[Demangler] Add convenience functions to ask about types.

include/swift/Demangling/Demangle.h

@@ -246,6 +246,31 @@ bool isSwiftSymbol(const char *mangledName);
 /// This does not include the old (<= swift 3.x) mangling prefix "_T".
 llvm::StringRef dropSwiftManglingPrefix(llvm::StringRef mangledName);
 
+/// Returns true if the mangled name is an alias type name.
+///
+/// \param mangledName A null-terminated string containing a mangled name.
+bool isAlias(llvm::StringRef mangledName);
+
+/// Returns true if the mangled name is a class type name.
+///
+/// \param mangledName A null-terminated string containing a mangled name.
+bool isClass(llvm::StringRef mangledName);
+
+/// Returns true if the mangled name is an enum type name.
+///
+/// \param mangledName A null-terminated string containing a mangled name.
+bool isEnum(llvm::StringRef mangledName);
+
+/// Returns true if the mangled name is a protocol type name.
+///
+/// \param mangledName A null-terminated string containing a mangled name.
+bool isProtocol(llvm::StringRef mangledName);
+
+/// Returns true if the mangled name is a structure type name.
+///
+/// \param mangledName A null-terminated string containing a mangled name.
+bool isStruct(llvm::StringRef mangledName);
+
 /// Returns true if the mangled name has the old scheme of function type
 /// mangling where labels are part of the type.
 ///

lib/Demangling/Demangler.cpp

@@ -168,6 +168,94 @@ llvm::StringRef swift::Demangle::dropSwiftManglingPrefix(StringRef mangledName){
   return mangledName.drop_front(getManglingPrefixLength(mangledName));
 }
 
+static bool isAliasNode(Demangle::NodePointer Node) {
+  switch (Node->getKind()) {
+  case Demangle::Node::Kind::Type:
+    return isAliasNode(Node->getChild(0));
+  case Demangle::Node::Kind::TypeAlias:
+    return true;
+  default:
+    return false;
+  }
+  llvm_unreachable("Unhandled node kind!");
+}
+
+bool swift::Demangle::isAlias(llvm::StringRef mangledName) {
+  Demangle::Demangler Dem;
+  return isAliasNode(Dem.demangleType(mangledName));
+}
+
+static bool isClassNode(Demangle::NodePointer Node) {
+  switch (Node->getKind()) {
+  case Demangle::Node::Kind::Type:
+    return isClassNode(Node->getChild(0));
+  case Demangle::Node::Kind::Class:
+  case Demangle::Node::Kind::BoundGenericClass:
+    return true;
+  default:
+    return false;
+  }
+  llvm_unreachable("Unhandled node kind!");
+}
+
+bool swift::Demangle::isClass(llvm::StringRef mangledName) {
+  Demangle::Demangler Dem;
+  return isClassNode(Dem.demangleType(mangledName));
+}
+
+static bool isEnumNode(Demangle::NodePointer Node) {
+  switch (Node->getKind()) {
+  case Demangle::Node::Kind::Type:
+    return isEnumNode(Node->getChild(0));
+  case Demangle::Node::Kind::Enum:
+  case Demangle::Node::Kind::BoundGenericEnum:
+    return true;
+  default:
+    return false;
+  }
+  llvm_unreachable("Unhandled node kind!");
+}
+
+bool swift::Demangle::isEnum(llvm::StringRef mangledName) {
+  Demangle::Demangler Dem;
+  return isEnumNode(Dem.demangleType(mangledName));
+}
+
+static bool isProtocolNode(Demangle::NodePointer Node) {
+  switch (Node->getKind()) {
+  case Demangle::Node::Kind::Type:
+    return isProtocolNode(Node->getChild(0));
+  case Demangle::Node::Kind::Protocol:
+    return true;
+  default:
+    return false;
+  }
+  llvm_unreachable("Unhandled node kind!");
+}
+
+bool swift::Demangle::isProtocol(llvm::StringRef mangledName) {
+  Demangle::Demangler Dem;
+  return isProtocolNode(Dem.demangleType(dropSwiftManglingPrefix(mangledName)));
+}
+
+static bool isStructNode(Demangle::NodePointer Node) {
+  switch (Node->getKind()) {
+  case Demangle::Node::Kind::Type:
+    return isStructNode(Node->getChild(0));
+  case Demangle::Node::Kind::Structure:
+  case Demangle::Node::Kind::BoundGenericStructure:
+    return true;
+  default:
+    return false;
+  }
+  llvm_unreachable("Unhandled node kind!");
+}
+
+bool swift::Demangle::isStruct(llvm::StringRef mangledName) {
+  Demangle::Demangler Dem;
+  return isStructNode(Dem.demangleType(mangledName));
+}
+
 namespace swift {
 namespace Demangle {
 

