+ 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));
+}
+
+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));
+ }
projects / apple / javascriptcore.git / blobdiff