IRGen: Fix specialized conformances with abstract conditional requirements in the partial apply forwarder

2nd attempt.

rdar://59723512

Author: aschwaighofer

lib/IRGen/GenProto.cpp

@@ -2743,8 +2743,7 @@ void NecessaryBindings::addTypeMetadata(CanType type) {
 static void addAbstractConditionalRequirements(
     SpecializedProtocolConformance *specializedConformance,
     llvm::SetVector<GenericRequirement> &requirements) {
-  auto module = specializedConformance->getDeclContext()->getParentModule();
-  auto subMap = specializedConformance->getSubstitutions(module);
+  auto subMap = specializedConformance->getSubstitutionMap();
   auto condRequirements =
       specializedConformance->getConditionalRequirementsIfAvailable();
   if (!condRequirements)
@@ -2756,11 +2755,23 @@ static void addAbstractConditionalRequirements(
     auto *proto =
         req.getSecondType()->castTo<ProtocolType>()->getDecl();
     auto ty = req.getFirstType()->getCanonicalType();
+    if (!isa<ArchetypeType>(ty))
+      continue;
     auto conformance = subMap.lookupConformance(ty, proto);
     if (!conformance.isAbstract())
       continue;
     requirements.insert({ty, conformance.getAbstract()});
   }
+  // Recursively add conditional requirements.
+  for (auto &conf : subMap.getConformances()) {
+    if (conf.isAbstract())
+      continue;
+    auto specializedConf =
+        dyn_cast<SpecializedProtocolConformance>(conf.getConcrete());
+    if (!specializedConf)
+      continue;
+    addAbstractConditionalRequirements(specializedConf, requirements);
+  }
 }
 
 void NecessaryBindings::addProtocolConformance(CanType type,

test/IRGen/partial_apply_forwarder.sil

@@ -269,7 +269,11 @@ extension Outer : MyEquatable where Value : MyEquatable {
   public static func isEqual (lhs: Outer<Value>, rhs: Outer<Value>) -> Builtin.Int1
 }
 
+public struct Outermost<Value> {
+}
+
 sil @$closure : $@convention(method) <Value where Value : MyEquatable> (Outer<Value>, Outer<Value>, @thin Outer<Value>.Type) -> Builtin.Int1
+sil @$closure2 : $@convention(method) <Value where Value : MyEquatable> (Outermost<Value>, Outermost<Value>, @thin Outermost<Value>.Type) -> Builtin.Int1
 
 sil @$dont_crash_test_caputre_specialized_conditional_conformance : $@convention(thin) <Element where Element : MyEquatable> (Outer<Inner<Element>>) -> () {
 bb0(%0 : $Outer<Inner<Element>>):
@@ -284,6 +288,17 @@ bb0(%0 : $Outer<Inner<Element>>):
   return %15 : $()
 }
 
+sil @$dont_crash_test_caputre_specialized_conditional_conformance_nested : $@convention(thin) <Element where Element : MyEquatable> (Outer<Inner<Element>>) -> () {
+bb0(%0 : $Outer<Inner<Element>>):
+  %4 = metatype $@thin Outermost<Outer<Inner<Element>>>.Type
+  %5 = function_ref @$closure2 : $@convention(method) <Value where Value : MyEquatable> (Outermost<Value>, Outermost<Value>, @thin Outermost<Value>.Type) -> Builtin.Int1
+  %6 = partial_apply [callee_guaranteed] %5<Outer<Inner<Element>>>(%4) : $@convention(method) <Value where Value : MyEquatable> (Outermost<Value>, Outermost<Value>, @thin Outermost<Value>.Type) -> Builtin.Int1
+  strong_release %6 : $@callee_guaranteed (Outermost<Outer<Inner<Element>>>, Outermost<Outer<Inner<Element>>>) -> Builtin.Int1
+  %15 = tuple ()
+  return %15 : $()
+}
+
+
 sil_vtable WeakBox {}
 sil_vtable C {}
 sil_vtable D {}