There is a logical issue around what counts as leading white-space.
There is code which does a subtraction assuming that no errors will be reported
inside the leading whitespace. However we compute the length of
that whitespace with std::char::is_whitespace and not
rustc_lexer::is_whitespace. The former will include a no-break space while
later will excluded it. We can only safely make the assumption that no errors
will be reported in whitespace if it is all "Rust Standard" whitespace.
Indeed an error does occur in unicode whitespace if it contains a no-break
space.
Consider comments and bare delimiters the same as an "empty line" for purposes of hiding rendered code output of long multispans. This results in more aggressive shortening of rendered output without losing too much context, specially in `*.stderr` tests that have "hidden" comments.
Remove the "which is required by `{root_obligation}`" post-script in
"the trait `X` is not implemented for `Y`" explanation in E0277. This
information is already conveyed in the notes explaining requirements,
making it redundant while making the text (particularly in labels)
harder to read.
```
error[E0277]: the trait bound `NotCopy: Copy` is not satisfied
--> $DIR/wf-static-type.rs:10:13
|
LL | static FOO: IsCopy<Option<NotCopy>> = IsCopy { t: None };
| ^^^^^^^^^^^^^^^^^^^^^^^ the trait `Copy` is not implemented for `NotCopy`
|
= note: required for `Option<NotCopy>` to implement `Copy`
note: required by a bound in `IsCopy`
--> $DIR/wf-static-type.rs:7:17
|
LL | struct IsCopy<T:Copy> { t: T }
| ^^^^ required by this bound in `IsCopy`
```
vs the prior
```
error[E0277]: the trait bound `NotCopy: Copy` is not satisfied
--> $DIR/wf-static-type.rs:10:13
|
LL | static FOO: IsCopy<Option<NotCopy>> = IsCopy { t: None };
| ^^^^^^^^^^^^^^^^^^^^^^^ the trait `Copy` is not implemented for `NotCopy`, which is required by `Option<NotCopy>: Copy`
|
= note: required for `Option<NotCopy>` to implement `Copy`
note: required by a bound in `IsCopy`
--> $DIR/wf-static-type.rs:7:17
|
LL | struct IsCopy<T:Copy> { t: T }
| ^^^^ required by this bound in `IsCopy`
```
Implement RFC3137 trim-paths sysroot changes - take 2
This PR is a continuation of https://github.com/rust-lang/rust/pull/118149. Nothing really changed, except for https://github.com/rust-lang/rust/pull/129408 which I was able to trigger locally.
Original description:
> Implement parts of #111540
>
> Right now, backtraces into sysroot always shows /rustc/$hash in diagnostics, e.g.
>
> ```
> thread 'main' panicked at 'hello world', map-panic.rs:2:50
> stack backtrace:
> 0: std::panicking::begin_panic
> at /rustc/a55dd71d5fb0ec5a6a3a9e8c27b2127ba491ce52/library/std/src/panicking.rs:616:12
> 1: map_panic::main::{{closure}}
> at ./map-panic.rs:2:50
> 2: core::option::Option<T>::map
> at /rustc/a55dd71d5fb0ec5a6a3a9e8c27b2127ba491ce52/library/core/src/option.rs:929:29
> 3: map_panic::main
> at ./map-panic.rs:2:30
> 4: core::ops::function::FnOnce::call_once
> at /rustc/a55dd71d5fb0ec5a6a3a9e8c27b2127ba491ce52/library/core/src/ops/function.rs:248:5
> note: Some details are omitted, run with `RUST_BACKTRACE=full` for a verbose backtrace.
> ```
>
> [RFC 3127 said](https://rust-lang.github.io/rfcs/3127-trim-paths.html#changing-handling-of-sysroot-path-in-rustc)
>
> > We want to change this behaviour such that, when rust-src source files can be discovered, the virtual path is discarded and therefore the local path will be embedded, unless there is a --remap-path-prefix that causes this local path to be remapped in the usual way.
>
> This PR implements this behaviour. When `rust-src` is present at compile time, rustc replaces /rustc/$hash with a real path into local rust-src with best effort. To sanitise this, users must explicitly supply `--remap-path-prefix=<path to rust-src>=foo`.
cc `@cbeuw`
Fix#105907Fix#85463
try-job: dist-x86_64-linux
try-job: x86_64-msvc
try-job: dist-x86_64-msvc
try-job: armhf-gnu
This is done to cover the path of the test it-self as it may not live
on the same root directory as {{rust-src-base}}, which can be the case
if {{rust-src-base}} is coming from a extracted dist build (cc opt-dist)
Expand the primary span of E0277 when the immediate unmet bound is not what the user wrote:
```
error[E0277]: the trait bound `i32: Bar` is not satisfied
--> f100.rs:6:6
|
6 | <i32 as Foo>::foo();
| ^^^ the trait `Bar` is not implemented for `i32`, which is required by `i32: Foo`
|
help: this trait has no implementations, consider adding one
--> f100.rs:2:1
|
2 | trait Bar {}
| ^^^^^^^^^
note: required for `i32` to implement `Foo`
--> f100.rs:3:14
|
3 | impl<T: Bar> Foo for T {}
| --- ^^^ ^
| |
| unsatisfied trait bound introduced here
```
Fix#40120.
