Fix easy crashers

lib/AST/ASTDumper.cpp

@@ -642,8 +642,10 @@ namespace {
     void printAbstractTypeParamCommon(AbstractTypeParamDecl *decl,
                                       const char *name) {
       printCommon(decl, name);
-      if (auto superclassTy = decl->getSuperclass()) {
-        OS << " superclass='" << superclassTy->getString() << "'";
+      if (decl->getDeclContext()->getGenericEnvironmentOfContext()) {
+        if (auto superclassTy = decl->getSuperclass()) {
+          OS << " superclass='" << superclassTy->getString() << "'";
+        }
       }
     }
 

lib/AST/DeclContext.cpp

@@ -445,6 +445,12 @@ DeclContext *DeclContext::getParentForLookup() const {
     // outer types.
     return getModuleScopeContext();
   }
+  if (isa<NominalTypeDecl>(this)) {
+    // If we are inside a nominal type that is inside a protocol,
+    // skip the protocol.
+    if (isa<ProtocolDecl>(getParent()))
+      return getModuleScopeContext();
+  }
   return getParent();
 }
 

lib/AST/Type.cpp

@@ -3906,24 +3906,25 @@ case TypeKind::Id:
 
   case TypeKind::ProtocolComposition: {
     auto pc = cast<ProtocolCompositionType>(base);
-    SmallVector<Type, 4> members;
+    SmallVector<Type, 4> substMembers;
+    auto members = pc->getMembers();
     bool anyChanged = false;
     unsigned index = 0;
-    for (auto member : pc->getMembers()) {
+    for (auto member : members) {
       auto substMember = member.transformRec(fn);
       if (!substMember)
         return Type();
 
       if (anyChanged) {
-        members.push_back(substMember);
+        substMembers.push_back(substMember);
         ++index;
         continue;
       }
 
       if (substMember.getPointer() != member.getPointer()) {
         anyChanged = true;
-        members.append(members.begin(), members.begin() + index);
-        members.push_back(substMember);
+        substMembers.append(members.begin(), members.begin() + index);
+        substMembers.push_back(substMember);
       }
 
       ++index;
@@ -3932,7 +3933,8 @@ case TypeKind::Id:
     if (!anyChanged)
       return *this;
 
-    return ProtocolCompositionType::get(Ptr->getASTContext(), members,
+    return ProtocolCompositionType::get(Ptr->getASTContext(),
+                                        substMembers,
                                         pc->hasExplicitAnyObject());
   }
   }

lib/Sema/ITCDecl.cpp

@@ -342,8 +342,6 @@ void IterativeTypeChecker::processResolveTypeDecl(
   if (auto typeAliasDecl = dyn_cast<TypeAliasDecl>(typeDecl)) {
     if (typeAliasDecl->getDeclContext()->isModuleScopeContext() &&
         typeAliasDecl->getGenericParams() == nullptr) {
-      typeAliasDecl->setValidationStarted();
-
       TypeResolutionOptions options = TR_TypeAliasUnderlyingType;
       if (typeAliasDecl->getFormalAccess() <= Accessibility::FilePrivate)
         options |= TR_KnownNonCascadingDependency;

lib/Sema/TypeCheckNameLookup.cpp

@@ -414,6 +414,14 @@ LookupTypeResult TypeChecker::lookupMemberType(DeclContext *dc,
           continue;
         }
       }
+
+      // Nominal type members of protocols cannot be accessed with an
+      // archetype base, because we have no way to recover the correct
+      // substitutions.
+      if (type->is<ArchetypeType>() &&
+          isa<NominalTypeDecl>(typeDecl)) {
+        continue;
+      }
     }
 
     // Substitute the base into the member's type.
@@ -451,6 +459,13 @@ LookupTypeResult TypeChecker::lookupMemberType(DeclContext *dc,
       // Use the type witness.
       auto concrete = conformance->getConcrete();
       Type memberType = concrete->getTypeWitness(assocType, this);
+
+      // This is the only case where NormalProtocolConformance::
+      // getTypeWitnessAndDecl() returns a null type.
+      if (concrete->getState() ==
+          ProtocolConformanceState::CheckingTypeWitnesses)
+        continue;
+
       assert(memberType && "Missing type witness?");
 
       // If we haven't seen this type result yet, add it to the result set.

