Fix use-after-free of deleted debug instructions in Canonicalize

Author: meg-gupta

lib/SILOptimizer/Utils/CanonicalizeInstruction.cpp

@@ -26,6 +26,7 @@
 #include "swift/SIL/SILFunction.h"
 #include "swift/SIL/SILInstruction.h"
 #include "swift/SILOptimizer/Analysis/SimplifyInstruction.h"
+#include "swift/SILOptimizer/Utils/DebugOptUtils.h"
 #include "llvm/ADT/Statistic.h"
 #include "llvm/Support/Debug.h"
 
@@ -521,7 +522,7 @@ eliminateUnneededForwardingUnarySingleValueInst(SingleValueInstruction *inst,
   for (auto *use : getNonDebugUses(inst))
     if (!isa<DestroyValueInst>(use->getUser()))
       return next;
-  deleteAllDebugUses(inst);
+  deleteAllDebugUses(inst, pass.callbacks);
   SILValue op = inst->getOperand(0);
   inst->replaceAllUsesWith(op);
   pass.notifyHasNewUsers(op);

test/SILOptimizer/sil_combine_ossa.sil

@@ -4561,3 +4561,19 @@ bb1(%2 : @owned $FakeOptional<Builtin.NativeObject>):
   %9999 = tuple()
   return %9999 : $()
 }
+
+// CHECK-LABEL: sil [ossa] @test_useafterfree_debuginstdelete :
+// CHECK-NOT: upcast
+// CHECK-NOT: unchecked_ref_cast
+// CHECK-LABEL: } // end sil function 'test_useafterfree_debuginstdelete'
+sil [ossa] @test_useafterfree_debuginstdelete : $@convention(method) (@owned E) -> () {
+bb0(%0 : @owned $E):
+  %1 = upcast %0 : $E to $B
+  debug_value %1 : $B
+  %2 = unchecked_ref_cast %1 : $B to $Builtin.NativeObject
+  debug_value %2 : $Builtin.NativeObject
+  destroy_value %2 : $Builtin.NativeObject
+  %res = tuple ()
+  return %res : $()
+}
+