bors [Thu, 1 Oct 2020 13:21:34 +0000 (13:21 +0000)]
Auto merge of #76919 - fusion-engineering-forks:thread-parker, r=dtolnay
Use futex-based thread::park/unpark on Linux.
This moves the parking/unparking logic out of `thread/mod.rs` into a module named `thread_parker` in `sys_common`. The current implementation is moved to `sys_common/thread_parker/generic.rs` and the new implementation using futexes is added in `sys_common/thread_parker/futex.rs`.
bors [Thu, 1 Oct 2020 07:38:47 +0000 (07:38 +0000)]
Auto merge of #77354 - ecstatic-morse:const-checking-moar-errors, r=oli-obk
Overhaul const-checking diagnostics
The primary purpose of this PR was to remove `NonConstOp::STOPS_CONST_CHECKING`, which causes any additional errors found by the const-checker to be silenced. I used this flag to preserve diagnostic parity with `qualify_min_const_fn.rs`, which has since been removed.
However, simply removing the flag caused a deluge of errors in some cases, since an error would be emitted any time a local or temporary had a wrong type. To remedy this, I added an alternative system (`DiagnosticImportance`) to silence additional error messages that were likely to distract the user from the underlying issue. When an error of the highest importance occurs, all less important errors are silenced. When no error of the highest importance occurs, all less important errors are emitted after checking is complete. Following the suggestions from the important error is usually enough to fix the less important errors, so this should lead to better UX most of the time.
There's also some unrelated diagnostics improvements in this PR isolated in their own commits. Splitting them out would be possible, but a bit of a pain. This isn't as tidy as some of my other PRs, but it should *only* affect diagnostics, never whether or not something passes const-checking. Note that there are a few trivial exceptions to this, like banning `Yield` in all const-contexts, not just `const fn`.
Dylan DPC [Thu, 1 Oct 2020 00:13:41 +0000 (02:13 +0200)]
Rollup merge of #77319 - tgnottingham:siphasher_endianness, r=nnethercote
Stable hashing: add comments and tests concerning platform-independence
SipHasher128 implements short_write in an endian-independent way, yet
its write_xxx Hasher trait methods undo this endian-independence by byte
swapping the integer inputs on big-endian hardware. StableHasher then
adds endian-independence back by also byte-swapping on big-endian
hardware prior to invoking SipHasher128.
This double swap may have the appearance of being a no-op, but is in
fact by design. In particular, we really do want SipHasher128 to be
platform-dependent, in order to be consistent with the libstd SipHasher.
Try to clarify this intent. Also, add and update a couple of unit tests.
~StableHasher is supposed to ensure platform independence by converting
integers to little-endian and extending isize and usize to 64 bits as
necessary, but in fact, much of that work is already handled by
SipHasher128.~
~In particular, SipHasher128 implements short_write in an
endian-independent way, yet both StableHasher and SipHasher128
additionally attempt to achieve endian-independence by byte swapping on
BE hardware before invoking short writes. This double swap has no
effect, so let's remove it.~
~Because short_write is endian-independent, SipHasher128 is already
handling part of the platform-independence, and it would be somewhat
difficult to make it *not* handle that part with the current
implementation. As splitting platform-independence responsibilities
between StableHasher and SipHasher128 would be confusing, let's make
SipHasher128 handle all of it.~
~Finally, update some incorrect comments and increase test coverage.
Unit tests pass on both LE and BE systems.~
Dylan DPC [Thu, 1 Oct 2020 00:13:35 +0000 (02:13 +0200)]
Rollup merge of #77303 - lcnr:const-evaluatable-TooGeneric, r=oli-obk,varkor
const evaluatable: improve `TooGeneric` handling
Instead of emitting an error in `fulfill`, we now correctly stall on inference variables.
As `const_eval_resolve` returns `ErrorHandled::TooGeneric` when encountering generic parameters on which
we actually do want to error, we check for inference variables and eagerly emit an error if they don't exist, returning `ErrorHandled::Reported` instead.
Also contains a small bugfix for `ConstEquate` where we previously only stalled on type variables. This is probably a leftover from
when we did not yet support stalling on const inference variables.
Dylan DPC [Thu, 1 Oct 2020 00:13:34 +0000 (02:13 +0200)]
Rollup merge of #77202 - ehuss:defer-apple-sdkroot, r=petrochenkov
Defer Apple SDKROOT detection to link time.
