Set max_atomic_width for riscv32*-esp-espidf to 32
Fixes#117305
> Since riscv32 does not have 64-bit atomic instructions, I do not believe there is any way to fix this problem other than setting max_atomic_width of these targets to 32.
This is a breaking change because Atomic\*64 will become unavailable, but all affected targets are tier 3, and the current Atomic*64 violates the standard library's API contract and can cause problems with code that rely on the standard library's atomic types being lock-free.
r? `@Amanieu`
cc `@ivmarkov` `@MabezDev`
Stabilize Ratified RISC-V Target Features
Stabilization PR for the ratified RISC-V target features. This stabilizes some of the target features tracked by #44839. This is also a part of #114544 and eventually needed for the RISC-V part of rust-lang/rfcs#3268.
There is a similar PR for the the stdarch crate which can be found at rust-lang/stdarch#1476.
This was briefly discussed on Zulip
(https://rust-lang.zulipchat.com/#narrow/stream/250483-t-compiler.2Frisc-v/topic/Stabilization.20of.20RISC-V.20Target.20Features/near/394793704).
Specifically, this PR stabilizes the:
* Atomic Instructions (A) on v2.0
* Compressed Instructions (C) on v2.0
* ~Double-Precision Floating-Point (D) on v2.2~
* ~Embedded Base (E) (Given as `RV32E` / `RV64E`) on v2.0~
* ~Single-Precision Floating-Point (F) on v2.2~
* Integer Multiplication and Division (M) on v2.0
* ~Vector Operations (V) on v1.0~
* Bit Manipulations (B) on v1.0 listed as `zba`, `zbc`, `zbs`
* Scalar Cryptography (Zk) v1.0.1 listed as `zk`, `zkn`, `zknd`, `zkne`, `zknh`, `zkr`, `zks`, `zksed`, `zksh`, `zkt`, `zbkb`, `zbkc` `zkbx`
* ~Double-Precision Floating-Point in Integer Register (Zdinx) on v1.0~
* ~Half-Precision Floating-Point (Zfh) on v1.0~
* ~Minimal Half-Precision Floating-Point (Zfhmin) on v1.0~
* ~Single-Precision Floating-Point in Integer Register (Zfinx) on v1.0~
* ~Half-Precision Floating-Point in Integer Register (Zhinx) on v1.0~
* ~Minimal Half-Precision Floating-Point in Integer Register (Zhinxmin) on v1.0~
r? `@Amanieu`
Consider alias bounds when computing liveness in NLL (but this time sound hopefully)
This is a revival of #116040, except removing the changes to opaque lifetime captures check to make sure that we're not triggering any unsoundness due to the lack of general existential regions and the currently-existing `ReErased` hack we use instead.
r? `@aliemjay` -- I appreciate you pointing out the unsoundenss in the previous iteration of this PR, and I'd like to hear that you're happy with this iteration of this PR before this goes back into FCP :>
Fixes#116794 as well
---
(mostly copied from #116040 and reworked slightly)
# Background
Right now, liveness analysis in NLL is a bit simplistic. It simply walks through all of the regions of a type and marks them as being live at points. This is problematic in the case of aliases, since it requires that we mark **all** of the regions in their args[^1] as live, leading to bugs like #42940.
In reality, we may be able to deduce that fewer regions are allowed to be present in the projected type (or "hidden type" for opaques) via item bounds or where clauses, and therefore ideally, we should be able to soundly require fewer regions to be live in the alias.
For example:
```rust
trait Captures<'a> {}
impl<T> Captures<'_> for T {}
fn capture<'o>(_: &'o mut ()) -> impl Sized + Captures<'o> + 'static {}
fn test_two_mut(mut x: ()) {
let _f1 = capture(&mut x);
let _f2 = capture(&mut x);
//~^ ERROR cannot borrow `x` as mutable more than once at a time
}
```
In the example above, we should be able to deduce from the `'static` bound on `capture`'s opaque that even though `'o` is a captured region, it *can never* show up in the opaque's hidden type, and can soundly be ignored for liveness purposes.
