GraphTraits: Add range versions of graph traits functions (graph_nodes, graph_children, inverse_graph_nodes, inverse_graph_children).

Summary:
Convert all obvious node_begin/node_end and child_begin/child_end
pairs to range based for.

Sending for review in case someone has a good idea how to make
graph_children able to be inferred. It looks like it would require
changing GraphTraits to be two argument or something. I presume
inference does not happen because it would have to check every
GraphTraits in the world to see if the noderef types matched.

Note: This change was 3-staged with clang as well, which uses
Dominators/etc from LLVM.

Reviewers: chandlerc, tstellarAMD, dblaikie, rsmith

Subscribers: arsenm, llvm-commits, nhaehnle

Differential Revision: https://reviews.llvm.org/D29767

llvm-svn: 294620

1 files changed, 1 insertions, 4 deletions

diff --git a/llvm/lib/Analysis/IteratedDominanceFrontier.cpp b/llvm/lib/Analysis/IteratedDominanceFrontier.cpp
index d1374acd963..27249664bce 100644
--- a/llvm/lib/Analysis/IteratedDominanceFrontier.cpp
+++ b/llvm/lib/Analysis/IteratedDominanceFrontier.cpp
@@ -64,10 +64,7 @@ void IDFCalculator<NodeTy>::calculate(
       BasicBlock *BB = Node->getBlock();
       // Succ is the successor in the direction we are calculating IDF, so it is
       // successor for IDF, and predecessor for Reverse IDF.
-      for (auto SuccIter = GraphTraits<NodeTy>::child_begin(BB),
-                End = GraphTraits<NodeTy>::child_end(BB);
-           SuccIter != End; ++SuccIter) {
-        BasicBlock *Succ = *SuccIter;
+      for (auto *Succ : graph_children<NodeTy>(BB)) {
         DomTreeNode *SuccNode = DT.getNode(Succ);
 
         // Quickly skip all CFG edges that are also dominator tree edges instead