Re: [PATCH 01/11] perf tools: Introduce struct perf_maps_opts

[Arnaldo Carvalho de Melo <acme@ghostprotocols.net>]

Em Mon, Feb 13, 2012 at 11:50:29AM -0700, David Ahern escreveu:
> The cleanup might make my multiple tid/pid patch easier: e.g.,
> 
> struct perf_target{
> 	...
> 	char errmsg[128];
> };
> 
> Then if the tid/pid string parsing fails in perf_evlist__create_maps and
> friends the errmsg can be put into the buffer for the callers to get a
> more useful message to the user as to what happened.
> 
> Today's perf if you give it an invalid pid, scandir fails and the
> command spits out the usage statement. Which is completely confusing --
> ie., not clear that the command failed b/c the pid does not exist.

Humm, ok, but then I think we should have an enum + a strerror(3)
equivalent, i.e.:

	enum perf_target_error perf_evlist__create_maps(...);

	int perf_target__strerror(struct perf_target *target, int errnum,
				  char *buf, size_t buflen);

Please see 'man strerror_r", and make it work like the POSIX compliant
variant.

Ok, so it may be better to first process Kim's patches and then you
rework yours?

- Arnaldo