Fix WASI build (dirent, umask, errno and open flag tests)

Author: jrflat

Sources/CSystem/include/CSystemWASI.h

@@ -1,7 +1,7 @@
 /*
  This source file is part of the Swift System open source project
 
- Copyright (c) 2024 Apple Inc. and the Swift System project authors
+ Copyright (c) 2024 - 2025 Apple Inc. and the Swift System project authors
  Licensed under Apache License v2.0 with Runtime Library Exception
 
  See https://swift.org/LICENSE.txt for license information
@@ -11,8 +11,10 @@
 
 #if __wasi__
 
+#include <dirent.h>
 #include <errno.h>
 #include <fcntl.h>
+#include <limits.h> // For NAME_MAX
 
 // wasi-libc defines the following constants in a way that Clang Importer can't
 // understand, so we need to expose them manually.
@@ -28,4 +30,37 @@ static inline int32_t _getConst_O_WRONLY(void) { return O_WRONLY; }
 static inline int32_t _getConst_EWOULDBLOCK(void) { return EWOULDBLOCK; }
 static inline int32_t _getConst_EOPNOTSUPP(void) { return EOPNOTSUPP; }
 
+static inline uint8_t _getConst_DT_DIR(void) { return DT_DIR; }
+
+// Modified dirent struct that can be imported to Swift
+struct _system_dirent {
+  ino_t d_ino;
+  unsigned char d_type;
+  // char d_name[] cannot be imported to Swift
+  char d_name[NAME_MAX + 1];
+};
+
+// Convert WASI dirent with d_name[] to _system_dirent
+static inline
+struct _system_dirent *
+_system_dirent_from_wasi_dirent(const struct dirent *wasi_dirent) {
+
+  // Match readdir behavior and use thread-local storage for the converted dirent
+  static __thread struct _system_dirent _converted_dirent;
+
+  if (wasi_dirent == NULL) {
+    return NULL;
+  }
+
+  memset(&_converted_dirent, 0, sizeof(struct _system_dirent));
+
+  _converted_dirent.d_ino = wasi_dirent->d_ino;
+  _converted_dirent.d_type = wasi_dirent->d_type;
+
+  strncpy(_converted_dirent.d_name, wasi_dirent->d_name, NAME_MAX);
+  _converted_dirent.d_name[NAME_MAX] = '\0';
+
+  return &_converted_dirent;
+}
+
 #endif

Sources/System/FileOperations.swift

@@ -1,7 +1,7 @@
 /*
  This source file is part of the Swift System open source project
 
- Copyright (c) 2020 - 2024 Apple Inc. and the Swift System project authors
+ Copyright (c) 2020 - 2025 Apple Inc. and the Swift System project authors
  Licensed under Apache License v2.0 with Runtime Library Exception
 
  See https://swift.org/LICENSE.txt for license information
@@ -509,6 +509,7 @@ extension FileDescriptor {
   }
 }
 
+#if !os(WASI) // WASI has no umask
 extension FilePermissions {
   /// The file creation permission mask (aka "umask").
   ///
@@ -549,3 +550,4 @@ extension FilePermissions {
     return system_umask(mode)
   }
 }
+#endif

Sources/System/Internals/Syscalls.swift

@@ -1,7 +1,7 @@
 /*
  This source file is part of the Swift System open source project
 
- Copyright (c) 2020 - 2024 Apple Inc. and the Swift System project authors
+ Copyright (c) 2020 - 2025 Apple Inc. and the Swift System project authors
  Licensed under Apache License v2.0 with Runtime Library Exception
 
  See https://swift.org/LICENSE.txt for license information
@@ -14,6 +14,7 @@ import Glibc
 #elseif canImport(Musl)
 import Musl
 #elseif canImport(WASILibc)
+import CSystem
 import WASILibc
 #elseif os(Windows)
 import ucrt
@@ -189,9 +190,14 @@ internal func system_confstr(
 
 #if !os(Windows)
 internal let SYSTEM_AT_REMOVE_DIR = AT_REMOVEDIR
+#if os(WASI)
+internal let SYSTEM_DT_DIR = _getConst_DT_DIR()
+internal typealias system_dirent = _system_dirent
+#else
 internal let SYSTEM_DT_DIR = DT_DIR
 internal typealias system_dirent = dirent
-#if os(Linux) || os(Android) || os(FreeBSD) || os(OpenBSD)
+#endif
+#if os(Linux) || os(Android) || os(FreeBSD) || os(OpenBSD) || os(WASI)
 internal typealias system_DIRPtr = OpaquePointer
 #else
 internal typealias system_DIRPtr = UnsafeMutablePointer<DIR>
@@ -216,8 +222,12 @@ internal func system_fdopendir(
 
 internal func system_readdir(
   _ dir: system_DIRPtr
-) -> UnsafeMutablePointer<dirent>? {
+) -> UnsafeMutablePointer<system_dirent>? {
+  #if os(WASI)
+  return _system_dirent_from_wasi_dirent(readdir(dir))
+  #else
   return readdir(dir)
+  #endif
 }
 
 internal func system_rewinddir(
@@ -246,11 +256,13 @@ internal func system_openat(
 }
 #endif
 
