make `ConstEvaluatable` more strict
relevant zulip discussion: https://rust-lang.zulipchat.com/#narrow/stream/146212-t-compiler.2Fconst-eval/topic/.60ConstEvaluatable.60.20generic.20functions/near/204125452
Let's see how much this impacts. Depending on how this goes this should probably be a future compat warning.
Short explanation: we currently forbid anonymous constants which depend on generic types, e.g. `[0; std::mem::size_of::<T>]` currently errors.
We previously checked this by evaluating the constant and returned an error if that failed. This however allows things like
```rust
const fn foo<T>() -> usize {
if std::mem::size_of::<*mut T>() < 8 { // size of *mut T does not depend on T
std::mem::size_of::<T>()
} else {
8
}
}
fn test<T>() {
let _ = [0; foo::<T>()];
}
```
which is a backwards compatibility hazard. This also has worrying interactions with mir optimizations (https://github.com/rust-lang/rust/pull/74491#issuecomment-661890421) and intrinsics (#74538).
r? `@oli-obk` `@eddyb`
This avoids overlapping a reference covering the data field,
which may be changed due in concurrent conditions. This fully
fixed the UB mainfested with `new_cyclic`.
BTreeMap mutable iterators should not take any reference to visited nodes during iteration
Fixes#73915, overlapping mutable references during BTreeMap iteration
r? `@RalfJung`
Make rustdoc output deterministic for UI tests
Closes https://github.com/rust-lang/rust/issues/76442 (hopefully, since it's non-deterministic I don't have a way to test).
r? `@Mark-Simulacrum`
cc `@GuillaumeGomez`
rustdoc: Fix font CSS for crate lists
I had put it in the wrong file in #76126. This should fix it now. Thank
you to `@ollie27` for pointing this out!
---
`@rustbot` modify labels: T-rustdoc C-bug
`write` is ambiguous because there's also a macro called `write`.
Also removed unnecessary and potentially confusing link to a function in
its own docs.
Many developers use a dark theme with editors and IDEs, but this
typically doesn't extend to graphviz output.
When I bring up a MIR graphviz document, the white background is
strikingly bright. This new option changes the colors used for graphviz
output to work better in dark-themed UIs.
Update cargo
8 commits in 126907a7cfccbe93778530e6a6bbaa3adb6c515c..875e0123259b0b6299903fe4aea0a12ecde9324f
2020-08-31 20:42:11 +0000 to 2020-09-08 20:17:21 +0000
- Lowercase and remove periods in error messages for consistency (rust-lang/cargo#8655)
- Allow running build-man.sh from any directory (rust-lang/cargo#8682)
- docs: add details for cargo check pass where cargo build fail (rust-lang/cargo#8677)
- Fix nightly exported_priv_warning test. (rust-lang/cargo#8678)
- fix mdbook test with ```ignore/text/sh/console (rust-lang/cargo#8674)
- End CACHEDIR.TAG with newline (rust-lang/cargo#8672)
- Fixed the fossil repo initialization actually run commands (rust-lang/cargo#8671)
- Remove asciidoc attribute in cargo-metadata man page. (rust-lang/cargo#8670)
Add help note to unconstrained const parameter
Resolves#68366, since it is currently intended behaviour.
If demonstrating `T -> U` is injective, there should be an additional word that it is not **yet** supported.
r? @lcnr
Fix HashMap visualizers in Visual Studio (Code)
CDB (as used in unit tests) doesn't care that we're using static_cast between unrelated types (`u8*` to `tuple<$T1, $T2>*`).
Visual Studio & Visual Studio Code care. These should've been reinterpret_cast or C casts.
Credit to @petrochenkov per https://github.com/rust-lang/rust/issues/76352 for helping catch this.
### Testing
```cmd
x.py test --stage 1 src/tools/tidy
x.py test --stage 1 --build x86_64-pc-windows-msvc src\test\debuginfo
```
remove public visibility previously needed for rustfmt
`submod_path_from_attr` in rustc_expand::module was previously public because it was also consumed by rustfmt. However, we've done a bit of refactoring in rustfmt and no longer need to use this function.
This changes the visibility to the parent mod as was originally going to be done before the rustfmt dependency was realized (c189565edc (diff-cd1b379893bae95f7991d5a3f3c6d337R201))
