#include "PropertySlot.h"
#include "Structure.h"
#include <array>
+#include <wtf/text/StringView.h>
namespace JSC {
- class JSString;
- class JSRopeString;
- class LLIntOffsetsExtractor;
+class JSString;
+class JSRopeString;
+class LLIntOffsetsExtractor;
+
+JSString* jsEmptyString(VM*);
+JSString* jsEmptyString(ExecState*);
+JSString* jsString(VM*, const String&); // returns empty string if passed null string
+JSString* jsString(ExecState*, const String&); // returns empty string if passed null string
+
+JSString* jsSingleCharacterString(VM*, UChar);
+JSString* jsSingleCharacterString(ExecState*, UChar);
+JSString* jsSubstring(VM*, const String&, unsigned offset, unsigned length);
+JSString* jsSubstring(ExecState*, const String&, unsigned offset, unsigned length);
+JSString* jsSubstring8(VM*, const String&, unsigned offset, unsigned length);
+JSString* jsSubstring8(ExecState*, const String&, unsigned offset, unsigned length);
+
+// Non-trivial strings are two or more characters long.
+// These functions are faster than just calling jsString.
+JSString* jsNontrivialString(VM*, const String&);
+JSString* jsNontrivialString(ExecState*, const String&);
+JSString* jsNontrivialString(ExecState*, String&&);
+
+// Should be used for strings that are owned by an object that will
+// likely outlive the JSValue this makes, such as the parse tree or a
+// DOM object that contains a String
+JSString* jsOwnedString(VM*, const String&);
+JSString* jsOwnedString(ExecState*, const String&);
+
+JSRopeString* jsStringBuilder(VM*);
+
+bool isJSString(JSValue);
+JSString* asString(JSValue);
+
+struct StringViewWithUnderlyingString {
+ StringView view;
+ String underlyingString;
+};
+
+class JSString : public JSCell {
+public:
+ friend class JIT;
+ friend class VM;
+ friend class SpecializedThunkJIT;
+ friend class JSRopeString;
+ friend class MarkStack;
+ friend class SlotVisitor;
+ friend struct ThunkHelpers;
+
+ typedef JSCell Base;
+ static const unsigned StructureFlags = Base::StructureFlags | OverridesGetOwnPropertySlot | InterceptsGetOwnPropertySlotByIndexEvenWhenLengthIsNotZero | StructureIsImmortal;
+
+ static const bool needsDestruction = true;
+ static void destroy(JSCell*);
+
+private:
+ JSString(VM& vm, PassRefPtr<StringImpl> value)
+ : JSCell(vm, vm.stringStructure.get())
+ , m_flags(0)
+ , m_value(value)
+ {
+ }
- JSString* jsEmptyString(VM*);
- JSString* jsEmptyString(ExecState*);
- JSString* jsString(VM*, const String&); // returns empty string if passed null string
- JSString* jsString(ExecState*, const String&); // returns empty string if passed null string
+ JSString(VM& vm)
+ : JSCell(vm, vm.stringStructure.get())
+ , m_flags(0)
+ {
+ }
- JSString* jsSingleCharacterString(VM*, UChar);
- JSString* jsSingleCharacterString(ExecState*, UChar);
- JSString* jsSingleCharacterSubstring(ExecState*, const String&, unsigned offset);
- JSString* jsSubstring(VM*, const String&, unsigned offset, unsigned length);
- JSString* jsSubstring(ExecState*, const String&, unsigned offset, unsigned length);
+ void finishCreation(VM& vm, size_t length)
+ {
+ ASSERT(!m_value.isNull());
+ Base::finishCreation(vm);
+ m_length = length;
+ setIs8Bit(m_value.impl()->is8Bit());
+ vm.m_newStringsSinceLastHashCons++;
+ }
- // Non-trivial strings are two or more characters long.
- // These functions are faster than just calling jsString.
- JSString* jsNontrivialString(VM*, const String&);
- JSString* jsNontrivialString(ExecState*, const String&);
+ void finishCreation(VM& vm, size_t length, size_t cost)
+ {
+ ASSERT(!m_value.isNull());
+ Base::finishCreation(vm);
+ m_length = length;
+ setIs8Bit(m_value.impl()->is8Bit());
+ Heap::heap(this)->reportExtraMemoryAllocated(cost);
+ vm.m_newStringsSinceLastHashCons++;
+ }
- // Should be used for strings that are owned by an object that will
- // likely outlive the JSValue this makes, such as the parse tree or a
- // DOM object that contains a String
- JSString* jsOwnedString(VM*, const String&);
- JSString* jsOwnedString(ExecState*, const String&);
+protected:
+ void finishCreation(VM& vm)
+ {
+ Base::finishCreation(vm);
+ m_length = 0;
+ setIs8Bit(true);
+ vm.m_newStringsSinceLastHashCons++;
+ }
- JSRopeString* jsStringBuilder(VM*);
+public:
+ static JSString* create(VM& vm, PassRefPtr<StringImpl> value)
+ {
+ ASSERT(value);
+ int32_t length = value->length();
+ RELEASE_ASSERT(length >= 0);
+ size_t cost = value->cost();
+ JSString* newString = new (NotNull, allocateCell<JSString>(vm.heap)) JSString(vm, value);
+ newString->finishCreation(vm, length, cost);
+ return newString;
+ }
+ static JSString* createHasOtherOwner(VM& vm, PassRefPtr<StringImpl> value)
+ {
+ ASSERT(value);
+ size_t length = value->length();
+ JSString* newString = new (NotNull, allocateCell<JSString>(vm.heap)) JSString(vm, value);
+ newString->finishCreation(vm, length);
+ return newString;
+ }
- class JSString : public JSCell {
- public:
- friend class JIT;
- friend class VM;
- friend class SpecializedThunkJIT;
- friend class JSRopeString;
- friend class MarkStack;
- friend class SlotVisitor;
- friend struct ThunkHelpers;
+ Identifier toIdentifier(ExecState*) const;
+ AtomicString toAtomicString(ExecState*) const;