# The Fix
We apply a simple version of RFC 1214's `OutlivesProjectionEnv` and `OutlivesProjectionTraitDef` rules to NLL's `make_all_regions_live` computation.
Specifically, when we encounter an alias type, we:
1. Look for a unique outlives bound in the param-env or item bounds for that alias. If there is more than one unique region, bail, unless any of the outlives bound's regions is `'static`, and in that case, prefer `'static`. If we find such a unique region, we can mark that outlives region as live and skip walking through the args of the opaque.
2. Otherwise, walk through the alias's args recursively, as we do today.
## Limitation: Multiple choices
This approach has some limitations. Firstly, since liveness doesn't use the same type-test logic as outlives bounds do, we can't really try several options when we're faced with a choice.
If we encounter two unique outlives regions in the param-env or bounds, we simply fall back to walking the opaque via its args. I expect this to be mostly mitigated by the special treatment of `'static`, and can be fixed in a forwards-compatible by a more sophisticated analysis in the future.
## Limitation: Opaque hidden types
Secondly, we do not employ any of these rules when considering whether the regions captured by a hidden type are valid. That causes this code (cc #42940) to fail:
```rust
trait Captures<'a> {}
impl<T> Captures<'_> for T {}
fn a() -> impl Sized + 'static {
b(&vec![])
}
fn b<'o>(_: &'o Vec<i32>) -> impl Sized + Captures<'o> + 'static {}
```
We need to have existential regions to avoid [unsoundness](https://github.com/rust-lang/rust/pull/116040#issuecomment-1751628189) when an opaque captures a region which is not represented in its own substs but which outlives a region that does.
## Read more
Context: https://github.com/rust-lang/rust/pull/115822#issuecomment-1731153952 (for the liveness case)
More context: https://github.com/rust-lang/rust/issues/42940#issuecomment-455198309 (for the opaque capture case, which this does not fix)
[^1]: except for bivariant region args in opaques, which will become less relevant when we move onto edition 2024 capture semantics for opaques.
Bump stdarch submodule and remove special handling for LLVM intrinsics that are no longer needed
Bumps stdarch to pull https://github.com/rust-lang/stdarch/pull/1477, which reimplemented some functions with portable SIMD intrinsics instead of arch specific LLVM intrinsics.
Handling of those LLVM intrinsics is removed from cranelift codegen and miri.
cc `@RalfJung` `@bjorn3`
rustdoc: use JS to inline target type impl docs into alias
Preview docs:
- https://notriddle.com/rustdoc-html-demo-5/js-trait-alias/std/io/type.Result.html
- https://notriddle.com/rustdoc-html-demo-5/js-trait-alias-compiler/rustc_middle/ty/type.PolyTraitRef.html
This pull request also includes a bug fix for trait alias inlining across crates. This means more documentation is generated, and is why ripgrep runs slower (it's a thin wrapper on top of the `grep` crate, so 5% of its docs are now the Result type).
- Before, built with rustdoc 1.75.0-nightly (aa1a71e9e 2023-10-26), Result type alias method docs are missing: http://notriddle.com/rustdoc-html-demo-5/ripgrep-js-nightly/rg/type.Result.html
- After, built with this branch, all the methods on Result are shown: http://notriddle.com/rustdoc-html-demo-5/ripgrep-js-trait-alias/rg/type.Result.html
*Review note: This is mostly just reverting https://github.com/rust-lang/rust/pull/115201. The last commit has the new work in it.*
Fixes#115718
This is an attempt to balance three problems, each of which would
be violated by a simpler implementation:
- A type alias should show all the `impl` blocks for the target
type, and vice versa, if they're applicable. If nothing was
done, and rustdoc continues to match them up in HIR, this
would not work.
