Merge pull request #584 from kateinoigakukun/yt/wasi-support

Complete WebAssembly/WASI Support

Author: kateinoigakukun

Package.swift

@@ -130,7 +130,6 @@ extension Array where Element == PackageDescription.SwiftSetting {
 
       .define("SWT_TARGET_OS_APPLE", .when(platforms: [.macOS, .iOS, .macCatalyst, .watchOS, .tvOS, .visionOS])),
 
-      .define("SWT_NO_FILE_IO", .when(platforms: [.wasi])),
       .define("SWT_NO_EXIT_TESTS", .when(platforms: [.iOS, .watchOS, .tvOS, .visionOS, .wasi])),
       .define("SWT_NO_SNAPSHOT_TYPES", .when(platforms: [.linux, .windows, .wasi])),
       .define("SWT_NO_DYNAMIC_LINKING", .when(platforms: [.wasi])),

README.md

@@ -102,6 +102,7 @@ for various platforms:
 | **visionOS** | | | Supported |
 | **Ubuntu 22.04** | [![Build Status](https://ci.swift.org/buildStatus/icon?job=swift-testing-main-swift-6.0-linux)](https://ci.swift.org/job/swift-testing-main-swift-6.0-linux/) | [![Build Status](https://ci.swift.org/buildStatus/icon?job=swift-testing-main-swift-main-linux)](https://ci.swift.org/view/Swift%20Packages/job/swift-testing-main-swift-main-linux/) | Supported |
 | **Windows** | | [![Build Status](https://ci-external.swift.org/buildStatus/icon?job=swift-testing-main-swift-main-windows)](https://ci-external.swift.org/job/swift-testing-main-swift-main-windows/) | Supported |
+| **Wasm** | | | Experimental |
 
 ### Works with XCTest
 

Sources/Testing/Support/FileHandle.swift

@@ -141,7 +141,7 @@ struct FileHandle: ~Copyable, Sendable {
   /// descriptor, `nil` is passed to `body`.
   borrowing func withUnsafePOSIXFileDescriptor<R>(_ body: (CInt?) throws -> R) rethrows -> R {
     try withUnsafeCFILEHandle { handle in
-#if SWT_TARGET_OS_APPLE || os(Linux)
+#if SWT_TARGET_OS_APPLE || os(Linux) || os(WASI)
       let fd = fileno(handle)
 #elseif os(Windows)
       let fd = _fileno(handle)
@@ -210,6 +210,8 @@ struct FileHandle: ~Copyable, Sendable {
       defer {
         _unlock_file(handle)
       }
+#elseif os(WASI)
+      // No file locking on WASI yet.
 #else
 #warning("Platform-specific implementation missing: cannot lock a file handle")
 #endif
@@ -233,7 +235,7 @@ extension FileHandle {
     // If possible, reserve enough space in the resulting buffer to contain
     // the contents of the file being read.
     var size: Int?
-#if SWT_TARGET_OS_APPLE || os(Linux)
+#if SWT_TARGET_OS_APPLE || os(Linux) || os(WASI)
     withUnsafePOSIXFileDescriptor { fd in
       var s = stat()
       if let fd, 0 == fstat(fd, &s) {
@@ -371,7 +373,7 @@ extension FileHandle {
 extension FileHandle {
   /// Is this file handle a TTY or PTY?
   var isTTY: Bool {
-#if SWT_TARGET_OS_APPLE || os(Linux)
+#if SWT_TARGET_OS_APPLE || os(Linux) || os(WASI)
     // If stderr is a TTY and TERM is set, that's good enough for us.
     withUnsafePOSIXFileDescriptor { fd in
       if let fd, 0 != isatty(fd), let term = Environment.variable(named: "TERM"), !term.isEmpty {
@@ -397,7 +399,7 @@ extension FileHandle {
 
   /// Is this file handle a pipe or FIFO?
   var isPipe: Bool {
-#if SWT_TARGET_OS_APPLE || os(Linux)
+#if SWT_TARGET_OS_APPLE || os(Linux) || os(WASI)
     withUnsafePOSIXFileDescriptor { fd in
       guard let fd else {
         return false

Sources/Testing/Support/Locked.swift

@@ -42,6 +42,7 @@ struct Locked<T>: RawRepresentable, Sendable where T: Sendable {
   private typealias _Lock = SRWLOCK
 #elseif os(WASI)
   // No locks on WASI without multithreaded runtime.
+  private typealias _Lock = Void
 #else
 #warning("Platform-specific implementation missing: locking unavailable")
   private typealias _Lock = Void

Sources/Testing/Traits/Tags/Tag.Color+Loading.swift

@@ -49,22 +49,29 @@ private var _appDataDirectoryPath: String? {
 /// On Apple platforms and on Linux, this path is equivalent to
 /// `"~/.swift-testing"`. On Windows, it is equivalent to
 /// `"%HOMEPATH%\AppData\Local\.swift-testing"`.
-var swiftTestingDirectoryPath: String {
+/// The value of this property is `nil` if the platform does not support the
+/// concept of a home directory, or if the home directory could not be
+/// determined.
+var swiftTestingDirectoryPath: String? {
   // The (default) name of the .swift-testing directory.
   let swiftTestingDirectoryName = ".swift-testing"
 
