AST: Rename a couple of AvailabilityConstraint::Reason cases.

Choose names that don't imply availability is versioned, since custom
availability will support domains that are version-less (they are simply
available or unavailable).

Author: tshortli

include/swift/AST/AvailabilityConstraint.h

@@ -51,19 +51,21 @@ class AvailabilityConstraint {
     /// constraint.
     Obsoleted,
 
-    /// The declaration is only available in a later version. For example,
-    /// the declaration might only be introduced in the Swift 6 language mode
-    /// while the module is being compiled in the Swift 5 language mode.
-    IntroducedInLaterVersion,
-
-    /// The declaration is referenced in a context that does not have an
-    /// adequate minimum version constraint. For example, a reference to a
-    /// declaration that is introduced in macOS 13 from a context that may
-    /// execute on earlier versions of macOS has this constraint. This
-    /// kind of constraint can be satisfied by tightening the minimum
-    /// version of the context with `if #available(...)` or by adding or
-    /// adjusting an `@available` attribute.
-    IntroducedInLaterDynamicVersion,
+    /// The declaration is not available in the deployment configuration
+    /// specified for this compilation. For example, the declaration might only
+    /// be introduced in the Swift 6 language mode while the module is being
+    /// compiled in the Swift 5 language mode. These availability constraints
+    /// cannot be satisfied by adding constraining contextual availability using
+    /// `@available` attributes or `if #available` queries.
+    UnavailableForDeployment,
+
+    /// The declaration is referenced in a context that does not have adequate
+    /// availability constraints. For example, a reference to a declaration that
+    /// was introduced in macOS 13 from a context that may execute on earlier
+    /// versions of macOS cannot satisfy this constraint. The constraint
+    /// can be satisfied, though, by introducing an `@available` attribute or an
+    /// `if #available(...)` query.
+    PotentiallyUnavailable,
   };
 
   /// Classifies constraints into different high level categories.
@@ -93,14 +95,13 @@ class AvailabilityConstraint {
   }
 
   static AvailabilityConstraint
-  introducedInLaterVersion(SemanticAvailableAttr attr) {
-    return AvailabilityConstraint(Reason::IntroducedInLaterVersion, attr);
+  unavailableForDeployment(SemanticAvailableAttr attr) {
+    return AvailabilityConstraint(Reason::UnavailableForDeployment, attr);
   }
 
   static AvailabilityConstraint
-  introducedInLaterDynamicVersion(SemanticAvailableAttr attr) {
-    return AvailabilityConstraint(Reason::IntroducedInLaterDynamicVersion,
-                                  attr);
+  potentiallyUnavailable(SemanticAvailableAttr attr) {
+    return AvailabilityConstraint(Reason::PotentiallyUnavailable, attr);
   }
 
   Reason getReason() const { return attrAndReason.getInt(); }
@@ -112,9 +113,9 @@ class AvailabilityConstraint {
     switch (getReason()) {
     case Reason::UnconditionallyUnavailable:
     case Reason::Obsoleted:
-    case Reason::IntroducedInLaterVersion:
+    case Reason::UnavailableForDeployment:
       return Kind::Unavailable;
-    case Reason::IntroducedInLaterDynamicVersion:
+    case Reason::PotentiallyUnavailable:
       return Kind::PotentiallyAvailable;
     }
   }

lib/AST/AvailabilityConstraint.cpp

@@ -28,9 +28,9 @@ AvailabilityConstraint::getRequiredNewerAvailabilityRange(
   switch (getReason()) {
   case Reason::UnconditionallyUnavailable:
   case Reason::Obsoleted:
-  case Reason::IntroducedInLaterVersion:
+  case Reason::UnavailableForDeployment:
     return std::nullopt;
-  case Reason::IntroducedInLaterDynamicVersion:
+  case Reason::PotentiallyUnavailable:
     return getAttr().getIntroducedRange(ctx);
   }
 }
@@ -60,12 +60,12 @@ static bool constraintIsStronger(const AvailabilityConstraint &lhs,
     return false;
 
   case AvailabilityConstraint::Reason::Obsoleted:
-    // Pick the earliest obsoleted version.
+    // Pick the larger obsoleted range.
     return *lhs.getAttr().getObsoleted() < *rhs.getAttr().getObsoleted();
 
-  case AvailabilityConstraint::Reason::IntroducedInLaterVersion:
-  case AvailabilityConstraint::Reason::IntroducedInLaterDynamicVersion:
-    // Pick the latest introduced version.
+  case AvailabilityConstraint::Reason::UnavailableForDeployment:
+  case AvailabilityConstraint::Reason::PotentiallyUnavailable:
+    // Pick the smaller introduced range.
     return *lhs.getAttr().getIntroduced() > *rhs.getAttr().getIntroduced();
   }
 }
@@ -159,10 +159,10 @@ getAvailabilityConstraintForAttr(const Decl *decl,
   // FIXME: [availability] Expand this to cover custom versioned domains
   if (attr.isPlatformSpecific()) {
     if (!context.getPlatformRange().isContainedIn(introducedRange))
-      return AvailabilityConstraint::introducedInLaterDynamicVersion(attr);
+      return AvailabilityConstraint::potentiallyUnavailable(attr);
   } else if (deploymentRange &&
              !deploymentRange->isContainedIn(introducedRange)) {
-    return AvailabilityConstraint::introducedInLaterVersion(attr);
+    return AvailabilityConstraint::unavailableForDeployment(attr);
   }
 
