Introduce VisionOS Platform

This change introduces a new compilation target platform to the Swift compiler - visionOS.

- Changes to the compiler build infrastrucuture to support building compiler-adjacent artifacts and test suites for the new target.
- Addition of the new platform kind definition.
- Support for the new platform in language constructs such as compile-time availability annotations or runtime OS version queries.
- Utilities to read out Darwin platform SDK info containing platform mapping data.
- Utilities to support re-mapping availability annotations from iOS to visionOS (e.g. 'updateIntroducedPlatformForFallback', 'updateDeprecatedPlatformForFallback', 'updateObsoletedPlatformForFallback').
- Additional tests exercising platform-specific availability handling and availability re-mapping fallback code-path.
- Changes to existing test suite to accomodate the new platform.

Author: artemcm

CMakeLists.txt

@@ -119,7 +119,7 @@ set(SWIFT_DARWIN_EMBEDDED_VARIANTS "^(iphoneos|iphonesimulator|appletvos|appletv
 #  if("${SWIFT_HOST_VARIANT_SDK}" IN_LIST SWIFT_DARWIN_PLATFORMS)
 #    ...
 #  endif()
-set(SWIFT_DARWIN_PLATFORMS "IOS" "IOS_SIMULATOR" "TVOS" "TVOS_SIMULATOR" "WATCHOS" "WATCHOS_SIMULATOR" "OSX")
+set(SWIFT_DARWIN_PLATFORMS "IOS" "IOS_SIMULATOR" "TVOS" "TVOS_SIMULATOR" "WATCHOS" "WATCHOS_SIMULATOR" "OSX" "XROS" "XROS_SIMULATOR")
 
 set(SWIFT_APPLE_PLATFORMS ${SWIFT_DARWIN_PLATFORMS})
 if(SWIFT_FREESTANDING_FLAVOR STREQUAL "apple")
@@ -542,6 +542,9 @@ set(SWIFT_DARWIN_DEPLOYMENT_VERSION_TVOS "11.0" CACHE STRING
 set(SWIFT_DARWIN_DEPLOYMENT_VERSION_WATCHOS "4.0" CACHE STRING
     "Minimum deployment target version for watchOS")
 
+set(SWIFT_DARWIN_DEPLOYMENT_VERSION_XROS "1.0" CACHE STRING
+    "Minimum deployment target version for xrOS")
+
 #
 #  Compatibility library deployment versions
 #
@@ -550,6 +553,7 @@ set(COMPATIBILITY_MINIMUM_DEPLOYMENT_VERSION_OSX "10.9")
 set(COMPATIBILITY_MINIMUM_DEPLOYMENT_VERSION_IOS "7.0")
 set(COMPATIBILITY_MINIMUM_DEPLOYMENT_VERSION_TVOS "9.0")
 set(COMPATIBILITY_MINIMUM_DEPLOYMENT_VERSION_WATCHOS "2.0")
+set(COMPATIBILITY_MINIMUM_DEPLOYMENT_VERSION_XROS "1.0")
 set(COMPATIBILITY_MINIMUM_DEPLOYMENT_VERSION_MACCATALYST "13.1")
 
 #
@@ -595,7 +599,7 @@ option(SWIFT_REPORT_STATISTICS
     FALSE)
 
 # Only Darwin platforms enable ObjC interop by default.
-if("${SWIFT_HOST_VARIANT_SDK}" MATCHES "(OSX|IOS*|TVOS*|WATCHOS*)")
+if("${SWIFT_HOST_VARIANT_SDK}" MATCHES "(OSX|IOS*|TVOS*|WATCHOS*|XROS*)")
   set(SWIFT_STDLIB_ENABLE_OBJC_INTEROP_default TRUE)
 else()
   set(SWIFT_STDLIB_ENABLE_OBJC_INTEROP_default FALSE)
@@ -1139,7 +1143,7 @@ elseif("${SWIFT_HOST_VARIANT_SDK}" STREQUAL "WASI")
   set(SWIFT_PRIMARY_VARIANT_SDK_default  "${SWIFT_HOST_VARIANT_SDK}")
   set(SWIFT_PRIMARY_VARIANT_ARCH_default "${SWIFT_HOST_VARIANT_ARCH}")
 
