Merge pull request swiftlang#81142 from slavapestov/more-type-subst-cleanup

Clean up duplicated opened existential archetype handling in SIL and more

Author: slavapestov

SwiftCompilerSources/Sources/AST/Type.swift

@@ -64,10 +64,6 @@ public struct Type: TypeProperties, CustomStringConvertible, NoReflectionChildre
   public func subst(with substitutionMap: SubstitutionMap) -> Type {
     return Type(bridged: bridged.subst(substitutionMap.bridged))
   }
-
-  public func subst(type: Type, with targetType: Type) -> Type {
-    return Type(bridged: bridged.subst(type.bridged, targetType.bridged))
-  }
 }
 
 /// A Type that is statically known to be canonical.
@@ -88,10 +84,6 @@ public struct CanonicalType: TypeProperties, CustomStringConvertible, NoReflecti
   public func subst(with substitutionMap: SubstitutionMap) -> CanonicalType {
     return rawType.subst(with: substitutionMap).canonical
   }
-
-  public func subst(type: CanonicalType, with targetType: CanonicalType) -> CanonicalType {
-    return self.rawType.subst(type: type.rawType, with: targetType.rawType).canonical
-  }
 }
 
 /// Implements the common members of `AST.Type`, `AST.CanonicalType` and `SIL.Type`.

include/swift/AST/ASTBridging.h

@@ -3115,7 +3115,6 @@ struct BridgedASTType {
   SWIFT_IMPORT_UNSAFE BRIDGED_INLINE BridgedSubstitutionMap getContextSubstitutionMap() const;
   SWIFT_IMPORT_UNSAFE BRIDGED_INLINE BridgedGenericSignature getInvocationGenericSignatureOfFunctionType() const;
   SWIFT_IMPORT_UNSAFE BRIDGED_INLINE BridgedASTType subst(BridgedSubstitutionMap substMap) const;
-  SWIFT_IMPORT_UNSAFE BRIDGED_INLINE BridgedASTType subst(BridgedASTType fromType, BridgedASTType toType) const;
   SWIFT_IMPORT_UNSAFE BRIDGED_INLINE BridgedConformance checkConformance(BridgedDeclObj proto) const;  
 };
 

include/swift/AST/ASTBridgingImpl.h

@@ -596,17 +596,6 @@ BridgedASTType BridgedASTType::subst(BridgedSubstitutionMap substMap) const {
   return {unbridged().subst(substMap.unbridged()).getPointer()};
 }
 
-
-BridgedASTType BridgedASTType::subst(BridgedASTType fromType, BridgedASTType toType) const {
-  auto *fromTy = fromType.unbridged()->castTo<swift::SubstitutableType>();
-  swift::Type toTy = toType.unbridged();
-  return {unbridged().subst([fromTy, toTy](swift::SubstitutableType *t) -> swift::Type {
-    if (t == fromTy)
-      return toTy;
-    return t;
-  }, swift::LookUpConformanceInModule(), swift::SubstFlags::SubstituteLocalArchetypes).getPointer()};
-}
-
 BridgedConformance BridgedASTType::checkConformance(BridgedDeclObj proto) const {
   return swift::checkConformance(unbridged(), proto.getAs<swift::ProtocolDecl>(), /*allowMissing=*/ false);
 }  

include/swift/AST/ASTContext.h

@@ -1051,6 +1051,9 @@ class ASTContext final {
   const CanType TheUnconstrainedAnyType;  /// This is 'any ~Copyable & ~Escapable',
                                           /// the empty protocol composition
                                           /// without any implicit constraints.
+  const CanGenericTypeParamType TheSelfType; /// The protocol 'Self' type;
+                                             /// a generic parameter with
+                                             /// depth 0 index 0
 #define SINGLETON_TYPE(SHORT_ID, ID) \
   const CanType The##SHORT_ID##Type;
 #include "swift/AST/TypeNodes.def"

include/swift/AST/InFlightSubstitution.h

@@ -52,8 +52,7 @@ class InFlightSubstitution {
   Type substType(SubstitutableType *origType, unsigned level);
 
   /// Perform primitive conformance lookup on the given type.
-  ProtocolConformanceRef lookupConformance(CanType dependentType,
-                                           Type conformingReplacementType,
+  ProtocolConformanceRef lookupConformance(Type dependentType,
                                            ProtocolDecl *conformedProtocol,
                                            unsigned level);
 

include/swift/AST/SubstitutionMap.h

@@ -181,12 +181,6 @@ class SubstitutionMap {
   /// subsystem.
   SubstitutionMap subst(InFlightSubstitution &subs) const;
 
