Enable LVI hardening for x86_64-fortanix-unknown-sgx
This implements mitigations for the Load Value Injection vulnerability (CVE-2020-0551) for the `x86_64-fortanix-unknown-sgx` target by enabling new LLVM passes. More information about LVI and mitigations may be found at https://software.intel.com/security-software-guidance/insights/deep-dive-load-value-injection.
This PR unconditionally enables the mitigations for `x86_64-fortanix-unknown-sgx` since there is no available hardware that doesn't require the mitigations. This may be reconsidered in the future.
* [x] This depends on https://github.com/rust-lang/compiler-builtins/pull/359/
let_and_return: avoid "does not live long enough" errors
EDIT: Add #3324 to the list of fixes
<details>
<summary>Description of old impl</summary>
<br>
Avoid suggesting turning the RHS expression of the last statement into the block tail expression if a temporary borrows from a local that would be destroyed before.
This is my first incursion into MIR so there's probably room for improvement!
</details>
Avoid linting if the return type of some method or function called in the last statement has a lifetime parameter.
changelog: Fix false positive in [`let_and_return`]
Fixes#3792Fixes#3324
New lint: `unnested_or_patterns`
changelog: Adds a lint `unnested_or_patterns`, suggesting `Some(0 | 2)` as opposed to `Some(0) | Some(2)`. The lint only fires on compilers capable of using `#![feature(or_patterns)]`.
- The lint is primarily encoded as a pure algorithm which to unnest or-patterns in an `ast::Pat` (`fn unnest_or_patterns`) through a `MutVisitor`. After that is done, and assuming that any change was detected, then `pprust::pat_to_string` is used to simply convert the transformed pattern into a suggestion.
- The PR introduces a module `utils::ast_utils` with a bunch of functions for spanless & nodeless equality comparisons of ASTs.
cc https://github.com/rust-lang/rust/issues/54883
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
