Sema: Don't call checkConformance() on a type that may contain type variables

Author: slavapestov

lib/Sema/CSSolver.cpp

@@ -2168,17 +2168,24 @@ void DisjunctionChoiceProducer::partitionGenericOperators(
   SmallVector<unsigned, 4> simdOverloads;
   SmallVector<unsigned, 4> otherGenericOverloads;
 
-  auto refinesOrConformsTo = [&](NominalTypeDecl *nominal, KnownProtocolKind kind) -> bool {
-    if (!nominal)
-      return false;
+  auto &ctx = CS.getASTContext();
+
+  auto *additiveArithmeticProto = ctx.getProtocol(KnownProtocolKind::AdditiveArithmetic);
+  auto *sequenceProto = ctx.getProtocol(KnownProtocolKind::Sequence);
+  auto *simdProto = ctx.getProtocol(KnownProtocolKind::SIMD);
 
-    auto *protocol =
-        TypeChecker::getProtocol(CS.getASTContext(), SourceLoc(), kind);
+  auto conformsTo = [&](Type type, ProtocolDecl *protocol) -> bool {
+    return protocol && bool(CS.lookupConformance(type, protocol));
+  };
+
+  auto refinesOrConformsTo = [&](NominalTypeDecl *nominal, ProtocolDecl *protocol) -> bool {
+    if (!nominal || !protocol)
+      return false;
 
     if (auto *refined = dyn_cast<ProtocolDecl>(nominal))
       return refined->inheritsFrom(protocol);
 
-    return bool(CS.lookupConformance(nominal->getDeclaredType(), protocol));
+    return conformsTo(nominal->getDeclaredInterfaceType(), protocol);
   };
 
   // Gather Numeric and Sequence overloads into separate buckets.
@@ -2191,9 +2198,9 @@ void DisjunctionChoiceProducer::partitionGenericOperators(
       simdOverloads.push_back(index);
     } else if (!decl->getInterfaceType()->is<GenericFunctionType>()) {
       concreteOverloads.push_back(index);
-    } else if (refinesOrConformsTo(nominal, KnownProtocolKind::AdditiveArithmetic)) {
+    } else if (refinesOrConformsTo(nominal, additiveArithmeticProto)) {
       numericOverloads.push_back(index);
-    } else if (refinesOrConformsTo(nominal, KnownProtocolKind::Sequence)) {
+    } else if (refinesOrConformsTo(nominal, sequenceProto)) {
       sequenceOverloads.push_back(index);
     } else {
       otherGenericOverloads.push_back(index);
@@ -2229,27 +2236,21 @@ void DisjunctionChoiceProducer::partitionGenericOperators(
     if (argType->isTypeVariableOrMember())
       continue;
 
-    if (TypeChecker::conformsToKnownProtocol(
-            argType, KnownProtocolKind::AdditiveArithmetic,
-            CS.DC->getParentModule())) {
+    if (conformsTo(argType, additiveArithmeticProto)) {
       first =
           std::copy(numericOverloads.begin(), numericOverloads.end(), first);
       numericOverloads.clear();
       break;
     }
 
-    if (TypeChecker::conformsToKnownProtocol(
-            argType, KnownProtocolKind::Sequence,
-            CS.DC->getParentModule())) {
+    if (conformsTo(argType, sequenceProto)) {
       first =
           std::copy(sequenceOverloads.begin(), sequenceOverloads.end(), first);
       sequenceOverloads.clear();
       break;
     }
 
-    if (TypeChecker::conformsToKnownProtocol(
-            argType, KnownProtocolKind::SIMD,
-            CS.DC->getParentModule())) {
+    if (conformsTo(argType, simdProto)) {
       first = std::copy(simdOverloads.begin(), simdOverloads.end(), first);
       simdOverloads.clear();
       break;