Re: on the irresponsibility of pursuing C language reform

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From: Alejandro Colomar <[email protected]>
To: Keith Bostic <[email protected]>
Cc: Sam James <[email protected]>, 
	"G. Branden Robinson" <[email protected]>, Joseph Myers <[email protected]>, [email protected], 
	Mark Harris <[email protected]>, Nevin Liber <[email protected]>, 
	JeanHeyd Meneide <[email protected]>, Christopher Bazley <[email protected]>, 
	"Serge E. Hallyn" <[email protected]>, Iker Pedrosa <[email protected]>, 
	"Evgeny Grin (Karlson2k)" <[email protected]>, Kees Cook <[email protected]>, [email protected], 
	[email protected], Douglas McIlroy <[email protected]>
Subject: Re: on the irresponsibility of pursuing C language reform
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Hi Keith,

> Date: 2026-08-01 15:22:49-0700
> From: Keith Bostic <[email protected]>
>
> On Sat, Aug 1, 2026 at 10:09=E2=80=AFAM Alejandro Colomar <[email protected]=
> wrote:
>=20
>=20
> Well, Keith Bostic wouldn't have suggested that I do this change, and
> Branden wouldn't be defending that it might make sense to make this
> change.
>=20
>=20
> Since my name came up: I did suggest man page changes, and I should have
> been clearer about what I meant.

Thanks!

> I generally think innovation should happen in releases, in response to the
> user base. That=E2=80=99s the model with the better track record. Somebod=
y ships
> something, users adopt it or they don=E2=80=99t, and the standards codify=
 existing
> practice once it reaches consensus. When the standards bodies invent
> instead of codify, results have been uneven.

Fully agreed.

> So if glibc added <nonstring.h> tomorrow, that=E2=80=99s the system worki=
ng. Ship
> it, let people vote with their code, and let the standard adopt if it wan=
ts.
>=20
> But as I understand it, the man-pages project doesn=E2=80=99t control the=
 code it
> documents. It describes glibc and the kernel, it doesn=E2=80=99t ship the=
m. A
> documentation project changing how coding should work in a release it
> doesn=E2=80=99t control feels different to me. So, my opinion is the man =
pages
> shouldn=E2=80=99t be changing the standard includes.

Actually, the documentation is for the system, not the standard.  The
system does provide <memory.h>, and thus it's fair game to document it,
I believe.

> Advocating for better usage in the documentation is a different thing, and
> a good thing. The man pages can even go pretty hard, that=E2=80=99s their=
 job:
> =E2=80=9CNotice the include file is string.h. That=E2=80=99s an historic =
accident
> maintained for compatibility reasons; don=E2=80=99t let that fool you, th=
is
> function doesn=E2=80=99t operate on strings.=E2=80=9D

Indeed.  That's in essence what I'll do, with different wording.

The SYNOPSIS is the way of saying "don't let other sources fool you,
this function doesn't work on strings, and you should include the
system's <memory.h> to get it, which is compatible with all versions of
libc".

The NOTES section is the way of documenting "but the standard says
something different; let's ignore it".

	--- HEAD^:man/man3/strdupa.3
	+++ HEAD:man/man3/strdupa.3
	@@ -11,6 +11,10 @@ SYNOPSIS
	      #include <string.h>
	=20
	      char *strdupa(const char *s);
	+
	+     #define _GNU_SOURCE  /* See feature_test_macros(7) */
	+     #include <memory.h>
	+
	      char *strndupa(size_t n;
			    const char s[n], size_t n);
	=20
	@@ -48,6 +52,9 @@ STANDARDS
	 HISTORY
	      GNU.
	=20
	+NOTES
	+     The following header also provides strndupa(): <string.h>.
	+
	 SEE ALSO
	      alloca(3), strdup(3), strndup(3)
	=20
> That teaches the reader what the function actually does without relabeling
> where it lives. I think it=E2=80=99s roughly what Joseph is suggesting as=
 well,
> aiming the clarification at the reader=E2=80=99s understanding rather tha=
n at the
> SYNOPSIS line.

I should probably expand the NOTES a little bit, to be more clear about
why we ignore the standard in the SYNOPSIS.


Have a lovely night!
Alex

>=20
> =E2=80=94keith
> [email protected]

--=20
<https://www.alejandro-colomar.es>

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