Merge pull request swiftlang#28092 from CodaFi/typing-of-the-dead

Kill the LazyResolver

Author: CodaFi

include/swift/AST/ASTContext.h

@@ -70,7 +70,6 @@ namespace swift {
   class LazyContextData;
   class LazyIterableDeclContextData;
   class LazyMemberLoader;
-  class LazyResolver;
   class PatternBindingDecl;
   class PatternBindingInitializer;
   class SourceFile;
@@ -102,6 +101,7 @@ namespace swift {
   class SourceManager;
   class ValueDecl;
   class DiagnosticEngine;
+  class TypeChecker;
   class TypeCheckerDebugConsumer;
   struct RawComment;
   class DocComment;
@@ -404,28 +404,14 @@ class ASTContext final {
   /// Set a new stats reporter.
   void setStatsReporter(UnifiedStatsReporter *stats);
 
-  /// Creates a new lazy resolver by passing the ASTContext and the other
-  /// given arguments to a newly-allocated instance of \c ResolverType.
-  ///
-  /// \returns true if a new lazy resolver was created, false if there was
-  /// already a lazy resolver registered.
-  template<typename ResolverType, typename ... Args>
-  bool createLazyResolverIfMissing(Args && ...args) {
-    if (getLazyResolver())
-      return false;
-
-    setLazyResolver(new ResolverType(*this, std::forward<Args>(args)...));
-    return true;
-  }
-
-  /// Retrieve the lazy resolver for this context.
-  LazyResolver *getLazyResolver() const;
-
 private:
-  /// Set the lazy resolver for this context.
-  void setLazyResolver(LazyResolver *resolver);
+  friend class TypeChecker;
 
+  void installGlobalTypeChecker(TypeChecker *TC);
 public:
+  /// Retrieve the global \c TypeChecker instance associated with this context.
+  TypeChecker *getLegacyGlobalTypeChecker() const;
+
   /// getIdentifier - Return the uniqued and AST-Context-owned version of the
   /// specified string.
   Identifier getIdentifier(StringRef Str) const;

include/swift/AST/ASTTypeIDZone.def

@@ -26,6 +26,8 @@ SWIFT_TYPEID(Requirement)
 SWIFT_TYPEID(ResilienceExpansion)
 SWIFT_TYPEID(Type)
 SWIFT_TYPEID(TypePair)
+SWIFT_TYPEID(TypeWitnessAndDecl)
+SWIFT_TYPEID(Witness)
 SWIFT_TYPEID_NAMED(ConstructorDecl *, ConstructorDecl)
 SWIFT_TYPEID_NAMED(CustomAttr *, CustomAttr)
 SWIFT_TYPEID_NAMED(Decl *, Decl)

include/swift/AST/ASTTypeIDs.h

@@ -51,9 +51,11 @@ enum class ResilienceExpansion : unsigned;
 class Type;
 class ValueDecl;
 class VarDecl;
+class Witness;
 class TypeAliasDecl;
 class Type;
 struct TypePair;
+struct TypeWitnessAndDecl;
 enum class AncestryFlags : uint8_t;
 enum class ImplicitMemberAction : uint8_t;
 

include/swift/AST/Decl.h

@@ -7326,6 +7326,11 @@ inline void simple_display(llvm::raw_ostream &out,
   simple_display(out, static_cast<const Decl *>(decl));
 }
 
+inline void simple_display(llvm::raw_ostream &out,
+                           const AssociatedTypeDecl *decl) {
+  simple_display(out, static_cast<const Decl *>(decl));
+}
+
 /// Display GenericContext.
 ///
 /// The template keeps this sorted down in the overload set relative to the

include/swift/AST/DeclContext.h

@@ -50,7 +50,6 @@ namespace swift {
   class ExtensionDecl;
   class Expr;
   class GenericParamList;
-  class LazyResolver;
   class LazyMemberLoader;
   class GenericSignature;
   class GenericTypeParamDecl;

include/swift/AST/GenericSignatureBuilder.h

@@ -49,7 +49,6 @@ class DependentMemberType;
 class GenericParamList;
 class GenericSignatureBuilder;
 class GenericTypeParamType;
-class LazyResolver;
 class ModuleDecl;
 class Pattern;
 class ProtocolConformance;

include/swift/AST/LazyResolver.h

@@ -10,7 +10,7 @@
 //
 //===----------------------------------------------------------------------===//
 //
-// This file defines the LazyResolver abstract interface.
+// This file defines the abstract interfaces for lazily resolving declarations.
 //
 //===----------------------------------------------------------------------===//
 
