[Attributor][FIX] Avoid dangling value pointers during code modification
When we replace instructions with unreachable we delete instructions. We
now avoid dangling pointers to those deleted instructions in the
`ToBeChangedToUnreachableInsts` set. Other modification collections
might need to be updated in the future as well.
diff --git a/llvm/lib/Transforms/IPO/Attributor.cpp b/llvm/lib/Transforms/IPO/Attributor.cpp
index 13fcf6a..b3b9e1e 100644
--- a/llvm/lib/Transforms/IPO/Attributor.cpp
+++ b/llvm/lib/Transforms/IPO/Attributor.cpp
@@ -5668,8 +5668,9 @@
}
}
}
- for (Instruction *I : ToBeChangedToUnreachableInsts)
- changeToUnreachable(I, /* UseLLVMTrap */ false);
+ for (auto &V : ToBeChangedToUnreachableInsts)
+ if (Instruction *I = dyn_cast_or_null<Instruction>(V))
+ changeToUnreachable(I, /* UseLLVMTrap */ false);
for (Instruction *I : TerminatorsToFold)
ConstantFoldTerminator(I->getParent());