Fwd: Re: [Patch, fortran] PR69498 Fix ICE on unexpected submodule

[Thomas Koenig]

Hi Nicolas,

> as far as I understand this bug it has little to do with the SUBMODULE
> being in the wrong place (the subject of this mail was a bit
> misleading). The problem is that after calling
> gfc_restore_last_undo_checkpoint() it doesn't clean the symtree properly
> if there is a SUBMODULE statement, because it calls gfc_delete_symtree()
> with the name of the symbol whose symtree node should be deleted. But
> there no longer is a symtree node with the same name as the symbol,
> since the symbol has been renamed in module.c:794(gfc_match_submodule)
> from 'submod' to 'mod.submod'. This leaves the symtree with a node that
> points to a released symbol. I think the best way to ensure that this
> node is deleted is just to ignore everything before the dot in
> gfc_delete_symtree() as in the suggested patch, but there might be far
> better ways.
>
> Nicolas
>
> P.S.: The case only crashes because the compiler later creates a new
> symbol at the exact same place as the submodule symbol. It then proceeds
> to crash because the refs count no longer matches. Made debugging fun :D

The patch is OK, unless somebody objects in the next day or so.

Regards

	Thomas