[DeadObjectElim] Bail on invalid access path.

rdar://162237650

Author: nate-chandler

lib/SILOptimizer/Transforms/DeadObjectElimination.cpp

@@ -351,6 +351,8 @@ static bool onlyStoresToTailObjects(BuiltinInst *destroyArray,
 
  // Check if the destroyArray destroys the tail elements of allocRef.
  auto destroyPath = AccessPath::compute(destroyArray->getArguments()[1]);
+ if (!destroyPath.isValid())
+ return false;
  AccessStorage storage = destroyPath.getStorage();
  if (auto *beginDealloc = dyn_cast<BeginDeallocRefInst>(storage.getRoot())) {
  destroyPath = AccessPath(

validation-test/SILOptimizer/rdar162237650.swift

@@ -0,0 +1,17 @@
+// RUN: %target-swift-frontend -c -O %s -target %target-swift-6.0-abi-triple
+
+// REQUIRES: synchronization
+
+import Synchronization
+
+class Locked<T> {
+ let mutex: Mutex<T>
+
+ init(_ rawValue: T) {
+ mutex = Mutex(rawValue)
+ }
+}
+
+class Foo {}
+
+_ = Locked(Foo())