Re: [PATCH v3 8/9] gdb/ctf: don't use psymtabs, create symtabs directly

Simon Marchi
2026-03-09T18:52:11Z

On 3/4/26 2:29 PM, Tom Tromey wrote:
>>>>>> "Simon" == Simon Marchi <simon.marchi@efficios.com> writes:
>
> Simon> My hypothesis is that CTF debug info is typically small enough and fast
> Simon> enough to process that it's not worth it to bother with an intermediate
> Simon> step before full symbols. But I will need help to see if this is true,
> Simon> I'm not sure what representatively big C project I can build with CTF
> Simon> debug info.
>
> Is there even a (source-available) pure C program bigger than the kernel?

No idea.

> Simon> GDB is still able to load the resulting ELF, and there are about 150k
> Simon> calls to ctf_add_type_cb. Before this patch, elfctf_build_psymtabs
> Simon> takes anywhere between 300-350 ms. With this patch, it's around 400 ms.
>
> This seems completely acceptable to me.
>
> Simon> In order to access the symtabs, elfctf_build_symtabs installs the
> Simon> expanded_symbols_functions quick_symbol_functions implementation, which
> Simon> essentially searches in the existing symtabs. I am pretty sure this is
> Simon> not 100% correct, because this would search unrelated symtabs, if for
> Simon> instance the CTF debug info co-existed with DWARF info. But it's good
> Simon> enough for a prototype.
>
> In light of patch #7 this paragraph is obsolete.

Thanks, removed locally.

Simon