Revert "Eliminate Observable circular reference errors via lazier TypeRefinementContext building"

include/swift/AST/Availability.h

@@ -377,13 +377,6 @@ class AvailabilityInference {
   annotatedAvailableRangeForAttr(const SpecializeAttr *attr, ASTContext &ctx);
 };
 
-/// Given a declaration upon which an availability attribute would appear in
-/// concrete syntax, return a declaration to which the parser
-/// actually attaches the attribute in the abstract syntax tree. We use this
-/// function to determine whether the concrete syntax already has an
-/// availability attribute.
-const Decl *abstractSyntaxDeclForAvailableAttribute(const Decl *D);
-
 } // end namespace swift
 
 #endif

include/swift/AST/TypeCheckRequests.h

@@ -63,7 +63,6 @@ class TypeAliasDecl;
 class TypeLoc;
 class Witness;
 class TypeResolution;
-class TypeRefinementContext;
 struct TypeWitnessAndDecl;
 class ValueDecl;
 enum class OpaqueReadOwnership: uint8_t;
@@ -4434,25 +4433,6 @@ class InitAccessorReferencedVariablesRequest
   bool isCached() const { return true; }
 };
 
-/// Expand the children of the type refinement context for the given
-/// declaration.
-class ExpandChildTypeRefinementContextsRequest
-    : public SimpleRequest<ExpandChildTypeRefinementContextsRequest,
-                           bool(Decl *, TypeRefinementContext *),
-                           RequestFlags::Cached> {
-public:
-  using SimpleRequest::SimpleRequest;
-
-private:
-  friend SimpleRequest;
-
-  bool evaluate(Evaluator &evaluator, Decl *decl,
-                TypeRefinementContext *parentTRC) const;
-
-public:
-  bool isCached() const { return true; }
-};
-
 #define SWIFT_TYPEID_ZONE TypeChecker
 #define SWIFT_TYPEID_HEADER "swift/AST/TypeCheckerTypeIDZone.def"
 #include "swift/Basic/DefineTypeIDZone.h"

include/swift/AST/TypeCheckerTypeIDZone.def

@@ -506,6 +506,3 @@ SWIFT_REQUEST(TypeChecker, InitAccessorReferencedVariablesRequest,
               ArrayRef<VarDecl *>(DeclAttribute *, AccessorDecl *,
                                   ArrayRef<Identifier>),
               Cached, NoLocationInfo)
-SWIFT_REQUEST(TypeChecker, ExpandChildTypeRefinementContextsRequest,
-              bool(Decl *, TypeRefinementContext *),
-              Cached, NoLocationInfo)

include/swift/AST/TypeRefinementContext.h

@@ -297,9 +297,6 @@ class TypeRefinementContext : public ASTAllocated<TypeRefinementContext> {
   static StringRef getReasonName(Reason R);
 };
 
-void simple_display(llvm::raw_ostream &out,
-                    const TypeRefinementContext *trc);
-
 } // end namespace swift
 
 #endif

lib/AST/Availability.cpp

@@ -225,8 +225,6 @@ AvailabilityInference::attrForAnnotatedAvailableRange(const Decl *D,
                                                       ASTContext &Ctx) {
   const AvailableAttr *bestAvailAttr = nullptr;
 
-  D = abstractSyntaxDeclForAvailableAttribute(D);
-
   for (auto Attr : D->getAttrs()) {
     auto *AvailAttr = dyn_cast<AvailableAttr>(Attr);
     if (AvailAttr == nullptr || !AvailAttr->Introduced.has_value() ||
@@ -751,31 +749,3 @@ ASTContext::getSwift5PlusAvailability(llvm::VersionTuple swiftVersion) {
 bool ASTContext::supportsVersionedAvailability() const {
   return minimumAvailableOSVersionForTriple(LangOpts.Target).has_value();
 }
-
-const Decl *
-swift::abstractSyntaxDeclForAvailableAttribute(const Decl *ConcreteSyntaxDecl) {
-  // This function needs to be kept in sync with its counterpart,
-  // concreteSyntaxDeclForAvailableAttribute().
-
-  if (auto *PBD = dyn_cast<PatternBindingDecl>(ConcreteSyntaxDecl)) {
-    // Existing @available attributes in the AST are attached to VarDecls
-    // rather than PatternBindingDecls, so we return the first VarDecl for
-    // the pattern binding declaration.
-    // This is safe, even though there may be multiple VarDecls, because
-    // all parsed attribute that appear in the concrete syntax upon on the
-    // PatternBindingDecl are added to all of the VarDecls for the pattern
-    // binding.
-    for (auto index : range(PBD->getNumPatternEntries())) {
-      if (auto VD = PBD->getAnchoringVarDecl(index))
-        return VD;
-    }
-  } else if (auto *ECD = dyn_cast<EnumCaseDecl>(ConcreteSyntaxDecl)) {
-    // Similar to the PatternBindingDecl case above, we return the
-    // first EnumElementDecl.
-    if (auto *Elem = ECD->getFirstElement()) {
-      return Elem;
-    }
-  }
-
-  return ConcreteSyntaxDecl;
-}

