On Tue, 15 May 2018 19:37:02 +0200 Markus Armbruster <arm...@redhat.com> wrote:
> Eric Blake <ebl...@redhat.com> writes: > > > On 05/15/2018 10:26 AM, Andrew Jones wrote: > >> On Tue, May 15, 2018 at 04:48:33PM +0200, Igor Mammedov wrote: > >>> When using following CLI: > >>> -numa dist,src=128,dst=1,val=20 > >>> user gets a rather confusing error message: > >>> "Invalid node 128, max possible could be 128" > >>> > >>> Where 128 is number of nodes that QEMU supports (MAX_NODES), > >>> while src/dst is an index up to that limit, so it should be > >>> MAX_NODES - 1 in error message. > >>> Make error message to explicitly state valid range for node > >>> index to be more clear. > >>> > >>> Signed-off-by: Igor Mammedov <imamm...@redhat.com> > >>> Reviewed-by: Andrew Jones <drjo...@redhat.com> > >>> --- > > > >>> if (src >= MAX_NODES || dst >= MAX_NODES) { > >>> error_setg(errp, > >>> - "Invalid node %d, max possible could be %d", > >>> - MAX(src, dst), MAX_NODES); > >>> + "Invalid node %d, The valid node range is [0 - %d]", > >> ^ should be a '.' > >> > >> And maybe need a '.' at the end of the second sentence too, as it's not > >> an error phrase, but a real sentence. > >> > >>> + MAX(src, dst), MAX_NODES - 1); > >>> return; > >>> } > > > > Actually, error_setg() is documented as taking a single phrase (no '.' > > included), and that if you need a second sentence, it's better to use > > error_append_hint(). well, using append_hint makes it less readable, before using it we get following error: $ qemu-system-x86_64 -numa dist,src=128,dst=1,val=20 qemu-system-x86_64: -numa dist,src=128,dst=1,val=20: Invalid node 128, The valid node range is [0 - 127] $ after using it we get: $ qemu-system-x86_64 -numa dist,src=128,dst=1,val=20 qemu-system-x86_64: -numa dist,src=128,dst=1,val=20: Invalid node value 128 The valid node range is [0 - 127]$ i.e. an extra newline in the middle of error message and looses automatic newline at the end so the shell prompt continues error message > Correct. Providing help on valid values is exactly what > error_append_hint() is for. > > > Maybe Markus has an opinion on the best way to > > word this error message. > > Yes: "Parameter 'src' expects an integer between 0 and 127" > > Referring to an erroneous key=value by value is not nice. What if the > value occurs in multiple places, and is valid in at least one? key is > there, it's unique[*], so use it. > > > [*] Except in the few places that use repeated keys to form lists. Ugh.