Scalar: Remove remaining ilist iterator implicit conversions

Remove remaining `ilist_iterator` implicit conversions from
LLVMScalarOpts.

This change exposed some scary behaviour in
lib/Transforms/Scalar/SCCP.cpp around line 1770.  This patch changes a
call from `Function::begin()` to `&Function::front()`, since the return
was immediately being passed into another function that takes a
`Function*`.  `Function::front()` started to assert, since the function
was empty.  Note that `Function::end()` does not point at a legal
`Function*` -- it points at an `ilist_half_node` -- so the other
function was getting garbage before.  (I added the missing check for
`Function::isDeclaration()`.)

Otherwise, no functionality change intended.

llvm-svn: 250211

1 files changed, 3 insertions, 3 deletions

diff --git a/llvm/lib/Transforms/Scalar/PlaceSafepoints.cpp b/llvm/lib/Transforms/Scalar/PlaceSafepoints.cpp
index 3552dcdfa73..379d9639f91 100644
--- a/llvm/lib/Transforms/Scalar/PlaceSafepoints.cpp
+++ b/llvm/lib/Transforms/Scalar/PlaceSafepoints.cpp
@@ -423,14 +423,14 @@ static Instruction *findLocationForEntrySafepoint(Function &F,
     assert(hasNextInstruction(I) &&
            "first check if there is a next instruction!");
     if (I->isTerminator()) {
-      return I->getParent()->getUniqueSuccessor()->begin();
+      return &I->getParent()->getUniqueSuccessor()->front();
     } else {
-      return std::next(BasicBlock::iterator(I));
+      return &*++I->getIterator();
     }
   };
 
   Instruction *cursor = nullptr;
-  for (cursor = F.getEntryBlock().begin(); hasNextInstruction(cursor);
+  for (cursor = &F.getEntryBlock().front(); hasNextInstruction(cursor);
        cursor = nextInstruction(cursor)) {
 
     // We need to ensure a safepoint poll occurs before any 'real' call.  The