lib/AST/Decl.cpp

@@ -2079,23 +2079,19 @@ bool VarDecl::isLayoutExposedToClients() const {
   if (!parent) return false;
   if (isStatic()) return false;
 
-
-  auto nominalAccess =
-    parent->getFormalAccessScope(/*useDC=*/nullptr,
-                                 /*treatUsableFromInlineAsPublic=*/true);
-  if (!nominalAccess.isPublic()) return false;
-
-  if (!parent->getAttrs().hasAttribute<FrozenAttr>() &&
-      !parent->getAttrs().hasAttribute<FixedLayoutAttr>())
-    return false;
-
   if (!hasStorage() &&
       !getAttrs().hasAttribute<LazyAttr>() &&
       !hasAttachedPropertyWrapper()) {
     return false;
   }
 
-  return true;
+  auto nominalAccess =
+    parent->getFormalAccessScope(/*useDC=*/nullptr,
+                                 /*treatUsableFromInlineAsPublic=*/true);
+  if (!nominalAccess.isPublic()) return false;
+
+  return (parent->getAttrs().hasAttribute<FrozenAttr>() ||
+          parent->getAttrs().hasAttribute<FixedLayoutAttr>());
 }
 
 /// Check whether the given type representation will be

lib/AST/TypeRefinementContext.cpp

@@ -20,7 +20,6 @@
 #include "swift/AST/Stmt.h"
 #include "swift/AST/Expr.h"
 #include "swift/AST/SourceFile.h"
-#include "swift/AST/TypeCheckRequests.h"
 #include "swift/AST/TypeRefinementContext.h"
 #include "swift/Basic/SourceManager.h"
 
@@ -193,18 +192,6 @@ TypeRefinementContext::findMostRefinedSubContext(SourceLoc Loc,
       !rangeContainsTokenLocWithGeneratedSource(SM, SrcRange, Loc))
     return nullptr;
 
-  // If this context is for a declaration, ensure that we've expanded the
-  // children of the declaration.
-  if (Node.getReason() == Reason::Decl ||
-      Node.getReason() == Reason::DeclImplicit) {
-    if (auto decl = Node.getAsDecl()) {
-      ASTContext &ctx = decl->getASTContext();
-      (void)evaluateOrDefault(
-          ctx.evaluator, ExpandChildTypeRefinementContextsRequest{decl, this},
-          false);
-    }
-  }
-
   // For the moment, we perform a linear search here, but we can and should
   // do something more efficient.
   for (TypeRefinementContext *Child : Children) {
@@ -367,10 +354,6 @@ void TypeRefinementContext::print(raw_ostream &OS, SourceManager &SrcMgr,
       OS << "extension." << ED->getExtendedType().getString();
     } else if (isa<TopLevelCodeDecl>(D)) {
       OS << "<top-level-code>";
-    } else if (auto PBD = dyn_cast<PatternBindingDecl>(D)) {
-      if (auto VD = PBD->getAnchoringVarDecl(0)) {
-        OS << VD->getName();
-      }
     }
   }
 
@@ -428,8 +411,3 @@ StringRef TypeRefinementContext::getReasonName(Reason R) {
 
   llvm_unreachable("Unhandled Reason in switch.");
 }
-
-void swift::simple_display(
-    llvm::raw_ostream &out, const TypeRefinementContext *trc) {
-  out << "TRC @" << trc;
-}