Expand E0309 explanation with motivating example
I recently started reading @Gankro's "[Learning Rust With Entirely Too Many Linked Lists](http://cglab.ca/~abeinges/blah/too-many-lists/book/README.html)", and came across [a part](http://cglab.ca/~abeinges/blah/too-many-lists/book/second-iter.html) where he comes across `E0309`, and after showing `rustc --explain E0309` prompty says
> This is dumb. I think it's dumb. You have to do it.
Humor aside, I think this says something about the current explanation being somewhat lacking.
This patch introduces a motivating example saying why `T: 'a` is a necessary restriction. Hopefully, this will help new Rustaceans understand why leaving out the `'a` bound on `T` might lead to broken code.
A more verbose matching failure for mir tests
This makes it easier to work with mir test failures during development.
- Show which expected line was not found
- Show full expected output
- Show full actual output
Point out the known type when field doesn't satisfy bound
For file
```rust
use std::path::Path;
fn f(p: Path) { }
```
provide the following error
```nocode
error[E0277]: the trait bound `[u8]: std::marker::Sized` is not satisfied in `std::path::Path`
--> file.rs:3:6
|
3 | fn f(p: Path) { }
| ^ within `std::path::Path`, the trait `std::marker::Sized` is not implemented for `[u8]`
|
= note: `[u8]` does not have a constant size known at compile-time
= note: required because it appears within the type `std::path::Path`
= note: all local variables must have a statically known size
```
Fix#23286.
Add From<[u16; 8]> to Ipv6Addr
Not really sure that this requires an RFC, but I figured that I'd offer a pull request and see what people think. It seems like a reasonable addition.
Use Borrow for binary_search and contains methods in the standard library
Fixes all standard library methods in #32822 that can be fixed without backwards compatibility issues.
add preliminary support for incremental compilation to rustbuild.py
This implements the integration described in #37929. It requires the use of a local nightly as your bootstrap compiler. The setup is described in `src/bootstrap/README.md`.
This does NOT implement the "copy stage0 libs to stage1" optimization described in #37929, just because that seems orthogonal to me.
In local testing, I do not yet see any incremental re-use when building rustc. I'm not sure why that is, more investigation needed.
(For these reasons, this is not marked as fixing the relevant issue.)
r? @alexcrichton -- I included one random cleanup (`Step::noop()`) that turned out to not be especially relevant. Feel free to tell me you liked it better the old way.
rustbuild: Fix `copy` helper with existing files
This erroneously truncated files when the destination already existed and was an
existing hard link to the source. This in turn caused weird bugs!
Closes#37745
Use exec for the wrapper on UNIXes
This not only avoids the small – and unnecessary – constant overhead for each compiler invocation,
but also helps somewhat by only having “correct” rustc processes to look for in `/proc/`.
This also makes the wrapper behave effectively as a regular exec wrapper its intended to be.
I also took liberty to change the fallback error code from `1` to `0xfe` (now only relevant on windows) so that when people complain about “compiler exited with code 254”, its obvious where the issue lies (wrapper losing the exit code somehow).
r? @alexcrichton
Update beta bootstrap compiler
The current beta that rustc is bootstrapping from contains a bug in Cargo that
erroneously links to OpenSSL in /usr/local, but this is fixed in the most recent
1.14 beta, so let's use that.
tidy features: use 2-parameter form of internal try macro for open err
This tiny patch merely applies @bluss's suggestion for how to get a more
informative error message when the feature check can't open a file, a
matter that had briefly annoyed the present author, leading to the
filing of #38417.
Resolves#38417.
rustc: Disable NEON on armv7 android.
We thought Google's ABI for arvm7 required neon, but it is
currently optional, perhaps because there is a significant
population of Tegra 2 devices still in use.
This turns off neon code generation outside #[target-feature]
blocks just like we do on armv7-unknown-linux-gnu, but unlike
most other armv7 targets. LLVM defaults to +neon for this target,
so an explicit disable is necessary.
See https://developer.android.com/ndk/guides/abis.html#v7a
for instruction set extension requirements.
Closes#38402.
llvm: backport r280651
fixes#38406
r? @alexcrichton
(I'm secretly hoping this will error in the same way as #38314. That would sort of confirm that the problem is OOM and not enabling the SPARC backend)
Don't perform span mangling when building field/tup access nodes
There are no guarantees that the two spans used to create the new one
come from the same place or are even valid.
Fixes#36081.
