Merge pull request swiftlang#36721 from CodaFi/resoulver

CodaFi · web-flow · commit a5a79f23c025 · 2021-04-04T23:15:19.000-07:00
[NFC] Move Some Type Resolution Methods from TypeChecker to TypeResolution
diff --git a/lib/Sema/ConstraintSystem.cpp b/lib/Sema/ConstraintSystem.cpp
@@ -702,11 +702,9 @@ Type ConstraintSystem::openUnboundGenericType(
   // pointing at a generic TypeAliasDecl here. If we find a way to
   // handle generic TypeAliases elsewhere, this can just become a
   // call to BoundGenericType::get().
-  return TypeChecker::applyUnboundGenericArguments(
-      decl, parentTy, SourceLoc(),
-      TypeResolution::forContextual(DC, None, /*unboundTyOpener*/ nullptr,
-                                    /*placeholderHandler*/ nullptr),
-      arguments);
+  return TypeResolution::forContextual(DC, None, /*unboundTyOpener*/ nullptr,
+                                       /*placeholderHandler*/ nullptr)
+      .applyUnboundGenericArguments(decl, parentTy, SourceLoc(), arguments);
 }
 
 static void checkNestedTypeConstraints(ConstraintSystem &cs, Type type,
@@ -1291,12 +1289,12 @@ ConstraintSystem::getTypeOfReference(ValueDecl *value,
   // Unqualified reference to a type.
   if (auto typeDecl = dyn_cast<TypeDecl>(value)) {
     // Resolve the reference to this type declaration in our current context.
-    auto type = TypeChecker::resolveTypeInContext(
-        typeDecl, nullptr,
+    auto type =
         TypeResolution::forContextual(useDC, TypeResolverContext::InExpression,
                                       /*unboundTyOpener*/ nullptr,
-                                      /*placeholderHandler*/ nullptr),
-        /*isSpecialized=*/false);
+                                      /*placeholderHandler*/ nullptr)
+            .resolveTypeInContext(typeDecl, /*foundDC*/ nullptr,
+                                  /*isSpecialized=*/false);
 
     checkNestedTypeConstraints(*this, type, locator);
 
diff --git a/lib/Sema/TypeCheckType.cpp b/lib/Sema/TypeCheckType.cpp
@@ -419,16 +419,15 @@ TypeChecker::getDynamicBridgedThroughObjCClass(DeclContext *dc,
   return dc->getASTContext().getBridgedToObjC(dc, valueType);
 }
 
-Type TypeChecker::resolveTypeInContext(TypeDecl *typeDecl, DeclContext *foundDC,
-                                       TypeResolution resolution,
-                                       bool isSpecialized) {
-  auto fromDC = resolution.getDeclContext();
+Type TypeResolution::resolveTypeInContext(TypeDecl *typeDecl,
+                                          DeclContext *foundDC,
+                                          bool isSpecialized) const {
+  auto fromDC = getDeclContext();
   ASTContext &ctx = fromDC->getASTContext();
 
   // If we found a generic parameter, map to the archetype if there is one.
   if (auto genericParam = dyn_cast<GenericTypeParamDecl>(typeDecl)) {
-    return resolution.mapTypeIntoContext(
-        genericParam->getDeclaredInterfaceType());
+    return mapTypeIntoContext(genericParam->getDeclaredInterfaceType());
   }
 
   if (!isSpecialized) {
@@ -440,13 +439,12 @@ Type TypeChecker::resolveTypeInContext(TypeDecl *typeDecl, DeclContext *foundDC,
            parentDC = parentDC->getParent()) {
         auto *parentNominal = parentDC->getSelfNominalTypeDecl();
         if (parentNominal == nominalType)
-          return resolution.mapTypeIntoContext(
-              parentDC->getDeclaredInterfaceType());
+          return mapTypeIntoContext(parentDC->getDeclaredInterfaceType());
         if (isa<ExtensionDecl>(parentDC)) {
           auto *extendedType = parentNominal;
           while (extendedType != nullptr) {
             if (extendedType == nominalType)
-              return resolution.mapTypeIntoContext(
+              return mapTypeIntoContext(
                   extendedType->getDeclaredInterfaceType());
             extendedType = extendedType->getParent()->getSelfNominalTypeDecl();
           }
@@ -466,11 +464,11 @@ Type TypeChecker::resolveTypeInContext(TypeDecl *typeDecl, DeclContext *foundDC,
             if (auto *ugAliasDecl =
                     dyn_cast<TypeAliasDecl>(unboundGeneric->getAnyGeneric())) {
               if (ugAliasDecl == aliasDecl) {
-                if (resolution.getStage() == TypeResolutionStage::Structural &&
+                if (getStage() == TypeResolutionStage::Structural &&
                     aliasDecl->getUnderlyingTypeRepr() != nullptr) {
                   return aliasDecl->getStructuralType();
                 }
-                return resolution.mapTypeIntoContext(
+                return mapTypeIntoContext(
                     aliasDecl->getDeclaredInterfaceType());
               }
 
