Rollup of 3 pull requests
Successful merges:
- #63872 (Document platform-specific behavior of the iterator returned by std::fs::read_dir)
- #64250 (save-analysis: Nest typeck tables when processing functions/methods)
- #64472 (Don't mark expression with attributes as not needing parentheses)
Failed merges:
r? @ghost
Don't mark expression with attributes as not needing parentheses
This is not perfectly correct as `#[attr] (5)` will still not lint, but it does seem good enough, in particular as the parentheses in that case are not unambiguously incorrect; I might personally prefer to see them for clarity.
Fixes https://github.com/rust-lang/rust/issues/43279.
save-analysis: Nest typeck tables when processing functions/methods
Fixes an issue where we did not nest tables correctly when resolving
associated types in formal argument/return type positions.
This was the minimized reproduction case that I tested the fix on:
```rust
pub trait Trait {
type Assoc;
}
pub struct A;
pub fn func() {
fn _inner1<U: Trait>(_: U::Assoc) {}
fn _inner2<U: Trait>() -> U::Assoc { unimplemented!() }
impl A {
fn _inner1<U: Trait>(self, _: U::Assoc) {}
fn _inner2<U: Trait>(self) -> U::Assoc { unimplemented!() }
}
}
```
using `debug_assertions`-enabled rustc and by additionally passing `-Zsave-analysis`.
Unfortunately the original assertion fired is a *debug* one and from what I can tell we don't run the tests with these on, so I'm not adding a test here. If I missed it and there is a way to run tests with these on, I'd love to add a test case for this.
Closes#63663Closes#50328Closes#43982
Cleanup handling of hygiene for built-in macros
This makes most identifiers generated by built-in macros use def-site hygiene, not only the ones that previously used gensyms.
* `ExtCtxt::ident_of` now takes a `Span` and is preferred to `Ident::{from_str, from_str_and_span}`
* Remove `Span::with_legacy_ctxt`
* `assert` now uses call-site hygiene because it needs to resolve `panic` unhygienically.
* `concat_idents` now uses call-site hygiene because it wouldn't be very useful with def-site hygiene.
* everything else is moved to def-site hygiene
r? @petrochenkov
Warn on no_start, crate_id attribute use
These attributes are now deprecated; they don't have any use anymore.
`no_start` stopped being applicable in 3ee916e50b as part of #18967. Ideally we would've removed it pre-1.0, but since that didn't happen let's at least mark it deprecated.
`crate_id` was renamed to `crate_name` in 50ee1ec1b4 as part of #15319. Ideally we would've followed that up with a removal of crate_id itself as well, but that didn't happen; this PR finally marks it as deprecated at least.
Fixes https://github.com/rust-lang/rust/issues/43142 and resolves https://github.com/rust-lang/rust/issues/43144.
def_collector: Do not ICE on attributes on unnamed fields
The primary issue here is that the expansion infra needs to visit a field in isolation, and fields don't know their own indices during expansion, so they have to be kept in some other place (e.g. `struct Definitions`).
Fixes https://github.com/rust-lang/rust/issues/64385
Use `panic::set_hook` to print the ICE message
This allows custom frontends and backends to override the hook with their own, for example to point people to a different issue tracker.
ICE messages are printed in a slightly different order now. Nightly prints:
```
thread 'rustc' panicked at 'called `Option::unwrap()` on a `None` value', src/libcore/option.rs:347:21
note: Run with `RUST_BACKTRACE=1` environment variable to display a backtrace.
error: aborting due to 2 previous errors
Some errors have detailed explanations: E0277, E0658.
For more information about an error, try `rustc --explain E0277`.
error: internal compiler error: unexpected panic
note: the compiler unexpectedly panicked. this is a bug.
note: we would appreciate a bug report: https://github.com/rust-lang/rust/blob/master/CONTRIBUTING.md#bug-reports
note: rustc 1.36.0-nightly (08bfe1612 2019-05-02) running on x86_64-unknown-linux-gnu
```
After this PR, rustc prints:
```
thread 'rustc' panicked at 'called `Option::unwrap()` on a `None` value', src/libcore/option.rs:347:21
note: Run with `RUST_BACKTRACE=1` environment variable to display a backtrace.
error: internal compiler error: unexpected panic
note: the compiler unexpectedly panicked. this is a bug.
note: we would appreciate a bug report: https://github.com/rust-lang/rust/blob/master/CONTRIBUTING.md#bug-reports
note: rustc 1.36.0-dev running on x86_64-unknown-linux-gnu
error: aborting due to 2 previous errors
Some errors have detailed explanations: E0277, E0658.
For more information about an error, try `rustc --explain E0277`.
```
This is not perfectly correct as `#[attr] (5)` will still not lint, but
it does seem good enough, in particular as the parentheses in that case
are not unambiguously incorrect.
feature_gate: Remove dead code from attribute checking
https://github.com/rust-lang/rust/pull/63468 is merged, so all attributes go through name resolution now, so we can remove code that previously performed some checks for attributes not going through resolution.
Provide a span if main function is not present in crate
Unfortunately, the diagnostic machinery does not cope well with an empty
span which can happen if the crate is empty, in which case we merely set
a spanless note.
Tests are already updated for this change, so a dedicated test is not added.
Resolves#36561.
Unfortunately, the diagnotic machinery does not cope well with an empty
span which can happen if the crate is empty, in which case we merely set
a spanless note.
codegen: use "_N" (like for other locals) instead of "argN", for argument names.
Based on #64408 (second commit is new), fixing something I mentioned in #64408 (which turned to be an immediate blocker for unifying relevant codepaths).
Closes#64408 (by containing it).
r? @rkruppe
check_match: refactor + improve non-exhaustive diagnostics for default binding modes
Refactor `check_match` a bit with more code-reuse and improve the diagnostics for a non-exhaustive pattern match by peeling off any references from the scrutinee type so that the "defined here" label is added in more cases. For example:
```rust
error[E0004]: non-exhaustive patterns: `&mut &B` not covered
--> foo.rs:4:11
|
1 | enum E { A, B }
| ---------------
| | |
| | not covered
| `E` defined here
...
4 | match x {
| ^ pattern `&mut &B` not covered
|
= help: ensure that all possible cases are being handled, possibly by adding wildcards or more match arms
```
Moreover, wrt. "defined here", we give irrefutable pattern matching (i.e. in `let`, `for`, and `fn` parameters) a more consistent treatment in line with `match`.
r? @estebank
std: Add a `backtrace` module
This commit adds a `backtrace` module to the standard library, as
designed in [RFC 2504]. The `Backtrace` type is intentionally very
conservative, effectively only allowing capturing it and printing it.
Additionally this commit also adds a `backtrace` method to the `Error`
trait which defaults to returning `None`, as specified in [RFC 2504].
More information about the design here can be found in [RFC 2504] and in
the [tracking issue].
Implementation-wise this is all based on the `backtrace` crate and very
closely mirrors the `backtrace::Backtrace` type on crates.io. Otherwise
it's pretty standard in how it handles everything internally.
[RFC 2504]: https://github.com/rust-lang/rfcs/blob/master/text/2504-fix-error.md
[tracking issue]: https://github.com/rust-lang/rust/issues/53487
cc #53487
