bors [Fri, 25 Jun 2021 01:23:16 +0000 (01:23 +0000)]
Auto merge of #86574 - m-ou-se:or-pattern-lint-fix, r=petrochenkov
Don't lint :pat when re-parsing a macro from another crate.
`compile_macro` is used both when compiling the original definition in the crate that defines it, and to compile the macro when loading it when compiling a crate that uses it. We should only emit lints in the first case.
This adds a `is_definition: bool` to pass this information in, so we don't warn about things that only concern the definition site.
bors [Thu, 24 Jun 2021 22:42:26 +0000 (22:42 +0000)]
Auto merge of #86272 - nagisa:nagisa/tidy-llvm-components, r=Mark-Simulacrum
tidy: verify that test revisions with --target have associated needs-llvm-components directives
This ensures that people who tend to write `--target` `#[no_core]` tests don't miss specifying the `needs-llvm-components` directive. This is necessary for the test suite to pass when LLVM is compiled with a subset of components enabled.
While here I also took the opportunity to implement a more fine-grained handling of the ignore directives, so that they are evaluated for each revision, rather than for the entire test. With this even if people have `arm` component disabled, only the revision that depends on the arm component will not run.
Otherwise something that ought to seemingly work like `//[x86]
needs-llvm-components: x86` or `//[nll_beyond]should-fail` do not get
evaluated properly.
Herein we verify that all of the tests that specify a `--target`
compile-flag, are also annotated with the minimal set of required llvm
components necessary to run that test.
bors [Thu, 24 Jun 2021 20:01:39 +0000 (20:01 +0000)]
Auto merge of #85651 - dns2utf8:rustdoc_flexbox, r=GuillaumeGomez
rustdoc: staggered layout for module contents on mobile
This PR adds the container `<item-table>` with its two children `<item-left>` and `<item-right>`.
It uses grid-layout on desktop and flexbox on mobile to make better use of the available space.
Additionally it allows to share parts of the CSS with the search function.
bors [Thu, 24 Jun 2021 17:37:29 +0000 (17:37 +0000)]
Auto merge of #86467 - ChrisDenton:win-env-clear, r=JohnTitor
Windows: Fix `Command::env_clear` so it works if no variables are set
Previously, it would error unless at least one new environment variable was added. The missing null presumably meant that Windows was reading random memory in that case.
See: [CreateProcessW](https://docs.microsoft.com/en-us/windows/win32/api/processthreadsapi/nf-processthreadsapi-createprocessw) (scroll down to `lpEnvironment`). Essentially the environment block is a null terminated list of null terminated strings and an empty list is `\0\0` and not `\0`.
EDIT: Oh, [CreateEnvironmentBlock](https://docs.microsoft.com/en-gb/windows/win32/api/userenv/nf-userenv-createenvironmentblock) states this much more explicitly.
bors [Thu, 24 Jun 2021 14:56:28 +0000 (14:56 +0000)]
Auto merge of #85427 - ehuss:fix-use-placement, r=jackh726
Fix use placement for suggestions near main.
This fixes an edge case for the suggestion to add a `use`. When running with `--test`, the `main` function will be annotated with an `#[allow(dead_code)]` attribute. The `UsePlacementFinder` would end up using the dummy span of that synthetic attribute. If there are top-level inner attributes, this would place the `use` in the wrong position. The solution here is to ignore attributes with dummy spans.
In the process of working on this, I discovered that the `use_suggestion_placement` test was broken. `UsePlacementFinder` is unaware of active attributes. Attributes like `#[derive]` don't exist in the AST since they are removed. Fixing that is difficult, since the AST does not retain enough information. I considered trying to place the `use` towards the top of the module after any `extern crate` items, but I couldn't find a way to get a span for the start of a module block (the `mod` span starts at the `mod` keyword, and it seems tricky to find the spot just after the opening bracket and past inner attributes). For now, I just put some comments about the issue. This appears to have been a known issue in #44215 where the test for it was introduced, and the fix seemed to be deferred to later.
bors [Thu, 24 Jun 2021 07:29:59 +0000 (07:29 +0000)]
Auto merge of #86279 - JohnTitor:transparent-zero-size-fields, r=nikomatsakis
Permit zero non-zero-field on transparent types
Fixes #77841
This makes the transparent fields meet the below:
> * A `repr(transparent)` type `T` must meet the following rules:
> * It may have any number of 1-ZST fields
> * In addition, it may have at most one other field of type U
Yuki Okushi [Thu, 24 Jun 2021 04:47:37 +0000 (13:47 +0900)]
Rollup merge of #86560 - ehuss:update-cargo, r=ehuss
Update cargo
This also updates `opener` used in bootstrap (to try to keep dependencies unified).
