[wasm] Port FileManager for WASI platform

CoreFoundation/Base.subproj/ForSwiftFoundationOnly.h

@@ -45,7 +45,7 @@
 #if _POSIX_THREADS
 #include <pthread.h>
 #endif
-#if defined(__unix__) || (defined(__APPLE__) && defined(__MACH__))
+#if defined(__unix__) || (defined(__APPLE__) && defined(__MACH__)) || defined(__wasi__)
 #include <dirent.h>
 #endif
 
@@ -565,11 +565,11 @@ CF_CROSS_PLATFORM_EXPORT int _CFOpenFileWithMode(const char *path, int opts, mod
 CF_CROSS_PLATFORM_EXPORT void *_CFReallocf(void *ptr, size_t size);
 CF_CROSS_PLATFORM_EXPORT int _CFOpenFile(const char *path, int opts);
 
-#if defined(__unix__) || (defined(__APPLE__) && defined(__MACH__))
+#if defined(__unix__) || (defined(__APPLE__) && defined(__MACH__)) || defined(__wasi__)
 static inline int _direntNameLength(struct dirent *entry) {
 #ifdef _D_EXACT_NAMLEN // defined on Linux
  return _D_EXACT_NAMLEN(entry);
-#elif TARGET_OS_LINUX || TARGET_OS_ANDROID
+#elif TARGET_OS_LINUX || TARGET_OS_ANDROID || TARGET_OS_WASI
  return strlen(entry->d_name);
 #else
  return entry->d_namlen;
@@ -578,11 +578,21 @@ static inline int _direntNameLength(struct dirent *entry) {
 
 // major() and minor() might be implemented as macros or functions.
 static inline unsigned int _dev_major(dev_t rdev) {
+#if !TARGET_OS_WASI
  return major(rdev);
+#else
+ // WASI does not have device numbers
+ return 0;
+#endif
 }
 
 static inline unsigned int _dev_minor(dev_t rdev) {
+#if !TARGET_OS_WASI
  return minor(rdev);
+#else
+ // WASI does not have device numbers
+ return 0;
+#endif
 }
 
 #endif

Sources/Foundation/FileHandle.swift

@@ -27,6 +27,12 @@ import Musl
 fileprivate let _read = Musl.read(_:_:_:)
 fileprivate let _write = Musl.write(_:_:_:)
 fileprivate let _close = Musl.close(_:)
+#elseif canImport(WASILibc)
+import WASILibc
+@_implementationOnly import wasi_emulated_mman
+fileprivate let _read = WASILibc.read(_:_:_:)
+fileprivate let _write = WASILibc.write(_:_:_:)
+fileprivate let _close = WASILibc.close(_:)
 #endif
 
 #if canImport(WinSDK)

Sources/Foundation/FileManager+POSIX.swift

@@ -96,6 +96,32 @@ extension FileManager {
  return nil
  }
  urls = mountPoints(statBuf, Int(fsCount))
+#elseif os(WASI)
+ // Skip the first three file descriptors, which are reserved for stdin, stdout, and stderr.
+ var fd: __wasi_fd_t = 3
+ let __WASI_PREOPENTYPE_DIR: UInt8 = 0
+ while true {
+ var prestat = __wasi_prestat_t()
+ guard __wasi_fd_prestat_get(fd, &prestat) == 0 else {
+ break
+ }
+
+ if prestat.tag == __WASI_PREOPENTYPE_DIR {
+ var buf = [UInt8](repeating: 0, count: Int(prestat.u.dir.pr_name_len))
+ guard __wasi_fd_prestat_dir_name(fd, &buf, prestat.u.dir.pr_name_len) == 0 else {
+ break
+ }
+ let path = buf.withUnsafeBufferPointer { buf in
+ guard let baseAddress = buf.baseAddress else {
+ return ""
+ }
+ let base = UnsafeRawPointer(baseAddress).assumingMemoryBound(to: Int8.self)
+ return string(withFileSystemRepresentation: base, length: buf.count)
+ }
+ urls.append(URL(fileURLWithPath: path, isDirectory: true))
+ }
+ fd += 1
+ }
 #else
 #error("Requires a platform-specific implementation")
 #endif
@@ -446,6 +472,10 @@ extension FileManager {
  }
 
  internal func _attributesOfFileSystemIncludingBlockSize(forPath path: String) throws -> (attributes: [FileAttributeKey : Any], blockSize: UInt64?) {
+ #if os(WASI)
+ // WASI doesn't have statvfs
+ throw _NSErrorWithErrno(ENOTSUP, reading: true, path: path)
+ #else
  var result: [FileAttributeKey:Any] = [:]
  var finalBlockSize: UInt64?
 
