Niko Matsakis [Wed, 15 Jun 2022 12:46:19 +0000 (08:46 -0400)]
generalize the outlives obligation code
The code now accepts `Binder<OutlivesPredicate>`
instead of just `OutlivesPredicate` and thus exercises
the new, generalized `IfEqBound` codepaths. Note though
that we never *produce* Binder<OutlivesPredicate>, so we
are only testing a subset of those codepaths that excludes
actual higher-ranked outlives bounds.
bors [Tue, 14 Jun 2022 17:19:38 +0000 (17:19 +0000)]
Auto merge of #96591 - b-naber:transition-to-valtrees-in-type-system, r=lcnr
Use valtrees as the type-system representation for constant values
This is not quite ready yet, there are still some problems with pretty printing and symbol mangling and `deref_const` seems to not work correctly in all cases.
Mainly opening now for a perf-run (which should be good to go, despite the still existing problems).
*Note: this is a companion to https://github.com/rust-lang/measureme/pull/143, and duplicates some information with it for convenience*
**(much later) EDIT**: take any numbers with a grain of salt, they may have changed since initial PR open.
## Credits
I'd like to start by thanking `@alyssais,` `@cuviper,` `@edef1c,` `@glandium,` `@jix,` `@Mark-Simulacrum,` `@m-ou-se,` `@mystor,` `@nagisa,` `@puckipedia,` and `@yorickvP,` for all of their help with testing, and valuable insight and suggestions.
Getting here wouldn't have been possible without you!
(If I've forgotten anyone please let me know, I'm going off memory here, plus some discussion logs)
## Summary
This PR adds support to `-Z self-profile` for counting hardware events such as "instructions retired" (as opposed to being limited to time measurements), using the `rdpmc` instruction on `x86_64` Linux.
While other OSes may eventually be supported, preliminary research suggests some kind of kernel extension/driver is required to enable this, whereas on Linux any user can profile (at least) their own threads.
Supporting Linux on architectures other than x86_64 should be much easier (provided the hardware supports such performance counters), and was mostly not done due to a lack of readily available test hardware.
That said, 32-bit `x86` (aka `i686`) would be almost trivial to add and test once we land the initial `x86_64` version (as all the CPU detection code can be reused).
A new flag `-Z self-profile-counter` was added, to control which of the named `measureme` counters is used, and which defaults to `wall-time`, in order to keep `-Z self-profile`'s current functionality unchanged (at least for now).
The named counters so far are:
* `wall-time`: the existing time measurement
* name chosen for consistency with `perf.rust-lang.org`
* continues to use `std::time::Instant` for a nanosecond-precision "monotonic clock"
* `instructions:u`: the hardware performance counter usually referred to as "Instructions retired"
* here "retired" (roughly) means "fully executed"
* the `:u` suffix is from the Linux `perf` tool and indicates the counter only runs while userspace code is executing, and therefore counts no kernel instructions
* *see [Caveats/Subtracting IRQs](https://hackmd.io/sH315lO2RuicY-SEt7ynGA?view#Subtracting-IRQs) for why this isn't entirely true and why `instructions-minus-irqs:u` should be preferred instead*
* `instructions-minus-irqs:u`: same as `instructions:u`, except the count of hardware interrupts ("IRQs" here for brevity) is subtracted
* *see [Caveats/Subtracting IRQs](https://hackmd.io/sH315lO2RuicY-SEt7ynGA?view#Subtracting-IRQs) for why this should be preferred over `instructions:u`*
* `instructions-minus-r0420:u`: experimental counter, same as `instructions-minus-irqs:u` but subtracting an undocumented counter (`r0420:u`) instead of IRQs
* the `rXXXX` notation is again from Linux `perf`, and indicates a "raw" counter, with a hex representation of the low-level counter configuration - this was picked because we still don't *really* know what it is
* this only exists for (future) testing and isn't included/used in any comparisons/data we've put together so far
