Source/JavaScriptCore/runtime/CommonSlowPaths.h - WebKit - Git at Google

 /*
  * Copyright (C) 2011-2019 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 "CodeBlock.h"
 #include "CodeSpecializationKind.h"
 #include "DirectArguments.h"
 #include "ExceptionHelpers.h"
 #include "FunctionCodeBlock.h"
 #include "JSImmutableButterfly.h"
 #include "ScopedArguments.h"
 #include "SlowPathReturnType.h"
 #include "StackAlignment.h"
 #include "VMInlines.h"
 #include <wtf/StdLibExtras.h>

 namespace JSC {

 // The purpose of this namespace is to include slow paths that are shared
 // between the interpreter and baseline JIT. They are written to be agnostic
 // with respect to the slow-path calling convention, but they do rely on the
 // JS code being executed more-or-less directly from bytecode (so the call
 // frame layout is unmodified, making it potentially awkward to use these
 // from any optimizing JIT, like the DFG).

 namespace CommonSlowPaths {

 ALWAYS_INLINE int numberOfExtraSlots(int argumentCountIncludingThis)
 {
     int frameSize = argumentCountIncludingThis + CallFrame::headerSizeInRegisters;
     int alignedFrameSize = WTF::roundUpToMultipleOf(stackAlignmentRegisters(), frameSize);
     return alignedFrameSize - frameSize;
 }

 ALWAYS_INLINE int numberOfStackPaddingSlots(CodeBlock* codeBlock, int argumentCountIncludingThis)
 {
     if (argumentCountIncludingThis >= codeBlock->numParameters())
         return 0;
     int alignedFrameSize = WTF::roundUpToMultipleOf(stackAlignmentRegisters(), argumentCountIncludingThis + CallFrame::headerSizeInRegisters);
     int alignedFrameSizeForParameters = WTF::roundUpToMultipleOf(stackAlignmentRegisters(), codeBlock->numParameters() + CallFrame::headerSizeInRegisters);
     return alignedFrameSizeForParameters - alignedFrameSize;
 }

 ALWAYS_INLINE int numberOfStackPaddingSlotsWithExtraSlots(CodeBlock* codeBlock, int argumentCountIncludingThis)
 {
     if (argumentCountIncludingThis >= codeBlock->numParameters())
         return 0;
     return numberOfStackPaddingSlots(codeBlock, argumentCountIncludingThis) + numberOfExtraSlots(argumentCountIncludingThis);
 }

 ALWAYS_INLINE CodeBlock* codeBlockFromCallFrameCallee(CallFrame* callFrame, CodeSpecializationKind kind)
 {
     JSFunction* callee = jsCast<JSFunction*>(callFrame->jsCallee());
     ASSERT(!callee->isHostFunction());
     return callee->jsExecutable()->codeBlockFor(kind);
 }

 ALWAYS_INLINE int arityCheckFor(VM& vm, CallFrame* callFrame, CodeSpecializationKind kind)
 {
     CodeBlock* newCodeBlock = codeBlockFromCallFrameCallee(callFrame, kind);
     ASSERT(callFrame->argumentCountIncludingThis() < static_cast<unsigned>(newCodeBlock->numParameters()));
     int padding = numberOfStackPaddingSlotsWithExtraSlots(newCodeBlock, callFrame->argumentCountIncludingThis());

     Register* newStack = callFrame->registers() - WTF::roundUpToMultipleOf(stackAlignmentRegisters(), padding);

     if (UNLIKELY(!vm.ensureStackCapacityFor(newStack)))
         return -1;
     return padding;
 }

 inline bool opInByVal(JSGlobalObject* globalObject, JSValue baseVal, JSValue propName, ArrayProfile* arrayProfile = nullptr)
 {
     VM& vm = getVM(globalObject);
     auto scope = DECLARE_THROW_SCOPE(vm);
     if (!baseVal.isObject()) {
         throwException(globalObject, scope, createInvalidInParameterError(globalObject, baseVal));
         return false;
     }

