diff --git a/include/swift/AST/ASTContext.h b/include/swift/AST/ASTContext.h
index b2e04578de7f8..22f7a49ccb347 100644
--- a/include/swift/AST/ASTContext.h
+++ b/include/swift/AST/ASTContext.h
@@ -23,18 +23,12 @@
 #include "swift/AST/Identifier.h"
 #include "swift/AST/Import.h"
 #include "swift/AST/ProtocolConformanceOptions.h"
-#include "swift/AST/SILOptions.h"
-#include "swift/AST/SearchPathOptions.h"
 #include "swift/AST/Type.h"
 #include "swift/AST/TypeAlignments.h"
 #include "swift/AST/Types.h"
 #include "swift/Basic/BlockList.h"
-#include "swift/Basic/CASOptions.h"
-#include "swift/Basic/LangOptions.h"
 #include "swift/Basic/Located.h"
 #include "swift/Basic/Malloc.h"
-#include "swift/Serialization/SerializationOptions.h"
-#include "swift/SymbolGraphGen/SymbolGraphOptions.h"
 #include "clang/AST/DeclTemplate.h"
 #include "clang/Basic/DarwinSDKInfo.h"
 #include "llvm/ADT/ArrayRef.h"
@@ -77,6 +71,7 @@ namespace swift {
   class AvailabilityRange;
   class BoundGenericType;
   class BuiltinTupleDecl;
+  class CASOptions;
   class ClangModuleLoader;
   class ClangNode;
   class ClangTypeConverter;
@@ -100,6 +95,7 @@ namespace swift {
   class LazyContextData;
   class LazyIterableDeclContextData;
   class LazyMemberLoader;
+  class LangOptions;
   struct MacroDiscriminatorContext;
   class ModuleInterfaceChecker;
   class PatternBindingDecl;
@@ -107,13 +103,14 @@ namespace swift {
   class PluginLoader;
   class SourceFile;
   class SourceLoc;
+  class SerializationOptions;
+  class SILOptions;
   struct TemplateInstantiationError;
   class Type;
   class TypeVariableType;
   class TupleType;
   class FunctionType;
   class ArchetypeType;
-  class Identifier;
   class InheritedNameSet;
   class ModuleDecl;
   class PackageUnit;
@@ -142,6 +139,7 @@ namespace swift {
   class DiagnosticEngine;
   struct RawComment;
   class DocComment;
+  class SearchPathOptions;
   class SILBoxType;
   class SILTransform;
   class TypeAliasDecl;
@@ -165,6 +163,10 @@ namespace ide {
   class TypeCheckCompletionCallback;
 }
 
+namespace symbolgraphgen {
+  struct SymbolGraphOptions;
+}
+
 /// Lists the set of "known" Foundation entities that are used in the
 /// compiler.
 ///
diff --git a/include/swift/AST/PlatformKindUtils.h b/include/swift/AST/PlatformKindUtils.h
index e0f3f240a0e9e..763e342c3988a 100644
--- a/include/swift/AST/PlatformKindUtils.h
+++ b/include/swift/AST/PlatformKindUtils.h
@@ -80,6 +80,10 @@ PlatformKind targetPlatform(const LangOptions &LangOpts);
 /// Returns the target variant platform for the given language options.
 PlatformKind targetVariantPlatform(const LangOptions &LangOpts);
 
+/// Returns the target platform for the given triple and options.
+PlatformKind platformForTriple(const llvm::Triple &triple,
+                               bool enableAppExtensionRestrictions);
+
 /// Returns true when availability attributes from the "parent" platform
 /// should also apply to the "child" platform for declarations without
 /// an explicit attribute for the child.
diff --git a/include/swift/Option/Options.td b/include/swift/Option/Options.td
index b9f1217230dc2..e330d2ff87fab 100644
--- a/include/swift/Option/Options.td
+++ b/include/swift/Option/Options.td
@@ -1939,6 +1939,12 @@ def block_availability_platforms: Separate<["-"], "block-availability-platforms"
   HelpText<"Remove the given platforms from symbol graph availability metadata, e.g. 'macOS,Swift'">,
   MetaVarName<"<platforms>">;
 
+def active_platform_availability_only
+    : Flag<["-"], "active-platform-availability-only">,
+      Flags<[SwiftSymbolGraphExtractOption]>,
+      HelpText<"Only emit availability metadata for platforms that are active "
+               "according to the target">;
+
 // swift-synthesize-interface-only options
 def include_submodules : Flag<["-"], "include-submodules">,
   Flags<[NoDriverOption, SwiftSynthesizeInterfaceOption]>,
diff --git a/include/swift/SymbolGraphGen/SymbolGraphOptions.h b/include/swift/SymbolGraphGen/SymbolGraphOptions.h
index 3b43314dc9dba..82d859cb7f2b2 100644
--- a/include/swift/SymbolGraphGen/SymbolGraphOptions.h
+++ b/include/swift/SymbolGraphGen/SymbolGraphOptions.h
@@ -10,6 +10,7 @@
 //
 //===----------------------------------------------------------------------===//
 
+#include "swift/AST/PlatformKind.h"
 #include "llvm/ADT/ArrayRef.h"
 #include "llvm/ADT/DenseSet.h"
 #include "llvm/TargetParser/Triple.h"
@@ -78,6 +79,9 @@ struct SymbolGraphOptions {
   /// Whether `AvailabilityPlatforms` is an allow list or a block list.
   bool AvailabilityIsBlockList = false;
 
