From: Igor Laevsky Date: Thu, 30 Nov 2017 15:41:58 +0000 (+0000) Subject: [FuzzMutate] Bailout from injecting into empty basic blocks. X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=4a8c2b625b7ed7d95e349cdd45ff6a3df0771bc5;p=llvm [FuzzMutate] Bailout from injecting into empty basic blocks. In rare cases we can receive request to inject into completelly empty basic block. In the normal case all basic blocks contain at least terminator instruction, but it is possible that the only instruction is catchpad instruction which is not part of the instruction iterator. This case seems rare enough to not care about it. Submiting without review, since it seems almost NFC. I couldn't come up with any reasonable way to test this. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@319444 91177308-0d34-0410-b5e6-96231b3b80d8 --- diff --git a/lib/FuzzMutate/IRMutator.cpp b/lib/FuzzMutate/IRMutator.cpp index 59f94716caa..15e7f86d1cd 100644 --- a/lib/FuzzMutate/IRMutator.cpp +++ b/lib/FuzzMutate/IRMutator.cpp @@ -105,6 +105,8 @@ void InjectorIRStrategy::mutate(BasicBlock &BB, RandomIRBuilder &IB) { SmallVector Insts; for (auto I = BB.getFirstInsertionPt(), E = BB.end(); I != E; ++I) Insts.push_back(&*I); + if (Insts.size() < 1) + return; // Choose an insertion point for our new instruction. size_t IP = uniform(IB.Rand, 0, Insts.size() - 1);