Commit Graph

151141 Commits

Author SHA1 Message Date
Guillaume Gomez
58be639142
Rollup merge of #86957 - jhpratt:update-mailmap, r=jyn514
Update .mailmap file
2021-07-08 18:30:40 +02:00
Guillaume Gomez
e30eb4d1a2
Rollup merge of #86913 - Stupremee:document-rustdoc-private-items, r=jyn514
Document rustdoc with `--document-private-items`

The `tool_doc` macro introduced in #86737 did not use `false` as the default value for `binary` when it is not provided, so the `if` is not even expanded and thus the argument is never provided if the `binary` argument isn't.

Resolves #86900

r? ```@Mark-Simulacrum```
2021-07-08 18:30:39 +02:00
Guillaume Gomez
46314f7d85
Rollup merge of #86903 - GuillaumeGomez:small-header-display, r=Nemo157
Fix small headers display

You can see it on the `IoSlice` or on the `ErrorKind` pages.

Before:

![Screenshot from 2021-07-06 15-26-33](https://user-images.githubusercontent.com/3050060/124610344-b50a8100-de70-11eb-8ab4-ac5de8adf18f.png)
![Screenshot from 2021-07-08 17-51-43](https://user-images.githubusercontent.com/3050060/124953436-7235de00-e015-11eb-9f99-b361c7eb41a9.png)

After:

![Screenshot from 2021-07-08 17-48-42](https://user-images.githubusercontent.com/3050060/124953042-12d7ce00-e015-11eb-8132-1ae4552dd969.png)
![Screenshot from 2021-07-08 17-48-47](https://user-images.githubusercontent.com/3050060/124953052-13706480-e015-11eb-89f8-dab96c2f0f63.png)

r? `@Nemo157`
2021-07-08 18:30:38 +02:00
Guillaume Gomez
d85718ad01
Rollup merge of #86838 - lambinoo:I-69630-rust_const_unstable_check_const, r=oli-obk
Checking that function is const if marked with rustc_const_unstable

Fixes #69630

This one is still missing tests to check the behavior but I checked by hand and it seemed to work.
I would not mind some direction for writing those unit tests!
2021-07-08 18:30:34 +02:00
Guillaume Gomez
ff4bf73a42
Rollup merge of #86789 - janikrabe:btreeset-drainfilter-doc, r=kennytm
Update BTreeSet::drain_filter documentation

This commit makes the documentation of `BTreeSet::drain_filter` more
consistent with that of `BTreeMap::drain_filter` after the changes in
f0b8166870.

In particular, this explicitly documents the iteration order.
2021-07-08 18:30:34 +02:00
Guillaume Gomez
d12b16887b
Rollup merge of #86726 - sexxi-goose:use-diagnostic-item-for-rfc2229-migration, r=nikomatsakis
Use diagnostic items instead of lang items for rfc2229 migrations

This PR removes the `Send`, `UnwindSafe` and `RefUnwindSafe` lang items introduced in https://github.com/rust-lang/rust/pull/84730, and uses diagnostic items instead to check for `Send`, `UnwindSafe` and `RefUnwindSafe` traits for RFC2229 migrations.

r? ```@nikomatsakis```
2021-07-08 18:30:33 +02:00
Guillaume Gomez
d9297aea10
Rollup merge of #84961 - GuillaumeGomez:rework-session-globals, r=oli-obk
Rework SESSION_GLOBALS API

Fixes #84954.

<s>Needs #84953 to be merged first (I cherry-picked its commits to have CI pass).</s> (done)

r? ``@Aaron1011``
2021-07-08 18:30:32 +02:00
Guillaume Gomez
1f84bffdf0 Fix display of small-section-header elements 2021-07-08 17:49:06 +02:00
Guillaume Gomez
d891c8cd54 Update to last upstream version 2021-07-08 17:14:28 +02:00
Guillaume Gomez
a2654fb64c Rework SESSION_GLOBALS API to prevent overwriting it 2021-07-08 16:16:28 +02:00
bors
0deb536ff9 Auto merge of #85363 - EFanZh:gdb-pretty-print-slices, r=michaelwoerister
Support pretty printing slices using GDB

Support pretty printing `&[T]`, `&mut [T]` and `&mut str` types using GDB.

Support pretty printing `&mut [T]` and `&mut str` types using LLDB.

