[AST] Protocol conformance cleanups

include/swift/AST/ASTContext.h

@@ -662,7 +662,6 @@ class ASTContext {
   /// Produce a new normal conformance for a property behavior.
   NormalProtocolConformance *
   getBehaviorConformance(Type conformingType,
-                         Type conformingInterfaceType,
                          ProtocolDecl *protocol,
                          SourceLoc loc,
                          AbstractStorageDecl *storage,

include/swift/AST/ProtocolConformance.h

@@ -94,14 +94,9 @@ class alignas(1 << DeclAlignInBits) ProtocolConformance {
   /// conformance definition.
   Type ConformingType;
 
-  /// \brief The interface type that conforms to the protocol.
-  Type ConformingInterfaceType;
-
 protected:
-  ProtocolConformance(ProtocolConformanceKind kind, Type conformingType,
-                      Type conformingInterfaceType)
-    : Kind(kind), ConformingType(conformingType),
-      ConformingInterfaceType(conformingInterfaceType) { }
+  ProtocolConformance(ProtocolConformanceKind kind, Type conformingType)
+    : Kind(kind), ConformingType(conformingType) { }
 
 public:
   /// Determine the kind of protocol conformance.
@@ -110,9 +105,6 @@ class alignas(1 << DeclAlignInBits) ProtocolConformance {
   /// Get the conforming type.
   Type getType() const { return ConformingType; }
 
-  /// Get the conforming interface type.
-  Type getInterfaceType() const { return ConformingInterfaceType; }
-
   /// Get the protocol being conformed to.
   ProtocolDecl *getProtocol() const;
 
@@ -190,41 +182,16 @@ class alignas(1 << DeclAlignInBits) ProtocolConformance {
     return false;
   }
 
-  /// Retrieve the non-type witness for the given requirement.
-  Witness getWitness(ValueDecl *requirement, LazyResolver *resolver) const;
+  /// Retrieve the value witness declaration corresponding to the given
+  /// requirement.
+  ValueDecl *getWitnessDecl(ValueDecl *requirement,
+                            LazyResolver *resolver) const;
 
 private:
   /// Determine whether we have a witness for the given requirement.
   bool hasWitness(ValueDecl *requirement) const;
 
 public:
-  /// Apply the given function object to each value witness within this
-  /// protocol conformance.
-  ///
-  /// The function object should accept a \c ValueDecl* for the requirement
-  /// followed by the \c Witness for the witness. Note that a generic
-  /// witness will only be specialized if the conformance came from the current
-  /// file.
-  template<typename F>
-  void forEachValueWitness(LazyResolver *resolver, F f) const {
-    const ProtocolDecl *protocol = getProtocol();
-    for (auto req : protocol->getMembers()) {
-      auto valueReq = dyn_cast<ValueDecl>(req);
-      if (!valueReq || isa<AssociatedTypeDecl>(valueReq) ||
-          valueReq->isInvalid())
-        continue;
-
-      if (!valueReq->isProtocolRequirement())
-        continue;
-
-      // If we don't have and cannot resolve witnesses, skip it.
-      if (!resolver && !hasWitness(valueReq))
-        continue;
-
-      f(valueReq, getWitness(valueReq, resolver));
-    }
-  }
-
   /// Retrieve the protocol conformance for the inherited protocol.
   ProtocolConformance *getInheritedConformance(ProtocolDecl *protocol) const;
 
@@ -357,21 +324,16 @@ class NormalProtocolConformance : public ProtocolConformance,
   NormalProtocolConformance(Type conformingType, ProtocolDecl *protocol,
                             SourceLoc loc, DeclContext *dc,
                             ProtocolConformanceState state)
-    : ProtocolConformance(ProtocolConformanceKind::Normal, conformingType,
-                          // FIXME: interface type should be passed in
-                          dc->getDeclaredInterfaceType()),
+    : ProtocolConformance(ProtocolConformanceKind::Normal, conformingType),
       ProtocolAndState(protocol, state), Loc(loc), ContextAndInvalid(dc, false)
   {
   }
 
   NormalProtocolConformance(Type conformingType,
-                            Type conformingInterfaceType,
                             ProtocolDecl *protocol,
                             SourceLoc loc, AbstractStorageDecl *behaviorStorage,
                             ProtocolConformanceState state)
-    : ProtocolConformance(ProtocolConformanceKind::Normal, conformingType,
-                          // FIXME: interface type should be passed in
-                          conformingInterfaceType),
+    : ProtocolConformance(ProtocolConformanceKind::Normal, conformingType),
       ProtocolAndState(protocol, state), Loc(loc),
       ContextAndInvalid(behaviorStorage, false)
   {
@@ -457,11 +419,6 @@ class NormalProtocolConformance : public ProtocolConformance,
                            LazyResolver *resolver = nullptr) const;
 