* *see [Challenges/Zen's undocumented 420 counter](https://hackmd.io/sH315lO2RuicY-SEt7ynGA?view#Epilogue-Zen’s-undocumented-420-counter) for details on how this counter was found and what it does*
---
There are also some additional commits:
* ~~see [Challenges/Rebasing *shouldn't* affect the results, right?](https://hackmd.io/sH315lO2RuicY-SEt7ynGA?view#Rebasing-*shouldn’t*-affect-the-results,-right) for details on the changes to `rustc_parse` and `rustc_trait_section` (the latter far more dubious, and probably shouldn't be merged, or not as-is)~~
* **EDIT**: the effects of these are no long quantifiable, the PR includes reverts for them
* ~~see [Challenges/`jemalloc`: purging will commence in ten seconds](https://hackmd.io/sH315lO2RuicY-SEt7ynGA?view#jemalloc-purging-will-commence-in-ten-seconds) for details on the `jemalloc` change~~
* this is also separately found in #77162, and we probably want to avoid doing it by default, ideally we'd use the runtime control API `jemalloc` offers (assuming that can stop the timer that's already running, which I'm not sure about)
* **EDIT**: until we can do this based on `-Z` flags, this commit has also been reverted
* the `proc_macro` change was to avoid randomized hashing and therefore ASLR-like effects
---
**(much later) EDIT**: take any numbers with a grain of salt, they may have changed since initial PR open.
#### Write-up / report
Because of how extensive the full report ended up being, I've kept most of it [on `hackmd.io`](https://hackmd.io/sH315lO2RuicY-SEt7ynGA?view), but for convenient access, here are all the sections (with individual links):
<sup>(someone suggested I'd make a backup, so [here it is on the wayback machine](http://web.archive.org/web/20201127164748/https://hackmd.io/sH315lO2RuicY-SEt7ynGA?view) - I'll need to remember to update that if I have to edit the write-up)</sup>
* [**Results**](https://hackmd.io/sH315lO2RuicY-SEt7ynGA?view#Results)
* [**Overhead**](https://hackmd.io/sH315lO2RuicY-SEt7ynGA?view#Overhead)
*Preview (see the report itself for more details):*
|Counter|Total<br>`instructions-minus-irqs:u`|Overhead from "Baseline"<br>(for all 1903881<br>counter reads)|Overhead from "Baseline"<br>(per each counter read)|
|-|-|-|-|
|Baseline|63637621286 ±6||
|`instructions:u`|63658815885 ±2| +21194599 ±8| +11|
|`instructions-minus-irqs:u`|63680307361 ±13| +42686075 ±19| +22|
|`wall-time`|63951958376 ±10275|+314337090 ±10281|+165|
* [**"Macro" noise (self time)**](https://hackmd.io/sH315lO2RuicY-SEt7ynGA?view#“Macro”-noise-(self-time))
*Preview (see the report itself for more details):*
Dylan DPC [Tue, 14 Jun 2022 08:35:33 +0000 (10:35 +0200)]
Rollup merge of #98069 - notriddle:notriddle/square-brackets, r=jsha
rustdoc: remove link on slice brackets
This is #91778, take two.
Fixes #91173
The reason I'm reevaluating this change is #97668, which makes fully-generic slices link to the slice docs page. This fixes some downsides in the original PR, where `Box<[T]>`, for example, was not linked to the primitive.slice.html page. In this PR, the `[T]` inside is still a link.
The other major reason for wanting to reevaluate this is the changed color scheme. When this feature was first introduced in rustdoc, primitives were a different color from structs and enums. This way, eagle-eyed users could figure out that the square brackets were separate links from the structs inside. Now, all types have the same color, so a significant fraction of users won't even know the links are there unless they pay close attention to the status bar or use an accessibility tool that lists all links on the page.
Dylan DPC [Tue, 14 Jun 2022 08:35:31 +0000 (10:35 +0200)]
Rollup merge of #97948 - davidtwco:diagnostic-translation-lints, r=oli-obk
lint: add diagnostic translation migration lints
Introduce allow-by-default lints for checking whether diagnostics are written in
`SessionDiagnostic` or `AddSubdiagnostic` impls and whether diagnostics are translatable. These lints can be denied for modules once they are fully migrated to impls and translation.
