Fixes for assorted SILGen bugs

lib/SIL/SILFunctionType.cpp

@@ -2209,6 +2209,28 @@ namespace {
                                            substObjectType));
     }
 
+    /// Metatypes get DynamicSelfType stripped off the instance type.
+    CanType visitMetatypeType(CanMetatypeType origType) {
+      CanType origInstanceType = origType.getInstanceType();
+      CanType substInstanceType = origInstanceType.subst(
+            Subst, Conformances, None)->getCanonicalType();
+
+      // If the substitution didn't change anything, we know that the
+      // original type was a lowered type, so we're good.
+      if (origInstanceType == substInstanceType) {
+        return origType;
+      }
+
+      // If this is a DynamicSelf metatype, turn it into a metatype of the
+      // underlying self type.
+      if (auto dynamicSelf = dyn_cast<DynamicSelfType>(substInstanceType)) {
+        substInstanceType = dynamicSelf.getSelfType();
+      }
+
+      return CanMetatypeType::get(substInstanceType,
+                                  origType->getRepresentation());
+    }
+
     /// Any other type is would be a valid type in the AST.  Just
     /// apply the substitution on the AST level and then lower that.
     CanType visitType(CanType origType) {

lib/SIL/TypeLowering.cpp

@@ -1235,30 +1235,6 @@ void TypeConverter::insert(TypeKey k, const TypeLowering *tl) {
   Types[k.getCachingKey()] = tl;
 }
 
-#ifndef NDEBUG
-/// Is this type a lowered type?
-static bool isLoweredType(CanType type) {
-  if (isa<LValueType>(type) || isa<InOutType>(type))
-    return false;
-  if (isa<AnyFunctionType>(type))
-    return false;
-  if (auto tuple = dyn_cast<TupleType>(type)) {
-    for (auto elt : tuple.getElementTypes())
-      if (!isLoweredType(elt))
-        return false;
-    return true;
-  }
-  OptionalTypeKind optKind;
-  if (auto objectType = type.getAnyOptionalObjectType(optKind)) {
-    return (optKind == OTK_Optional && isLoweredType(objectType));
-  }
-  if (auto meta = dyn_cast<AnyMetatypeType>(type)) {
-    return meta->hasRepresentation();
-  }
-  return true;
-}
-#endif
-
 /// Lower each of the elements of the substituted type according to
 /// the abstraction pattern of the given original type.
 static CanTupleType getLoweredTupleType(TypeConverter &tc,
@@ -1525,7 +1501,7 @@ const TypeLowering &TypeConverter::getTypeLowering(SILType type) {
 const TypeLowering &
 TypeConverter::getTypeLoweringForLoweredType(TypeKey key) {
   auto type = key.SubstType;
-  assert(isLoweredType(type) && "type is not lowered!");
+  assert(type->isLegalSILType() && "type is not lowered!");
   (void)type;
 
   // Re-using uncurry level 0 is reasonable because our uncurrying
@@ -1542,7 +1518,7 @@ TypeConverter::getTypeLoweringForLoweredType(TypeKey key) {
 const TypeLowering &
 TypeConverter::getTypeLoweringForUncachedLoweredType(TypeKey key) {
   assert(!find(key) && "re-entrant or already cached");
-  assert(isLoweredType(key.SubstType) && "type is not already lowered");
+  assert(key.SubstType->isLegalSILType() && "type is not already lowered");
 
 #ifndef NDEBUG
   // Catch reentrancy bugs.

lib/SILGen/ArgumentSource.cpp

@@ -55,7 +55,35 @@ bool ArgumentSource::requiresCalleeToEvaluate() {
   case Kind::LValue:
     return false;
   case Kind::Expr:
-    return isa<TupleShuffleExpr>(asKnownExpr());
+    // FIXME: TupleShuffleExprs come in two flavors:
+    //
+    // 1) as apply arguments, where they're used to insert default
+    // argument value and collect varargs
+    //
+    // 2) as tuple conversions, where they can introduce, eliminate
+    // and re-order fields
+    //
+    // Case 1) must be emitted by ArgEmitter, and Case 2) must be
+    // emitted by RValueEmitter.
+    //
+    // It would be good to split up TupleShuffleExpr into these two
+    // cases, and simplify ArgEmitter since it no longer has to deal
+    // with re-ordering. However for now, SubscriptExpr emits the
+    // index argument via the RValueEmitter, so the RValueEmitter has
+    // to know about varargs, duplicating some of the logic in
+    // ArgEmitter.
+    //
+    // Once this is fixed, we can also consider allowing subscripts
+    // to have default arguments.
+    if (auto *shuffleExpr = dyn_cast<TupleShuffleExpr>(asKnownExpr())) {
+      for (auto index : shuffleExpr->getElementMapping()) {
+        if (index == TupleShuffleExpr::DefaultInitialize ||
+            index == TupleShuffleExpr::CallerDefaultInitialize ||
+            index == TupleShuffleExpr::Variadic)
+          return true;
+      }
+    }
+    return false;
   }
 
   llvm_unreachable("Unhandled Kind in switch.");

lib/SILGen/SILGen.cpp

@@ -1408,6 +1408,9 @@ void SILGenModule::emitSourceFile(SourceFile *sf, unsigned startElem) {
   for (Decl *D : llvm::makeArrayRef(sf->Decls).slice(startElem))
     visit(D);
 
