The commented invariant that an iterator is smaller than other iterator
was violated after next is called and two iterators are consumed at
different rates.
This makes the code a little faster, presumably because bounds checks
aren't needed on `nodes` accesses. It requires making `scratch` a
`RefCell`, which is not unreasonable.
This commit removes the custom index implementation of `NodeIndex`,
which probably predates `newtype_index!`.
As well as eliminating code, it improves the debugging experience,
because the custom implementation had the property of being incremented
by 1 (so it could use `NonZeroU32`), which was incredibly confusing if
you didn't expect it.
For some reason, I also had to remove an `unsafe` block marker from
`from_u32_unchecked()` that the compiler said was now unnecessary.
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`.
```
