we now detect inconsistent modes, binding names, and various other errors.
typeck/trans integration is mostly done.
borrowck not so much.
more tests needed.
API is (for now) mostly by value, there are options to use it by
reference if you like. Hash and equality functions must be pure
and by reference (forward looking to the day when something
like send_map becomes the standard map).
Previously, resolve was allowing impls, traits or classes that were
nested within a fn to refer to upvars, as well as referring to type
parameters bound by the fn. Fixing this required adding a new kind of
def: def_typaram_binder, which can refer to any of an impl, trait or
class that has bound ty params. resolve uses this to enforce that
methods can refer to their parent item's type parameters, but not to
outer items' type parameters; other stages ignore it. I also made
sure that impl, trait and class methods get checked inside a
MethodRibKind thing so as to forbid upvars, and changed the definition
of MethodRibKind so that its second argument is an optional node_id
(so that required trait method signatures can be checked with a
MethodRibKind as well).
New style is allow(foo), warn(foo), deny(foo) and forbid(foo),
mirrored by -A foo, -W foo, -D foo and -F foo on command line.
These replace -W no-foo, -W foo, -W err-foo, respectively.
Forbid is new, and means "deny, and you can't override it".
In order to avoid a confusing use of the tcache, I added an extra
node ID field to trait refs. Now trait refs have a "ref ID" (the one
that resolve3 resolves) and an "impl ID" (the one that you look up
in the tcache to get the self type).
Closes#2434
resolve3 wasn't checking this. Added test cases. Also added a helpful informational
message in the case where you have a variable binding that you probably think
refers to a variant that you forgot to import.
This is easier to do in resolve than in typeck because there's code in typeck
that assumes that each of the patterns binds the same number of variables.
