Frontends(eg. clang) might pass incomplete form of IR, to step off the way beyond iterator end. In the case I had met, it took infinite loop due to meeting bogus PHInode.
Thanks to Jay Foad and John McCall.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@137175
91177308-0d34-0410-b5e6-
96231b3b80d8
return;
for (unsigned i = 0, e = TI->getNumSuccessors(); i != e; ++i) {
BasicBlock *Succ = TI->getSuccessor(i);
- for (iterator II = Succ->begin(); PHINode *PN = dyn_cast<PHINode>(II);
- ++II) {
+ // N.B. Succ might not be a complete BasicBlock, so don't assume
+ // that it ends with a non-phi instruction.
+ for (iterator II = Succ->begin(), IE = Succ->end(); II != IE; ++II) {
+ PHINode *PN = dyn_cast<PHINode>(II);
+ if (!PN)
+ break;
int i;
while ((i = PN->getBasicBlockIndex(this)) >= 0)
PN->setIncomingBlock(i, New);