ScheduleTreeSequence: hide copy constructor

ScheduleTree nodes are not supposed to be manipulated by-value, only via
unique pointers.  Make the copy constructor of ScheduleTreeSequence
private, similarly to its main constructor, and provide a static member
function to return copies wrapped in a unique pointer.  Note that unlike
the conventional copy constructor, this static function takes a pointer
to the tree rather than a reference.  This keeps the API consistent as
all other functions manipulate with pointers to the tree nodes rather
than references.

Author: ftynse

tc/core/polyhedral/schedule_tree.cc

@@ -143,7 +143,7 @@ static std::unique_ptr<ScheduleTree> makeElem(const ScheduleTree& st) {
   ELEM_MAKE_CASE_CSTR(ScheduleTreeExtension)
   ELEM_MAKE_CASE_CSTR(ScheduleTreeFilter)
   ELEM_MAKE_CASE_CSTR(ScheduleTreeMapping)
-  ELEM_MAKE_CASE(ScheduleTreeSequence)
+  ELEM_MAKE_CASE_CSTR(ScheduleTreeSequence)
   ELEM_MAKE_CASE(ScheduleTreeSet)
   ELEM_MAKE_CASE(ScheduleTreeThreadSpecificMarker)
 

tc/core/polyhedral/schedule_tree_elem.cc

@@ -158,6 +158,15 @@ std::unique_ptr<ScheduleTreeSequence> ScheduleTreeSequence::make(
   return res;
 }
 
+std::unique_ptr<ScheduleTreeSequence> ScheduleTreeSequence::make(
+    const ScheduleTreeSequence* tree,
+    std::vector<ScheduleTreeUPtr>&& children) {
+  auto res =
+      std::unique_ptr<ScheduleTreeSequence>(new ScheduleTreeSequence(*tree));
+  res->appendChildren(std::move(children));
+  return res;
+}
+
 std::unique_ptr<ScheduleTreeSet> ScheduleTreeSet::make(
     isl::ctx ctx,
     std::vector<ScheduleTreeUPtr>&& children) {

tc/core/polyhedral/schedule_tree_elem.h

@@ -211,9 +211,9 @@ struct ScheduleTreeSequence : public ScheduleTree {
  private:
   explicit ScheduleTreeSequence(isl::ctx ctx)
       : ScheduleTree(ctx, {}, NodeType) {}
+  ScheduleTreeSequence(const ScheduleTreeSequence& eb) : ScheduleTree(eb) {}
 
  public:
-  ScheduleTreeSequence(const ScheduleTreeSequence& eb) : ScheduleTree(eb) {}
   virtual ~ScheduleTreeSequence() override {}
 
   bool operator==(const ScheduleTreeSequence& other) const;
@@ -224,6 +224,9 @@ struct ScheduleTreeSequence : public ScheduleTree {
   static std::unique_ptr<ScheduleTreeSequence> make(
       isl::ctx ctx,
       std::vector<ScheduleTreeUPtr>&& children = {});
+  static std::unique_ptr<ScheduleTreeSequence> make(
+      const ScheduleTreeSequence* tree,
+      std::vector<ScheduleTreeUPtr>&& children = {});
 
   virtual std::ostream& write(std::ostream& os) const override;
 };