std: Update compiler-rt for more ABI fixes
This update of compiler-rt includes rust-lang/compiler-rt#26 which provides a
targeted fix to the powisf2 intrinsics to keep #37559 fixed but also address
the new issue of #37630. I've also [written up my thoughts][1] on why it appears
that this is the correct fix for now (hoepfully at least).
Closes#37630
[1]: https://github.com/rust-lang/compiler-rt/pull/26#issuecomment-259751998
This teaches `format_args!` how to interpret format printf- and
shell-style format directives. This is used in cases where there are
unused formatting arguments, and the reason for that *might* be because
the programmer is trying to use the wrong kind of formatting string.
This was prompted by an issue encountered by simulacrum on the #rust IRC
channel. In short: although `println!` told them that they weren't using
all of the conversion arguments, the problem was in using printf-syle
directives rather than ones `println!` would undertand.
Where possible, `format_args!` will tell the programmer what they should
use instead. For example, it will suggest replacing `%05d` with `{:0>5}`,
or `%2$.*3$s` with `{1:.3$}`. Even if it cannot suggest a replacement,
it will explicitly note that Rust does not support that style of directive,
and direct the user to the `std::fmt` documentation.
While the commit message on this one sounds terrible, it's really not so
bad. The issue is that our test runner _expects_ a `fn main() {}` in
code blocks that it'll test, but this code really shouldn't have them.
If it did, then clicking the "play" link in the docs would result in
play.rust-lang.org not treating this code as a test example to be run.
Don't provide hint to add lifetime on impl items that implement a trait.
```rust
use std::str::FromStr;
pub struct Foo<'a> {
field: &'a str,
}
impl<'a> FromStr for Foo<'a> {
type Err = ();
fn from_str(path: &str) -> Result<Self, ()> {
Ok(Foo { field: path })
}
}
```
would give the following hint:
```nocode
help: consider using an explicit lifetime parameter as shown: fn from_str(path: &'a str) -> Result<Self, ()>
--> <anon>:9:5
|
9 | fn from_str(path: &str) -> Result<Self, ()> {
| ^
```
which is never correct, since then there will be a lifetime mismatch
between the impl and the trait.
Remove this hint for impl items that implement a trait.
Discussed in #37546 the libs team reached the conclusion that a default zero
duration seems like a reasonable implementation of the `Default` trait.
Closes#37546
proc_macro_plugin: Wrap nonexistent filename in <>
I'm not sure how big of an issue this can become in practice, but `FileMap`s made from something that's not a file are supposed to wrap the file name in `<>`.
For an example fix, see kevinmehall/rust-peg@332fd4dbae. There, it caused cargo to always recompile a crate using rust-peg, even when nothing was changed, because cargo sees that the dummy file doesn't exist.
Fix regression involving custom derives on items with `$crate`
The regression was introduced in #37213.
I believe we cannot make the improvements from #37213 work with the current custom derive setup (c.f. https://github.com/rust-lang/rust/issues/37637#issuecomment-258959145) -- we'll have to wait for `TokenStream`'s API to improve.
Fixes#37637.
r? @nrc
This update of compiler-rt includes rust-lang/compiler-rt#26 which provides a
targeted fix to the powisf2 intrinsics to keep #37559 fixed but also address
the new issue of #37630. I've also [written up my thoughts][1] on why it appears
that this is the correct fix for now (hoepfully at least).
Closes#37630
[1]: https://github.com/rust-lang/compiler-rt/pull/26#issuecomment-259751998
Without these changes, play.rust-lang.org (as of today) would wrap
our examples in `fn main() {}`. This prevents the user from being able
to easily run the tests.
macros: improve reexports
This PR
- avoids building multiple module graphs for a crate that is referenced by multiple `extern crate` items,
- registers `#[no_link] extern crate`s to avoid loading the same crate metadata twice,
- stability checks `#[no_link] extern crate`s,
- [breaking-chage]: `#[no_link] #[macro_use] extern crate syntax;` is allowed on stable today
- fixes `$crate` in `#[macro_reexport]`ed macros,
- [breaking-change] for `#[feature(macro_reexport)]` (technically)
- allows selective macro importing (i.e. `#[macro_use(foo, bar)]`) from custom derive crates, and
- refactors the crate metadata to support re-exported macros in arbitrary modules (not yet needed).
r? @nrc
This allows the initial build of src/bootstrap itself to use a local
cargo taken from `configure --local-rust-root`. It was already finding
rustc this way, but was always downloading cargo since it didn't know
where to find it.
It now matches the same logic that `config.rs` will use for stage0,
where both rustc and cargo are taken from `CFG_LOCAL_RUST_ROOT`.
