This is the mail archive of the
mailing list for the GCC project.
Re: [patch] fix wrong gimple code with ptr to forward vla
Richard Kenner wrote:
I think I understand why the heuristic works, in practice. It's based
on Richard's explanation, which assumes an Ada-like language in which
types are elaborated at a well-defined point.
I don't follow that comment. It would seem to me that in *any*
language where you have a definition of a type that involves
variables, you have a be able to specify which value of the variable
is used, meaning that you have to elaborate the type at a well-defined
Yes -- but that doesn't necessarily correspond to a type-declaration, as
signified by a TYPE_DECL.
Your approach is imposing TYPE_DECLs on front ends. Joseph's is
requiring front ends to make clear when things are evaluated.
Joseph's approach is more explicit, and therefore more flexible; some
languages might require that array bounds be evaluated in a particular
order, for example, so that the equivalent of "int x[f()][g()];" had
well-defined behavior. A TYPE_DECL for an ARRAY_TYPE with the obvious
bounds doesn't make that explicit. So, the front end would need to
expand things anyhow; Joseph (and I) think we might as well just require
that the front end always do that.
(650) 331-3385 x713