This defers the detection of the SDKROOT for Apple iOS/tvOS targets to link time, instead of when the `Target` is defined. This allows commands that don't need to link to work (like `rustdoc` or `rustc --print=target-list`). This also makes `--print=target-list` a bit faster.
This also removes the note in the platform support documentation about these targets being missing. When I wrote it, I misunderstood how the SDKROOT stuff worked.
Notes:
* This means that JSON spec targets can't explicitly override these flags. I think that is probably fine, as I believe the value is generally required, and can be set with the SDKROOT environment variable.
* This changes `x86_64-apple-tvos` to use `appletvsimulator`. I think the original code was wrong (it was using `iphonesimulator`). Also, `x86_64-apple-tvos` seems broken in general, and I cannot build it locally. The `data_layout` does not appear to be correct (it is a copy of the arm64 layout instead of the x86_64 layout). I have not tried building Apple's LLVM to see if that helps, but I suspect it is just wrong (I'm uncertain since I don't know how the tvOS simulator works with its bitcode-only requirements).
* I'm tempted to remove the use of `Result` for built-in target definitions, since I don't think they should be fallible. This was added in https://github.com/rust-lang/rust/pull/34980, but that only relates to JSON definitions. I think the built-in targets shouldn't fail. I can do this now, or not.
Dylan DPC [Thu, 1 Oct 2020 00:13:32 +0000 (02:13 +0200)]
Rollup merge of #77153 - Aaron1011:fix/better-recursive-expand, r=petrochenkov
Fix recursive nonterminal expansion during pretty-print/reparse check
Makes progress towards #43081
In PR #73084, we started recursively expanded nonterminals during the
pretty-print/reparse check, allowing them to be properly compared
against the reparsed tokenstream.
Unfortunately, the recursive logic in that PR only handles the case
where a nonterminal appears inside a `TokenTree::Delimited`. If a
nonterminal appears directly in the expanded tokens of another
nonterminal, the inner nonterminal will not be expanded.
This PR fixes the recursive expansion of nonterminals, ensuring that
they are expanded wherever they occur.
that advances the iterator by `n` elements, returning `Ok(())` if this succeeds or `Err(len)` if the length of the iterator was less than `n`.
Currently `Iterator::nth` is the method to override for efficiently advancing an iterator by multiple elements at once. `advance_by` is superior for this purpose because
- it's simpler to implement: instead of advancing the iterator and producing the next element you only need to advance the iterator
- it composes better: iterators like `Chain` and `FlatMap` can implement `advance_by` in terms of `advance_by` on their inner iterators, but they cannot implement `nth` in terms of `nth` on their inner iterators (see #60395)
- the default implementation of `nth` can trivially be implemented in terms of `advance_by` and `next`, which this PR also does
This PR also adds `DoubleEndedIterator::advance_back_by` for all the same reasons.
I'll make a tracking issue if it's decided this is worth merging. Also let me know if anything can be improved, this went through several iterations so there might very well still be room for improvement (especially in the doc comments). I've written overrides of these methods for most iterators that already override `nth`/`nth_back`, but those still need tests so I'll add them in a later PR.
Auto merge of #76325 - lzutao:split-core-str, r=Amanieu
Split core/str/mod.rs to smaller files
Note for reviewer:
* I split to multiple commits for easier reviewing, but I could git squash them all to one if requested.
* Recommend pulling this change locally and using advanced git diff viewer or this command:
```bash
git show --reverse --color-moved=dimmed-zebra --color-moved-ws=ignore-all-space master..
```
---
I split `core/str/mod.rs` to these modules:
* `converts`: Contains helper functions to convert from bytes to str.
* `error`: For error structs like Utf8Error.
* `iter`: For iterators of many str methods.
* `traits`: For indexing operations and build in traits on str.
* `validations`: For functions validating utf8 --- This name is awkward, maybe utf8.rs is better.
Auto merge of #77372 - jonas-schievink:rollup-e5bdzga, r=jonas-schievink
Rollup of 12 pull requests
Successful merges:
- #77037 (more tiny clippy cleanups)
- #77233 (BTreeMap: keep an eye out on the size of the main components)
- #77280 (Ensure that all LLVM components requested by tests are available on CI)
- #77284 (library: Forward compiler-builtins "mem" feature)
- #77296 (liveness: Use Option::None to represent absent live nodes)
- #77322 (Add unstable book docs for `-Zunsound-mir-opts`)
- #77328 (Use `rtassert!` instead of `assert!` from the child process after fork() in std::sys::unix::process::Command::spawn())
- #77331 (Add test for async/await combined with const-generics.)