+ RefPtr<AtomicStringImpl> toExistingAtomicString(ExecState*) const;
- typedef JSCell Base;
+ class SafeView;
+ SafeView view(ExecState*) const;
+ StringViewWithUnderlyingString viewWithUnderlyingString(ExecState&) const;
- static const bool needsDestruction = true;
- static const bool hasImmortalStructure = true;
- static void destroy(JSCell*);
+ const String& value(ExecState*) const;
+ const String& tryGetValue() const;
+ const StringImpl* tryGetValueImpl() const;
+ unsigned length() const { return m_length; }
- private:
- JSString(VM& vm, PassRefPtr<StringImpl> value)
- : JSCell(vm, vm.stringStructure.get())
- , m_flags(0)
- , m_value(value)
- {
- }
-
- JSString(VM& vm)
- : JSCell(vm, vm.stringStructure.get())
- , m_flags(0)
- {
- }
+ JSValue toPrimitive(ExecState*, PreferredPrimitiveType) const;
+ bool toBoolean() const { return !!m_length; }
+ bool getPrimitiveNumber(ExecState*, double& number, JSValue&) const;
+ JSObject* toObject(ExecState*, JSGlobalObject*) const;
+ double toNumber(ExecState*) const;
- void finishCreation(VM& vm, size_t length)
- {
- ASSERT(!m_value.isNull());
- Base::finishCreation(vm);
- m_length = length;
- setIs8Bit(m_value.impl()->is8Bit());
- vm.m_newStringsSinceLastHashCons++;
- }
-
- void finishCreation(VM& vm, size_t length, size_t cost)
- {
- ASSERT(!m_value.isNull());
- Base::finishCreation(vm);
- m_length = length;
- setIs8Bit(m_value.impl()->is8Bit());
- Heap::heap(this)->reportExtraMemoryCost(cost);
- vm.m_newStringsSinceLastHashCons++;
- }
+ bool getStringPropertySlot(ExecState*, PropertyName, PropertySlot&);
+ bool getStringPropertySlot(ExecState*, unsigned propertyName, PropertySlot&);
+ bool getStringPropertyDescriptor(ExecState*, PropertyName, PropertyDescriptor&);
- protected:
- void finishCreation(VM& vm)
- {
- Base::finishCreation(vm);
- m_length = 0;
- setIs8Bit(true);
- vm.m_newStringsSinceLastHashCons++;
- }
-
- public:
- static JSString* create(VM& vm, PassRefPtr<StringImpl> value)
- {
- ASSERT(value);
- int32_t length = value->length();
- RELEASE_ASSERT(length >= 0);
- size_t cost = value->cost();
- JSString* newString = new (NotNull, allocateCell<JSString>(vm.heap)) JSString(vm, value);
- newString->finishCreation(vm, length, cost);
- return newString;
- }
- static JSString* createHasOtherOwner(VM& vm, PassRefPtr<StringImpl> value)
- {
- ASSERT(value);
- size_t length = value->length();
- JSString* newString = new (NotNull, allocateCell<JSString>(vm.heap)) JSString(vm, value);
- newString->finishCreation(vm, length);
- return newString;
- }
+ bool canGetIndex(unsigned i) { return i < m_length; }
+ JSString* getIndex(ExecState*, unsigned);
- Identifier toIdentifier(ExecState*) const;
- AtomicString toAtomicString(ExecState*) const;
- AtomicStringImpl* toExistingAtomicString(ExecState*) const;
- const String& value(ExecState*) const;
- const String& tryGetValue() const;
- const StringImpl* tryGetValueImpl() const;
- unsigned length() const { return m_length; }
-
- JSValue toPrimitive(ExecState*, PreferredPrimitiveType) const;
- JS_EXPORT_PRIVATE bool toBoolean() const;
- bool getPrimitiveNumber(ExecState*, double& number, JSValue&) const;
- JSObject* toObject(ExecState*, JSGlobalObject*) const;
- double toNumber(ExecState*) const;
-
- bool getStringPropertySlot(ExecState*, PropertyName, PropertySlot&);
- bool getStringPropertySlot(ExecState*, unsigned propertyName, PropertySlot&);
- bool getStringPropertyDescriptor(ExecState*, PropertyName, PropertyDescriptor&);
-
- bool canGetIndex(unsigned i) { return i < m_length; }
- JSString* getIndex(ExecState*, unsigned);
-
- static Structure* createStructure(VM& vm, JSGlobalObject* globalObject, JSValue proto)
- {
- return Structure::create(vm, globalObject, proto, TypeInfo(StringType, StructureFlags), info());
- }
-
- static size_t offsetOfLength() { return OBJECT_OFFSETOF(JSString, m_length); }
- static size_t offsetOfFlags() { return OBJECT_OFFSETOF(JSString, m_flags); }
- static size_t offsetOfValue() { return OBJECT_OFFSETOF(JSString, m_value); }
-
- DECLARE_EXPORT_INFO;
-
- static void dumpToStream(const JSCell*, PrintStream&);
- static void visitChildren(JSCell*, SlotVisitor&);
-
- enum {
- HashConsLock = 1u << 2,
- IsHashConsSingleton = 1u << 1,
- Is8Bit = 1u
- };
-
- protected:
- static const unsigned StructureFlags = OverridesGetOwnPropertySlot | InterceptsGetOwnPropertySlotByIndexEvenWhenLengthIsNotZero | StructureIsImmortal;
+ static Structure* createStructure(VM& vm, JSGlobalObject* globalObject, JSValue proto)
+ {
+ return Structure::create(vm, globalObject, proto, TypeInfo(StringType, StructureFlags), info());
+ }
- friend class JSValue;
-
- bool isRope() const { return m_value.isNull(); }
- bool is8Bit() const { return m_flags & Is8Bit; }
- void setIs8Bit(bool flag)
- {
- if (flag)
- m_flags |= Is8Bit;
- else
- m_flags &= ~Is8Bit;
- }
- bool shouldTryHashCons();
- bool isHashConsSingleton() const { return m_flags & IsHashConsSingleton; }
- void clearHashConsSingleton() { m_flags &= ~IsHashConsSingleton; }
- void setHashConsSingleton() { m_flags |= IsHashConsSingleton; }
- bool tryHashConsLock();
- void releaseHashConsLock();
-
- unsigned m_flags;
-
- // A string is represented either by a String or a rope of fibers.
