[AST] InitAccessors: Requestify a "has init accessor" check

Author: xedin

include/swift/AST/Decl.h

@@ -5317,6 +5317,10 @@ class AbstractStorageDecl : public ValueDecl {
   /// it.
   bool hasStorage() const;
 
+  /// Return true if this is a VarDecl that has init accessor associated
+  /// with it.
+  bool hasInitAccessor() const;
+
   /// Return true if this storage has the basic accessors/capability
   /// to be mutated.  This is generally constant after the accessors are
   /// installed by the parser/importer/whatever.

include/swift/AST/TypeCheckRequests.h

@@ -4312,6 +4312,22 @@ class IsNonUserModuleRequest
   bool isCached() const { return true; }
 };
 
+class HasInitAccessorRequest
+    : public SimpleRequest<HasInitAccessorRequest, bool(AbstractStorageDecl *),
+                           RequestFlags::Cached> {
+public:
+  using SimpleRequest::SimpleRequest;
+
+private:
+  friend SimpleRequest;
+
+  // Evaluation.
+  bool evaluate(Evaluator &evaluator, AbstractStorageDecl *decl) const;
+
+public:
+  bool isCached() const { return true; }
+};
+
 class InitAccessorReferencedVariablesRequest
     : public SimpleRequest<InitAccessorReferencedVariablesRequest,
                            ArrayRef<VarDecl *>(DeclAttribute *, AccessorDecl *,

include/swift/AST/TypeCheckerTypeIDZone.def

@@ -487,6 +487,9 @@ SWIFT_REQUEST(TypeChecker, IsNonUserModuleRequest,
 SWIFT_REQUEST(TypeChecker, TypeCheckObjCImplementationRequest,
               unsigned(ExtensionDecl *),
               Cached, NoLocationInfo)
+SWIFT_REQUEST(TypeChecker, HasInitAccessorRequest,
+              bool(AbstractStorageDecl *), Cached,
+              NoLocationInfo)
 SWIFT_REQUEST(TypeChecker, InitAccessorReferencedVariablesRequest,
               ArrayRef<VarDecl *>(DeclAttribute *, AccessorDecl *,
                                   ArrayRef<Identifier>),

lib/AST/Decl.cpp

@@ -6720,6 +6720,12 @@ Type AbstractStorageDecl::getValueInterfaceType() const {
   return cast<SubscriptDecl>(this)->getElementInterfaceType();
 }
 
+bool AbstractStorageDecl::hasInitAccessor() const {
+  return evaluateOrDefault(
+      getASTContext().evaluator,
+      HasInitAccessorRequest{const_cast<AbstractStorageDecl *>(this)}, false);
+}
+
 VarDecl::VarDecl(DeclKind kind, bool isStatic, VarDecl::Introducer introducer,
                  SourceLoc nameLoc, Identifier name,
                  DeclContext *dc, StorageIsMutable_t supportsMutation)

lib/Sema/TypeCheckStorage.cpp

@@ -301,8 +301,12 @@ StoredPropertiesAndMissingMembersRequest::evaluate(Evaluator &evaluator,
   return decl->getASTContext().AllocateCopy(results);
 }
 
-/// Determine whether the given variable has an init accessor.
-static bool hasInitAccessor(VarDecl *var) {
+bool HasInitAccessorRequest::evaluate(Evaluator &evaluator,
+                                      AbstractStorageDecl *decl) const {
+  auto *var = dyn_cast<VarDecl>(decl);
+  if (!var)
+    return false;
+
   if (var->getAccessor(AccessorKind::Init))
     return true;
 
@@ -340,7 +344,7 @@ InitAccessorPropertiesRequest::evaluate(Evaluator &evaluator,
   SmallVector<VarDecl *, 4> results;
   for (auto *member : decl->getMembers()) {
     auto *var = dyn_cast<VarDecl>(member);
-    if (!var || var->isStatic() || !hasInitAccessor(var)) {
+    if (!var || var->isStatic() || !var->hasInitAccessor()) {
       continue;
     }