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Author SHA1 Message Date
Manish Goregaokar
ae79c30d74
Rollup merge of #72445 - anp:stabilize-track-caller, r=oli-obk
Stabilize `#[track_caller]`.

# Stabilization Report

RFC: [2091]
Tracking issue: https://github.com/rust-lang/rust/issues/47809

## Summary

From the [rustc-dev-guide chapter][dev-guide]:

> Take this example program:

```rust
fn main() {
    let foo: Option<()> = None;
    foo.unwrap(); // this should produce a useful panic message!
}
```

> Prior to Rust 1.42, panics like this `unwrap()` printed a location in libcore:

```
$ rustc +1.41.0 example.rs; example.exe
thread 'main' panicked at 'called `Option::unwrap()` on a `None` value',...core\macros\mod.rs:15:40
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace.
```

> As of 1.42, we get a much more helpful message:

```
$ rustc +1.42.0 example.rs; example.exe
thread 'main' panicked at 'called `Option::unwrap()` on a `None` value', example.rs:3:5
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
```

> These error messages are achieved through a combination of changes to `panic!` internals to make use of `core::panic::Location::caller` and a number of `#[track_caller]` annotations in the standard library which propagate caller information.

The attribute adds an implicit caller location argument to the ABI of annotated functions, but does not affect the type or MIR of the function. We implement the feature entirely in codegen and in the const evaluator.

## Bottom Line

This PR stabilizes the use of `#[track_caller]` everywhere, including traits and extern blocks. It also stabilizes `core::panic::Location::caller`, although the use of that function in a const context remains gated by `#![feature(const_caller_location)]`.

The implementation for the feature already changed the output of panic messages for a number of std functions, as described in the [1.42 release announcement]. The attribute's use in `Index` and `IndexMut` traits is visible to users since 1.44.

## Tests

All of the tests for this feature live under [src/test/ui/rfc-2091-track-caller][tests] in the repo.

Noteworthy cases:

* [use of attr in std]
  * validates user-facing benefit of the feature
* [trait attribute inheritance]
  * covers subtle behavior designed during implementation and not RFC'd
* [const/codegen equivalence]
  * this was the result of a suspected edge case and investigation
* [diverging function support]
  * covers an unresolved question from the RFC
* [fn pointers and shims]
  * covers important potential sources of unsoundness

## Documentation

The rustc-dev-guide now has a chapter on [Implicit Caller Location][dev-guide].

I have an [open PR to the reference][attr-reference-pr] documenting the attribute.

The intrinsic's [wrapper] includes some examples as well.

## Implementation History

* 2019-10-02: [`#[track_caller]` feature gate (RFC 2091 1/N) #65037](https://github.com/rust-lang/rust/pull/65037)
  * Picked up the patch that @ayosec had started on the feature gate.
* 2019-10-13: [Add `Instance::resolve_for_fn_ptr` (RFC 2091 #2/N) #65182](https://github.com/rust-lang/rust/pull/65182)
* 2019-10-20: ~~[WIP Add MIR argument for #[track_caller] (RFC 2091 3/N) #65258](https://github.com/rust-lang/rust/pull/65258)~~
  * Abandoned approach to send location as a MIR argument.
* 2019-10-28: [`std::panic::Location` is a lang_item, add `core::intrinsics::caller_location` (RFC 2091 3/N) #65664](https://github.com/rust-lang/rust/pull/65664)
* 2019-12-07: [Implement #[track_caller] attribute. (RFC 2091 4/N) #65881](https://github.com/rust-lang/rust/pull/65881)
* 2020-01-04: [libstd uses `core::panic::Location` where possible. #67137](https://github.com/rust-lang/rust/pull/67137)
* 2020-01-08: [`Option::{expect,unwrap}` and `Result::{expect, expect_err, unwrap, unwrap_err}` have `#[track_caller]` #67887](https://github.com/rust-lang/rust/pull/67887)
* 2020-01-20: [Fix #[track_caller] and function pointers #68302](https://github.com/rust-lang/rust/pull/68302) (fixed #68178)
* 2020-03-23: [#[track_caller] in traits #69251](https://github.com/rust-lang/rust/pull/69251)
* 2020-03-24: [#[track_caller] on core::ops::{Index, IndexMut}. #70234](https://github.com/rust-lang/rust/pull/70234)
* 2020-04-08 [Support `#[track_caller]` on functions in `extern "Rust" { ... }` #70916](https://github.com/rust-lang/rust/pull/70916)

## Unresolveds

### From the RFC

> Currently the RFC simply prohibit applying #[track_caller] to trait methods as a future-proofing
> measure.

**Resolved.** See the dev-guide documentation and the tests section above.

> Diverging functions should be supported.

**Resolved.** See the tests section above.

> The closure foo::{{closure}} should inherit most attributes applied to the function foo, ...

**Resolved.** This unknown was related to specifics of the implementation which were made irrelevant by the final implementation.

### Binary Size

I [instrumented track_caller to use custom sections][measure-size] in a local build and discovered relatively minor binary size usage for the feature overall. I'm leaving the issue open to discuss whether we want to upstream custom section support.

There's an [open issue to discuss mitigation strategies][mitigate-size]. Some decisions remain about the "right" strategies to reduce size without overly constraining the compiler implementation. I'd be excited to see someone carry that work forward but my opinion is that we shouldn't block stabilization on implementing compiler flags for redaction.

### Specialization

There's an [open issue][specialization] on the semantics of the attribute in specialization chains. I'm inclined to move forward with stabilization without an exact resolution here given that specialization is itself unstable, but I also think it should be an easy question to resolve.

### Location only points to the start of a call span

https://github.com/rust-lang/rust/issues/69977 was resolved by https://github.com/rust-lang/rust/pull/73182, and the next step should probably be to [extend `Location` with a notion of the end of a call](https://github.com/rust-lang/rust/issues/73554).

### Regression of std's panic messages

#70963 should be resolved by serializing span hygeine to crate metadata: https://github.com/rust-lang/rust/issues/68686.

[2091]: https://github.com/rust-lang/rfcs/blob/master/text/2091-inline-semantic.md
[dev-guide]: https://rustc-dev-guide.rust-lang.org/codegen/implicit-caller-location.html
[specialization]: https://github.com/rust-lang/rust/issues/70293
[measure-size]: https://github.com/rust-lang/rust/issues/70579
[mitigate-size]: https://github.com/rust-lang/rust/issues/70580
[attr-reference-pr]: https://github.com/rust-lang/reference/pull/742
[wrapper]: https://doc.rust-lang.org/nightly/core/panic/struct.Location.html#method.caller
[tests]: https://github.com/rust-lang/rust/tree/master/src/test/ui/rfc-2091-track-caller
[const/codegen equivalence]: https://github.com/rust-lang/rust/blob/master/src/test/ui/rfc-2091-track-caller/caller-location-fnptr-rt-ctfe-equiv.rs
[diverging function support]: https://github.com/rust-lang/rust/blob/master/src/test/ui/rfc-2091-track-caller/diverging-caller-location.rs
[use of attr in std]: https://github.com/rust-lang/rust/blob/master/src/test/ui/rfc-2091-track-caller/std-panic-locations.rs
[fn pointers and shims]: https://github.com/rust-lang/rust/blob/master/src/test/ui/rfc-2091-track-caller/tracked-fn-ptr-with-arg.rs
[trait attribute inheritance]: https://github.com/rust-lang/rust/blob/master/src/test/ui/rfc-2091-track-caller/tracked-trait-impls.rs
[1.42 release announcement]: https://blog.rust-lang.org/2020/03/12/Rust-1.42.html#useful-line-numbers-in-option-and-result-panic-messages
2020-07-01 07:42:33 -07:00
Manish Goregaokar
33f8ce287a
Rollup merge of #72369 - Lucretiel:socketaddr-parse, r=dtolnay
Bring net/parser.rs up to modern up to date with modern rust patterns

The current implementation of IP address parsing is very unidiomatic; it's full of `if` / `return` / `is_some` / `is_none` instead of `?`, `loop` with manual index tracking; etc. Went through and did and cleanup to try to bring it in line with modern sensibilities.

The obvious concern with making changes like this is "make sure you understand why it's written that way before changing it". Looking through the commit history for this file, there are several much smaller commits that make similar changes (For instance, 3024c1434a, 4f3ab4986e, 79f876495b), and there don't seem to be any commits in the history that indicate that this lack of idiomaticity is related to specific performance needs (ie, there aren't any commits that replace a `for` loop with a `loop` and a manual index count). In fact, the basic shape of the file is essentially unchanged from its initial commit back in 2015.

Made the following changes throughout the IP address parser:
- Replaced all uses of `is_some()` / `is_none()` with `?`.
- "Upgraded" loops wherever possible; ie, replace `while` with `for`, etc.
    - Removed all cases of manual index tracking / incrementing.
- Renamed several single-character variables with more expressive names.
- Replaced several manual control flow segments with equivalent adapters (such as `Option::filter`).
- Removed `read_seq_3`; replaced with simple sequences of `?`.
- Parser now reslices its state when consuming, rather than carrying a separate state and index variable.
- `read_digit` now uses `char::to_digit`.
- Added comments throughout, especially in the complex IPv6 parsing logic.
- Added comprehensive local unit tests for the parser to validate these changes.
2020-07-01 07:42:32 -07:00
Adam Perry
f07d10db7c Stabilize #[track_caller].
Does not yet make its constness stable, though. Use of
`Location::caller` in const contexts is still gated by
`#![feature(const_caller_location)]`.
2020-06-30 22:22:32 -07:00
Nathan West
3ab7ae39ec
Bring net/parser.rs up to modern up to date with modern rust patterns
Made the following changes throughout the IP address parser:
- Replaced all uses of `is_some()` / `is_none()` with `?`.
- "Upgraded" loops wherever possible; ie, replace `while` with `for`, etc.
    - Removed all cases of manual index tracking / incrementing.
- Renamed several single-character variables with more expressive names.
- Replaced several manual control flow segments with equivalent adapters (such as `Option::filter`).
- Removed `read_seq_3`; replaced with simple sequences of `?`.
- Parser now reslices its state when consuming, rather than carrying a separate state and index variable.
- `read_digit` now uses `char::to_digit`.
- Removed unnecessary casts back and forth between u8 and u32
- Added comments throughout, especially in the complex IPv6 parsing logic.
- Added comprehensive local unit tests for the parser to validate these changes.
2020-06-30 11:44:14 -07:00
Manish Goregaokar
5304511fbc
Rollup merge of #73826 - cjrh:cjrh-patch-1, r=jonas-schievink
Fix docstring typo
2020-06-28 08:30:34 -07:00
Manish Goregaokar
8b92eecbc2
Rollup merge of #73817 - jumbatm:rename-to-clashing-extern-declarations, r=petrochenkov
Rename clashing_extern_decl to clashing_extern_declarations.

Rename clashing_extern_decl to clashing_extern_declarations to bring in-line with lint naming conventions.

Fixes #73802.

r? @petrochenkov
2020-06-28 08:30:33 -07:00
bors
25687caa2e Auto merge of #73830 - Manishearth:rollup-8k68ysm, r=Manishearth
Rollup of 10 pull requests

Successful merges:

 - #72796 (MIR sanity check: validate types on assignment)
 - #73243 (Add documentation to point to `File::open` or `OpenOptions::open` instead of `is_file` to check read/write possibility)
 - #73525 (Prepare for LLVM 11)
 - #73672 (Adds a clearer message for when the async keyword is missing from a f…)
 - #73708 (Explain move errors that occur due to method calls involving `self` (take two))
 - #73758 (improper_ctypes: fix remaining `Reveal:All`)
 - #73763 (errors: use `-Z terminal-width` in JSON emitter)
 - #73796 (replace more `DefId`s with `LocalDefId`)
 - #73797 (fix typo in self-profile.md)
 - #73809 (Add links to fs::DirEntry::metadata)

Failed merges:

r? @ghost
2020-06-28 08:26:22 +00:00
Manish Goregaokar
cdb59d9041
Rollup merge of #73809 - robyoung:docs/add-links-to-DirEntry-metadata, r=hanna-kruppe
Add links to fs::DirEntry::metadata

`fs::DirEntry::metadata` doesn't traverse symlinks. It is not immediately clear what to do if you do want to traverse symlinks. This change adds links to the two other `metadata` functions that will follow symlinks.
2020-06-27 22:30:06 -07:00
Manish Goregaokar
6a944c15ab
Rollup merge of #73243 - poliorcetics:discourage-is-file, r=Amanieu
Add documentation to point to `File::open` or `OpenOptions::open` instead of `is_file` to check read/write possibility

Fixes #64170.

This adds documentation to point user towards `!is_dir` instead of `is_file` when all they want to is read from a source.

I ran `rg "fn is_file\("` to find all `is_file` methods, I hope I did not miss one.
2020-06-27 22:29:52 -07:00
bors
3b4a3d68b5 Auto merge of #72705 - Lucretiel:stdio-forwarding, r=Amanieu
Added io forwarding methods to the stdio structs

Added methods to forward the `io::Read` and `io::Write` methods of the myriad wrapper structs in `stdio.rs` to their underlying readers / writers. This is especially important for the structs on the outside of a locking boundary, to ensure that the lock isn't being dropped and re-acquired in a loop.
2020-06-28 04:16:52 +00:00
Caleb Hattingh
8291a22dd4
Fix docstring typo 2020-06-28 13:26:09 +10:00
jumbatm
c72a5dd9d3 Rename the lint to clashing_extern_declarations.
Also, run RustFmt on the clashing_extern_fn test case and update
stderrs.
2020-06-28 10:11:29 +10:00
Alexis Bourget
8e8c54aa3a Added the parapgrah to path::Path::is_file too 2020-06-27 22:59:47 +02:00
Rob Young
0e0584f290 Add links to fs::DirEntry::metadata
`fs::DirEntry::metadata` doesn't traverse symlinks. It is not immediately
clear what to do if you do want to traverse symlinks. This change adds
links to the two other `metadata` functions that will follow symlinks.
2020-06-27 19:32:19 +01:00
Alexis Bourget
d25d6c5bd8 Update the documentation to point to open instead of is_file and is_dir 2020-06-27 18:10:58 +02:00
Manish Goregaokar
bc10bb02f5
Rollup merge of #73718 - poliorcetics:super-keyword, r=shepmaster
Document the super keyword

Partial fix of #34601.

Quite short, just a small example and a link to the reference.

@rustbot modify labels: T-doc,C-enhancement
2020-06-26 13:57:41 -07:00
Manish Goregaokar
8d9c00d7f1
Rollup merge of #73694 - poliorcetics:self-upper-keyword, r=Mark-Simulacrum
Document the Self keyword

Partial fix of #34601.

Document the `Self` keyword.

This contains simple examples of the places where `Self` can be used.
2020-06-26 13:57:39 -07:00
Manish Goregaokar
38cbf158b8
Rollup merge of #72937 - AdrianCX:master, r=nikomatsakis
Fortanix SGX target libunwind build process changes

Ticket: https://github.com/fortanix/rust-sgx/issues/174
LLVM related changes (merged): https://github.com/rust-lang/llvm-project/pull/57

Description: libunwind changes needed to run code in sgx environment via rust-sgx.

Target that uses this in rust: x86_64-fortanix-unknown-sgx.

Without this change, rust std for this toolchain is forced to use a precompiled library loaded via environment variable.

With this change we act the same as musl target.
2020-06-26 13:57:26 -07:00
Manish Goregaokar
131e25401c
Rollup merge of #73648 - poliorcetics:return-keyword, r=joshtriplett
Document the return keyword

Partial fix of #34601.

This documents the `return` keyword with two short example to explain it is not needed for the last expression in a function and a long example to show its use when interrupting a function execution early.

I did not put a link to the reference since the only link I found was https://doc.rust-lang.org/stable/reference/expressions/return-expr.html#return-expressions.

@rustbot modify labels: T-doc,C-enhancement
2020-06-25 18:00:20 -07:00
Manish Goregaokar
f91330abfa
Rollup merge of #73621 - poliorcetics:mut-keyword, r=steveklabnik
Document the mut keyword

Partial fix for #34601.

Documentation for the `mut` keyword. I think it's okay for it to be quite short, this is not the book not the reference, but if you find something is missing, do not hesitate to tell me.
2020-06-25 18:00:18 -07:00
Manish Goregaokar
01a293a838
Rollup merge of #73619 - poliorcetics:mod-keyword, r=steveklabnik
Document the mod keyword

Partial fix for #34601 .

Documentation for the `mod` keyword.
2020-06-25 18:00:16 -07:00
Manish Goregaokar
5158b3c998
Rollup merge of #72617 - eduardosm:panicking, r=Amanieu
Add a fast path for `std:🧵:panicking`.

This is done by adding a global atomic variable (non-TLS) that counts how many threads are panicking. In order to check if the current thread is panicking, this variable is read and, if it is zero, no thread (including the one where `panicking` is being called) is panicking and `panicking` can return `false` immediately without needing to access TLS. If the global counter is not zero, the local counter is accessed from TLS to check if the current thread is panicking.
2020-06-25 18:00:02 -07:00
Alexis Bourget
5232e2025f Document the super keyword 2020-06-25 11:40:07 +02:00
Alexis Bourget
3d09017477 Add a compile fail example, binding -> variable, apply suggestions 2020-06-25 10:05:30 +02:00
Dylan DPC
a5839f35b6
Rollup merge of #73688 - poliorcetics:self-keyword, r=joshtriplett
Document the self keyword

Partial fix of #34601.

This documents the `self` keyword, adding several examples and a link to the reference.
2020-06-25 02:03:40 +02:00
Dylan DPC
67db7a2d05
Rollup merge of #72700 - davidtwco:issue-66220-improper-ctypes-declarations, r=lcnr,varkor
`improper_ctypes_definitions` lint

Addresses #19834, #66220, and #66373.

This PR takes another attempt at #65134 (reverted in #66378). Instead of modifying the existing `improper_ctypes` lint to consider `extern "C" fn` definitions in addition to `extern "C" {}` declarations, this PR adds a new lint - `improper_ctypes_definitions` - which only applies to `extern "C" fn` definitions.

In addition, the `improper_ctype_definitions` lint differs from `improper_ctypes` by considering `*T` and `&T` (where `T: Sized`) FFI-safe (addressing #66220).

There wasn't a clear consensus in #66220 (where the issues with #65134 were primarily discussed) on the approach to take, but there has [been some discussion in Zulip](https://rust-lang.zulipchat.com/#narrow/stream/131828-t-compiler/topic/.2366220.20improper_ctypes.20definitions.20vs.20declarations/near/198903086). I fully expect that we'll want to iterate on this before landing.

cc @varkor + @shepmaster (from #19834) @hanna-kruppe (active in discussing #66220), @SimonSapin (#65134 caused problems for Servo, want to make sure that this PR doesn't)
2020-06-25 02:03:32 +02:00
Eduardo Sánchez Muñoz
771a1d8e0a Make std::panicking::panic_count::is_zero inline and move the slow path into a separate cold function. 2020-06-24 18:17:27 +02:00
Alexis Bourget
f44b8b96aa Document the Self keyword 2020-06-24 15:00:05 +02:00
Dylan DPC
38c85b7393
Rollup merge of #73638 - yuqio:remove-unused-crate-imports, r=nikomatsakis
Remove unused crate imports in 2018 edition crates

Closes #73570
2020-06-24 14:28:33 +02:00
Alexis Bourget
03661630c9 Document the self keyword 2020-06-24 13:52:57 +02:00
David Wood
14ea7a777f
lints: add improper_ctypes_definitions
This commit adds a new lint - `improper_ctypes_definitions` - which
functions identically to `improper_ctypes`, but on `extern "C" fn`
definitions (as opposed to `improper_ctypes`'s `extern "C" {}`
declarations).

Signed-off-by: David Wood <david@davidtw.co>
2020-06-24 12:09:35 +01:00
Adrian Cruceru
f3b1582bb9 Update libunwind build process for x86_64-fortanix-unknown-sgx target 2020-06-24 11:28:41 +02:00
Alexis Bourget
d8ea10c95f Document the return keyword
Apply suggestions from code review

Co-authored-by: Josh Triplett <josh@joshtriplett.org>
2020-06-24 09:23:55 +02:00
bors
3b1c08c68c Auto merge of #73635 - Dylan-DPC:rollup-b4wbp42, r=Dylan-DPC
Rollup of 7 pull requests

Successful merges:

 - #71756 (add Windows system error codes that should map to io::ErrorKind::TimedOut)
 - #73495 (Converted all platform-specific stdin/stdout/stderr implementations to use io:: traits)
 - #73575 (Fix typo in error_codes doc)
 - #73578 (Make is_freeze and is_copy_modulo_regions take TyCtxtAt)
 - #73586 (switch_ty is redundant)
 - #73600 (Fix spurious 'value moved here in previous iteration of loop' messages)
 - #73610 (Clean up E0699 explanation)

Failed merges:

r? @ghost
2020-06-23 04:03:28 +00:00
yuqio
9267b4f612 Remove unused crate imports in 2018 edition crates 2020-06-23 05:01:20 +02:00
Dylan DPC
5426586cc3
Rollup merge of #73495 - Lucretiel:wasi-io-impls, r=sfackler
Converted all platform-specific stdin/stdout/stderr implementations to use io:: traits

Currently, some of the platform-specific standard streams (`src/libstd/sys/*/stdio.rs`) manually implement parts of the `io::Write` interface directly as methods on the struct, rather than by actually implementing the trait. There doesn't seem to be any reason for this, other than an unused advantage of `fn write(&self, ...)` instead of `fn write(&mut self, ...)`.

Unfortunately, this means that those implementations don't have the default-implemented io methods, like `read_exact` and `write_all`. This caused #72705, which adds forwarding methods to the user-facing standard stream implementations, to fail to compile on those platforms.

This change converts *all* such standard stream structs to use the standard library traits. This change should not cause any breakages, because the changed types are not publicly exported, and in fact are only ever used in `src/libstd/io/stdio.rs`.
2020-06-23 03:16:19 +02:00
Dylan DPC
6276c135d1
Rollup merge of #71756 - carstenandrich:master, r=dtolnay
add Windows system error codes that should map to io::ErrorKind::TimedOut

closes #71646

**Disclaimer:** The author of this pull request has a negligible amount of experience (i.e., kinda zero) with the Windows API. This PR should _definitely_ be reviewed by someone familiar with the API and its error handling.

While porting POSIX software using serial ports to Windows, I found that for many Windows system error codes, an `io::Error` created via `io::Error::from_raw_os_error()` or `io::Error::last_os_error()` is not `io::ErrorKind::TimedOut`. For example, when a (non-overlapped) write to a COM port via [`WriteFile()`](https://docs.microsoft.com/en-us/windows/win32/api/fileapi/nf-fileapi-readfile) times out, [`GetLastError()`](https://docs.microsoft.com/en-us/windows/win32/api/errhandlingapi/nf-errhandlingapi-getlasterror) returns `ERROR_SEM_TIMEOUT` ([121](https://docs.microsoft.com/en-us/windows/win32/debug/system-error-codes--0-499-)). However, an `io::Error` created from this error code will have `io::ErrorKind::Other`.

Currently, only the error codes `ERROR_OPERATION_ABORTED` and `WSAETIMEDOUT` will instantiate `io::Error`s with kind `io::ErrorKind::TimedOut`.
This makes `io::Error::last_os_error()` unsuitable for error handling of syscalls that could time out, because timeouts can not be caught by matching the error's kind against `io::ErrorKind::TimedOut`.

Downloading the [list of Windows system error codes](https://gist.github.com/carstenandrich/c331d557520b8a0e7f44689ca257f805) and grepping anything that sounds like a timeout (`egrep -i "timed?.?(out|limit)"`), I've identified the following error codes that should also have `io::ErrorKind::TimedOut`, because they could be I/O-related:

Name | Code | Description
--- | --- | ---
`ERROR_SEM_TIMEOUT` | [121](https://docs.microsoft.com/en-us/windows/win32/debug/system-error-codes--0-499-) | The semaphore timeout period has expired.
`WAIT_TIMEOUT` | [258](https://docs.microsoft.com/en-us/windows/win32/debug/system-error-codes--0-499-) | The wait operation timed out.
`ERROR_DRIVER_CANCEL_TIMEOUT` | [594](https://docs.microsoft.com/en-us/windows/win32/debug/system-error-codes--500-999-) | The driver %hs failed to complete a cancelled I/O request in the allotted time.
`ERROR_COUNTER_TIMEOUT` | [1121](https://docs.microsoft.com/en-us/windows/win32/debug/system-error-codes--1000-1299-) | A serial I/O operation completed because the timeout period expired. The IOCTL_SERIAL_XOFF_COUNTER did not reach zero.)
`ERROR_TIMEOUT` | [1460](https://docs.microsoft.com/en-us/windows/win32/debug/system-error-codes--1300-1699-) | This operation returned because the timeout period expired.
`ERROR_CTX_MODEM_RESPONSE_TIMEOUT` | [7012](https://docs.microsoft.com/en-us/windows/win32/debug/system-error-codes--6000-8199-) | The modem did not respond to the command sent to it. Verify that the modem is properly cabled and powered on.
`ERROR_CTX_CLIENT_QUERY_TIMEOUT` | [7040](https://docs.microsoft.com/en-us/windows/win32/debug/system-error-codes--6000-8199-) | The client failed to respond to the server connect message.
`ERROR_DS_TIMELIMIT_EXCEEDED` | [8226](https://docs.microsoft.com/en-us/windows/win32/debug/system-error-codes--8200-8999-) | The time limit for this request was exceeded.
`DNS_ERROR_RECORD_TIMED_OUT` | [9705](https://docs.microsoft.com/en-us/windows/win32/debug/system-error-codes--9000-11999-) | DNS record timed out.
`ERROR_IPSEC_IKE_TIMED_OUT` | [13805](https://docs.microsoft.com/en-us/windows/win32/debug/system-error-codes--12000-15999-) | Negotiation timed out.

The following errors are also timeouts, but they don't seem to be directly related to I/O or network operations:

Name | Code | Description
--- | --- | ---
`ERROR_SERVICE_REQUEST_TIMEOUT` | [1053](https://docs.microsoft.com/en-us/windows/win32/debug/system-error-codes--1000-1299-) | The service did not respond to the start or control request in a timely fashion.
`ERROR_RESOURCE_CALL_TIMED_OUT` | [5910](https://docs.microsoft.com/en-us/windows/win32/debug/system-error-codes--4000-5999-) | The call to the cluster resource DLL timed out.
`FRS_ERR_SYSVOL_POPULATE_TIMEOUT` | [8014](https://docs.microsoft.com/en-us/windows/win32/debug/system-error-codes--6000-8199-) | The file replication service cannot populate the system volume because of an internal timeout. The event log may have more information.
`ERROR_RUNLEVEL_SWITCH_TIMEOUT` | [15402](https://docs.microsoft.com/en-us/windows/win32/debug/system-error-codes--12000-15999-) | The requested run level switch cannot be completed successfully since one or more services will not stop or restart within the specified timeout.
`ERROR_RUNLEVEL_SWITCH_AGENT_TIMEOUT` | [15403](https://docs.microsoft.com/en-us/windows/win32/debug/system-error-codes--12000-15999-) | A run level switch agent did not respond within the specified timeout.

Please note that `ERROR_SEM_TIMEOUT` is the only timeout error I have [seen in action](https://gist.github.com/carstenandrich/10b3962fa1abc9e50816b6460010900b). The remainder of the error codes listed above is based purely on reading documentation.

This pull request adds all of the errors listed in both tables, but I'm not sure whether adding all of them makes sense. Someone with actual Windows API experience should decide that.

I expect these changes to be fairly backwards compatible, because only the error's [`.kind()`](https://doc.rust-lang.org/std/io/struct.Error.html#method.kind) will change, but matching the error's code via [`.raw_os_error()`](https://doc.rust-lang.org/std/io/struct.Error.html#method.raw_os_error) will not be affected.
However, code expecting these errors to be `io::ErrorKind::Other` would break. Even though I personally do not think such an implementation would make sense, after all the docs say that `io::ErrorKind` is _intended to grow over time_, a residual risk remains, of course. I took the liberty to ammend the docstring of `io::ErrorKind::Other` with a remark that discourages matching against it.

As per the contributing guidelines I'm adding @steveklabnik due to the changed documentation. Also @retep998 might have some valuable insights on the error codes.

r? @steveklabnik
cc @retep998
cc @Mark-Simulacrum
2020-06-23 03:16:14 +02:00
bors
dcd470fe1b Auto merge of #73007 - yoshuawuyts:socketaddr-from-string-u16, r=sfackler
impl ToSocketAddrs for (String, u16)

This adds a convenience impl of `ToSocketAddrs for (String, u16)`. When authoring HTTP services it's common to take command line options for `host` and `port` and parse them into `String` and `u16` respectively. Consider the following program:
```rust
#[derive(Debug, StructOpt)]
struct Config {
    host: String,
    port: u16,
}

async fn main() -> io::Result<()> {
    let config = Config::from_args();
    let stream = TcpStream::connect((&*config.host, config.port))?; // &* is not ideal
    // ...
}
```

Networking is a pretty common starting point for people new to Rust, and seeing `&*` in basic examples can be confusing. Even as someone that has experience with networking in Rust I tend to forget that `String` can't be passed directly there. Instead with this patch we can omit the `&*` conversion and pass `host` directly:
```rust
#[derive(Debug, StructOpt)]
struct Config {
    host: String,
    port: u16,
}

async fn main() -> io::Result<()> {
    let config = Config::from_args();
    let stream = TcpStream::connect((config.host, config.port))?; // no more conversions!
    // ...
}
```

I think should be an easy and small ergonomics improvement for networking. Thanks!
2020-06-23 00:13:50 +00:00
Alexis Bourget
3c46e36d39 Document the mut keyword 2020-06-22 16:27:23 +02:00
Alexis Bourget
9766a93163 Document the mod keyword 2020-06-22 15:36:09 +02:00
bors
228a0ed7b0 Auto merge of #70946 - jumbatm:clashing-extern-decl, r=nagisa
Add a lint to catch clashing `extern` fn declarations.

Closes #69390.

Adds lint `clashing_extern_decl` to detect when, within a single crate, an extern function of the same name is declared with different types. Because two symbols of the same name cannot be resolved to two different functions at link time, and one function cannot possibly have two types, a clashing extern declaration is almost certainly a mistake.

This lint does not run between crates because a project may have dependencies which both rely on the same extern function, but declare it in a different (but valid) way. For example, they may both declare an opaque type for one or more of the arguments (which would end up distinct types), or use types that are valid conversions in the language the extern fn is defined in. In these cases, we can't say that the clashing declaration is incorrect.

r? @eddyb
2020-06-21 02:20:07 +00:00
Ralf Jung
96b86ea1a8
Rollup merge of #73471 - raoulstrackx:raoul/fpu_tag_word, r=jethrogb
Prevent attacker from manipulating FPU tag word used in SGX enclave

Insufficient sanitization of the x87 FPU tag word in the trusted enclave runtime allowed unprivileged adversaries in the containing host application to induce incoherent or unexpected results for ABI-compliant compiled enclave application code that uses the x87 FPU.

Vulnerability was disclosed to us by Fritz Alder, Jo Van Bulck, David Oswald and Frank Piessens

cc: @jethrogb
2020-06-20 16:39:57 +02:00
Ralf Jung
77efcab0f2
Rollup merge of #73171 - tblah:riscv-qemu-test, r=pietroalbini
RISC-V Emulated Testing

Adds a disabled docker image on which to run RISC-V tests. Based on the armhf image.

Test using
```
./src/ci/docker/run.sh riscv64gc-linux
```

cc: @msizanoen1
2020-06-20 16:39:51 +02:00
jumbatm
6b74e3cbb9 Add ClashingExternDecl lint.
This lint checks that all declarations for extern fns of the same name
are declared with the same types.
2020-06-20 16:54:32 +10:00
Manish Goregaokar
7777b0b03d
Rollup merge of #73484 - poliorcetics:use-prelude-doc, r=sfackler
Update the doc for std::prelude to the correct behavior

Fixes #64686.

One line change to ensure the docs are correct about the behavior of the compiler when inserting`std::prelude::v1`.

I don't think examples are necessary but I can add some (especially those from the original issue) if needed.
2020-06-19 19:43:11 -07:00
Alexis Bourget
8f0bd5ffe6 Update the doc for std::prelude, removing the "technical part" section 2020-06-19 21:19:17 +02:00
Raoul Strackx
33b304c5e0 Using xsave restore to restore complete FPU state 2020-06-19 18:39:07 +02:00
Nathan West
0094f44a0b Remove old commented code 2020-06-19 11:42:58 -04:00
Nathan West
e93362b974 Fixed missing mut 2020-06-19 11:32:36 -04:00
Ralf Jung
f7d833e83d
Rollup merge of #73464 - qy3u:fs-document-format-correction, r=jonas-schievink
Document format correction

Minor amendments to the document.

r? @steveklabnik
2020-06-19 08:56:17 +02:00