#include "config.h"

#import "JavaScriptCore.h"

#if JSC_OBJC_API_ENABLED

#import "APICast.h"

#import "APIShims.h"

#import "JSAPIWrapperObject.h"

#import "JSCallbackObject.h"

#import "JSContextInternal.h"

#import "JSWrapperMap.h"

#import "ObjCCallbackFunction.h"

#import "ObjcRuntimeExtras.h"

#import "Operations.h"

#import "WeakGCMap.h"

#import <wtf/TCSpinLock.h>

#import <wtf/Vector.h>

#import <wtf/HashSet.h>

#include <mach-o/dyld.h>

static const int32_t webkitFirstVersionWithInitConstructorSupport = 0x21A0400; // 538.4.0

@class JSObjCClassInfo;

@interface JSWrapperMap ()

- (JSObjCClassInfo*)classInfoForClass:(Class)cls;

static NSString *selectorToPropertyName(const char* start)

{

// Use 'index' to check for colons, if there are none, this is easy!

const char* firstColon = index(start, ':');

if (!firstColon)

return [NSString stringWithUTF8String:start];

// 'header' is the length of string up to the first colon.

size_t header = firstColon - start;

// The new string needs to be long enough to hold 'header', plus the remainder of the string, excluding

// at least one ':', but including a '\0'. (This is conservative if there are more than one ':').

char* buffer = static_cast<char*>(malloc(header + strlen(firstColon + 1) + 1));

// Copy 'header' characters, set output to point to the end of this & input to point past the first ':'.

memcpy(buffer, start, header);

char* output = buffer + header;

const char* input = start + header + 1;

// On entry to the loop, we have already skipped over a ':' from the input.

while (true) {

char c;

// Skip over any additional ':'s. We'll leave c holding the next character after the

// last ':', and input pointing past c.

while ((c = *(input++)) == ':');

// Copy the character, converting to upper case if necessary.

// If the character we copy is '\0', then we're done!

if (!(*(output++) = toupper(c)))

goto done;

// Loop over characters other than ':'.

while ((c = *(input++)) != ':') {

// Copy the character.

// If the character we copy is '\0', then we're done!

if (!(*(output++) = c))

goto done;

}

// If we get here, we've consumed a ':' - wash, rinse, repeat.

}

done:

NSString *result = [NSString stringWithUTF8String:buffer];

free(buffer);

return result;

}

static JSObjectRef makeWrapper(JSContextRef ctx, JSClassRef jsClass, id wrappedObject)

{

JSC::ExecState* exec = toJS(ctx);

JSC::APIEntryShim entryShim(exec);

ASSERT(jsClass);

JSC::JSCallbackObject<JSC::JSAPIWrapperObject>* object = JSC::JSCallbackObject<JSC::JSAPIWrapperObject>::create(exec, exec->lexicalGlobalObject(), exec->lexicalGlobalObject()->objcWrapperObjectStructure(), jsClass, 0);

object->setWrappedObject(wrappedObject);

if (JSC::JSObject* prototype = jsClass->prototype(exec))

object->setPrototype(exec->vm(), prototype);

return toRef(object);

}

static JSValue *objectWithCustomBrand(JSContext *context, NSString *brand, Class cls = 0)

{

JSClassDefinition definition;

definition = kJSClassDefinitionEmpty;

definition.className = [brand UTF8String];

JSClassRef classRef = JSClassCreate(&definition);

JSObjectRef result = makeWrapper([context JSGlobalContextRef], classRef, cls);

JSClassRelease(classRef);

return [JSValue valueWithJSValueRef:result inContext:context];

}

static NSMutableDictionary *createRenameMap(Protocol *protocol, BOOL isInstanceMethod)

{

NSMutableDictionary *renameMap = [[NSMutableDictionary alloc] init];

forEachMethodInProtocol(protocol, NO, isInstanceMethod, ^(SEL sel, const char*){

NSString *rename = @(sel_getName(sel));

NSRange range = [rename rangeOfString:@"__JS_EXPORT_AS__"];

if (range.location == NSNotFound)

return;

NSString *selector = [rename substringToIndex:range.location];

NSUInteger begin = range.location + range.length;

NSUInteger length = [rename length] - begin - 1;

NSString *name = [rename substringWithRange:(NSRange){ begin, length }];

renameMap[selector] = name;

});

return renameMap;

}

inline void putNonEnumerable(JSValue *base, NSString *propertyName, JSValue *value)

{

[base defineProperty:propertyName descriptor:@{

JSPropertyDescriptorValueKey: value,

JSPropertyDescriptorWritableKey: @YES,

JSPropertyDescriptorEnumerableKey: @NO,

JSPropertyDescriptorConfigurableKey: @YES

}];

}

static bool isInitFamilyMethod(NSString *name)

{

NSUInteger i = 0;

// Skip over initial underscores.

for (; i < [name length]; ++i) {

if ([name characterAtIndex:i] != '_')

break;

}

// Match 'init'.

