[C++11] Add predecessors(BasicBlock *) / successors(BasicBlock *) iterator ranges.

Summary: This patch introduces two new iterator ranges and updates existing code to use it.  No functional change intended.

Test Plan: All tests (make check-all) still pass.

Reviewers: dblaikie

Reviewed By: dblaikie

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D4481

llvm-svn: 213474

3 files changed, 4 insertions, 7 deletions

diff --git a/llvm/lib/IR/BasicBlock.cpp b/llvm/lib/IR/BasicBlock.cpp
index ba07433103b..8ddcf25fced 100644
--- a/llvm/lib/IR/BasicBlock.cpp
+++ b/llvm/lib/IR/BasicBlock.cpp
@@ -321,10 +321,9 @@ BasicBlock *BasicBlock::splitBasicBlock(iterator I, const Twine &BBName) {
   // successors.  If there were PHI nodes in the successors, then they need to
   // know that incoming branches will be from New, not from Old.
   //
-  for (succ_iterator I = succ_begin(New), E = succ_end(New); I != E; ++I) {
+  for (BasicBlock *Successor : successors(New)) {
     // Loop over any phi nodes in the basic block, updating the BB field of
     // incoming values...
-    BasicBlock *Successor = *I;
     PHINode *PN;
     for (BasicBlock::iterator II = Successor->begin();
          (PN = dyn_cast<PHINode>(II)); ++II) {
diff --git a/llvm/lib/IR/Dominators.cpp b/llvm/lib/IR/Dominators.cpp
index d6649d6c706..f45543a4e71 100644
--- a/llvm/lib/IR/Dominators.cpp
+++ b/llvm/lib/IR/Dominators.cpp
@@ -179,9 +179,7 @@ bool DominatorTree::dominates(const BasicBlockEdge &BBE,
   // trivially dominates itself, so we only have to find if it dominates the
   // other predecessors. Since the only way out of X is via NormalDest, X can
   // only properly dominate a node if NormalDest dominates that node too.
-  for (const_pred_iterator PI = pred_begin(End), E = pred_end(End);
-       PI != E; ++PI) {
-    const BasicBlock *BB = *PI;
+  for (const BasicBlock *BB : predecessors(End)) {
     if (BB == Start)
       continue;
 
diff --git a/llvm/lib/IR/Verifier.cpp b/llvm/lib/IR/Verifier.cpp
index 9cf911b51a4..5b7a3475574 100644
--- a/llvm/lib/IR/Verifier.cpp
+++ b/llvm/lib/IR/Verifier.cpp
@@ -2107,8 +2107,8 @@ void Verifier::visitLandingPadInst(LandingPadInst &LPI) {
 
   // The landingpad instruction defines its parent as a landing pad block. The
   // landing pad block may be branched to only by the unwind edge of an invoke.
-  for (pred_iterator I = pred_begin(BB), E = pred_end(BB); I != E; ++I) {
-    const InvokeInst *II = dyn_cast<InvokeInst>((*I)->getTerminator());
+  for (BasicBlock *Pred : predecessors(BB)) {
+    const InvokeInst *II = dyn_cast<InvokeInst>(Pred->getTerminator());
     Assert1(II && II->getUnwindDest() == BB && II->getNormalDest() != BB,
             "Block containing LandingPadInst must be jumped to "
             "only by the unwind edge of an invoke.", &LPI);