+  /// If non-null, only emit availability metadata for the active platform.
+  std::optional<PlatformKind> ActivePlatform = std::nullopt;
+
   /// Whether to use shortened, by using a hash of the module names, file names
   /// when writing symbol graph files to `OutputDir`.
   /// An additional JSON file is written at `OutputDir` that contains a mapping
diff --git a/lib/AST/Module.cpp b/lib/AST/Module.cpp
index adf39d5aec6b0..768e9c6e99fd0 100644
--- a/lib/AST/Module.cpp
+++ b/lib/AST/Module.cpp
@@ -40,6 +40,7 @@
 #include "swift/AST/PrettyStackTrace.h"
 #include "swift/AST/PrintOptions.h"
 #include "swift/AST/ProtocolConformance.h"
+#include "swift/AST/SearchPathOptions.h"
 #include "swift/AST/SourceFile.h"
 #include "swift/AST/SourceFileExtras.h"
 #include "swift/AST/SynthesizedFileUnit.h"
diff --git a/lib/AST/PlatformKindUtils.cpp b/lib/AST/PlatformKindUtils.cpp
index 1b56a5968f1e3..f4a3454ed3b9e 100644
--- a/lib/AST/PlatformKindUtils.cpp
+++ b/lib/AST/PlatformKindUtils.cpp
@@ -194,7 +194,7 @@ bool swift::isPlatformActive(PlatformKind Platform, const LangOptions &LangOpts,
                                    ForRuntimeQuery);
 }
 
-static PlatformKind platformForTriple(const llvm::Triple &triple,
+PlatformKind swift::platformForTriple(const llvm::Triple &triple,
                                       bool enableAppExtensionRestrictions) {
   if (triple.isMacOSX()) {
     return (enableAppExtensionRestrictions
diff --git a/lib/AST/PluginLoader.cpp b/lib/AST/PluginLoader.cpp
index 571ab68df061a..46617ad685fa1 100644
--- a/lib/AST/PluginLoader.cpp
+++ b/lib/AST/PluginLoader.cpp
@@ -14,7 +14,9 @@
 #include "swift/AST/ASTContext.h"
 #include "swift/AST/DiagnosticEngine.h"
 #include "swift/AST/DiagnosticsSema.h"
+#include "swift/AST/SearchPathOptions.h"
 #include "swift/Basic/Assertions.h"
+#include "swift/Basic/CASOptions.h"
 #include "swift/Basic/SourceManager.h"
 #include "swift/Parse/Lexer.h"
 #include "llvm/Config/config.h"
diff --git a/lib/ClangImporter/ClangIncludePaths.cpp b/lib/ClangImporter/ClangIncludePaths.cpp
index 832fb388b3d46..5bc725811f7c6 100644
--- a/lib/ClangImporter/ClangIncludePaths.cpp
+++ b/lib/ClangImporter/ClangIncludePaths.cpp
@@ -14,6 +14,7 @@
 #include "swift/AST/ASTContext.h"
 #include "swift/AST/DiagnosticEngine.h"
 #include "swift/AST/DiagnosticsClangImporter.h"
+#include "swift/AST/SearchPathOptions.h"
 #include "swift/Basic/Assertions.h"
 #include "swift/Basic/Platform.h"
 #include "swift/ClangImporter/ClangImporter.h"
diff --git a/lib/ClangImporter/ClangModuleDependencyScanner.cpp b/lib/ClangImporter/ClangModuleDependencyScanner.cpp
index e4258b31bed3c..b0a3ebd1a0af0 100644
--- a/lib/ClangImporter/ClangModuleDependencyScanner.cpp
+++ b/lib/ClangImporter/ClangModuleDependencyScanner.cpp
@@ -16,9 +16,10 @@
 #include "ImporterImpl.h"
 #include "swift/AST/DiagnosticsSema.h"
 #include "swift/AST/ModuleDependencies.h"
+#include "swift/Basic/Assertions.h"
+#include "swift/Basic/CASOptions.h"
 #include "swift/Basic/SourceManager.h"
 #include "swift/ClangImporter/ClangImporter.h"
-#include "swift/Basic/Assertions.h"
 #include "clang/Basic/Diagnostic.h"
 #include "clang/CAS/CASOptions.h"
 #include "clang/Frontend/CompilerInvocation.h"
@@ -28,8 +29,8 @@
 #include "llvm/ADT/STLExtras.h"
 #include "llvm/Support/Allocator.h"
 #include "llvm/Support/FileSystem.h"
-#include "llvm/Support/Signals.h"
 #include "llvm/Support/Path.h"
+#include "llvm/Support/Signals.h"
 #include "llvm/Support/StringSaver.h"
 
 using namespace swift;
diff --git a/lib/ClangImporter/ImportDecl.cpp b/lib/ClangImporter/ImportDecl.cpp
index 82411b3b0cdc7..316d971314866 100644
--- a/lib/ClangImporter/ImportDecl.cpp
+++ b/lib/ClangImporter/ImportDecl.cpp
@@ -42,6 +42,7 @@
 #include "swift/AST/Pattern.h"
 #include "swift/AST/PrettyStackTrace.h"
 #include "swift/AST/ProtocolConformance.h"
+#include "swift/AST/SILOptions.h"
 #include "swift/AST/Stmt.h"
 #include "swift/AST/Type.h"
 #include "swift/AST/TypeCheckRequests.h"
diff --git a/lib/DriverTool/swift_symbolgraph_extract_main.cpp b/lib/DriverTool/swift_symbolgraph_extract_main.cpp
index 764458c18fcac..245987b59e1a2 100644
--- a/lib/DriverTool/swift_symbolgraph_extract_main.cpp
+++ b/lib/DriverTool/swift_symbolgraph_extract_main.cpp
@@ -190,6 +190,13 @@ int swift_symbolgraph_extract_main(ArrayRef<const char *> Args,
       ParsedArgs.hasFlag(OPT_emit_extension_block_symbols,
                          OPT_omit_extension_block_symbols, /*default=*/false);
   Options.AllowedReexportedModules = AllowedRexports;
+  if (ParsedArgs.hasArg(OPT_active_platform_availability_only)) {
+    // The output should only include platform availability that applies to the
+    // platform inferred from the -target. Include app extension availability,
+    // too.
+    Options.ActivePlatform =
+        platformForTriple(Target, /*enableAppExtensionRestrictions=*/true);
+  }
 