NSUInteger initIndex = 0;

NSString* init = @"init";

for (; i < [name length] && initIndex < [init length]; ++i, ++initIndex) {

if ([name characterAtIndex:i] != [init characterAtIndex:initIndex])

return false;

}

// We didn't match all of 'init'.

if (initIndex < [init length])

return false;

// If we're at the end or the next character is a capital letter then this is an init-family selector.

return i == [name length] || [[NSCharacterSet uppercaseLetterCharacterSet] characterIsMember:[name characterAtIndex:i]];

}

static bool shouldSkipMethodWithName(NSString *name)

{

// For clients that don't support init-based constructors just copy

// over the init method as we would have before.

if (!supportsInitMethodConstructors())

return false;

// Skip over init family methods because we handle those specially

// for the purposes of hooking up the constructor correctly.

return isInitFamilyMethod(name);

}

static void copyMethodsToObject(JSContext *context, Class objcClass, Protocol *protocol, BOOL isInstanceMethod, JSValue *object, NSMutableDictionary *accessorMethods = nil)

{

NSMutableDictionary *renameMap = createRenameMap(protocol, isInstanceMethod);

forEachMethodInProtocol(protocol, YES, isInstanceMethod, ^(SEL sel, const char* types){

const char* nameCStr = sel_getName(sel);

NSString *name = @(nameCStr);

if (shouldSkipMethodWithName(name))

return;

if (accessorMethods && accessorMethods[name]) {

JSObjectRef method = objCCallbackFunctionForMethod(context, objcClass, protocol, isInstanceMethod, sel, types);

if (!method)

return;

accessorMethods[name] = [JSValue valueWithJSValueRef:method inContext:context];

} else {

name = renameMap[name];

if (!name)

name = selectorToPropertyName(nameCStr);

if ([object hasProperty:name])

return;

JSObjectRef method = objCCallbackFunctionForMethod(context, objcClass, protocol, isInstanceMethod, sel, types);

if (method)

putNonEnumerable(object, name, [JSValue valueWithJSValueRef:method inContext:context]);

}

});

[renameMap release];

}

static bool parsePropertyAttributes(objc_property_t property, char*& getterName, char*& setterName)

{

bool readonly = false;

unsigned attributeCount;

objc_property_attribute_t* attributes = property_copyAttributeList(property, &attributeCount);

if (attributeCount) {

for (unsigned i = 0; i < attributeCount; ++i) {

switch (*(attributes[i].name)) {

case 'G':

getterName = strdup(attributes[i].value);

break;

case 'S':

setterName = strdup(attributes[i].value);

break;

case 'R':

readonly = true;

break;

default:

break;

}

}

free(attributes);

}

return readonly;

}

static char* makeSetterName(const char* name)

{

size_t nameLength = strlen(name);

char* setterName = (char*)malloc(nameLength + 5); // "set" Name ":\0"

setterName[0] = 's';

setterName[1] = 'e';

setterName[2] = 't';

setterName[3] = toupper(*name);

memcpy(setterName + 4, name + 1, nameLength - 1);

setterName[nameLength + 3] = ':';

setterName[nameLength + 4] = '\0';

return setterName;

}

static void copyPrototypeProperties(JSContext *context, Class objcClass, Protocol *protocol, JSValue *prototypeValue)

{

// First gather propreties into this list, then handle the methods (capturing the accessor methods).

struct Property {

const char* name;

char* getterName;

char* setterName;

};

__block Vector<Property> propertyList;

// Map recording the methods used as getters/setters.

NSMutableDictionary *accessorMethods = [NSMutableDictionary dictionary];

// Useful value.