-elseif("${SWIFT_HOST_VARIANT_SDK}" MATCHES "(OSX|IOS*|TVOS*|WATCHOS*)")
+elseif("${SWIFT_HOST_VARIANT_SDK}" MATCHES "(OSX|IOS*|TVOS*|WATCHOS*|XROS*)")
 
   set(SWIFT_HOST_VARIANT "macosx" CACHE STRING
       "Deployment OS for Swift host tools (the compiler) [macosx, iphoneos].")

cmake/modules/DarwinSDKs.cmake

@@ -15,6 +15,8 @@ set(SUPPORTED_TVOS_SIMULATOR_ARCHS "x86_64;arm64")
 set(SUPPORTED_WATCHOS_ARCHS "armv7k;arm64_32")
 set(SUPPORTED_WATCHOS_SIMULATOR_ARCHS "i386;x86_64;arm64")
 set(SUPPORTED_OSX_ARCHS "x86_64;arm64")
+set(SUPPORTED_XROS_ARCHS "arm64;arm64e")
+set(SUPPORTED_XROS_SIMULATOR_ARCHS "arm64")
 
 is_sdk_requested(OSX swift_build_osx)
 if(swift_build_osx)
@@ -50,7 +52,8 @@ if(swift_build_freestanding AND (SWIFT_FREESTANDING_FLAVOR STREQUAL "apple"))
 endif()
 
 # Compatible cross-compile SDKS for Darwin OSes: IOS, IOS_SIMULATOR, TVOS,
-#   TVOS_SIMULATOR, WATCHOS, WATCHOS_SIMULATOR (archs hardcoded below).
+#   TVOS_SIMULATOR, WATCHOS, WATCHOS_SIMULATOR, XROS, XROS_SIMULATOR
+#   (archs hardcoded below).
 
 is_sdk_requested(IOS swift_build_ios)
 if(swift_build_ios)
@@ -120,3 +123,28 @@ if(swift_build_watchos_simulator)
   configure_target_variant(WATCHOS_SIMULATOR-RA "watchOS Release+Asserts" WATCHOS_SIMULATOR RA "Release+Asserts")
   configure_target_variant(WATCHOS_SIMULATOR-R  "watchOS Release"         WATCHOS_SIMULATOR R "Release")
 endif()
+
+is_sdk_requested(XROS swift_build_xros)
+if(swift_build_xros)
+  configure_sdk_darwin(
+      XROS "xrOS" "${SWIFT_DARWIN_DEPLOYMENT_VERSION_XROS}"
+      xros xros xros "${SUPPORTED_XROS_ARCHS}")
+  configure_target_variant(XROS-DA "xrOS Debug+Asserts"   XROS DA "Debug+Asserts")
+  configure_target_variant(XROS-RA "xrOS Release+Asserts" XROS RA "Release+Asserts")
+  configure_target_variant(XROS-R  "xrOS Release"         XROS R "Release")
+endif()
+
+is_sdk_requested(XROS_SIMULATOR swift_build_xros_simulator)
+if(swift_build_xros_simulator)
+  configure_sdk_darwin(
+      XROS_SIMULATOR "xrOS Simulator" "${SWIFT_DARWIN_DEPLOYMENT_VERSION_XROS}"
+      xrsimulator xros xros-simulator
+      "${SUPPORTED_XROS_SIMULATOR_ARCHS}")
+
+  configure_target_variant(
+      XROS_SIMULATOR-DA "xrOS Simulator Debug+Asserts"   XROS_SIMULATOR DA "Debug+Asserts")
+  configure_target_variant(
+      XROS_SIMULATOR-RA "xrOS Simulator Release+Asserts" XROS_SIMULATOR RA "Release+Asserts")
+  configure_target_variant(
+      XROS_SIMULATOR-R  "xrOS Simulator Release"         XROS_SIMULATOR R "Release")
+endif()