   if (auto *A = ParsedArgs.getLastArg(OPT_minimum_access_level)) {
     Options.MinimumAccessLevel =
diff --git a/lib/IRGen/GenType.cpp b/lib/IRGen/GenType.cpp
index f49329384add1..8b2acc1d3f6bc 100644
--- a/lib/IRGen/GenType.cpp
+++ b/lib/IRGen/GenType.cpp
@@ -21,6 +21,7 @@
 #include "swift/AST/LazyResolver.h"
 #include "swift/AST/IRGenOptions.h"
 #include "swift/AST/PrettyStackTrace.h"
+#include "swift/AST/SearchPathOptions.h"
 #include "swift/AST/Types.h"
 #include "swift/Basic/Assertions.h"
 #include "swift/Basic/Platform.h"
diff --git a/lib/Sema/ConstraintSystem.cpp b/lib/Sema/ConstraintSystem.cpp
index 276cece1a0087..67cc043cdb0e9 100644
--- a/lib/Sema/ConstraintSystem.cpp
+++ b/lib/Sema/ConstraintSystem.cpp
@@ -31,6 +31,7 @@
 #include "swift/AST/MacroDefinition.h"
 #include "swift/AST/ParameterList.h"
 #include "swift/AST/ProtocolConformance.h"
+#include "swift/AST/SILOptions.h"
 #include "swift/AST/TypeCheckRequests.h"
 #include "swift/AST/TypeTransform.h"
 #include "swift/AST/Types.h"
diff --git a/lib/SymbolGraphGen/AvailabilityMixin.cpp b/lib/SymbolGraphGen/AvailabilityMixin.cpp
index 75a1c150e409b..ce8f6b8ec28a9 100644
--- a/lib/SymbolGraphGen/AvailabilityMixin.cpp
+++ b/lib/SymbolGraphGen/AvailabilityMixin.cpp
@@ -17,19 +17,18 @@
 using namespace swift;
 using namespace symbolgraphgen;
 
-namespace {
-StringRef getDomain(const SemanticAvailableAttr &AvAttr) {
+StringRef Availability::getDomainDescription(AvailabilityDomain Domain) {
   // FIXME: [avalailability] Move the definition of these strings into
   // AvailabilityDomain so that new domains are handled automatically.
 
-  if (AvAttr.getDomain().isPackageDescription())
+  if (Domain.isPackageDescription())
     return { "SwiftPM" };
 
-  if (AvAttr.getDomain().isSwiftLanguageMode())
+  if (Domain.isSwiftLanguageMode())
     return { "Swift" };
 
   // Platform-specific availability.
-  switch (AvAttr.getPlatform()) {
+  switch (Domain.getPlatformKind()) {
     case swift::PlatformKind::iOS:
       return { "iOS" };
     case swift::PlatformKind::macCatalyst:
@@ -73,12 +72,12 @@ StringRef getDomain(const SemanticAvailableAttr &AvAttr) {
   }
   llvm_unreachable("invalid platform kind");
 }
-} // end anonymous namespace
 
 Availability::Availability(const SemanticAvailableAttr &AvAttr)
-    : Domain(getDomain(AvAttr)), Introduced(AvAttr.getIntroduced()),
-      Deprecated(AvAttr.getDeprecated()), Obsoleted(AvAttr.getObsoleted()),
-      Message(AvAttr.getMessage()), Renamed(AvAttr.getRename()),
+    : Domain(getDomainDescription(AvAttr.getDomain())),
+      Introduced(AvAttr.getIntroduced()), Deprecated(AvAttr.getDeprecated()),
+      Obsoleted(AvAttr.getObsoleted()), Message(AvAttr.getMessage()),
+      Renamed(AvAttr.getRename()),
       IsUnconditionallyDeprecated(AvAttr.isUnconditionallyDeprecated()),
       IsUnconditionallyUnavailable(AvAttr.isUnconditionallyUnavailable()) {
   assert(!Domain.empty());
diff --git a/lib/SymbolGraphGen/AvailabilityMixin.h b/lib/SymbolGraphGen/AvailabilityMixin.h
index 39fc82f007911..e66f8dea1da0c 100644
--- a/lib/SymbolGraphGen/AvailabilityMixin.h
+++ b/lib/SymbolGraphGen/AvailabilityMixin.h
@@ -49,6 +49,8 @@ struct Availability {
   /// If \c true, is unconditionally unavailable in this \c Domain.
   bool IsUnconditionallyUnavailable;
 
+  static StringRef getDomainDescription(AvailabilityDomain Domain);
+
   Availability(const SemanticAvailableAttr &AvAttr);
 
   /// Update this availability from a duplicate @available
diff --git a/lib/SymbolGraphGen/Symbol.cpp b/lib/SymbolGraphGen/Symbol.cpp
index f5faae6d87801..6afb05f550af4 100644
--- a/lib/SymbolGraphGen/Symbol.cpp
+++ b/lib/SymbolGraphGen/Symbol.cpp
@@ -639,6 +639,94 @@ void Symbol::serializeLocationMixin(llvm::json::OStream &OS) const {
 }
 