- unsigned m_length;
- mutable String m_value;
+ static size_t offsetOfLength() { return OBJECT_OFFSETOF(JSString, m_length); }
+ static size_t offsetOfFlags() { return OBJECT_OFFSETOF(JSString, m_flags); }
+ static size_t offsetOfValue() { return OBJECT_OFFSETOF(JSString, m_value); }
- private:
- friend class LLIntOffsetsExtractor;
-
- static JSValue toThis(JSCell*, ExecState*, ECMAMode);
+ DECLARE_EXPORT_INFO;
- String& string() { ASSERT(!isRope()); return m_value; }
+ static void dumpToStream(const JSCell*, PrintStream&);
+ static void visitChildren(JSCell*, SlotVisitor&);
- friend JSValue jsString(ExecState*, JSString*, JSString*);
- friend JSString* jsSubstring(ExecState*, JSString*, unsigned offset, unsigned length);
+ enum {
+ HashConsLock = 1u << 2,
+ IsHashConsSingleton = 1u << 1,
+ Is8Bit = 1u
};
- class JSRopeString : public JSString {
- friend class JSString;
+protected:
+ friend class JSValue;
- friend JSRopeString* jsStringBuilder(VM*);
+ bool isRope() const { return m_value.isNull(); }
+ bool isSubstring() const;
+ bool is8Bit() const { return m_flags & Is8Bit; }
+ void setIs8Bit(bool flag) const
+ {
+ if (flag)
+ m_flags |= Is8Bit;
+ else
+ m_flags &= ~Is8Bit;
+ }
+ bool shouldTryHashCons();
+ bool isHashConsSingleton() const { return m_flags & IsHashConsSingleton; }
+ void clearHashConsSingleton() { m_flags &= ~IsHashConsSingleton; }
+ void setHashConsSingleton() { m_flags |= IsHashConsSingleton; }
+ bool tryHashConsLock();
+ void releaseHashConsLock();
- class RopeBuilder {
- public:
- RopeBuilder(VM& vm)
- : m_vm(vm)
- , m_jsString(jsStringBuilder(&vm))
- , m_index(0)
- {
- }
+ mutable unsigned m_flags;
- bool append(JSString* jsString)
- {
- if (m_index == JSRopeString::s_maxInternalRopeLength)
- expand();
- if (static_cast<int32_t>(m_jsString->length() + jsString->length()) < 0) {
- m_jsString = nullptr;
- return false;
- }
- m_jsString->append(m_vm, m_index++, jsString);
- return true;
- }
+ // A string is represented either by a String or a rope of fibers.
+ unsigned m_length;
+ mutable String m_value;
- JSRopeString* release()
- {
- RELEASE_ASSERT(m_jsString);
- JSRopeString* tmp = m_jsString;
- m_jsString = 0;
- return tmp;
- }
+private:
+ friend class LLIntOffsetsExtractor;
- unsigned length() const { return m_jsString->m_length; }
+ static JSValue toThis(JSCell*, ExecState*, ECMAMode);
- private:
- void expand();
-
- VM& m_vm;
- JSRopeString* m_jsString;
- size_t m_index;
- };
-
- private:
- JSRopeString(VM& vm)
- : JSString(vm)
- {
- }
+ String& string() { ASSERT(!isRope()); return m_value; }
+ StringView unsafeView(ExecState&) const;
- void finishCreation(VM& vm, JSString* s1, JSString* s2)
- {
- Base::finishCreation(vm);
- m_length = s1->length() + s2->length();
- setIs8Bit(s1->is8Bit() && s2->is8Bit());
- m_fibers[0].set(vm, this, s1);
- m_fibers[1].set(vm, this, s2);
- }
-
- void finishCreation(VM& vm, JSString* s1, JSString* s2, JSString* s3)
- {
- Base::finishCreation(vm);
- m_length = s1->length() + s2->length() + s3->length();
- setIs8Bit(s1->is8Bit() && s2->is8Bit() && s3->is8Bit());
- m_fibers[0].set(vm, this, s1);
- m_fibers[1].set(vm, this, s2);
- m_fibers[2].set(vm, this, s3);
- }
+ friend JSValue jsString(ExecState*, JSString*, JSString*);
+ friend JSString* jsSubstring(ExecState*, JSString*, unsigned offset, unsigned length);
+};
- void finishCreation(VM& vm)
- {
- JSString::finishCreation(vm);
- }
+class JSRopeString final : public JSString {
+ friend class JSString;
- void append(VM& vm, size_t index, JSString* jsString)
- {
- m_fibers[index].set(vm, this, jsString);
- m_length += jsString->m_length;
- RELEASE_ASSERT(static_cast<int32_t>(m_length) >= 0);
- setIs8Bit(is8Bit() && jsString->is8Bit());
- }
+ friend JSRopeString* jsStringBuilder(VM*);
- static JSRopeString* createNull(VM& vm)
+public:
+ class RopeBuilder {
+ public:
+ RopeBuilder(VM& vm)
+ : m_vm(vm)
+ , m_jsString(jsStringBuilder(&vm))
+ , m_index(0)
{
- JSRopeString* newString = new (NotNull, allocateCell<JSRopeString>(vm.heap)) JSRopeString(vm);