Fixes #85219.
2021-07-08 12:25:47 +00:00
bors
0cd0709f19 Auto merge of #86823 - the8472:opt-chunk-tra, r=kennytm
Optimize unchecked indexing into chunks and chunks_mut

Fixes #53340

```
# BEFORE

$ rustc +nightly -Copt-level=3 -Ccodegen-units=1 -Clto=fat chunks.rs
$ perf stat ./chunks

 Performance counter stats for './chunks':

          3,177.03 msec task-clock                #    1.000 CPUs utilized
                 4      context-switches          #    0.001 K/sec
                 0      cpu-migrations            #    0.000 K/sec
           984,006      page-faults               #    0.310 M/sec
    13,092,199,322      cycles                    #    4.121 GHz                      (83.29%)
       384,543,475      stalled-cycles-frontend   #    2.94% frontend cycles idle     (83.35%)
     7,414,280,722      stalled-cycles-backend    #   56.63% backend cycles idle      (83.38%)
    50,493,980,662      instructions              #    3.86  insn per cycle
                                                  #    0.15  stalled cycles per insn  (83.29%)
     6,625,375,297      branches                  # 2085.396 M/sec                    (83.38%)
         3,087,652      branch-misses             #    0.05% of all branches          (83.31%)

       3.178079469 seconds time elapsed

       2.327156000 seconds user
       0.762041000 seconds sys

# AFTER

$ ./build/x86_64-unknown-linux-gnu/stage1/bin/rustc -Copt-level=3 -Ccodegen-units=1 -Clto=fat chunks.rs
$ perf stat ./chunks

 Performance counter stats for './chunks':

          2,705.76 msec task-clock                #    1.000 CPUs utilized
                 4      context-switches          #    0.001 K/sec
                 0      cpu-migrations            #    0.000 K/sec
           984,005      page-faults               #    0.364 M/sec
    11,156,763,039      cycles                    #    4.123 GHz                      (83.26%)
       342,198,882      stalled-cycles-frontend   #    3.07% frontend cycles idle     (83.37%)
     6,486,263,637      stalled-cycles-backend    #   58.14% backend cycles idle      (83.37%)
    40,553,476,617      instructions              #    3.63  insn per cycle
                                                  #    0.16  stalled cycles per insn  (83.37%)
     6,668,429,113      branches                  # 2464.532 M/sec                    (83.37%)
         3,099,636      branch-misses             #    0.05% of all branches          (83.26%)

       2.706725288 seconds time elapsed

       1.782083000 seconds user
       0.848424000 seconds sys
```
2021-07-08 09:44:52 +00:00
bors
2daa26b7ca Auto merge of #86949 - RalfJung:miri, r=RalfJung
update Miri

Fixes https://github.com/rust-lang/rust/issues/86923
Cc `@rust-lang/miri` r? `@ghost`
2021-07-08 06:46:41 +00:00
Lamb
07f903e0e0 fn must be const if marked with stability attribut
remove trailing newline

fix: test with attribute but missing const

Update compiler/rustc_passes/src/stability.rs

Co-authored-by: Léo Lanteri Thauvin <leseulartichaut@gmail.com>

Add test for extern functions

fix: using span_help instead of span_suggestion

add test for some ABIs + fmt fix

Update compiler/rustc_passes/src/stability.rs

Co-authored-by: Léo Lanteri Thauvin <leseulartichaut@gmail.com>

Refractor and add test for `impl const`

Add test to make sure no output + cleanup condition

-----------------------------

remove stdcall test, failing CI test

C abi is already tested in this, so it is not that useful to test another one.
The tested code is blind to which specific ABI for now, as long as it's not an intrinsic one
2021-07-08 07:52:05 +02:00
bors
ac8c3bfffb Auto merge of #86966 - JohnTitor:rollup-uiqj2vc, r=JohnTitor
Rollup of 9 pull requests

Successful merges:

 - #86639 (Support lint tool names in rustc command line options)
 - #86812 (Recover from `&dyn mut ...` parse errors)
 - #86917 (Add doc comment for `impl From<LayoutError> for TryReserveError`)
 - #86925 (Add self to mailmap)
 - #86927 (Sync rustc_codegen_cranelift)
 - #86932 (Fix ICE when misplaced visibility cannot be properly parsed)
 - #86933 (Clean up rustdoc static files)
 - #86955 (Fix typo in `ops::Drop` docs)
 - #86956 (Revert "Add "every" as a doc alias for "all".")

