Re: ReactOS: stack vs heap

On Mon, Sep 4, 2023 at 3:39 PM Behdad Esfahbod <[email protected]> wrote:

> On Sat, Sep 2, 2023 at 12:31 AM Alexei Podtelezhnikov <[email protected]>
> wrote:
>
>> >
>> > Wanted to point out that compiling with gcc and adding
>> "-stack-usage=2000" to get reports about stacks larger than 2000 bytes is
>> probably the easiest way to track down large stacks at the moment. Note
>> that af_cjk_metrics_init_widths (44480 bytes) and
>> af_latin_metrics_init_widths (52992 bytes) are by far the largest.
>> cf2_interpT2CharString (27520 bytes) is also surprisingly large. There are
>> a few others like the rasterizer stacks that are between 10-20kb which one
>> may also want to look into, but these have been less problematic on my
>> experience (though that may have been due to the even larger stacks being
>> allocated first). Just wanted to point out how to measure and that the
>> rasterizer might not be the first place to look.
>>
>> That is surprisingly large. Someone should examine how much of it is
>> actually used. The rendering pool of "visited cells" (pixels) is
>> rather predictable for a given outline. That is why it is easy for me.
>>
>
> I took a look at the autohinter one. The problem comes from:
>
> AF_LatinBlueRec  blues[AF_BLUE_STRINGSET_MAX];
>
> in struct  AF_LatinAxisRec_. The value of AF_BLUE_STRINGSET_MAX is ~260.
>
> My gut feeling is that that's a typo and should be:
>
>  AF_LatinBlueRec  blues[AF_BLUE_STRINGSET_MAX_LEN];
>
> where AF_BLUE_STRINGSET_MAX_LEN is 8. I haven't tested that.
>

Same thing in afcjk.h.

I'm finding these using:

$ make CPPFLAGS=-Wframe-larger-than=4096