[tz] Minor (unimportant really) technical UB bug in strftime() ?
Paul Eggert
eggert at cs.ucla.edu
Thu Nov 10 00:29:18 UTC 2022
On 11/9/22 15:34, Guy Harris via tz wrote:
> Does the C specification allow for a C implementation on a hypothetical load-store architecture machine in which:
>
> a byte is 8 bits plus an "initialized bit";
>
> the "uninitialize" instruction has a memory-location operand, and clears the initialized bit;
>
> a store instruction set the initialized bit on all bytes to which it stores;
>
> a load instruction traps if any of the bytes from which it's loading doesn't have the initialized bit set?
No, not if memcpy is implemented via load+store. The C standard says
memcpy is supposed to work even if its source bytes are uninitialized.
(This was news to me until today, and I'm not a fan of this part of the
standard.)
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