Merge pull request #80225 from DougGregor/conforming-type-in-abstract-conformance

Store the conforming type within an abstract ProtocolConformanceRef

Author: DougGregor

include/swift/AST/ASTBridgingImpl.h

@@ -602,7 +602,7 @@ BridgedASTType BridgedConformance::getType() const {
 }
 
 BridgedDeclObj BridgedConformance::getRequirement() const {
-  return {unbridged().getRequirement()};
+  return {unbridged().getProtocol()};
 }
 
 BridgedConformance BridgedConformance::getGenericConformance() const {

include/swift/AST/ProtocolConformanceRef.h

@@ -26,8 +26,24 @@
 #include "llvm/ADT/STLExtras.h"
 #include <optional>
 
+namespace swift {
+class AbstractConformance;
+}
+
 namespace llvm {
-  class raw_ostream;
+class raw_ostream;
+
+template <>
+struct PointerLikeTypeTraits<swift::AbstractConformance *> {
+public:
+  static inline void *getAsVoidPointer(swift::AbstractConformance *ptr) {
+    return ptr;
+  }
+  static inline swift::AbstractConformance *getFromVoidPointer(void *ptr) {
+    return (swift::AbstractConformance *)ptr;
+  }
+  enum { NumLowBitsAvailable = swift::TypeAlignInBits };
+};
 }
 
 namespace swift {
@@ -53,22 +69,27 @@ enum class EffectKind : uint8_t;
 /// ProtocolConformanceRef allows the efficient recovery of the protocol
 /// even when the conformance is abstract.
 class ProtocolConformanceRef {
-  using UnionType = llvm::PointerUnion<ProtocolDecl *,
+public:
+  using UnionType = llvm::PointerUnion<AbstractConformance *,
                                        ProtocolConformance *,
                                        PackConformance *>;
+
+private:
   UnionType Union;
 
   explicit ProtocolConformanceRef(UnionType value) : Union(value) {}
 
+public:
+  ProtocolConformanceRef() : Union() {}
+  ProtocolConformanceRef(std::nullptr_t) : Union() {}
+
   /// Create an abstract protocol conformance reference.
-  explicit ProtocolConformanceRef(ProtocolDecl *proto) : Union(proto) {
-    assert(proto != nullptr &&
+  explicit ProtocolConformanceRef(AbstractConformance *abstract)
+      : Union(abstract) {
+    assert(abstract != nullptr &&
            "cannot construct ProtocolConformanceRef with null");
   }
 
-public:
-  ProtocolConformanceRef() : Union() {}
-
   /// Create a concrete protocol conformance reference.
   explicit ProtocolConformanceRef(ProtocolConformance *conf) : Union(conf) {
     assert(conf != nullptr &&
@@ -95,7 +116,7 @@ class ProtocolConformanceRef {
   explicit operator bool() const { return !isInvalid(); }
 
   /// Create an abstract conformance for a type parameter or archetype.
-  static ProtocolConformanceRef forAbstract(Type subjectType,
+  static ProtocolConformanceRef forAbstract(Type conformingType,
                                             ProtocolDecl *protocol);
 
   bool isConcrete() const {
@@ -115,12 +136,11 @@ class ProtocolConformanceRef {
   }
 
   bool isAbstract() const {
-    return !isInvalid() && Union.is<ProtocolDecl*>();
+    return !isInvalid() && Union.is<AbstractConformance*>();
   }
 
-  ProtocolDecl *getAbstract() const {
-    ASSERT(isAbstract());
-    return Union.get<ProtocolDecl*>();
+  AbstractConformance *getAbstract() const {
+    return Union.get<AbstractConformance *>();
   }
 
   /// Determine whether this conformance (or a conformance it depends on)
@@ -149,7 +169,7 @@ class ProtocolConformanceRef {
   /// The given `body` will be called on each isolated conformance. If it ever
   /// returns `true`, this function will abort the search and return `true`.
   bool forEachIsolatedConformance(
-      llvm::function_ref<bool(ProtocolConformance*)> body
+      llvm::function_ref<bool(ProtocolConformanceRef)> body
   ) const;
 
   using OpaqueValue = void*;
@@ -158,8 +178,11 @@ class ProtocolConformanceRef {
     return ProtocolConformanceRef(UnionType::getFromOpaqueValue(value));
   }
 