     JSObject* baseObj = asObject(baseVal);
     if (arrayProfile)
         arrayProfile->observeStructure(baseObj->structure(vm));

     uint32_t i;
     if (propName.getUInt32(i)) {
         if (arrayProfile)
             arrayProfile->observeIndexedRead(vm, baseObj, i);
         RELEASE_AND_RETURN(scope, baseObj->hasProperty(globalObject, i));
     }

     auto property = propName.toPropertyKey(globalObject);
     RETURN_IF_EXCEPTION(scope, false);
     RELEASE_AND_RETURN(scope, baseObj->hasProperty(globalObject, property));
 }

 inline bool canAccessArgumentIndexQuickly(JSObject& object, uint32_t index)
 {
     switch (object.type()) {
     case DirectArgumentsType: {
         DirectArguments* directArguments = jsCast<DirectArguments*>(&object);
         if (directArguments->isMappedArgumentInDFG(index))
             return true;
         break;
     }
     case ScopedArgumentsType: {
         ScopedArguments* scopedArguments = jsCast<ScopedArguments*>(&object);
         if (scopedArguments->isMappedArgumentInDFG(index))
             return true;
         break;
     }
     default:
         break;
     }
     return false;
 }

 static ALWAYS_INLINE void putDirectWithReify(VM& vm, JSGlobalObject* globalObject, JSObject* baseObject, PropertyName propertyName, JSValue value, PutPropertySlot& slot, Structure** result = nullptr)
 {
     auto scope = DECLARE_THROW_SCOPE(vm);
     if (baseObject->inherits<JSFunction>(vm)) {
         jsCast<JSFunction*>(baseObject)->reifyLazyPropertyIfNeeded(vm, globalObject, propertyName);
         RETURN_IF_EXCEPTION(scope, void());
     }
     if (result)
         *result = baseObject->structure(vm);
     scope.release();
     baseObject->putDirect(vm, propertyName, value, slot);
 }

 static ALWAYS_INLINE void putDirectAccessorWithReify(VM& vm, JSGlobalObject* globalObject, JSObject* baseObject, PropertyName propertyName, GetterSetter* accessor, unsigned attribute)
 {
     auto scope = DECLARE_THROW_SCOPE(vm);
     if (baseObject->inherits<JSFunction>(vm)) {
         jsCast<JSFunction*>(baseObject)->reifyLazyPropertyIfNeeded(vm, globalObject, propertyName);
         RETURN_IF_EXCEPTION(scope, void());
     }
     scope.release();
     baseObject->putDirectAccessor(globalObject, propertyName, accessor, attribute);
 }

 inline JSArray* allocateNewArrayBuffer(VM& vm, Structure* structure, JSImmutableButterfly* immutableButterfly)
 {
     JSGlobalObject* globalObject = structure->globalObject();
     Structure* originalStructure = globalObject->originalArrayStructureForIndexingType(immutableButterfly->indexingMode());
     ASSERT(originalStructure->indexingMode() == immutableButterfly->indexingMode());
     ASSERT(isCopyOnWrite(immutableButterfly->indexingMode()));
     ASSERT(!structure->outOfLineCapacity());

     JSArray* result = JSArray::createWithButterfly(vm, nullptr, originalStructure, immutableButterfly->toButterfly());
     // FIXME: This works but it's slow. If we cared enough about the perf when having a bad time then we could fix it.
     if (UNLIKELY(originalStructure != structure)) {
         ASSERT(hasSlowPutArrayStorage(structure->indexingMode()));
         ASSERT(globalObject->isHavingABadTime());

         result->switchToSlowPutArrayStorage(vm);
         ASSERT(result->butterfly() != immutableButterfly->toButterfly());
         ASSERT(!result->butterfly()->arrayStorage()->m_sparseMap.get());
         ASSERT(result->structureID() == structure->id());
     }

     return result;
 }

 } // namespace CommonSlowPaths

 class CallFrame;
 struct Instruction;

 #define SLOW_PATH

 #define SLOW_PATH_DECL(name) \
 extern "C" SlowPathReturnType SLOW_PATH name(CallFrame* callFrame, const Instruction* pc)