+#if !os(WASI) // WASI has no umask
 internal func system_umask(
   _ mode: CInterop.Mode
 ) -> CInterop.Mode {
   return umask(mode)
 }
+#endif
 
 internal func system_getenv(
   _ name: UnsafePointer<CChar>

Tests/SystemTests/ErrnoTest.swift

@@ -1,7 +1,7 @@
 /*
  This source file is part of the Swift System open source project
 
- Copyright (c) 2020 Apple Inc. and the Swift System project authors
+ Copyright (c) 2020 - 2025 Apple Inc. and the Swift System project authors
  Licensed under Apache License v2.0 with Runtime Library Exception
 
  See https://swift.org/LICENSE.txt for license information
@@ -36,7 +36,7 @@ final class ErrnoTest: XCTestCase {
     XCTAssert(ENOMEM == Errno.noMemory.rawValue)
     XCTAssert(EACCES == Errno.permissionDenied.rawValue)
     XCTAssert(EFAULT == Errno.badAddress.rawValue)
-#if !os(Windows)
+#if !os(Windows) && !os(WASI)
     XCTAssert(ENOTBLK == Errno.notBlockDevice.rawValue)
 #endif
     XCTAssert(EBUSY == Errno.resourceBusy.rawValue)
@@ -74,9 +74,11 @@ final class ErrnoTest: XCTestCase {
     XCTAssert(WSAEOPNOTSUPP == Errno.notSupported.rawValue)
     XCTAssert(WSAEPFNOSUPPORT == Errno.protocolFamilyNotSupported.rawValue)
 #else
-    XCTAssert(ESOCKTNOSUPPORT == Errno.socketTypeNotSupported.rawValue)
     XCTAssert(ENOTSUP == Errno.notSupported.rawValue)
+#if !os(WASI)
+    XCTAssert(ESOCKTNOSUPPORT == Errno.socketTypeNotSupported.rawValue)
     XCTAssert(EPFNOSUPPORT == Errno.protocolFamilyNotSupported.rawValue)
+#endif
 #endif
     XCTAssert(EAFNOSUPPORT == Errno.addressFamilyNotSupported.rawValue)
     XCTAssert(EADDRINUSE == Errno.addressInUse.rawValue)
@@ -91,7 +93,7 @@ final class ErrnoTest: XCTestCase {
     XCTAssert(ENOTCONN == Errno.socketNotConnected.rawValue)
 #if os(Windows)
     XCTAssert(WSAESHUTDOWN == Errno.socketShutdown.rawValue)
-#else
+#elseif !os(WASI)
     XCTAssert(ESHUTDOWN == Errno.socketShutdown.rawValue)
 #endif
     XCTAssert(ETIMEDOUT == Errno.timedOut.rawValue)
@@ -100,7 +102,7 @@ final class ErrnoTest: XCTestCase {
     XCTAssert(ENAMETOOLONG == Errno.fileNameTooLong.rawValue)
 #if os(Windows)
     XCTAssert(WSAEHOSTDOWN == Errno.hostIsDown.rawValue)
-#else
+#elseif !os(WASI)
     XCTAssert(EHOSTDOWN == Errno.hostIsDown.rawValue)
 #endif
     XCTAssert(EHOSTUNREACH == Errno.noRouteToHost.rawValue)
@@ -115,7 +117,9 @@ final class ErrnoTest: XCTestCase {
     XCTAssert(WSAEDQUOT == Errno.diskQuotaExceeded.rawValue)
     XCTAssert(WSAESTALE == Errno.staleNFSFileHandle.rawValue)
 #else
+#if !os(WASI)
     XCTAssert(EUSERS == Errno.tooManyUsers.rawValue)
+#endif
     XCTAssert(EDQUOT == Errno.diskQuotaExceeded.rawValue)
     XCTAssert(ESTALE == Errno.staleNFSFileHandle.rawValue)
 #endif
@@ -171,7 +175,7 @@ final class ErrnoTest: XCTestCase {
     XCTAssert(EPROTO == Errno.protocolError.rawValue)
 #endif
 
-#if !os(Windows) && !os(FreeBSD)
+#if !os(Windows) && !os(FreeBSD) && !os(WASI)
     XCTAssert(ENODATA == Errno.noData.rawValue)
     XCTAssert(ENOSR == Errno.noStreamResources.rawValue)
     XCTAssert(ENOSTR == Errno.notStream.rawValue)
@@ -181,11 +185,13 @@ final class ErrnoTest: XCTestCase {
     XCTAssert(EOPNOTSUPP == Errno.notSupportedOnSocket.rawValue)
 
