Update books
## nomicon
3 commits in 2d66852a27c5d0ec50ae021820d1de22caa2b1bd..358e6a61d5f4f0496d0a81e70cdcd25d05307342
2021-10-07 19:00:37 +0900 to 2021-10-20 11:23:12 -0700
- Write a basic "call Rust from C" example (rust-lang/nomicon#296)
- Clarify the Safe vs. Unsafe Rust relationship (rust-lang/nomicon#294)
- Fix typo with respect to dangling pointer (rust-lang/nomicon#319)
## book
8 commits in eb1282ec444db94055fa9531b6f3f803e86bb382..fd9299792852c9a368cb236748781852f75cdac6
2021-09-16 21:17:09 -0400 to 2021-10-22 21:59:46 -0400
- Reword description to emphasize what return does in a match arm
- Correct backwards wording describing From impls. Fixesrust-lang/book#2829
- Remove multiple negatives, add examples. Fixesrust-lang/book#2833
- Fix capitalization in sidebar. Fixesrust-lang/book#2860
- fix quotes
- comments from nostarch and responses for chapter 2
- (rust-lang/book#2906)
- Merge pull request rust-lang/book#2892 from Enrico2/patch-1
## rust-by-example
1 commits in 9a60624fcad0140826c44389571dc622917cd632..27f1ff5e440ef78828b68ab882b98e1b10d9af32
2021-10-04 08:13:53 -0300 to 2021-10-13 08:04:40 -0300
- Added example of `impl Trait` as an argument (rust-lang/rust-by-example#1468)
## embedded-book
1 commits in 270fccd339e5972d9c900e788f197e81a0bcd956..51739471276b1776dea27cf562b974ef07e24685
2021-10-06 16:28:48 +0000 to 2021-10-17 16:48:42 +0000
- Fix typo in 'The Borrow Checker' (rust-embedded/book#305)
Avoid a branch on key being local for queries that use the same local and extern providers
Currently based on https://github.com/rust-lang/rust/pull/85810 as it slightly conflicts with it. Only the last two commits are new.
Prevent duplicate caller bounds candidates by exposing default substs in Unevaluated
Fixes https://github.com/rust-lang/rust/issues/89334
The changes introduced in https://github.com/rust-lang/rust/pull/87280 allowed for "duplicate" caller bounds candidates to be assembled that only differed in their default substs having been "exposed" or not and resulted in an ambiguity error during trait selection. To fix this we expose the defaults substs during the creation of the ParamEnv.
r? `@lcnr`
Fix and extent ControlFlow `traverse_inorder` example
Fix and extent ControlFlow `traverse_inorder` example
1. The existing example compiles on its own, but any usage fails to be monomorphised and so doesn't compile. Fix that by using Fn trait instead of FnMut.
2. Added an example usage of `traverse_inorder` showing how we can terminate the traversal early.
Fixes#90063
Add -Z no-unique-section-names to reduce ELF header bloat.
This change adds a new compiler flag that can help reduce the size of ELF binaries that contain many functions.
By default, when enabling function sections (which is the default for most targets), the LLVM backend will generate different section names for each function. For example, a function `func` would generate a section called `.text.func`. Normally this is fine because the linker will merge all those sections into a single one in the binary. However, starting with [LLVM 12](https://github.com/llvm/llvm-project/commit/ee5d1a04), the backend will also generate unique section names for exception handling, resulting in thousands of `.gcc_except_table.*` sections ending up in the final binary because some linkers like LLD don't currently merge or strip these EH sections (see discussion [here](https://reviews.llvm.org/D83655)). This can bloat the ELF headers and string table significantly in binaries that contain many functions.
The new option is analogous to Clang's `-fno-unique-section-names`, and instructs LLVM to generate the same `.text` and `.gcc_except_table` section for each function, resulting in a smaller final binary.
