On 10/20/2012 11:16 AM, Zac Medico wrote:
On 10/20/2012 03:52 AM, Gregory M. Turner wrote:
EAPI[0-3] conventions encourage the habit of writing ebuild code like
invoke_fn || ... # handle error, probably by die()ing but maybe not
But eclasses that auto-die violate this expectation and create a
situation where ebuild authors must be mindful of whether a particular
function is a helper-function or an eclass utility function to correctly
anticipate whether auto-death will occur.
should we really write new eclass code to behave this way as well?
Yeah, I think we should. If the eclass function is doing something that
might result in an undesirable die, then it can try to avoid the die by
first doing a sanity check. For example, it can check that a given file
path exists before passing it to the helper, and skip calling the helper
if the file path doesn't exist.
That seems reasonable -- in practice, I don't find myself needing to
invoke helpers very much at all in eclasses, nor does it seem too
terribly frequent in the existing eclasses (dodir is pretty common, but
unlikely to fail unless something is seriously wrong anyhow).
Would it be feasible to lift the >=EAPI4 restriction on nonfatal()? I
guess the problem would be that old portage's wouldn't have it.
Anyhow, given that eclasses can probably avoid auto-die() if they need
to, this leaves the issue of nonfatal allowing die to return to
callers... is there really any reason that die() needs to work this way?
If helpers always used __helpers_die() instead of die(), then couldn't
die() be changed to ignore PORTAGE_NONFATAL?
It almost seems like the portage code was designed for nonfatal only to
apply to helper invocations, and then the change to die() was added as
an afterthought, to support the broader range of usages suggested
(rather vaguely, I'd say) by the language in the PMS, ... yet somehow,
the PMS ends up strongly suggesting -- I think most people would read
the language as an explicit specification -- that ebuilds can rely on
die() to terminate regardless of any usage of nonfatal.
-gmt
-gmt
