Richard Guenther writes: > On Wed, 21 Dec 2005, Andrew Haley wrote: > > > Richard Guenther writes: > > > > > > 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? > > > > Look at Section 6.5.6, Para 8. The code is undefined. > > This talks about pointers that point to elements of an array > object. It does not talk about doing arithmetic on arbitrary > pointer (constants), which is what the code does. Or is a pointer > always pointing to elements of some array object (being it the > global heap "array object")?
Section 6.5.6, Para 8 always holds. If p1 is a valid pointer, then it points to a byte within an object or to an element just past the end of an array. Andrew.