These lints are intended to be temporary - once all diagnostics have been changed then we can just change the APIs we have and that will enforce these constraints thereafter.
Dylan DPC [Tue, 14 Jun 2022 08:35:29 +0000 (10:35 +0200)]
Rollup merge of #97935 - nnethercote:rename-ConstS-val-as-kind, r=lcnr
Rename the `ConstS::val` field as `kind`.
And likewise for the `Const::val` method.
Because its type is called `ConstKind`. Also `val` is a confusing name
because `ConstKind` is an enum with seven variants, one of which is
called `Value`. Also, this gives consistency with `TyS` and `PredicateS`
which have `kind` fields.
The commit also renames a few `Const` variables from `val` to `c`, to
avoid confusion with the `ConstKind::Value` variant.
Because its type is called `ConstKind`. Also `val` is a confusing name
because `ConstKind` is an enum with seven variants, one of which is
called `Value`. Also, this gives consistency with `TyS` and `PredicateS`
which have `kind` fields.
The commit also renames a few `Const` variables from `val` to `c`, to
avoid confusion with the `ConstKind::Value` variant.
Yuki Okushi [Mon, 13 Jun 2022 22:47:25 +0000 (07:47 +0900)]
Rollup merge of #97508 - JohnTitor:more-strict-placeholder-dyn-obj, r=pnkfelix
Harden bad placeholder checks on statics/consts
Resubmission of #89161
Fixes https://github.com/rust-lang/rust/issues/88643
In #83739, I added a check for trait objects on statics/consts but it wasn't robust. `is_suggestable_infer_ty` fn does a more strict check and finds more bad placeholders. See https://github.com/rust-lang/rust/pull/89161#issuecomment-934690300 for the more detailed explanation.
r? `@pnkfelix` as you're the reviewer of the previous PR
Yuki Okushi [Mon, 13 Jun 2022 22:47:24 +0000 (07:47 +0900)]
Rollup merge of #97385 - oli-obk:smir-tool-lib, r=pnkfelix
Add WIP stable MIR crate
r? ``@pnkfelix``
Discussion about this happend in the SMIR meeting yesterday. Some info can be found at https://rust-lang.zulipchat.com/#narrow/stream/320896-project-stable-mir/topic/dev.20plan.20mtg/near/283774691
Yuki Okushi [Mon, 13 Jun 2022 22:47:23 +0000 (07:47 +0900)]
Rollup merge of #95243 - vladimir-ea:compiler_watch_os, r=nagisa
Add Apple WatchOS compile targets
Hello,
I would like to add the following target triples for Apple WatchOS as Tier 3 platforms:
armv7k-apple-watchos
arm64_32-apple-watchos
x86_64-apple-watchos-sim
There are some pre-requisites Pull Requests:
https://github.com/rust-lang/compiler-builtins/pull/456 (merged)
https://github.com/alexcrichton/cc-rs/pull/662 (pending)
https://github.com/rust-lang/libc/pull/2717 (merged)
There will be a subsequent PR with standard library changes for WatchOS. Previous compiler and library changes were in a single PR (https://github.com/rust-lang/rust/pull/94736) which is now closed in favour of separate PRs.
Many thanks!
Vlad.
### Tier 3 Target Requirements
Adds support for Apple WatchOS compile targets.
Below are details on how this target meets the requirements for tier 3:
> tier 3 target must have a designated developer or developers (the "target maintainers") on record to be CCed when issues arise regarding the target. (The mechanism to track and CC such developers may evolve over time.)
`@deg4uss3r` has volunteered to be the target maintainer. I am also happy to help if a second maintainer is required.
