Sema: Adopt AvailabilityContext in ExportContext.

Query for an AvailabilityContext instead of computing availability with a
DeclContext traversal when forming an ExportContext.

Author: tshortli

lib/Sema/TypeCheckAvailability.cpp

@@ -47,23 +47,13 @@ using namespace swift;
 static const Decl *
 concreteSyntaxDeclForAvailableAttribute(const Decl *AbstractSyntaxDecl);
 
-ExportContext::ExportContext(
-    DeclContext *DC, AvailabilityRange runningOSVersion,
-    FragileFunctionKind kind, bool spi, bool exported, bool implicit,
-    bool deprecated, std::optional<PlatformKind> unavailablePlatformKind)
-    : DC(DC), RunningOSVersion(runningOSVersion), FragileKind(kind) {
+ExportContext::ExportContext(DeclContext *DC, AvailabilityContext availability,
+                             FragileFunctionKind kind, bool spi, bool exported,
+                             bool implicit)
+    : DC(DC), Availability(availability), FragileKind(kind) {
   SPI = spi;
   Exported = exported;
   Implicit = implicit;
-  Deprecated = deprecated;
-  if (unavailablePlatformKind) {
-    Unavailable = 1;
-    Platform = unsigned(*unavailablePlatformKind);
-  } else {
-    Unavailable = 0;
-    Platform = 0;
-  }
-
   Reason = unsigned(ExportabilityReason::General);
 }
 
@@ -196,10 +186,8 @@ static void forEachOuterDecl(DeclContext *DC, Fn fn) {
   }
 }
 
-static void
-computeExportContextBits(ASTContext &Ctx, Decl *D, bool *spi, bool *implicit,
-                         bool *deprecated,
-                         std::optional<PlatformKind> *unavailablePlatformKind) {
+static void computeExportContextBits(ASTContext &Ctx, Decl *D, bool *spi,
+                                     bool *implicit) {
   if (D->isSPI() ||
       D->isAvailableAsSPI())
     *spi = true;
@@ -211,18 +199,10 @@ computeExportContextBits(ASTContext &Ctx, Decl *D, bool *spi, bool *implicit,
   if (D->isImplicit() && !isDeferBody)
     *implicit = true;
 
-  if (D->getAttrs().isDeprecated(Ctx))
-    *deprecated = true;
-
-  if (auto *A = D->getAttrs().getUnavailable(Ctx)) {
-    *unavailablePlatformKind = A->Platform;
-  }
-
   if (auto *PBD = dyn_cast<PatternBindingDecl>(D)) {
     for (unsigned i = 0, e = PBD->getNumPatternEntries(); i < e; ++i) {
       if (auto *VD = PBD->getAnchoringVarDecl(i))
-        computeExportContextBits(Ctx, VD, spi, implicit, deprecated,
-                                 unavailablePlatformKind);
+        computeExportContextBits(Ctx, VD, spi, implicit);
     }
   }
 }
@@ -232,56 +212,40 @@ ExportContext ExportContext::forDeclSignature(Decl *D) {
 
   auto *DC = D->getInnermostDeclContext();
   auto fragileKind = DC->getFragileFunctionKind();
-  auto runningOSVersion =
+  auto availabilityContext =
       (Ctx.LangOpts.DisableAvailabilityChecking
-           ? AvailabilityRange::alwaysAvailable()
-           : TypeChecker::overApproximateAvailabilityAtLocation(D->getLoc(),
-                                                                DC));
+           ? AvailabilityContext::getDefault(Ctx)
+           : TypeChecker::availabilityAtLocation(D->getLoc(), DC));
   bool spi = Ctx.LangOpts.LibraryLevel == LibraryLevel::SPI;
   bool implicit = false;
-  bool deprecated = false;
-  std::optional<PlatformKind> unavailablePlatformKind;
-  computeExportContextBits(Ctx, D, &spi, &implicit, &deprecated,
-                           &unavailablePlatformKind);
-  forEachOuterDecl(D->getDeclContext(),
-                   [&](Decl *D) {
-                     computeExportContextBits(Ctx, D,
-                                              &spi, &implicit, &deprecated,
-                                              &unavailablePlatformKind);
-                   });
+  computeExportContextBits(Ctx, D, &spi, &implicit);
+  forEachOuterDecl(D->getDeclContext(), [&](Decl *D) {
+    computeExportContextBits(Ctx, D, &spi, &implicit);
+  });
 
   bool exported = ::isExported(D);
 
-  return ExportContext(DC, runningOSVersion, fragileKind,
-                       spi, exported, implicit, deprecated,
-                       unavailablePlatformKind);
+  return ExportContext(DC, availabilityContext, fragileKind, spi, exported,
+                       implicit);
 }
 