cmake/modules/StandaloneOverlay.cmake

@@ -100,7 +100,7 @@ set(CMAKE_INSTALL_PREFIX
 
 
 set(SWIFT_DARWIN_PLATFORMS
-  OSX IOS IOS_SIMULATOR TVOS TVOS_SIMULATOR WATCHOS WATCHOS_SIMULATOR)
+  OSX IOS IOS_SIMULATOR TVOS TVOS_SIMULATOR WATCHOS WATCHOS_SIMULATOR XROS XROS_SIMULATOR)
 
 # Flags used to indicate we are building a standalone overlay.
 # FIXME: We should cut this down to a single flag.

include/swift/AST/ASTContext.h

@@ -34,6 +34,7 @@
 #include "swift/Basic/BlockList.h"
 #include "swift/SymbolGraphGen/SymbolGraphOptions.h"
 #include "clang/AST/DeclTemplate.h"
+#include "clang/Basic/DarwinSDKInfo.h"
 #include "llvm/ADT/ArrayRef.h"
 #include "llvm/ADT/DenseMap.h"
 #include "llvm/ADT/IntrusiveRefCntPtr.h"
@@ -948,6 +949,12 @@ class ASTContext final {
     return getMultiPayloadEnumTagSinglePayloadAvailability();
   }
 
+  /// Test support utility for loading a platform remap file
+  /// in case an SDK is not specified to the compilation.
+  const clang::DarwinSDKInfo::RelatedTargetVersionMapping *
+  getAuxiliaryDarwinPlatformRemapInfo(
+      clang::DarwinSDKInfo::OSEnvPair Kind) const;
+
   //===--------------------------------------------------------------------===//
   // Diagnostics Helper functions
   //===--------------------------------------------------------------------===//
@@ -1511,6 +1518,9 @@ class ASTContext final {
   /// Provide context-level uniquing for SIL lowered type layouts and boxes.
   friend SILLayout;
   friend SILBoxType;
+
+public:
+  clang::DarwinSDKInfo *getDarwinSDKInfo() const;
 };
 
 } // end namespace swift

include/swift/AST/Availability.h

@@ -25,6 +25,7 @@
 namespace swift {
 class ASTContext;
 class AvailableAttr;
+class BackDeployedAttr;
 class Decl;
 
 /// A lattice of version ranges of the form [x.y.z, +Inf).
@@ -380,6 +381,39 @@ class AvailabilityInference {
 
   static AvailabilityContext
   annotatedAvailableRangeForAttr(const SpecializeAttr *attr, ASTContext &ctx);
+
+  /// For the attribute's introduction version, update the platform and version
+  /// values to the re-mapped platform's, if using a fallback platform.
+  /// Returns `true` if a remap occured.
+  static bool updateIntroducedPlatformForFallback(
+      const AvailableAttr *attr, const ASTContext &Ctx,
+      llvm::StringRef &Platform, llvm::VersionTuple &PlatformVer);
+
+  /// For the attribute's deprecation version, update the platform and version
+  /// values to the re-mapped platform's, if using a fallback platform.
+  /// Returns `true` if a remap occured.
+  static bool updateDeprecatedPlatformForFallback(
+      const AvailableAttr *attr, const ASTContext &Ctx,
+      llvm::StringRef &Platform, llvm::VersionTuple &PlatformVer);
+
+  /// For the attribute's obsoletion version, update the platform and version
+  /// values to the re-mapped platform's, if using a fallback platform.
+  /// Returns `true` if a remap occured.
+  static bool updateObsoletedPlatformForFallback(
+      const AvailableAttr *attr, const ASTContext &Ctx,
+      llvm::StringRef &Platform, llvm::VersionTuple &PlatformVer);
+
+  static void updatePlatformStringForFallback(
+      const AvailableAttr *attr, const ASTContext &Ctx,
+      llvm::StringRef &Platform);
+
+  /// For the attribute's before version, update the platform and version
+  /// values to the re-mapped platform's, if using a fallback platform.
+  /// Returns `true` if a remap occured.
+  static bool updateBeforePlatformForFallback(const BackDeployedAttr *attr,
+                                              const ASTContext &Ctx,
+                                              llvm::StringRef &Platform,
+                                              llvm::VersionTuple &PlatformVer);
 };
 