@@ -478,6 +508,7 @@ extension FileManager {
  finalBlockSize = blockSize
  }
  return (attributes: result, blockSize: finalBlockSize)
+ #endif // os(WASI)
  }
 
  internal func _createSymbolicLink(atPath path: String, withDestinationPath destPath: String) throws {
@@ -507,6 +538,11 @@ extension FileManager {
  }
 
  internal func _recursiveDestinationOfSymbolicLink(atPath path: String) throws -> String {
+ #if os(WASI)
+ // TODO: Remove this guard when realpath implementation will be released
+ // See https://github.com/WebAssembly/wasi-libc/pull/473
+ throw _NSErrorWithErrno(ENOTSUP, reading: true, path: path)
+ #else
  // Throw error if path is not a symbolic link:
  let path = try _destinationOfSymbolicLink(atPath: path)
 
@@ -520,10 +556,16 @@ extension FileManager {
  }
 
  return String(cString: resolvedPath)
+ #endif
  }
 
  /* Returns a String with a canonicalized path for the element at the specified path. */
  internal func _canonicalizedPath(toFileAtPath path: String) throws -> String {
+ #if os(WASI)
+ // TODO: Remove this guard when realpath implementation will be released
+ // See https://github.com/WebAssembly/wasi-libc/pull/473
+ throw _NSErrorWithErrno(ENOTSUP, reading: true, path: path)
+ #else
  let bufSize = Int(PATH_MAX + 1)
  var buf = [Int8](repeating: 0, count: bufSize)
  let done = try _fileSystemRepresentation(withPath: path) {
@@ -534,6 +576,7 @@ extension FileManager {
  }
 
  return self.string(withFileSystemRepresentation: buf, length: strlen(buf))
+ #endif
  }
 
  internal func _readFrom(fd: Int32, toBuffer buffer: UnsafeMutablePointer<UInt8>, length bytesToRead: Int, filename: String) throws -> Int {
@@ -591,12 +634,14 @@ extension FileManager {
  }
  defer { close(dstfd) }
 
+ #if !os(WASI) // WASI doesn't have ownership concept
  // Set the file permissions using fchmod() instead of when open()ing to avoid umask() issues
  let permissions = fileInfo.st_mode & ~S_IFMT
  guard fchmod(dstfd, permissions) == 0 else {
  throw _NSErrorWithErrno(errno, reading: false, path: dstPath,
  extraUserInfo: extraErrorInfo(srcPath: srcPath, dstPath: dstPath, userVariant: variant))
  }
+ #endif
 
  if fileInfo.st_size == 0 {
  // no copying required
@@ -741,6 +786,10 @@ extension FileManager {
  if rmdir(fsRep) == 0 {
  return
  } else if errno == ENOTEMPTY {
+ #if os(WASI)
+ // wasi-libc, which is based on musl, does not provide fts(3)
+ throw _NSErrorWithErrno(ENOTSUP, reading: false, path: path)
+ #else
  let ps = UnsafeMutablePointer<UnsafeMutablePointer<Int8>?>.allocate(capacity: 2)
  ps.initialize(to: UnsafeMutablePointer(mutating: fsRep))
  ps.advanced(by: 1).initialize(to: nil)
@@ -783,6 +832,7 @@ extension FileManager {
  } else {
  let _ = _NSErrorWithErrno(ENOTEMPTY, reading: false, path: path)
  }
+ #endif
  } else if errno != ENOTDIR {
  throw _NSErrorWithErrno(errno, reading: false, path: path)
  } else if unlink(fsRep) != 0 {
@@ -885,6 +935,7 @@ extension FileManager {
  return false
  }
 
+ #if !os(WASI) // WASI doesn't have ownership concept
  // Stat the parent directory, if that fails, return false.
  let parentS = try _lstatFile(atPath: path, withFileSystemRepresentation: parentFsRep)
 
@@ -895,6 +946,7 @@ extension FileManager {
  // If the current user owns the file, return true.
  return s.st_uid == getuid()
  }
+ #endif
 