+  /// Retrieve the conforming type.
+  Type getType() const;
+
   /// Return the protocol requirement.
-  ProtocolDecl *getRequirement() const;
+  ProtocolDecl *getProtocol() const;
 
   /// Apply a substitution to the conforming type.
   ProtocolConformanceRef subst(Type origType, SubstitutionMap subMap,
@@ -240,4 +263,22 @@ SourceLoc extractNearestSourceLoc(const ProtocolConformanceRef conformanceRef);
 
 } // end namespace swift
 
+namespace llvm {
+class raw_ostream;
+
+template <>
+struct PointerLikeTypeTraits<swift::ProtocolConformanceRef>
+  : PointerLikeTypeTraits<swift::ProtocolConformanceRef::UnionType>
+{
+public:
+  static inline void *getAsVoidPointer(swift::ProtocolConformanceRef ref) {
+    return ref.getOpaqueValue();
+  }
+  static inline swift::ProtocolConformanceRef getFromVoidPointer(void *ptr) {
+    return swift::ProtocolConformanceRef::getFromOpaqueValue(ptr);
+  }
+};
+
+}
+
 #endif // LLVM_SWIFT_AST_PROTOCOLCONFORMANCEREF_H

include/swift/AST/Requirement.h

@@ -192,7 +192,7 @@ class Requirement {
   CheckRequirementResult checkRequirement(
       SmallVectorImpl<Requirement> &subReqs,
       bool allowMissing = false,
-      SmallVectorImpl<ProtocolConformance *> *isolatedConformances = nullptr
+      SmallVectorImpl<ProtocolConformanceRef> *isolatedConformances = nullptr
   ) const;
 
   /// Determines if this substituted requirement can ever be satisfied,

lib/APIDigester/ModuleAnalyzerNodes.cpp

@@ -1498,7 +1498,7 @@ SDKNodeInitInfo::SDKNodeInitInfo(SDKContext &Ctx, ImportDecl *ID):
 }
 
 SDKNodeInitInfo::SDKNodeInitInfo(SDKContext &Ctx, ProtocolConformanceRef Conform):
-    SDKNodeInitInfo(Ctx, Conform.getRequirement()) {
+    SDKNodeInitInfo(Ctx, Conform.getProtocol()) {
   // The conformance can be conditional. The generic signature keeps track of
   // the requirements.
   if (Conform.isConcrete()) {

lib/AST/ASTContext.cpp

@@ -15,6 +15,7 @@
 //===----------------------------------------------------------------------===//
 
 #include "swift/AST/ASTContext.h"
+#include "AbstractConformance.h"
 #include "ClangTypeConverter.h"
 #include "ForeignRepresentationInfo.h"
 #include "SubstitutionMapStorage.h"
@@ -596,6 +597,9 @@ struct ASTContext::Implementation {
     /// The set of substitution maps (uniqued by their storage).
     llvm::FoldingSet<SubstitutionMap::Storage> SubstitutionMaps;
 
+    /// The set of abstract conformances (uniqued by their storage).
+    llvm::FoldingSet<AbstractConformance> AbstractConformances;
+
     ~Arena() {
       for (auto &conformance : SpecializedConformances)
         conformance.~SpecializedProtocolConformance();
@@ -3379,6 +3383,7 @@ void ASTContext::Implementation::Arena::dump(llvm::raw_ostream &os) const {
     SIZE_AND_BYTES(BuiltinConformances);
     SIZE(PackConformances);
     SIZE(SubstitutionMaps);
+    SIZE(AbstractConformances);
 
 #undef SIZE
 #undef SIZE_AND_BYTES
@@ -5104,7 +5109,7 @@ void SILFunctionType::Profile(
   invocationSubs.profile(id);
   id.AddBoolean((bool)conformance);
   if (conformance)
-    id.AddPointer(conformance.getRequirement());
+    id.AddPointer(conformance.getProtocol());
 }
 