Failed merges:

r? `@ghost`
`@rustbot` modify labels: rollup
2021-07-08 04:05:41 +00:00
Yuki Okushi
01474ad92c
Rollup merge of #86956 - cuviper:unalias-every, r=m-ou-se
Revert "Add "every" as a doc alias for "all"."

This reverts commit 35450365ac (#81697) for "every" and closes #86554 in kind for "some".

The new [doc alias policy](https://std-dev-guide.rust-lang.org/documentation/doc-alias-policy.html) is that we don't want language-specific aliases like these JavaScript names, and we especially don't want to conflict with real names. While "every" is okay in the latter regard, its natural pair "some" makes a doc-search collision with `Option::Some`.

r? ```@m-ou-se```
2021-07-08 10:44:37 +09:00
Yuki Okushi
0f37050b74
Rollup merge of #86955 - Swordelf2:patch-1, r=cuviper
Fix typo in `ops::Drop` docs
2021-07-08 10:44:36 +09:00
Yuki Okushi
59b4f88af1
Rollup merge of #86933 - GuillaumeGomez:cleanup-rustdoc-static-files, r=Manishearth
Clean up rustdoc static files

The `html/static` of rustdoc was starting to be quite a mess... So I moved files in sub-folders to make it easier to follow. Here what remains in `html/static` folder:

```
$ ls
COPYRIGHT.txt  css  fonts  images  js  LICENSE-APACHE.txt  LICENSE-MIT.txt
```

cc ```@jyn514```
r? ```@Manishearth```
2021-07-08 10:44:35 +09:00
Yuki Okushi
463301aa5a
Rollup merge of #86932 - rylev:fix-ice-86895, r=estebank
Fix ICE when misplaced visibility cannot be properly parsed

Fixes #86895

The issue was that a failure to parse the visibility was causing the original error to be dropped before being emitted.

The resulting error isn't quite as nice as when the visibility is parsed properly, but I'm not sure which error to prioritize here. Displaying both errors might be too confusing.

r? ```@estebank```
2021-07-08 10:44:34 +09:00
Yuki Okushi
89638a1ddc
Rollup merge of #86927 - bjorn3:sync_cg_clif-2021-07-07, r=bjorn3
Sync rustc_codegen_cranelift

The main hightlight this sync is basic support for AArch64. Most things should work on Linux, but there does seem to be an ABI incompatibility causing proc-macros to crash, see https://github.com/bjorn3/rustc_codegen_cranelift/issues/1184. Thanks to ```@afonso360``` for implementing all Cranelift features that were necessary to compile for AArch64 using cg_clif. Also thanks to ```@shamatar``` for implementing the `llvm.x86.addcarry.64` and `llvm.x86.subborrow.64` llvm intrinsics used by num-bigint (https://github.com/bjorn3/rustc_codegen_cranelift/pull/1178) and ```@eggyal``` for implementing multi-threading support for the lazy jit mode. (https://github.com/bjorn3/rustc_codegen_cranelift/pull/1166)

r? ```@ghost```

```@rustbot``` label +A-codegen +A-cranelift +T-compiler
2021-07-08 10:44:33 +09:00
Yuki Okushi
fccf0c2f8c
Rollup merge of #86925 - inquisitivecrystal:mailmap, r=Mark-Simulacrum
Add self to mailmap

For personal reasons, I would currently prefer to be known by this name.
2021-07-08 10:44:32 +09:00
Yuki Okushi
a57a2e991d
Rollup merge of #86917 - notriddle:notriddle/from-try-reserve-error, r=JohnTitor
Add doc comment for `impl From<LayoutError> for TryReserveError`
2021-07-08 10:44:31 +09:00
Yuki Okushi
165b520b89
Rollup merge of #86812 - FabianWolff:recover-dyn-mut, r=petrochenkov
Recover from `&dyn mut ...` parse errors

Consider this example:
```rust
fn main() {
    let r: &dyn mut Trait;
}
```
This currently leads to:
```
error: expected one of `!`, `(`, `;`, `=`, `?`, `for`, lifetime, or path, found keyword `mut`
 --> src/main.rs:2:17
  |
2 |     let r: &dyn mut Trait;
  |                 ^^^ expected one of 8 possible tokens

