Merge remote-tracking branch 'origin/master' into master-next

Author: swift-ci

lib/Sema/CSSimplify.cpp

@@ -1965,12 +1965,7 @@ static ConstraintFix *fixRequirementFailure(ConstraintSystem &cs, Type type1,
                                             Type type2, Expr *anchor,
                                             ArrayRef<LocatorPathElt> path) {
   // Can't fix not yet properly resolved types.
-  if (type1->hasTypeVariable() || type2->hasTypeVariable())
-    return nullptr;
-
-  // If dependent members are present here it's because
-  // base doesn't conform to associated type's protocol.
-  if (type1->hasDependentMember() || type2->hasDependentMember())
+  if (type1->isTypeVariableOrMember() || type2->isTypeVariableOrMember())
     return nullptr;
 
   auto req = path.back();
@@ -1999,9 +1994,9 @@ static ConstraintFix *fixRequirementFailure(ConstraintSystem &cs, Type type1,
     return SkipSuperclassRequirement::create(cs, type1, type2, reqLoc);
   }
 
-  case RequirementKind::Conformance:
   case RequirementKind::Layout:
-    llvm_unreachable("conformance requirements are handled elsewhere");
+  case RequirementKind::Conformance:
+    return MissingConformance::forRequirement(cs, type1, type2, reqLoc);
   }
 }
 
@@ -2157,6 +2152,11 @@ bool ConstraintSystem::repairFailures(
 
   case ConstraintLocator::TypeParameterRequirement:
   case ConstraintLocator::ConditionalRequirement: {
+    // If dependent members are present here it's because
+    // base doesn't conform to associated type's protocol.
+    if (lhs->hasDependentMember() || rhs->hasDependentMember())
+      break;
+
     if (auto *fix = fixRequirementFailure(*this, lhs, rhs, anchor, path))
       conversionsOrFixes.push_back(fix);
     break;
@@ -3380,23 +3380,11 @@ ConstraintSystem::SolutionKind ConstraintSystem::simplifyConformsToConstraint(
 
     if (path.back().isTypeParameterRequirement() ||
         path.back().isConditionalRequirement()) {
-      if (path.back().isConditionalRequirement()) {
-        // Drop 'conditional requirement' element, remainder
-        // of the path is going to point to type requirement
-        // this conditional comes from.
-        auto reqPath = ArrayRef<LocatorPathElt>(path).drop_back();
-        // Underlying conformance requirement is itself fixed,
-        // this wouldn't lead to a right solution.
-        if (hasFixFor(getConstraintLocator(anchor, reqPath,
-                                           /*summaryFlags=*/0)))
-          return SolutionKind::Error;
+      if (auto *fix = fixRequirementFailure(
+              *this, type, protocol->getDeclaredType(), anchor, path)) {
+        if (!recordFix(fix))
+          return SolutionKind::Solved;
       }
-
-      auto *fix = MissingConformance::forRequirement(
-          *this, type, protocol->getDeclaredType(),
-          getConstraintLocator(locator));
-      if (!recordFix(fix))
-        return SolutionKind::Solved;
     }
 
     // If this is an implicit Hashable conformance check generated for each
@@ -6545,8 +6533,10 @@ bool ConstraintSystem::recordFix(ConstraintFix *fix) {
     // Always useful, unless duplicate of exactly the same fix and location.
     // This situation might happen when the same fix kind is applicable to
     // different overload choices.
-    if (!hasFixFor(fix->getLocator()))
-      Fixes.push_back(fix);
+    if (hasFixFor(fix->getLocator()))
+      return false;
+
+    Fixes.push_back(fix);
   } else {
     // Only useful to record if no pre-existing fix in the subexpr tree.
     llvm::SmallDenseSet<Expr *> fixExprs;