JSValue *undefined = [JSValue valueWithUndefinedInContext:context];

forEachPropertyInProtocol(protocol, ^(objc_property_t property){

char* getterName = 0;

char* setterName = 0;

bool readonly = parsePropertyAttributes(property, getterName, setterName);

const char* name = property_getName(property);

// Add the names of the getter & setter methods to

if (!getterName)

getterName = strdup(name);

accessorMethods[@(getterName)] = undefined;

if (!readonly) {

if (!setterName)

setterName = makeSetterName(name);

accessorMethods[@(setterName)] = undefined;

}

// Add the properties to a list.

propertyList.append((Property){ name, getterName, setterName });

});

// Copy methods to the prototype, capturing accessors in the accessorMethods map.

copyMethodsToObject(context, objcClass, protocol, YES, prototypeValue, accessorMethods);

// Iterate the propertyList & generate accessor properties.

for (size_t i = 0; i < propertyList.size(); ++i) {

Property& property = propertyList[i];

JSValue *getter = accessorMethods[@(property.getterName)];

free(property.getterName);

ASSERT(![getter isUndefined]);

JSValue *setter = undefined;

if (property.setterName) {

setter = accessorMethods[@(property.setterName)];

free(property.setterName);

ASSERT(![setter isUndefined]);

}

[prototypeValue defineProperty:@(property.name) descriptor:@{

JSPropertyDescriptorGetKey: getter,

JSPropertyDescriptorSetKey: setter,

JSPropertyDescriptorEnumerableKey: @NO,

JSPropertyDescriptorConfigurableKey: @YES

}];

}

}

@interface JSObjCClassInfo : NSObject {

JSContext *m_context;

Class m_class;

bool m_block;

JSClassRef m_classRef;

JSC::Weak<JSC::JSObject> m_prototype;

JSC::Weak<JSC::JSObject> m_constructor;

}

- (id)initWithContext:(JSContext *)context forClass:(Class)cls superClassInfo:(JSObjCClassInfo*)superClassInfo;

- (JSValue *)wrapperForObject:(id)object;

- (JSValue *)constructor;

@implementation JSObjCClassInfo

- (id)initWithContext:(JSContext *)context forClass:(Class)cls superClassInfo:(JSObjCClassInfo*)superClassInfo

{

self = [super init];

if (!self)

return nil;

const char* className = class_getName(cls);

m_context = context;

m_class = cls;

m_block = [cls isSubclassOfClass:getNSBlockClass()];

JSClassDefinition definition;

definition = kJSClassDefinitionEmpty;

definition.className = className;

m_classRef = JSClassCreate(&definition);

[self allocateConstructorAndPrototypeWithSuperClassInfo:superClassInfo];

return self;

}

- (void)dealloc

{

JSClassRelease(m_classRef);

[super dealloc];

}

static JSValue *allocateConstructorForCustomClass(JSContext *context, const char* className, Class cls)

{

if (!supportsInitMethodConstructors())

return objectWithCustomBrand(context, [NSString stringWithFormat:@"%sConstructor", className], cls);

// For each protocol that the class implements, gather all of the init family methods into a hash table.

__block HashMap<String, Protocol *> initTable;

Protocol *exportProtocol = getJSExportProtocol();

for (Class currentClass = cls; currentClass; currentClass = class_getSuperclass(currentClass)) {

forEachProtocolImplementingProtocol(currentClass, exportProtocol, ^(Protocol *protocol) {

forEachMethodInProtocol(protocol, YES, YES, ^(SEL selector, const char*) {

const char* name = sel_getName(selector);

if (!isInitFamilyMethod(@(name)))

return;

initTable.set(name, protocol);

});

});

}

for (Class currentClass = cls; currentClass; currentClass = class_getSuperclass(currentClass)) {

__block unsigned numberOfInitsFound = 0;

__block SEL initMethod = 0;

__block Protocol *initProtocol = 0;

__block const char* types = 0;

forEachMethodInClass(currentClass, ^(Method method) {

SEL selector = method_getName(method);

const char* name = sel_getName(selector);

auto iter = initTable.find(name);

if (iter == initTable.end())

return;

numberOfInitsFound++;

initMethod = selector;

initProtocol = iter->value;

types = method_getTypeEncoding(method);

});

if (!numberOfInitsFound)

continue;

if (numberOfInitsFound > 1) {

NSLog(@"ERROR: Class %@ exported more than one init family method via JSExport. Class %@ will not have a callable JavaScript constructor function.", cls, cls);

break;