   /// Retrieve the value witness corresponding to the given requirement.
-  ///
-  /// Note that a generic witness will only be specialized if the conformance
-  /// came from the current file.
-  ///
-  /// FIXME: The 'only specialized if from the same file' bit is awful.
   Witness getWitness(ValueDecl *requirement, LazyResolver *resolver) const;
 
   /// Determine whether the protocol conformance has a witness for the given
@@ -475,6 +432,33 @@ class NormalProtocolConformance : public ProtocolConformance,
   /// Set the witness for the given requirement.
   void setWitness(ValueDecl *requirement, Witness witness) const;
 
+  /// Apply the given function object to each value witness within this
+  /// protocol conformance.
+  ///
+  /// The function object should accept a \c ValueDecl* for the requirement
+  /// followed by the \c Witness for the witness. Note that a generic
+  /// witness will only be specialized if the conformance came from the current
+  /// file.
+  template<typename F>
+  void forEachValueWitness(LazyResolver *resolver, F f) const {
+    const ProtocolDecl *protocol = getProtocol();
+    for (auto req : protocol->getMembers()) {
+      auto valueReq = dyn_cast<ValueDecl>(req);
+      if (!valueReq || isa<AssociatedTypeDecl>(valueReq) ||
+          valueReq->isInvalid())
+        continue;
+
+      if (!valueReq->isProtocolRequirement())
+        continue;
+
+      // If we don't have and cannot resolve witnesses, skip it.
+      if (!resolver && !hasWitness(valueReq))
+        continue;
+
+      f(valueReq, getWitness(valueReq, resolver));
+    }
+  }
+
   /// Retrieve the protocol conformances that satisfy the requirements of the
   /// protocol, which line up with the conformance constraints in the
   /// protocol's requirement signature.
@@ -583,10 +567,6 @@ class SpecializedProtocolConformance : public ProtocolConformance,
   getTypeWitnessAndDecl(AssociatedTypeDecl *assocType,
                         LazyResolver *resolver) const;
 
-  /// Retrieve the value witness corresponding to the given requirement.
-  Witness getWitness(ValueDecl *requirement, LazyResolver *resolver) const;
-
-
   /// Given that the requirement signature of the protocol directly states
   /// that the given dependent type must conform to the given protocol,
   /// return its associated conformance.
@@ -601,17 +581,16 @@ class SpecializedProtocolConformance : public ProtocolConformance,
   }
 
   void Profile(llvm::FoldingSetNodeID &ID) {
-    Profile(ID, getType(), getGenericConformance());
+    Profile(ID, getType(), getGenericConformance(),
+            getGenericSubstitutions());
   }
 
   static void Profile(llvm::FoldingSetNodeID &ID, Type type,
-                      ProtocolConformance *genericConformance) {
-    // FIXME: Consider profiling substitutions here. They could differ in
-    // some crazy cases that also require major diagnostic work, where the
-    // substitutions involve conformances of the same type to the same
-    // protocol drawn from different imported modules.
+                      ProtocolConformance *genericConformance,
+                      SubstitutionList subs) {
     ID.AddPointer(type.getPointer());
     ID.AddPointer(genericConformance);
+    profileSubstitutionList(ID, subs);
   }
 
   static bool classof(const ProtocolConformance *conformance) {
@@ -640,9 +619,7 @@ class InheritedProtocolConformance : public ProtocolConformance,
 
   InheritedProtocolConformance(Type conformingType,
                                ProtocolConformance *inheritedConformance)
-    : ProtocolConformance(ProtocolConformanceKind::Inherited, conformingType,
-            // FIXME: interface type should be passed in
-            inheritedConformance->getDeclContext()->getDeclaredInterfaceType()),
+    : ProtocolConformance(ProtocolConformanceKind::Inherited, conformingType),
       InheritedConformance(inheritedConformance)
   {
   }
@@ -686,12 +663,6 @@ class InheritedProtocolConformance : public ProtocolConformance,
     return InheritedConformance->getTypeWitnessAndDecl(assocType, resolver);
   }
 
-  /// Retrieve the value witness corresponding to the given requirement.
-  Witness getWitness(ValueDecl *requirement, LazyResolver *resolver) const {
-    // FIXME: Substitute!
-    return InheritedConformance->getWitness(requirement, resolver);
-  }
-
   /// Given that the requirement signature of the protocol directly states
   /// that the given dependent type must conform to the given protocol,
   /// return its associated conformance.