 SILFunctionType::SILFunctionType(
@@ -5739,6 +5744,35 @@ SubstitutionMap::Storage *SubstitutionMap::Storage::get(
   return result;
 }
 
+ProtocolConformanceRef ProtocolConformanceRef::forAbstract(
+    Type conformingType, ProtocolDecl *proto) {
+  ASTContext &ctx = proto->getASTContext();
+
+  // Figure out which arena this should go in.
+  RecursiveTypeProperties properties;
+  if (conformingType)
+    properties |= conformingType->getRecursiveProperties();
+  auto arena = getArena(properties);
+
+  // Profile the substitution map.
+  llvm::FoldingSetNodeID id;
+  AbstractConformance::Profile(id, conformingType, proto);
+
+  // Did we already record this abstract conformance?
+  void *insertPos;
+  auto &abstractConformances =
+      ctx.getImpl().getArena(arena).AbstractConformances;
+  if (auto result = abstractConformances.FindNodeOrInsertPos(id, insertPos))
+    return ProtocolConformanceRef(result);
+
+  // Allocate and record this abstract conformance.
+  auto mem = ctx.Allocate(sizeof(AbstractConformance),
+                          alignof(AbstractConformance), arena);
+  auto result = new (mem) AbstractConformance(conformingType, proto);
+  abstractConformances.InsertNode(result, insertPos);
+  return ProtocolConformanceRef(result);
+}
+
 const AvailabilityContext::Storage *AvailabilityContext::Storage::get(
     const AvailabilityRange &platformRange, bool isDeprecated,
     llvm::ArrayRef<DomainInfo> domainInfos, const ASTContext &ctx) {

lib/AST/ASTDumper.cpp

@@ -5519,7 +5519,7 @@ class PrintConformance : public PrintBase {
       assert(conformance.isAbstract());
 
       printHead("abstract_conformance", ASTNodeColor, label);
-      printReferencedDeclField(conformance.getAbstract(),
+      printReferencedDeclField(conformance.getProtocol(),
                                Label::always("protocol"));
       printFoot();
     }

lib/AST/ASTMangler.cpp

@@ -2170,7 +2170,7 @@ void ASTMangler::appendRetroactiveConformances(SubstitutionMap subMap,
     if (conformance.isInvalid())
       continue;
 
-    if (conformance.getRequirement()->isMarkerProtocol())
+    if (conformance.getProtocol()->isMarkerProtocol())
       continue;
 
     SWIFT_DEFER {
@@ -4528,7 +4528,7 @@ void ASTMangler::appendAnyProtocolConformance(
   // If we have a conformance to a marker protocol but we aren't allowed to
   // emit marker protocols, skip it.
   if (!AllowMarkerProtocols &&
-      conformance.getRequirement()->isMarkerProtocol())
+      conformance.getProtocol()->isMarkerProtocol())
     return;
 
   // While all invertible protocols are marker protocols, do not mangle them
@@ -4537,15 +4537,17 @@ void ASTMangler::appendAnyProtocolConformance(
   // but we *might* have let that slip by for the other cases below, so the
   // early-exits are highly conservative.
   const bool forInvertible =
-      conformance.getRequirement()->getInvertibleProtocolKind().has_value();
+      conformance.getProtocol()->getInvertibleProtocolKind().has_value();
 
   if (conformingType->isTypeParameter()) {
     assert(genericSig && "Need a generic signature to resolve conformance");
     if (forInvertible)
       return;
 
+    // FIXME: conformingType parameter should no longer be needed, because
+    // its in conformance.
     auto path = genericSig->getConformancePath(conformingType,
-                                               conformance.getAbstract());
+                                               conformance.getProtocol());
     appendDependentProtocolConformance(path, genericSig);
   } else if (auto opaqueType = conformingType->getAs<OpaqueTypeArchetypeType>()) {
     if (forInvertible)
@@ -4556,7 +4558,7 @@ void ASTMangler::appendAnyProtocolConformance(
     ConformancePath conformancePath =
         opaqueSignature->getConformancePath(
           opaqueType->getInterfaceType(),
-          conformance.getAbstract());
+          conformance.getProtocol());
 
