status of C99 support in GCC?

status of C99 support in GCC?

[Gary Funck]

(I also posted this to gcc-help, but perhaps this is a more
relevant forum.)

Couple of questions:

- do you know of a handy, online document that summarizes the
differences between the ANSI/ISO 1999 C language specification
and its predecessor 1989 specification?j

- does GCC 2.95.2 support some/all of the C99 extensions? If gcc
does offer C99 support, where is this described?


I found this brief mention on GCC projects page,
http://gcc.gnu.org/projects.html

Changes to support C99 standard
-------------------------------
The new version of the C standard (ISO/IEC 9899:1999) requires a number
of library changes; these have to be provided by the C library, and not
by gcc. In addition, there are also changes to the language proper, and
some compiler support is needed for the new library features. An
overview of the C99 implementation status is available.

which cross-references this document,
http://gcc.gnu.org/c99status.html
giving status, but I was uncertain as to whether this reflects
only the state of the development version of GCC, or a stable release,
like 2.95.2 - no version information is given.

- what are the plans to support C99 in GCC?  What version/timeframe is
likely to offer this support?

Re: status of C99 support in GCC?

[Joseph S. Myers]

On Mon, 30 Oct 2000, Gary Funck wrote:

> - do you know of a handy, online document that summarizes the
> differences between the ANSI/ISO 1999 C language specification
> and its predecessor 1989 specification?j

Apart from the list of new features which is copied into c99status.html,
no - but you may wish to look at the Rationale (linked to from
http://gcc.gnu.org/readings.html ).

> - does GCC 2.95.2 support some/all of the C99 extensions? If gcc
> does offer C99 support, where is this described?

Not much (notwithstanding that the GCC 2.95 release notes link to
c99status.html - details of what was present when weren't being tracked at
that point).

The support in current CVS GCC is described (a) in c99status.html; (b) in
the manual (invoke.texi), where -std=c99 is documented (see
http://gcc.gnu.org/onlinedocs/gcc_2.html#SEC6 ).

> http://gcc.gnu.org/c99status.html
> giving status, but I was uncertain as to whether this reflects
> only the state of the development version of GCC, or a stable release,
> like 2.95.2 - no version information is given.

This relates to current GCC development.  When GCC 3.0 branches, I intend
to copy the current c99status.html to the release directory so details of
what's in 3.0 versus subsequent development stay available.

> - what are the plans to support C99 in GCC?  What version/timeframe is
> likely to offer this support?

Unless one of the companies providing GCC work gets paid to complete C99
support, it largely depends on volunteer effort and no timeframe is
available.  The only person listed in MAINTAINERS as responsible is

C front end/isoc9x      Gavin Romig-Koch        gavin@cygnus.com

but I don't know that he has much time for working on C99 support at
present.

-- 
Joseph S. Myers
jsm28@cam.ac.uk