Re: [PATCH 16/21] __VA_OPT__: parsing

On Mon, Mar 16, 2026 at 07:04:10AM +0000, Al Viro wrote:
> +static struct token *parse_expansion(struct token *expansion, struct ident *name)
> +{
> +	int slots = macro_nargs + (macro_vararg < 0);
> +	struct arg_state args[slots] = {};
                         ^^^^^^^^^^^^^^^^

Hi Al,

gcc-11 and gcc-12 don't allow variable length arrays with an initializer.
The compile fails with:

pre-process.c: In function ‘parse_expansion’:
pre-process.c:1513:16: error: variable-sized object may not be initialized
 1513 |         struct arg_state args[slots] = {};
      |                ^~~~~~~~~
make: *** [Makefile:263: pre-process.o] Error 1
make: *** Waiting for unfinished jobs....

It works in gcc-13 and later.

regards,
dan carpenter