Re: [9fans] C99

["Douglas A. Gwyn" <DAGwyn@null.net>]

Russ Cox wrote:
> http://www.dkuug.dk/JTC1/SC22/WG14/www/docs/n843.ps.gz

That's not an accurate copy of the 1999 C standard.
Jack Klein just posted information in comp.lang.c.moderated
about obtaining a correct copy.

There are several sources for a summary of the main changes
from C89 to C99, e.g.
http://web.onetelnet.ch/~twolf/tw/c/c9x_changes.html

The preprocessor extensions are easy enough to implement,
except possibly for the variable-number-of-arguments facility.

Several of the extensions to the language proper are either
already in Plan 9's compiler (compound literals, designated
initializers) or else are straightforward to add.  Variable-length
arrays might be harder.

Most of the library extensions are straightforward to add.
For a start at providing some C99 standard library facilities,
e.g. <stdbool.h> and <stdint.h>, see
http://www.lysator.liu.se/c/q8/index.html
The most difficult one is undoubtedly <tgmath.h>, which
requires compiler support.

My opinion as a long-time implementor and maintainer of C
environments is that *most* of the changes from C89 to C99
can be implemented merely by taking the time to do it,
without having to think very hard, and just a few features
require special care (VLAs, <tgmath.h>).  Until C99 conforming
implementations reach the marketplace and start to be used,
there won't be any demand for the new features.  That means
in probably another year or two it would be useful to have C99
support ready.