In particular, type annotations given by the user must hold at all
points in the program. This doesn't affect current analysis but
will affect fact generation later.
rustc: return iterators from Terminator(Kind)::successors(_mut).
Minor cleanup (and potentially speedup) prompted by @nnethercote's `SmallVec` experiments.
This PR assumes `.count()` and `.nth(i)` on `iter::Chain<option::IntoIter, slice::Iter(Mut)>` are `O(1)`, but otherwise all of the uses appear to immediately iterate through the successors.
r? @nikomatsakis
Partial future-proofing for Box<T, A>
In some ways, this is similar to @eddyb's PR #47043 that went stale, but doesn't cover everything. Notably, this still leaves Box internalized as a pointer in places, so practically speaking, only ZSTs can be practically added to the Box type with the changes here (the compiler ICEs otherwise).
The Box type is not changed here, that's left for the future because I want to test that further first, but this puts things in place in a way that hopefully will make things easier.
Because box_free is now passed a pointer instead of a Box, we can stop
relying on TypeChecked::check_box_free_inputs, because
TypeChecker::check_call_inputs should be enough, like for all other
function calls.
It seems it was not actually reached anyways in cases where it would
have made a difference. (issue #50071)
prep work for using timely dataflow with NLL
Two major changes:
**Two-phase borrows are overhauled.** We no longer have two bits per borrow. Instead, we track -- for each borrow -- an (optional) "activation point". Then, for each point P where the borrow is in scope, we check where P falls relative to the activation point. If P is between the reservation point and the activation point, then this is the "reservation" phase of the borrow, else the borrow is considered active. This is simpler and means that the dataflow doesn't have to care about 2-phase at all, at last not yet.
**We no longer support using the MIR borrow checker without NLL.** It is going to be increasingly untenable to support lexical mode as we go forward, I think, and also of increasingly little value. This also exposed a few bugs in NLL mode due to increased testing.
r? @pnkfelix
cc @bobtwinkles
Move Range*::contains to a single default impl on RangeBounds
Per the ongoing discussion in #32311.
This is my first PR to Rust (woo!), so I don't know if this requires an amendment to the original range_contains RFC, or not, or if we can just do a psuedo-RFC here. While this may no longer follow the explicit decision made in that RFC, I believe this better follows its spirit by adding the new contains method to all Ranges. It also allows users to be generic over all ranges and use this method without writing it themselves (my personal desired use case).
This also somewhat answers the unanswered question about Wrapping ranges in the above issue by instead just punting it to the question of what those types should return for start() & end(), or if they should implement RangeArgument at all. Those types could also implement their own contains method without implementing this trait, in which case the question remains the same.
This does add a new contains method to types that already implemented RangeArgument but not contains. These types are RangeFull, (Bound<T>, Bound<T>), (Bound<&'a T>, Bound<&'a T>). No tests have been added for these types yet. No inherent method has been added either.
r? @alexcrichton
optimize NLL constraint propagation a little
Removes a bone-headed hot spot in NLL constant propagation; we were re-allocating the stack vector and hashmap as we repeated the DFS. This change shares those resources across each call.
It also modifies the constraint list to be a linked list; arguably I should revert that, though, as this didn't turn out to be a perf hit and perhaps the old code was clearer? (Still, the new style appeals to me.)
r? @pnkfelix
This commit modifies the UserAssertTy statement to take a canonicalized
type rather than a regular type so that we can handle the case where the
user provided type contains a inference variable.
