ScheduleTreeSet: hide copy constructor

ScheduleTree nodes are not supposed to be manipulated by-value, only via
unique pointers.  Make the copy constructor of ScheduleTreeSet 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

@@ -144,7 +144,7 @@ static std::unique_ptr<ScheduleTree> makeElem(const ScheduleTree& st) {
   ELEM_MAKE_CASE_CSTR(ScheduleTreeFilter)
   ELEM_MAKE_CASE_CSTR(ScheduleTreeMapping)
   ELEM_MAKE_CASE_CSTR(ScheduleTreeSequence)
-  ELEM_MAKE_CASE(ScheduleTreeSet)
+  ELEM_MAKE_CASE_CSTR(ScheduleTreeSet)
   ELEM_MAKE_CASE(ScheduleTreeThreadSpecificMarker)
 
 #undef ELEM_MAKE_CASE_CSTR

tc/core/polyhedral/schedule_tree_elem.cc

@@ -175,6 +175,14 @@ std::unique_ptr<ScheduleTreeSet> ScheduleTreeSet::make(
   return res;
 }
 
+std::unique_ptr<ScheduleTreeSet> ScheduleTreeSet::make(
+    const ScheduleTreeSet* tree,
+    std::vector<ScheduleTreeUPtr>&& children) {
+  auto res = std::unique_ptr<ScheduleTreeSet>(new ScheduleTreeSet(*tree));
+  res->appendChildren(std::move(children));
+  return res;
+}
+
 std::unique_ptr<ScheduleTreeBand> ScheduleTreeBand::make(
     isl::multi_union_pw_aff mupa,
     bool permutable,

tc/core/polyhedral/schedule_tree_elem.h

@@ -238,9 +238,9 @@ struct ScheduleTreeSet : public ScheduleTree {
 
  private:
   explicit ScheduleTreeSet(isl::ctx ctx) : ScheduleTree(ctx, {}, NodeType) {}
+  ScheduleTreeSet(const ScheduleTreeSet& eb) : ScheduleTree(eb) {}
 
  public:
-  ScheduleTreeSet(const ScheduleTreeSet& eb) : ScheduleTree(eb) {}
   virtual ~ScheduleTreeSet() override {}
 
   bool operator==(const ScheduleTreeSet& other) const;
@@ -251,6 +251,9 @@ struct ScheduleTreeSet : public ScheduleTree {
   static std::unique_ptr<ScheduleTreeSet> make(
       isl::ctx ctx,
       std::vector<ScheduleTreeUPtr>&& children = {});
+  static std::unique_ptr<ScheduleTreeSet> make(
+      const ScheduleTreeSet* tree,
+      std::vector<ScheduleTreeUPtr>&& children = {});
 
   virtual std::ostream& write(std::ostream& os) const override;
 };