lib/Sema/TypeCheckProtocol.cpp

@@ -3286,15 +3286,21 @@ ResolveWitnessResult ConformanceChecker::resolveWitnessViaDefault(
 ///
 /// \returns an empty result on success, or a description of the error.
 static CheckTypeWitnessResult checkTypeWitness(TypeChecker &tc, DeclContext *dc,
+                                               ProtocolDecl *proto,
                                                AssociatedTypeDecl *assocType, 
                                                Type type) {
-  if (auto superclass = assocType->getSuperclass()) {
+  auto *moduleDecl = dc->getParentModule();
+  auto *reqtSig = assocType->getProtocol()->getRequirementSignature();
+  auto *depTy = DependentMemberType::get(proto->getSelfInterfaceType(),
+                                         assocType);
+
+  if (auto superclass = reqtSig->getSuperclassBound(depTy, *moduleDecl)) {
     if (!superclass->isExactSuperclassOf(type))
       return superclass->getAnyNominal();
   }
 
   // Check protocol conformances.
-  for (auto reqProto : assocType->getConformingProtocols()) {
+  for (auto reqProto : reqtSig->getConformsTo(depTy, *moduleDecl)) {
     if (!tc.conformsToProtocol(type, reqProto, dc, None))
       return reqProto;
 
@@ -3323,6 +3329,11 @@ static CheckTypeWitnessResult checkTypeWitness(TypeChecker &tc, DeclContext *dc,
 /// Attempt to resolve a type witness via member name lookup.
 ResolveWitnessResult ConformanceChecker::resolveTypeWitnessViaLookup(
                        AssociatedTypeDecl *assocType) {
+  if (!Proto->isRequirementSignatureComputed()) {
+    Conformance->setInvalid();
+    return ResolveWitnessResult::Missing;
+  }
+
   // Look for a member type with the same name as the associated type.
   auto candidates = TC.lookupMemberType(DC, Adoptee, assocType->getName(),
                                         NameLookupFlags::ProtocolMembers);
@@ -3342,7 +3353,7 @@ ResolveWitnessResult ConformanceChecker::resolveTypeWitnessViaLookup(
         continue;
 
     // Check this type against the protocol requirements.
-    if (auto checkResult = checkTypeWitness(TC, DC, assocType, 
+    if (auto checkResult = checkTypeWitness(TC, DC, Proto, assocType,
                                             candidate.second)) {
       auto reqProto = checkResult.getProtocolOrClass();
       nonViable.push_back({candidate.first, reqProto});
@@ -3603,7 +3614,7 @@ ConformanceChecker::inferTypeWitnessesViaValueWitnesses(
       if (!canInferFromOtherAssociatedType) {
         // Check that the type witness meets the
         // requirements on the associated type.
-        if (auto failed = checkTypeWitness(TC, DC, result.first,
+        if (auto failed = checkTypeWitness(TC, DC, Proto, result.first,
                                            result.second)) {
           witnessResult.NonViable.push_back(
                               std::make_tuple(result.first,result.second,failed));
@@ -4196,7 +4207,7 @@ void ConformanceChecker::resolveTypeWitnesses() {
     if (!defaultType)
       return Type();
 
-    if (auto failed = checkTypeWitness(TC, DC, assocType, defaultType)) {
+    if (auto failed = checkTypeWitness(TC, DC, Proto, assocType, defaultType)) {
       // Record the failure, if we haven't seen one already.
       if (!failedDefaultedAssocType) {
         failedDefaultedAssocType = assocType;
@@ -4231,7 +4242,7 @@ void ConformanceChecker::resolveTypeWitnesses() {
       return Type();
 
     // Make sure that the derived type is sane.
-    if (checkTypeWitness(TC, DC, assocType, derivedType)) {
+    if (checkTypeWitness(TC, DC, Proto, assocType, derivedType)) {
       diagnoseOrDefer(assocType, true,
         [derivedType](NormalProtocolConformance *conformance) {
           // FIXME: give more detail here?

test/decl/nested/protocol.swift

@@ -40,9 +40,11 @@ protocol Racoon {
   associatedtype Stripes
   class Claw<T> { // expected-error{{type 'Claw' cannot be nested in protocol 'Racoon'}}
     func mangle(_ s: Stripes) {}
+    // expected-error@-1 {{use of undeclared type 'Stripes'}}
   }
   struct Fang<T> { // expected-error{{type 'Fang' cannot be nested in protocol 'Racoon'}}
     func gnaw(_ s: Stripes) {}
+    // expected-error@-1 {{use of undeclared type 'Stripes'}}
   }
   enum Fur { // expected-error{{type 'Fur' cannot be nested in protocol 'Racoon'}}
     case Stripes

test/decl/typealias/protocol.swift

@@ -202,6 +202,8 @@ struct S7 : P7 {
 
   func inExpressionContext() {
     _ = Y.self
+    _ = T5.T1.self
+    _ = T5.T2.self
   }
 }
 

validation-test/compiler_crashers/28728-d-isbeingvalidated-d-hasvalidsignature.swift → validation-test/compiler_crashers_fixed/28728-d-isbeingvalidated-d-hasvalidsignature.swift

