Fix assert in type substitution cloner

We might have to replace opaque archetypes to satisfy equality of types

Author: aschwaighofer

include/swift/SIL/TypeSubstCloner.h

@@ -109,7 +109,11 @@ class TypeSubstCloner : public SILClonerWithScopes<ImplClass> {
 
       assert(Subs.empty() ||
              SubstCalleeSILType ==
-                 Callee->getType().substGenericArgs(AI.getModule(), Subs));
+                 Callee->getType().substGenericArgs(AI.getModule(), Subs) ||
+             (Cloner.ReplacingOpaqueArchetypes &&
+              SubstCalleeSILType ==
+                  Cloner.getOpType(Callee->getType().substGenericArgs(
+                      AI.getModule(), Subs))));
     }
 
     ArrayRef<SILValue> getArguments() const {
@@ -155,12 +159,14 @@ class TypeSubstCloner : public SILClonerWithScopes<ImplClass> {
   TypeSubstCloner(SILFunction &To,
                   SILFunction &From,
                   SubstitutionMap ApplySubs,
-                  bool Inlining = false)
+                  bool Inlining = false,
+                  bool ReplacingOpaqueArchetypes = false)
     : SILClonerWithScopes<ImplClass>(To, Inlining),
       SwiftMod(From.getModule().getSwiftModule()),
       SubsMap(ApplySubs),
       Original(From),
-      Inlining(Inlining) {
+      Inlining(Inlining),
+      ReplacingOpaqueArchetypes(ReplacingOpaqueArchetypes) {
   }
 
 protected:
@@ -381,6 +387,8 @@ class TypeSubstCloner : public SILClonerWithScopes<ImplClass> {
   SILFunction &Original;
   /// True, if used for inlining.
   bool Inlining;
+  /// True if replacing opaque result archetypes.
+  bool ReplacingOpaqueArchetypes;
 };
 
 } // end namespace swift

lib/SILOptimizer/Transforms/SpecializeOpaqueArchetypes.cpp

@@ -1,5 +1,6 @@
 #define DEBUG_TYPE "opaque-archetype-specializer"
 
+#include "swift/AST/Types.h"
 #include "swift/SIL/SILFunction.h"
 #include "swift/SIL/TypeSubstCloner.h"
 #include "swift/SIL/SILInstruction.h"
@@ -25,7 +26,8 @@ class OpaqueSpecializerCloner
   friend class SILInstructionVisitor<OpaqueSpecializerCloner>;
 
   OpaqueSpecializerCloner(SubstitutionMap opaqueArchetypeSubs, SILFunction &fun)
-      : SuperTy(fun, fun, opaqueArchetypeSubs) {
+      : SuperTy(fun, fun, opaqueArchetypeSubs, false /*Inlining*/,
+                true /*ReplacingOpaqueArchetypes*/) {
     entryBlock = fun.getEntryBlock();
     cloneFromBlock = entryBlock->split(entryBlock->begin());
   }
@@ -49,7 +51,8 @@ class OpaqueSpecializerCloner
     getBuilder().setCurrentDebugScope(getOpScope(Inst->getDebugScope()));
     auto origResult = Inst->getOperand();
     auto clonedResult = getOpValue(Inst->getOperand());
-    if (clonedResult->getType().getASTType() != origResult->getType().getASTType())
+    if (clonedResult->getType().getASTType() !=
+        origResult->getType().getASTType())
       clonedResult = getBuilder().createUncheckedRefCast(
           RegularLocation::getAutoGeneratedLocation(), clonedResult,
           origResult->getType());

test/SILOptimizer/specialize_opaque_type_archetypes.swift

@@ -206,3 +206,25 @@ public func usePair() {
   useP(x.first.myValue())
   useP(x.second.myValue())
 }
+
+public protocol P3 {
+  associatedtype AT
+  func foo() -> AT
+}
+
+public struct Adapter<T: P3>: P3 {
+  var inner: T
+  public func foo() -> some P3 {
+    return inner
+  }
+}
+
+// Don't assert.
+// CHECK-LABEL: sil {{.*}} @$s1A7AdapterVyxGAA2P3A2aEP3foo2ATQzyFTW
+// CHECK:  [[F:%.*]] = function_ref @$s1A7AdapterV3fooQryF
+// CHECK:  apply [[F]]<τ_0_0>(%0, %1) : $@convention(method) <τ_0_0 where τ_0_0 : P3> (@in_guaranteed Adapter<τ_0_0>) -> @out @_opaqueReturnTypeOf("$s1A7AdapterV3fooQryF", 0)
+extension P3 {
+  public func foo() -> some P3 {
+    return Adapter(inner: self)
+  }
+}