 #define SLOW_PATH_HIDDEN_DECL(name) \
 SLOW_PATH_DECL(name) WTF_INTERNAL

 SLOW_PATH_HIDDEN_DECL(slow_path_call_arityCheck);
 SLOW_PATH_HIDDEN_DECL(slow_path_construct_arityCheck);
 SLOW_PATH_HIDDEN_DECL(slow_path_create_direct_arguments);
 SLOW_PATH_HIDDEN_DECL(slow_path_create_scoped_arguments);
 SLOW_PATH_HIDDEN_DECL(slow_path_create_cloned_arguments);
 SLOW_PATH_HIDDEN_DECL(slow_path_create_arguments_butterfly);
 SLOW_PATH_HIDDEN_DECL(slow_path_create_this);
 SLOW_PATH_HIDDEN_DECL(slow_path_enter);
 SLOW_PATH_HIDDEN_DECL(slow_path_get_callee);
 SLOW_PATH_HIDDEN_DECL(slow_path_to_this);
 SLOW_PATH_HIDDEN_DECL(slow_path_throw_tdz_error);
 SLOW_PATH_HIDDEN_DECL(slow_path_check_tdz);
 SLOW_PATH_HIDDEN_DECL(slow_path_throw_strict_mode_readonly_property_write_error);
 SLOW_PATH_HIDDEN_DECL(slow_path_not);
 SLOW_PATH_HIDDEN_DECL(slow_path_eq);
 SLOW_PATH_HIDDEN_DECL(slow_path_neq);
 SLOW_PATH_HIDDEN_DECL(slow_path_stricteq);
 SLOW_PATH_HIDDEN_DECL(slow_path_nstricteq);
 SLOW_PATH_HIDDEN_DECL(slow_path_less);
 SLOW_PATH_HIDDEN_DECL(slow_path_lesseq);
 SLOW_PATH_HIDDEN_DECL(slow_path_greater);
 SLOW_PATH_HIDDEN_DECL(slow_path_greatereq);
 SLOW_PATH_HIDDEN_DECL(slow_path_inc);
 SLOW_PATH_HIDDEN_DECL(slow_path_dec);
 SLOW_PATH_HIDDEN_DECL(slow_path_to_number);
 SLOW_PATH_HIDDEN_DECL(slow_path_to_numeric);
 SLOW_PATH_HIDDEN_DECL(slow_path_to_string);
 SLOW_PATH_HIDDEN_DECL(slow_path_to_object);
 SLOW_PATH_HIDDEN_DECL(slow_path_negate);
 SLOW_PATH_HIDDEN_DECL(slow_path_add);
 SLOW_PATH_HIDDEN_DECL(slow_path_mul);
 SLOW_PATH_HIDDEN_DECL(slow_path_sub);
 SLOW_PATH_HIDDEN_DECL(slow_path_div);
 SLOW_PATH_HIDDEN_DECL(slow_path_mod);
 SLOW_PATH_HIDDEN_DECL(slow_path_pow);
 SLOW_PATH_HIDDEN_DECL(slow_path_lshift);
 SLOW_PATH_HIDDEN_DECL(slow_path_rshift);
 SLOW_PATH_HIDDEN_DECL(slow_path_urshift);
 SLOW_PATH_HIDDEN_DECL(slow_path_unsigned);
 SLOW_PATH_HIDDEN_DECL(slow_path_bitnot);
 SLOW_PATH_HIDDEN_DECL(slow_path_bitand);
 SLOW_PATH_HIDDEN_DECL(slow_path_bitor);
 SLOW_PATH_HIDDEN_DECL(slow_path_bitxor);
 SLOW_PATH_HIDDEN_DECL(slow_path_typeof);
 SLOW_PATH_HIDDEN_DECL(slow_path_is_object);
 SLOW_PATH_HIDDEN_DECL(slow_path_is_object_or_null);
 SLOW_PATH_HIDDEN_DECL(slow_path_is_function);
 SLOW_PATH_HIDDEN_DECL(slow_path_in_by_id);
 SLOW_PATH_HIDDEN_DECL(slow_path_in_by_val);
 SLOW_PATH_HIDDEN_DECL(slow_path_del_by_val);
 SLOW_PATH_HIDDEN_DECL(slow_path_strcat);
 SLOW_PATH_HIDDEN_DECL(slow_path_to_primitive);
 SLOW_PATH_HIDDEN_DECL(slow_path_to_property_key);
 SLOW_PATH_HIDDEN_DECL(slow_path_get_enumerable_length);
 SLOW_PATH_HIDDEN_DECL(slow_path_has_generic_property);
 SLOW_PATH_HIDDEN_DECL(slow_path_has_structure_property);
 SLOW_PATH_HIDDEN_DECL(slow_path_has_indexed_property);
 SLOW_PATH_HIDDEN_DECL(slow_path_get_direct_pname);
 SLOW_PATH_HIDDEN_DECL(slow_path_get_property_enumerator);
 SLOW_PATH_HIDDEN_DECL(slow_path_enumerator_structure_pname);
 SLOW_PATH_HIDDEN_DECL(slow_path_enumerator_generic_pname);
 SLOW_PATH_HIDDEN_DECL(slow_path_to_index_string);
 SLOW_PATH_HIDDEN_DECL(slow_path_profile_type_clear_log);
 SLOW_PATH_HIDDEN_DECL(slow_path_unreachable);
 SLOW_PATH_HIDDEN_DECL(slow_path_create_lexical_environment);
 SLOW_PATH_HIDDEN_DECL(slow_path_push_with_scope);
 SLOW_PATH_HIDDEN_DECL(slow_path_resolve_scope);
 SLOW_PATH_HIDDEN_DECL(slow_path_is_var_scope);
 SLOW_PATH_HIDDEN_DECL(slow_path_resolve_scope_for_hoisting_func_decl_in_eval);
 SLOW_PATH_HIDDEN_DECL(slow_path_create_promise);
 SLOW_PATH_HIDDEN_DECL(slow_path_create_generator);
 SLOW_PATH_HIDDEN_DECL(slow_path_create_async_generator);
 SLOW_PATH_HIDDEN_DECL(slow_path_create_rest);
 SLOW_PATH_HIDDEN_DECL(slow_path_get_by_id_with_this);
 SLOW_PATH_HIDDEN_DECL(slow_path_get_by_val_with_this);
 SLOW_PATH_HIDDEN_DECL(slow_path_put_by_id_with_this);
 SLOW_PATH_HIDDEN_DECL(slow_path_put_by_val_with_this);
 SLOW_PATH_HIDDEN_DECL(slow_path_define_data_property);
 SLOW_PATH_HIDDEN_DECL(slow_path_define_accessor_property);
 SLOW_PATH_HIDDEN_DECL(slow_path_throw_static_error);
 SLOW_PATH_HIDDEN_DECL(slow_path_new_promise);
 SLOW_PATH_HIDDEN_DECL(slow_path_new_generator);
 SLOW_PATH_HIDDEN_DECL(slow_path_new_array_with_spread);
 SLOW_PATH_HIDDEN_DECL(slow_path_new_array_buffer);
 SLOW_PATH_HIDDEN_DECL(slow_path_spread);