> Targets must use naming consistent with any existing targets; for instance, a target for the same CPU or OS as an existing Rust target should use the same name for that CPU or OS. Targets should normally use the same names and naming conventions as used elsewhere in the broader ecosystem beyond Rust (such as in other toolchains), unless they have a very good reason to diverge. Changing the name of a target can be highly disruptive, especially once the target reaches a higher tier, so getting the name right is important even for a tier 3 target.
Uses the same naming as the LLVM target, and the same convention as other Apple targets.
> Target names should not introduce undue confusion or ambiguity unless absolutely necessary to maintain ecosystem compatibility. For example, if the name of the target makes people extremely likely to form incorrect beliefs about what it targets, the name should be changed or augmented to disambiguate it.
I don't believe there is any ambiguity here.
> Tier 3 targets may have unusual requirements to build or use, but must not create legal issues or impose onerous legal terms for the Rust project or for Rust developers or users.
I don't see any legal issues here.
> The target must not introduce license incompatibilities.
> Anything added to the Rust repository must be under the standard Rust license (MIT OR Apache-2.0).
> The target must not cause the Rust tools or libraries built for any other host (even when supporting cross-compilation to the target) to depend on any new dependency less permissive than the Rust licensing policy. This applies whether the dependency is a Rust crate that would require adding new license exceptions (as specified by the tidy tool in the rust-lang/rust repository), or whether the dependency is a native library or binary. In other words, the introduction of the target must not cause a user installing or running a version of Rust or the Rust tools to be subject to any new license requirements.
> If the target supports building host tools (such as rustc or cargo), those host tools must not depend on proprietary (non-FOSS) libraries, other than ordinary runtime libraries supplied by the platform and commonly used by other binaries built for the target. For instance, rustc built for the target may depend on a common proprietary C runtime library or console output library, but must not depend on a proprietary code generation library or code optimization library. Rust's license permits such combinations, but the Rust project has no interest in maintaining such combinations within the scope of Rust itself, even at tier 3.
> Targets should not require proprietary (non-FOSS) components to link a functional binary or library.
> "onerous" here is an intentionally subjective term. At a minimum, "onerous" legal/licensing terms include but are not limited to: non-disclosure requirements, non-compete requirements, contributor license agreements (CLAs) or equivalent, "non-commercial"/"research-only"/etc terms, requirements conditional on the employer or employment of any particular Rust developers, revocable terms, any requirements that create liability for the Rust project or its developers or users, or any requirements that adversely affect the livelihood or prospects of the Rust project or its developers or users.
I see no issues with any of the above.
> Neither this policy nor any decisions made regarding targets shall create any binding agreement or estoppel by any party. If any member of an approving Rust team serves as one of the maintainers of a target, or has any legal or employment requirement (explicit or implicit) that might affect their decisions regarding a target, they must recuse themselves from any approval decisions regarding the target's tier status, though they may otherwise participate in discussions.
> This requirement does not prevent part or all of this policy from being cited in an explicit contract or work agreement (e.g. to implement or maintain support for a target). This requirement exists to ensure that a developer or team responsible for reviewing and approving a target does not face any legal threats or obligations that would prevent them from freely exercising their judgment in such approval, even if such judgment involves subjective matters or goes beyond the letter of these requirements.
Only relevant to those making approval decisions.
> Tier 3 targets should attempt to implement as much of the standard libraries as possible and appropriate (core for most targets, alloc for targets that can support dynamic memory allocation, std for targets with an operating system or equivalent layer of system-provided functionality), but may leave some code unimplemented (either unavailable or stubbed out as appropriate), whether because the target makes it impossible to implement or challenging to implement. The authors of pull requests are not obligated to avoid calling any portions of the standard library on the basis of a tier 3 target not implementing those portions.
core and alloc can be used. std support will be added in a subsequent PR.
> The target must provide documentation for the Rust community explaining how to build for the target, using cross-compilation if possible. If the target supports running tests (even if they do not pass), the documentation must explain how to run tests for the target, using emulation if possible or dedicated hardware if necessary.
Use --target=<target> option to cross compile, just like any target. Tests can be run using the WatchOS simulator (see https://developer.apple.com/documentation/xcode/running-your-app-in-the-simulator-or-on-a-device).