 ExportContext ExportContext::forFunctionBody(DeclContext *DC, SourceLoc loc) {
   auto &Ctx = DC->getASTContext();
 
   auto fragileKind = DC->getFragileFunctionKind();
-  auto runningOSVersion =
+  auto availabilityContext =
       (Ctx.LangOpts.DisableAvailabilityChecking
-           ? AvailabilityRange::alwaysAvailable()
-           : TypeChecker::overApproximateAvailabilityAtLocation(loc, DC));
-
+           ? AvailabilityContext::getDefault(Ctx)
+           : TypeChecker::availabilityAtLocation(loc, DC));
   bool spi = Ctx.LangOpts.LibraryLevel == LibraryLevel::SPI;
   bool implicit = false;
-  bool deprecated = false;
-  std::optional<PlatformKind> unavailablePlatformKind;
-  forEachOuterDecl(DC,
-                   [&](Decl *D) {
-                     computeExportContextBits(Ctx, D,
-                                              &spi, &implicit, &deprecated,
-                                              &unavailablePlatformKind);
-                   });
+  forEachOuterDecl(
+      DC, [&](Decl *D) { computeExportContextBits(Ctx, D, &spi, &implicit); });
 
   bool exported = false;
 
-  return ExportContext(DC, runningOSVersion, fragileKind,
-                       spi, exported, implicit, deprecated,
-                       unavailablePlatformKind);
+  return ExportContext(DC, availabilityContext, fragileKind, spi, exported,
+                       implicit);
 }
 
 ExportContext ExportContext::forConformance(DeclContext *DC,
@@ -310,16 +274,11 @@ ExportContext ExportContext::withExported(bool exported) const {
 ExportContext ExportContext::withRefinedAvailability(
     const AvailabilityRange &availability) const {
   auto copy = *this;
-  copy.RunningOSVersion.intersectWith(availability);
+  copy.Availability.constrainWithPlatformRange(availability,
+                                               DC->getASTContext());
   return copy;
 }
 
-std::optional<PlatformKind> ExportContext::getUnavailablePlatformKind() const {
-  if (Unavailable)
-    return PlatformKind(Platform);
-  return std::nullopt;
-}
-
 bool ExportContext::mustOnlyReferenceExportedDecls() const {
   return Exported || FragileKind.kind != FragileFunctionKind::None;
 }

lib/Sema/TypeCheckAvailability.h

@@ -14,7 +14,7 @@
 #define SWIFT_SEMA_TYPE_CHECK_AVAILABILITY_H
 
 #include "swift/AST/AttrKind.h"
-#include "swift/AST/Availability.h"
+#include "swift/AST/AvailabilityContext.h"
 #include "swift/AST/DeclContext.h"
 #include "swift/AST/Identifier.h"
 #include "swift/Basic/LLVM.h"
@@ -103,20 +103,16 @@ enum class ExportabilityReason : unsigned {
 /// without producing a warning or error, respectively.
 class ExportContext {
   DeclContext *DC;
-  AvailabilityRange RunningOSVersion;
+  AvailabilityContext Availability;
   FragileFunctionKind FragileKind;
   unsigned SPI : 1;
   unsigned Exported : 1;
-  unsigned Deprecated : 1;
   unsigned Implicit : 1;
-  unsigned Unavailable : 1;
-  unsigned Platform : 8;
   unsigned Reason : 3;
 
-  ExportContext(DeclContext *DC, AvailabilityRange runningOSVersion,
+  ExportContext(DeclContext *DC, AvailabilityContext availability,
                 FragileFunctionKind kind, bool spi, bool exported,
-                bool implicit, bool deprecated,
-                std::optional<PlatformKind> unavailablePlatformKind);
+                bool implicit);
 
 public:
 
@@ -161,7 +157,7 @@ class ExportContext {
   DeclContext *getDeclContext() const { return DC; }
 
   AvailabilityRange getAvailabilityRange() const {
-    return RunningOSVersion;
+    return Availability.getPlatformRange();
   }
 
   /// If not 'None', the context has the inlinable function body restriction.
@@ -180,9 +176,11 @@ class ExportContext {
 
   /// If true, the context is part of a deprecated declaration and can
   /// reference other deprecated declarations without warning.
-  bool isDeprecated() const { return Deprecated; }
+  bool isDeprecated() const { return Availability.isDeprecated(); }
 
-  std::optional<PlatformKind> getUnavailablePlatformKind() const;
+  std::optional<PlatformKind> getUnavailablePlatformKind() const {
+    return Availability.getUnavailablePlatformKind();
+  }
 
   /// If true, the context can only reference exported declarations, either
   /// because it is the signature context of an exported declaration, or

test/Sema/availability_deprecated_script_mode.swift

@@ -20,11 +20,8 @@ var testDeprecatedReferencingDeprecated2: () {
   x - y // no-warning
 }
 
-// FIXME: This doesn't work because the file is parsed in script mode.
 @available(*, deprecated)
 var testDeprecatedReferencingDeprecated3: () = DummyType() - DummyType()
-// expected-warning@-1 {{'-' is deprecated}}
-// expected-note@-2 {{use '&-' instead}}
 
 struct HasDeprecatedMembers {
   @available(*, deprecated)
@@ -41,4 +38,4 @@ struct HasDeprecatedMembers {
 
   @available(*, deprecated)
   var testDeprecatedReferencingDeprecated3: () = DummyType() - DummyType() // no-warning
-}
+}

test/attr/attr_availability_transitive_osx.swift

@@ -133,7 +133,7 @@ extension Outer {
 
   @available(*, unavailable)
   func osx_universally_unavailable_call_osx() {
-    osx() // OK
+    osx() // expected-error {{'osx()' is unavailable in macOS}}
   }
 
   // rdar://92551870