#import "config.h"

#import "JSScriptInternal.h"

#import "APICast.h"

#import "BytecodeCacheError.h"

#import "CachedTypes.h"

#import "CodeCache.h"

#import "Identifier.h"

#import "JSContextInternal.h"

#import "JSScriptSourceProvider.h"

#import "JSSourceCode.h"

#import "JSValuePrivate.h"

#import "JSVirtualMachineInternal.h"

#import "Symbol.h"

#import <sys/stat.h>

#import <wtf/FileSystem.h>

#import <wtf/SHA1.h>

#import <wtf/SafeStrerror.h>

#import <wtf/Scope.h>

#import <wtf/WeakObjCPtr.h>

#import <wtf/spi/darwin/DataVaultSPI.h>

#if JSC_OBJC_API_ENABLED

@implementation JSScript {

WeakObjCPtr<JSVirtualMachine> m_virtualMachine;

JSScriptType m_type;

FileSystem::MappedFileData m_mappedSource;

String m_source;

RetainPtr<NSURL> m_sourceURL;

RetainPtr<NSURL> m_cachePath;

RefPtr<JSC::CachedBytecode> m_cachedBytecode;

}

static JSScript *createError(NSString *message, NSError** error)

{

if (error)

*error = [NSError errorWithDomain:@"JSScriptErrorDomain" code:1 userInfo:@{ @"message": message }];

return nil;

}

static bool validateBytecodeCachePath(NSURL* cachePath, NSError** error)

{

if (!cachePath)

return true;

URL cachePathURL([cachePath absoluteURL]);

if (!cachePathURL.isLocalFile()) {

createError([NSString stringWithFormat:@"Cache path `%@` is not a local file", static_cast<NSURL *>(cachePathURL)], error);

return false;

}

String systemPath = cachePathURL.fileSystemPath();

if (auto fileType = FileSystem::fileType(systemPath)) {

if (*fileType != FileSystem::FileType::Regular) {

createError([NSString stringWithFormat:@"Cache path `%@` already exists and is not a file", static_cast<NSString *>(systemPath)], error);

return false;

}

}

String directory = FileSystem::parentPath(systemPath);

if (directory.isNull()) {

createError([NSString stringWithFormat:@"Cache path `%@` does not contain in a valid directory", static_cast<NSString *>(systemPath)], error);

return false;

}

if (FileSystem::fileType(directory) != FileSystem::FileType::Directory) {

createError([NSString stringWithFormat:@"Cache directory `%@` is not a directory or does not exist", static_cast<NSString *>(directory)], error);

return false;

}

#if USE(APPLE_INTERNAL_SDK)

if (rootless_check_datavault_flag(FileSystem::fileSystemRepresentation(directory).data(), nullptr)) {

createError([NSString stringWithFormat:@"Cache directory `%@` is not a data vault", static_cast<NSString *>(directory)], error);

return false;

}

#endif

return true;

}

+ (instancetype)scriptOfType:(JSScriptType)type withSource:(NSString *)source andSourceURL:(NSURL *)sourceURL andBytecodeCache:(NSURL *)cachePath inVirtualMachine:(JSVirtualMachine *)vm error:(out NSError **)error

{

if (!validateBytecodeCachePath(cachePath, error))

return nil;

auto result = adoptNS([[JSScript alloc] init]);

result->m_virtualMachine = vm;

result->m_type = type;

result->m_source = source;

result->m_sourceURL = sourceURL;

result->m_cachePath = cachePath;

[result readCache];

return result.autorelease();

}

+ (instancetype)scriptOfType:(JSScriptType)type memoryMappedFromASCIIFile:(NSURL *)filePath withSourceURL:(NSURL *)sourceURL andBytecodeCache:(NSURL *)cachePath inVirtualMachine:(JSVirtualMachine *)vm error:(out NSError **)error

{

if (!validateBytecodeCachePath(cachePath, error))

return nil;

URL filePathURL([filePath absoluteURL]);

if (!filePathURL.isLocalFile())

return createError([NSString stringWithFormat:@"File path %@ is not a local file", static_cast<NSURL *>(filePathURL)], error);

bool success = false;

