Re: Correct byte compiler error/warning positions. The solution!

[Alan Mackenzie <acm@muc.de>]

Hello, Andrea.

On Wed, Dec 01, 2021 at 17:53:03 +0000, Andrea Corallo wrote:
> Eli Zaretskii <eliz@gnu.org> writes:

> [...]

> > If all the benchmarks show a slowdown <= 1%, I'm okay with merging it.

> > Thanks.

> Another quick note, I think we should evaluate the impact not only with
> different benchmarks but also using a native compiled build (ATM the
> branch has no support for that).

The change to the scratch/correct-warning-pos branch to work with native
compilation is probably quite small, but I don't know the native code
compiler (comp.el, etc.) at all.

Would you help me with it, please.

The mechanism of the change was introducing @dfn{symbols with position}.
These are embodied in src/lisp.h with a new type tag
PVEC_SYMBOL_WITH_POS, and the type struct Lisp_Symbol_With_Pos.

The most pertinent changes in the branch are likewise those in
src/lisp.h.  There, there's a new flag variable,
symbols_with_pos_enabled, which is tested in the macros lisp_h_EQ,
lisp_h_SYMBOLP, and in the inline function XSYMBOL.  There are new
"primitive" macros, lisp_h_BASE_EQ, lisp_h_BARE_SYMBOL_P, and the inline
function XBARE_SYMBOL.  There are a few other things too, like
lisp_h_SYMBOL_WITH_POS_P.

All these changes can be seen with a git diff between the branch head
and the branch point in the master branch.

Thanks in advance for the help!

> Thanks

>   Andrea

-- 
Alan Mackenzie (Nuremberg, Germany).