The motivation to add this new option was because we have a binary that ended up with so many ELF sections (over 65,000) that it broke some existing ELF tools, which couldn't handle so many sections.
Here's our old binary:
```
$ readelf --sections old.elf | head -1
There are 71746 section headers, starting at offset 0x2a246508:
$ readelf --sections old.elf | grep shstrtab
[71742] .shstrtab STRTAB 0000000000000000 2977204c ad44bb 00 0 0 1
```
That's an 11MB+ string table. Here's the new binary using this option:
```
$ readelf --sections new.elf | head -1
There are 43 section headers, starting at offset 0x29143ca8:
$ readelf --sections new.elf | grep shstrtab
[40] .shstrtab STRTAB 0000000000000000 29143acc 0001db 00 0 0 1
```
The whole binary size went down by over 20MB, which is quite significant.
Move back to linux builder on try builds
Apparently deleted the wrong line when trying to revert changes to try in #90100 which I now see still contains the do not merge commit -- maybe I forgot to force push the local changes I had pending or something.
r? `@pietroalbini`
Changed slice.swap documentation for better readability
The example exchanges the letters "b" and "d", these can be easily confused and are hard to read for people with dyslexia.
Therefore, I changed the example to a more easily readable one.
This is just a small fix and it's not urgent by any means, but I spent 5 minutes trying to understand why I couldn't see any change so I fixed it.
Anyway, thank you for all your works!
enable `i8mm` target feature on aarch64 and arm
As in https://github.com/rust-lang/stdarch/issues/1233, `i8mm` needs to be turned on to support the implementation of `vmmla` and `vusmmla`neon instructions in stdarch.
r? ``@Amanieu``
Rollup of 4 pull requests
Successful merges:
- #89889 (Use the "nice E0277 errors"[1] for `!Send` `impl Future` from foreign crate)
- #90127 (Do not mention a reexported item if it's private)
- #90143 (tidy: Remove submodules from edition exception list)
- #90238 (Add alias for guillaume.gomez@huawei.com)
Failed merges:
r? `@ghost`
`@rustbot` modify labels: rollup
Do not mention a reexported item if it's private
Fixes#90113
The _actual_ regression was introduced in #73652, then #88838 made it worse. This fixes the issue by not counting such an import as a candidate.
Use the "nice E0277 errors"[1] for `!Send` `impl Future` from foreign crate
Partly address #78543 by making the error quieter.
We don't have access to the `typeck` tables from foreign crates, so we
used to completely skip the new code when checking foreign crates. Now,
we carry on and don't provide as nice output (we don't clarify *what* is
making the `Future: !Send`), but at least we no longer emit a sea of
derived obligations in the output.
[1]: https://blog.rust-lang.org/inside-rust/2019/10/11/AsyncAwait-Not-Send-Error-Improvements.html
r? `@tmandry`
Cleanup LLVM multi-threading checks
The support for runtime multi-threading was removed from LLVM. Calls to
`LLVMStartMultithreaded` became no-ops equivalent to checking if LLVM
was compiled with support for threads http://reviews.llvm.org/D4216.
Build the query vtable directly.
Continuation of https://github.com/rust-lang/rust/pull/89978.
This shrinks the query interface and attempts to reduce the amount of function pointer calls.
Partly address #78543 by making the error quieter.
We don't have access to the `typeck` tables from foreign crates, so we
used to completely skip the new code when checking foreign crates. Now,
we carry on and don't provide as nice output (we don't clarify *what* is
making the `Future: !Send`), but at least we no longer emit a sea of
derived obligations in the output.
[1]: https://blog.rust-lang.org/inside-rust/2019/10/11/AsyncAwait-Not-Send-Error-Improvements.html
1. The existing example compiles on its own, but any usage fails
to be monomorphised and so doesn't compile. Fix that by using
a mutable reference as an input argument.
2. Added an example usage of `traverse_inorder` showing how we
can terminate the traversal early.
Fixes#90063