 namespace {
+/// Insert or merge a single Availability entry into a domain map, using
+/// either parent-inheritance or duplicate-attribute rules.
+void insertAvailability(Availability NewAvailability,
+                        llvm::StringMap<Availability> &Availabilities,
+                        bool IsParent) {
+  if (NewAvailability.empty())
+    return;
+  auto Existing = Availabilities.find(NewAvailability.Domain);
+  if (Existing != Availabilities.end()) {
+    // There are different rules for filling in missing components or replacing
+    // existing components from a parent's @available attribute compared to
+    // duplicate @available attributes on the same declaration. See the
+    // respective methods below for an explanation for the replacement/filling
+    // rules.
+    // FIXME: [availability] Use compiler's logic to synthesize availability.
+    // Some of this merge logic is out-of-sync with how the compiler determines
+    // availability when multiple attributes apply to the same platform.
+    if (IsParent) {
+      Existing->getValue().updateFromParent(NewAvailability);
+    } else {
+      Existing->getValue().updateFromDuplicate(NewAvailability);
+    }
+  } else {
+    // There are no availabilities for this domain yet, so either inherit the
+    // parent's in its entirety or set it from this declaration.
+    Availabilities.insert({NewAvailability.Domain, NewAvailability});
+  }
+}
+
+std::optional<ArrayRef<PlatformKind>>
+getPlatformsToExpand(SemanticAvailableAttr AvAttr) {
+  // For now, only expand platform availability for anyAppleOS attributes.
+  if (AvAttr.getDomain().contains(
+          AvailabilityDomain::forPlatform(PlatformKind::anyAppleOS))) {
+    static const PlatformKind ApplePlatforms[] = {
+      PlatformKind::macOS,
+      PlatformKind::iOS,
+      PlatformKind::watchOS,
+      PlatformKind::tvOS,
+      PlatformKind::visionOS,
+    };
+    return ApplePlatforms;
+  }
+
+  return {};
+}
+
+static bool
+isAvailabilityDomainActive(AvailabilityDomain Domain,
+                           std::optional<PlatformKind> ActivePlatform) {
+  if (!ActivePlatform)
+    return true;
+
+  if (!Domain.isPlatform())
+    return true;
+
+  auto Platform = Domain.getPlatformKind();
+  return Platform == *ActivePlatform ||
+         inheritsAvailabilityFromPlatform(*ActivePlatform, Platform);
+}
+
+/// Expands a single availability attribute into one or more Availability
+/// structs.
+void expandInferredAvailabilityAttr(
+    SemanticAvailableAttr AvAttr, SmallVectorImpl<Availability> &Expanded,
+    std::optional<PlatformKind> ActivePlatform) {
+  if (auto Platforms = getPlatformsToExpand(AvAttr)) {
+    for (auto Platform : *Platforms) {
+      auto PlatformDomain = AvailabilityDomain::forPlatform(Platform);
+      if (!isAvailabilityDomainActive(PlatformDomain, ActivePlatform))
+        continue;
+
+      Availability InferredAvailability(AvAttr);
+      InferredAvailability.Domain =
+          Availability::getDomainDescription(PlatformDomain);
+      // FIXME: [availability] Versions should be remapped, too.
+      // Version remapping is unnecessary at the moment because only anyAppleOS
+      // availability gets expanded and anyAppleOS doesn't require version
+      // remapping (yet).
+      Expanded.push_back(InferredAvailability);
+    }
+    return;
+  }
+
+  // Just convert the attribute directly.
+  Expanded.push_back(Availability(AvAttr));
+}
+
 /// Get the availabilities for each domain on a declaration without walking
 /// up the parent hierarchy.
 ///
@@ -649,48 +737,35 @@ namespace {
 /// duplicate \c \@available attributes on the same declaration.
 void getAvailabilities(const Decl *D,
                        llvm::StringMap<Availability> &Availabilities,
-                       bool IsParent) {
+                       bool IsParent,
+                       std::optional<PlatformKind> ActivePlatform) {
   // DeclAttributes is a linked list in reverse order from where they
   // appeared in the source. Let's re-reverse them.
-  SmallVector<SemanticAvailableAttr, 4> AvAttrs;
-  for (auto Attr : D->getSemanticAvailableAttrs(/*includeInactive=*/true)) {
+  SmallVector<SemanticAvailableAttr, 8> AvAttrs;
+  for (auto Attr : D->getSemanticAvailableAttrs(/*includingInactive=*/true)) {
+    if (!isAvailabilityDomainActive(Attr.getDomain(), ActivePlatform))
+      continue;
+
     AvAttrs.push_back(Attr);
   }
-  std::reverse(AvAttrs.begin(), AvAttrs.end());
 
   // Now go through them in source order.
-  for (auto AvAttr : AvAttrs) {
-    Availability NewAvailability(AvAttr);
-    if (NewAvailability.empty()) {
-      continue;
-    }
-    auto ExistingAvailability = Availabilities.find(NewAvailability.Domain);
-    if (ExistingAvailability != Availabilities.end()) {
-      // There are different rules for filling in missing components
-      // or replacing existing components from a parent's @available
-      // attribute compared to duplicate @available attributes on the
-      // same declaration.
-      // See the respective methods below for an explanation for the
-      // replacement/filling rules.
-      if (IsParent) {
-        ExistingAvailability->getValue().updateFromParent(NewAvailability);
-      } else {
-        ExistingAvailability->getValue().updateFromDuplicate(NewAvailability);
-      }
-    } else {
-      // There are no availabilities for this domain yet, so either
-      // inherit the parent's in its entirety or set it from this declaration.
-      Availabilities.insert(std::make_pair(NewAvailability.Domain,
-                                           NewAvailability));
-    }
+  for (auto AvAttr : llvm::reverse(AvAttrs)) {
+    SmallVector<Availability, 5> ExpandedAvailabilities;
+    expandInferredAvailabilityAttr(AvAttr, ExpandedAvailabilities,
+                                   ActivePlatform);
+    for (auto &Avail : ExpandedAvailabilities)
+      insertAvailability(Avail, Availabilities, IsParent);
   }
 }
 