18 commits in 44456677b5d1d82fe981c955dc5c67734b31f340..9233aa06c801801cff75df65df718d70905a235e
2021-06-12 18:00:01 +0000 to 2021-06-22 21:32:55 +0000
- Detect incorrectly named cargo.toml (rust-lang/cargo#9607)
- Unify weak and namespaced features. (rust-lang/cargo#9574)
- Change `rustc-cdylib-link-arg` error to a warning. (rust-lang/cargo#9563)
- Updates to future-incompatible reporting. (rust-lang/cargo#9606)
- Add a compatibility notice for diesel and the new resolver. (rust-lang/cargo#9602)
- Don't allow config env to modify vars set by cargo (rust-lang/cargo#9579)
- Disambiguate is_symlink. (rust-lang/cargo#9604)
- Update opener requirement from 0.4 to 0.5 (rust-lang/cargo#9583)
- Avoid quadratic complexity when splitting output into lines (rust-lang/cargo#9586)
- Bump to 0.56.0, update changelog (rust-lang/cargo#9597)
- Fix dep-info files including non-local build script paths. (rust-lang/cargo#9596)
- Relax doc collision error. (rust-lang/cargo#9595)
- Handle "jobs = 0" case in cargo config files (rust-lang/cargo#9584)
- Enhancements to testsuite error output. (rust-lang/cargo#9589)
- Fix typo (rust-lang/cargo#9590)
- Enable support for fix --edition for 2021. (rust-lang/cargo#9588)
- Add more details for installing git repository errors (rust-lang/cargo#9582)
- More information for links conflicting (rust-lang/cargo#9568)
Yuki Okushi [Thu, 24 Jun 2021 04:47:35 +0000 (13:47 +0900)]
Rollup merge of #86533 - inquisitivecrystal:lower-case-error-explain, r=petrochenkov
Support lowercase error codes in `--explain`
This enables `rustc --explain` to accept a lowercase error code. Thus, for instance, `rustc --explain e0573` would be valid after this change, where before a user would have needed to do `rustc --explain E0573`. Although the upper case form of an error code is canonical, the user may prefer the easier-to-type lowercase form, and there's nothing to be gained by forcing them to type the upper case version.
Yuki Okushi [Thu, 24 Jun 2021 04:47:34 +0000 (13:47 +0900)]
Rollup merge of #86415 - Kmeakin:iterator-associativity-docs, r=dtolnay
Document associativity of iterator folds.
Document the associativity of `Iterator::fold` and
`DoubleEndedIterator::rfold` and add examples demonstrating this.
Add links to direct users to the fold of the opposite associativity.
Yuki Okushi [Thu, 24 Jun 2021 04:47:26 +0000 (13:47 +0900)]
Rollup merge of #86137 - GuillaumeGomez:error-code-cleanup, r=Mark-Simulacrum
Error code cleanup and enforce checks
Fixes #86097.
It now checks if an error code is unused, and if so, will report an error if the error code wasn't commented out in the `error_codes.rs` file. It also checks that the constant used in the tidy check is up-to-date.
bors [Wed, 23 Jun 2021 21:35:46 +0000 (21:35 +0000)]
Auto merge of #86138 - FabianWolff:issue-85871, r=nikomatsakis
Check whether the closure's owner is an ADT in thir-unsafeck
This pull request fixes #85871. The code in `rustc_mir_build/src/check_unsafety.rs` incorrectly assumes that a closure's owner always has a body, but only functions, closures, and constants have bodies, whereas a closure can also appear inside a struct or enum:
```rust
struct S {
arr: [(); match || 1 { _ => 42 }]
}
enum E {
A([(); { || 1; 42 }])
}
```
This pull request fixes the resulting ICE by checking whether the closure's owner is an ADT and only deferring to `thir_check_unsafety(owner)` if it isn't.
bors [Wed, 23 Jun 2021 08:45:17 +0000 (08:45 +0000)]
Auto merge of #86548 - GuillaumeGomez:fix-crate-filter-search-reset, r=jsha
Fix crate filter search reset
I found a fun bug when using rustdoc recently: I made a search, cut the search input content, changed the crate filter, pasted back the input content. To my surprise, the crate filter wasn't applied. It's because that our search input was empty when receiving the `<select>` "onchange" event. To fix this issue, I reset the `currentResults` variable to `null`.