@@ -37,23 +37,6 @@ class TypeDecl;
 class ValueDecl;
 class VarDecl;
 
-/// Abstract interface used to lazily resolve aspects of the AST, such as the
-/// types of declarations or protocol conformance structures.
-class LazyResolver {
-public:
-  virtual ~LazyResolver();
-
-  /// Resolve the type witnesses for the given associated type within the given
-  /// protocol conformance.
-  virtual void resolveTypeWitness(const NormalProtocolConformance *conformance,
-                                  AssociatedTypeDecl *assocType) = 0;
-
-  /// Resolve the witness for the given non-type requirement within
-  /// the given protocol conformance.
-  virtual void resolveWitness(const NormalProtocolConformance *conformance,
-                              ValueDecl *requirement) = 0;
-};
-
 class LazyMemberLoader;
 
 /// Context data for lazy deserialization.

include/swift/AST/Module.h

@@ -58,7 +58,6 @@ namespace swift {
   class FileUnit;
   class FuncDecl;
   class InfixOperatorDecl;
-  class LazyResolver;
   class LinkLibrary;
   class ModuleLoader;
   class NominalTypeDecl;

include/swift/AST/ProtocolConformance.h

@@ -52,7 +52,7 @@ typedef llvm::DenseMap<ValueDecl *, Witness> WitnessMap;
 
 /// Map from associated type requirements to the corresponding type and
 /// the type declaration that was used to satisfy the requirement.
-typedef llvm::DenseMap<AssociatedTypeDecl *, std::pair<Type, TypeDecl*>>
+typedef llvm::DenseMap<AssociatedTypeDecl *, TypeWitnessAndDecl>
   TypeWitnessMap;
 
 /// Describes the kind of protocol conformance structure used to encode
@@ -157,7 +157,7 @@ class alignas(1 << DeclAlignInBits) ProtocolConformance {
 
   /// Retrieve the type witness and type decl (if one exists)
   /// for the given associated type.
-  std::pair<Type, TypeDecl *>
+  TypeWitnessAndDecl
   getTypeWitnessAndDecl(AssociatedTypeDecl *assocType,
                         SubstOptions options=None) const;
 
@@ -182,7 +182,7 @@ class alignas(1 << DeclAlignInBits) ProtocolConformance {
         continue;
 
       const auto &TWInfo = getTypeWitnessAndDecl(assocTypeReq);
-      if (f(assocTypeReq, TWInfo.first, TWInfo.second))
+      if (f(assocTypeReq, TWInfo.getWitnessType(), TWInfo.getWitnessDecl()))
         return true;
     }
 
@@ -404,6 +404,9 @@ class RootProtocolConformance : public ProtocolConformance {
 class NormalProtocolConformance : public RootProtocolConformance,
                                   public llvm::FoldingSetNode
 {
+  friend class ValueWitnessRequest;
+  friend class TypeWitnessRequest;
+
   /// The protocol being conformed to and its current state.
   llvm::PointerIntPair<ProtocolDecl *, 2, ProtocolConformanceState>
     ProtocolAndState;
@@ -588,10 +591,13 @@ class NormalProtocolConformance : public RootProtocolConformance,
 
   /// Retrieve the type witness and type decl (if one exists)
   /// for the given associated type.
-  std::pair<Type, TypeDecl *>
+  TypeWitnessAndDecl
   getTypeWitnessAndDecl(AssociatedTypeDecl *assocType,
                         SubstOptions options=None) const;
 
+  TypeWitnessAndDecl
+  getTypeWitnessUncached(AssociatedTypeDecl *requirement) const;
+
   /// Determine whether the protocol conformance has a type witness for the
   /// given associated type.
   bool hasTypeWitness(AssociatedTypeDecl *assocType) const;
@@ -610,6 +616,8 @@ class NormalProtocolConformance : public RootProtocolConformance,
   /// Retrieve the value witness corresponding to the given requirement.
   Witness getWitness(ValueDecl *requirement) const;
 