error: aborting due to previous error
```
However, especially for beginners, I think it is easy to get `&dyn mut` and `&mut dyn` confused. With my changes, I get a help message, and the parser even recovers:
```
error: `mut` must precede `dyn`
 --> test.rs:2:12
  |
2 |     let r: &dyn mut Trait;
  |            ^^^^^^^^ help: place `mut` before `dyn`: `&mut dyn`

error[E0405]: cannot find trait `Trait` in this scope
 --> test.rs:2:21
  |
2 |     let r: &dyn mut Trait;
  |                     ^^^^^ not found in this scope

error: aborting due to 2 previous errors
```
2021-07-08 10:44:30 +09:00
Yuki Okushi
c2d3f5f772
Rollup merge of #86639 - eholk:lint-tool, r=petrochenkov
Support lint tool names in rustc command line options

When rustc is running without a lint tool such as clippy enabled, options for lints such as `clippy::foo` are meant to be ignored. This was already working for those specified by attrs, such as `#![allow(clippy::foo)]`, but this did not work for command line arguments like `-A clippy::foo`. This PR fixes that issue.

Note that we discovered this issue while discussing https://github.com/rust-lang/cargo/issues/5034.

Fixes #86628.
2021-07-08 10:44:29 +09:00
Jacob Pratt
bd674b1e0b
Update .mailmap file 2021-07-07 16:32:04 -04:00
Josh Stone
ace3989d55 Revert "Add "every" as a doc alias for "all"."
This reverts commit 35450365ac.
2021-07-07 13:13:26 -07:00
Swordelf2
7677f5fe31
Fix typo in ops::Drop docs 2021-07-07 22:26:32 +03:00
bors
d2b04f075c Auto merge of #86105 - bjorn3:link_info_refactor, r=petrochenkov
Refactor the generation of the metadata for linking
2021-07-07 18:28:53 +00:00
Eric Holk
4a83a93e9a Cleanup: unify lint name checking
This change merges `check_lint_and_tool_name` into `check_lint_name` in
order to avoid having two very similar functions.

Also adds the `.stderr` file back for the test case, since apparently
it is still needed.
2021-07-07 10:50:50 -07:00
Eric Holk
5413d2e529 Fix test case
Previously this was using a `.stderr` file, but that does not seem to
work for all cases. This change uses `// error-pattern:` instead.
2021-07-07 10:28:35 -07:00
EFanZh
1b0998ca52 Ignore Windows debugger pretty-printing tests 2021-07-08 01:04:59 +08:00
Ralf Jung
381a9e5714 update Miri 2021-07-07 18:44:07 +02:00
Guillaume Gomez
e5c24ba400 Clean up rustdoc static files 2021-07-07 17:52:18 +02:00
Justus K
27b55e636f
Document rustdoc with --document-private-items 2021-07-07 16:52:30 +02:00
bjorn3
2977dff116 Remove a sorting operation from used_crates 2021-07-07 15:32:51 +02:00
Ryan Levick
04a9c10fc2 Fix ICE when misplaced visibility cannot be properly parsed 2021-07-07 15:02:20 +02:00
EFanZh
2b2bcf11ab Ignore Android debugger pretty-printing tests 2021-07-07 18:46:24 +08:00
bjorn3
00b2f56bc6 Add memchr to list of permitted cg_clif deps
Object started depending on it
2021-07-07 11:39:29 +02:00
bjorn3
d531f3d6ee Merge commit '3a31c6d8272c14388a34622193baf553636fe470' into sync_cg_clif-2021-07-07 2021-07-07 11:14:20 +02:00
bjorn3
3a31c6d827 Rustup to rustc 1.55.0-nightly (885399992 2021-07-06) 2021-07-07 11:08:52 +02:00
inquisitivecrystal
0db66e568c Add self to mailmap 2021-07-07 01:33:25 -07:00
bors
c5e344f774 Auto merge of #86920 - JohnTitor:rollup-buvzpkr, r=JohnTitor
Rollup of 8 pull requests

Successful merges:

 - #80918 (Add Integer::log variants)
 - #86717 (Rename some Rust 2021 lints to better names )
 - #86819 (Clean up rustdoc IDs)
 - #86880 (Test ManuallyDrop::clone_from.)
 - #86906 (Replace deprecated compare_and_swap and fix typo in core::sync::atomic::{fence, compiler_fence} docs)
 - #86907 (Migrate `cpu-usage-over-time.py` to Python 3)
 - #86916 (rewrote documentation for thread::yield_now())
 - #86919 (Update books)

Failed merges:

r? `@ghost`
`@rustbot` modify labels: rollup
2021-07-07 03:31:23 +00:00
Yuki Okushi
51968854f4
Rollup merge of #86919 - ehuss:update-books, r=ehuss
Update books

## nomicon

8 commits in b9ca313e687c991223e23e5520529815dc281205..7a13537f96af4b9b8e3ea296d6e5c3c7ab72ce9f
2021-06-22 12:02:20 -0400 to 2021-07-05 23:34:47 -0400
- Apply review comments
- Fix some style issues
- Move the list of coercions to the reference
- Add an example that shows the null-pointer opt does not happen
- Remove casting list from the nomicon (rust-lang-nursery/nomicon#287)
- Audit `ignore` annotations (rust-lang-nursery/nomicon#288)
- rename typo "lifetime" to "reference" (rust-lang-nursery/nomicon#286)
- Add an incomplete warning to the top page (rust-lang-nursery/nomicon#274)

