Subject: bug#2203: C Mode: C-M-a fails at BOD re_comp, src/regex.c L6534

From: Alan J Third <[email-masked]>
Date: Fri, 15 Jan 2016 20:40:31 +0000

Alan Mackenzie <[email-masked]> writes:

> In .../src/regex.c put point at BOL6534, "char *" here:
>
> }
> WEAK_ALIAS (__re_compile_pattern, re_compile_pattern)
> ^L
> /* Entry points compatible with 4.2 BSD regex library.  We don't define
>    them unless specifically requested.  */
>
> #if defined _REGEX_RE_COMP || defined _LIBC
>
> /* BSD has one and only one pattern buffer.  */
> static struct re_pattern_buffer re_comp_buf;
>
> char *                                          <=================================
> # ifdef _LIBC
> /* Make these definitions weak in libc, so POSIX programs can redefine
>    these names if they don't use our functions, and still use
>    regcomp/regexec below without link errors.  */
> weak_function
> # endif
> re_comp (s)
>     const char *s;
> {
>
>
> Do C-M-a.  Point doesn't move.
>
> Preliminary investigation:  With point on the 'h' of "char *",
> (c-beginning-of-decl-1 nil) should move point one character backwards.
> Instead, it moves to BOL "WEAK_ALIAS".

I just tested this in Emacs 25 and it seems that in every case point
moves back to "WEAK_ALIAS". That is, C-M-a, c-beginning-of-defun,
behaves the same way as (c-beginning-of-decl-1 nil).

I guess that makes it more broken, if more consistent, than when the bug
was raised.

-- 
Alan Third