Sema: Rename checkDeclarationAvailability().

Type checker functions with the prefix "check" usually check some requirement
and then diagnose it if it isn't satisfied. `checkDeclarationAvailability()`
doesn't diagnose on its own, so it should be named differently.

Author: tshortli

lib/Sema/ConstraintSystem.cpp

@@ -4683,7 +4683,8 @@ bool ConstraintSystem::isDeclUnavailable(const Decl *D,
   }
 
   auto availabilityContext = TypeChecker::availabilityAtLocation(loc, DC);
-  return checkDeclarationAvailability(D, DC, availabilityContext).has_value();
+  return getUnmetDeclAvailabilityRequirement(D, DC, availabilityContext)
+      .has_value();
 }
 
 bool ConstraintSystem::isConformanceUnavailable(ProtocolConformanceRef conformance,

lib/Sema/TypeCheckAvailability.cpp

@@ -3099,9 +3099,9 @@ bool diagnoseExplicitUnavailability(
 }
 
 std::optional<UnmetAvailabilityRequirement>
-swift::checkDeclarationAvailability(const Decl *decl,
-                                    const DeclContext *declContext,
-                                    AvailabilityContext availabilityContext) {
+swift::getUnmetDeclAvailabilityRequirement(
+    const Decl *decl, const DeclContext *declContext,
+    AvailabilityContext availabilityContext) {
   auto &ctx = declContext->getASTContext();
 
   // Generic parameters are always available.
@@ -3140,7 +3140,6 @@ swift::checkDeclarationAvailability(const Decl *decl,
   return std::nullopt;
 }
 
-
 /// Check if this is a subscript declaration inside String or
 /// Substring that returns String, and if so return true.
 bool isSubscriptReturningString(const ValueDecl *D, ASTContext &Context) {
@@ -4153,7 +4152,7 @@ bool swift::diagnoseDeclAvailability(const ValueDecl *D, SourceRange R,
   auto &ctx = DC->getASTContext();
 
   auto unmetRequirement =
-      checkDeclarationAvailability(D, DC, Where.getAvailability());
+      getUnmetDeclAvailabilityRequirement(D, DC, Where.getAvailability());
   auto requiredRange =
       unmetRequirement
           ? unmetRequirement->getRequiredNewerAvailabilityRange(ctx)

lib/Sema/TypeCheckAvailability.h

@@ -316,8 +316,9 @@ void diagnoseOverrideOfUnavailableDecl(ValueDecl *override,
 /// returns a result that describes the unmet availability requirements.
 /// Returns `std::nullopt` if the declaration is available.
 std::optional<UnmetAvailabilityRequirement>
-checkDeclarationAvailability(const Decl *decl, const DeclContext *declContext,
-                             AvailabilityContext availabilityContext);
+getUnmetDeclAvailabilityRequirement(const Decl *decl,
+                                    const DeclContext *declContext,
+                                    AvailabilityContext availabilityContext);
 
 /// Diagnose uses of the runtime support of the given type, such as
 /// type metadata and dynamic casting.

lib/Sema/TypeCheckPattern.cpp

@@ -41,10 +41,10 @@ extractEnumElement(DeclContext *DC, SourceLoc UseLoc,
                    const VarDecl *constant) {
   auto &ctx = DC->getASTContext();
   auto availabilityContext = TypeChecker::availabilityAtLocation(UseLoc, DC);
-  if (auto unmetRequirement =
-          checkDeclarationAvailability(constant, DC, availabilityContext)) {
+  if (auto requirement = getUnmetDeclAvailabilityRequirement(
+          constant, DC, availabilityContext)) {
     // Only diagnose explicit unavailability.
-    if (!unmetRequirement->getRequiredNewerAvailabilityRange(ctx))
+    if (!requirement->getRequiredNewerAvailabilityRange(ctx))
       diagnoseDeclAvailability(constant, UseLoc, nullptr,
                                ExportContext::forFunctionBody(DC, UseLoc));
   }