}

JSObjectRef method = objCCallbackFunctionForInit(context, cls, initProtocol, initMethod, types);

return [JSValue valueWithJSValueRef:method inContext:context];

}

return objectWithCustomBrand(context, [NSString stringWithFormat:@"%sConstructor", className], cls);

}

- (void)allocateConstructorAndPrototypeWithSuperClassInfo:(JSObjCClassInfo*)superClassInfo

{

ASSERT(!m_constructor || !m_prototype);

ASSERT((m_class == [NSObject class]) == !superClassInfo);

if (!superClassInfo) {

JSContextRef cContext = [m_context JSGlobalContextRef];

JSValue *constructor = m_context[@"Object"];

if (!m_constructor)

m_constructor = toJS(JSValueToObject(cContext, valueInternalValue(constructor), 0));

if (!m_prototype) {

JSValue *prototype = constructor[@"prototype"];

m_prototype = toJS(JSValueToObject(cContext, valueInternalValue(prototype), 0));

}

} else {

const char* className = class_getName(m_class);

// Create or grab the prototype/constructor pair.

JSValue *prototype;

JSValue *constructor;

if (m_prototype)

prototype = [JSValue valueWithJSValueRef:toRef(m_prototype.get()) inContext:m_context];

else

prototype = objectWithCustomBrand(m_context, [NSString stringWithFormat:@"%sPrototype", className]);

if (m_constructor)

constructor = [JSValue valueWithJSValueRef:toRef(m_constructor.get()) inContext:m_context];

else

constructor = allocateConstructorForCustomClass(m_context, className, m_class);

JSContextRef cContext = [m_context JSGlobalContextRef];

m_prototype = toJS(JSValueToObject(cContext, valueInternalValue(prototype), 0));

m_constructor = toJS(JSValueToObject(cContext, valueInternalValue(constructor), 0));

putNonEnumerable(prototype, @"constructor", constructor);

putNonEnumerable(constructor, @"prototype", prototype);

Protocol *exportProtocol = getJSExportProtocol();

forEachProtocolImplementingProtocol(m_class, exportProtocol, ^(Protocol *protocol){

copyPrototypeProperties(m_context, m_class, protocol, prototype);

copyMethodsToObject(m_context, m_class, protocol, NO, constructor);

});

// Set [Prototype].

JSObjectSetPrototype([m_context JSGlobalContextRef], toRef(m_prototype.get()), toRef(superClassInfo->m_prototype.get()));

}

}

- (void)reallocateConstructorAndOrPrototype

{

[self allocateConstructorAndPrototypeWithSuperClassInfo:[m_context.wrapperMap classInfoForClass:class_getSuperclass(m_class)]];

}

- (JSValue *)wrapperForObject:(id)object

{

ASSERT([object isKindOfClass:m_class]);

ASSERT(m_block == [object isKindOfClass:getNSBlockClass()]);

if (m_block) {

if (JSObjectRef method = objCCallbackFunctionForBlock(m_context, object)) {

JSValue *constructor = [JSValue valueWithJSValueRef:method inContext:m_context];

JSValue *prototype = [JSValue valueWithNewObjectInContext:m_context];

putNonEnumerable(constructor, @"prototype", prototype);

putNonEnumerable(prototype, @"constructor", constructor);

return constructor;

}

}

if (!m_prototype)

[self reallocateConstructorAndOrPrototype];

ASSERT(!!m_prototype);

JSObjectRef wrapper = makeWrapper([m_context JSGlobalContextRef], m_classRef, object);

JSObjectSetPrototype([m_context JSGlobalContextRef], wrapper, toRef(m_prototype.get()));

return [JSValue valueWithJSValueRef:wrapper inContext:m_context];

}

- (JSValue *)constructor

{

if (!m_constructor)

[self reallocateConstructorAndOrPrototype];

ASSERT(!!m_constructor);

return [JSValue valueWithJSValueRef:toRef(m_constructor.get()) inContext:m_context];

}

@implementation JSWrapperMap {

JSContext *m_context;

NSMutableDictionary *m_classMap;

JSC::WeakGCMap<id, JSC::JSObject> m_cachedJSWrappers;

NSMapTable *m_cachedObjCWrappers;

}

- (id)initWithContext:(JSContext *)context

{

self = [super init];

if (!self)

return nil;

