https://gcc.gnu.org/bugzilla/show_bug.cgi?id=87362
--- Comment #8 from Richard Biener <rguenth at gcc dot gnu.org> ---
(In reply to Richard Biener from comment #7)
> The following makes it work for a simple C int main() {}. It's also a little
> bit less hacky...
>
> Index: gcc/dwarf2out.c
> ===================================================================
> --- gcc/dwarf2out.c (revision 264418)
> +++ gcc/dwarf2out.c (working copy)
> @@ -26896,6 +26896,10 @@ dwarf2out_decl (tree decl)
> static void
> dwarf2out_function_decl (tree decl)
> {
> + if (in_lto_p)
> + /* This helps debuggers to build a symbol table. */
> + if (dw_die_ref die = lookup_decl_die (decl))
> + add_linkage_attr (die, decl);
> dwarf2out_decl (decl);
> call_arg_locations = NULL;
> call_arg_loc_last = NULL;
Doesn't seem to help gdb at all.
Maybe gdb pulls in all the early CUs because of the stray DIEs we have
for optimized out functions, like
<2><423bc64>: Abbrev Number: 5 (DW_TAG_subprogram)
<423bc65> DW_AT_abstract_origin: <0x3419cf1>
<423bc69> DW_AT_sibling : <0x423bc73>
<3><423bc6d>: Abbrev Number: 6 (DW_TAG_formal_parameter)
<423bc6e> DW_AT_abstract_origin: <0x3419cfe>
<3><423bc72>: Abbrev Number: 0
since we create them at tree streaming time rather than when actually
outputting them (PR83941). My idea for that is to create those lazily
somehow, like having dwarf2out_register_external_die populate an
on-the-side representation and lookup_decl_die querying that if the
DIE wasn't created already.
I also notice that breaking on a function doesn't seem to work (if there are
only inline/IPA optimized instances(?)). gdb doesn't stop.
auto-completion also takes ages. So whatever gdb does it isn't very
efficient ;)
