Possible gcc bug in strict type aliasing

[Vincent Lefevre]

On 2016-09-26 17:28:38 +0300, Alexander Monakov wrote:
> I concede the original example may invoke UB if the first write to
> malloc'ed region determines its type until free().

No, the effective type is determined by the last write, not the
first one. The C standard says (6.5#6): "[...] the type of the
lvalue becomes the effective type of the object for that access
and for subsequent accesses that do not modify the stored value."
                            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

So, the effective type of an object is allowed to change.

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