[PATCH] D48899: [dsymutil] Convert recursion in lookForDIEsToKeep into worklist.

[David Blaikie via Phabricator via llvm-commits]

dblaikie added inline comments.


================
Comment at: llvm/tools/dsymutil/DwarfLinker.cpp:878-880
+    std::vector<DWARFDie> Children(Current.Die.begin(), Current.Die.end());
+    std::reverse(Children.begin(), Children.end());
+    for (auto Child : Children)
----------------
JDevlieghere wrote:
> friss wrote:
> > Can you use something like make_reverse_iterator to avoid copying the list?
> The iterator is a forward iterator (it uses getSibling to advance) so unfortunately not. 
I think, maybe, getPreviousSibling could be implemented without great cost & this could be made into a bidirectional iterator? (looks like getSibling works by scanning forward in the list of DIEs until it finds another DIE with the same depth (or bailing out if it finds a DIE with a shallower depth) - the reverse search coudl be done the same way, I think?)


================
Comment at: llvm/tools/dsymutil/DwarfLinker.cpp:883-884
+    SmallVector<DWARFDie, 4> Children(Current.Die.begin(), Current.Die.end());
+    for (auto Child = Children.rbegin(), End = Children.rend(); Child != End;
+         ++Child)
+      Worklist.emplace_back(*Child, Current.Flags);
----------------
  for (... : reverse(Children))

perhaps?


https://reviews.llvm.org/D48899