  // Return true as the best guess.
  return true
@@ -1065,6 +1117,26 @@ extension FileManager {
  return temp._bridgeToObjectiveC().appendingPathComponent(dest)
  }
 
+ #if os(WASI)
+ // For platforms that don't support FTS, we just throw an error for now.
+ // TODO: Provide readdir(2) based implementation here or FTS in wasi-libc?
+ internal class NSURLDirectoryEnumerator : DirectoryEnumerator {
+ var _url : URL
+ var _errorHandler : ((URL, Error) -> Bool)?
+
+ init(url: URL, options: FileManager.DirectoryEnumerationOptions, errorHandler: ((URL, Error) -> Bool)?) {
+ _url = url
+ _errorHandler = errorHandler
+ }
+
+ override func nextObject() -> Any? {
+ if let handler = _errorHandler {
+ _ = handler(_url, _NSErrorWithErrno(ENOTSUP, reading: true, url: _url))
+ }
+ return nil
+ }
+ }
+ #else
  internal class NSURLDirectoryEnumerator : DirectoryEnumerator {
  var _url : URL
  var _options : FileManager.DirectoryEnumerationOptions
@@ -1198,6 +1270,7 @@ extension FileManager {
  return nil
  }
  }
+ #endif
 
  internal func _updateTimes(atPath path: String, withFileSystemRepresentation fsr: UnsafePointer<Int8>, creationTime: Date? = nil, accessTime: Date? = nil, modificationTime: Date? = nil) throws {
  let stat = try _lstatFile(atPath: path, withFileSystemRepresentation: fsr)

Sources/Foundation/FileManager.swift

@@ -21,6 +21,10 @@ import CRT
 import WinSDK
 #endif
 
+#if os(WASI)
+import WASILibc
+#endif
+
 #if os(Windows)
 internal typealias NativeFSRCharType = WCHAR
 internal let NativeFSREncoding = String.Encoding.utf16LittleEndian.rawValue
@@ -384,6 +388,10 @@ open class FileManager : NSObject {
 
  switch attribute {
  case .posixPermissions:
+#if os(WASI)
+ // WASI does not have permission concept
+ throw _NSErrorWithErrno(ENOTSUP, reading: false, path: path)
+#else
  guard let number = attributeValues[attribute] as? NSNumber else {
  fatalError("Can't set file permissions to \(attributeValues[attribute] as Any?)")
  }
@@ -400,6 +408,7 @@ open class FileManager : NSObject {
  guard result == 0 else {
  throw _NSErrorWithErrno(errno, reading: false, path: path)
  }
+#endif // os(WASI)
 
  case .modificationDate: fallthrough
  case ._accessDate:
@@ -567,6 +576,8 @@ open class FileManager : NSObject {
  result[.deviceIdentifier] = NSNumber(value: UInt64(s.st_rdev))
  let attributes = try windowsFileAttributes(atPath: path)
  let type = FileAttributeType(attributes: attributes, atPath: path)
+#elseif os(WASI)
+ let type = FileAttributeType(statMode: mode_t(s.st_mode))
 #else
  if let pwd = getpwuid(s.st_uid), pwd.pointee.pw_name != nil {
  let name = String(cString: pwd.pointee.pw_name)

Sources/Foundation/NSData.swift

@@ -498,6 +498,8 @@ open class NSData : NSObject, NSCopying, NSMutableCopying, NSSecureCoding {
  let createMode = Int(Glibc.S_IRUSR) | Int(Glibc.S_IWUSR) | Int(Glibc.S_IRGRP) | Int(Glibc.S_IWGRP) | Int(Glibc.S_IROTH) | Int(Glibc.S_IWOTH)
 #elseif canImport(Musl)
  let createMode = Int(Musl.S_IRUSR) | Int(Musl.S_IWUSR) | Int(Musl.S_IRGRP) | Int(Musl.S_IWGRP) | Int(Musl.S_IROTH) | Int(Musl.S_IWOTH)
+#elseif canImport(WASILibc)
+ let createMode = Int(WASILibc.S_IRUSR) | Int(WASILibc.S_IWUSR) | Int(WASILibc.S_IRGRP) | Int(WASILibc.S_IWGRP) | Int(WASILibc.S_IROTH) | Int(WASILibc.S_IWOTH)
 #endif
  guard let fh = FileHandle(path: path, flags: flags, createMode: createMode) else {
  throw _NSErrorWithErrno(errno, reading: false, path: path)