-/// Get the availabilities of a declaration, considering all of its
-/// parent context's except for the module.
+/// Get the availabilities of a declaration, considering all of its parent
+/// context's except for the module. If \p ActivePlatform is non-null, only
+/// include availability relevant to the active platform.
 void getInheritedAvailabilities(const Decl *D,
-llvm::StringMap<Availability> &Availabilities) {
-  getAvailabilities(D, Availabilities, /*IsParent*/false);
+                                llvm::StringMap<Availability> &Availabilities,
+                                std::optional<PlatformKind> ActivePlatform) {
+  getAvailabilities(D, Availabilities, /*IsParent*/ false, ActivePlatform);
 
   auto CurrentContext = D->getDeclContext();
   while (CurrentContext) {
@@ -698,7 +773,8 @@ llvm::StringMap<Availability> &Availabilities) {
       if (isa<ModuleDecl>(Parent)) {
         return;
       }
-      getAvailabilities(Parent, Availabilities, /*IsParent*/true);
+      getAvailabilities(Parent, Availabilities, /*IsParent*/ true,
+                        ActivePlatform);
     }
     CurrentContext = CurrentContext->getParent();
   }
@@ -708,7 +784,8 @@ llvm::StringMap<Availability> &Availabilities) {
 
 void Symbol::serializeAvailabilityMixin(llvm::json::OStream &OS) const {
   llvm::StringMap<Availability> Availabilities;
-  getInheritedAvailabilities(D, Availabilities);
+  getInheritedAvailabilities(D, Availabilities,
+                             Graph->Walker.Options.ActivePlatform);
 
   // If we were asked to filter the availability platforms for the output graph,
   // perform that filtering here.
@@ -734,10 +811,18 @@ void Symbol::serializeAvailabilityMixin(llvm::json::OStream &OS) const {
     return;
   }
 
-  OS.attributeArray("availability", [&]{
-    for (const auto &Availability : Availabilities) {
-      Availability.getValue().serialize(OS);
-    }
+  OS.attributeArray("availability", [&] {
+    // Sort the availability entries to ensure that they are emitted in a stable
+    // order.
+    SmallVector<Availability, 8> SortedAvailabilities;
+    for (const auto &A : Availabilities)
+      SortedAvailabilities.push_back(A.getValue());
+    llvm::sort(SortedAvailabilities,
+               [](const Availability &A, const Availability &B) {
+                 return A.Domain < B.Domain;
+               });
+    for (const auto &A : SortedAvailabilities)
+      A.serialize(OS);
   });
 }
 
