Renumber `proc_macro` tracking issues
Lots of issue links in the compiler still point to https://github.com/rust-lang/rust/issues/38356 which is a bit of a monster issue that isn't serving much purpose any more. I've split the issue into a number of more fine-grained tracking issues to track stabilizations.
do not promote comparing function pointers
This *could* break existing code that relied on fn ptr comparison getting promoted to `'static` lifetime.
Fixes https://github.com/rust-lang/rust/issues/54696
Use impl_header_lifetime_elision in libcore
The feature is approved for stabilization, so let's use it to remove about 300 `'a`s.
Tracking issue for the feature: https://github.com/rust-lang/rust/issues/15872
make run-pass tests with empty main just compile-pass tests
Many run-pass tests have an empty main, so there is not actually any point in running them. This makes them `compile-pass` tests instead, saving some time (generating the binary and then running it).
For now I did this only for `run-pass/issues`; if there is interest I can also do it for the other directories. I used `^\s*fn\s+main\(\s*\)\s*\{\s*\}` as regexp to identify these files.
Add `crate::` to trait suggestions in Rust 2018.
Fixes#54559.
In the 2018 edition, when suggesting traits to import that implement a
given method that is being invoked, suggestions will now include the
`crate::` prefix if the suggested trait is local to the current crate.
r? @nikomatsakis
Allow both explicit and elided lifetimes in the same impl header
While still prohibiting explicit and in-band in the same header.
Fixes#54456
As usual, I don't know the broader context of the code I'm changing, so please let me know whatever I can do better.
Pre-existing test that mixing explicit and in-band remains an error: https://github.com/rust-lang/rust/blob/master/src/test/ui/in-band-lifetimes/E0688.rs
#53840: Consolidate pattern check errors
#53840 on this PR we are aggregating `cannot bind by-move and by-ref in the same pattern` message present on the different lines into one diagnostic message. Here we are first gathering those `spans` on `vector` then we are throwing them with the help of `MultiSpan`
r? @estebank
Addresses: #53480
we are consolidating `cannot bind by-move and by-ref in the same
pattern` message present on the different lines into single diagnostic
message.
To do this, we are first gathering those spans into the vector
after that we are throwing them with the help of MultiSpan in
a separate block.
Addresses: #53840
normalize param-env type-outlives predicates last
The normalization of type-outlives predicates can depend on misc.
environment predicates, but not the other way around. Inferred lifetime
bounds can propagate type-outlives bounds far and wide, so their
normalization needs to work well.
Fixes#54467
r? @nikomatsakis
beta-nominating because this is required for inferred_outlives_bounds, which is in beta
In the 2018 edition, when suggesting traits to import that implement a
given method that is being invoked, suggestions will now include the
`crate::` prefix if the suggested trait is local to the current crate.
do not normalize all non-scalar constants to a ConstValue::ScalarPair
We still need `ConstValue::ScalarPair` for match handling (matching slices and strings), but that will never see anything `Undef`. For non-fat-ptr `ScalarPair`, just point to the allocation like larger data structures do.
Fixes https://github.com/rust-lang/rust/issues/54387
r? @eddyb
The normalization of type-outlives predicates can depend on misc.
environment predicates, but not the other way around. Inferred lifetime
bounds can propagate type-outlives bounds far and wide, so their
normalization needs to work well.
Fixes#54467
Panic when using mem::uninitialized or mem::zeroed on an uninhabited type
All code by @japaric. This re-submits one half of https://github.com/rust-lang/rust/pull/53508. This is likely not the one that introduced the perf regression, but just to be sure I'll do a perf run anyway.
Remove `-Z disable_ast_check_for_mutation_in_guard`
One should use `#![feature(bind_by_move_pattern_guards)]` over `-Z disable_ast_check_for_mutation_in_guard`
cc #15287
Don't lint non-extern-prelude extern crate's in Rust 2018.
Fixes#54381 by silencing the lint telling users to remove `extern crate` when `use` doesn't work.
r? @alexcrichton cc @petrochenkov @nikomatsakis @Centril
Add a per-tree error cache to the obligation forest
This implements part of what @nikomatsakis mentioned in https://github.com/rust-lang/rust/pull/30533#issuecomment-170705871:
> 1. If you find that a new obligation is a duplicate of one already in the tree, the proper processing is:
> * if that other location is your parent, you should abort with a cycle error (or accept it, if coinductive)
> * if that other location is not an ancestor, you can safely ignore the new obligation
In particular it implements the "if that other location is your parent accept it, if coinductive" part. This fixes#40827.
I have to say that I'm not 100% confident that this is rock solid. This is my first pull request 🎉, and I didn't know anything about the trait resolver before this. In particular I'm not totally sure that comparing predicates is enough (for instance, do we need to compare `param_env` as well?). Also, I'm not sure what @nikomatsakis mentions [here](https://github.com/rust-lang/rust/issues/30977#issue-127091096), but it might be something that affects this PR:
> In particular, I am wary of getting things wrong around inference variables! We can always add things to the set in their current state, and if unifications occur then the obligation is just kind of out-of-date, but I want to be sure we don't accidentally fail to notice that something is our ancestor. I decided this was subtle enough to merit its own PR.
Anyway, go ahead and review 🙂.
Ref #30977.
# Performance
We are now copying vectors around, so I decided to do some benchmarking. A simple benchmark shows that this does not seem to affect performance in a measurable way:
I ran `cargo clean && cargo build` 20 times on actix-web (84b27db) and these are the results:
```text
rustc master:
Mean Std.Dev. Min Median Max
real 66.637 2.996 57.220 67.714 69.314
user 307.293 14.741 258.093 312.209 320.702
sys 12.524 0.653 10.499 12.726 13.193
rustc fix-bug-overflow-send:
Mean Std.Dev. Min Median Max
real 66.297 4.310 53.532 67.516 70.348
user 306.812 22.371 236.917 314.748 326.229
sys 12.757 0.952 9.671 13.125 13.544
```
I will do a more comprehensive benchmark (compiling rustc stage1) and post the results.
r? @nikomatsakis, @nnethercote
PS: It is better to review this commit-by-commit.
Enable NLL compare mode for more tests
Most of these tests were disabled due to NLL bugs that have since been fixed. A few needed updating for NLL.
r? @nikomatsakis
Do not put noalias annotations by default
This will be re-enabled sooner or later depending on results of further
investigation.
Fixes#54462
Beta backport is: #54640
r? @nikomatsakis
use closure def-id in returns, but base def-id in locals
The refactorings to handle `let x: impl Trait` wound up breaking `impl Trait` in closure return types. I think there are some deeper problems with the code in question, but this a least should make @eddyb's example work.
Fixes#54593
r? @eddyb
