Sema: Remove some redundant conformance lookup callbacks

Now we have LookUpConformanceInModule and
LookUpConformanceInSubstitutionMap.

Author: slavapestov

lib/AST/GenericEnvironment.cpp

@@ -332,15 +332,10 @@ Type GenericEnvironment::getSugaredType(Type type) const {
 
 ArrayRef<Substitution>
 GenericEnvironment::getForwardingSubstitutions() const {
-  auto lookupConformanceFn =
-      [&](CanType original, Type replacement, ProtocolType *protoType)
-      -> Optional<ProtocolConformanceRef> {
-        return ProtocolConformanceRef(protoType->getDecl());
-      };
-
   SmallVector<Substitution, 4> result;
   getGenericSignature()->getSubstitutions(QueryInterfaceTypeSubstitutions(this),
-                                          lookupConformanceFn, result);
+                                          MakeAbstractConformanceForGenericType(),
+                                          result);
   return getGenericSignature()->getASTContext().AllocateCopy(result);
 }
 

lib/AST/GenericSignature.cpp

@@ -409,13 +409,9 @@ getSubstitutions(TypeSubstitutionFn subs,
 void GenericSignature::
 getSubstitutions(const SubstitutionMap &subMap,
                  SmallVectorImpl<Substitution> &result) const {
-  auto lookupConformanceFn =
-      [&](CanType original, Type replacement, ProtocolType *protoType)
-      -> Optional<ProtocolConformanceRef> {
-        return subMap.lookupConformance(original, protoType->getDecl());
-      };
-
-  getSubstitutions(subMap.getMap(), lookupConformanceFn, result);
+  getSubstitutions(subMap.getMap(),
+                   LookUpConformanceInSubstitutionMap(subMap),
+                   result);
 }
 
 bool GenericSignature::requiresClass(Type type, ModuleDecl &mod) {

lib/AST/Module.cpp

@@ -634,31 +634,9 @@ TypeBase::gatherAllSubstitutions(ModuleDecl *module,
     }
   }
 
-  auto lookupConformanceFn =
-      [&](CanType original, Type replacement, ProtocolType *protoType)
-      -> Optional<ProtocolConformanceRef> {
-        auto *proto = protoType->getDecl();
-
-        // If the type is a type variable or is dependent, just fill in empty
-        // conformances.
-        if (replacement->isTypeVariableOrMember() ||
-            replacement->isTypeParameter())
-          return ProtocolConformanceRef(proto);
-
-        // Otherwise, try to find the conformance.
-        auto conforms = module->lookupConformance(replacement, proto, resolver);
-        if (conforms)
-          return *conforms;
-
-        // FIXME: Should we ever end up here?
-        // We should return None and let getSubstitutions handle the error
-        // if we do.
-        return ProtocolConformanceRef(proto);
-      };
-
   SmallVector<Substitution, 4> result;
   genericSig->getSubstitutions(substitutions,
-                               lookupConformanceFn,
+                               LookUpConformanceInModule(module),
                                result);
 
   // Before recording substitutions, make sure we didn't end up doing it
@@ -762,9 +740,8 @@ ModuleDecl::lookupConformance(Type type, ProtocolDecl *protocol,
   }
 
   // Type variables have trivial conformances.
-  if (type->isTypeVariableOrMember()) {
+  if (type->isTypeVariableOrMember())
     return ProtocolConformanceRef(protocol);
-  }
 
   // UnresolvedType is a placeholder for an unknown type used when generating
   // diagnostics.  We consider it to conform to all protocols, since the

lib/AST/Type.cpp

@@ -2949,6 +2949,9 @@ Optional<ProtocolConformanceRef>
 LookUpConformanceInModule::operator()(CanType dependentType,
                                       Type conformingReplacementType,
                                       ProtocolType *conformedProtocol) const {
+  if (conformingReplacementType->isTypeParameter())
+    return ProtocolConformanceRef(conformedProtocol->getDecl());
+
   return M->lookupConformance(conformingReplacementType,
                   conformedProtocol->getDecl(),
                   conformingReplacementType->getASTContext().getLazyResolver());