## reference

7 commits in d9699fa8f3186440fdaadd703d63d8d42322c176..ab60513a3a5a0591e237fddff5d027a982648392
2021-06-21 12:23:10 -0700 to 2021-07-05 08:27:31 -0700
- fix grammar in Expressions (rust-lang-nursery/reference#1057)
- fix comment in function parameter drop scope example (rust-lang-nursery/reference#1056)
- fix typo in macro-ambiguity.md (rust-lang-nursery/reference#1058)
- Mention (negative) infinity values on float-to-int casting (rust-lang-nursery/reference#1054)
-  (rust-lang-nursery/reference#841)
- Missing TypeParamBounds in TypeAlias (rust-lang-nursery/reference#1036)
- Be more precise about array offset in type layouts (rust-lang-nursery/reference#1034)

## book

34 commits in 55a26488ddefc8433e73a2e8352d70f7a5c7fc2b..a90f07f1e9a7fc75dc9105a6c6f16d5c13edceb0
2021-05-09 12:03:18 -0500 to 2021-07-05 14:43:12 -0400
- Clarify ?Sized syntax. Fixes rust-lang/book#2422.
- Add some notes that macros are different than functions
- Break up a long sentence. Fixes rust-lang/book#2329.
- Further clarify and make consistent the reference to deref coercion
- Update ch04-03-slices.md
- add usage for `String` reference
- Update ch15-02-deref.md (rust-lang/book#2780)
- Remove claim about performance of i32
- Reword to avoid awkward pluralization
- Make the link to the reference relative
- Merge remote-tracking branch 'origin/pr/2753'
- Reword number of library crates a package contains (rust-lang/book#2750)
- Clarify explanation of why you can test private functions; add link
- Merge remote-tracking branch 'origin/pr/2743'
- Fix code hiding that I broke in eb60fedc9
- Link to the exact later section we're talking about
- improve cross-references for newtype pattern
- ch12-05, listing 12-20: Add missing "does not compile" warning (rust-lang/book#2731)
- cargo format
- Merge remote-tracking branch 'origin/pr/2724'
- Remove ordinal numbers and only refer to indexes to avoid confusion
- Let's mention the former and current authors of tlborm.
- Update tlborm link to point to Veykril's up-to-date version (rust-lang/book#2722)
- Merge remote-tracking branch 'origin/pr/2720'
- Describe the ferris pictures in the alt text
- Merge remote-tracking branch 'origin/pr/2707'
- Reword ... explanation to include the word deprecated, list that first
- Precise that the `...` inclusive range pattern has been replaces (rust-lang/book#2714)
-  (rust-lang/book#2696)
- fix typo: missing "type" after generic (rust-lang/book#2777)
-  (rust-lang/book#2709)
- Remove sentence about how Rust used to be
- Fix a potentially confusing statement about static lifetimes of static variables. (rust-lang/book#2692)
- Replace 'which'. (rust-lang/book#2663)

## rust-by-example

2 commits in 805e016c5792ad2adabb66e348233067d5ea9f10..028f93a61500fe8f746ee7cc6b204ea6c9f42935
2021-05-20 17:08:34 -0300 to 2021-07-06 06:28:53 -0300
- Fix a couple of typos in the `integration_testing.md` file (rust-lang/rust-by-example#1448)
- Fix Structures type list (rust-lang/rust-by-example#1446)

## rustc-dev-guide

13 commits in fe34beddb41dea5cb891032512a8d5b842b99696..60e282559104035985331645907c3d9f842312c5
2021-06-21 21:50:12 +0200 to 2021-07-05 11:21:03 -0400
- Fixed typos in inline code
- Document lang items (rust-lang/rustc-dev-guide#1119)
- More specifics on what future-incompatible lints are used for
- Fix line lens
- Update information on lints particularly on future-incompatible
- Update section of lint store
- Update around half of the January 2021 date references (rust-lang/rustc-dev-guide#1155)
- Create issues for many TODOs (rust-lang/rustc-dev-guide#1163)
- Links from rustc-dev-guide to std-dev-guide (rust-lang/rustc-dev-guide#1152)
- Document how to mark features as incomplete (rust-lang/rustc-dev-guide#1151)
- Remove requests or suggestions about rebase and fixup contradictory to rust-highfive bot comment (rust-lang/rustc-dev-guide#1111)
- Generate glossary table correctly (rust-lang/rustc-dev-guide#1146)
- Correct the wrong serial number (rust-lang/rustc-dev-guide#1147)

## edition-guide

3 commits in c74b2a0d6bf55774cf15d69f05dfe05408b8f81a..5d57b3832f8d308a9f478ce0a69799548f27ad4d
2021-06-14 10:48:27 -0700 to 2021-07-05 10:33:32 +0200
- Add more info for warnings promoted to errors (rust-lang-nursery/edition-guide#247)
- Create triagebot.toml
- Clarify snippets in 2021 panic docs. (rust-lang-nursery/edition-guide#245)

## embedded-book

1 commits in cbec77fbd8eea0c13e390dd9eded1ae200e811d1..506840eb73b0749336e1d5274e16d6393892ee82
2021-06-10 06:26:32 +0000 to 2021-06-24 00:01:32 +0000