   return std::nullopt;

lib/AST/AvailabilityContext.cpp

@@ -57,10 +57,10 @@ bool AvailabilityContext::Info::constrainWith(
     switch (constraint.getReason()) {
     case AvailabilityConstraint::Reason::UnconditionallyUnavailable:
     case AvailabilityConstraint::Reason::Obsoleted:
-    case AvailabilityConstraint::Reason::IntroducedInLaterVersion:
+    case AvailabilityConstraint::Reason::UnavailableForDeployment:
       isConstrained |= constrainUnavailability(domain);
       break;
-    case AvailabilityConstraint::Reason::IntroducedInLaterDynamicVersion:
+    case AvailabilityConstraint::Reason::PotentiallyUnavailable:
       // FIXME: [availability] Support versioning for other kinds of domains.
       DEBUG_ASSERT(domain.isPlatform());
       if (domain.isPlatform())
@@ -189,7 +189,6 @@ AvailabilityContext::forDeploymentTarget(const ASTContext &ctx) {
 AvailabilityRange AvailabilityContext::getPlatformRange() const {
   return storage->info.PlatformRange;
 }
-}
 
 bool AvailabilityContext::isUnavailable() const {
   return storage->info.UnavailableDomains.size() > 0;

lib/Sema/TypeCheckAvailability.cpp

@@ -3007,9 +3007,9 @@ bool shouldHideDomainNameForConstraintDiagnostic(
   case AvailabilityDomain::Kind::SwiftLanguage:
     switch (constraint.getReason()) {
     case AvailabilityConstraint::Reason::UnconditionallyUnavailable:
-    case AvailabilityConstraint::Reason::IntroducedInLaterVersion:
+    case AvailabilityConstraint::Reason::UnavailableForDeployment:
       return false;
-    case AvailabilityConstraint::Reason::IntroducedInLaterDynamicVersion:
+    case AvailabilityConstraint::Reason::PotentiallyUnavailable:
     case AvailabilityConstraint::Reason::Obsoleted:
       return true;
     }
@@ -3058,7 +3058,7 @@ bool diagnoseExplicitUnavailability(SourceLoc loc,
                   proto)
         .highlight(attr.getParsedAttr()->getRange());
     break;
-  case AvailabilityConstraint::Reason::IntroducedInLaterVersion:
+  case AvailabilityConstraint::Reason::UnavailableForDeployment:
     diags.diagnose(ext, diag::conformance_availability_introduced_in_version,
                    type, proto, domain, *attr.getIntroduced());
     break;
@@ -3068,7 +3068,7 @@ bool diagnoseExplicitUnavailability(SourceLoc loc,
                   domain, *attr.getObsoleted())
         .highlight(attr.getParsedAttr()->getRange());
     break;
-  case AvailabilityConstraint::Reason::IntroducedInLaterDynamicVersion:
+  case AvailabilityConstraint::Reason::PotentiallyUnavailable:
     llvm_unreachable("unexpected constraint");
   }
   return true;
@@ -3478,7 +3478,7 @@ bool diagnoseExplicitUnavailability(
     diags.diagnose(D, diag::availability_marked_unavailable, D)
         .highlight(sourceRange);
     break;
-  case AvailabilityConstraint::Reason::IntroducedInLaterVersion:
+  case AvailabilityConstraint::Reason::UnavailableForDeployment:
     diags
         .diagnose(D, diag::availability_introduced_in_version, D, domain,
                   *Attr.getIntroduced())
@@ -3490,7 +3490,7 @@ bool diagnoseExplicitUnavailability(
                   *Attr.getObsoleted())
         .highlight(sourceRange);
     break;
-  case AvailabilityConstraint::Reason::IntroducedInLaterDynamicVersion:
+  case AvailabilityConstraint::Reason::PotentiallyUnavailable:
     llvm_unreachable("unexpected constraint");
     break;
   }

lib/Sema/TypeCheckDeclOverride.cpp

@@ -251,10 +251,10 @@ static bool isUnavailableInAllVersions(ValueDecl *decl) {
   for (auto constraint : constraints) {
     switch (constraint.getReason()) {
     case AvailabilityConstraint::Reason::UnconditionallyUnavailable:
-    case AvailabilityConstraint::Reason::IntroducedInLaterVersion:
+    case AvailabilityConstraint::Reason::UnavailableForDeployment:
       return true;
     case AvailabilityConstraint::Reason::Obsoleted:
-    case AvailabilityConstraint::Reason::IntroducedInLaterDynamicVersion:
+    case AvailabilityConstraint::Reason::PotentiallyUnavailable:
       break;
     }
   }