Merge pull request #12327 from slavapestov/more-trivial-cleanups

More trivial cleanups

Author: slavapestov

include/swift/AST/Witness.h

@@ -150,13 +150,6 @@ class Witness {
   /// Determines whether there is a witness at all.
   explicit operator bool() const { return !storage.isNull(); }
 
-  /// Implicit conversion to the \c ConcreteDeclRef, which is used by a
-  /// number of clients.
-  ///
-  /// FIXME: We probably want this to go away eventually, because clients using
-  /// it will all need to be cognizant of the synthetic environment.
-  operator ConcreteDeclRef() const { return getDeclRef(); }
-
   /// Determine whether this witness requires any substitutions.
   bool requiresSubstitution() const { return storage.is<StoredWitness *>(); }
 

lib/AST/ConformanceLookupTable.cpp

@@ -1131,7 +1131,7 @@ ConformanceLookupTable::getSatisfiedProtocolRequirementsForMember(
 
       auto normal = conf->getRootNormalConformance();
       normal->forEachValueWitness(resolver, [&](ValueDecl *req,
-                                              ConcreteDeclRef witness) {
+                                                Witness witness) {
         if (witness.getDecl() == member)
           reqs.push_back(req);
       });

lib/SILGen/SILGenType.cpp

@@ -604,50 +604,30 @@ SILGenModule::emitProtocolWitness(ProtocolConformance *conformance,
                                   Witness witness) {
   auto requirementInfo = Types.getConstantInfo(requirement);
 
+  // Work out the lowered function type of the SIL witness thunk.
+  auto reqtOrigTy = cast<GenericFunctionType>(requirementInfo.LoweredType);
+
   // Mapping from the requirement's generic signature to the witness
   // thunk's generic signature.
-  SubstitutionMap reqtSubMap;
+  auto reqtSubs = witness.getRequirementToSyntheticSubs();
+  auto reqtSubMap = reqtOrigTy->getGenericSignature()->getSubstitutionMap(reqtSubs);
 
   // The generic environment for the witness thunk.
-  GenericEnvironment *genericEnv = nullptr;
+  auto *genericEnv = witness.getSyntheticEnvironment();
+
+  // The type of the witness thunk.
+  auto input = reqtOrigTy->getInput().subst(reqtSubMap)->getCanonicalType();
+  auto result = reqtOrigTy->getResult().subst(reqtSubMap)->getCanonicalType();
 
-  // Work out the lowered function type of the SIL witness thunk.
-  auto reqtOrigTy = cast<GenericFunctionType>(requirementInfo.LoweredType);
   CanAnyFunctionType reqtSubstTy;
-  SubstitutionList witnessSubs;
-  if (witness.requiresSubstitution()) {
-    genericEnv = witness.getSyntheticEnvironment();
-    witnessSubs = witness.getSubstitutions();
-
-    auto reqtSubs = witness.getRequirementToSyntheticSubs();
-    reqtSubMap = reqtOrigTy->getGenericSignature()
-        ->getSubstitutionMap(reqtSubs);
-
-    auto input = reqtOrigTy->getInput().subst(reqtSubMap);
-    auto result = reqtOrigTy->getResult().subst(reqtSubMap);
-
-    if (genericEnv) {
-      auto *genericSig = genericEnv->getGenericSignature();
-      reqtSubstTy = cast<GenericFunctionType>(
-        GenericFunctionType::get(genericSig, input, result,
-                                 reqtOrigTy->getExtInfo())
-          ->getCanonicalType());
-    } else {
-      reqtSubstTy = cast<FunctionType>(
-        FunctionType::get(input, result,
-                          reqtOrigTy->getExtInfo())
-          ->getCanonicalType());
-    }
+  if (genericEnv) {
+    auto *genericSig = genericEnv->getGenericSignature();
+    reqtSubstTy = CanGenericFunctionType::get(
+        genericSig->getCanonicalSignature(),
+        input, result, reqtOrigTy->getExtInfo());
   } else {
-    reqtSubMap = SubstitutionMap::getProtocolSubstitutions(
-        conformance->getProtocol(),
-        conformance->getType(),
-        ProtocolConformanceRef(conformance));
-
-    auto input = reqtOrigTy->getInput().subst(reqtSubMap)->getCanonicalType();
-    auto result = reqtOrigTy->getResult().subst(reqtSubMap)->getCanonicalType();
-
-    reqtSubstTy = CanFunctionType::get(input, result, reqtOrigTy->getExtInfo());
+    reqtSubstTy = CanFunctionType::get(
+        input, result, reqtOrigTy->getExtInfo());
   }
 
   // Lower the witness thunk type with the requirement's abstraction level.
@@ -659,7 +639,7 @@ SILGenModule::emitProtocolWitness(ProtocolConformance *conformance,
   Mangle::ASTMangler NewMangler;
   std::string nameBuffer = NewMangler.mangleWitnessThunk(conformance,
                                                          requirement.getDecl());
-  
+
   // If the thunked-to function is set to be always inlined, do the
   // same with the witness, on the theory that the user wants all
   // calls removed if possible, e.g. when we're able to devirtualize
@@ -694,6 +674,10 @@ SILGenModule::emitProtocolWitness(ProtocolConformance *conformance,
 
   SILGenFunction SGF(*this, *f);
 
+  // Substitutions mapping the generic parameters of the witness to
+  // archetypes of the witness thunk generic environment.
+  auto witnessSubs = witness.getSubstitutions();
+
   // Open-code certain protocol witness "thunks".
   if (maybeOpenCodeProtocolWitness(SGF, conformance, linkage,
                                    selfInterfaceType, selfType, genericEnv,

lib/Sema/TypeCheckProtocol.cpp

@@ -1213,7 +1213,7 @@ matchWitness(TypeChecker &tc,
     if (reqGenericEnv)
       selfTy = reqGenericEnv->mapTypeIntoContext(selfTy);
 
-        // Open up the type of the requirement.
+    // Open up the type of the requirement.
     reqLocator = cs->getConstraintLocator(
                      static_cast<Expr *>(nullptr),
                      LocatorPathElt(ConstraintLocator::Requirement, req));

lib/Serialization/Serialization.cpp

@@ -1642,7 +1642,7 @@ void Serializer::writeDefaultWitnessTable(const ProtocolDecl *proto,
   unsigned abbrCode = abbrCodes[DefaultWitnessTableLayout::Code];
   for (auto member : proto->getMembers()) {
     if (auto *value = dyn_cast<ValueDecl>(member)) {
-      ConcreteDeclRef witness = proto->getDefaultWitness(value);
+      auto witness = proto->getDefaultWitness(value);
       if (!witness)
         continue;