@@ -481,12 +479,11 @@ Type TypeChecker::resolveTypeInContext(TypeDecl *typeDecl, DeclContext *foundDC,
           if (auto *aliasType =
                   dyn_cast<TypeAliasType>(extendedType.getPointer())) {
             if (aliasType->getDecl() == aliasDecl) {
-              if (resolution.getStage() == TypeResolutionStage::Structural &&
+              if (getStage() == TypeResolutionStage::Structural &&
                   aliasDecl->getUnderlyingTypeRepr() != nullptr) {
                 return aliasDecl->getStructuralType();
               }
-              return resolution.mapTypeIntoContext(
-                  aliasDecl->getDeclaredInterfaceType());
+              return mapTypeIntoContext(aliasDecl->getDeclaredInterfaceType());
             }
             extendedType = aliasType->getParent();
             continue;
@@ -507,12 +504,11 @@ Type TypeChecker::resolveTypeInContext(TypeDecl *typeDecl, DeclContext *foundDC,
         return aliasDecl->getUnboundGenericType();
 
       // Otherwise, return the appropriate type.
-      if (resolution.getStage() == TypeResolutionStage::Structural &&
+      if (getStage() == TypeResolutionStage::Structural &&
           aliasDecl->getUnderlyingTypeRepr() != nullptr) {
         return aliasDecl->getStructuralType();
       }
-      return resolution.mapTypeIntoContext(
-          aliasDecl->getDeclaredInterfaceType());
+      return mapTypeIntoContext(aliasDecl->getDeclaredInterfaceType());
     }
 
     // When a nominal type used outside its context, return the unbound
@@ -539,12 +535,11 @@ Type TypeChecker::resolveTypeInContext(TypeDecl *typeDecl, DeclContext *foundDC,
     if (!foundDC->getDeclaredInterfaceType())
       return ErrorType::get(ctx);
 
-    selfType =
-        resolution.mapTypeIntoContext(foundDC->getDeclaredInterfaceType());
+    selfType = mapTypeIntoContext(foundDC->getDeclaredInterfaceType());
   } else {
     // Otherwise, we want the protocol 'Self' type for
     // substituting into alias types and associated types.
-    selfType = resolution.mapTypeIntoContext(foundDC->getSelfInterfaceType());
+    selfType = mapTypeIntoContext(foundDC->getSelfInterfaceType());
 
     if (selfType->is<GenericTypeParamType>()) {
       if (typeDecl->getDeclContext()->getSelfProtocolDecl()) {
@@ -559,9 +554,9 @@ Type TypeChecker::resolveTypeInContext(TypeDecl *typeDecl, DeclContext *foundDC,
           // because we use the Sequence.SubSequence default instead of
           // the Collection.SubSequence default, even when the conforming
           // type wants to conform to Collection.
-          if (resolution.getStage() == TypeResolutionStage::Structural) {
-            return resolution.resolveSelfAssociatedType(selfType, foundDC,
-                                                        typeDecl->getName());
+          if (getStage() == TypeResolutionStage::Structural) {
+            return resolveSelfAssociatedType(selfType, foundDC,
+                                             typeDecl->getName());
           } else if (auto assocType = dyn_cast<AssociatedTypeDecl>(typeDecl)) {
             typeDecl = assocType->getAssociatedTypeAnchor();
           }
@@ -587,8 +582,8 @@ Type TypeChecker::resolveTypeInContext(TypeDecl *typeDecl, DeclContext *foundDC,
   }
 
