[PATCH] D30423: [ubsan] Detect UB loads from bitfields

[Vedant Kumar via Phabricator via cfe-commits]

vsk added inline comments.


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Comment at: test/CodeGenCXX/ubsan-bitfields.cpp:21
+  // CHECK: call void @__ubsan_handle_load_invalid_value
+  return s->e1;
+}
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vsk wrote:
> arphaman wrote:
> > Can we avoid the check if the bitfield is 2 bits wide?
> I don't think so, because if the user memset()'s the memory backing the struct, we could still load a value outside of {1, 2, 3} from the bitfield.
Sorry, I misread your question as 'if the enum can be represented in 2 bits'. You're right, the check can be skipped if the _bitfield_ is 2 bits wide. I think this can be handled along with the 1-bit unsigned BOOL case in a follow up.


https://reviews.llvm.org/D30423