- Copying the target type's docs into its aliases' HTML pages
directly causes far too much redundant HTML text to be generated
when a crate has large numbers of methods and large numbers
of type aliases.
- Using JavaScript exclusively for type alias impl docs would
be a functional regression, and could make some docs very hard
to find for non-JS readers.
- Making sure that only applicable docs are show in the
resulting page requires a type checkers. Do not reimplement
the type checker in JavaScript.
So, to make it work, rustdoc stashes these type-alias-inlined docs
in a JSONP "database-lite". The file is generated in `write_shared.rs`,
included in a `<script>` tag added in `print_item.rs`, and `main.js`
takes care of patching the additional docs into the DOM.
The format of `trait.impl` and `type.impl` JS files are superficially
similar. Each line, except the JSONP wrapper itself, belongs to a crate,
and they are otherwise separate (rustdoc should be idempotent). The
"meat" of the file is HTML strings, so the frontend code is very simple.
Links are relative to the doc root, though, so the frontend needs to fix
that up, and inlined docs can reuse these files.
However, there are a few differences, caused by the sophisticated
features that type aliases have. Consider this crate graph:
```text
---------------------------------
| crate A: struct Foo<T> |
| type Bar = Foo<i32> |
| impl X for Foo<i8> |
| impl Y for Foo<i32> |
---------------------------------
|
----------------------------------
| crate B: type Baz = A::Foo<i8> |
| type Xyy = A::Foo<i8> |
| impl Z for Xyy |
----------------------------------
```
The type.impl/A/struct.Foo.js JS file has a structure kinda like this:
```js
JSONP({
"A": [["impl Y for Foo<i32>", "Y", "A::Bar"]],
"B": [["impl X for Foo<i8>", "X", "B::Baz", "B::Xyy"], ["impl Z for Xyy", "Z", "B::Baz"]],
});
```
When the type.impl file is loaded, only the current crate's docs are
actually used. The main reason to bundle them together is that there's
enough duplication in them for DEFLATE to remove the redundancy.
The contents of a crate are a list of impl blocks, themselves
represented as lists. The first item in the sublist is the HTML block,
the second item is the name of the trait (which goes in the sidebar),
and all others are the names of type aliases that successfully match.
This way:
- There's no need to generate these files for types that have no aliases
in the current crate. If a dependent crate makes a type alias, it'll
take care of generating its own docs.
- There's no need to reimplement parts of the type checker in
JavaScript. The Rust backend does the checking, and includes its
results in the file.
- Docs defined directly on the type alias are dropped directly in the
HTML by `render_assoc_items`, and are accessible without JavaScript.
The JSONP file will not list impl items that are known to be part
of the main HTML file already.
[JSONP]: https://en.wikipedia.org/wiki/JSONP
Allow target specs to use an LLD flavor, and self-contained linking components
This PR allows:
- target specs to use an LLD linker-flavor: this is needed to switch `x86_64-unknown-linux-gnu` to using LLD, and is currently not possible because the current flavor json serialization fails to roundtrip on the modern linker-flavors. This can e.g. be seen in https://github.com/rust-lang/rust/pull/115622#discussion_r1321312880 which explains where an `Lld::Yes` is ultimately deserialized into an `Lld::No`.
- target specs to declare self-contained linking components: this is needed to switch `x86_64-unknown-linux-gnu` to using `rust-lld`
- adds an end-to-end test of a custom target json simulating `x86_64-unknown-linux-gnu` being switched to using `rust-lld`
- disables codegen backends from participating because they don't support `-Zgcc-ld=lld` which is the basis of mcp510.
r? `@petrochenkov:` if the approach discussed https://github.com/rust-lang/rust/pull/115622#discussion_r1329403467 and on zulip would work for you: basically, see if we can emit only modern linker flavors in the json specs, but accept both old and new flavors while reading them, to fix the roundtrip issue.