 /// Given a declaration upon which an availability attribute would appear in

include/swift/AST/PlatformKind.h

@@ -78,7 +78,7 @@ inline bool isApplicationExtensionPlatform(PlatformKind Platform) {
 /// triple will be used rather than the target to determine whether the
 /// platform is active.
 bool isPlatformActive(PlatformKind Platform, const LangOptions &LangOpts,
-                      bool ForTargetVariant = false);
+                      bool ForTargetVariant = false, bool ForRuntimeQuery = false);
 
 /// Returns the target platform for the given language options.
 PlatformKind targetPlatform(const LangOptions &LangOpts);

include/swift/AST/PlatformKinds.def

@@ -25,10 +25,12 @@
 AVAILABILITY_PLATFORM(iOS, "iOS")
 AVAILABILITY_PLATFORM(tvOS, "tvOS")
 AVAILABILITY_PLATFORM(watchOS, "watchOS")
+AVAILABILITY_PLATFORM(visionOS, "visionOS")
 AVAILABILITY_PLATFORM(macOS, "macOS")
 AVAILABILITY_PLATFORM(iOSApplicationExtension, "application extensions for iOS")
 AVAILABILITY_PLATFORM(tvOSApplicationExtension, "application extensions for tvOS")
 AVAILABILITY_PLATFORM(watchOSApplicationExtension, "application extensions for watchOS")
+AVAILABILITY_PLATFORM(visionOSApplicationExtension, "application extensions for visionOS")
 AVAILABILITY_PLATFORM(macOSApplicationExtension, "application extensions for macOS")
 AVAILABILITY_PLATFORM(macCatalyst, "Mac Catalyst")
 AVAILABILITY_PLATFORM(macCatalystApplicationExtension, "application extensions for Mac Catalyst")

include/swift/AST/RuntimeVersions.def

@@ -135,6 +135,7 @@ RUNTIME_VERSION(
   PLATFORM(macOS,   (14, 4, 0))
   PLATFORM(iOS,     (17, 4, 0))
   PLATFORM(watchOS, (10, 4, 0))
+  PLATFORM(xrOS, (1, 0, 0))
 )
 
 RUNTIME_VERSION(

include/swift/AST/SearchPathOptions.h

@@ -500,6 +500,10 @@ class SearchPathOptions {
   /// A file containing a list of protocols whose conformances require const value extraction.
   std::string ConstGatherProtocolListFilePath;
 
+  /// Path to the file that defines platform mapping for availability
+  /// version inheritance.
+  std::optional<std::string> PlatformAvailabilityInheritanceMapPath;
+
   /// Debug path mappings to apply to serialized search paths. These are
   /// specified in LLDB from the target.source-map entries.
   PathRemapper SearchPathRemapper;

include/swift/Basic/LangOptions.h

@@ -635,6 +635,8 @@ namespace swift {
         return Target.getiOSVersion();
       } else if (Target.isWatchOS()) {
         return Target.getOSVersion();
+      } else if (Target.isXROS()) {
+        return Target.getOSVersion();
       }
       return llvm::VersionTuple(/*Major=*/0, /*Minor=*/0, /*Subminor=*/0);
     }

include/swift/Basic/Platform.h

@@ -33,7 +33,9 @@ namespace swift {
     TvOS,
     TvOSSimulator,
     WatchOS,
-    WatchOSSimulator
+    WatchOSSimulator,
+    VisionOS,
+    VisionOSSimulator
   };
 