 using SlowPathFunction = SlowPathReturnType(SLOW_PATH *)(CallFrame*, const Instruction*);

 } // namespace JSC
	/*
	* Copyright (C) 2011-2019 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 "CodeBlock.h"
	#include "CodeSpecializationKind.h"
	#include "DirectArguments.h"
	#include "ExceptionHelpers.h"
	#include "FunctionCodeBlock.h"
	#include "JSImmutableButterfly.h"
	#include "ScopedArguments.h"
	#include "SlowPathReturnType.h"
	#include "StackAlignment.h"
	#include "VMInlines.h"
	#include <wtf/StdLibExtras.h>

	namespace JSC {

	// The purpose of this namespace is to include slow paths that are shared
	// between the interpreter and baseline JIT. They are written to be agnostic
	// with respect to the slow-path calling convention, but they do rely on the
	// JS code being executed more-or-less directly from bytecode (so the call
	// frame layout is unmodified, making it potentially awkward to use these
	// from any optimizing JIT, like the DFG).

	namespace CommonSlowPaths {

	ALWAYS_INLINE int numberOfExtraSlots(int argumentCountIncludingThis)
	{
	int frameSize = argumentCountIncludingThis + CallFrame::headerSizeInRegisters;
	int alignedFrameSize = WTF::roundUpToMultipleOf(stackAlignmentRegisters(), frameSize);
	return alignedFrameSize - frameSize;
	}

	ALWAYS_INLINE int numberOfStackPaddingSlots(CodeBlock* codeBlock, int argumentCountIncludingThis)
	{
	if (argumentCountIncludingThis >= codeBlock->numParameters())
	return 0;
	int alignedFrameSize = WTF::roundUpToMultipleOf(stackAlignmentRegisters(), argumentCountIncludingThis + CallFrame::headerSizeInRegisters);
	int alignedFrameSizeForParameters = WTF::roundUpToMultipleOf(stackAlignmentRegisters(), codeBlock->numParameters() + CallFrame::headerSizeInRegisters);
	return alignedFrameSizeForParameters - alignedFrameSize;
	}

	ALWAYS_INLINE int numberOfStackPaddingSlotsWithExtraSlots(CodeBlock* codeBlock, int argumentCountIncludingThis)
	{
	if (argumentCountIncludingThis >= codeBlock->numParameters())
	return 0;
	return numberOfStackPaddingSlots(codeBlock, argumentCountIncludingThis) + numberOfExtraSlots(argumentCountIncludingThis);
	}

