Disallow ._ in float literal.
This patch makes lexer stop parsing number literals before `._`, as well as before `.a`. Underscore itself is still allowed like in `4_000_000.000_000_`.
Fixes a half part of #41723. The other is `""_`.
rustc_resolve: don't deny outer type parameters in embedded constants.
This solves a problem noted at https://github.com/rust-lang/rust/issues/29646#issuecomment-300929548, where an associated const default in a trait couldn't refer to `Self` or type parameters, due to inaccuracies in lexical scoping.
I've also allowed "embedded expressions" (`[T; expr]`, `[x; expr]`, `typeof expr`) to refer to type parameters in scope. *However*, the typesystem still doesn't handle #34344.
Fully resolving that issue requires breaking cycles more aggressively (e.g. lazy evaluation), *even* in when the expression doesn't depend on type parameters, to type-check it at all, and then also type-level "constant projections" (in the vein of `{expr}` from const generics).
rustc: simpler ParameterEnvironment and free regions.
The commits describe the slow transformation but the highlights are:
* `ReEarlyBound` is considered free, with a scope based on the item that defined the lifetime parameter, and the root body of the `RegionMaps` in use, removing the need for `free_substs`
* `liberate_late_bound_regions` and `implicit_region_bound` moved to typeck
* `CodeExtent` not interned at all now - ideally it would be 2 `u32` but it's small anyway
Future work building up on this could include:
* `ParameterEnvironment` becoming just the result of `predicates_of`
* interning makes my "parent chain" scheme unnecessary
* `implicit_region_bound` could be retrieved from `RegionMaps`
* renaming `CodeExtent` to `Scope`
* generalizing "call site" to "use site" or something better to include constants
* renaming `RegionMaps` to `ScopeTree` and its API to talk about "parents" explicitly
remove the #[inline] attribute from drop_in_place
Apparently LLVM has exponential code growth while inlining landing pads
if that attribute is present.
Fixes#41696.
beta-nominating because regression.
r? @eddyb
rustc: Stabilize `-C target-feature=+crt-static`
This commit stabilizes the `crt-static` feature accepted by the compiler. Note
that this does not stabilize the `#[cfg]` attribute for `crt-static` as
that's going to be covered by #29717. This only stabilizes a few small pieces:
* The `crt-static` feature as accepted by the `-C target-feature` flag, and its
connection with the platform-specific definition of `crt-static`.
* The semantics of `--print cfg` printing out activated `crt-static` feature, if
available.
This should be enough to get the benefits of `crt-static` on stable Rust with
MSVC and with musl, but sidsteps the issue of stabilizing #29717 first.
Closes#37406
enforce WF conditions after generalizing
Add a `WF(T')` obligation after generalizing `T` to `T'`, if `T'` contains an unconstrained type variable in a bivariant context.
Fixes#41677.
Beta nominating -- regression.
r? @arielb1
Fixes#41849. Problem was that evaluating the constant expression
required evaluating a trait, which would equate types, which would
request variance information, which it would then discard. However,
computing the variance information would require determining the type of
a field, which would evaluate the constant expression.
(This problem will potentially arise *later* as we move to more sophisticated
constants, however, where we need to check subtyping. We can tackle that
when we come to it.)
Add `eprint!` and `eprintln!` macros to the prelude.
These are exactly the same as `print!` and `println!` except that they write to stderr instead of stdout. Issues #39228 and #40528; previous PR #39229; accepted RFC rust-lang/rfcs#1869; proposed revision to The Book rust-lang/book#615.
I have _not_ revised this any since the original submission; I will do that later this week. I wanted to get this PR in place since it's been quite a while since the RFC was merged.
Known outstanding review comments:
* [x] @steveklabnik requested a new chapter for the unstable version of The Book -- please see if the proposed revisions to the second edition cover it.
* [x] @nodakai asked if it were possible to merge the internal methods `_print` and `_eprint` - not completely, since they both refer to different internal globals which we don't want to expose, but I will see if some duplication can be factored out.
Please let me know if I missed anything.
incr.comp.: Hash more pieces of crate metadata to detect changes there.
This PR adds incr. comp. hashes for non-`Entry` pieces of data in crate metadata.
The first part of it I like: `EntryBuilder` is refactored into the more generally applicable `IsolatedEncoder` which provides means of encoding something into metadata while also feeding the encoded data into an incr. comp. hash. We already did this for `Entry`, now we are doing it for various other pieces of data too, like the set of exported symbols and so on. The hashes generated there are persisted together with the per-`Entry` hashes and are also used for dep-graph dirtying the same way.
The second part of the PR I'm not entirely happy with: In order to make sure that we don't forget registering a read to the new `DepNodes` introduced here, I added the `Tracked<T>` struct. This struct wraps a value and requires a `DepNode` when accessing the wrapped value. This makes it harder to overlook adding read edges in the right places and works just fine.
However, crate metadata is already used in places where there is no `tcx` yet or even in places where no `cnum` has been assigned -- this makes it harder to apply this feature consistently or implement it ergonomically. The result is not too bad but there's a bit more code churn and a bit more opportunity to get something wrong than I would have liked. On the other hand, wrapping things in `Tracked<T>` already has revealed some bugs, so there's definitely some value in it.
This is still a work in progress:
- [x] I need to write some test cases.
- [x] Accessing the CodeMap should really be dependency tracked too, especially with the new path-remapping feature.
cc @nikomatsakis
dump-mir was causing cycles by invoking item-path-str at bad times
Workaround for now, but probably a better fix is to opt **in** to using the types for impls (if we do that at all; maybe filename/line is better).
Fixes#41697
Fixed argument inference for closures when coercing into 'fn'
This fixes https://github.com/rust-lang/rust/issues/41755. The tests `compile-fail/closure-no-fn.rs` and `compile-fail/issue-40000.rs` were modified. A new test `run-pass/closure_to_fn_coercion-expected-types.rs` was added
r? @nikomatsakis
Implement the illegal_floating_point_literal_pattern compat lint
Adds a future-compatibility lint for the [breaking-change] introduced by issue #41620 . cc issue #41255 .
rustc: treat const bodies like fn bodies in middle::region.
Allows `T::ASSOC_CONST` to be used without a `T: 'static` bound.
cc @rust-lang/compiler @rust-lang/lang
Point at fields that make the type recursive
On recursive types of infinite size, point at all the fields that make
the type recursive.
```rust
struct Foo {
bar: Bar,
}
struct Bar {
foo: Foo,
}
```
outputs
```
error[E0072]: recursive type `Foo` has infinite size
--> file.rs:1:1
1 | struct Foo {
| ^^^^^^^^^^ recursive type has infinite size
2 | bar: Bar,
| -------- recursive here
|
= help: insert indirection (e.g., a `Box`, `Rc`, or `&`) at some point to make `Foo` representable
error[E0072]: recursive type `Bar` has infinite size
--> file.rs:5:1
|
5 | struct Bar {
| ^^^^^^^^^^ recursive type has infinite size
6 | foo: Foo,
| -------- recursive here
|
= help: insert indirection (e.g., a `Box`, `Rc`, or `&`) at some point to make `Bar` representable
```
Allow # to appear in rustdoc code output.
"##" at the start of a trimmed rustdoc line is now cut to "#" and then
shown. If the user wanted to show "##", they can type "###".
I'm somewhat concerned about the potential implications for users, since this does make a potentially backwards-incompatible change. Previously, `##` had no special handling, and now we do change it. However, I'm not really sure what we can do here to improve this, and I can't think of any cases where `##` would likely be correct in a code block, though of course I could be wrong.
Fixes#41783.