It's using the first commit from #86542 so it needs to wait for it before getting merged.
bors [Wed, 23 Jun 2021 03:16:04 +0000 (03:16 +0000)]
Auto merge of #86386 - inquisitivecrystal:better-errors-for-display-traits-v3, r=estebank
Better errors for Debug and Display traits
Currently, if someone tries to pass value that does not implement `Debug` or `Display` to a formatting macro, they get a very verbose and confusing error message. This PR changes the error messages for missing `Debug` and `Display` impls to be less overwhelming in this case, as suggested by #85844. I was a little less aggressive in changing the error message than that issue proposed. Still, this implementation would be enough to reduce the number of messages to be much more manageable.
After this PR, information on the cause of an error involving a `Debug` or `Display` implementation would suppressed if the requirement originated within a standard library macro. My reasoning was that errors originating from within a macro are confusing when they mention details that the programmer can't see, and this is particularly problematic for `Debug` and `Display`, which are most often used via macros. It is possible that either a broader or a narrower criterion would be better. I'm quite open to any feedback.
bors [Tue, 22 Jun 2021 23:58:03 +0000 (23:58 +0000)]
Auto merge of #86559 - Dylan-DPC:rollup-aixg3q5, r=Dylan-DPC
Rollup of 6 pull requests
Successful merges:
- #86223 (Specify the kind of the item for E0121)
- #86521 (Add comments around code where ordering is important due for panic-safety)
- #86523 (Improvements to intra-doc link macro disambiguators)
- #86542 (Line numbers aligned with content)
- #86549 (Add destructuring example of E0508)
- #86557 (Update books)
Dylan DPC [Tue, 22 Jun 2021 22:20:24 +0000 (00:20 +0200)]
Rollup merge of #86557 - ehuss:update-books, r=ehuss
Update books
## nomicon
10 commits in 55de6fa3c1f331774da19472c9ee57d2ae9eb039..b9ca313e687c991223e23e5520529815dc281205
2021-05-12 00:31:01 +0900 to 2021-06-22 12:02:20 -0400
- The #[repr(C)] attribute on the callback example is not necessary, since the type is not used in C.
- Reorganize some chapters (rust-lang-nursery/nomicon#282)
- Mention "extern types" on the opaque structs section (rust-lang-nursery/nomicon#273)
- Clarify the conditions on the aliasing section (rust-lang-nursery/nomicon#272)
- Upgrade to edition 2018 (rust-lang-nursery/nomicon#280)
- Update some wording making reference to issues/RFCs (rust-lang-nursery/nomicon#271)
- Some improvements on the "subtyping" chapter (rust-lang-nursery/nomicon#278)
- Clarify casting between the same size fixed ints (rust-lang-nursery/nomicon#277)
- Add a link to show why unused lifetimes on structs are forbidden (rust-lang-nursery/nomicon#276)
- Fix small typo in the Drop Check chapter (rust-lang-nursery/nomicon#275)
## reference
8 commits in 8f598e2af6c25b4a7ee88ef6a8196d9b8ea50ca8..d9699fa8f3186440fdaadd703d63d8d42322c176
2021-06-01 19:00:46 +0100 to 2021-06-21 12:23:10 -0700
- Make explicit reference to scrutinee expression in grammar snippet (rust-lang-nursery/reference#1044)
- Document sub-namespaces. (rust-lang-nursery/reference#1043)
- Default all examples to 2018 edition. (rust-lang-nursery/reference#1041)
- Minor update to macros. (rust-lang-nursery/reference#1048)
- (rust-lang-nursery/reference#1049)
- Add a note why the same size int casting is a no-op (rust-lang-nursery/reference#1046)
- Add notes on `#[target_feature]` for wasm (rust-lang-nursery/reference#1047)
- Make statement about variable visibility more precise (rust-lang-nursery/reference#1045)
## rustc-dev-guide
8 commits in c8da5bfd1c7c71d90ef1646f5e0a9f6609d5c78a..fe34beddb41dea5cb891032512a8d5b842b99696
2021-06-04 09:08:56 +0200 to 2021-06-21 21:50:12 +0200
- Update "Inference variables" section (rust-lang/rustc-dev-guide#1145)
- Document how to run unit tests (rust-lang/rustc-dev-guide#1141)
- We stopped using allow_internal_unstable a while ago (rust-lang/rustc-dev-guide#1142)
- Change the feature used as an example of stabilizing lib features (rust-lang/rustc-dev-guide#1143)
- We use HIR to do type inference, trait solving and type checking (rust-lang/rustc-dev-guide#1139)
- Add suggested settings note for coc (rust-lang/rustc-dev-guide#1144)
- move 7/8 to prose
- Add a section on keeping things up to date in the git section
Dylan DPC [Tue, 22 Jun 2021 22:20:22 +0000 (00:20 +0200)]
Rollup merge of #86542 - GuillaumeGomez:line-numbers-aligned-with-content, r=jyn514
Line numbers aligned with content
We had the issue a few times in the past where the source code pages' content wasn't aligned with the line numbers but completely below. This test will prevent this change to go unnoticed.