- #77338 (Fix typo in alloc vec comment)
- #77340 (Alloc vec use imported path)
- #77345 (Add test for issue #74761)
- #77348 (Update books)
Jonas Schievink [Wed, 30 Sep 2020 18:56:24 +0000 (20:56 +0200)]
Rollup merge of #77348 - ehuss:update-books, r=ehuss
Update books
## rust-by-example
5 commits in 19f0a0372af497b34369cf182d9d16156cab2969..7d3ff1c12db08a847a57a054be4a7951ce532d2d
2020-08-26 09:38:48 -0300 to 2020-09-28 15:54:25 -0300
- Prevent duplicated error information in "wrapping errors" example (rust-lang/rust-by-example#1375)
- Avoid lifetime annotation in struct example (rust-lang/rust-by-example#1378)
- Clone.md comment and variable name change (rust-lang/rust-by-example#1379)
- Replace panic example with a simpler version (rust-lang/rust-by-example#1380)
- Prefer `const` over `static` (rust-lang/rust-by-example#1381)
Jonas Schievink [Wed, 30 Sep 2020 18:56:10 +0000 (20:56 +0200)]
Rollup merge of #77284 - josephlr:mem, r=Mark-Simulacrum
library: Forward compiler-builtins "mem" feature
This fixes https://github.com/rust-lang/wg-cargo-std-aware/issues/53
Now users will be able to do:
```
cargo build -Zbuild-std=core -Zbuild-std-features=compiler-builtins-mem
```
and correctly get the Rust implemenations for `memcpy` and friends.
I used an environment variable because passing a command line option all the way from CI to compiletest would be just too much hassle for this task.
I added a new variable, but any of the already existing ones defined by CI could be used instead.
r? @Mark-Simulacrum
Auto merge of #75810 - hug-dev:cmse-nonsecure-entry, r=jonas-schievink
Add support for cmse_nonsecure_entry attribute
This pull request adds the `cmse_nonsecure_entry` attribute under an unstable feature.
I was not sure if it was fine for me to send directly the pull-request or if I should submit a RFC first. I was told on Zulip that it was fine to do so but please close it if I need first submit a RFC or follow another process instead.
The `cmse_nonsecure_entry` attribute is a LLVM attribute that will be available in LLVM 11. I plan to rebase on the [upgrade PR](https://github.com/rust-lang/rust/pull/73526) once merged to make this one compile.
This attribute modifies code generation of the function as explained [here](https://developer.arm.com/documentation/ecm0359818/latest/) to make it work with the TrustZone-M hardware feature. This feature is only available on `thumbv8m` targets so I created an error for that if one tries to use this attribute for another target.
I added this attribute in Rust as any other LLVM attribute are added but since this one is target-dependent I am not sure if it was the best thing to do. Please indicate me if you think of other ways, like isolating target-dependent attributes together.
Auto merge of #77298 - jyn514:bootstrap-config, r=Mark-Simulacrum
Don't warn if the config file is somewhere other than `config.toml`
Previously, `config.config` was always hardcoded as `"config.toml"`.
I thought that it was being overridden with the actual value later, but
it turns out `flags.config` was being completely discarded. This keeps
`config.config` in sync with `flags.config`.
Fixes https://github.com/rust-lang/rust/issues/77293
r? `@Mark-Simulacrum`
cc `@davidtwco`
Hugues de Valon [Mon, 28 Sep 2020 20:10:38 +0000 (21:10 +0100)]
Add support for cmse_nonsecure_entry attribute
This patch adds support for the LLVM cmse_nonsecure_entry attribute.
This is a target-dependent attribute that only has sense for the
thumbv8m Rust targets.
You can find more information about this attribute here:
https://developer.arm.com/documentation/ecm0359818/latest/
Signed-off-by: Hugues de Valon <hugues.devalon@arm.com>
Hugues de Valon [Tue, 29 Sep 2020 11:20:56 +0000 (12:20 +0100)]
Update LLVM and add Unsupported diagnostic
Secure entry functions do not support if arguments are passed on the
stack. An "unsupported" diagnostic will be emitted by LLVM if that is
the case.
This commits adds support in Rust for that diagnostic so that an error
will be output if that is the case!
Signed-off-by: Hugues de Valon <hugues.devalon@arm.com>
Stable hashing: add comments and tests concerning platform-independence
SipHasher128 implements short_write in an endian-independent way, yet
its write_xxx Hasher trait methods undo this endian-independence by byte
swapping the integer inputs on big-endian hardware. StableHasher then
adds endian-independence back by also byte-swapping on big-endian
hardware prior to invoking SipHasher128.