     // Append the conformance path with the signature of the opaque type.
     appendDependentProtocolConformance(conformancePath, opaqueSignature);

lib/AST/ASTPrinter.cpp

@@ -6634,7 +6634,7 @@ class TypePrinter : public TypeVisitor<TypePrinter> {
       case SILFunctionType::Representation::WitnessMethod:
         Printer << "witness_method: ";
         printTypeDeclName(
-            witnessMethodConformance.getRequirement()->getDeclaredType()
+            witnessMethodConformance.getProtocol()->getDeclaredType()
                 ->castTo<ProtocolType>());
         break;
       case SILFunctionType::Representation::Closure:

lib/AST/ASTVerifier.cpp

@@ -1785,7 +1785,7 @@ class Verifier : public ASTWalker {
         for (auto proto : erasedLayout.getProtocols()) {
           if (std::find_if(conformances.begin(), conformances.end(),
                            [&](ProtocolConformanceRef ref) -> bool {
-                             return ref.getRequirement() == proto->getDecl();
+                             return ref.getProtocol() == proto->getDecl();
                            })
               == conformances.end()) {
             Out << "ErasureExpr is missing conformance for required protocol\n";
@@ -1819,7 +1819,7 @@ class Verifier : public ASTWalker {
                     anyHashableDecl->getDeclaredInterfaceType(),
                     "AnyHashableErasureExpr and the standard AnyHashable type");
 
-      if (E->getConformance().getRequirement() != hashableDecl) {
+      if (E->getConformance().getProtocol() != hashableDecl) {
         Out << "conformance on AnyHashableErasureExpr was not for Hashable\n";
         E->getConformance().dump(Out);
         abort();
@@ -2811,7 +2811,7 @@ class Verifier : public ASTWalker {
         if (!type->is<ArchetypeType>() && !type->isAnyExistentialType()) {
           Out << "type " << type
               << " should not have an abstract conformance to "
-              << conformance.getRequirement()->getName();
+              << conformance.getProtocol()->getName();
           abort();
         }
 

lib/AST/AbstractConformance.h

@@ -0,0 +1,51 @@
+//===--- AbstractConformance.h - Abstract conformance storage ---*- C++ -*-===//
+//
+// This source file is part of the Swift.org open source project
+//
+// Copyright (c) 2014 - 2017 Apple Inc. and the Swift project authors
+// Licensed under Apache License v2.0 with Runtime Library Exception
+//
+// See https://swift.org/LICENSE.txt for license information
+// See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
+//
+//===----------------------------------------------------------------------===//
+//
+// This file defines the AbstractConformance class, which stores an
+// abstract conformance that is stashed in a ProtocolConformanceRef.
+//
+//===----------------------------------------------------------------------===//
+#ifndef SWIFT_AST_ABSTRACT_CONFORMANCE_H
+#define SWIFT_AST_ABSTRACT_CONFORMANCE_H
+
+#include "swift/AST/Type.h"
+#include "llvm/ADT/FoldingSet.h"
+
+namespace swift {
+class AbstractConformance final : public llvm::FoldingSetNode {
+  Type conformingType;
+  ProtocolDecl *requirement;
+
+public:
+  AbstractConformance(Type conformingType, ProtocolDecl *requirement)
+    : conformingType(conformingType), requirement(requirement) { }
+
+  Type getType() const { return conformingType; }
+  ProtocolDecl *getProtocol() const { return requirement; }
+
+  void Profile(llvm::FoldingSetNodeID &id) const {
+    Profile(id, getType(), getProtocol());
+  }
+
+  /// Profile the substitution map storage, for use with LLVM's FoldingSet.
+  static void Profile(llvm::FoldingSetNodeID &id,
+                      Type conformingType,
+                      ProtocolDecl *requirement) {
+    id.AddPointer(conformingType.getPointer());
+    id.AddPointer(requirement);
+  }
+};
+
+}
+
+#endif // SWIFT_AST_ABSTRACT_CONFORMANCE_H
+