- newString->finishCreation(vm);
- return newString;
}
- public:
- static JSString* create(VM& vm, JSString* s1, JSString* s2)
+ bool append(JSString* jsString)
{
- JSRopeString* newString = new (NotNull, allocateCell<JSRopeString>(vm.heap)) JSRopeString(vm);
- newString->finishCreation(vm, s1, s2);
- return newString;
+ if (m_index == JSRopeString::s_maxInternalRopeLength)
+ expand();
+ if (static_cast<int32_t>(m_jsString->length() + jsString->length()) < 0) {
+ m_jsString = nullptr;
+ return false;
+ }
+ m_jsString->append(m_vm, m_index++, jsString);
+ return true;
}
- static JSString* create(VM& vm, JSString* s1, JSString* s2, JSString* s3)
+
+ JSRopeString* release()
{
- JSRopeString* newString = new (NotNull, allocateCell<JSRopeString>(vm.heap)) JSRopeString(vm);
- newString->finishCreation(vm, s1, s2, s3);
- return newString;
+ RELEASE_ASSERT(m_jsString);
+ JSRopeString* tmp = m_jsString;
+ m_jsString = 0;
+ return tmp;
}
- void visitFibers(SlotVisitor&);
-
- static ptrdiff_t offsetOfFibers() { return OBJECT_OFFSETOF(JSRopeString, m_fibers); }
+ unsigned length() const { return m_jsString->m_length; }
- static const unsigned s_maxInternalRopeLength = 3;
-
private:
- friend JSValue jsStringFromRegisterArray(ExecState*, Register*, unsigned);
- friend JSValue jsStringFromArguments(ExecState*, JSValue);
-
- JS_EXPORT_PRIVATE void resolveRope(ExecState*) const;
- JS_EXPORT_PRIVATE void resolveRopeToAtomicString(ExecState*) const;
- JS_EXPORT_PRIVATE AtomicStringImpl* resolveRopeToExistingAtomicString(ExecState*) const;
- void resolveRopeSlowCase8(LChar*) const;
- void resolveRopeSlowCase(UChar*) const;
- void outOfMemory(ExecState*) const;
- void resolveRopeInternal8(LChar*) const;
- void resolveRopeInternal16(UChar*) const;
- void clearFibers() const;
-
- JS_EXPORT_PRIVATE JSString* getIndexSlowCase(ExecState*, unsigned);
-
- mutable std::array<WriteBarrier<JSString>, s_maxInternalRopeLength> m_fibers;
- };
+ void expand();
+ VM& m_vm;
+ JSRopeString* m_jsString;
+ size_t m_index;
+ };
- inline const StringImpl* JSString::tryGetValueImpl() const
+private:
+ JSRopeString(VM& vm)
+ : JSString(vm)
{
- return m_value.impl();
}
- JSString* asString(JSValue);
-
- inline JSString* asString(JSValue value)
+ void finishCreation(VM& vm, JSString* s1, JSString* s2)
{
- ASSERT(value.asCell()->isString());
- return jsCast<JSString*>(value.asCell());
+ Base::finishCreation(vm);
+ m_length = s1->length() + s2->length();
+ setIs8Bit(s1->is8Bit() && s2->is8Bit());
+ setIsSubstring(false);
+ fiber(0).set(vm, this, s1);
+ fiber(1).set(vm, this, s2);
+ fiber(2).clear();
}
- inline JSString* jsEmptyString(VM* vm)
+ void finishCreation(VM& vm, JSString* s1, JSString* s2, JSString* s3)
{
- return vm->smallStrings.emptyString();
+ Base::finishCreation(vm);
+ m_length = s1->length() + s2->length() + s3->length();
+ setIs8Bit(s1->is8Bit() && s2->is8Bit() && s3->is8Bit());
+ setIsSubstring(false);
+ fiber(0).set(vm, this, s1);
+ fiber(1).set(vm, this, s2);
+ fiber(2).set(vm, this, s3);
}
- ALWAYS_INLINE JSString* jsSingleCharacterString(VM* vm, UChar c)
+ void finishCreation(ExecState& exec, JSString& base, unsigned offset, unsigned length)
{
- if (c <= maxSingleCharacterString)
- return vm->smallStrings.singleCharacterString(c);
- return JSString::create(*vm, String(&c, 1).impl());
+ VM& vm = exec.vm();
+ Base::finishCreation(vm);
+ ASSERT(!sumOverflows<int32_t>(offset, length));
+ ASSERT(offset + length <= base.length());
+ m_length = length;
+ setIs8Bit(base.is8Bit());
+ setIsSubstring(true);
+ if (base.isSubstring()) {
+ JSRopeString& baseRope = static_cast<JSRopeString&>(base);
+ substringBase().set(vm, this, baseRope.substringBase().get());
+ substringOffset() = baseRope.substringOffset() + offset;
+ } else {
+ substringBase().set(vm, this, &base);
+ substringOffset() = offset;
+
+ // For now, let's not allow substrings with a rope base.
+ // Resolve non-substring rope bases so we don't have to deal with it.
+ // FIXME: Evaluate if this would be worth adding more branches.