	ALWAYS_INLINE CodeBlock* codeBlockFromCallFrameCallee(CallFrame* callFrame, CodeSpecializationKind kind)
	{
	JSFunction* callee = jsCast<JSFunction*>(callFrame->jsCallee());
	ASSERT(!callee->isHostFunction());
	return callee->jsExecutable()->codeBlockFor(kind);
	}

	ALWAYS_INLINE int arityCheckFor(VM& vm, CallFrame* callFrame, CodeSpecializationKind kind)
	{
	CodeBlock* newCodeBlock = codeBlockFromCallFrameCallee(callFrame, kind);
	ASSERT(callFrame->argumentCountIncludingThis() < static_cast<unsigned>(newCodeBlock->numParameters()));
	int padding = numberOfStackPaddingSlotsWithExtraSlots(newCodeBlock, callFrame->argumentCountIncludingThis());

	Register* newStack = callFrame->registers() - WTF::roundUpToMultipleOf(stackAlignmentRegisters(), padding);

	if (UNLIKELY(!vm.ensureStackCapacityFor(newStack)))
	return -1;
	return padding;
	}

	inline bool opInByVal(JSGlobalObject* globalObject, JSValue baseVal, JSValue propName, ArrayProfile* arrayProfile = nullptr)
	{
	VM& vm = getVM(globalObject);
	auto scope = DECLARE_THROW_SCOPE(vm);
	if (!baseVal.isObject()) {
	throwException(globalObject, scope, createInvalidInParameterError(globalObject, baseVal));
	return false;
	}

	JSObject* baseObj = asObject(baseVal);
	if (arrayProfile)
	arrayProfile->observeStructure(baseObj->structure(vm));

	uint32_t i;
	if (propName.getUInt32(i)) {
	if (arrayProfile)
	arrayProfile->observeIndexedRead(vm, baseObj, i);
	RELEASE_AND_RETURN(scope, baseObj->hasProperty(globalObject, i));
	}

	auto property = propName.toPropertyKey(globalObject);
	RETURN_IF_EXCEPTION(scope, false);
	RELEASE_AND_RETURN(scope, baseObj->hasProperty(globalObject, property));
	}

	inline bool canAccessArgumentIndexQuickly(JSObject& object, uint32_t index)
	{
	switch (object.type()) {
	case DirectArgumentsType: {
	DirectArguments* directArguments = jsCast<DirectArguments*>(&object);
	if (directArguments->isMappedArgumentInDFG(index))
	return true;
	break;
	}
	case ScopedArgumentsType: {
	ScopedArguments* scopedArguments = jsCast<ScopedArguments*>(&object);
	if (scopedArguments->isMappedArgumentInDFG(index))
	return true;
	break;
	}
	default:
	break;
	}
	return false;
	}

	static ALWAYS_INLINE void putDirectWithReify(VM& vm, JSGlobalObject* globalObject, JSObject* baseObject, PropertyName propertyName, JSValue value, PutPropertySlot& slot, Structure** result = nullptr)
	{
	auto scope = DECLARE_THROW_SCOPE(vm);
	if (baseObject->inherits<JSFunction>(vm)) {
	jsCast<JSFunction*>(baseObject)->reifyLazyPropertyIfNeeded(vm, globalObject, propertyName);
	RETURN_IF_EXCEPTION(scope, void());
	}
	if (result)
	*result = baseObject->structure(vm);
	scope.release();
	baseObject->putDirect(vm, propertyName, value, slot);
	}

	static ALWAYS_INLINE void putDirectAccessorWithReify(VM& vm, JSGlobalObject* globalObject, JSObject* baseObject, PropertyName propertyName, GetterSetter* accessor, unsigned attribute)
	{
	auto scope = DECLARE_THROW_SCOPE(vm);
	if (baseObject->inherits<JSFunction>(vm)) {
	jsCast<JSFunction*>(baseObject)->reifyLazyPropertyIfNeeded(vm, globalObject, propertyName);
	RETURN_IF_EXCEPTION(scope, void());
	}
	scope.release();
	baseObject->putDirectAccessor(globalObject, propertyName, accessor, attribute);
	}

	inline JSArray* allocateNewArrayBuffer(VM& vm, Structure* structure, JSImmutableButterfly* immutableButterfly)
	{
	JSGlobalObject* globalObject = structure->globalObject();
	Structure* originalStructure = globalObject->originalArrayStructureForIndexingType(immutableButterfly->indexingMode());
	ASSERT(originalStructure->indexingMode() == immutableButterfly->indexingMode());
	ASSERT(isCopyOnWrite(immutableButterfly->indexingMode()));
	ASSERT(!structure->outOfLineCapacity());