The backwards compatible `LinkSelfContainedDefault` variants are still serialized and deserialized in `crt-objects-fallback`, while the spec equivalent of e.g. `-Clink-self-contained=+linker` is serialized into a different json object (with future-proofing to incorporate `crt-objects-fallback` in the future).
---
I've been test-driving this in https://github.com/rust-lang/rust/pull/113382 to test actually switching `x86_64-unknown-linux-gnu` to `rust-lld` (and fix what needs to be fixed in CI, bootstrap, etc), and it seems to work fine.
Centralize command running in boostrap (part one)
This PR tries to consolidate the various `run, try_run, run_quiet, run_quiet_delaying_failure, run_delaying_failure` etc. methods on `Builder`. This PR only touches command execution which doesn't produce output that would be later read by bootstrap, and it also only refactors spawning of commands that happens after a builder is created (commands executed during download & git submodule checkout are left as-is, for now).
The `run_cmd` method is quite meaty, but I expect that it will be changing rapidly soon, so I considered it easy to kept everything in a single method, and only after things settle down a bit, then maybe again split it up a bit.
I still kept the original shortcut methods like `run_quiet_delaying_failure`, but they now only delegate to `run_cmd`. I tried to keep the original behavior (or as close to it as possible) for all the various commands, but it is a giant mess, so there may be some deviations. Notably, `cmd.output()` is now always called, instead of just `status()`, which was called previously in some situations.
Apart from the refactored methods, there is also `Config::try_run`, `check_run`, methods that run commands that produce output, oh my… that's left for follow-up PRs :)
The driving goal of this (and following) refactors is to centralize command execution in bootstrap on a single place, to make command mocking feasible.
r? `@onur-ozkan`
Never consider raw pointer casts to be trival
HIR typeck tries to figure out which casts are trivial by doing them as
coercions and seeing whether this works. Since HIR typeck is oblivious
of lifetimes, this doesn't work for pointer casts that only change the
lifetime of the pointee, which are, as borrowck will tell you, not
trivial.
This change makes it so that raw pointer casts are never considered
trivial.
This also incidentally fixes the "trivial cast" lint false positive on
the same code. Unfortunately, "trivial cast" lints are now never emitted
on raw pointer casts, even if they truly are trivial. This could be
fixed by also doing the lint in borrowck for raw pointers specifically.
fixes#113257
Prepare the `bootstrap` tool for the new check-cfg syntax
This PR prepare the `bootstrap` tool for the [new check-cfg syntax](https://github.com/rust-lang/rust/pull/111072) as well as the according [changes to Cargo](https://github.com/rust-lang/cargo/pull/12845).
~~Note that while the new syntax can technically available on stage > 2, we actually cannot use it since we need a cargo version that supports the new syntax which won't happen until the next beta bump (if I understand everything correctly).~~
r? bootstrap
Mark .rmeta files as /SAFESEH on x86 Windows.
Chrome links .rlibs with /WHOLEARCHIVE or -Wl,--whole-archive to prevent the linker from discarding static initializers. This works well, except on Windows x86, where lld complains:
error: /safeseh: lib.rmeta is not compatible with SEH
The fix is simply to mark the .rmeta as SAFESEH aware. This is trivially true, since the metadata file does not contain any executable code.
Stop telling people to submit bugs for internal feature ICEs
This keeps track of usage of internal features, and changes the message to instead tell them that using internal features is not supported.
I thought about several ways to do this but now used the explicit threading of an `Arc<AtomicBool>` through `Session`. This is not exactly incremental-safe, but this is fine, as this is set during macro expansion, which is pre-incremental, and also only affects the output of ICEs, at which point incremental correctness doesn't matter much anyways.
See [MCP 620.](https://github.com/rust-lang/compiler-team/issues/596)
Modernize rustc_builtin_macros generics helpers
- Rustfmt-compatible formatting for the code snippets in comments
- Eliminate an _"Extra scope required"_ obsoleted by NLL
Uplift `ClauseKind` and `PredicateKind` into `rustc_type_ir`
Uplift `ClauseKind` and `PredicateKind` into `rustc_type_ir`.
