Merge pull request swiftlang#16693 from dcci/typerecogenerictypealiases

[TypeReconstruction] Add support for generic typealiases.

Author: dcci

lib/IDE/TypeReconstruction.cpp

@@ -755,6 +755,51 @@ static void VisitNodeAssociatedTypeRef(
       ident->getText().str().c_str());
 }
 
+static void VisitNodeGenericTypealias(ASTContext *ast,
+                                      Demangle::NodePointer cur_node,
+                                      VisitNodeResult &result) {
+  VisitNodeResult generic_type_result;
+  VisitNodeResult template_types_result;
+
+  Demangle::Node::iterator end = cur_node->end();
+  for (Demangle::Node::iterator pos = cur_node->begin(); pos != end; ++pos) {
+    const Demangle::Node::Kind child_node_kind = (*pos)->getKind();
+    switch (child_node_kind) {
+    case Demangle::Node::Kind::Type:
+      VisitNode(ast, *pos, generic_type_result);
+      break;
+    case Demangle::Node::Kind::TypeList:
+      VisitNode(ast, *pos, template_types_result);
+      break;
+    default:
+      break;
+    }
+  }
+
+  if (generic_type_result._decls.size() != 1 ||
+      generic_type_result._types.size() != 1 ||
+      template_types_result._types.empty())
+    return;
+
+  auto *genericTypeAlias =
+      cast<TypeAliasDecl>(generic_type_result._decls.front());
+  GenericSignature *signature = genericTypeAlias->getGenericSignature();
+  // FIXME: handle conformances.
+  SubstitutionMap subMap =
+      SubstitutionMap::get(signature, template_types_result._types,
+                           ArrayRef<ProtocolConformanceRef>({}));
+  Type parentType;
+  if (auto nominal = genericTypeAlias->getDeclContext()
+                         ->getAsNominalTypeOrNominalTypeExtensionContext()) {
+    parentType = nominal->getDeclaredInterfaceType();
+  }
+  NameAliasType *NAT =
+      NameAliasType::get(genericTypeAlias, parentType, subMap,
+                         genericTypeAlias->getUnderlyingTypeLoc().getType());
+  result._types.push_back(NAT);
+  result._decls.push_back(genericTypeAlias);
+}
+
 static void VisitNodeBoundGeneric(
     ASTContext *ast,
     Demangle::NodePointer cur_node, VisitNodeResult &result) {
@@ -2203,6 +2248,10 @@ static void VisitNode(
     VisitNodeBoundGeneric(ast, node, result);
     break;
 
+  case Demangle::Node::Kind::BoundGenericTypeAlias:
+    VisitNodeGenericTypealias(ast, node, result);
+    break;
+
   case Demangle::Node::Kind::BuiltinTypeName:
     VisitNodeBuiltinTypeName(ast, node, result);
     break;

test/DebugInfo/DumpDeclFromMangledName.swift

@@ -39,3 +39,19 @@ func patatino() -> Int {
 }
 
 patatino()
+
+class Foo<T> {
+  var x : T
+  init(_ x : T) {
+    self.x = x
+  }
+}
+
+typealias Patatino<T> = Foo<T>
+
+func main() -> Int {
+  var p : Patatino<Int> = Patatino(23);
+  return 0
+}
+
+let _ = main()

test/DebugInfo/DumpTypeFromMangledName.swift

@@ -12,14 +12,27 @@
 // RUN: diff %t.check %t.output
 
 // REQUIRES: executable_test
-func main() {
-  struct Patatino {}
-}
-
 extension Collection where Element: Equatable {
   func split<C: Collection>(separatedBy separator: C) -> [SubSequence]
     where C.Element == Element {
       var results = [SubSequence]()
       return results
   }
 }
+
+class Foo<T> {
+  var x : T
+  init(_ x : T) {
+    self.x = x
+  }
+}
+
+typealias Patatino<T> = Foo<T>
+
+func main() -> Int {
+  struct patatino {}
+  var p : Patatino<Int> = Patatino(23);
+  return 0
+}
+
+let _ = main()

test/DebugInfo/Inputs/decl-reconstr-names.txt

@@ -1,2 +1,3 @@
 $S12DeclReconstr8patatinoSiyF ---> func patatino() -> Int
 $S12DeclReconstr1SVACycfC ---> init()
+$S12DeclReconstr8PatatinoaySiGD ---> typealias Patatino<T> = Foo<T>

test/DebugInfo/Inputs/type-reconstr-names.txt

@@ -4,3 +4,4 @@ $Ss5Int32VD ---> Int32
 $S4blah4mainyyF8PatatinoL_VMa ---> Can't resolve type of $S4blah4mainyyF8PatatinoL_VMa
 $Ss10CollectionP7Element ---> Can't resolve type of $Ss10CollectionP7Element
 $Ss15ContiguousArrayV9formIndex5afterySiz_tFSS_Tg5 ---> (inout Int) -> ()
+$S12TypeReconstr8PatatinoaySiGD ---> Patatino<Int>