include/swift/AST/SubstitutionList.h

@@ -21,6 +21,11 @@
 
 #include "swift/AST/Substitution.h"
 #include "llvm/ADT/ArrayRef.h"
+#include "llvm/ADT/FoldingSet.h"
+
+namespace llvm {
+class FoldingSetNodeID;
+} // end namespace llvm
 
 namespace swift {
 
@@ -41,6 +46,10 @@ void dump(SubstitutionList subs);
 SubstitutionList
 getCanonicalSubstitutionList(SubstitutionList subs,
                              SmallVectorImpl<Substitution> &canSubs);
+
+/// Profile the substitution list for use in a folding set.
+void profileSubstitutionList(llvm::FoldingSetNodeID &id, SubstitutionList subs);
+
 } // end namespace swift
 
 #endif

lib/AST/ASTContext.cpp

@@ -1476,16 +1476,14 @@ void ValueDecl::setLocalDiscriminator(unsigned index) {
 
 NormalProtocolConformance *
 ASTContext::getBehaviorConformance(Type conformingType,
-                                   Type conformingInterfaceType,
                                    ProtocolDecl *protocol,
                                    SourceLoc loc,
                                    AbstractStorageDecl *storage,
                                    ProtocolConformanceState state) {
   auto conformance = new (*this, AllocationArena::Permanent)
-    NormalProtocolConformance(conformingType, conformingInterfaceType,
-                              protocol, loc, storage, state);
+    NormalProtocolConformance(conformingType, protocol, loc, storage, state);
 
-  if (auto nominal = conformingInterfaceType->getAnyNominal()) {
+  if (auto nominal = conformingType->getRValueInstanceType()->getAnyNominal()) {
     // Note: this is an egregious hack. The conformances need to be associated
     // with the actual storage declarations.
     SmallVector<ProtocolConformance *, 2> conformances;
@@ -1528,7 +1526,7 @@ ASTContext::getSpecializedConformance(Type type,
                                       ProtocolConformance *generic,
                                       SubstitutionList substitutions) {
   llvm::FoldingSetNodeID id;
-  SpecializedProtocolConformance::Profile(id, type, generic);
+  SpecializedProtocolConformance::Profile(id, type, generic, substitutions);
 
   // Figure out which arena this conformance should go into.
   AllocationArena arena = getArena(type->getRecursiveProperties());

lib/AST/ASTMangler.cpp

@@ -1839,7 +1839,10 @@ void ASTMangler::appendProtocolConformance(const ProtocolConformance *conformanc
     appendProtocolName(conformance->getProtocol());
     appendIdentifier(behaviorStorage->getName().str());
   } else {
-    appendType(conformance->getInterfaceType()->getCanonicalType());
+    auto conformanceDC = conformance->getDeclContext();
+    auto conformingType =
+      conformanceDC->mapTypeOutOfContext(conformance->getType());
+    appendType(conformingType->getCanonicalType());
     appendProtocolName(conformance->getProtocol());
     appendModule(conformance->getDeclContext()->getParentModule());
   }

lib/AST/ConformanceLookupTable.cpp

@@ -1103,7 +1103,8 @@ ConformanceLookupTable::getSatisfiedProtocolRequirementsForMember(
       if (conf->isInvalid())
         continue;
 
-      conf->forEachValueWitness(resolver, [&](ValueDecl *req,
+      auto normal = conf->getRootNormalConformance();
+      normal->forEachValueWitness(resolver, [&](ValueDecl *req,
                                               ConcreteDeclRef witness) {
         if (witness.getDecl() == member)
           reqs.push_back(req);

lib/AST/ProtocolConformance.cpp

@@ -251,9 +251,22 @@ Type ProtocolConformance::getTypeWitness(AssociatedTypeDecl *assocType,
   return getTypeWitnessAndDecl(assocType, resolver).first;
 }
 
-Witness ProtocolConformance::getWitness(ValueDecl *requirement,
-                                        LazyResolver *resolver) const {
-  CONFORMANCE_SUBCLASS_DISPATCH(getWitness, (requirement, resolver))
+ValueDecl *ProtocolConformance::getWitnessDecl(ValueDecl *requirement,
+                                               LazyResolver *resolver) const {
+  switch (getKind()) {
+  case ProtocolConformanceKind::Normal:
+    return cast<NormalProtocolConformance>(this)->getWitness(requirement,
+                                                             resolver)
+      .getDecl();
+
+  case ProtocolConformanceKind::Inherited:
+    return cast<InheritedProtocolConformance>(this)
+      ->getInheritedConformance()->getWitnessDecl(requirement, resolver);
+
+  case ProtocolConformanceKind::Specialized:
+    return cast<SpecializedProtocolConformance>(this)
+      ->getGenericConformance()->getWitnessDecl(requirement, resolver);
+  }
 }
 
