Expose the target triple as a separate string from the testing library version.

Package.swift

@@ -170,7 +170,7 @@ extension Array where Element == PackageDescription.CXXSetting {
       } else {
         git.currentCommit
       }
-      result.append(.define("_SWT_TESTING_LIBRARY_VERSION", to: #""\#(testingLibraryVersion)""#))
+      result.append(.define("SWT_TESTING_LIBRARY_VERSION", to: #""\#(testingLibraryVersion)""#))
     }
 
     return result

Sources/Testing/Events/Recorder/Event.HumanReadableOutputRecorder.swift

@@ -310,6 +310,9 @@ extension Event.HumanReadableOutputRecorder {
         comments.append("Swift Version: \(swiftStandardLibraryVersion)")
       }
       comments.append("Testing Library Version: \(testingLibraryVersion)")
+      if let targetTriple {
+        comments.append("Target Platform: \(targetTriple)")
+      }
       if verbosity > 0 {
 #if targetEnvironment(simulator)
         comments.append("OS Version (Simulator): \(simulatorVersion)")

Sources/Testing/Support/Versions.swift

@@ -88,8 +88,8 @@ let operatingSystemVersion: String = {
     }
   }
 #elseif os(WASI)
-  if let libcVersion = swt_getWASIVersion().flatMap(String.init(validatingCString:)), !libcVersion.isEmpty {
-    return "WASI with libc \(libcVersion)"
+  if let version = swt_getWASIVersion().flatMap(String.init(validatingCString:)) {
+    return version
   }
 #else
 #warning("Platform-specific implementation missing: OS version unavailable")
@@ -132,6 +132,13 @@ var testingLibraryVersion: String {
   swt_getTestingLibraryVersion().flatMap(String.init(validatingCString:)) ?? "unknown"
 }
 
+/// Get the LLVM target triple used to build the testing library, if available.
+///
+/// This value is not part of the public interface of the testing library.
+var targetTriple: String? {
+  swt_getTargetTriple().flatMap(String.init(validatingCString:))
+}
+
 /// A human-readable string describing the Swift Standard Library's version.
 ///
 /// This value's format is platform-specific and is not meant to be

Sources/_TestingInternals/CMakeLists.txt

@@ -9,6 +9,7 @@
 set(CMAKE_CXX_SCAN_FOR_MODULES 0)
 
 include(LibraryVersion)
+include(TargetTriple)
 add_library(_TestingInternals STATIC
   Discovery.cpp
   Versions.cpp

Sources/_TestingInternals/Versions.cpp

@@ -10,11 +10,32 @@
 
 #include "Versions.h"
 
+#if defined(_SWT_TESTING_LIBRARY_VERSION) && !defined(SWT_TESTING_LIBRARY_VERSION)
+#warning _SWT_TESTING_LIBRARY_VERSION is deprecated
+#warning Define SWT_TESTING_LIBRARY_VERSION and optionally SWT_TARGET_TRIPLE instead
+#define SWT_TESTING_LIBRARY_VERSION _SWT_TESTING_LIBRARY_VERSION
+#endif
+
 const char *swt_getTestingLibraryVersion(void) {
-#if defined(_SWT_TESTING_LIBRARY_VERSION)
-  return _SWT_TESTING_LIBRARY_VERSION;
+#if defined(SWT_TESTING_LIBRARY_VERSION)
+  return SWT_TESTING_LIBRARY_VERSION;
+#else
+#warning SWT_TESTING_LIBRARY_VERSION not defined: testing library version is unavailable
+  return nullptr;
+#endif
+}
+
+const char *swt_getTargetTriple(void) {
+#if defined(SWT_TARGET_TRIPLE)
+  return SWT_TARGET_TRIPLE;
 #else
-#warning _SWT_TESTING_LIBRARY_VERSION not defined: testing library version is unavailable
+  // If we're here, we're presumably building as a package. Swift Package
+  // Manager does not provide a way to get the target triple from within the
+  // package manifest. SEE: swift-package-manager-#7929
+  //
+  // clang has __is_target_*() intrinsics, but we don't want to play a game of
+  // Twenty Questions in order to synthesize the triple (and still potentially
+  // get it wrong.) SEE: rdar://134933385
   return nullptr;
 #endif
 }

Sources/_TestingInternals/include/Includes.h

@@ -39,15 +39,6 @@
 #include <string.h>
 #include <time.h>
 
-#if defined(__APPLE__) && !SWT_NO_MACH_PORTS
-#include <mach/mach_init.h>
-#include <mach/task.h>
-#endif
-
-#if defined(__APPLE__) && !SWT_NO_LIBDISPATCH
-#include <dispatch/dispatch.h>
-#endif
-
 #if __has_include(<unistd.h>)
 #include <unistd.h>
 #endif
@@ -106,10 +97,6 @@
 #include <crt_externs.h>
 #endif
 
-#if __has_include(<wasi/libc-environ.h>)
-#include <wasi/libc-environ.h>
-#endif
-
 #if __has_include(<libgen.h>)
 #include <libgen.h>
 #endif
@@ -122,13 +109,36 @@
 #include <sysexits.h>
 #endif
 
