Re: [PATCH] add relation and block-level filtering to pg_waldump

On 21.03.22 05:55, Thomas Munro wrote:
> [04:30:50.630] pg_waldump.c:963:26: error: format ‘%u’ expects
> argument of type ‘unsigned int *’, but argument 3 has type ‘ForkNumber
> *’ [-Werror=format=]
> [04:30:50.630] 963 | if (sscanf(optarg, "%u",
> &config.filter_by_relation_forknum) != 1 ||
> [04:30:50.630] | ~^ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> [04:30:50.630] | | |
> [04:30:50.630] | | ForkNumber *
> [04:30:50.630] | unsigned int *
> 
> And now that this gets to the CompilerWarnings CI task, it looks like
> GCC doesn't like an enum as a scanf %u destination (I didn't see that
> warning locally when I compiled the above fixup because clearly Clang
> is cool with it...).  Probably needs a temporary unsigned int to
> sscanf into first.

That's because ForkNum is a signed type.  You will probably succeed if 
you use "%d" instead.