WTF::makeUnique<VariableEnvironment::RareData>();
return m_rareData->m_privateNames.add(impl, PrivateNameEntry()).iterator->value;
}
std::unique_ptr<VariableEnvironment::RareData> m_rareData;
};
using TDZEnvironment = HashSet<RefPtr<UniquedStringImpl>, IdentifierRepHash>;
class CompactTDZEnvironment {
WTF_MAKE_FAST_ALLOCATED;
WTF_MAKE_NONCOPYABLE(CompactTDZEnvironment);
friend class CachedCompactTDZEnvironment;
using Compact = Vector<PackedRefPtr<UniquedStringImpl>>;
using Inflated = TDZEnvironment;
using Variables = Variant<Compact, Inflated>;
public:
CompactTDZEnvironment(const TDZEnvironment&);
bool operator==(const CompactTDZEnvironment&) const;
unsigned hash() const { return m_hash; }
static void sortCompact(Compact&);
TDZEnvironment& toTDZEnvironment() const
{
if (WTF::holds_alternative<Inflated>(m_variables))
return const_cast<TDZEnvironment&>(WTF::get<Inflated>(m_variables));
return toTDZEnvironmentSlow();
}
private:
CompactTDZEnvironment() = default;
TDZEnvironment& toTDZEnvironmentSlow() const;
mutable Variables m_variables;
unsigned m_hash;
};
struct CompactTDZEnvironmentKey {
CompactTDZEnvironmentKey()
: m_environment(nullptr)
{
ASSERT(isHashTableEmptyValue());
}
CompactTDZEnvironmentKey(CompactTDZEnvironment& environment)
: m_environment(&environment)
{ }
static unsigned hash(const CompactTDZEnvironmentKey& key) { return key.m_environment->hash(); }
static bool equal(const CompactTDZEnvironmentKey& a, const CompactTDZEnvironmentKey& b) { return *a.m_environment == *b.m_environment; }
static constexpr bool safeToCompareToEmptyOrDeleted = false;
static void makeDeletedValue(CompactTDZEnvironmentKey& key)
{
key.m_environment = reinterpret_cast<CompactTDZEnvironment*>(1);
}
bool isHashTableDeletedValue() const
{
return m_environment == reinterpret_cast<CompactTDZEnvironment*>(1);
}
bool isHashTableEmptyValue() const
{
return !m_environment;
}
CompactTDZEnvironment& environment()
{
RELEASE_ASSERT(!isHashTableDeletedValue());
RELEASE_ASSERT(!isHashTableEmptyValue());
return *m_environment;
}
private:
CompactTDZEnvironment* m_environment;
};
} // namespace JSC
namespace WTF {
template<typename T> struct DefaultHash;
template<> struct DefaultHash<JSC::CompactTDZEnvironmentKey> : JSC::CompactTDZEnvironmentKey { };
template<> struct HashTraits<JSC::CompactTDZEnvironmentKey> : GenericHashTraits<JSC::CompactTDZEnvironmentKey> {
static constexpr bool emptyValueIsZero = true;
static JSC::CompactTDZEnvironmentKey emptyValue() { return JSC::CompactTDZEnvironmentKey(); }
static constexpr bool hasIsEmptyValueFunction = true;
static bool isEmptyValue(JSC::CompactTDZEnvironmentKey key) { return key.isHashTableEmptyValue(); }
static void constructDeletedValue(JSC::CompactTDZEnvironmentKey& key) { JSC::CompactTDZEnvironmentKey::makeDeletedValue(key); }
static bool isDeletedValue(JSC::CompactTDZEnvironmentKey key) { return key.isHashTableDeletedValue(); }
};
} // namespace WTF
namespace JSC {
class CompactTDZEnvironmentMap : public RefCounted<CompactTDZEnvironmentMap> {
public:
class Handle {
friend class CachedCompactTDZEnvironmentMapHandle;
public:
Handle() = default;
Handle(CompactTDZEnvironment&, CompactTDZEnvironmentMap&);
Handle(Handle&& other)
{
swap(other);
}
Handle& operator=(Handle&& other)
{
Handle handle(WTFMove(other));
swap(handle);
return *this;
}
Handle(const Handle&);
Handle& operator=(const Handle& other)
{
Handle handle(other);
swap(handle);
return *this;
}
~Handle();
explicit operator bool() const { return !!m_map; }
const CompactTDZEnvironment& environment() const
{
return *m_environment;
}
private:
void swap(Handle& other)
{
std::swap(other.m_environment, m_environment);
std::swap(other.m_map, m_map);
}
CompactTDZEnvironment* m_environment { nullptr };
RefPtr<CompactTDZEnvironmentMap> m_map;
};
Handle get(const TDZEnvironment&);
private:
friend class Handle;
friend class CachedCompactTDZEnvironmentMapHandle;
Handle get(CompactTDZEnvironment*, bool& isNewEntry);
HashMap<CompactTDZEnvironmentKey, unsigned> m_map;
};
class TDZEnvironmentLink : public RefCounted<TDZEnvironmentLink> {
TDZEnvironmentLink(CompactTDZEnvironmentMap::Handle handle, RefPtr<TDZEnvironmentLink> parent)
: m_handle(WTFMove(handle))
, m_parent(WTFMove(parent))
{ }
public:
static RefPtr<TDZEnvironmentLink> create(CompactTDZEnvironmentMap::Handle handle, RefPtr<TDZEnvironmentLink> parent)
{
return adoptRef(new TDZEnvironmentLink(WTFMove(handle), WTFMove(parent)));
}
bool contains(UniquedStringImpl* impl) const { return m_handle.environment().toTDZEnvironment().contains(impl); }
TDZEnvironmentLink* parent() { return m_parent.get(); }
private:
friend class CachedTDZEnvironmentLink;
CompactTDZEnvironmentMap::Handle m_handle;
RefPtr<TDZEnvironmentLink> m_parent;
};
} // namespace JSC