Fix issue #52475: Make loop detector only consider reachable memory
As [suggested](https://github.com/rust-lang/rust/pull/51702#discussion_r197585664) by @oli-obk `alloc_id`s should be ignored by traversing all `Allocation`s in interpreter memory at a given moment in time, beginning by `ByRef` locals in the stack.
- [x] Generalize the implementation of `Hash` for `EvalSnapshot` to traverse `Allocation`s
- [x] Generalize the implementation of `PartialEq` for `EvalSnapshot` to traverse `Allocation`s
- [x] Commit regression tests
Fixes#52626
Fixes https://github.com/rust-lang/rust/issues/52849
rustc_typeck: turn `where Type:,` into a WF(Type) predicate, instead of ignoring it.
Fixes#53696, assuming crater doesn't catch anyone using this syntax already.
Allowing an empty list of bounds in the grammar was done for the benefit of macro authors, most of which would *probably* be using it for bounds on type parameters, which are always WF.
r? @nikomatsakis cc @petrochenkov
Various small diagnostic and code clean up
- Point at def span on incorrect `panic` or `oom` function
- Use structured suggestion instead of note for `+=` that can be performed on a dereference of the left binding
- Small code formatting cleanup
set cfg(rustdoc) when rustdoc is running on a crate
When using `#[doc(cfg)]` to document platform-specific items, it's a little cumbersome to get all the platforms' items to appear all at once. For example, the standard library adds `--cfg dox` to rustdoc's command line whenever it builds docs, and the documentation for `#![feature(doc_cfg)]` suggests using a Cargo feature to approximate the same thing. This is a little awkward, because you always need to remember to set `--features dox` whenever you build documentation.
This PR proposes making rustdoc set `#[cfg(rustdoc)]` whenever it runs on a crate, to provide an officially-sanctioned version of this that is set automatically. This way, there's a standardized way to declare that a certain version of an item is specifically when building docs.
To try to prevent the spread of this feature from happening too quickly, this PR also restricts the use of this flag to whenever `#![feature(doc_cfg)]` is active. I'm sure there are other uses for this, but right now i'm tying it to this feature. (If it makes more sense to give this its own feature, i can easily do that.)
Implement the `min_const_fn` feature gate
cc @RalfJung @eddyb
r? @Centril
implements the feature gate for #53555
I added a hack so the `const_fn` feature gate also enables the `min_const_fn` feature gate. This ensures that nightly users of `const_fn` don't have to touch their code at all.
The `min_const_fn` checks are run first, and if they succeeded, the `const_fn` checks are run additionally to ensure we didn't miss anything.
Fix promotion stability hole in old borrowck
r? @nikomatsakis
I screwed up the promotion stability checks. Big time. They were basically nonexistant. We had tests for it. I also screwed up said tests. This is in stable already :(
Basically stability checks of promotion only worked if you tried to use a const fn defined in the same crate.
cc @eddyb
Generalize `async_idents` to all new keywords
This commit generalizes the existing `async_idents` lint to easily encompass
other identifiers that will be keywords in future editions. The new lint is
called `keyword_idents` and the old `async_idents` lint is registered as renamed
to this new lint.
As a proof of concept the `try` keyword was added to this list as it looks to be
listed as a keyword in the 2018 edition only. The `await` keyword was not added
as it's not listed as a keyword yet.
Closes#53077
This commit generalizes the existing `async_idents` lint to easily encompass
other identifiers that will be keywords in future editions. The new lint is
called `keyword_idents` and the old `async_idents` lint is registered as renamed
to this new lint.
As a proof of concept the `try` keyword was added to this list as it looks to be
listed as a keyword in the 2018 edition only. The `await` keyword was not added
as it's not listed as a keyword yet.
Closes#53077
rustc: Suggest removing `extern crate` in 2018
This commit updates the `unused_extern_crates` lint to make automatic
suggestions about removing `extern crate` annotations in the 2018 edition. This
ended up being a little easier than originally though due to what's likely been
fixed issues in the resolver!
Closes#52829
Miri engine cleanup
* Unify the two maps in memory to store the allocation and its kind together.
* Share the handling of statics between CTFE and miri: The miri engine always
uses "lazy" `AllocType::Static` when encountering a static. Acessing that
static invokes CTFE (no matter the machine). The machine only has any
influence when writing to a static, which CTFE outright rejects (but miri
makes a copy-on-write).
* Add an `AllocId` to by-ref consts so miri can use them as operands without
making copies.
* Move responsibilities around for the `eval_fn_call` machine hook: The hook
just has to find the MIR (or entirely take care of everything); pushing the
new stack frame is taken care of by the miri engine.
* Expose the intrinsics and lang items implemented by CTFE so miri does not
have to reimplement them.
* Allow Machine to hook into foreign statics (used by miri to get rid of some other hacks).
* Clean up function calling.
* Switch const sanity check to work on operands, not mplaces.
* Move const_eval out of rustc_mir::interpret, to make sure that it does not access private implementation details.
In particular, we can finally make `eval_operand` take `&self`. :-)
Should be merged after https://github.com/rust-lang/rust/pull/53609, across which I will rebase.
Warn on anon params in 2015 edition
cc #41686https://github.com/rust-lang/rfcs/pull/2522
cc @Centril @nikomatsakis
TODO:
- [x] Make sure the tests pass.
- [x] Make sure there is rustfix-able suggestion. Current plan is to just suggest `_ : Foo`
- [x] Add a rustfix ui test.
EDIT: It seems I already did the last two in #48309