     // From headers but not man page
+#if !os(WASI) // Would need to use _getConst func from CSystem
     XCTAssert(EWOULDBLOCK == Errno.wouldBlock.rawValue)
+#endif
 #if os(Windows)
     XCTAssert(WSAETOOMANYREFS == Errno.tooManyReferences.rawValue)
     XCTAssert(WSAEREMOTE == Errno.tooManyRemoteLevels.rawValue)
-#else
+#elseif !os(WASI)
     XCTAssert(ETOOMANYREFS == Errno.tooManyReferences.rawValue)
     XCTAssert(EREMOTE == Errno.tooManyRemoteLevels.rawValue)
 #endif

Tests/SystemTests/FileOperationsTest.swift

@@ -1,7 +1,7 @@
 /*
  This source file is part of the Swift System open source project
 
- Copyright (c) 2020 Apple Inc. and the Swift System project authors
+ Copyright (c) 2020 - 2025 Apple Inc. and the Swift System project authors
  Licensed under Apache License v2.0 with Runtime Library Exception
 
  See https://swift.org/LICENSE.txt for license information
@@ -16,10 +16,13 @@ import XCTest
 #endif
 #if canImport(Android)
 import Android
+#elseif os(WASI)
+import CSystem
 #endif
 
 @available(/*System 0.0.1: macOS 11.0, iOS 14.0, watchOS 7.0, tvOS 14.0*/iOS 8, *)
 final class FileOperationsTest: XCTestCase {
+  #if !os(WASI) // Would need to use _getConst funcs from CSystem
   func testSyscalls() {
     let fd = FileDescriptor(rawValue: 1)
 
@@ -88,6 +91,7 @@ final class FileOperationsTest: XCTestCase {
 
     for test in syscallTestCases { test.runAllTests() }
   }
+  #endif // !os(WASI)
 
   func testWriteFromEmptyBuffer() throws {
     #if os(Windows)
@@ -153,6 +157,7 @@ final class FileOperationsTest: XCTestCase {
     // TODO: Test writeAll, writeAll(toAbsoluteOffset), closeAfter
   }
 
+  #if !os(WASI) // WASI has no pipe
   func testAdHocPipe() throws {
     // Ad-hoc test testing `Pipe` functionality.
     // We cannot test `Pipe` using `MockTestCase` because it calls `pipe` with a pointer to an array local to the `Pipe`, the address of which we do not know prior to invoking `Pipe`.
@@ -171,6 +176,7 @@ final class FileOperationsTest: XCTestCase {
       }
     }
   }
+  #endif
 
   func testAdHocOpen() {
     // Ad-hoc test touching a file system.
@@ -211,8 +217,13 @@ final class FileOperationsTest: XCTestCase {
 
   func testGithubIssues() {
     // https://github.com/apple/swift-system/issues/26
+    #if os(WASI)
+    let openOptions = _getConst_O_WRONLY() | _getConst_O_CREAT()
+    #else
+    let openOptions = O_WRONLY | O_CREAT
+    #endif
     let issue26 = MockTestCase(
-      name: "open", .interruptable, "a path", O_WRONLY | O_CREAT, 0o020
+      name: "open", .interruptable, "a path", openOptions, 0o020
     ) {
       retryOnInterrupt in
       _ = try FileDescriptor.open(
@@ -221,7 +232,6 @@ final class FileOperationsTest: XCTestCase {
         retryOnInterrupt: retryOnInterrupt)
     }
     issue26.runAllTests()
-
   }
 
   func testResizeFile() throws {

Tests/SystemTests/FileTypesTest.swift

@@ -1,7 +1,7 @@
 /*
  This source file is part of the Swift System open source project
 
- Copyright (c) 2020 - 2021 Apple Inc. and the Swift System project authors
+ Copyright (c) 2020 - 2025 Apple Inc. and the Swift System project authors
  Licensed under Apache License v2.0 with Runtime Library Exception
 
  See https://swift.org/LICENSE.txt for license information
@@ -32,13 +32,15 @@ final class FileDescriptorTest: XCTestCase {
     XCTAssertEqual(O_WRONLY, FileDescriptor.AccessMode.writeOnly.rawValue)
     XCTAssertEqual(O_RDWR, FileDescriptor.AccessMode.readWrite.rawValue)
 
+#if !os(WASI) // Would need to use _getConst funcs from CSystem
 #if !os(Windows)
     XCTAssertEqual(O_NONBLOCK, FileDescriptor.OpenOptions.nonBlocking.rawValue)
 #endif
     XCTAssertEqual(O_APPEND, FileDescriptor.OpenOptions.append.rawValue)
     XCTAssertEqual(O_CREAT, FileDescriptor.OpenOptions.create.rawValue)
     XCTAssertEqual(O_TRUNC, FileDescriptor.OpenOptions.truncate.rawValue)
     XCTAssertEqual(O_EXCL, FileDescriptor.OpenOptions.exclusiveCreate.rawValue)
+#endif // !os(WASI
 #if !os(Windows)
     XCTAssertEqual(O_NOFOLLOW, FileDescriptor.OpenOptions.noFollow.rawValue)
     XCTAssertEqual(O_CLOEXEC, FileDescriptor.OpenOptions.closeOnExec.rawValue)