Free `default()` forwarding to `Default::default()`
It feels a bit redundant to have to say `Default::default()` every time I need a new value of a type that has a `Default` instance.
Especially so, compared to Haskell, where the same functionality is called `def`.
Providing a free `default()` function that forwards to `Default::default()` seems to improve the situation.
The trait is still there, so if someone wants to be explicit and to say `Default::default()` - it still works, but if imported as `std::default::default;`, then the free function reduces typing and visual noise.
Cstring `from_raw` and `into_raw` safety precisions
Fixes#48525.
Fixes#68456.
This issue had two points:
- The one about `from_raw` has been addressed (I hope).
- The other one, about `into_raw`, has only been partially fixed.
About `into_raw`: the idea was to:
> steer users away from using the pattern of CString::{into_raw,from_raw} when interfacing with C APIs that may change the effective length of the string by writing interior NULs or erasing the final NUL
I tried making a `Vec<c_char>` like suggested but my current solution feels very unsafe and *hacky* to me (most notably the type cast), I included it here to make it available for discussion:
```rust
fn main() {
use std::os::raw::c_char;
let v = String::from("abc")
.bytes()
// From u8 to i8,
// I feel like it will be a problem for values of u8 > 255
.map(|c| c as c_char)
.collect::<Vec<_>>();
dbg!(v);
}
```
Add `-Z span-debug` to allow for easier debugging of proc macros
Currently, the `Debug` impl for `proc_macro::Span` just prints out
the byte range. This can make debugging proc macros (either as a crate
author or as a compiler developer) very frustrating, since neither the
actual filename nor the `SyntaxContext` is displayed.
This commit adds a perma-unstable flag `-Z span-debug`. When enabled,
the `Debug` impl for `proc_macro::Span` simply forwards directly to
`rustc_span::Span`. Once #72618 is merged, this will start displaying
actual line numbers.
While `Debug` impls are not subject to Rust's normal stability
guarnatees, we probably shouldn't expose any additional information on
stable until `#![feature(proc_macro_span)]` is stabilized. Otherwise,
we would be providing a 'backdoor' way to access information that's
supposed be behind unstable APIs.
Added the documentation for the 'use' keyword
This is a partial fix of #34601.
I heavily inspired myself from the Reference on the `use` keyword.
I checked the links when compiling the documentation, they should be ok.
I also added an example for the wildcard `*` in the case of types, because it's behaviour is not *import everything* like one might think at first.
Fix documentation example for gcov profiling
closes#72546
Improves the documentation for the unstable Rustflag `-Zprofile` by:
- stating that Incremental compilation must be turned off.
- Adding the other `RUSTFLAGS` that should/need to be turned on (taken from [grcov documentation](https://github.com/mozilla/grcov#example-how-to-generate-gcda-files-for-a-rust-project))
- Mentioning `RUSTC_WRAPPER` to prevent everything getting instrumented.
r? @steveklabnik
impl AsRef<[T]> for vec::IntoIter<T>
Adds `impl<T> AsRef<[T]> for vec::IntoIter<T>`. This mirrors the same trait impl for [`slice::Iter`](https://doc.rust-lang.org/nightly/std/slice/struct.Iter.html). Both types already offer `fn as_slice(&self) -> &[T]`, this just adds the trait impl for `vec::IntoIter`.
If/when `fn as_slice(&self) -> &[T]` stabilizes for `vec::Drain` and `slice::IterMut`, they should get `AsRef<[T]>` impls as well. As thus, tangentially related to #58957.
My ultimate goal here: being able to use `for<T, I: Iterator<Item=T> + AsRef<[T]>> I` to refer to `vec::IntoIter`, `vec::Drain`, and eventually `array::IntoIter`, as an approximation of the set of by-value iterators that can be "previewed" as by-ref iterators. (Actually expressing that as a trait requires GAT.)
Update annotate-snippets-rs to 0.8.0
#59346
I made major changes to this library. In the previous version we worked with owned while in the current one with borrowed.
I have adapted it without changing the behavior.
I have modified the coverage since the previous one did not return correctly the index of the character in the line.
Fix codegen tests for RISC-V
Some codegen tests didn't seem relevant (e.g. unsupported annotations).
The RISC-V abi tests were broken by LLVM 10, c872dcf fixes that (cc: @msizanoen1)
I'm not sure about skipping catch-unwind.rs and included that change here mostly as a request for comment - I can't tell if that's a bug.
run-make regression test for issue #70924.
Sometime after my PR #72767 (to fix issue #70924) landed, I realized that I *could* make a local regression test, thanks to `rustc --print sysroot`: I can make a fresh "copy" (really mostly symlinks) of the sysroot, and then modify it to recreate the terms of this bug.
I wasn't aware items _could_ be fake, so I think having a function
mentioning it could be helpful. Also, I'd need to make this change for
cross-crate intra-doc links anyway, so I figured it's better to make the
refactor separate.
Rollup of 5 pull requests
Successful merges:
- #72764 (Be more careful around ty::Error in generators)
- #72908 (rename FalseEdges -> FalseEdge)
- #72970 (Properly handle feature-gated lints)
- #72998 (Mention that some atomic operations may not be available on some platforms)
- #73063 (Elide type on liballoc vec)
Failed merges:
r? @ghost
Mention that some atomic operations may not be available on some platforms
fixes#54250
This simply adds a line saying the type/function/method may not be available on some platforms, depending on said platform capabilities.
I *think* I got them all.
Be more careful around ty::Error in generators
cc https://github.com/rust-lang/rust/issues/72685
(doesn't close it because it's missing a reproduction to use as a test case)
r? @estebank
When creating default values a trait method needs to be called with an
explicit trait name. `Default::default()` seems redundant. A free
function on the other hand, when imported directly, seems to be a better
API, as it is just `default()`. When implementing the trait, a method
is still required.
Update LLVM submodule to include lld NOLOAD fix
> Rust nightly 2020-05-22 and later ships lld with a regression related to linker scripts: NOLOAD sections incorrectly generate sections filled with 0s. This causes gdb and other elf loaders to write to reserved or otherwise invalid addresses (gdb also seems confused by the resulting ELF files and spits out a warning about the sections). This is particularly a problem for embedded rust projects that use lld by default and have affected linker scripts (cortex-m-rt based projects for instance).
https://github.com/rust-lang/llvm-project/pull/64
Note that this also pulls in llvm changes from #72937