+ if (base.isRope())
+ static_cast<JSRopeString&>(base).resolveRope(&exec);
+ }
}
- ALWAYS_INLINE JSString* jsSingleCharacterSubstring(ExecState* exec, const String& s, unsigned offset)
+ void finishCreation(VM& vm)
{
- VM* vm = &exec->vm();
- ASSERT(offset < static_cast<unsigned>(s.length()));
- UChar c = s.characterAt(offset);
- if (c <= maxSingleCharacterString)
- return vm->smallStrings.singleCharacterString(c);
- return JSString::create(*vm, StringImpl::createSubstringSharingImpl(s.impl(), offset, 1));
+ JSString::finishCreation(vm);
+ setIsSubstring(false);
+ fiber(0).clear();
+ fiber(1).clear();
+ fiber(2).clear();
}
- inline JSString* jsNontrivialString(VM* vm, const String& s)
+ void append(VM& vm, size_t index, JSString* jsString)
{
- ASSERT(s.length() > 1);
- return JSString::create(*vm, s.impl());
+ fiber(index).set(vm, this, jsString);
+ m_length += jsString->m_length;
+ RELEASE_ASSERT(static_cast<int32_t>(m_length) >= 0);
+ setIs8Bit(is8Bit() && jsString->is8Bit());
}
- ALWAYS_INLINE Identifier JSString::toIdentifier(ExecState* exec) const
+ static JSRopeString* createNull(VM& vm)
{
- return Identifier(exec, toAtomicString(exec));
+ JSRopeString* newString = new (NotNull, allocateCell<JSRopeString>(vm.heap)) JSRopeString(vm);
+ newString->finishCreation(vm);
+ return newString;
}
- ALWAYS_INLINE AtomicString JSString::toAtomicString(ExecState* exec) const
+public:
+ static JSString* create(VM& vm, JSString* s1, JSString* s2)
{
- if (isRope())
- static_cast<const JSRopeString*>(this)->resolveRopeToAtomicString(exec);
- return AtomicString(m_value);
+ JSRopeString* newString = new (NotNull, allocateCell<JSRopeString>(vm.heap)) JSRopeString(vm);
+ newString->finishCreation(vm, s1, s2);
+ return newString;
}
-
- ALWAYS_INLINE AtomicStringImpl* JSString::toExistingAtomicString(ExecState* exec) const
+ static JSString* create(VM& vm, JSString* s1, JSString* s2, JSString* s3)
{
- if (isRope())
- return static_cast<const JSRopeString*>(this)->resolveRopeToExistingAtomicString(exec);
- if (m_value.impl()->isAtomic())
- return static_cast<AtomicStringImpl*>(m_value.impl());
- if (AtomicStringImpl* existingAtomicString = AtomicString::find(m_value.impl())) {
- m_value = *existingAtomicString;
- return existingAtomicString;
- }
- return nullptr;
+ JSRopeString* newString = new (NotNull, allocateCell<JSRopeString>(vm.heap)) JSRopeString(vm);
+ newString->finishCreation(vm, s1, s2, s3);
+ return newString;
}
- inline const String& JSString::value(ExecState* exec) const
+ static JSString* create(ExecState& exec, JSString& base, unsigned offset, unsigned length)
{
- if (isRope())
- static_cast<const JSRopeString*>(this)->resolveRope(exec);
- return m_value;
+ JSRopeString* newString = new (NotNull, allocateCell<JSRopeString>(exec.vm().heap)) JSRopeString(exec.vm());
+ newString->finishCreation(exec, base, offset, length);
+ return newString;
}
- inline const String& JSString::tryGetValue() const
- {
- if (isRope())
- static_cast<const JSRopeString*>(this)->resolveRope(0);
- return m_value;
- }
+ void visitFibers(SlotVisitor&);
- inline JSString* JSString::getIndex(ExecState* exec, unsigned i)
- {
- ASSERT(canGetIndex(i));
- if (isRope())
- return static_cast<JSRopeString*>(this)->getIndexSlowCase(exec, i);
- ASSERT(i < m_value.length());
- return jsSingleCharacterSubstring(exec, m_value, i);
- }
+ static ptrdiff_t offsetOfFibers() { return OBJECT_OFFSETOF(JSRopeString, u); }
- inline JSString* jsString(VM* vm, const String& s)
+ static const unsigned s_maxInternalRopeLength = 3;
+
+private:
+ friend JSValue jsStringFromRegisterArray(ExecState*, Register*, unsigned);
+ friend JSValue jsStringFromArguments(ExecState*, JSValue);
+
+ JS_EXPORT_PRIVATE void resolveRope(ExecState*) const;
+ JS_EXPORT_PRIVATE void resolveRopeToAtomicString(ExecState*) const;
+ JS_EXPORT_PRIVATE RefPtr<AtomicStringImpl> resolveRopeToExistingAtomicString(ExecState*) const;
+ void resolveRopeSlowCase8(LChar*) const;
+ void resolveRopeSlowCase(UChar*) const;
+ void outOfMemory(ExecState*) const;
+ void resolveRopeInternal8(LChar*) const;
+ void resolveRopeInternal8NoSubstring(LChar*) const;
+ void resolveRopeInternal16(UChar*) const;
+ void resolveRopeInternal16NoSubstring(UChar*) const;
+ void clearFibers() const;
+ StringView unsafeView(ExecState&) const;
+ StringViewWithUnderlyingString viewWithUnderlyingString(ExecState&) const;
+
+ WriteBarrierBase<JSString>& fiber(unsigned i) const
{
- int size = s.length();
- if (!size)
- return vm->smallStrings.emptyString();
- if (size == 1) {
- UChar c = s.characterAt(0);
- if (c <= maxSingleCharacterString)
- return vm->smallStrings.singleCharacterString(c);
- }
- return JSString::create(*vm, s.impl());
+ ASSERT(!isSubstring());
+ ASSERT(i < s_maxInternalRopeLength);
+ return u[i].string;
}
- inline JSString* jsSubstring(ExecState* exec, JSString* s, unsigned offset, unsigned length)
+ WriteBarrierBase<JSString>& substringBase() const
{
- ASSERT(offset <= static_cast<unsigned>(s->length()));
- ASSERT(length <= static_cast<unsigned>(s->length()));
- ASSERT(offset + length <= static_cast<unsigned>(s->length()));
- VM* vm = &exec->vm();
- if (!length)
- return vm->smallStrings.emptyString();
- return jsSubstring(vm, s->value(exec), offset, length);
+ return u[1].string;
}
- inline JSString* jsSubstring8(VM* vm, const String& s, unsigned offset, unsigned length)
+ uintptr_t& substringOffset() const