This double swap may have the appearance of being a no-op, but is in
fact by design. In particular, we really do want SipHasher128 to be
platform-dependent, in order to be consistent with the libstd SipHasher.
Try to clarify this intent. Also, add and update a couple of unit tests.
Similar to the change in #76669 but all `llvm_asm!` is gate in x86/x86_64 target.
Godbolt:
- https://rust.godbolt.org/z/h7nG1h
- https://rust.godbolt.org/z/xx39hW
This helper function was meant to reduce code duplication between
const-checking pre- and post-drop-elaboration. Most of the functionality
is only relevant for the pre-drop-elaboration pass.
Auto merge of #77274 - tmiasko:liveness-cnd, r=lcnr
Liveness refactoring continued
* Move body_owner field from IrMaps to Liveness (the only user of the field).
* Use upvars instead of FnKind to check for closures (avoids FnKind, will be useful when checking all bodies, not just fns).
* Use visit_param to add variables corresponding to params.
* Store upvars_mentioned inside Liveness struct.
* Inline visitor implementation for IrMaps, avoiding unnecessary indirection.
* Test interaction with automatically_derived attribute (not covered by any of existing tests).
Auto merge of #77145 - pietroalbini:refactor-build-manifest-versions, r=Mark-Simulacrum
Refactor versions detection in build-manifest
This PR refactors how `build-manifest` handles versions, making the following changes:
* `build-manifest` now detects the "package releases" on its own, without relying on rustbuild providing them through CLI arguments. This drastically simplifies calling the tool outside of `x.py`, and will allow to ship the prebuilt tool in a tarball in the future, with the goal of stopping to invoke `x.py` during `promote-release`.
* The `tar` command is not used to extract the version and the git hash from tarballs anymore. The `flate2` and `tar` crates are used instead. This makes detecting those pieces of data way faster, as the archive is decompressed just once and we stop parsing the archive once all the information is retrieved.
* The code to extract the version and the git hash now stores all the collected data dynamically, without requiring to add new fields to the `Builder` struct every time.
I tested the changes locally and it should behave the same as before.
Auto merge of #77253 - jyn514:crate-link, r=Manishearth
Resolve `crate` in intra-doc links properly across crates
Closes https://github.com/rust-lang/rust/issues/77193; see https://github.com/rust-lang/rust/issues/77193#issuecomment-699065946 for an explanation of what's going on here.
~~This also fixes the BTreeMap docs that have been broken for a while; see the description on the second commit for why and how.~~ Nope, see the second commit for why the link had to be changed.
r? `@Manishearth`
cc `@dylni`
`@dylni` note that this doesn't solve your original problem - now _both_ `with_code` and `crate::with_code` will be broken links. However this will fix a lot of other broken links (in particular I think https://docs.rs/sqlx/0.4.0-beta.1/sqlx/query/struct.Query.html is because of this bug). I'll open another issue for resolving additional docs in the new scope.
Auto merge of #77275 - petrochenkov:interpid, r=varkor
expand: Stop normalizing `NtIdent`s before passing them to built-in macros
Built-in macros should be able to deal with `NtIdents` in the input by themselves like any other parser code.
You can't imagine how bad mutable AST visitors are, *especially* if they are modifying tokens.
This is one step towards removing token visiting from the visitor infrastructure (https://github.com/rust-lang/rust/pull/77271 also works in this direction.)
Auto merge of #77257 - ecstatic-morse:optimize-int-range-from-pat, r=Mark-Simulacrum
Optimize `IntRange::from_pat`, then shrink `ParamEnv`
Resolves #77058.
r? `@Mark-Simulacrum`
cc `@vandenheuvel`
Looking at the output of `perf report` for #76244, the hot instructions seemed to be around the call to `pat_constructor` in `IntRange::from_pat`. I carried out an obvious optimization, but it actually made the instruction count higher (see #77075). However, it seems to have mitigated whatever was causing the pipeline stalls, so when combined with #76244, it's a net win.
As you can see below, the regression in #76244 seems to have originated from something measured by `stalled-cycles-backend`. I'll try to collect some finer-grained stats to see if I can isolate it. I wish I had a better idea of what was going on here. I'd like to prevent the regression from reappearing in the future due to small changes in unrelated code.
<details>
<summary>Current `master`:</summary>
```
Performance counter stats for 'cargo +baseline-stage1 check':
projects / rust.git / log