> This fixes the Ada bootstrap failure introduced by alloca folding. > We now fold alloca (0) to &auto-with-size-zero which confuses us. > I didn't exactly investigate but what I think happens is that we > expand that &auto-with-size-zero to NULL instead of > virtual_stack_dynamic_rtx (see zero-size special-case in > allocate_dynamic_stack_space) and Ada ends up dereferencing the > pointer returned from alloca (0) (something to investigate for > the Ada folks I guess), something which "works" if we just > return a random stack address.
Thanks! In Ada, it's quite natural to end up with a dynamically sized object of size 0. For instance, if you declare an array with a dynamic bound: Table : Unit_Table (1 .. Last_Unit); and Last_Unit happens to be 0 at run-time Arno