   // Finally, substitute the base type into the member type.
-  return substMemberTypeWithBase(fromDC->getParentModule(), typeDecl, selfType,
-                                 resolution.usesArchetypes());
+  return TypeChecker::substMemberTypeWithBase(
+      fromDC->getParentModule(), typeDecl, selfType, usesArchetypes());
 }
 
 static TypeResolutionOptions
@@ -685,7 +680,8 @@ static void diagnoseUnboundGenericType(Type ty, SourceLoc loc);
 /// If the type is itself not generic, this does nothing.
 ///
 /// This function emits diagnostics about an invalid type or the wrong number
-/// of generic arguments, whereas applyUnboundGenericArguments requires this
+/// of generic arguments, whereas
+/// \c TypeResolution::applyUnboundGenericArguments requires this
 /// to be in a correct and valid form.
 ///
 /// \param type The generic type to which to apply arguments.
@@ -697,7 +693,7 @@ static void diagnoseUnboundGenericType(Type ty, SourceLoc loc);
 /// \returns A BoundGenericType bound to the given arguments, or null on
 /// error.
 ///
-/// \see applyUnboundGenericArguments
+/// \see TypeResolution::applyUnboundGenericArguments
 static Type applyGenericArguments(Type type, TypeResolution resolution,
                                   GenericParamList *silParams,
                                   ComponentIdentTypeRepr *comp) {
@@ -831,8 +827,8 @@ static Type applyGenericArguments(Type type, TypeResolution resolution,
     args.push_back(substTy);
   }
 
-  const auto result = TypeChecker::applyUnboundGenericArguments(
-      decl, unboundType->getParent(), loc, resolution, args);
+  const auto result = resolution.applyUnboundGenericArguments(
+      decl, unboundType->getParent(), loc, args);
 
   // Migration hack.
   bool isMutablePointer;
@@ -888,10 +884,9 @@ static Type applyGenericArguments(Type type, TypeResolution resolution,
 }
 
 /// Apply generic arguments to the given type.
-Type TypeChecker::applyUnboundGenericArguments(GenericTypeDecl *decl,
-                                               Type parentTy, SourceLoc loc,
-                                               TypeResolution resolution,
-                                               ArrayRef<Type> genericArgs) {
+Type TypeResolution::applyUnboundGenericArguments(
+    GenericTypeDecl *decl, Type parentTy, SourceLoc loc,
+    ArrayRef<Type> genericArgs) const {
   assert(genericArgs.size() == decl->getGenericParams()->size() &&
          "invalid arguments, use applyGenericArguments for diagnostic emitting");
 
@@ -931,9 +926,7 @@ Type TypeChecker::applyUnboundGenericArguments(GenericTypeDecl *decl,
     auto genericSig = genericEnv->getGenericSignature();
     for (auto gp : genericSig->getGenericParams()) {
       subs[gp->getCanonicalType()->castTo<GenericTypeParamType>()] =
-        (resolution.usesArchetypes()
-         ? genericEnv->mapTypeIntoContext(gp)
-         : gp);
+          (usesArchetypes() ? genericEnv->mapTypeIntoContext(gp) : gp);
     }
   }
 
@@ -957,21 +950,19 @@ Type TypeChecker::applyUnboundGenericArguments(GenericTypeDecl *decl,
 
   // Check the generic arguments against the requirements of the declaration's
   // generic signature.
-  auto dc = resolution.getDeclContext();
-  auto *module = dc->getParentModule();
+  auto *module = getDeclContext()->getParentModule();
 
-  if (!skipRequirementsCheck &&
-      resolution.getStage() > TypeResolutionStage::Structural) {
-    auto result = checkGenericArguments(
-        dc, loc, noteLoc,
-        UnboundGenericType::get(decl, parentTy, dc->getASTContext()),
+  if (!skipRequirementsCheck && getStage() > TypeResolutionStage::Structural) {
+    auto result = TypeChecker::checkGenericArguments(
+        getDeclContext(), loc, noteLoc,
+        UnboundGenericType::get(decl, parentTy, getASTContext()),
         genericSig->getGenericParams(), genericSig->getRequirements(),
         QueryTypeSubstitutionMap{subs});
 
     switch (result) {
     case RequirementCheckResult::Failure:
     case RequirementCheckResult::SubstitutionFailure:
-      return ErrorType::get(dc->getASTContext());
+      return ErrorType::get(getASTContext());
     case RequirementCheckResult::Success:
       break;
     }
@@ -1071,8 +1062,8 @@ static Type resolveTypeDecl(TypeDecl *typeDecl, DeclContext *foundDC,
                             ComponentIdentTypeRepr *comp) {
   // Resolve the type declaration to a specific type. How this occurs
   // depends on the current context and where the type was found.
-  Type type = TypeChecker::resolveTypeInContext(
-      typeDecl, foundDC, resolution, isa<GenericIdentTypeRepr>(comp));
+  Type type = resolution.resolveTypeInContext(typeDecl, foundDC,
+                                              isa<GenericIdentTypeRepr>(comp));
 
   if (type->hasError() && foundDC &&
       (isa<AssociatedTypeDecl>(typeDecl) || isa<TypeAliasDecl>(typeDecl))) {
@@ -3527,9 +3518,8 @@ TypeResolver::resolveDictionaryType(DictionaryTypeRepr *repr,
     return ErrorType::get(getASTContext());
   }
 