String systemPath = filePathURL.fileSystemPath();

FileSystem::MappedFileData fileData(systemPath, FileSystem::MappedFileMode::Shared, success);

if (!success)

return createError([NSString stringWithFormat:@"File at path %@ could not be mapped.", static_cast<NSString *>(systemPath)], error);

if (!charactersAreAllASCII(reinterpret_cast<const LChar*>(fileData.data()), fileData.size()))

return createError([NSString stringWithFormat:@"Not all characters in file at %@ are ASCII.", static_cast<NSString *>(systemPath)], error);

auto result = adoptNS([[JSScript alloc] init]);

result->m_virtualMachine = vm;

result->m_type = type;

result->m_source = String(StringImpl::createWithoutCopying(bitwise_cast<const LChar*>(fileData.data()), fileData.size()));

result->m_mappedSource = WTFMove(fileData);

result->m_sourceURL = sourceURL;

result->m_cachePath = cachePath;

[result readCache];

return result.autorelease();

}

- (void)readCache

{

if (!m_cachePath)

return;

NSString *cachePathString = [m_cachePath path];

const char* cacheFilename = cachePathString.UTF8String;

auto fd = FileSystem::openAndLockFile(cacheFilename, FileSystem::FileOpenMode::Read, {FileSystem::FileLockMode::Exclusive, FileSystem::FileLockMode::Nonblocking});

if (!FileSystem::isHandleValid(fd))

return;

auto closeFD = makeScopeExit([&] {

FileSystem::unlockAndCloseFile(fd);

});

bool success;

FileSystem::MappedFileData mappedFile(fd, FileSystem::MappedFileMode::Private, success);

if (!success)

return;

const uint8_t* fileData = reinterpret_cast<const uint8_t*>(mappedFile.data());

unsigned fileTotalSize = mappedFile.size();

// Ensure we at least have a SHA1::Digest to read.

if (fileTotalSize < sizeof(SHA1::Digest)) {

FileSystem::deleteFile(cacheFilename);

return;

}

unsigned fileDataSize = fileTotalSize - sizeof(SHA1::Digest);

SHA1::Digest computedHash;

SHA1 sha1;

sha1.addBytes(fileData, fileDataSize);

sha1.computeHash(computedHash);

SHA1::Digest fileHash;

memcpy(&fileHash, fileData + fileDataSize, sizeof(SHA1::Digest));

if (computedHash != fileHash) {

FileSystem::deleteFile(cacheFilename);

return;

}

Ref<JSC::CachedBytecode> cachedBytecode = JSC::CachedBytecode::create(WTFMove(mappedFile));

JSC::VM& vm = *toJS([m_virtualMachine JSContextGroupRef]);

JSC::SourceCode sourceCode = [self sourceCode];

JSC::SourceCodeKey key = m_type == kJSScriptTypeProgram ? sourceCodeKeyForSerializedProgram(vm, sourceCode) : sourceCodeKeyForSerializedModule(vm, sourceCode);

if (isCachedBytecodeStillValid(vm, cachedBytecode.copyRef(), key, m_type == kJSScriptTypeProgram ? JSC::SourceCodeType::ProgramType : JSC::SourceCodeType::ModuleType))

m_cachedBytecode = WTFMove(cachedBytecode);

else

FileSystem::truncateFile(fd, 0);

}

- (BOOL)cacheBytecodeWithError:(NSError **)error

{

String errorString { };

[self writeCache:errorString];

if (!errorString.isNull()) {

createError(errorString, error);

return NO;

}

return YES;

}

- (BOOL)isUsingBytecodeCache

{

return !!m_cachedBytecode->size();

}

- (NSURL *)sourceURL

{

return m_sourceURL.get();

}

- (JSScriptType)type

{

return m_type;

}

@implementation JSScript(Internal)

- (instancetype)init

{

self = [super init];

if (!self)

return nil;

self->m_cachedBytecode = JSC::CachedBytecode::create();

return self;

