Re: [patch 10/10] debug-early merge: compiler proper

[Jason Merrill <jason@redhat.com>]

On 05/29/2015 02:42 PM, Aldy Hernandez wrote:
> unsigned int i=555;
>
> int main()
> {
>    unsigned int array[i];
>    ...
> }
>
> For the VLA, I'd like to check if we have an array type with a missing
> DW_AT_{upper,lower}_bound late in the game, and fill it in.
>
> During early dwarf we only have an uninitialized gimple register
> representing the bound

Ah, I see, from gimplify_type_sizes.

> and loc_list_from_tree() cannot find the RTL
> with the final bound location.  Thus, we end up with a missing bound,
> which I propose to fill in late dwarf.

OK, that makes sense.  I wonder if we should emit debug info for the 
gimple register; that would allow us to fill in the bound during early 
dwarf.

> Obviously I was doing some nonsense with TYPE_SIZE != INTEGER_CST, when
> in reality I should probably check that TREE_CODE (type) == ARRAY_TYPE
> and that we are missing the bound late (by looking for DW_AT_*_bound in
> the cached DIE).

But this sounds reasonable.

Jason