-  if (!TypeChecker::applyUnboundGenericArguments(
-          dictDecl, nullptr, repr->getStartLoc(), resolution,
-          {keyTy, valueTy})) {
+  if (!resolution.applyUnboundGenericArguments(
+          dictDecl, nullptr, repr->getStartLoc(), {keyTy, valueTy})) {
     assert(getASTContext().Diags.hadAnyError());
     return ErrorType::get(getASTContext());
   }
diff --git a/lib/Sema/TypeCheckType.h b/lib/Sema/TypeCheckType.h
@@ -407,6 +407,41 @@ class TypeResolution {
   /// Determine whether the given two types are equivalent within this
   /// type resolution context.
   bool areSameType(Type type1, Type type2) const;
+
+  /// Resolve a reference to the given type declaration within a particular
+  /// context.
+  ///
+  /// This routine aids unqualified name lookup for types by performing the
+  /// resolution necessary to rectify the declaration found by name lookup with
+  /// the declaration context from which name lookup started.
+  ///
+  /// \param typeDecl The type declaration found by name lookup.
+  /// \param foundDC The declaration context this type reference was found in.
+  /// \param isSpecialized Whether the type will have generic arguments applied.
+  ///
+  /// \returns the resolved type.
+  Type resolveTypeInContext(TypeDecl *typeDecl, DeclContext *foundDC,
+                            bool isSpecialized) const;
+
+  /// Apply generic arguments to the unbound generic type represented by the
+  /// given declaration and parent type.
+  ///
+  /// This function requires the correct number of generic arguments,
+  /// whereas applyGenericArguments emits diagnostics in those cases.
+  ///
+  /// \param decl The declaration that the resulting bound generic type
+  /// shall reference.
+  /// \param parentTy The parent type.
+  /// \param loc The source location for diagnostic reporting.
+  /// \param genericArgs The list of generic arguments to apply.
+  ///
+  /// \returns A BoundGenericType bound to the given arguments, or null on
+  /// error.
+  ///
+  /// \see applyGenericArguments
+  Type applyUnboundGenericArguments(GenericTypeDecl *decl, Type parentTy,
+                                    SourceLoc loc,
+                                    ArrayRef<Type> genericArgs) const;
 };
 
 } // end namespace swift
diff --git a/lib/Sema/TypeChecker.h b/lib/Sema/TypeChecker.h
@@ -43,7 +43,6 @@ class GenericSignatureBuilder;
 class NominalTypeDecl;
 class NormalProtocolConformance;
 class RootProtocolConformance;
-class TypeResolution;
 class TypeResolutionOptions;
 class TypoCorrectionResults;
 class ExprPattern;
@@ -264,42 +263,6 @@ void checkUnsupportedProtocolType(ASTContext &ctx,
 void checkUnsupportedProtocolType(ASTContext &ctx,
                                   GenericParamList *genericParams);
 
-/// Resolve a reference to the given type declaration within a particular
-/// context.
-///
-/// This routine aids unqualified name lookup for types by performing the
-/// resolution necessary to rectify the declaration found by name lookup with
-/// the declaration context from which name lookup started.
-///
-/// \param typeDecl The type declaration found by name lookup.
-/// \param isSpecialized Whether the type will have generic arguments applied.
-/// \param resolution The resolution to perform.
-///
-/// \returns the resolved type.
-Type resolveTypeInContext(TypeDecl *typeDecl, DeclContext *foundDC,
-                          TypeResolution resolution, bool isSpecialized);
-
-/// Apply generic arguments to the unbound generic type represented by the
-/// given declaration and parent type.
-///
-/// This function requires the correct number of generic arguments,
-/// whereas applyGenericArguments emits diagnostics in those cases.
-///
-/// \param decl The declaration that the resulting bound generic type
-/// shall reference.
-/// \param parentTy The parent type.
-/// \param loc The source location for diagnostic reporting.
-/// \param resolution The type resolution.
-/// \param genericArgs The list of generic arguments to apply.
-///
-/// \returns A BoundGenericType bound to the given arguments, or null on
-/// error.
-///
-/// \see applyGenericArguments
-Type applyUnboundGenericArguments(GenericTypeDecl *decl, Type parentTy,
-                                  SourceLoc loc, TypeResolution resolution,
-                                  ArrayRef<Type> genericArgs);
-
 /// Substitute the given base type into the type of the given nested type,
 /// producing the effective type that the nested type will have.
 ///
