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Re: [External] : M-. vs C-h o
From: |
Hongyi Zhao |
Subject: |
Re: [External] : M-. vs C-h o |
Date: |
Fri, 22 Oct 2021 10:43:00 +0800 |
On Fri, Oct 22, 2021 at 10:31 AM Óscar Fuentes <ofv@wanadoo.es> wrote:
>
> Hongyi Zhao <hongyi.zhao@gmail.com> writes:
>
> > Thank you for pointing this out. I've `rg'ed the local Emacs git
> > source code repo, and it seems still difficult to pinpoint the
> > corresponding C source code implementation of DEFUN.
> >
> > HZ
>
> DEFUN is a macro. If you search for
>
> #define DEFUN
>
> you will find it in src/lisp.h
Do you mean the following search result?
$ rg -A17 -B27 -uu '#define DEFUN\(lname' src/
src/lisp.h
3022-/* Define a built-in function for calling from Lisp.
3023- `lname' should be the name to give the function in Lisp,
3024- as a null-terminated C string.
3025- `fnname' should be the name of the function in C.
3026- By convention, it starts with F.
3027- `sname' should be the name for the C constant structure
3028- that records information on this function for internal use.
3029- By convention, it should be the same as `fnname' but with S
instead of F.
3030- It's too bad that C macros can't compute this from `fnname'.
3031- `minargs' should be a number, the minimum number of arguments allowed.
3032- `maxargs' should be a number, the maximum number of arguments allowed,
3033- or else MANY or UNEVALLED.
3034- MANY means pass a vector of evaluated arguments,
3035- in the form of an integer number-of-arguments
3036- followed by the address of a vector of Lisp_Objects
3037- which contains the argument values.
3038- UNEVALLED means pass the list of unevaluated arguments
3039- `intspec' says how interactive arguments are to be fetched.
3040- If the string starts with a `(', `intspec' is evaluated and
the resulting
3041- list is the list of arguments.
3042- If it's a string that doesn't start with `(', the value should follow
3043- the one of the doc string for `interactive'.
3044- A null string means call interactively with no arguments.
3045- `doc' is documentation for the user. */
3046-
3047-/* This version of DEFUN declares a function prototype with the right
3048- arguments, so we can catch errors with maxargs at compile-time. */
3049:#define DEFUN(lname, fnname, sname, minargs, maxargs, intspec, doc) \
3050- SUBR_SECTION_ATTRIBUTE \
3051- static union Aligned_Lisp_Subr sname = \
3052- {{{ PVEC_SUBR << PSEUDOVECTOR_AREA_BITS }, \
3053- { .a ## maxargs = fnname }, \
3054- minargs, maxargs, lname, {intspec}, 0}}; \
3055- Lisp_Object fnname
3056-
3057-/* defsubr (Sname);
3058- is how we define the symbol for function `name' at start-up time. */
3059-extern void defsubr (union Aligned_Lisp_Subr *);
3060-
3061-enum maxargs
3062- {
3063- MANY = -2,
3064- UNEVALLED = -1
3065- };
3066-
HZ
Re: M-. vs C-h o, Eli Zaretskii, 2021/10/22