The first commit comes from https://github.com/rust-lang/rust/pull/86541 so it needs it to be merged first.
Dylan DPC [Tue, 22 Jun 2021 22:20:21 +0000 (00:20 +0200)]
Rollup merge of #86523 - LeSeulArtichaut:macros-disambiguators, r=jyn514
Improvements to intra-doc link macro disambiguators
A few small improvements around macro disambiguators:
- display the link text as it was entered: previously `[macro!()]` would be displayed without the parantheses (fixes #86309)
- support `!{}` and `![]` as macro disambiguators (fixes #86310)
Dylan DPC [Tue, 22 Jun 2021 22:20:20 +0000 (00:20 +0200)]
Rollup merge of #86521 - the8472:add-footgun-comments, r=RalfJung
Add comments around code where ordering is important due for panic-safety
Iterators contain arbitrary code which may panic. Unsafe code has to be
careful to do its state updates at the right point between calls that may panic.
As requested in https://github.com/rust-lang/rust/pull/86452#discussion_r655153948
bors [Tue, 22 Jun 2021 17:34:55 +0000 (17:34 +0000)]
Auto merge of #86045 - jsgf:fix-emit-path-hashing, r=bjorn3
Fix emit path hashing
With `--emit KIND=PATH`, the PATH should not affect hashes used for dependency tracking. It does not with other ways of specifying output paths (`-o` or `--out-dir`).
Also updates `rustc -Zls` to print more info about crates, which is used here to implement a `run-make` test.
It seems there was already a test explicitly checking that `OutputTypes` hash *is* affected by the path. I think this behaviour is wrong, so I updated the test.
The8472 [Mon, 21 Jun 2021 19:29:43 +0000 (21:29 +0200)]
Add comments around code where ordering is important due for panic-safety
Iterators contain arbitrary code which may panic. Unsafe code has to be
careful to do its state updates at the right point between calls
that may panic.
bors [Tue, 22 Jun 2021 14:53:58 +0000 (14:53 +0000)]
Auto merge of #86368 - michaelwoerister:lexing-ice, r=davidtwco
Disambiguate between SourceFiles from different crates even if they have the same path
This PR fixes an ICE that can occur when the compiler encounters a source file that is part of both the local crate and an upstream crate:
1. While importing source files from an upstream crate the compiler creates a `SourceFile` entry for `foo.rs` in the `SourceMap`. Since this is an imported source file its `src` field is `None`.
2. At a later point the parser encounters `foo.rs` again. It tells the `SourceMap` to load the file but because we already have an entry for `foo.rs` the `SourceMap` will return the existing version with `src == None`.
3. The parser proceeds under the assumption that `src.is_some()` and panics when actually trying to use the file's contents.
This PR fixes the issue by adding the source file's associated `CrateNum` to the `SourceMap`'s interning key. As a consequence the two instances of the file will each have a separate entry in the `SourceMap`. They just happen to share the same file path. This approach seemed less problematic to me than trying to mutate the `SourceFile` after it had already been created.
Another, more involved, approach might be to merge the `src` and the `external_src` field.
Yuki Okushi [Tue, 22 Jun 2021 11:01:06 +0000 (20:01 +0900)]
Rollup merge of #86537 - inquisitivecrystal:mark-edition-tests-check-pass, r=JohnTitor
Mark some edition tests as check-pass
## Overview
This helps with #62277. In short, there are some tests that were marked as `build-pass` when it was unclear whether `check-pass` might be more appropriate. This PR marks some of those tests as `compile-pass`, in addition to making some incidental formatting improvements.