- Update book to track quickstart changes  (rust-embedded/book#296)
2021-07-07 12:17:45 +09:00
Yuki Okushi
9aee3c2883
Rollup merge of #86916 - godmar:@godmar/thread-yield-documentation-fix, r=joshtriplett
rewrote documentation for thread::yield_now()

The old documentation suggested the use of yield_now for repeated
polling instead of discouraging it; it also made the false claim that
channels are implemented using yield_now. (They are not, except for
a corner case).
2021-07-07 12:17:44 +09:00
Yuki Okushi
7be29c1627
Rollup merge of #86907 - pietroalbini:ci-cpu-stats-python3, r=Mark-Simulacrum
Migrate `cpu-usage-over-time.py` to Python 3

The only change here is a fix for `sys.platform` on Linux. Python 3.3 changed the API to return `"linux"` instead of `"linux2"`/`"linux3"`, so this PR uses `.startswith("linux")` to make the code work on Python 3 without breaking Python 2.
2021-07-07 12:17:43 +09:00
Yuki Okushi
fe3d6a74d9
Rollup merge of #86906 - juniorbassani:update-sync-docs, r=yaahc
Replace deprecated compare_and_swap and fix typo in core::sync::atomic::{fence, compiler_fence} docs
2021-07-07 12:17:42 +09:00
Yuki Okushi
c630b6b0fc
Rollup merge of #86880 - m-ou-se:test-manuallydrop-clone-from, r=Mark-Simulacrum
Test ManuallyDrop::clone_from.

See #86288
2021-07-07 12:17:41 +09:00
Yuki Okushi
cbb40cd0f2
Rollup merge of #86819 - GuillaumeGomez:cleanup-rustdoc-ids, r=jyn514
Clean up rustdoc IDs

I cherry-picked the commit from https://github.com/rust-lang/rust/pull/86178. It adds missing rustdoc IDs (for the HTML) and remove unused ones.

cc `@camelid`

r? `@jyn514`
2021-07-07 12:17:40 +09:00
Yuki Okushi
7e95290caa
Rollup merge of #86717 - rylev:rename, r=nikomatsakis
Rename some Rust 2021 lints to better names

Based on conversation in https://github.com/rust-lang/rust/issues/85894.

Rename a bunch of Rust 2021 related lints:

Lints that are officially renamed because they are already in beta or stable:
* `disjoint_capture_migration` => `rust_2021_incompatible_closure_captures`
* `or_patterns_back_compat` => `rust_2021_incompatible_or_patterns`
* `non_fmt_panic` => `non_fmt_panics`

Lints that are renamed but don't require any back -compat work since they aren't yet in stable:
* `future_prelude_collision` => `rust_2021_prelude_collisions`
* `reserved_prefix` => `rust_2021_token_prefixes`

Lints that have been discussed but that I did not rename:
* ~`non_fmt_panic` and `bare_trait_object`: is making this plural worth the headache we might cause users?~
* `array_into_iter`: I'm unsure of a good name and whether bothering users with a name change is worth it.

r? `@nikomatsakis`
2021-07-07 12:17:39 +09:00
Yuki Okushi
9bbc470e97
Rollup merge of #80918 - yoshuawuyts:int-log2, r=m-ou-se
Add Integer::log variants

_This is another attempt at landing https://github.com/rust-lang/rust/pull/70835, which was approved by the libs team but failed on Android tests through Bors. The text copied here is from the original issue. The only change made so far is the addition of non-`checked_` variants of the log methods._

_Tracking issue: #70887_

---

This implements `{log,log2,log10}` methods for all integer types. The implementation was provided by `@substack` for use in the stdlib.

_Note: I'm not big on math, so this PR is a best effort written with limited knowledge. It's likely I'll be getting things wrong, but happy to learn and correct. Please bare with me._

## Motivation
Calculating the logarithm of a number is a generally useful operation. Currently the stdlib only provides implementations for floats, which means that if we want to calculate the logarithm for an integer we have to cast it to a float and then back to an int.

> would be nice if there was an integer log2 instead of having to either use the f32 version or leading_zeros() which i have to verify the results of every time to be sure

_— [`@substack,` 2020-03-08](https://twitter.com/substack/status/1236445105197727744)_

At higher numbers converting from an integer to a float we also risk overflows. This means that Rust currently only provides log operations for a limited set of integers.

The process of doing log operations by converting between floats and integers is also prone to rounding errors. In the following example we're trying to calculate `base10` for an integer. We might try and calculate the `base2` for the values, and attempt [a base swap](https://www.rapidtables.com/math/algebra/Logarithm.html#log-rules) to arrive at `base10`. However because we're performing intermediate rounding we arrive at the wrong result:

```rust
// log10(900) = ~2.95 = 2
dbg!(900f32.log10() as u64);

// log base change rule: logb(x) = logc(x) / logc(b)
// log2(900) / log2(10) = 9/3 = 3
dbg!((900f32.log2() as u64) / (10f32.log2() as u64));
```
_[playground](https://play.rust-lang.org/?version=stable&mode=debug&edition=2018&gist=6bd6c68b3539e400f9ca4fdc6fc2eed0)_

This is somewhat nuanced as a lot of the time it'll work well, but in real world code this could lead to some hard to track bugs. By providing correct log implementations directly on integers we can help prevent errors around this.

## Implementation notes

I checked whether LLVM intrinsics existed before implementing this, and none exist yet. ~~Also I couldn't really find a better way to write the `ilog` function. One option would be to make it a private method on the number, but I didn't see any precedent for that. I also didn't know where to best place the tests, so I added them to the bottom of the file. Even though they might seem like quite a lot they take no time to execute.~~

## References

- [Log rules](https://www.rapidtables.com/math/algebra/Logarithm.html#log-rules)
- [Rounding error playground](https://play.rust-lang.org/?version=stable&mode=debug&edition=2018&gist=6bd6c68b3539e400f9ca4fdc6fc2eed0)
- [substack's tweet asking about integer log2 in the stdlib](https://twitter.com/substack/status/1236445105197727744)
- [Integer Logarithm, A. Jaffer 2008](https://people.csail.mit.edu/jaffer/III/ilog.pdf)
2021-07-07 12:17:32 +09:00