Revert a change in the scope of macros imported from crates to fix a regression
Fixes#34212.
The regression was caused by #34032, which changed the scope of macros imported from extern crates to match the scope of macros imported from modules.
r? @nrc
Support nested `cfg_attr` attributes
Support arbitrarily deeply nested `cfg_attr` attributes (e.g. `#[cfg_attr(foo, cfg_attr(bar, baz))]`).
This makes configuration idempotent.
Currently, the nighties do not support any `cfg_attr` nesting. Stable and beta support just one level of `cfg_attr` nesting (expect for attributes on macro-expanded nodes, where no nesting is supported).
This is a [breaking-change]. For example, the following would break:
```rust
macro_rules! m { () => {
#[cfg_attr(all(), cfg_attr(all(), cfg(foo)))]
fn f() {}
} }
m!();
fn main() { f() } //~ ERROR unresolved name `f`
```
r? @nrc
Show types of all args when missing args
When there're missing arguments in a function call, present a list of
all the expected types:
```rust
fn main() {
t("");
}
fn t(a: &str, x: String) {}
```
```bash
% rustc file.rs
file.rs:3:5: 2:8 error: this function takes 2 parameters but 0
parameters were supplied [E0061]
file.rs:3 t();
^~~
file.rs:3:5: 2:8 help: run `rustc --explain E0061` to see a detailed explanation
file.rs:3:5: 2:8 note: the following parameter types were expected: &str, std::string::String
error: aborting due to previous error
```
Fixes#33649
When there're missing arguments in a function call, present a list of
all the expected types:
```rust
fn main() {
t("");
}
fn t(a: &str, x: String) {}
```
```bash
% rustc file.rs
file.rs:3:5: 2:8 error: this function takes 2 parameters but 0
parameters were supplied [E0061]
file.rs:3 t();
^~~
file.rs:3:5: 2:8 help: run `rustc --explain E0061` to see a detailed explanation
file.rs:3:5: 2:8 note: the following parameter types were expected: &str, std::string::String
error: aborting due to previous error
```
Fixes#33649
derive Hash (and not Copy) for ranges
Fixes#34170.
Also, `RangeInclusive` was `Copy` by mistake -- fix that, which is a [breaking-change] to that unstable type.
Visit statement and expression attributes in the AST visitor
Currently, these attributes are not visited, so they are not gated feature checked in the post expansion visitor. This only affects crates using `#![feature(stmt_expr_attributes)]`.
r? @nrc
Fix issue #34101
Fix issue #34101: do not track subcontent of type with dtor nor gather flags for untracked content.
(Includes a regression test, which needed to go into `compile-fail/`
due to weaknesses when combining `#[deny(warnings)]` with
`tcx.sess.span_warn(..)`)
The root of the problem is that a string literal pattern is essentially of
the form `&LITERAL`, in a single block, while match checking wants to
split that.
To fix that, I added a type field to the patterns in match checking,
which allows us to distinguish between a full and split pattern.
That file is ugly and needs to be cleaned. However, `trans::_match` calls
it, so I think we should delay the cleanup until we kill that.
Fixes#30240
Remove the old FOLLOW checking (aka `check_matcher_old`).
It was supposed to be removed at the next release cycle but is still in the tree since like 6 months.
Potential breaking change, since some cases (such as #25658) will change from a warning to an error. But the warning stating that it will be a hard error in the next release has been there for 6 months now.
I think it's safe to break this code. ^_^
(Includes a regression test, which needed to go into `compile-fail/`
due to weaknesses when combining `#[deny(warnings)]` with
`tcx.sess.span_warn(..)`)
(updated with review feedback from arielb1.)
rustc: add ReErased to be used by trait selection, MIR and trans.
`ReErased` replaces `ReStatic` (i.e. `'static`) for erasing regions.
Using a distinct lifetime helps prevent accidental mix-ups between the two.
It also allows cleaner type printing (see test changes), including in symbol names:
```rust
str..pattern..CharSearcher$LT$$u27$static$GT$::drop.30560::h840c2f2afc03bbea // before
str..pattern..CharSearcher::drop.30561::h6bd31d2af614377a // after
```
Not that we should be producing symbols this way, but it's still better.
Fix a regression in the configuration folder
This fixes#34028, a regression caused by #33706 in which unconfigured impl items generated by a macro in an impl item position are not removed.
r? @nrc
Projection cache and better warnings for #32330
This PR does three things:
- it lays the groundwork for the more precise subtyping rules discussed in #32330, but does not enable them;
- it issues warnings when the result of a leak-check or subtyping check relies on a late-bound region which will late become early-bound when #32330 is fixed;
- it introduces a cache for projection in the inference context.
I'm not 100% happy with the approach taken by the cache here, but it seems like a step in the right direction. It results in big wins on some test cases, but not as big as previous versions -- I think because it is caching the `Vec<Obligation>` (whereas before I just returned the normalized type with an empty vector). However, that change was needed to fix an ICE in @alexcrichton's future-rs module (I haven't fully tracked the cause of that ICE yet). Also, because trans/the collector use a fresh inference context for every call to `fulfill_obligation`, they don't profit nearly as much from this cache as they ought to.
Still, here are the results from the future-rs `retry.rs`:
```
06:26 <nmatsakis> time: 6.246; rss: 44MB item-bodies checking
06:26 <nmatsakis> time: 54.783; rss: 63MB translation item collection
06:26 <nmatsakis> time: 140.086; rss: 86MB translation
06:26 <nmatsakis> time: 0.361; rss: 46MB item-bodies checking
06:26 <nmatsakis> time: 5.299; rss: 63MB translation item collection
06:26 <nmatsakis> time: 12.140; rss: 86MB translation
```
~~Another example is the example from #31849. For that, I get 34s to run item-bodies without any cache. The version of the cache included here takes 2s to run item-bodies type-checking. An alternative version which doesn't track nested obligations takes 0.2s, but that version ICEs on @alexcrichton's future-rs (and may well be incorrect, I've not fully convinced myself of that). So, a definite win, but I think there's definitely room for further progress.~~
Pushed a modified version which improves performance of the case from #31849:
```
lunch-box. time rustc --stage0 ~/tmp/issue-31849.rs -Z no-trans
real 0m33.539s
user 0m32.932s
sys 0m0.570s
lunch-box. time rustc --stage2 ~/tmp/issue-31849.rs -Z no-trans
real 0m0.195s
user 0m0.154s
sys 0m0.042s
```
Some sort of cache is also needed for unblocking further work on lazy normalization, since that will lean even more heavily on the cache, and will also require cycle detection.
r? @arielb1
