Add suggestion `.collect()` for iterators in iterators
Closes#81584
```
error[E0515]: cannot return value referencing function parameter `y`
--> main3.rs:4:38
|
4 | ... .map(|y| y.iter().map(|x| x + 1))
| -^^^^^^^^^^^^^^^^^^^^^^
| |
| returns a value referencing data owned by the current function
| `y` is borrowed here
| help: Maybe use `.collect()` to allocate the iterator
```
Added the suggestion: `help: Maybe use `.collect()` to allocate the iterator`
Implement NOOP_METHOD_CALL lint
Implements the beginnings of https://github.com/rust-lang/lang-team/issues/67 - a lint for detecting noop method calls (e.g, calling `<&T as Clone>::clone()` when `T: !Clone`).
This PR does not fully realize the vision and has a few limitations that need to be addressed either before merging or in subsequent PRs:
* [ ] No UFCS support
* [ ] The warning message is pretty plain
* [ ] Doesn't work for `ToOwned`
The implementation uses [`Instance::resolve`](https://doc.rust-lang.org/nightly/nightly-rustc/rustc_middle/ty/instance/struct.Instance.html#method.resolve) which is normally later in the compiler. It seems that there are some invariants that this function relies on that we try our best to respect. For instance, it expects substitutions to have happened, which haven't yet performed, but we check first for `needs_subst` to ensure we're dealing with a monomorphic type.
Thank you to ```@davidtwco,``` ```@Aaron1011,``` and ```@wesleywiser``` for helping me at various points through out this PR ❤️.
Add option to enable MIR inlining independently of mir-opt-level
Add `-Zinline-mir` option that enables MIR inlining independently of the
current MIR opt level. The primary use-case is enabling MIR inlining on the
default MIR opt level.
Turn inlining thresholds into optional values to make it possible to configure
different defaults depending on the current mir-opt-level (although thresholds
are yet to be used in such a manner).
The storage markers constitute a substantial portion of all MIR
statements. At the same time, for builds without any optimizations,
the storage markers have no further use during and after MIR
optimization phase.
If storage markers are not necessary for code generation, remove them.
Use small hash set in `mir_inliner_callees`
Use small hash set in `mir_inliner_callees` to avoid temporary
allocation when possible and quadratic behaviour for large number of
callees.
Consider inexpensive inlining criteria first
Refactor inlining decisions so that inexpensive criteria are considered first:
1. Based on code generation attributes.
2. Based on MIR availability (examines call graph).
3. Based on MIR body.
[librustdoc] Only split lang string on `,`, ` `, and `\t`
Split markdown lang strings into tokens on `,`.
The previous behavior was to split lang strings into tokens on any
character that wasn't a `_`, `_`, or alphanumeric.
This is a potentially breaking change, so please scrutinize! See discussion in #78344.
I noticed some test cases that made me wonder if there might have been some reason for the original behavior:
```
t("{.no_run .example}", false, true, Ignore::None, true, false, false, false, v(), None);
t("{.sh .should_panic}", true, false, Ignore::None, false, false, false, false, v(), None);
t("{.example .rust}", false, false, Ignore::None, true, false, false, false, v(), None);
t("{.test_harness .rust}", false, false, Ignore::None, true, true, false, false, v(), None);
```
It seemed pretty peculiar to specifically test lang strings in braces, with all the tokens prefixed by `.`.
I did some digging, and it looks like the test cases were added way back in [this commit from 2014](https://github.com/rust-lang/rust/commit/3fef7a74ca9a) by `@skade.`
It looks like they were added just to make sure that the splitting was permissive, and aren't testing that those strings in particular are accepted.
Closes https://github.com/rust-lang/rust/issues/78344.
Refactor inlining decisions so that inexpensive criteria are considered first:
1. Based on code generation attributes.
2. Based on MIR availability (examines call graph).
3. Based on MIR body.
Point out implicit deref coercions in borrow
Fixes#81365
`@Aaron1011` I'm not sure why my code shows the note even in an implicit `Deref` call. See the output for `issue-81365-8.rs`.
MIR-OPT: Pass to deduplicate blocks
This pass finds basic blocks that are completely equal,
and replaces all uses with just one of them.
```bash
$ RUSTC_LOG=rustc_mir::transform::deduplicate_blocks ./x.py build --stage 2 | grep "SUCCESS: Replacing: " > log
...
$ cat log | wc -l
23875
```
