[CoreFoundation] Fix incorrect cast in _CFRuntimeCreateInstance. #1806
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_cfinfoa field of CFRuntimeBase is an _Atomic(uint64_t), but for some reason it was being accessed from a uint32_t pointer (which I think violates strict aliasing rules). This was working for little endian architectures, but would have failed for big endian architectures when writing the value back into the MSB instead of the LSB. The fix uses the right size (64 bits) and removes the castings where possible. However, to avoid the _Atomic to be honored, the field is still casted to an uint64_t, which might hide future errors (like the situation this is trying to fix).
compnerd
reviewed
Dec 13, 2018
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@swift-ci please test |
compnerd
approved these changes
Dec 17, 2018
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_cfinfoa field of CFRuntimeBase is an _Atomic(uint64_t), but for some
reason it was being accessed from a uint32_t pointer (which I think
violates strict aliasing rules). This was working for little endian
architectures, but would have failed for big endian architectures when
writing the value back into the MSB instead of the LSB.
The fix uses the right size (64 bits) and removes the castings where
possible. However, to avoid the _Atomic to be honored, the field is
still casted to an uint64_t, which might hide future errors (like the
situation this is trying to fix).