@@ -6,6 +6,6 @@
 // See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
 
 // REQUIRES: asserts
-// RUN: not --crash %target-swift-frontend %s -emit-ir
+// RUN: not %target-swift-frontend %s -emit-ir
 typealias e:a
 struct A:a{}typealias a=A

validation-test/compiler_crashers/28733-parent-parent-is-nominaltype-parent-is-boundgenerictype-parent-is-unboundgeneric.swift → validation-test/compiler_crashers_fixed/28733-parent-parent-is-nominaltype-parent-is-boundgenerictype-parent-is-unboundgeneric.swift

@@ -6,5 +6,5 @@
 // See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
 
 // REQUIRES: asserts
-// RUN: not --crash %target-swift-frontend %s -emit-ir
+// RUN: not %target-swift-frontend %s -emit-ir
 protocol P{class a:Self.a

validation-test/compiler_crashers/28748-genericenv-nullptr-too-much-circularity.swift → validation-test/compiler_crashers_fixed/28748-genericenv-nullptr-too-much-circularity.swift

@@ -6,5 +6,5 @@
 // See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
 
 // REQUIRES: asserts
-// RUN: not --crash %target-swift-frontend %s -emit-ir
+// RUN: not %target-swift-frontend %s -emit-ir
 protocol A:a{{}typealias e:a}{}class a:A{typealias e:b

validation-test/compiler_crashers/28751-membertype-missing-type-witness.swift → validation-test/compiler_crashers_fixed/28751-membertype-missing-type-witness.swift

@@ -6,5 +6,5 @@
 // See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
 
 // REQUIRES: asserts
-// RUN: not --crash %target-swift-frontend %s -emit-ir
+// RUN: not %target-swift-frontend %s -emit-ir
 {class a:P{{}typealias a:Self.a}protocol P{typealias a

validation-test/compiler_crashers/28753-conforms-equivclass-conformsto-end.swift → validation-test/compiler_crashers_fixed/28753-conforms-equivclass-conformsto-end.swift

@@ -6,5 +6,5 @@
 // See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
 
 // REQUIRES: asserts
-// RUN: not --crash %target-swift-frontend %s -emit-ir
+// RUN: not %target-swift-frontend %s -emit-ir
 protocol A:A{{}class a{let ca{a{

validation-test/compiler_crashers/28765-inprotocol-isrequirementsignaturecomputed-missing-signature.swift → validation-test/compiler_crashers_fixed/28765-inprotocol-isrequirementsignaturecomputed-missing-signature.swift

@@ -6,5 +6,5 @@
 // See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
 
 // REQUIRES: asserts
-// RUN: not --crash %target-swift-frontend %s -emit-ir
+// RUN: not %target-swift-frontend %s -emit-ir
 protocol P{{}class a:A{}protocol A:P.a{typealias a{}func a:a

validation-test/compiler_crashers/28768-isactuallycanonicalornull-forming-a-cantype-out-of-a-non-canonical-type.swift → validation-test/compiler_crashers_fixed/28768-isactuallycanonicalornull-forming-a-cantype-out-of-a-non-canonical-type.swift

@@ -6,6 +6,6 @@
 // See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
 
 // REQUIRES: asserts
-// RUN: not --crash %target-swift-frontend %s -emit-ir
+// RUN: not %target-swift-frontend %s -emit-ir
 Indexable
 & ManagedBuffer

validation-test/compiler_crashers/28773-unreachable-executed-at-swift-lib-sema-cssimplify-cpp-4808.swift → validation-test/compiler_crashers_fixed/28773-unreachable-executed-at-swift-lib-sema-cssimplify-cpp-4808.swift

@@ -5,5 +5,5 @@
 // See https://swift.org/LICENSE.txt for license information
 // See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
 
-// RUN: not --crash %target-swift-frontend %s -emit-ir
+// RUN: not %target-swift-frontend %s -emit-ir
 @objc protocol P{{}typealias a{}class a{let c=a{