diff --git a/test/SymbolGraph/Symbols/Mixins/Availability/AnyAppleOS/Expansion.swift b/test/SymbolGraph/Symbols/Mixins/Availability/AnyAppleOS/Expansion.swift
new file mode 100644
index 0000000000000..168f0ed035dac
--- /dev/null
+++ b/test/SymbolGraph/Symbols/Mixins/Availability/AnyAppleOS/Expansion.swift
@@ -0,0 +1,93 @@
+// RUN: %empty-directory(%t)
+// RUN: %target-build-swift %s -module-name Expansion -emit-module -emit-module-path %t/
+// RUN: %target-swift-symbolgraph-extract -module-name Expansion -I %t -pretty-print -output-dir %t
+// RUN: %FileCheck %s --input-file %t/Expansion.symbols.json
+
+// CHECK-LABEL: "symbols": [
+// CHECK-LABEL: "precise": "s:9Expansion1SV",
+// CHECK: "availability": [
+// CHECK-NEXT: {
+// CHECK-NEXT: "domain": "iOS",
+// CHECK-NEXT: "introduced": {
+// CHECK-NEXT: "major": 26
+// CHECK-NEXT: },
+// CHECK-NEXT: "deprecated": {
+// CHECK-NEXT: "major": 26,
+// CHECK-NEXT: "minor": 2
+// CHECK-NEXT: },
+// CHECK-NEXT: "obsoleted": {
+// CHECK-NEXT: "major": 26,
+// CHECK-NEXT: "minor": 4
+// CHECK-NEXT: },
+// CHECK-NEXT: "message": "Everyone makes mistakes",
+// CHECK-NEXT: "renamed": "S2"
+// CHECK-NEXT: },
+// CHECK-NEXT: {
+// CHECK-NEXT: "domain": "macOS",
+// CHECK-NEXT: "introduced": {
+// CHECK-NEXT: "major": 26
+// CHECK-NEXT: },
+// CHECK-NEXT: "deprecated": {
+// CHECK-NEXT: "major": 26,
+// CHECK-NEXT: "minor": 2
+// CHECK-NEXT: },
+// CHECK-NEXT: "obsoleted": {
+// CHECK-NEXT: "major": 26,
+// CHECK-NEXT: "minor": 4
+// CHECK-NEXT: },
+// CHECK-NEXT: "message": "Everyone makes mistakes",
+// CHECK-NEXT: "renamed": "S2"
+// CHECK-NEXT: },
+// CHECK-NEXT: {
+// CHECK-NEXT: "domain": "tvOS",
+// CHECK-NEXT: "introduced": {
+// CHECK-NEXT: "major": 26
+// CHECK-NEXT: },
+// CHECK-NEXT: "deprecated": {
+// CHECK-NEXT: "major": 26,
+// CHECK-NEXT: "minor": 2
+// CHECK-NEXT: },
+// CHECK-NEXT: "obsoleted": {
+// CHECK-NEXT: "major": 26,
+// CHECK-NEXT: "minor": 4
+// CHECK-NEXT: },
+// CHECK-NEXT: "message": "Everyone makes mistakes",
+// CHECK-NEXT: "renamed": "S2"
+// CHECK-NEXT: },
+// CHECK-NEXT: {
+// CHECK-NEXT: "domain": "visionOS",
+// CHECK-NEXT: "introduced": {
+// CHECK-NEXT: "major": 26
+// CHECK-NEXT: },
+// CHECK-NEXT: "deprecated": {
+// CHECK-NEXT: "major": 26,
+// CHECK-NEXT: "minor": 2
+// CHECK-NEXT: },
+// CHECK-NEXT: "obsoleted": {
+// CHECK-NEXT: "major": 26,
+// CHECK-NEXT: "minor": 4
+// CHECK-NEXT: },
+// CHECK-NEXT: "message": "Everyone makes mistakes",
+// CHECK-NEXT: "renamed": "S2"
+// CHECK-NEXT: },
+// CHECK-NEXT: {
+// CHECK-NEXT: "domain": "watchOS",
+// CHECK-NEXT: "introduced": {
+// CHECK-NEXT: "major": 26
+// CHECK-NEXT: },
+// CHECK-NEXT: "deprecated": {
+// CHECK-NEXT: "major": 26,
+// CHECK-NEXT: "minor": 2
+// CHECK-NEXT: },
+// CHECK-NEXT: "obsoleted": {
+// CHECK-NEXT: "major": 26,
+// CHECK-NEXT: "minor": 4
+// CHECK-NEXT: },
+// CHECK-NEXT: "message": "Everyone makes mistakes",
+// CHECK-NEXT: "renamed": "S2"
+// CHECK-NEXT: }
+// CHECK-NEXT: ]
+// CHECK-NOT: "domain": "Any Apple OS"
+
+@available(anyAppleOS, introduced: 26, deprecated: 26.2, obsoleted: 26.4, message: "Everyone makes mistakes", renamed: "S2")
+public struct S {}
diff --git a/test/SymbolGraph/Symbols/Mixins/Availability/AnyAppleOS/InnerOverridesOuterPlatform.swift b/test/SymbolGraph/Symbols/Mixins/Availability/AnyAppleOS/InnerOverridesOuterPlatform.swift
new file mode 100644
index 0000000000000..077c5520dbb4f
--- /dev/null
+++ b/test/SymbolGraph/Symbols/Mixins/Availability/AnyAppleOS/InnerOverridesOuterPlatform.swift
@@ -0,0 +1,50 @@
+// RUN: %empty-directory(%t)
+// RUN: %target-build-swift %s -module-name InnerOverridesOuterPlatform -emit-module -emit-module-path %t/
+// RUN: %target-swift-symbolgraph-extract -module-name InnerOverridesOuterPlatform -I %t -pretty-print -output-dir %t
+// RUN: %FileCheck %s --input-file %t/InnerOverridesOuterPlatform.symbols.json
+
+// CHECK-LABEL: "symbols": [
+// CHECK-LABEL: "precise": "s:27InnerOverridesOuterPlatform0C0V0A0V",
+// CHECK: "availability": [
+// CHECK-NEXT: {
+// CHECK-NEXT: "domain": "iOS",
+// CHECK-NEXT: "introduced": {
+// CHECK-NEXT: "major": 26
+// CHECK-NEXT: "minor": 4
+// CHECK-NEXT: }
+// CHECK-NEXT: },
+// CHECK-NEXT: {
+// CHECK-NEXT: "domain": "macOS",
+// CHECK-NEXT: "introduced": {
+// CHECK-NEXT: "major": 26
+// CHECK-NEXT: "minor": 4
+// CHECK-NEXT: }
+// CHECK-NEXT: },
+// CHECK-NEXT: {
+// CHECK-NEXT: "domain": "tvOS",
+// CHECK-NEXT: "introduced": {
+// CHECK-NEXT: "major": 26
+// CHECK-NEXT: "minor": 4
+// CHECK-NEXT: }
+// CHECK-NEXT: },
+// CHECK-NEXT: {
+// CHECK-NEXT: "domain": "visionOS",
+// CHECK-NEXT: "introduced": {
+// CHECK-NEXT: "major": 26
+// CHECK-NEXT: "minor": 4
+// CHECK-NEXT: }
+// CHECK-NEXT: },
+// CHECK-NEXT: {
+// CHECK-NEXT: "domain": "watchOS",
+// CHECK-NEXT: "introduced": {
+// CHECK-NEXT: "major": 26
+// CHECK-NEXT: "minor": 4
+// CHECK-NEXT: }
+// CHECK-NEXT: }
+// CHECK-NEXT: ]
+
+@available(macOS 26, *)
+public struct Outer {
+  @available(anyAppleOS 26.4, *)
+  public struct Inner {}
+}
diff --git a/test/SymbolGraph/Symbols/Mixins/Availability/AnyAppleOS/InnerPlatformOverridesOuter.swift b/test/SymbolGraph/Symbols/Mixins/Availability/AnyAppleOS/InnerPlatformOverridesOuter.swift
new file mode 100644
index 0000000000000..d01bc24b8fb24
--- /dev/null
+++ b/test/SymbolGraph/Symbols/Mixins/Availability/AnyAppleOS/InnerPlatformOverridesOuter.swift
@@ -0,0 +1,56 @@
+// RUN: %empty-directory(%t)
+// RUN: %target-build-swift %s -module-name InnerPlatformOverridesOuter -emit-module -emit-module-path %t/
+// RUN: %target-swift-symbolgraph-extract -module-name InnerPlatformOverridesOuter -I %t -pretty-print -output-dir %t
+// RUN: %FileCheck %s --input-file %t/InnerPlatformOverridesOuter.symbols.json
+
+// CHECK-LABEL: "symbols": [
+// CHECK-LABEL: "precise": "s:27InnerPlatformOverridesOuter0D0V0A0V",
+// CHECK: "availability": [
+// CHECK-NEXT: {
+// CHECK-NEXT: "domain": "iOS",
+// CHECK-NEXT: "introduced": {
+// CHECK-NEXT: "major": 26,
+// CHECK-NEXT: "minor": 2
+// CHECK-NEXT: },
+// CHECK-NEXT: "obsoleted": {
+// CHECK-NEXT: "major": 26,
+// CHECK-NEXT: "minor": 4
+// CHECK-NEXT: }
+// CHECK-NEXT: },
+// CHECK-NEXT: {
+// CHECK-NEXT: "domain": "macOS",
+// CHECK-NEXT: "introduced": {
+// CHECK-NEXT: "major": 26
+// CHECK-NEXT: "minor": 4
+// CHECK-NEXT: }
+// CHECK-NEXT: },
+// CHECK-NEXT: {