}

- (unsigned)hash

{

return m_source.hash();

}

- (const String&)source

{

return m_source;

}

- (RefPtr<JSC::CachedBytecode>)cachedBytecode

{

return m_cachedBytecode;

}

- (JSC::SourceCode)sourceCode

{

JSC::VM& vm = *toJS([m_virtualMachine JSContextGroupRef]);

JSC::JSLockHolder locker(vm);

TextPosition startPosition { };

String filename = String { [[self sourceURL] absoluteString] };

URL url = URL({ }, filename);

auto type = m_type == kJSScriptTypeModule ? JSC::SourceProviderSourceType::Module : JSC::SourceProviderSourceType::Program;

JSC::SourceOrigin origin(url);

Ref<JSScriptSourceProvider> sourceProvider = JSScriptSourceProvider::create(self, origin, WTFMove(filename), startPosition, type);

JSC::SourceCode sourceCode(WTFMove(sourceProvider), startPosition.m_line.oneBasedInt(), startPosition.m_column.oneBasedInt());

return sourceCode;

}

- (JSC::JSSourceCode*)jsSourceCode

{

JSC::VM& vm = *toJS([m_virtualMachine JSContextGroupRef]);

JSC::JSLockHolder locker(vm);

JSC::JSSourceCode* jsSourceCode = JSC::JSSourceCode::create(vm, [self sourceCode]);

return jsSourceCode;

}

- (BOOL)writeCache:(String&)error

{

if (self.isUsingBytecodeCache) {

error = "Cache for JSScript is already non-empty. Can not override it."_s;

return NO;

}

if (!m_cachePath) {

error = "No cache path was provided during construction of this JSScript."_s;

return NO;

}

// We want to do the write as a transaction (i.e. we guarantee that it's all

// or nothing). So, we'll write to a temp file first, and rename the temp

// file to the cache file only after we've finished writing the whole thing.

NSString *cachePathString = [m_cachePath path];

const char* cacheFileName = cachePathString.UTF8String;

const char* tempFileName = [cachePathString stringByAppendingString:@".tmp"].UTF8String;

int fd = open(cacheFileName, O_CREAT | O_WRONLY | O_EXLOCK | O_NONBLOCK, 0600);

if (fd == -1) {

error = makeString("Could not open or lock the bytecode cache file. It's likely another VM or process is already using it. Error: ", safeStrerror(errno).data());

return NO;

}

auto closeFD = makeScopeExit([&] {

close(fd);

});

int tempFD = open(tempFileName, O_CREAT | O_RDWR | O_EXLOCK | O_NONBLOCK, 0600);

if (tempFD == -1) {

error = makeString("Could not open or lock the bytecode cache temp file. Error: ", safeStrerror(errno).data());

return NO;

}

auto closeTempFD = makeScopeExit([&] {

close(tempFD);

});

JSC::BytecodeCacheError cacheError;

JSC::SourceCode sourceCode = [self sourceCode];

JSC::VM& vm = *toJS([m_virtualMachine JSContextGroupRef]);

switch (m_type) {

case kJSScriptTypeModule:

m_cachedBytecode = JSC::generateModuleBytecode(vm, sourceCode, tempFD, cacheError);

break;

case kJSScriptTypeProgram:

m_cachedBytecode = JSC::generateProgramBytecode(vm, sourceCode, tempFD, cacheError);

break;

}

if (cacheError.isValid()) {

m_cachedBytecode = JSC::CachedBytecode::create();

FileSystem::truncateFile(fd, 0);

error = makeString("Unable to generate bytecode for this JSScript because: ", cacheError.message());

return NO;

}

SHA1::Digest computedHash;

SHA1 sha1;

sha1.addBytes(m_cachedBytecode->data(), m_cachedBytecode->size());

sha1.computeHash(computedHash);

FileSystem::writeToFile(tempFD, computedHash.data(), sizeof(computedHash));

fsync(tempFD);

rename(tempFileName, cacheFileName);

return YES;

}

#endif