+// MARK: - Platform-specific includes
+
+#if defined(__APPLE__)
+#if !SWT_NO_MACH_PORTS
+#include <mach/mach_init.h>
+#include <mach/task.h>
+#endif
+
+#if !SWT_NO_LIBDISPATCH
+#include <dispatch/dispatch.h>
+#endif
+#endif
+
 #if defined(_WIN32)
 #define WIN32_LEAN_AND_MEAN
 #define NOMINMAX
 #include <Windows.h>
 #include <Psapi.h>
 #endif
 
+#if defined(__wasi__)
+#if __has_include(<wasi/libc-environ.h>)
+#include <wasi/libc-environ.h>
+#endif
+
+#if __has_include(<wasi/version.h>)
+#include <wasi/version.h>
+#endif
+#endif
+
 #if defined(__ANDROID__)
 #pragma clang module import posix_filesystem.linux_stat
 #include <sys/system_properties.h>

Sources/_TestingInternals/include/Stubs.h

@@ -134,24 +134,6 @@ static int swt_siginfo_t_si_status(const siginfo_t *siginfo) {
 #endif
 #endif
 
-#if defined(__wasi__)
-/// Get the version of the C standard library and runtime used by WASI, if
-/// available.
-///
-/// This function is provided because `WASI_LIBC_VERSION` may or may not be
-/// defined and may or may not be a complex macro.
-///
-/// For more information about the `WASI_LIBC_VERSION` macro, see
-/// [wasi-libc-#490](https://github.com/WebAssembly/wasi-libc/issues/490).
-static const char *_Nullable swt_getWASIVersion(void) {
-#if defined(WASI_LIBC_VERSION)
-  return WASI_LIBC_VERSION;
-#else
-  return 0;
-#endif
-}
-#endif
-
 SWT_ASSUME_NONNULL_END
 
 #endif

Sources/_TestingInternals/include/Versions.h

@@ -12,6 +12,7 @@
 #define SWT_VERSIONS_H
 
 #include "Defines.h"
+#include "Includes.h"
 
 SWT_ASSUME_NONNULL_BEGIN
 
@@ -23,6 +24,30 @@ SWT_ASSUME_NONNULL_BEGIN
 ///   other conditions. Do not attempt to parse it.
 SWT_EXTERN const char *_Nullable swt_getTestingLibraryVersion(void);
 
+/// Get the LLVM target triple used to build the testing library.
+///
+/// - Returns: A string containing the LLVM target triple used to build the
+///   testing library, or `nullptr` if that information is not available.
+SWT_EXTERN const char *_Nullable swt_getTargetTriple(void);
+
+#if defined(__wasi__)
+/// Get the version of the C standard library and runtime used by WASI, if
+/// available.
+///
+/// This function is provided because `WASI_SDK_VERSION` may or may not be
+/// defined and may or may not be a complex macro.
+///
+/// For more information about the `WASI_SDK_VERSION` macro, see
+/// [wasi-libc-#490](https://github.com/WebAssembly/wasi-libc/issues/490).
+static const char *_Nullable swt_getWASIVersion(void) {
+#if defined(WASI_SDK_VERSION)
+  return WASI_SDK_VERSION;
+#else
+  return 0;
+#endif
+}
+#endif
+
 SWT_ASSUME_NONNULL_END
 
 #endif

cmake/modules/LibraryVersion.cmake

@@ -40,4 +40,4 @@ endif()
 # All done!
 message(STATUS "Swift Testing version: ${SWT_TESTING_LIBRARY_VERSION}")
 add_compile_definitions(
-  "$<$<COMPILE_LANGUAGE:CXX>:_SWT_TESTING_LIBRARY_VERSION=\"${SWT_TESTING_LIBRARY_VERSION}\">")
+  "$<$<COMPILE_LANGUAGE:CXX>:SWT_TESTING_LIBRARY_VERSION=\"${SWT_TESTING_LIBRARY_VERSION}\">")

cmake/modules/TargetTriple.cmake

@@ -0,0 +1,22 @@
+# This source file is part of the Swift.org open source project
+#
+# Copyright (c) 2024 Apple Inc. and the Swift project authors
+# Licensed under Apache License v2.0 with Runtime Library Exception
+#
+# See http://swift.org/LICENSE.txt for license information
+# See http://swift.org/CONTRIBUTORS.txt for Swift project authors
+
+# Ask the Swift compiler what target triple it will be compiling with today.
+set(SWT_TARGET_INFO_COMMAND "${CMAKE_Swift_COMPILER}" -print-target-info)
+if(CMAKE_Swift_COMPILER_TARGET)
+  list(APPEND SWT_TARGET_INFO_COMMAND -target ${CMAKE_Swift_COMPILER_TARGET})
+endif()
+execute_process(COMMAND ${SWT_TARGET_INFO_COMMAND} OUTPUT_VARIABLE SWT_TARGET_INFO_JSON)
+string(JSON SWT_TARGET_TRIPLE GET "${SWT_TARGET_INFO_JSON}" "target" "unversionedTriple")
+
+# All done!
+message(STATUS "Swift Testing target triple: ${SWT_TARGET_TRIPLE}")
+if(SWT_TARGET_TRIPLE)
+  add_compile_definitions(
+    "$<$<COMPILE_LANGUAGE:CXX>:SWT_TARGET_TRIPLE=\"${SWT_TARGET_TRIPLE}\">")
+endif()