{
- ASSERT(offset <= static_cast<unsigned>(s.length()));
- ASSERT(length <= static_cast<unsigned>(s.length()));
- ASSERT(offset + length <= static_cast<unsigned>(s.length()));
- if (!length)
- return vm->smallStrings.emptyString();
- if (length == 1) {
- UChar c = s.characterAt(offset);
- if (c <= maxSingleCharacterString)
- return vm->smallStrings.singleCharacterString(c);
- }
- return JSString::createHasOtherOwner(*vm, StringImpl::createSubstringSharingImpl8(s.impl(), offset, length));
+ return u[2].number;
}
- inline JSString* jsSubstring(VM* vm, const String& s, unsigned offset, unsigned length)
+ static uintptr_t notSubstringSentinel()
{
- ASSERT(offset <= static_cast<unsigned>(s.length()));
- ASSERT(length <= static_cast<unsigned>(s.length()));
- ASSERT(offset + length <= static_cast<unsigned>(s.length()));
- if (!length)
- return vm->smallStrings.emptyString();
- if (length == 1) {
- UChar c = s.characterAt(offset);
- if (c <= maxSingleCharacterString)
- return vm->smallStrings.singleCharacterString(c);
- }
- return JSString::createHasOtherOwner(*vm, StringImpl::createSubstringSharingImpl(s.impl(), offset, length));
+ return 0;
}
- inline JSString* jsOwnedString(VM* vm, const String& s)
+ static uintptr_t substringSentinel()
{
- int size = s.length();
- if (!size)
- return vm->smallStrings.emptyString();
- if (size == 1) {
- UChar c = s.characterAt(0);
- if (c <= maxSingleCharacterString)
- return vm->smallStrings.singleCharacterString(c);
- }
- return JSString::createHasOtherOwner(*vm, s.impl());
+ return 1;
}
- inline JSRopeString* jsStringBuilder(VM* vm)
+ bool isSubstring() const
{
- return JSRopeString::createNull(*vm);
+ return u[0].number == substringSentinel();
}
- inline JSString* jsEmptyString(ExecState* exec) { return jsEmptyString(&exec->vm()); }
- inline JSString* jsString(ExecState* exec, const String& s) { return jsString(&exec->vm(), s); }
- inline JSString* jsSingleCharacterString(ExecState* exec, UChar c) { return jsSingleCharacterString(&exec->vm(), c); }
- inline JSString* jsSubstring8(ExecState* exec, const String& s, unsigned offset, unsigned length) { return jsSubstring8(&exec->vm(), s, offset, length); }
- inline JSString* jsSubstring(ExecState* exec, const String& s, unsigned offset, unsigned length) { return jsSubstring(&exec->vm(), s, offset, length); }
- inline JSString* jsNontrivialString(ExecState* exec, const String& s) { return jsNontrivialString(&exec->vm(), s); }
- inline JSString* jsOwnedString(ExecState* exec, const String& s) { return jsOwnedString(&exec->vm(), s); }
-
- JS_EXPORT_PRIVATE JSString* jsStringWithCacheSlowCase(VM&, StringImpl&);
-
- ALWAYS_INLINE JSString* jsStringWithCache(ExecState* exec, const String& s)
+ void setIsSubstring(bool isSubstring)
{
- VM& vm = exec->vm();
- StringImpl* stringImpl = s.impl();
- if (!stringImpl || !stringImpl->length())
- return jsEmptyString(&vm);
-
- if (stringImpl->length() == 1) {
- UChar singleCharacter = (*stringImpl)[0u];
- if (singleCharacter <= maxSingleCharacterString)
- return vm.smallStrings.singleCharacterString(static_cast<unsigned char>(singleCharacter));
- }
+ u[0].number = isSubstring ? substringSentinel() : notSubstringSentinel();
+ }
- if (JSString* lastCachedString = vm.lastCachedString.get()) {
- if (lastCachedString->tryGetValueImpl() == stringImpl)
- return lastCachedString;
- }
+ mutable union {
+ uintptr_t number;
+ WriteBarrierBase<JSString> string;
+ } u[s_maxInternalRopeLength];
+};
+
+class JSString::SafeView {
+public:
+ SafeView();
+ explicit SafeView(ExecState&, const JSString&);
+ operator StringView() const;
+ StringView get() const;
+
+private:
+ ExecState* m_state { nullptr };
+
+ // The following pointer is marked "volatile" to make the compiler leave it on the stack
+ // or in a register as long as this object is alive, even after the last use of the pointer.
+ // That's needed to prevent garbage collecting the string and possibly deleting the block
+ // with the characters in it, and then using the StringView after that.
+ const JSString* volatile m_string { nullptr };
+};
+
+JS_EXPORT_PRIVATE JSString* jsStringWithCacheSlowCase(VM&, StringImpl&);
+
+inline const StringImpl* JSString::tryGetValueImpl() const
+{
+ return m_value.impl();
+}
+
+inline JSString* asString(JSValue value)
+{
+ ASSERT(value.asCell()->isString());
+ return jsCast<JSString*>(value.asCell());
+}
+
+inline JSString* jsEmptyString(VM* vm)
+{
+ return vm->smallStrings.emptyString();
+}
+
+ALWAYS_INLINE JSString* jsSingleCharacterString(VM* vm, UChar c)
+{
+ if (c <= maxSingleCharacterString)
+ return vm->smallStrings.singleCharacterString(c);
+ return JSString::create(*vm, String(&c, 1).impl());
+}
+
+inline JSString* jsNontrivialString(VM* vm, const String& s)
+{
+ ASSERT(s.length() > 1);
+ return JSString::create(*vm, s.impl());
+}
+
+inline JSString* jsNontrivialString(VM* vm, String&& s)
+{
+ ASSERT(s.length() > 1);
+ return JSString::create(*vm, s.releaseImpl());
+}
+
+ALWAYS_INLINE Identifier JSString::toIdentifier(ExecState* exec) const
+{
+ return Identifier::fromString(exec, toAtomicString(exec));
+}
+
+ALWAYS_INLINE AtomicString JSString::toAtomicString(ExecState* exec) const
+{
+ if (isRope())
+ static_cast<const JSRopeString*>(this)->resolveRopeToAtomicString(exec);
+ return AtomicString(m_value);
+}
+
+ALWAYS_INLINE RefPtr<AtomicStringImpl> JSString::toExistingAtomicString(ExecState* exec) const