-  /// Apply type expansion lowering to all types in the substitution map. Opaque
-  /// archetypes will be lowered to their underlying types if the type expansion
-  /// context allows.
-  SubstitutionMap mapIntoTypeExpansionContext(
-      TypeExpansionContext context) const;
-
   /// Create a substitution map for a protocol conformance.
   static SubstitutionMap
   getProtocolSubstitutions(ProtocolConformanceRef conformance);

include/swift/AST/Types.h

@@ -5032,9 +5032,15 @@ Type substOpaqueTypesWithUnderlyingTypes(Type type,
 
 CanType substOpaqueTypesWithUnderlyingTypes(CanType type,
                                             TypeExpansionContext context);
+
 ProtocolConformanceRef
 substOpaqueTypesWithUnderlyingTypes(ProtocolConformanceRef ref,
                                     TypeExpansionContext context);
+
+SubstitutionMap
+substOpaqueTypesWithUnderlyingTypes(SubstitutionMap subs,
+                                    TypeExpansionContext context);
+
 namespace Lowering {
   class TypeConverter;
 }
@@ -7082,6 +7088,32 @@ class ReplaceOpaqueTypesWithUnderlyingTypes {
   bool isWholeModule() const { return inContextAndIsWholeModule.getInt(); }
 };
 
+/// A function object that can be used as a \c TypeSubstitutionFn and
+/// \c LookupConformanceFn for \c Type::subst style APIs to map existential
+/// archetypes in the given generic environment to known concrete types from
+/// the given substitution map.
+class ReplaceExistentialArchetypesWithConcreteTypes {
+private:
+  GenericEnvironment *env;
+  SubstitutionMap subs;
+
+  Type getInterfaceType(ExistentialArchetypeType *type) const;
+
+public:
+  ReplaceExistentialArchetypesWithConcreteTypes(GenericEnvironment *env,
+                                                SubstitutionMap subs)
+      : env(env), subs(subs) {}
+
+  /// TypeSubstitutionFn
+  Type operator()(SubstitutableType *type) const;
+
+  /// LookupConformanceFn
+  ProtocolConformanceRef operator()(CanType origType,
+                                    Type substType,
+                                    ProtocolDecl *protocol) const;
+
+};
+
 /// An archetype that's only valid in a portion of a local context.
 class LocalArchetypeType : public ArchetypeType {
 protected:

include/swift/SIL/SILCloner.h

@@ -590,7 +590,7 @@ class SILCloner : protected SILInstructionVisitor<ImplClass> {
           !context.shouldLookThroughOpaqueTypeArchetypes())
         return Subs;
 
-      return Subs.mapIntoTypeExpansionContext(context);
+      return substOpaqueTypesWithUnderlyingTypes(Subs, context);
     }
 
     return Subs;

lib/AST/ASTContext.cpp

@@ -817,6 +817,8 @@ ASTContext::ASTContext(
       TheAnyType(ProtocolCompositionType::theAnyType(*this)),
       TheUnconstrainedAnyType(
           ProtocolCompositionType::theUnconstrainedAnyType(*this)),
+      TheSelfType(CanGenericTypeParamType(
+          GenericTypeParamType::getType(0, 0, *this))),
 #define SINGLETON_TYPE(SHORT_ID, ID) \
     The##SHORT_ID##Type(new (*this, AllocationArena::Permanent) \
                           ID##Type(*this)),
@@ -6646,8 +6648,7 @@ CanGenericSignature ASTContext::getSingleGenericParameterSignature() const {
   if (auto theSig = getImpl().SingleGenericParameterSignature)
     return theSig;
 
-  auto param = GenericTypeParamType::getType(/*depth*/ 0, /*index*/ 0, *this);
-  auto sig = GenericSignature::get(param, { });
+  auto sig = GenericSignature::get({TheSelfType}, { });
   auto canonicalSig = CanGenericSignature(sig);
   getImpl().SingleGenericParameterSignature = canonicalSig;
   return canonicalSig;

lib/AST/ASTMangler.cpp

@@ -395,7 +395,7 @@ std::string ASTMangler::mangleKeyPathGetterThunkHelper(
       sub = sub.transformRec([](Type t) -> std::optional<Type> {
         if (auto *openedExistential = t->getAs<ExistentialArchetypeType>()) {
           auto &ctx = openedExistential->getASTContext();
-          return GenericTypeParamType::getType(0, 0, ctx);
+          return ctx.TheSelfType;
         }
         return std::nullopt;
       });
@@ -431,7 +431,7 @@ std::string ASTMangler::mangleKeyPathSetterThunkHelper(
       sub = sub.transformRec([](Type t) -> std::optional<Type> {
         if (auto *openedExistential = t->getAs<ExistentialArchetypeType>()) {
           auto &ctx = openedExistential->getASTContext();
-          return GenericTypeParamType::getType(0, 0, ctx);
+          return ctx.TheSelfType;
         }
         return std::nullopt;
       });
@@ -5274,15 +5274,11 @@ static void extractExistentialInverseRequirements(
 
   auto &ctx = PCT->getASTContext();
 
-  // Form a parameter referring to the existential's Self.
-  auto existentialSelf =
-      GenericTypeParamType::getType(/*depth=*/0, /*index=*/0, ctx);
-
   for (auto ip : PCT->getInverses()) {
     auto *proto = ctx.getProtocol(getKnownProtocolKind(ip));
     assert(proto);
     ASSERT(!getABIDecl(proto) && "can't use @abi on inverse protocols");
-    inverses.push_back({existentialSelf, proto, SourceLoc()});
+    inverses.push_back({ctx.TheSelfType, proto, SourceLoc()});
   }
 }