+// CHECK-NEXT: "domain": "tvOS",
+// CHECK-NEXT: "introduced": {
+// CHECK-NEXT: "major": 26
+// CHECK-NEXT: },
+// CHECK-NEXT: "isUnconditionallyDeprecated": true
+// CHECK-NEXT: },
+// CHECK-NEXT: {
+// CHECK-NEXT: "domain": "visionOS",
+// CHECK-NEXT: "introduced": {
+// CHECK-NEXT: "major": 26
+// CHECK-NEXT: }
+// CHECK-NEXT: },
+// CHECK-NEXT: {
+// CHECK-NEXT: "domain": "watchOS",
+// CHECK-NEXT: "introduced": {
+// CHECK-NEXT: "major": 26,
+// CHECK-NEXT: "minor": 2
+// CHECK-NEXT: }
+// CHECK-NEXT: }
+// CHECK-NEXT: ]
+
+@available(anyAppleOS, introduced: 26)
+public struct Outer {
+  @available(macOS, introduced: 26.4)
+  @available(iOS, introduced: 26.2, obsoleted: 26.4)
+  @available(watchOS 26.2, *)
+  @available(tvOS, deprecated)
+  public struct Inner {}
+}
diff --git a/test/SymbolGraph/Symbols/Mixins/Availability/AnyAppleOS/OnlyActive.swift b/test/SymbolGraph/Symbols/Mixins/Availability/AnyAppleOS/OnlyActive.swift
new file mode 100644
index 0000000000000..f7471bba422dd
--- /dev/null
+++ b/test/SymbolGraph/Symbols/Mixins/Availability/AnyAppleOS/OnlyActive.swift
@@ -0,0 +1,20 @@
+// RUN: %empty-directory(%t)
+// RUN: %target-build-swift %s -module-name OnlyActive -emit-module -emit-module-path %t/
+// RUN: %target-swift-symbolgraph-extract -module-name OnlyActive -I %t -pretty-print -active-platform-availability-only -output-dir %t
+// RUN: %FileCheck %s --input-file %t/OnlyActive.symbols.json
+
+// REQUIRES: OS=macosx
+
+// CHECK-LABEL: "symbols": [
+// CHECK-LABEL: "precise": "s:10OnlyActive1SV",
+// CHECK: "availability": [
+// CHECK-NEXT: {
+// CHECK-NEXT: "domain": "macOS",
+// CHECK-NEXT: "introduced": {
+// CHECK-NEXT: "major": 26
+// CHECK-NEXT: }
+// CHECK-NEXT: }
+// CHECK-NEXT: ]
+
+@available(anyAppleOS 26, *)
+public struct S {}
diff --git a/test/SymbolGraph/Symbols/Mixins/Availability/AnyAppleOS/PlatformSupersedes.swift b/test/SymbolGraph/Symbols/Mixins/Availability/AnyAppleOS/PlatformSupersedes.swift
new file mode 100644
index 0000000000000..c6be6ced29d10
--- /dev/null
+++ b/test/SymbolGraph/Symbols/Mixins/Availability/AnyAppleOS/PlatformSupersedes.swift
@@ -0,0 +1,54 @@
+// RUN: %empty-directory(%t)
+// RUN: %target-build-swift %s -module-name PlatformSupersedes -emit-module -emit-module-path %t/
+// RUN: %target-swift-symbolgraph-extract -module-name PlatformSupersedes -I %t -pretty-print -output-dir %t
+// RUN: %FileCheck %s --input-file %t/PlatformSupersedes.symbols.json
+
+// CHECK-LABEL: "symbols": [
+// CHECK-LABEL: "precise": "s:18PlatformSupersedes1SV",
+// CHECK: "availability": [
+// CHECK-NEXT: {
+// CHECK-NEXT: "domain": "iOS",
+// CHECK-NEXT: "introduced": {
+// CHECK-NEXT: "major": 26,
+// CHECK-NEXT: "minor": 2
+// CHECK-NEXT: },
+// CHECK-NEXT: "obsoleted": {
+// CHECK-NEXT: "major": 26,
+// CHECK-NEXT: "minor": 4
+// CHECK-NEXT: }
+// CHECK-NEXT: },
+// CHECK-NEXT: {
+// CHECK-NEXT: "domain": "macOS",
+// CHECK-NEXT: "introduced": {
+// CHECK-NEXT: "major": 26
+// CHECK-NEXT: "minor": 4
+// CHECK-NEXT: }
+// CHECK-NEXT: },
+// CHECK-NEXT: {
+// CHECK-NEXT: "domain": "tvOS",
+// CHECK-NEXT: "introduced": {
+// CHECK-NEXT: "major": 26
+// CHECK-NEXT: },
+// CHECK-NEXT: "isUnconditionallyDeprecated": true
+// CHECK-NEXT: },
+// CHECK-NEXT: {
+// CHECK-NEXT: "domain": "visionOS",
+// CHECK-NEXT: "introduced": {
+// CHECK-NEXT: "major": 26
+// CHECK-NEXT: }
+// CHECK-NEXT: },
+// FIXME: [availability] watchOS introduction should be 11
+// CHECK-NEXT: {
+// CHECK-NEXT: "domain": "watchOS",
+// CHECK-NEXT: "introduced": {
+// CHECK-NEXT: "major": 26
+// CHECK-NEXT: }
+// CHECK-NEXT: }
+// CHECK-NEXT: ]
+
+@available(anyAppleOS, introduced: 26)
+@available(macOS, introduced: 26.4)
+@available(iOS, introduced: 26.2, obsoleted: 26.4)
+@available(watchOS 11, *)
+@available(tvOS, deprecated)
+public struct S {}
diff --git a/test/SymbolGraph/Symbols/Mixins/Availability/Duplicated/MessageLastWins.swift b/test/SymbolGraph/Symbols/Mixins/Availability/Duplicated/MessageLastWins.swift
index 157ea906da57d..82705171f153a 100644
--- a/test/SymbolGraph/Symbols/Mixins/Availability/Duplicated/MessageLastWins.swift
+++ b/test/SymbolGraph/Symbols/Mixins/Availability/Duplicated/MessageLastWins.swift
@@ -13,13 +13,13 @@ public func foo() {}
 // CHECK-LABEL: "precise": "s:15MessageLastWins3fooyyF",
 // CHECK: "availability": [
 // CHECK-NEXT:   {
-// CHECK-NEXT:     "domain": "macOS",
-// CHECK-NEXT:     "message": "second",
+// CHECK-NEXT:     "domain": "iOS",
+// CHECK-NEXT:     "message": "iOS",
 // CHECK-NEXT:     "isUnconditionallyDeprecated": true
 // CHECK-NEXT:   },
 // CHECK-NEXT:   {
-// CHECK-NEXT:     "domain": "iOS",
-// CHECK-NEXT:     "message": "iOS",
+// CHECK-NEXT:     "domain": "macOS",
+// CHECK-NEXT:     "message": "second",
 // CHECK-NEXT:     "isUnconditionallyDeprecated": true
 // CHECK-NEXT:   }
 // CHECK-NEXT: ]
diff --git a/test/SymbolGraph/Symbols/Mixins/Availability/OnlyActive.swift b/test/SymbolGraph/Symbols/Mixins/Availability/OnlyActive.swift
new file mode 100644
index 0000000000000..f078bb0ac0687
--- /dev/null
+++ b/test/SymbolGraph/Symbols/Mixins/Availability/OnlyActive.swift
@@ -0,0 +1,16 @@
+// RUN: %empty-directory(%t)
+// RUN: %target-build-swift %s -module-name OnlyActive -emit-module -emit-module-path %t/
+// RUN: %target-swift-symbolgraph-extract -module-name OnlyActive -I %t -pretty-print -active-platform-availability-only -output-dir %t
+// RUN: %FileCheck %s --input-file %t/OnlyActive.symbols.json
+
+// REQUIRES: OS=macosx
+
+@available(macOS 10.9, iOS 8.0, watchOS 8.0, tvOS 8.0, visionOS 1.0, *)
+public struct S {}
+
+// CHECK-NOT: iOS
+// CHECK: "domain": "macOS"
+// CHECK-NOT: tvOS
+// CHECK-NOT: visionOS
+// CHECK-NOT: watchOS
+
diff --git a/unittests/AST/TestContext.h b/unittests/AST/TestContext.h
index f830b3e0d34d7..7ddcf3427fad1 100644
--- a/unittests/AST/TestContext.h
+++ b/unittests/AST/TestContext.h
@@ -13,9 +13,13 @@
 #include "swift/AST/ASTContext.h"
 #include "swift/AST/DiagnosticEngine.h"
 #include "swift/AST/Module.h"
+#include "swift/AST/SILOptions.h"
+#include "swift/AST/SearchPathOptions.h"
 #include "swift/AST/SourceFile.h"
+#include "swift/Basic/CASOptions.h"
 #include "swift/Basic/LangOptions.h"
 #include "swift/Basic/SourceManager.h"
+#include "swift/Serialization/SerializationOptions.h"
 #include "swift/SymbolGraphGen/SymbolGraphOptions.h"
 