+  Witness getWitnessUncached(ValueDecl *requirement) const;
+
   /// Determine whether the protocol conformance has a witness for the given
   /// requirement.
   bool hasWitness(ValueDecl *requirement) const {
@@ -641,7 +649,7 @@ class NormalProtocolConformance : public RootProtocolConformance,
   /// Determine whether the witness for the given type requirement
   /// is the default definition.
   bool usesDefaultDefinition(AssociatedTypeDecl *requirement) const {
-    TypeDecl *witnessDecl = getTypeWitnessAndDecl(requirement).second;
+    TypeDecl *witnessDecl = getTypeWitnessAndDecl(requirement).getWitnessDecl();
     if (witnessDecl)
       return witnessDecl->isImplicit();
     // Conservatively assume it does not.
@@ -713,7 +721,7 @@ class SelfProtocolConformance : public RootProtocolConformance {
     llvm_unreachable("self-conformances never have associated types");
   }
 
-  std::pair<Type, TypeDecl *>
+  TypeWitnessAndDecl
   getTypeWitnessAndDecl(AssociatedTypeDecl *assocType,
                         SubstOptions options=None) const {
     llvm_unreachable("self-conformances never have associated types");
@@ -859,7 +867,7 @@ class SpecializedProtocolConformance : public ProtocolConformance,
 
   /// Retrieve the type witness and type decl (if one exists)
   /// for the given associated type.
-  std::pair<Type, TypeDecl *>
+  TypeWitnessAndDecl
   getTypeWitnessAndDecl(AssociatedTypeDecl *assocType,
                         SubstOptions options=None) const;
 
@@ -971,7 +979,7 @@ class InheritedProtocolConformance : public ProtocolConformance,
 
   /// Retrieve the type witness and type decl (if one exists)
   /// for the given associated type.
-  std::pair<Type, TypeDecl *>
+  TypeWitnessAndDecl
   getTypeWitnessAndDecl(AssociatedTypeDecl *assocType,
                         SubstOptions options=None) const {
     return InheritedConformance->getTypeWitnessAndDecl(assocType, options);
@@ -1015,6 +1023,8 @@ inline bool ProtocolConformance::hasWitness(ValueDecl *requirement) const {
   return getRootConformance()->hasWitness(requirement);
 }
 
+void simple_display(llvm::raw_ostream &out, const ProtocolConformance *conf);
+
 } // end namespace swift
 
 #endif // LLVM_SWIFT_AST_PROTOCOLCONFORMANCE_H

include/swift/AST/TypeCheckRequests.h

@@ -41,6 +41,8 @@ class RequirementRepr;
 class SpecializeAttr;
 class TypeAliasDecl;
 struct TypeLoc;
+class Witness;
+struct TypeWitnessAndDecl;
 class ValueDecl;
 enum class OpaqueReadOwnership: uint8_t;
 class StorageImplInfo;
@@ -1697,6 +1699,51 @@ class ResolveImplicitMemberRequest
   bool isCached() const { return true; }
 };
 
+class TypeWitnessRequest
+    : public SimpleRequest<TypeWitnessRequest,
+                           TypeWitnessAndDecl(NormalProtocolConformance *,
+                                              AssociatedTypeDecl *),
+                           CacheKind::SeparatelyCached> {
+public:
+  using SimpleRequest::SimpleRequest;
+
+private:
+  friend SimpleRequest;
+
+  // Evaluation.
+  llvm::Expected<TypeWitnessAndDecl>
+  evaluate(Evaluator &evaluator, NormalProtocolConformance *conformance,
+           AssociatedTypeDecl *ATD) const;
+
+public:
+  // Separate caching.
+  bool isCached() const { return true; }
+  Optional<TypeWitnessAndDecl> getCachedResult() const;
+  void cacheResult(TypeWitnessAndDecl value) const;
+};
+
+class ValueWitnessRequest
+    : public SimpleRequest<ValueWitnessRequest,
+                           Witness(NormalProtocolConformance *, ValueDecl *),
+                           CacheKind::SeparatelyCached> {
+public:
+  using SimpleRequest::SimpleRequest;
+
+private:
+  friend SimpleRequest;
+
+  // Evaluation.
+  llvm::Expected<Witness> evaluate(Evaluator &evaluator,
+                                   NormalProtocolConformance *conformance,
+                                   ValueDecl *VD) const;
+
+public:
+  // Separate caching.
+  bool isCached() const { return true; }
+  Optional<Witness> getCachedResult() const;
+  void cacheResult(Witness value) const;
+};
+
 // Allow AnyValue to compare two Type values, even though Type doesn't
 // support ==.
 template<>