Blocked on #116951
r? `@ghost`
Validate `feature` and `since` values inside `#[stable(…)]`
Previously the string passed to `#[unstable(feature = "...")]` would be validated as an identifier, but not `#[stable(feature = "...")]`. In the standard library there were `stable` attributes containing the empty string, and kebab-case string, neither of which should be allowed.
Pre-existing validation of `unstable`:
```rust
// src/lib.rs
#![allow(internal_features)]
#![feature(staged_api)]
#![unstable(feature = "kebab-case", issue = "none")]
#[unstable(feature = "kebab-case", issue = "none")]
pub struct Struct;
```
```console
error[E0546]: 'feature' is not an identifier
--> src/lib.rs:5:1
|
5 | #![unstable(feature = "kebab-case", issue = "none")]
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
```
For an `unstable` attribute, the need for an identifier is obvious because the downstream code needs to write a `#![feature(...)]` attribute containing that identifier. `#![feature(kebab-case)]` is not valid syntax and `#![feature(kebab_case)]` would not work if that is not the name of the feature.
Having a valid identifier even in `stable` is less essential but still useful because it allows for informative diagnostic about the stabilization of a feature. Compare:
```rust
// src/lib.rs
#![allow(internal_features)]
#![feature(staged_api)]
#![stable(feature = "kebab-case", since = "1.0.0")]
#[stable(feature = "kebab-case", since = "1.0.0")]
pub struct Struct;
```
```rust
// src/main.rs
#![feature(kebab_case)]
use repro::Struct;
fn main() {}
```
```console
error[E0635]: unknown feature `kebab_case`
--> src/main.rs:3:12
|
3 | #![feature(kebab_case)]
| ^^^^^^^^^^
```
vs the situation if we correctly use `feature = "snake_case"` and `#![feature(snake_case)]`, as enforced by this PR:
```console
warning: the feature `snake_case` has been stable since 1.0.0 and no longer requires an attribute to enable
--> src/main.rs:3:12
|
3 | #![feature(snake_case)]
| ^^^^^^^^^^
|
= note: `#[warn(stable_features)]` on by default
```
Windows: Support sub-millisecond sleep
Use `CreateWaitableTimerExW` with `CREATE_WAITABLE_TIMER_HIGH_RESOLUTION`. Does not work before Windows 10, version 1803 so in that case we fallback to using `Sleep`.
I've created a `WaitableTimer` type so it can one day be adapted to also support waiting to an absolute time (which has been talked about). Note though that it currently returns `Err(())` because we can't do anything with the errors other than fallback to the old `Sleep`. Feel free to tell me to do errors properly. It just didn't seem worth constructing an `io::Error` if we're never going to surface it to the user. And it *should* all be infallible anyway unless the OS is too old to support it.
Closes#43376
Handle `ReErased` in responses in new solver
There are legitimate cases in the compiler where we return `ReErased` for lifetimes that are uncaptured in the hidden type of an opaque. For example, in the test committed below, we ignore ignore the bivariant lifetimes of an opaque when it's inferred as the hidden type of another opaque. This may result in a `type_of(Opaque)` call returning a type that references `ReErased`. Let's handle this gracefully in the new solver.
Also added a `rustc_hidden_type_of_opaques` attr to print hidden types. This seems useful for opaques.
r? lcnr
time: use clock_gettime on macos
Replace `gettimeofday` with `clock_gettime(CLOCK_REALTIME)` on:
```
all(target_os = "macos", not(target_arch = "aarch64")),
target_os = "ios",
target_os = "watchos",
target_os = "tvos"
))]
```
`gettimeofday` was first used in
cc367edd95
which predated the introduction of `clock_gettime` support in macOS
10.12 Sierra which became the minimum supported version in
58bbca958d917a89124da248735926f86c59a149.