+  for (Decl *D : sf->LocalTypeDecls)
+    visit(D);
+
   // Mark any conformances as "used".
   for (auto conformance : sf->getUsedConformances())
     useConformance(ProtocolConformanceRef(conformance));

lib/SILGen/SILGenApply.cpp

@@ -558,14 +558,14 @@ class Callee {
       assert(level <= Constant.uncurryLevel
              && "uncurrying past natural uncurry level of method");
 
-      auto constant = Constant.atUncurryLevel(level);
+      constant = Constant.atUncurryLevel(level);
       // Lower the substituted type from the AST, which should have any generic
       // parameters in the original signature erased to their upper bounds.
       auto objcFormalType = SubstFormalType.withExtInfo(
          SubstFormalType->getExtInfo()
            .withSILRepresentation(SILFunctionTypeRepresentation::ObjCMethod));
       auto fnType = gen.SGM.M.Types
-        .getUncachedSILFunctionTypeForConstant(constant, objcFormalType);
+        .getUncachedSILFunctionTypeForConstant(*constant, objcFormalType);
 
       auto closureType =
         replaceSelfTypeForDynamicLookup(gen.getASTContext(), fnType,
@@ -574,9 +574,9 @@ class Callee {
 
       SILValue fn = gen.B.createDynamicMethod(Loc,
                           SelfValue,
-                          constant,
+                          *constant,
                           SILType::getPrimitiveObjectType(closureType),
-                          /*volatile*/ constant.isForeign);
+                          /*volatile*/ Constant.isForeign);
       mv = ManagedValue::forUnmanaged(fn);
       break;
     }
@@ -4694,15 +4694,16 @@ static RValue emitApplyAllocatingInitializer(SILGenFunction &SGF,
   {
     // Determine the self metatype type.
     CanSILFunctionType substFnType =
-      SGF.getLoweredType(substFormalType, /*uncurryLevel=*/1)
-      .castTo<SILFunctionType>();
+      initConstant.SILFnType->substGenericArgs(SGF.SGM.M, subs);
     SILType selfParamMetaTy = substFnType->getSelfParameter().getSILType();
 
     if (overriddenSelfType) {
       // If the 'self' type has been overridden, form a metatype to the
       // overriding 'Self' type.
       Type overriddenSelfMetaType =
-        MetatypeType::get(overriddenSelfType, SGF.getASTContext());
+        MetatypeType::get(overriddenSelfType,
+                          selfParamMetaTy.castTo<MetatypeType>()
+                              ->getRepresentation());
       selfMetaTy =
         SGF.getLoweredType(overriddenSelfMetaType->getCanonicalType());
     } else {

lib/SILGen/SILGenDynamicCast.cpp

@@ -357,20 +357,18 @@ adjustForConditionalCheckedCastOperand(SILLocation loc, ManagedValue src,
   }
 
   std::unique_ptr<TemporaryInitialization> init;
-  SGFContext ctx;
   if (requiresAddress) {
     init = SGF.emitTemporary(loc, srcAbstractTL);
-
+
+    if (hasAbstraction)
+      src = SGF.emitSubstToOrigValue(loc, src, abstraction, sourceType);
+
     // Okay, if all we need to do is drop the value in an address,
     // this is easy.
-    if (!hasAbstraction) {
-      SGF.B.emitStoreValueOperation(loc, src.forward(SGF), init->getAddress(),
-                                    StoreOwnershipQualifier::Init);
-      init->finishInitialization(SGF);
-      return init->getManagedAddress();
-    }
-
-    ctx = SGFContext(init.get());
+    SGF.B.emitStoreValueOperation(loc, src.forward(SGF), init->getAddress(),
+                                  StoreOwnershipQualifier::Init);
+    init->finishInitialization(SGF);
+    return init->getManagedAddress();
   }
 
   assert(hasAbstraction);

lib/SILGen/SILGenFunction.h

@@ -1545,7 +1545,6 @@ class LLVM_LIBRARY_VISIBILITY SILGenFunction
     llvm_unreachable("Not yet implemented");
   }
 
-  void visitNominalTypeDecl(NominalTypeDecl *D);
   void visitFuncDecl(FuncDecl *D);
   void visitPatternBindingDecl(PatternBindingDecl *D);
 
@@ -1554,6 +1553,10 @@ class LLVM_LIBRARY_VISIBILITY SILGenFunction
   std::unique_ptr<Initialization>
   emitPatternBindingInitialization(Pattern *P, JumpDest failureDest);
 
+  void visitNominalTypeDecl(NominalTypeDecl *D) {
+    // No lowering support needed.
+  }
+
   void visitTypeAliasDecl(TypeAliasDecl *D) {
     // No lowering support needed.
   }

lib/SILGen/SILGenLValue.cpp

@@ -831,10 +831,11 @@ namespace {
         return true;
       }
 
-      // If the declaration is dynamically dispatched through a protocol,
-      // we have to use materializeForSet.
-      if (isa<ProtocolDecl>(decl->getDeclContext()))
-        return true;
+      // If the declaration is dynamically dispatched through a
+      // non-ObjC protocol, we have to use materializeForSet.
+      if (auto *protoDecl = dyn_cast<ProtocolDecl>(decl->getDeclContext()))
+        if (!protoDecl->isObjC())
+          return true;
 
       return false;
     }