+{
+ if (isRope())
+ return static_cast<const JSRopeString*>(this)->resolveRopeToExistingAtomicString(exec);
+ if (m_value.impl()->isAtomic())
+ return static_cast<AtomicStringImpl*>(m_value.impl());
+ return AtomicStringImpl::lookUp(m_value.impl());
+}
+
+inline const String& JSString::value(ExecState* exec) const
+{
+ if (isRope())
+ static_cast<const JSRopeString*>(this)->resolveRope(exec);
+ return m_value;
+}
+
+inline const String& JSString::tryGetValue() const
+{
+ if (isRope())
+ static_cast<const JSRopeString*>(this)->resolveRope(0);
+ return m_value;
+}
+
+inline JSString* JSString::getIndex(ExecState* exec, unsigned i)
+{
+ ASSERT(canGetIndex(i));
+ return jsSingleCharacterString(exec, unsafeView(*exec)[i]);
+}
+
+inline JSString* jsString(VM* vm, const String& s)
+{
+ int size = s.length();
+ if (!size)
+ return vm->smallStrings.emptyString();
+ if (size == 1) {
+ UChar c = s.characterAt(0);
+ if (c <= maxSingleCharacterString)
+ return vm->smallStrings.singleCharacterString(c);
+ }
+ return JSString::create(*vm, s.impl());
+}
+
+inline JSString* jsSubstring(ExecState* exec, JSString* s, unsigned offset, unsigned length)
+{
+ ASSERT(offset <= static_cast<unsigned>(s->length()));
+ ASSERT(length <= static_cast<unsigned>(s->length()));
+ ASSERT(offset + length <= static_cast<unsigned>(s->length()));
+ VM& vm = exec->vm();
+ if (!length)
+ return vm.smallStrings.emptyString();
+ if (!offset && length == s->length())
+ return s;
+ return JSRopeString::create(*exec, *s, offset, length);
+}
+
+inline JSString* jsSubstring8(VM* vm, const String& s, unsigned offset, unsigned length)
+{
+ ASSERT(offset <= static_cast<unsigned>(s.length()));
+ ASSERT(length <= static_cast<unsigned>(s.length()));
+ ASSERT(offset + length <= static_cast<unsigned>(s.length()));
+ if (!length)
+ return vm->smallStrings.emptyString();
+ if (length == 1) {
+ UChar c = s.characterAt(offset);
+ if (c <= maxSingleCharacterString)
+ return vm->smallStrings.singleCharacterString(c);
+ }
+ return JSString::createHasOtherOwner(*vm, StringImpl::createSubstringSharingImpl8(s.impl(), offset, length));
+}
+
+inline JSString* jsSubstring(VM* vm, const String& s, unsigned offset, unsigned length)
+{
+ ASSERT(offset <= static_cast<unsigned>(s.length()));
+ ASSERT(length <= static_cast<unsigned>(s.length()));
+ ASSERT(offset + length <= static_cast<unsigned>(s.length()));
+ if (!length)
+ return vm->smallStrings.emptyString();
+ if (length == 1) {
+ UChar c = s.characterAt(offset);
+ if (c <= maxSingleCharacterString)
+ return vm->smallStrings.singleCharacterString(c);
+ }
+ return JSString::createHasOtherOwner(*vm, StringImpl::createSubstringSharingImpl(s.impl(), offset, length));
+}
- return jsStringWithCacheSlowCase(vm, *stringImpl);
+inline JSString* jsOwnedString(VM* vm, const String& s)
+{
+ int size = s.length();
+ if (!size)
+ return vm->smallStrings.emptyString();
+ if (size == 1) {
+ UChar c = s.characterAt(0);
+ if (c <= maxSingleCharacterString)
+ return vm->smallStrings.singleCharacterString(c);
+ }
+ return JSString::createHasOtherOwner(*vm, s.impl());
+}
+
+inline JSRopeString* jsStringBuilder(VM* vm)
+{
+ return JSRopeString::createNull(*vm);
+}
+
+inline JSString* jsEmptyString(ExecState* exec) { return jsEmptyString(&exec->vm()); }
+inline JSString* jsString(ExecState* exec, const String& s) { return jsString(&exec->vm(), s); }
+inline JSString* jsSingleCharacterString(ExecState* exec, UChar c) { return jsSingleCharacterString(&exec->vm(), c); }
+inline JSString* jsSubstring8(ExecState* exec, const String& s, unsigned offset, unsigned length) { return jsSubstring8(&exec->vm(), s, offset, length); }
+inline JSString* jsSubstring(ExecState* exec, const String& s, unsigned offset, unsigned length) { return jsSubstring(&exec->vm(), s, offset, length); }
+inline JSString* jsNontrivialString(ExecState* exec, const String& s) { return jsNontrivialString(&exec->vm(), s); }
+inline JSString* jsNontrivialString(ExecState* exec, String&& s) { return jsNontrivialString(&exec->vm(), WTF::move(s)); }
+inline JSString* jsOwnedString(ExecState* exec, const String& s) { return jsOwnedString(&exec->vm(), s); }
+
+ALWAYS_INLINE JSString* jsStringWithCache(ExecState* exec, const String& s)
+{
+ VM& vm = exec->vm();
+ StringImpl* stringImpl = s.impl();
+ if (!stringImpl || !stringImpl->length())
+ return jsEmptyString(&vm);
+
+ if (stringImpl->length() == 1) {
+ UChar singleCharacter = (*stringImpl)[0u];
+ if (singleCharacter <= maxSingleCharacterString)
+ return vm.smallStrings.singleCharacterString(static_cast<unsigned char>(singleCharacter));
}
- ALWAYS_INLINE JSString* jsStringWithCache(ExecState* exec, const AtomicString& s)
- {
- return jsStringWithCache(exec, s.string());
+ if (JSString* lastCachedString = vm.lastCachedString.get()) {
+ if (lastCachedString->tryGetValueImpl() == stringImpl)
+ return lastCachedString;
}
- ALWAYS_INLINE bool JSString::getStringPropertySlot(ExecState* exec, PropertyName propertyName, PropertySlot& slot)
- {
- if (propertyName == exec->propertyNames().length) {
- slot.setValue(this, DontEnum | DontDelete | ReadOnly, jsNumber(m_length));
- return true;
- }
+ return jsStringWithCacheSlowCase(vm, *stringImpl);
+}
- unsigned i = propertyName.asIndex();
- if (i < m_length) {
- ASSERT(i != PropertyName::NotAnIndex); // No need for an explicit check, the above test would always fail!
