Merge pull request #11248 from apple/update-master-for-xcode-9-beta-4
Update master to build with Xcode 9 beta 4
diff --git a/lib/Sema/CSRanking.cpp b/lib/Sema/CSRanking.cpp
index 5ee2585..71f9f57 100644
--- a/lib/Sema/CSRanking.cpp
+++ b/lib/Sema/CSRanking.cpp
@@ -155,57 +155,6 @@
llvm_unreachable("Unhandled OverloadChoiceKind in switch.");
}
-/// Compare two declarations to determine whether one is a witness of the other.
-static Comparison compareWitnessAndRequirement(TypeChecker &tc, DeclContext *dc,
- ValueDecl *decl1,
- ValueDecl *decl2) {
- // We only have a witness/requirement pair if exactly one of the declarations
- // comes from a protocol.
- auto proto1 = dyn_cast<ProtocolDecl>(decl1->getDeclContext());
- auto proto2 = dyn_cast<ProtocolDecl>(decl2->getDeclContext());
- if ((bool)proto1 == (bool)proto2)
- return Comparison::Unordered;
-
- // Figure out the protocol, requirement, and potential witness.
- ProtocolDecl *proto;
- ValueDecl *req;
- ValueDecl *potentialWitness;
- if (proto1) {
- proto = proto1;
- req = decl1;
- potentialWitness = decl2;
- } else {
- proto = proto2;
- req = decl2;
- potentialWitness = decl1;
- }
-
- // Cannot compare type declarations this way.
- // FIXME: Use the same type-substitution approach as lookupMemberType.
- if (isa<TypeDecl>(req))
- return Comparison::Unordered;
-
- if (!potentialWitness->getDeclContext()->isTypeContext())
- return Comparison::Unordered;
-
- // Determine whether the type of the witness's context conforms to the
- // protocol.
- auto owningType
- = potentialWitness->getDeclContext()->getDeclaredInterfaceType();
- auto conformance = tc.conformsToProtocol(owningType, proto, dc,
- ConformanceCheckFlags::InExpression);
- if (!conformance || conformance->isAbstract())
- return Comparison::Unordered;
-
- // If the witness and the potential witness are not the same, there's no
- // ordering here.
- if (conformance->getConcrete()->getWitnessDecl(req, &tc) != potentialWitness)
- return Comparison::Unordered;
-
- // We have a requirement/witness match.
- return proto1? Comparison::Worse : Comparison::Better;
-}
-
namespace {
/// Describes the relationship between the context types for two declarations.
enum class SelfTypeRelationship {
@@ -504,18 +453,6 @@
return subscript2->isGeneric();
}
- // A witness is always more specialized than the requirement it satisfies.
- switch (compareWitnessAndRequirement(tc, dc, decl1, decl2)) {
- case Comparison::Unordered:
- break;
-
- case Comparison::Better:
- return true;
-
- case Comparison::Worse:
- return false;
- }
-
// Members of protocol extensions have special overloading rules.
ProtocolDecl *inProtocolExtension1 = outerDC1
->getAsProtocolExtensionContext();