   /// Returns true if the given triple represents iOS running in a simulator.
@@ -48,6 +50,9 @@ namespace swift {
   /// Returns true if the given triple represents a macCatalyst environment.
   bool tripleIsMacCatalystEnvironment(const llvm::Triple &triple);
 
+  /// Returns true if the given triple represents visionOS running in a simulator.
+  bool tripleIsVisionSimulator(const llvm::Triple &triple);
+
   /// Determine whether the triple infers the "simulator" environment.
   bool tripleInfersSimulatorEnvironment(const llvm::Triple &triple);
 

include/swift/Frontend/Frontend.h

@@ -233,6 +233,8 @@ class CompilerInvocation {
 
   void setRuntimeResourcePath(StringRef Path);
 
+  void setPlatformAvailabilityInheritanceMapPath(StringRef Path);
+
   /// Compute the default prebuilt module cache path for a given resource path
   /// and SDK version. This function is also used by LLDB.
   static std::string

include/swift/Option/FrontendOptions.td

@@ -1343,4 +1343,8 @@ def module_load_mode: Separate<["-"], "module-load-mode">,
     MetaVarName<"only-interface|prefer-interface|prefer-serialized|only-serialized">,
     HelpText<"Module loading mode">;
 
+def platform_availability_inheritance_map_path
+  : Separate<["-"], "platform-availability-inheritance-map-path">, MetaVarName<"<path>">,
+    HelpText<"Path of the platform inheritance platform map">;
+
 } // end let Flags = [FrontendOption, NoDriverOption, HelpHidden]

include/swift/RemoteInspection/RuntimeHeaders/llvm/BinaryFormat/MachO.h

@@ -508,6 +508,8 @@ enum PlatformType {
   PLATFORM_TVOSSIMULATOR = 8,
   PLATFORM_WATCHOSSIMULATOR = 9,
   PLATFORM_DRIVERKIT = 10,
+  PLATFORM_XROS = 11,
+  PLATFORM_XROS_SIMULATOR = 12
 };
 
 // Values for tools enum in build_tool_version.

lib/AST/ASTContext.cpp

@@ -657,6 +657,8 @@ struct ASTContext::Implementation {
   /// The scratch context used to allocate intrinsic data on behalf of \c swift::IntrinsicInfo
   std::unique_ptr<llvm::LLVMContext> IntrinsicScratchContext;
 
+  mutable std::optional<std::unique_ptr<clang::DarwinSDKInfo>> SDKInfo;
+
   /// Memory allocation arena for the term rewriting system.
   std::unique_ptr<rewriting::RewriteContext> TheRewriteContext;
 
@@ -6399,6 +6401,44 @@ bool ASTContext::isASCIIString(StringRef s) const {
   return true;
 }
 