- slot.setValue(this, DontDelete | ReadOnly, getIndex(exec, i));
- return true;
- }
+ALWAYS_INLINE JSString* jsStringWithCache(ExecState* exec, const AtomicString& s)
+{
+ return jsStringWithCache(exec, s.string());
+}
- return false;
+ALWAYS_INLINE bool JSString::getStringPropertySlot(ExecState* exec, PropertyName propertyName, PropertySlot& slot)
+{
+ if (propertyName == exec->propertyNames().length) {
+ slot.setValue(this, DontEnum | DontDelete | ReadOnly, jsNumber(m_length));
+ return true;
}
-
- ALWAYS_INLINE bool JSString::getStringPropertySlot(ExecState* exec, unsigned propertyName, PropertySlot& slot)
- {
- if (propertyName < m_length) {
- slot.setValue(this, DontDelete | ReadOnly, getIndex(exec, propertyName));
- return true;
- }
- return false;
+ Optional<uint32_t> index = parseIndex(propertyName);
+ if (index && index.value() < m_length) {
+ slot.setValue(this, DontDelete | ReadOnly, getIndex(exec, index.value()));
+ return true;
}
- inline bool isJSString(JSValue v) { return v.isCell() && v.asCell()->type() == StringType; }
-
- // --- JSValue inlines ----------------------------
-
- inline bool JSValue::toBoolean(ExecState* exec) const
- {
- if (isInt32())
- return asInt32();
- if (isDouble())
- return asDouble() > 0.0 || asDouble() < 0.0; // false for NaN
- if (isCell())
- return asCell()->toBoolean(exec);
- return isTrue(); // false, null, and undefined all convert to false.
- }
+ return false;
+}
- inline JSString* JSValue::toString(ExecState* exec) const
- {
- if (isString())
- return jsCast<JSString*>(asCell());
- return toStringSlowCase(exec);
+ALWAYS_INLINE bool JSString::getStringPropertySlot(ExecState* exec, unsigned propertyName, PropertySlot& slot)
+{
+ if (propertyName < m_length) {
+ slot.setValue(this, DontDelete | ReadOnly, getIndex(exec, propertyName));
+ return true;
}
- inline String JSValue::toWTFString(ExecState* exec) const
- {
- if (isString())
- return static_cast<JSString*>(asCell())->value(exec);
- return toWTFStringSlowCase(exec);
- }
+ return false;
+}
- ALWAYS_INLINE String inlineJSValueNotStringtoString(const JSValue& value, ExecState* exec)
- {
- VM& vm = exec->vm();
- if (value.isInt32())
- return vm.numericStrings.add(value.asInt32());
- if (value.isDouble())
- return vm.numericStrings.add(value.asDouble());
- if (value.isTrue())
- return vm.propertyNames->trueKeyword.string();
- if (value.isFalse())
- return vm.propertyNames->falseKeyword.string();
- if (value.isNull())
- return vm.propertyNames->nullKeyword.string();
- if (value.isUndefined())
- return vm.propertyNames->undefinedKeyword.string();
- return value.toString(exec)->value(exec);
- }
-
- ALWAYS_INLINE String JSValue::toWTFStringInline(ExecState* exec) const
- {
- if (isString())
- return static_cast<JSString*>(asCell())->value(exec);
+inline bool isJSString(JSValue v)
+{
+ return v.isCell() && v.asCell()->type() == StringType;
+}
- return inlineJSValueNotStringtoString(*this, exec);
+ALWAYS_INLINE StringView JSRopeString::unsafeView(ExecState& state) const
+{
+ if (isSubstring()) {
+ if (is8Bit())
+ return StringView(substringBase()->m_value.characters8() + substringOffset(), m_length);
+ return StringView(substringBase()->m_value.characters16() + substringOffset(), m_length);
+ }
+ resolveRope(&state);
+ return m_value;
+}
+
+ALWAYS_INLINE StringViewWithUnderlyingString JSRopeString::viewWithUnderlyingString(ExecState& state) const
+{
+ if (isSubstring()) {
+ auto& base = substringBase()->m_value;
+ if (is8Bit())
+ return { { base.characters8() + substringOffset(), m_length }, base };
+ return { { base.characters16() + substringOffset(), m_length }, base };
}
+ resolveRope(&state);
+ return { m_value, m_value };
+}
+
+ALWAYS_INLINE StringView JSString::unsafeView(ExecState& state) const
+{
+ if (isRope())
+ return static_cast<const JSRopeString*>(this)->unsafeView(state);
+ return m_value;
+}
+
+ALWAYS_INLINE StringViewWithUnderlyingString JSString::viewWithUnderlyingString(ExecState& state) const
+{
+ if (isRope())
+ return static_cast<const JSRopeString&>(*this).viewWithUnderlyingString(state);
+ return { m_value, m_value };
+}
+
+inline bool JSString::isSubstring() const
+{
+ return isRope() && static_cast<const JSRopeString*>(this)->isSubstring();
+}
+
+inline JSString::SafeView::SafeView()
+{
+}
+
+inline JSString::SafeView::SafeView(ExecState& state, const JSString& string)
+ : m_state(&state)
+ , m_string(&string)
+{
+}
+
+inline JSString::SafeView::operator StringView() const
+{
+ return m_string->unsafeView(*m_state);
+}
+
+inline StringView JSString::SafeView::get() const
+{
+ return *this;
+}
+
+ALWAYS_INLINE JSString::SafeView JSString::view(ExecState* exec) const
+{
+ return SafeView(*exec, *this);
+}
+
+// --- JSValue inlines ----------------------------
+
+inline bool JSValue::toBoolean(ExecState* exec) const
+{
+ if (isInt32())
+ return asInt32();
+ if (isDouble())
+ return asDouble() > 0.0 || asDouble() < 0.0; // false for NaN
+ if (isCell())
+ return asCell()->toBoolean(exec);
+ return isTrue(); // false, null, and undefined all convert to false.
+}
+
+inline JSString* JSValue::toString(ExecState* exec) const
+{
+ if (isString())
+ return jsCast<JSString*>(asCell());
+ return toStringSlowCase(exec);
+}
+
+inline String JSValue::toWTFString(ExecState* exec) const
+{
+ if (isString())
+ return static_cast<JSString*>(asCell())->value(exec);
+ return toWTFStringSlowCase(exec);
+}
} // namespace JSC
projects / apple / javascriptcore.git / blobdiff