## A brief explanation of why this is correct
These tests fall into a few buckets.
These test a lint for a keyword added in a new edition and the corresponding changes in keyword rules.
`src/test/ui/editions/edition-feature-ok.rs`
This checks that a feature related to an edition transition is valid.
`src/test/ui/editions/edition-imports-virtual-2015-ambiguity.rs`
This checks that imports between editions work correctly.
`src/test/ui/editions/edition-keywords-2015-2015-expansion.rs`
`src/test/ui/editions/edition-keywords-2018-2015-expansion.rs`
This checks the interaction between a change in keyword status over editions and macros.
All of the things being tested come before linking and codegen, so it is safe to use `check-pass` for them.
Yuki Okushi [Tue, 22 Jun 2021 11:01:05 +0000 (20:01 +0900)]
Rollup merge of #86517 - camsteffen:unused-unsafe-async, r=LeSeulArtichaut
Fix `unused_unsafe` around `await`
Enables `unused_unsafe` lint for `unsafe { future.await }`.
The existing test for this is `unsafe { println!() }`, so I assume that `println!` used to contain compiler-generated unsafe but this is no longer true, and so the existing test is broken. I replaced the test with `unsafe { ...await }`. I believe `await` is currently the only instance of compiler-generated unsafe.
Reverts some parts of #85421, but the issue predates that PR.
Yuki Okushi [Tue, 22 Jun 2021 11:01:04 +0000 (20:01 +0900)]
Rollup merge of #86501 - jyn514:doctest-cleanup, r=CraftSpider
Cleanup handling of `crate_name` for doctests
- Remove unnecessary reallocation
- Remove unnecessary messing around with `queries` for the crate name; it's simpler and faster to go through the TyCtxt instead
- Rename `cratename` -> `crate_name` for consistency with the rest of the compiler
Yuki Okushi [Tue, 22 Jun 2021 11:01:01 +0000 (20:01 +0900)]
Rollup merge of #86402 - tspiteri:source-woff2, r=jsha
rustdoc: add optional woff2 versions of Source Serif and Source Code
This provides woff2 versions of Source Serif and Source Code similar to how #82545 provides woff2 versions of Fira Sans. The total byte count for the six files (three for each font family) is reduced by 25% from 476 KiB to 358 KiB.
bors [Tue, 22 Jun 2021 09:30:15 +0000 (09:30 +0000)]
Auto merge of #84910 - eopb:stabilize_int_error_matching, r=yaahc
stabilize `int_error_matching`
closes #22639
> It has been over half a year since https://github.com/rust-lang/rust/pull/77640#pullrequestreview-511263516, and the indexing question is rejected in https://github.com/rust-lang/rust/pull/79728#pullrequestreview-633030341, so I guess we can submit another stabilization attempt? 😉
_Originally posted by `@kennytm` in https://github.com/rust-lang/rust/issues/22639#issuecomment-831738266_
bors [Tue, 22 Jun 2021 07:01:54 +0000 (07:01 +0000)]
Auto merge of #85707 - jam1garner:future_prelude_collision_lint, r=nikomatsakis
Add `future_prelude_collision` lint
Implements #84594. (RFC rust-lang/rfcs#3114 ([rendered](https://github.com/rust-lang/rfcs/blob/master/text/3114-prelude-2021.md))) Not entirely complete but wanted to have my progress decently available while I finish off the last little bits.
Things left to implement:
* [x] UI tests for lints
* [x] Only emit lint for 2015 and 2018 editions
* [ ] Lint name/message bikeshedding
* [x] Implement for `FromIterator` (from best I can tell, the current approach as mentioned from [this comment](https://github.com/rust-lang/rust/issues/84594#issuecomment-847288288) won't work due to `FromIterator` instances not using dot-call syntax, but if I'm correct about this then that would also need to be fixed for `TryFrom`/`TryInto`)*
* [x] Add to `rust-2021-migration` group? (See #85512) (added to `rust-2021-compatibility` group)
* [ ] Link to edition guide in lint docs
*edit: looked into it, `lookup_method` will also not be hit for `TryFrom`/`TryInto` for non-dotcall syntax. If anyone who is more familiar with typecheck knows the equivalent for looking up associated functions, feel free to chime in.
bors [Tue, 22 Jun 2021 01:14:31 +0000 (01:14 +0000)]
Auto merge of #86527 - JohnTitor:rollup-cbu78g4, r=JohnTitor
Rollup of 11 pull requests
Successful merges:
- #85054 (Revert SGX inline asm syntax)
- #85182 (Move `available_concurrency` implementation to `sys`)
- #86037 (Add `io::Cursor::{remaining, remaining_slice, is_empty}`)
- #86114 (Reopen #79692 (Format symbols under shared frames))
- #86297 (Allow to pass arguments to rustdoc-gui tool)
- #86334 (Resolve type aliases to the type they point to in intra-doc links)
- #86367 (Fix comment about rustc_inherit_overflow_checks in abs().)