+clang::DarwinSDKInfo *ASTContext::getDarwinSDKInfo() const {
+  if (!getImpl().SDKInfo) {
+    auto SDKInfoOrErr = clang::parseDarwinSDKInfo(
+            *llvm::vfs::getRealFileSystem(),
+            SearchPathOpts.SDKPath);
+    if (!SDKInfoOrErr) {
+      llvm::handleAllErrors(SDKInfoOrErr.takeError(),
+                            [](const llvm::ErrorInfoBase &) {
+                              // Ignore the error for now..
+                            });
+      getImpl().SDKInfo.emplace();
+    } else if (!*SDKInfoOrErr) {
+      getImpl().SDKInfo.emplace();
+    } else {
+      getImpl().SDKInfo.emplace(std::make_unique<clang::DarwinSDKInfo>(**SDKInfoOrErr));
+    }
+  }
+
+  return getImpl().SDKInfo->get();
+}
+
+const clang::DarwinSDKInfo::RelatedTargetVersionMapping
+*ASTContext::getAuxiliaryDarwinPlatformRemapInfo(clang::DarwinSDKInfo::OSEnvPair Kind) const {
+  if (SearchPathOpts.PlatformAvailabilityInheritanceMapPath) {
+    auto SDKInfoOrErr = clang::parseDarwinSDKInfo(
+            *llvm::vfs::getRealFileSystem(),
+            *SearchPathOpts.PlatformAvailabilityInheritanceMapPath);
+    if (!SDKInfoOrErr || !*SDKInfoOrErr) {
+      llvm::handleAllErrors(SDKInfoOrErr.takeError(),
+                            [](const llvm::ErrorInfoBase &) {
+        // Ignore the error for now..
+      });
+    }
+    return (*SDKInfoOrErr)->getVersionMapping(Kind);
+  }
+  return nullptr;
+}
+
 /// The special Builtin.TheTupleType, which parents tuple extensions and
 /// conformances.
 BuiltinTupleDecl *ASTContext::getBuiltinTupleDecl() {

lib/AST/Attr.cpp

@@ -497,6 +497,13 @@ DeclAttributes::getDeprecated(const ASTContext &ctx) const {
         return AvAttr;
 
       std::optional<llvm::VersionTuple> DeprecatedVersion = AvAttr->Deprecated;
+
+      StringRef DeprecatedPlatform = AvAttr->prettyPlatformString();
+      llvm::VersionTuple RemappedDeprecatedVersion;
+      if (AvailabilityInference::updateDeprecatedPlatformForFallback(
+          AvAttr, ctx, DeprecatedPlatform, RemappedDeprecatedVersion))
+        DeprecatedVersion = RemappedDeprecatedVersion;
+
       if (!DeprecatedVersion.has_value())
         continue;
 
@@ -2335,18 +2342,32 @@ AvailableVersionComparison AvailableAttr::getVersionAvailability(
     return AvailableVersionComparison::Unavailable;
 
   llvm::VersionTuple queryVersion = getActiveVersion(ctx);
+  std::optional<llvm::VersionTuple> ObsoletedVersion = Obsoleted;
+
+  StringRef ObsoletedPlatform = prettyPlatformString();
+  llvm::VersionTuple RemappedObsoletedVersion;
+  if (AvailabilityInference::updateObsoletedPlatformForFallback(
+      this, ctx, ObsoletedPlatform, RemappedObsoletedVersion))
+    ObsoletedVersion = RemappedObsoletedVersion;
 
   // If this entity was obsoleted before or at the query platform version,
   // consider it obsolete.
-  if (Obsoleted && *Obsoleted <= queryVersion)
+  if (ObsoletedVersion && *ObsoletedVersion <= queryVersion)
     return AvailableVersionComparison::Obsoleted;
 
+  std::optional<llvm::VersionTuple> IntroducedVersion = Introduced;
+  StringRef IntroducedPlatform = prettyPlatformString();
+  llvm::VersionTuple RemappedIntroducedVersion;
+  if (AvailabilityInference::updateIntroducedPlatformForFallback(
+      this, ctx, IntroducedPlatform, RemappedIntroducedVersion))
+    IntroducedVersion = RemappedIntroducedVersion;
+
   // If this entity was introduced after the query version and we're doing a
   // platform comparison, true availability can only be determined dynamically;
   // if we're doing a _language_ version check, the query version is a
   // static requirement, so we treat "introduced later" as just plain
   // unavailable.
-  if (Introduced && *Introduced > queryVersion) {
+  if (IntroducedVersion && *IntroducedVersion > queryVersion) {
     if (isLanguageVersionSpecific() || isPackageDescriptionVersionSpecific())
       return AvailableVersionComparison::Unavailable;
     else