Implement synchronization scheme for incr. comp. directory
This PR implements a copy-on-write-based synchronization scheme for the incremental compilation cache directory. For technical details, see the documentation at the beginning of `rustc_incremental/persist/fs.rs`.
The PR contains unit tests for some functions but for testing whether the scheme properly handles races, a more elaborate test setup would be needed. It would probably involve a small tool that allows to manipulate the incremental compilation directory in a controlled way and then letting a compiler instance run against directories in different states. I don't know if it's worth the trouble of adding another test category to `compiletest`, but I'd be happy to do so.
Fixes#32754Fixes#34957
Bonus format for E0194
Bonus fix for #35280. Part of #35233. Fixes#36057. Adding expanded notes/context for what trait a parameter shadows as part of E0194 error messages.
Errors for E0194 now look like this:
```
$> ./build/x86_64-apple-darwin/stage1/bin/rustc src/test/compile-fail/E0194.rs
error[E0194]: type parameter `T` shadows another type parameter of the same name
--> src/test/compile-fail/E0194.rs:13:26
|
11 | trait Foo<T> { //~ NOTE first `T` declared here
| - first `T` declared here
12 | fn do_something(&self) -> T;
13 | fn do_something_else<T: Clone>(&self, bar: T);
| ^ shadows another type parameter
error: aborting due to previous error
```
r? @jonathandturner
Add test for #14875
You can check this out in the playground https://is.gd/oVKC2T . It will fail on stable, but pass on nightly as @nagisa suggested on the issue.
Fixes#14875
add evocative examples for `BitOr` and `BitXor`
These are exactly equivalent to PR #35809, with one caveat: I do not believe there is a non-bitwise binary XOR operator in Rust, so here it's expressed as `(a || b) && !(a && b)`.
Alternative decompositions are `(a && !b) || (!a && b)` and `(a || b) && (!a || !b)`. Let me know if you think one of those would be clearer.
r? @GuillaumeGomez
accumulate vector and assert for RangeFrom and RangeInclusive examples
PR #35695 for `Range` was merged, so it seems that this side-effect-free style is preferred for Range* examples. This PR performs the same translation for `RangeFrom` and `RangeInclusive`. It also removes what looks to be an erroneously commented line for `#![feature(step_by)]`, and an unnecessary primitive-type annotation in `0u8..`.
gdb: Fix pretty-printing special-cased Rust types
gdb trunk now reports fully qualified type names, just like lldb. Move lldb code for extracting unqualified names to shared file.
For current releases of gdb, `extract_type_name` should just be a no-op.
Fixes#35155
Use monotonic time in condition variables.
Configure condition variables to use monotonic time using
pthread_condattr_setclock on systems where this is possible.
This fixes the issue when thread waiting on condition variable is
woken up too late when system time is moved backwards.
These are exactly equivalent to PR #35809, with one caveat: I do not believe there is a non-bitwise binary "xor" operator in Rust, so here it's expressed as (a || b) && !(a && b).
r? @GuillaumeGomez
improved documentation a la PR #35993
Update E0194 to new error format
Fixes#35280 to update E0194 to support new error message format. Part of #35233.
A separate Github issue #36057 tracks the bonus portion of the original ticket.
r? @jonathandturner
improve `BitAnd` trait documentation
This pull request is based on the discussion in PR #35927.
Add a module-level note that `&&` and `||` are short-circuiting operators and not overloadable.
Add a simple `Scalar` example that lifts the `&` operator to a trivial struct tuple.
Make `BooleanVector` a struct tuple.
Derive `PartialEq` for `BooleanVector` instead of implementing it.
Adds a `fn main` wrapper so that the example can integrate with Rust Playground.
Updated code sample in chapter on syntax extensions.
The affected API apparently had changed with commit d59accfb06.
---
Further more I had to add
```toml
[lib]
name = "roman_numerals"
crate-type = ["dylib"]
```
to `Cargo.toml` as I otherwise got this compiler error (despite `#![crate_type="dylib"]`):
[E0457]: plugin `roman_numerals` only found in rlib format, but must be available in dylib format
Might be worth adding a note about that?
