Expose the target triple as a separate string from the testing library version. (#652)

This PR adds a script to our CMake build to capture the target triple
being used to build Swift Testing so that we can include it in our
diagnostic output.

Apple's fork of Swift Testing (as included with Xcode 16) also includes
this information, and it is very useful to have when reviewing bug
reports as it can tell us if a problem is specific to a given
architecture or OS variant.

### Checklist:

- [x] Code and documentation should follow the style of the [Style
Guide](https://github.com/apple/swift-testing/blob/main/Documentation/StyleGuide.md).
- [x] If public symbols are renamed or modified, DocC references should
be updated.

Author: grynspan

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()