https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107361
Peter Kasting <pkasting at google dot com> changed:
What |Removed |Added
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CC| |pkasting at google dot com
--- Comment #3 from Peter Kasting <pkasting at google dot com> ---
This warning fired in Chromium on safe code that clang doesn't warn about, for
similar reasons as the reporter here complains about.
I think the linked patch was too aggressive. At the very least, `memcpy()` from
some instance `t1` of a `T` into another instance `t2` of a `T` should only
require that `T` is trivially-copyable. Since we can assume that `t1`'s
invariants held before the statement, after it `t2`'s invariants must hold (or
the coder should not have allowed trivial copyability, which is a distinct
bug).
I do agree with the original patch author that `memset()` probably requires the
type to be trivial rather than just trivially-copyable.
We can work around with cast-to-`void*` prior to `memcpy()`, which feels
unfortunate given that the intent of that is less obvious to a reader, and it's
probably easier to introduce dangerous behavior later.
