Re: GNU coding standards

[Bruno Haible]

Alfred M. Szmidt wrote:
> the chapter on K&R C is a suggestion if you need
> to support it so there is no harm in having it included.

I agree with Martin:

  * K&R C compilers (i.e. compilers that don't support ANSI C from 1989)
    are not in use any more. In Gnulib, we have dropped support for such
    compilers in 2011, and no one complained.

  * The most recent gcc and clang compilers, when used with option -std=gnu23,
    warn about K&R C functions definitions:

       ==================== foo.c ===================
       int foo (x, y) int x; int y; { return x - y; }
       ==============================================
       $ gcc -std=gnu23 -S foo.c
       foo.c: In function ‘foo’:
       foo.c:1:5: warning: old-style function definition 
[-Wold-style-definition]
           1 | int foo (x, y) int x; int y; { return x - y; }
             |     ^~~
       $ clang -std=gnu23 -S foo.c
       foo.c:1:10: error: unknown type name 'x'
           1 | int foo (x, y) int x; int y; { return x - y; }
             |          ^
       foo.c:1:13: error: unknown type name 'y'
           1 | int foo (x, y) int x; int y; { return x - y; }
             |             ^
       foo.c:1:15: error: expected ';' after top level declarator
           1 | int foo (x, y) int x; int y; { return x - y; }
             |               ^
             |               ;
       foo.c:1:30: error: expected identifier or '('
           1 | int foo (x, y) int x; int y; { return x - y; }
             |                              ^

    This option -std=gnu23 will become the default in the future, like
    -std=gnu99 and later -std=gnu11 became the default.

    Therefore the harm of this section is that it suggests a code style
    that we know is not future-proof.

Bruno