 #if os(macOS) || (os(iOS) && targetEnvironment(macCatalyst)) || os(Linux)
   if let homeDirectoryPath = _homeDirectoryPath {
     return appendPathComponent(swiftTestingDirectoryName, to: homeDirectoryPath)
   }
+  return nil
 #elseif os(Windows)
   if let appDataDirectoryPath = _appDataDirectoryPath {
     return appendPathComponent(swiftTestingDirectoryName, to: appDataDirectoryPath)
   }
+  return nil
+#elseif os(WASI)
+  return nil
 #else
 #warning("Platform-specific implementation missing: .swift-testing directory location unavailable")
+  return nil
 #endif
-  return ""
 }
 
 /// Read tag colors out of the file `"tag-colors.json"` in a given directory.
@@ -83,7 +90,12 @@ var swiftTestingDirectoryPath: String {
 /// assumed to contain a JSON object (a dictionary) where the keys are tags'
 /// string values and the values represent tag colors. For a list of the
 /// supported formats for tag colors in this dictionary, see <doc:AddingTags>.
-func loadTagColors(fromFileInDirectoryAtPath swiftTestingDirectoryPath: String = swiftTestingDirectoryPath) throws -> [Tag: Tag.Color] {
+func loadTagColors(fromFileInDirectoryAtPath swiftTestingDirectoryPath: String? = swiftTestingDirectoryPath) throws -> [Tag: Tag.Color] {
+  guard let swiftTestingDirectoryPath else {
+    // If the platform does not support user-specific configuration, skip custom
+    // tag colors.
+    return [:]
+  }
   // Find the path to the tag-colors.json file and try to load its contents.
   let tagColorsPath = appendPathComponent("tag-colors.json", to: swiftTestingDirectoryPath)
   let fileHandle = try FileHandle(forReadingAtPath: tagColorsPath)

Sources/_TestingInternals/Discovery.cpp

@@ -86,6 +86,26 @@ struct SWTRelativePointer {
   }
 };
 
+/// A type representing a 32-bit absolute function pointer, usually used on platforms
+/// where relative function pointers are not supported.
+///
+/// This type is derived from `AbsoluteFunctionPointer` in the Swift repository.
+template <typename T>
+struct SWTAbsoluteFunctionPointer {
+private:
+  T *_pointer;
+  static_assert(sizeof(T *) == sizeof(int32_t), "Function pointer must be 32-bit when using compact absolute pointer");
+
+public:
+  const T *_Nullable get(void) const & {
+    return _pointer;
+  }
+
+  const T *_Nullable operator ->(void) const & {
+    return get();
+  }
+};
+
 /// A type representing a pointer relative to itself with low bits reserved for
 /// use as flags.
 ///
@@ -98,6 +118,13 @@ struct SWTRelativePointerIntPair: public SWTRelativePointer<T, maskValue> {
   }
 };
 
+template <typename T>
+#if defined(__wasm32__)
+using SWTCompactFunctionPointer = SWTAbsoluteFunctionPointer<T>;
+#else
+using SWTCompactFunctionPointer = SWTRelativePointer<T>;
+#endif
+
 /// A type representing a metatype as constructed during compilation of a Swift
 /// module.
 ///
@@ -114,7 +141,7 @@ struct SWTTypeContextDescriptor {
     size_t state;
   };
   using MetadataAccessFunction = __attribute__((swiftcall)) MetadataAccessResponse(size_t);
-  SWTRelativePointer<MetadataAccessFunction> _metadataAccessFunction;
+  SWTCompactFunctionPointer<MetadataAccessFunction> _metadataAccessFunction;
 
 public:
   const char *_Nullable getName(void) const& {

Sources/_TestingInternals/include/Includes.h

@@ -27,7 +27,11 @@
 /// - Note: Avoid including headers that aren't actually used.
 
 #include <errno.h>
-#if __has_include(<signal.h>)
+/// Guard against including `signal.h` on WASI. The `signal.h` header file
+/// itself is available in wasi-libc, but it's just a stub that doesn't actually
+/// do anything. And also including it requires a special macro definition
+/// (`_WASI_EMULATED_SIGNAL`) and it causes compilation errors without the macro.
+#if __has_include(<signal.h>) && !defined(__wasi__)
 #include <signal.h>
 #endif
 #include <stdio.h>

cmake/modules/shared/CompilerSettings.cmake

@@ -20,9 +20,6 @@ add_compile_options(
 if(APPLE)
   add_compile_definitions("SWT_TARGET_OS_APPLE")
 endif()
-if(WASI)
-  add_compile_definitions("SWT_NO_FILE_IO")
-endif()
 if(CMAKE_SYSTEM_NAME IN_LIST "iOS;watchOS;tvOS;visionOS;WASI")
   add_compile_definitions("SWT_NO_EXIT_TESTS")
 endif()