As a driveby change, I made `#![feature(nll)]` *always* take
precedence over `-Z borrowck`. The main effect this had is that it
means tests with `#![feature(nll)]` will ignore uses of `-Z
borrowck=compare`. This affected only one test as far as I can tell,
and I think that test used `-Z borrowck=compare` only as a historical
accident.
Note that this test is carefully crafted to *try* to not segfault
during its run. Howver, it really is representing unsound code that
should be rejected after we manage to remove the AST-borrowck entirely
from the compiler.
Do not suggest using `to_owned()` on `&str += &str`
- Don't provide incorrect suggestion for `&str += &str` (fix#52410)
- On `&str + String` suggest `&str.to_owned() + &String` as a single suggestion
LHS of assign op is invariant
This addresses a bug injected by #45435. That PR changed the way we type-check `LHS <op> RHS` to coerce the LHS to the expected supertype in much the same way that we coerce the RHS.
The problem is that when we have a case of `LHS <op>= RHS`, we do not want to coerce to a supertype; we need the type to remain invariant. Otherwise we risk leaking a value with short-lifetimes into a expression context that needs to satisfy a long lifetime.
Fix#52126
add structured suggestions and fix false-positive for elided-lifetimes-in-paths lint
This adds structured suggestions to the elided-lifetimes-in-paths lint (introduced in Nov. 2017's #46254), prevents it from emitting a false-positive on anonymous (underscore) lifetimes (!), and adds it to the idioms-2018 group (#52041).
~~As an aside, "elided-lifetimes-in-paths" seems like an unfortunate name, because it's not clear exactly what "elided" means. The motivation for this lint (see original issue #45992, and [RFC 2115](e978a8d301/text/2115-argument-lifetimes.md (motivation))) seems to be specifically about not supplying angle-bracketed lifetime arguments to non-`&` types, but (1) the phrase "lifetime elision" has historically also referred to the ability to not supply a lifetime name to `&` references, and (2) an `is_elided` method in the HIR returns true for anoymous/underscore lifetimes, which is _not_ what we're trying to lint here. (That naming confusion is almost certainly what led to the false positive addressed here.) Given that the lint is relatively new and is allow-by-default, is it too late to rename it ... um, _again_ (#50879)?~~
~~This does _not_ address a couple of other false positives discovered in https://github.com/rust-lang/rust/issues/52041#issuecomment-402547901.~~
r? @nikomatsakis
cc @nrc @petrochenkov
Rollup of 11 pull requests
Successful merges:
- #51807 (Deprecation of str::slice_unchecked(_mut))
- #52051 (mem::swap the obvious way for types smaller than the SIMD optimization's block size)
- #52465 (Add CI test harness for `thumb*` targets. [IRR-2018-embedded])
- #52507 (Reword when `_` couldn't be inferred)
- #52508 (Document that Unique::empty() and NonNull::dangling() aren't sentinel values)
- #52521 (Fix links in rustdoc book.)
- #52581 (Avoid using `#[macro_export]` for documenting builtin macros)
- #52582 (Typo)
- #52587 (Add missing backtick in UniversalRegions doc comment)
- #52594 (Run the error index tool against the sysroot libdir)
- #52615 (Added new lines to .gitignore.)
The existing elided-lifetimes-in-paths lint (introduced in Nov. 2017's
accd997b5 / #46254) lacked stuctured suggestions and—much more
alarmingly—produced false positives on associated functions (like
`Ref::clone`) and on anonymous '_ lifetimes (!!—yes, the very
anonymous lifetimes that we meant to suggest "instead"). That this
went apparently unnoticed for so long maybe tells you something about
how many people actually bother to flip on allow-by-default lints.
After many hours of good old-fashioned American elbow grease—and a
little help from expert reviewers—it turns out that getting the right
answer is a lot easier if we fire the lint while lowering the Higher
Intermediate Representation.
The lint is promoted to the idioms-2018 group.
Also, in the matter of test filenames, "elided" only has one 'l' (see,
e.g., https://en.wiktionary.org/wiki/elide).
Resolves#52041.
[NLL] Small move error reporting improvements
* Use a MirBorrowckContext when reporting errors to be more uniform with other error reporting
* Add a special message for the case of trying to move from capture variables in `Fn` and `FnMut` closures.
part of #51028
Improve suggestion for missing fmt str in println
Avoid using `concat!(fmt, "\n")` to improve the diagnostics being
emitted when the first `println!()` argument isn't a formatting string
literal.
Fix#52347.
Turn implied_outlives_bounds into a query
Right now all this does is remove the error reporting in `implied_outlives_bounds`, which seems to work. Farming out full tests to Travis.
For #51649. That issue is deferred so not sure what's next.
r? @nikomatsakis
[NLL] Mutability errors
cc #51028
cc #51170
cc #46559Closes#46629
* Better explain why the place is immutable ("immutable item" is gone)
* Distinguish &T and *const T
* Use better spans when a mutable borrow is for a closure capture
r? @pnkfelix
resolve: Some renaming, refactoring and comments
Commits are self-descriptive.
The only functional change is 34bf2f572e that tightens shadowing rules for macro paths (makes the second and third cases in `test/ui/imports/glob-shadowing.rs` an error).
Const propagate casts
fixes#49760
So... This fixes the original issue about the missing warnings.
But our test suite contains fun things like
```rust
fn foo() {}
assert_eq!(foo as i16, foo as usize as i16);
```
Which, will result in
> a raw memory access tried to access part of a pointer value as raw bytes
on both sides of the assertion. Because well... that's exactly what's going on! We're ripping out 16 bits of a pointer.
Squash all lints tied to foreign macros by default
This PR is a continuation of https://github.com/rust-lang/rust/pull/49755 (thanks for the initial jump-start @Dylan-DPC!) and is targeted at solving https://github.com/rust-lang/rust/issues/48855. This change updates the lint infrastructure to, by default, ignore all lints emitted for code that originates in a foreign macro. For example if `println!("...")` injects some idiomatic warnings these are all ignored by default. The rationale here is that for almost all lints there's no action that can be taken if the code originates from a foreign lint.
Closes#48855Closes#52483Closes#52479
rustc: Stabilize #[wasm_import_module] as #[link(...)]
This commit stabilizes the `#[wasm_import_module]` attribute as
`#[link(wasm_import_module = "...")]`. Tracked by #52090 this new directive in
the `#[link]` attribute is used to configured the module name that the imports
are listed with. The WebAssembly specification indicates two utf-8 names are
associated with all imported items, one for the module the item comes from and
one for the item itself. The item itself is configurable in Rust via its
identifier or `#[link_name = "..."]`, but the module name was previously not
configurable and defaulted to `"env"`. This commit ensures that this is also
configurable.
Closes#52090
When encountering format string errors in a raw string, or regular
string literal with embedded newlines, account for the positional
change to use correct spans.
:drive by fix: 🚗
- Don't print the newline on its own to avoid the possibility of
printing it out of order due to `stdout` locking.
- Modify wording of `concat!()` with non-literals to not mislead into
believing that only `&str` literals are accepted.
- Add test for `concat!()` with non-literals.