Replace `mach_{absolute_time,timebase_info}` with
`clock_gettime(CLOCK_REALTIME)` on:
```
all(target_os = "macos", not(target_arch = "aarch64")),
target_os = "ios",
target_os = "watchos",
target_os = "tvos"
))]
```
`mach_{absolute_time,timebase_info}` were first used in
cc367edd95
which predated the introduction of `clock_gettime` support in macOS
10.12 Sierra which became the minimum supported version in
58bbca958d917a89124da248735926f86c59a149.
Note that this change was made for aarch64 in
5008a317ce8e508c390ed12bff281f307313376e which predated 10.12 becoming
the minimum supported version. The discussion took place in
https://github.com/rust-lang/rust/issues/91417 and in particular
https://github.com/rust-lang/rust/issues/91417#issuecomment-992151582
and
https://github.com/rust-lang/rust/issues/91417#issuecomment-1033048064
are relevant.
Improve android-ndk property interface
Re-creating #102994 which was closed.
---
PR #105716 added support for NDK r25b, and removed support for r15. Since the switch to r25b would have broken existing r15 users anyway, let's take the opportunity to make the interface more user friendly.
Firstly move the android-ndk property to [build] instead of the targets. This is possible now that the NDK has obsoleted the concept of target-specific toolchains.
Also make the property take the NDK root directory instead of the "toolchains/llvm/prebuilt/<host tag>" subdirectory.
Separate move path tracking between borrowck and drop elaboration.
The primary goal of this PR is to skip creating a `MovePathIndex` for path that do not need dropping in drop elaboration.
The 2 first commits are cleanups.
The next 2 commits displace `move` errors from move-path builder to borrowck. Move-path builder keeps the same logic, but does not carry error information any more.
The remaining commits allow to filter `MovePathIndex` creation according to types. This is used in drop elaboration, to avoid computing dataflow for paths that do not need dropping.
Rollup of 6 pull requests
Successful merges:
- #107159 (rand use getrandom for freebsd (available since 12.x))
- #116859 (Make `ty::print::Printer` take `&mut self` instead of `self`)
- #117046 (return unfixed len if pat has reported error)
- #117070 (rustdoc: wrap Type with Box instead of Generics)
- #117074 (Remove smir from triage and add me to stablemir)
- #117086 (Update .mailmap to promote my livename)
r? `@ghost`
`@rustbot` modify labels: rollup
report `unused_import` for empty reexports even it is pub
Fixes#116032
An easy fix. r? `@petrochenkov`
(Discovered this issue while reviewing #115993.)
Add `-Zstack-protector` test for Windows targets
Add variants of the `stack-protector-heuristics-effect.rs` test for 32-bit and 64-bit MSVC Windows and update the original test to run on GNU Windows targets.
I added two tests instead of trying to modify the original because:
- MSVC uses a different function name (`__security_check_cookie` to perform the test rather than doing the test inline and calling `__stack_chk_fail`).
- LLVM's stack protection pass doesn't currently support generating checks for [frames with funclet based EH personality](37fd3c96b9/llvm/lib/CodeGen/StackProtector.cpp (L103C1-L109C4)).
- 32-bit Windows uses classic EH while 64-bit Windows uses table-based EH which results in slightly different codegen.
[CI run with test passing on {i686,x86_64}-{msvc,mingw}](https://github.com/rust-lang/rust/actions/runs/6275450644/job/17042958375?pr=116037)
Implement FusedIterator for DecodeUtf16 when the inner iterator does
I have just implemented an iterator that wraps `DecodeUtf16` and wanted to implement `FusedIterator` for my iterator when I noticed that `DecodeUtf16` currently doesn't implement `FusedIterator` at all.
A quick look at the code of `DecodeUtf16` revealed that `DecodeUtf16::next` only returns `None` when its inner iterator returns `None`:
3462f79e94/library/core/src/char/decode.rs (L45)
As a result, we can implement `FusedIterator` for `DecodeUtf16` when the inner iterator does.