NSPointerFunctionsOptions keyOptions = NSPointerFunctionsOpaqueMemory | NSPointerFunctionsOpaquePersonality;

NSPointerFunctionsOptions valueOptions = NSPointerFunctionsWeakMemory | NSPointerFunctionsObjectPersonality;

m_cachedObjCWrappers = [[NSMapTable alloc] initWithKeyOptions:keyOptions valueOptions:valueOptions capacity:0];

m_context = context;

m_classMap = [[NSMutableDictionary alloc] init];

return self;

}

- (void)dealloc

{

[m_cachedObjCWrappers release];

[m_classMap release];

[super dealloc];

}

- (JSObjCClassInfo*)classInfoForClass:(Class)cls

{

if (!cls)

return nil;

// Check if we've already created a JSObjCClassInfo for this Class.

if (JSObjCClassInfo* classInfo = (JSObjCClassInfo*)m_classMap[cls])

return classInfo;

// Skip internal classes beginning with '_' - just copy link to the parent class's info.

if ('_' == *class_getName(cls))

return m_classMap[cls] = [self classInfoForClass:class_getSuperclass(cls)];

return m_classMap[cls] = [[[JSObjCClassInfo alloc] initWithContext:m_context forClass:cls superClassInfo:[self classInfoForClass:class_getSuperclass(cls)]] autorelease];

}

- (JSValue *)jsWrapperForObject:(id)object

{

JSC::JSObject* jsWrapper = m_cachedJSWrappers.get(object);

if (jsWrapper)

return [JSValue valueWithJSValueRef:toRef(jsWrapper) inContext:m_context];

JSValue *wrapper;

if (class_isMetaClass(object_getClass(object)))

wrapper = [[self classInfoForClass:(Class)object] constructor];

else {

JSObjCClassInfo* classInfo = [self classInfoForClass:[object class]];

wrapper = [classInfo wrapperForObject:object];

}

// FIXME: https://bugs.webkit.org/show_bug.cgi?id=105891

// This general approach to wrapper caching is pretty effective, but there are a couple of problems:

// (1) For immortal objects JSValues will effectively leak and this results in error output being logged - we should avoid adding associated objects to immortal objects.

// (2) A long lived object may rack up many JSValues. When the contexts are released these will unprotect the associated JavaScript objects,

// but still, would probably nicer if we made it so that only one associated object was required, broadcasting object dealloc.

JSC::ExecState* exec = toJS([m_context JSGlobalContextRef]);

jsWrapper = toJS(exec, valueInternalValue(wrapper)).toObject(exec);

m_cachedJSWrappers.set(object, jsWrapper);

return wrapper;

}

- (JSValue *)objcWrapperForJSValueRef:(JSValueRef)value

{

JSValue *wrapper = static_cast<JSValue *>(NSMapGet(m_cachedObjCWrappers, value));

if (!wrapper) {

wrapper = [[[JSValue alloc] initWithValue:value inContext:m_context] autorelease];

NSMapInsert(m_cachedObjCWrappers, value, wrapper);

}

return wrapper;

}

id tryUnwrapObjcObject(JSGlobalContextRef context, JSValueRef value)

{

if (!JSValueIsObject(context, value))

return nil;

JSValueRef exception = 0;

JSObjectRef object = JSValueToObject(context, value, &exception);

ASSERT(!exception);

if (toJS(object)->inherits(JSC::JSCallbackObject<JSC::JSAPIWrapperObject>::info()))

return (id)JSC::jsCast<JSC::JSAPIWrapperObject*>(toJS(object))->wrappedObject();

if (id target = tryUnwrapConstructor(object))

return target;

return nil;

}

NS_ROOT_CLASS @interface JSExport <JSExport>

@implementation JSExport

bool supportsInitMethodConstructors()

{

static int32_t versionOfLinkTimeLibrary = 0;

if (!versionOfLinkTimeLibrary)

versionOfLinkTimeLibrary = NSVersionOfLinkTimeLibrary("JavaScriptCore");

return versionOfLinkTimeLibrary >= webkitFirstVersionWithInitConstructorSupport;

}

Protocol *getJSExportProtocol()

{

static Protocol *protocol = objc_getProtocol("JSExport");

return protocol;

}

Class getNSBlockClass()

{

static Class cls = objc_getClass("NSBlock");

return cls;

}

#endif