 #include "llvm/TargetParser/Host.h"
diff --git a/unittests/ClangImporter/ClangImporterTests.cpp b/unittests/ClangImporter/ClangImporterTests.cpp
index b643eb6b59b50..273fbb32420d5 100644
--- a/unittests/ClangImporter/ClangImporterTests.cpp
+++ b/unittests/ClangImporter/ClangImporterTests.cpp
@@ -1,5 +1,6 @@
 #include "swift/AST/ASTContext.h"
 #include "swift/AST/DiagnosticEngine.h"
+#include "swift/AST/SILOptions.h"
 #include "swift/AST/SearchPathOptions.h"
 #include "swift/Basic/CASOptions.h"
 #include "swift/Basic/Defer.h"
@@ -7,6 +8,7 @@
 #include "swift/Basic/LangOptions.h"
 #include "swift/Basic/SourceManager.h"
 #include "swift/ClangImporter/ClangImporter.h"
+#include "swift/Serialization/SerializationOptions.h"
 #include "swift/SymbolGraphGen/SymbolGraphOptions.h"
 #include "llvm/ADT/IntrusiveRefCntPtr.h"
 #include "llvm/Support/FileSystem.h"
diff --git a/unittests/Sema/SemaFixture.h b/unittests/Sema/SemaFixture.h
index bda2b433b4da2..f42993702a8aa 100644
--- a/unittests/Sema/SemaFixture.h
+++ b/unittests/Sema/SemaFixture.h
@@ -13,13 +13,17 @@
 #include "swift/AST/ASTContext.h"
 #include "swift/AST/DiagnosticEngine.h"
 #include "swift/AST/Module.h"
+#include "swift/AST/SILOptions.h"
+#include "swift/AST/SearchPathOptions.h"
 #include "swift/AST/SourceFile.h"
 #include "swift/AST/Type.h"
 #include "swift/AST/Types.h"
+#include "swift/Basic/CASOptions.h"
 #include "swift/Basic/LangOptions.h"
 #include "swift/Basic/Platform.h"
 #include "swift/Basic/SourceManager.h"
 #include "swift/Sema/ConstraintSystem.h"
+#include "swift/Serialization/SerializationOptions.h"
 #include "swift/SymbolGraphGen/SymbolGraphOptions.h"
 #include "llvm/ADT/SmallString.h"
 #include "llvm/ADT/StringRef.h"