I'm following the example of #96397 here and consider this change minor and non-controversial, which is why I haven't added an RFC. I have also added the required feature name (`"decode_utf16_fused_iterator"`), however without adding a chapter to the Rust Unstable book (same as #96397).
Fix exit status / wait status on non-Unix cfg(unix) platforms
Fixes#114593
Needs FCP due to behavioural changes (NB only on non-Unix `#[cfg(unix)]` platforms).
Also, I think this is likely to break in CI. I have not been yet able to compile the new bits of `process_unsupported.rs`, although I have compiled the new module. I'd like some help from people familiar with eg emscripten and fuchsia (which are going to be affected, I think).
Implement `slice::split_once` and `slice::rsplit_once`
Feature gate is `slice_split_once` and tracking issue is #112811. These are equivalents to the existing `str::split_once` and `str::rsplit_once` methods.
Fix generic bound of `str::SplitInclusive`'s `DoubleEndedIterator` impl
`str::SplitInclusive`'s `DoubleEndedIterator` implementation currently uses a `ReverseSearcher` bound for the corresponding searcher. A `DoubleEndedSearcher` bound should have been used instead.
`DoubleEndedIterator` requires that repeated `next_back` calls produce the same items as repeated `next` calls, in opposite order. `ReverseSearcher` lets you search starting from the back of a string, but it makes no guarantees about how its matches correspond to the matches found by a forward search. `DoubleEndedSearcher` is a subtrait of `ReverseSearcher` and does require that the same matches are found in both directions.
This bug fix is a breaking change. Calling `next_back` on `"a+++b".split_inclusive("++")` is currently accepted with repeated calls producing `"b"` and `"a+++"`, while forward iteration yields `"a++"` and `"+b"`. Also see https://github.com/rust-lang/rust/issues/100756#issuecomment-1221307166 for more details.
I believe that this is the only iterator that uses this bound incorrectly — other related iterators such as `str::Split` do have a `DoubleEndedSearcher` bound for their `DoubleEndedIterator` implementation. And `slice::SplitInclusive` doesn't face this problem at all because it doesn't use patterns, only a predicate.
cc `@SkiFire13`
`waitqueue` clarifications for SGX platform
The documentation of `waitqueue` functions on the `x86_64-fortanix-unknown-sgx` platform is incorrect at some places and on others missing. This PR improves upon this.
cc: `@jethrogb`
core library: Disable fpmath tests for i586 ...
This patch disables the floating-point epsilon test for i586 since x87 registers are too imprecise and can't produce the expected results.
Improve UdpSocket documentation
I tried working with `UdpSocket` and ran into `EINVAL` errors with no clear indication of what causes the error. Also, it was uncharacteristically hard to figure this module out, compared to other Rust `std` modules.
1. `send` and `send_to` return a `usize` This one is just clarity. Usually, returned `usize`s indicate that the buffer might have only been sent partially. This is not the case with UDP. Since that `usize` must always be `buffer.len()`, I have documented that.
2. `bind` limits `connect` and `send_to` When you bind to a limited address space like localhost, you can only `connect` to addresses in that same address space. Error kind: `AddrNotAvailable`.
3. `connect`ing to localhost locks you to localhost On Linux, if you first `connect` to localhost, subsequent `connect`s to
non-localhost addresses fail. Error kind: `InvalidInput`.
For debugging the third one, it was really hard to find someone else who already had that problem. I only managed to find this thread: https://www.mail-archive.com/netdev@vger.kernel.org/msg159519.html
bootstrap major change detection implementation
The use of `changelog-seen` and `bootstrap/CHANGELOG.md` has not been functional in any way for many years. We often do major/breaking changes but never update the changelog file or the `changelog-seen`. This is an alternative method for tracking major or breaking changes and informing developers when such changes occur.
Example output when bootstrap detects a major change:
