Suggest calling closure with resolved return type when appropriate
Follow up to #63337. CC #63100.
```
error[E0308]: mismatched types
--> $DIR/fn-or-tuple-struct-without-args.rs:46:20
|
LL | let closure = || 42;
| -- closure defined here
LL | let _: usize = closure;
| ^^^^^^^
| |
| expected usize, found closure
| help: use parentheses to call this closure: `closure()`
|
= note: expected type `usize`
found type `[closure@$DIR/fn-or-tuple-struct-without-args.rs:45:19: 45:24]`
```
Tweak E0308 on opaque types
```
error[E0308]: if and else have incompatible types
--> file.rs:21:9
|
18 | / if true {
19 | | thing_one()
| | ----------- expected because of this
20 | | } else {
21 | | thing_two()
| | ^^^^^^^^^^^ expected opaque type, found a different opaque type
22 | | }.await
| |_____- if and else have incompatible types
|
= note: expected type `impl std::future::Future` (opaque type)
found type `impl std::future::Future` (opaque type)
= note: distinct uses of `impl Trait` result in different opaque types
= help: if both futures resolve to the same type, consider `await`ing on both of them
```
r? @Centril
CC #63167
rustc: implement argsfiles for command line
Many tools, such as gcc and gnu-ld, support "args files" - that is, being able to specify @file on the command line. This causes `file` to be opened and parsed for command line options. They're separated with whitespace; whitespace can be quoted with double or single quotes, and everything can be \\-escaped. Args files may recursively include other args files via `@file2`.
See https://sourceware.org/binutils/docs/ld/Options.html#Options for the documentation of gnu-ld's @file parameters.
This is useful for very large command lines, or when command lines are being generated into files by other tooling.
Improve diagnostics: break/continue in wrong context
- Fix#63712
- Use `` `break` `` or `` `continue` `` instead of always `break` in `cannot _...`
- Show the enclosing closure or async block we're talking about
- `` `break` outside of loop `` -> `` `break` outside of a loop `` for consistency
r? @estebank
This will make @path work with miri and other non-standard entrypoints.
Also since this simplifies librustc_driver::args, move it into a simple source file. Also
remove the tests since they're doing nothing more than checking `str::lines` has the right
behaviour.
rustc_mir: fix miri substitution/"universe" discipline.
Alternative to #61041, based on @RalfJung's own attempt at it.
I haven't done a full audit, but I believe everything is fixed now.
Fixes#61432.
Closes#61336, as a drive-by fix (for a subset of #43408, that is already special-cased).
r? @oli-obk / @RalfJung cc @varkor @yodaldevoid
This makes `rustc` support `@path` arguments on the command line. The `path` is opened and the file is interpreted
as new command line options which are logically inserted at that point in the command-line. The options in the file
are one per line. The file is UTF-8 encoded, and may have either Unix or Windows line endings.
It does not support recursive use of `@path`.
This is useful for very large command lines, or when command-lines are being generated into files by other tooling.
Fix suggestion from incorrect `move async` to `async move`.
PR for #61920. Happy with the test. There must be a better implementation though - possibly a MIR visitor to estabilsh a span that doesn't include the `async` keyword?
Currently the default is "inherited" from context, so e.g. `&impl
Foo<Item = dyn Bar>` would default to `&'x impl Foo<Item = dyn Bar +
'x>`, but this triggers an ICE and is not very consistent.
This patch doesn't implement what I expect would be the correct
semantics, because those are likely too complex. Instead, it handles
what I'd expect to be the common case -- where the trait has no
lifetime parameters.
Object-lifetime-default elision is distinct from other forms of
elision; it always refers to some enclosing lifetime *present in the
surrounding type* (e.g., `&dyn Bar` expands to `&'a (dyn Bar + 'a)`.
If there is no enclosing lifetime, then it expands to `'static`.
Therefore, in an `impl Trait<Item = dyn Bar>` setting, we don't expand
to create a lifetime parameter for the `dyn Bar + 'X` bound. It will
just be resolved to `'static`.
Annoyingly, the responsibility for this resolution is spread across
multiple bits of code right now (`middle::resolve_lifetimes`,
`lowering`). The lowering code knows that the default is for an object
lifetime, but it doesn't know what the correct result would be.
Probably this should be fixed, but what we do now is a surgical fix:
we have it generate a different result for elided lifetimes in a
object context, and then we can ignore those results when figuring out
the lifetimes that are captured in the opaque type.