 /// Determine whether the witness for the given requirement
@@ -266,7 +279,7 @@ usesDefaultDefinition(AssociatedTypeDecl *requirement) const {
 bool ProtocolConformance::hasFixedLayout() const {
   // A conformance/witness table has fixed layout if type has a fixed layout in
   // all resilience domains, and the conformance is externally visible.
-  if (auto nominal = getInterfaceType()->getAnyNominal())
+  if (auto nominal = getType()->getAnyNominal())
     if (nominal->hasFixedLayout() &&
         getProtocol()->getEffectiveAccess() >= Accessibility::Public &&
         nominal->getEffectiveAccess() >= Accessibility::Public)
@@ -652,11 +665,7 @@ SpecializedProtocolConformance::SpecializedProtocolConformance(
     Type conformingType,
     ProtocolConformance *genericConformance,
     SubstitutionList substitutions)
-  : ProtocolConformance(ProtocolConformanceKind::Specialized, conformingType,
-                        // FIXME: interface type should be passed in.
-                        // assumes specialized conformance is always fully
-                        // specialized
-                        conformingType),
+  : ProtocolConformance(ProtocolConformanceKind::Specialized, conformingType),
     GenericConformance(genericConformance),
     GenericSubstitutions(substitutions)
 {
@@ -708,13 +717,6 @@ SpecializedProtocolConformance::getTypeWitnessAndDecl(
   return TypeWitnesses[assocType];
 }
 
-Witness
-SpecializedProtocolConformance::getWitness(ValueDecl *requirement,
-                                           LazyResolver *resolver) const {
-  // FIXME: Apply substitutions here!
-  return GenericConformance->getWitness(requirement, resolver);
-}
-
 ProtocolConformanceRef
 SpecializedProtocolConformance::getAssociatedConformance(Type assocType,
                                                 ProtocolDecl *protocol,
@@ -1068,8 +1070,6 @@ bool ProtocolConformance::isCanonical() const {
 
   if (!getType()->isCanonical())
     return false;
-  if (!getInterfaceType()->isCanonical())
-    return false;
 
   switch (getKind()) {
   case ProtocolConformanceKind::Normal: {

lib/AST/SubstitutionList.cpp

@@ -17,5 +17,17 @@
 //===----------------------------------------------------------------------===//
 
 #include "swift/AST/SubstitutionList.h"
+#include "swift/AST/ProtocolConformanceRef.h"
+#include "llvm/ADT/FoldingSet.h"
 
 using namespace swift;
+
+void swift::profileSubstitutionList(llvm::FoldingSetNodeID &id,
+                                    SubstitutionList subs) {
+  id.AddInteger(subs.size());
+  for (auto &sub : subs) {
+    id.AddPointer(sub.getReplacement().getPointer());
+    for (auto conformance : sub.getConformances())
+      id.AddPointer(conformance.getOpaqueValue());
+  }
+}

lib/AST/Type.cpp

@@ -4060,11 +4060,7 @@ bool TypeBase::usesNativeReferenceCounting(ResilienceExpansion resilience) {
 void SILBoxType::Profile(llvm::FoldingSetNodeID &id, SILLayout *Layout,
                          SubstitutionList Args) {
   id.AddPointer(Layout);
-  for (auto &arg : Args) {
-    id.AddPointer(arg.getReplacement().getPointer());
-    for (auto conformance : arg.getConformances())
-      id.AddPointer(conformance.getOpaqueValue());
-  }
+  profileSubstitutionList(id, Args);
 }
 
 SILBoxType::SILBoxType(ASTContext &C,

lib/IRGen/GenReflection.cpp

@@ -283,7 +283,7 @@ class AssociatedTypeMetadataBuilder : public ReflectionMetadataBuilder {
   void layout() override {
     // If the conforming type is generic, we just want to emit the
     // unbound generic type here.
-    auto *Nominal = Conformance->getInterfaceType()->getAnyNominal();
+    auto *Nominal = Conformance->getType()->getAnyNominal();
     assert(Nominal && "Structural conformance?");
 
     PrettyStackTraceDecl DebugStack("emitting associated type metadata",