	JSArray* result = JSArray::createWithButterfly(vm, nullptr, originalStructure, immutableButterfly->toButterfly());
	// FIXME: This works but it's slow. If we cared enough about the perf when having a bad time then we could fix it.
	if (UNLIKELY(originalStructure != structure)) {
	ASSERT(hasSlowPutArrayStorage(structure->indexingMode()));
	ASSERT(globalObject->isHavingABadTime());

	result->switchToSlowPutArrayStorage(vm);
	ASSERT(result->butterfly() != immutableButterfly->toButterfly());
	ASSERT(!result->butterfly()->arrayStorage()->m_sparseMap.get());
	ASSERT(result->structureID() == structure->id());
	}

	return result;
	}

	} // namespace CommonSlowPaths

	class CallFrame;
	struct Instruction;

	#define SLOW_PATH

	#define SLOW_PATH_DECL(name) \
	extern "C" SlowPathReturnType SLOW_PATH name(CallFrame* callFrame, const Instruction* pc)

	#define SLOW_PATH_HIDDEN_DECL(name) \
	SLOW_PATH_DECL(name) WTF_INTERNAL

	SLOW_PATH_HIDDEN_DECL(slow_path_call_arityCheck);
	SLOW_PATH_HIDDEN_DECL(slow_path_construct_arityCheck);
	SLOW_PATH_HIDDEN_DECL(slow_path_create_direct_arguments);
	SLOW_PATH_HIDDEN_DECL(slow_path_create_scoped_arguments);
	SLOW_PATH_HIDDEN_DECL(slow_path_create_cloned_arguments);
	SLOW_PATH_HIDDEN_DECL(slow_path_create_arguments_butterfly);
	SLOW_PATH_HIDDEN_DECL(slow_path_create_this);
	SLOW_PATH_HIDDEN_DECL(slow_path_enter);
	SLOW_PATH_HIDDEN_DECL(slow_path_get_callee);
	SLOW_PATH_HIDDEN_DECL(slow_path_to_this);
	SLOW_PATH_HIDDEN_DECL(slow_path_throw_tdz_error);
	SLOW_PATH_HIDDEN_DECL(slow_path_check_tdz);
	SLOW_PATH_HIDDEN_DECL(slow_path_throw_strict_mode_readonly_property_write_error);
	SLOW_PATH_HIDDEN_DECL(slow_path_not);
	SLOW_PATH_HIDDEN_DECL(slow_path_eq);
	SLOW_PATH_HIDDEN_DECL(slow_path_neq);
	SLOW_PATH_HIDDEN_DECL(slow_path_stricteq);
	SLOW_PATH_HIDDEN_DECL(slow_path_nstricteq);
	SLOW_PATH_HIDDEN_DECL(slow_path_less);
	SLOW_PATH_HIDDEN_DECL(slow_path_lesseq);
	SLOW_PATH_HIDDEN_DECL(slow_path_greater);
	SLOW_PATH_HIDDEN_DECL(slow_path_greatereq);
	SLOW_PATH_HIDDEN_DECL(slow_path_inc);
	SLOW_PATH_HIDDEN_DECL(slow_path_dec);
	SLOW_PATH_HIDDEN_DECL(slow_path_to_number);
	SLOW_PATH_HIDDEN_DECL(slow_path_to_numeric);
	SLOW_PATH_HIDDEN_DECL(slow_path_to_string);
	SLOW_PATH_HIDDEN_DECL(slow_path_to_object);
	SLOW_PATH_HIDDEN_DECL(slow_path_negate);
	SLOW_PATH_HIDDEN_DECL(slow_path_add);
	SLOW_PATH_HIDDEN_DECL(slow_path_mul);
	SLOW_PATH_HIDDEN_DECL(slow_path_sub);
	SLOW_PATH_HIDDEN_DECL(slow_path_div);
	SLOW_PATH_HIDDEN_DECL(slow_path_mod);
	SLOW_PATH_HIDDEN_DECL(slow_path_pow);
	SLOW_PATH_HIDDEN_DECL(slow_path_lshift);