- #86381 (Add regression test for issue #39161)
- #86387 (Remove `#[allow(unused_lifetimes)]` which is now unnecessary)
- #86398 (Add regression test for issue #54685)
- #86493 (Say "this enum variant takes"/"this struct takes" instead of "this function takes")
Yuki Okushi [Mon, 21 Jun 2021 22:37:56 +0000 (07:37 +0900)]
Rollup merge of #86493 - Smittyvb:ctor-typeck-error, r=davidtwco
Say "this enum variant takes"/"this struct takes" instead of "this function takes"
This makes error messages for functions with incorrect argument counts adapt if they refer to a struct or enum variant:
```
error[E0061]: this enum variant takes 1 argument but 0 arguments were supplied
--> $DIR/struct-enum-wrong-args.rs:7:13
|
LL | let _ = Ok();
| ^^-- supplied 0 arguments
| |
| expected 1 argument
error[E0061]: this struct takes 1 argument but 0 arguments were supplied
--> $DIR/struct-enum-wrong-args.rs:8:13
|
LL | let _ = Wrapper();
| ^^^^^^^-- supplied 0 arguments
| |
| expected 1 argument
```
Yuki Okushi [Mon, 21 Jun 2021 22:37:54 +0000 (07:37 +0900)]
Rollup merge of #86398 - yerke:add-test-for-issue-54685, r=Mark-Simulacrum
Add regression test for issue #54685
Closes #54685
Took the test from #54685 and modified it a bit to use assertion. Made sure that the updated test catches the original issue on 1.50 by running on Compiler Explorer (https://godbolt.org/z/E64onYeT5).
I came across an inconvenience when answering the following [Stack Overflow](https://stackoverflow.com/questions/67831170) question.
To get the remaining slice you have to call `buff.fill_buf().unwrap()`. Which in my opinion doesn't really tell you what is returned (in the context of Cursor). To improve readability and convenience when using Cursor i propose adding the method `remaining`.
The next thing i found inconvenient (unnecessary long) was detecting if the cursor reached the end. There are a few ways this can be achieved right now:
- `buff.fill_buf().unwrap().is_empty()`
- `buff.position() >= buff.get_ref().len()`
- `buff.bytes().next().is_none()`
Which all seem a bit unintuitive, hidden in trait documentations or just a bit long for such a simple task.
Therefor i propose another method called `is_empty`, maybe with another name, since this one may leave room for interpretation on what really is empty (the underlying slice, the remaining slice or maybe the position).
Since it seemed easier to create this PR instead of an RFC i did that, if an RFC is wanted, i can close this PR and write an RFC first.
Yuki Okushi [Mon, 21 Jun 2021 22:37:46 +0000 (07:37 +0900)]
Rollup merge of #85182 - CDirkx:available_concurrency, r=JohnTitor
Move `available_concurrency` implementation to `sys`
This splits out the platform-specific implementation of `available_concurrency` to the corresponding platforms under `sys`. No changes are made to the implementation.
Tidy didn't lint against this code being originally added outside of `sys` because of a bug (see #84677), this PR also reverts the exclusion that was introduced in that bugfix.
bors [Mon, 21 Jun 2021 22:24:13 +0000 (22:24 +0000)]
Auto merge of #86383 - shamatar:slice_len_lowering, r=bjorn3
Add MIR pass to lower call to `core::slice::len` into `Len` operand
During some larger experiment with range analysis I've found that code like `let l = slice.len()` produces different MIR then one found in bound checks. This optimization pass replaces terminators that are calls to `core::slice::len` with just a MIR operand and Goto terminator.
It uses some heuristics to remove the outer borrow that is made to call `core::slice::len`, but I assume it can be eliminated, just didn't find how.
Would like to express my gratitude to `@oli-obk` who helped me a lot on Zullip
projects / rust.git / log