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Re: PR 25512: pointer overflow defined?
Robert Dewar <dewar@adacore.com> writes:
| Richard Guenther wrote:
|
| >The problem in this PR is that code like in the testcase (from OpenOffice)
| >assumes that pointer overflow is defined. As the standard does not talk
| >about wrapping pointer semantics at all (at least I couldn't find anything
| >about that), how should we treat this?
| >
| How could pointer arithmetic overflow, the result must be within the
| same allocated object (or just past it in the array case, and if necessary
It highly depends on what you define to be pointer arithmetic.
Given the conversions
pointer -> integer type
integer type -> pointer
T* -> U*
I think your sentence is way to restrictive and does not capture C
models.
Richard, to resolve this issue, we need to be more precise about our
mappings for
pointer -> integer type
integer type -> pointer
T* -> U*
conversions. This is not an issue to resolved in isolation, piece meal.
-- Gaby