	SLOW_PATH_HIDDEN_DECL(slow_path_rshift);
	SLOW_PATH_HIDDEN_DECL(slow_path_urshift);
	SLOW_PATH_HIDDEN_DECL(slow_path_unsigned);
	SLOW_PATH_HIDDEN_DECL(slow_path_bitnot);
	SLOW_PATH_HIDDEN_DECL(slow_path_bitand);
	SLOW_PATH_HIDDEN_DECL(slow_path_bitor);
	SLOW_PATH_HIDDEN_DECL(slow_path_bitxor);
	SLOW_PATH_HIDDEN_DECL(slow_path_typeof);
	SLOW_PATH_HIDDEN_DECL(slow_path_is_object);
	SLOW_PATH_HIDDEN_DECL(slow_path_is_object_or_null);
	SLOW_PATH_HIDDEN_DECL(slow_path_is_function);
	SLOW_PATH_HIDDEN_DECL(slow_path_in_by_id);
	SLOW_PATH_HIDDEN_DECL(slow_path_in_by_val);
	SLOW_PATH_HIDDEN_DECL(slow_path_del_by_val);
	SLOW_PATH_HIDDEN_DECL(slow_path_strcat);
	SLOW_PATH_HIDDEN_DECL(slow_path_to_primitive);
	SLOW_PATH_HIDDEN_DECL(slow_path_to_property_key);
	SLOW_PATH_HIDDEN_DECL(slow_path_get_enumerable_length);
	SLOW_PATH_HIDDEN_DECL(slow_path_has_generic_property);
	SLOW_PATH_HIDDEN_DECL(slow_path_has_structure_property);
	SLOW_PATH_HIDDEN_DECL(slow_path_has_indexed_property);
	SLOW_PATH_HIDDEN_DECL(slow_path_get_direct_pname);
	SLOW_PATH_HIDDEN_DECL(slow_path_get_property_enumerator);
	SLOW_PATH_HIDDEN_DECL(slow_path_enumerator_structure_pname);
	SLOW_PATH_HIDDEN_DECL(slow_path_enumerator_generic_pname);
	SLOW_PATH_HIDDEN_DECL(slow_path_to_index_string);
	SLOW_PATH_HIDDEN_DECL(slow_path_profile_type_clear_log);
	SLOW_PATH_HIDDEN_DECL(slow_path_unreachable);
	SLOW_PATH_HIDDEN_DECL(slow_path_create_lexical_environment);
	SLOW_PATH_HIDDEN_DECL(slow_path_push_with_scope);
	SLOW_PATH_HIDDEN_DECL(slow_path_resolve_scope);
	SLOW_PATH_HIDDEN_DECL(slow_path_is_var_scope);
	SLOW_PATH_HIDDEN_DECL(slow_path_resolve_scope_for_hoisting_func_decl_in_eval);
	SLOW_PATH_HIDDEN_DECL(slow_path_create_promise);
	SLOW_PATH_HIDDEN_DECL(slow_path_create_generator);
	SLOW_PATH_HIDDEN_DECL(slow_path_create_async_generator);
	SLOW_PATH_HIDDEN_DECL(slow_path_create_rest);
	SLOW_PATH_HIDDEN_DECL(slow_path_get_by_id_with_this);
	SLOW_PATH_HIDDEN_DECL(slow_path_get_by_val_with_this);
	SLOW_PATH_HIDDEN_DECL(slow_path_put_by_id_with_this);
	SLOW_PATH_HIDDEN_DECL(slow_path_put_by_val_with_this);
	SLOW_PATH_HIDDEN_DECL(slow_path_define_data_property);
	SLOW_PATH_HIDDEN_DECL(slow_path_define_accessor_property);
	SLOW_PATH_HIDDEN_DECL(slow_path_throw_static_error);
	SLOW_PATH_HIDDEN_DECL(slow_path_new_promise);
	SLOW_PATH_HIDDEN_DECL(slow_path_new_generator);
	SLOW_PATH_HIDDEN_DECL(slow_path_new_array_with_spread);
	SLOW_PATH_HIDDEN_DECL(slow_path_new_array_buffer);
	SLOW_PATH_HIDDEN_DECL(slow_path_spread);

	using SlowPathFunction = SlowPathReturnType(SLOW_PATH )(CallFrame, const Instruction*);

	} // namespace JSC