cleanup more iterator usages (and other things)
* Improve weird formatting by moving comment inside else-code block.
* Use .any(x) instead of .find(x).is_some() on iterators.
* Use .nth(x) instead of .skip(x).next() on iterators.
* Simplify conditions like x + 1 <= y to x < y
* Use let instead of match to get value of enum with single variant.
miri engine: turn some debug_assert into assert
@eddyb said to avoid debug assertions in rustc. These checks here look like they are probably not too expensive. Cc @oli-obk
Improve linking of crates with circular dependencies
Previously, the code responsible for handling the cycles between crates
introduces through weak lang items, would keep a set of missing language
items:
* extending it with items missing from the current crate,
* removing items provided by the current crate,
* grouping the crates when the set changed from non-empty back to empty.
This could produce incorrect results, if a lang item was missing from a
crate that comes after the crate that provides it (in the loop iteration
order). In that case the grouping would not take place.
The changes here address this specific failure scenario by keeping track
of two separate sets of crates. Those that are required to link successfully,
and those that are available for linking.
Verified using test case from #69368.
Polonius: update `polonius-engine` to 0.12.0
Since @albins won't have the time to finish up #68993 for a while, I'll take care of the trivial remaining tasks (rebasing, taking care of tidy/rustfmt).
I'll r? @nikomatsakis since they're assigned to #68993, but have actually [already reviewed it pre-rebase](https://github.com/rust-lang/rust/pull/68993#issuecomment-586413089).
When CI passes: I'll notify bors and close#68993, since this PR supersedes it.
Previously, the code responsible for handling the cycles between crates
introduces through weak lang items, would keep a set of missing language
items:
* extending it with items missing from the current crate,
* removing items provided by the current crate,
* grouping the crates when the set changed from non-empty back to empty.
This could produce incorrect results, if a lang item was missing from a
crate that comes after the crate that provides it (in the loop iteration
order). In that case the grouping would not take place.
The changes here address this specific failure scenario by keeping track
of two separate sets of crates. Those that are required to link successfully,
and those that are available for linking.
Verified using test case from 69368.
more cleanups
* use starts_with() instead of chars().next() == Some(x)
* use subsec_micros() instead of subsec_nanos() / 1000
* use for (idx, item) in iter.enumerate() instead of manually counting loop iterations with variables
* use values() or keys() respectively when iterating only over keys or values of maps.
Remove `usable_size` APIs
This removes the usable size APIs:
- remove `usable_size` (obv)
- change return type of allocating methods to include the allocated size
- remove `_excess` API
r? @Amanieu
closesrust-lang/wg-allocators#17
Remove experimental chalk option
As suggested by @nikomatsakis [here](https://github.com/rust-lang/rust/pull/68807#issuecomment-583339932).
The current version of chalk used by the experimental `-Zchalk` flag is [v0.9.0, which is over a year old](https://crates.io/crates/chalk-engine). Since v0.9.0, chalk has seen [a lot of further development](https://github.com/rust-lang/chalk/compare/41dfe13...master), and the intent is to eventually upgrade rustc to use a more recent chalk.
However, it will take a decent chunk of effort to upgrade the current experimental chalk support, and it is currently [blocking at least some PRs](https://github.com/rust-lang/rust/pull/68807) due to chalk:0.9.0's use of unstable features. So for the interim until the next chalk release and experimental rustc integration, we remove the chalk-specific code from rustc.
Toolstate: Don't block beta week on already broken tools.
This changes it so that tools are allowed to be broken entering the beta week if they are already broken. This restores the original behavior before the changes in #69332.
Closes#68458
Unrevert "Remove `checked_add` in `Layout::repeat`"
This reapplies @kraai's original `libcore::alloc::Layout::repeat` change from #67174 which was temporarily reverted in #69241. Now that the proper LLVM fix has been cherry-picked, we can unrevert the revert.
This change was originally reviewed by @hanna-kruppe on the initial PR.
cc @RalfJung
Add documentation to compiler intrinsics
This adds documentation to the compiler intrinsics having stable standard implementations.
Relates to #34338 (cc @bstrie)
r? @steveklabnik (for reassignment?)
Adjust Miri value visitor, and doc-comment layout components
I realized that I still didn't have quite the right intuition for how our `LayoutDetails` work, so I had to adjust the Miri value visitor to the things I understood better now. I also added some doc-comments to `LayoutDetails` as a hopefully canonical place to note such things.
The main visitor change is that we *first* look at all the fields (according to `FieldPlacement`), and *then* check the variants and handle `Multiple` appropriately. I did not quite realize how orthogonal "fields" and "variants" are.
I also moved the check for the scalar ABI to *after* checking all the fields; this leads to better (more type-driven) error messages.
And it looks like we can finally remove that magic hack for `ty::Generator`. :D
r? @oli-obk for the Miri/visitor changes and @eddyb for the layout docs
The Miri PR is at: https://github.com/rust-lang/miri/pull/1178
Clean up TypeFlags
* Add a new method `has_infer_types_or_consts` that's used instead of `has_infer_types` most of the time, since there's generally no reason to only consider types.
* Remove `has_closure_types`/`HAS_TY_CLOSURE`, because closures are no longer implicitly linked to the `InferCtxt`.
* Reorder flags to group similar ones together
* Make some flags more granular
* Compute `HAS_FREE_LOCAL_NAMES` from the other flags
* Add some more doc comments
`--explain` disambiguates no long description and invalid error codes
Closes#44710
First code contribution here, so feedback is very much appreciated!
cc @zackmdavis
cc @Mark-Simulacrum
rustc_metadata: Load metadata for indirect macro-only dependencies
Imagine this dependency chain between crates
```
Executable crate -> Library crate -> Macro crate
```
where "Library crate" uses the macros from "Macro crate" for some code generation, but doesn't reexport them any further.
Currently, when compiling "Executable crate" we don't even load metadata for it, because why would we want to load any metadata from "Macro crate" if it already did all its code generation job when compiling "Library crate".
Right?
Wrong!
Hygiene data and spans (https://github.com/rust-lang/rust/issues/68686, https://github.com/rust-lang/rust/pull/68941) from "Macro crate" still may need to be decoded from "Executable crate".
So we'll have to load them properly.
Questions:
- How this will affect compile times for larger crate trees in practice? How to measure it?
Hygiene/span encoding/decoding will necessarily slow down compilation because right now we just don't do some work that we should do, but this introduces a whole new way to slow down things. E.g. loading metadata for `syn` (and its dependencies) when compiling your executable if one of its library dependencies uses it.
- We are currently detecting whether a crate reexports macros from "Macro crate" or not, could we similarly detect whether a crate "reexports spans" and keep it unloaded if it doesn't?
Or at least "reexports important spans" affecting hygiene, we can probably lose spans that only affect diagnostics.
