IMA vs tree-ssa

[Joe Buck]

Mark Mitchell <mark@codesourcery.com> writes:
> | I strongly expect that their intention was to create a requirement
> | that compatibility be an equivalence relation.

I'm just going to highlight one section of Gaby's reply:
On Mon, Mar 08, 2004 at 11:57:00PM +0100, Gabriel Dos Reis wrote:
>        [#2] All declarations that  refer  to  the  same  object  or
>        function shall have compatible type; otherwise, the behavior
>        is undefined.

This would seem to suggest that in the situations where non-transitive
behavior would otherwise result (for example, an incomplete struct type is
compatible with two distinct and incompatible definitions of that struct
type), and this matters (for the purpose of aliasing analysis, for
example), we have undefined behavior, so the compiler should be able to
act as though this situation does not arise and assume transitivity.