stdlib/public/Reflection/TypeRef.cpp

@@ -420,92 +420,22 @@ GenericArgumentMap TypeRef::getSubstMap() const {
   return Substitutions;
 }
 
-namespace {
-bool isStruct(Demangle::NodePointer Node) {
-  switch (Node->getKind()) {
-    case Demangle::Node::Kind::Type:
-      return isStruct(Node->getChild(0));
-    case Demangle::Node::Kind::Structure:
-    case Demangle::Node::Kind::BoundGenericStructure:
-      return true;
-    default:
-      return false;
-  }
-}
-bool isEnum(Demangle::NodePointer Node) {
-  switch (Node->getKind()) {
-    case Demangle::Node::Kind::Type:
-      return isEnum(Node->getChild(0));
-    case Demangle::Node::Kind::Enum:
-    case Demangle::Node::Kind::BoundGenericEnum:
-      return true;
-    default:
-      return false;
-  }
-}
-bool isClass(Demangle::NodePointer Node) {
-  switch (Node->getKind()) {
-    case Demangle::Node::Kind::Type:
-      return isClass(Node->getChild(0));
-    case Demangle::Node::Kind::Class:
-    case Demangle::Node::Kind::BoundGenericClass:
-      return true;
-    default:
-      return false;
-  }
-}
-bool isProtocol(Demangle::NodePointer Node) {
-  switch (Node->getKind()) {
-    case Demangle::Node::Kind::Type:
-      return isProtocol(Node->getChild(0));
-    case Demangle::Node::Kind::Protocol:
-      return true;
-    default:
-      return false;
-  }
-}
-
-bool isAlias(Demangle::NodePointer Node) {
-  switch (Node->getKind()) {
-    case Demangle::Node::Kind::Type:
-      return isAlias(Node->getChild(0));
-    case Demangle::Node::Kind::TypeAlias:
-      return true;
-    default:
-      return false;
-  }
-}
-} // end anonymous namespace
-
 bool NominalTypeTrait::isStruct() const {
-  Demangle::Demangler Dem;
-  Demangle::NodePointer Demangled = Dem.demangleType(MangledName);
-  return ::isStruct(Demangled);
+  return Demangle::isStruct(MangledName);
 }
 
-bool NominalTypeTrait::isEnum() const {
-  Demangle::Demangler Dem;
-  Demangle::NodePointer Demangled = Dem.demangleType(MangledName);
-  return ::isEnum(Demangled);
-}
+bool NominalTypeTrait::isEnum() const { return Demangle::isEnum(MangledName); }
 
 bool NominalTypeTrait::isClass() const {
-  Demangle::Demangler Dem;
-  Demangle::NodePointer Demangled = Dem.demangleType(MangledName);
-  return ::isClass(Demangled);
+  return Demangle::isClass(MangledName);
 }
 
 bool NominalTypeTrait::isProtocol() const {
-  Demangle::Demangler Dem;
-  StringRef adjustedMangledName = Demangle::dropSwiftManglingPrefix(MangledName);
-  Demangle::NodePointer Demangled = Dem.demangleType(adjustedMangledName);
-  return ::isProtocol(Demangled);
+  return Demangle::isProtocol(MangledName);
 }
 
 bool NominalTypeTrait::isAlias() const {
-  Demangle::Demangler Dem;
-  Demangle::NodePointer Demangled = Dem.demangleType(MangledName);
-  return ::isAlias(Demangled);
+  return Demangle::isAlias(MangledName);
 }
 
 /// Visitor class to set the WasAbstract flag of any MetatypeTypeRefs