> Tier 3 targets must not impose burden on the authors of pull requests, or other developers in the community, to maintain the target. In particular, do not post comments (automated or manual) on a PR that derail or suggest a block on the PR based on a tier 3 target. Do not send automated messages or notifications (via any medium, including via `@)` to a PR author or others involved with a PR regarding a tier 3 target, unless they have opted into such messages.
> Backlinks such as those generated by the issue/PR tracker when linking to an issue or PR are not considered a violation of this policy, within reason. However, such messages (even on a separate repository) must not generate notifications to anyone involved with a PR who has not requested such notifications.
I don't foresee this being a problem.
> Patches adding or updating tier 3 targets must not break any existing tier 2 or tier 1 target, and must not knowingly break another tier 3 target without approval of either the compiler team or the maintainers of the other tier 3 target.
> In particular, this may come up when working on closely related targets, such as variations of the same architecture with different features. Avoid introducing unconditional uses of features that another variation of the target may not have; use conditional compilation or runtime detection, as appropriate, to let each target run code supported by that target.
No other targets should be affected by the pull request.
Yuki Okushi [Mon, 13 Jun 2022 22:47:22 +0000 (07:47 +0900)]
Rollup merge of #95211 - terrarier2111:improve-parser, r=compiler-errors
Improve parser diagnostics
This pr fixes https://github.com/rust-lang/rust/issues/93867 and contains a couple of diagnostics related changes to the parser.
Here is a short list with some of the changes:
- don't suggest the same thing that is the current token
- suggest removing the current token if the following token is one of the suggestions (maybe incorrect)
- tell the user to put a type or lifetime after where if there is none (as a warning)
- reduce the amount of tokens suggested (via the new eat_noexpect and check_noexpect methods)
If any of these changes are undesirable, i can remove them, thanks!
That whole thing, `[T]`, is a single link to `primitive.slice.html`. This
definitely fixes it for this case, but it's not obvious what we should do for
slices of concrete types:
There are actually three links in that `[u8]`: the opening brace `[` is a
link to `primitive.slice.html`, the `u8` is a link to `primitive.u8.html`,
and the final `]` is a link to `primitive.slice.html`. This is a serious
[usability bug](https://usability.yale.edu/web-accessibility/articles/links):
the square braces are much too small for anyone who doesn't have perfect
motor control using mouse or touch, provide an excessive number of tab stops
for anyone using keyboard, and no visual indication whatsoever that they're
separate links.
Now that slices of generic types are linked, it seems reasonable to err on
the side of less clutter and stop linking concrete slices to the slice page.
bors [Mon, 13 Jun 2022 19:36:41 +0000 (19:36 +0000)]
Auto merge of #98066 - matthiaskrgr:rollup-wb9gs92, r=matthiaskrgr
Rollup of 10 pull requests
Successful merges:
- #97709 (Normalize consts' tys when relating with `adt_const_params`)
- #97875 (Remove the `infer_static_outlives_requirements` feature)
- #97960 (interpret: unify offset_from check with offset check)
- #97999 (Make `type_changing_struct_update` no longer an incomplete feature)
- #98043 (Remove unnecessary `to_string` and `String::new`)
- #98044 ([issues:97981] del unrelated comment)
- #98049 (Document an edge case of `str::split_once`)
- #98050 (Add some more regression tests for #67945)
- #98054 (Fix error message for `download-ci-llvm`)
- #98057 (Update miri)
Matthias Krüger [Mon, 13 Jun 2022 19:35:58 +0000 (21:35 +0200)]
Rollup merge of #98050 - JohnTitor:issue-67945, r=compiler-errors
Add some more regression tests for #67945
Closes #67945, added two tests from https://github.com/rust-lang/rust/issues/67945#issuecomment-572617285, other snippets were already added in #71952 and #77439
r? `@compiler-errors`
Matthias Krüger [Mon, 13 Jun 2022 19:35:56 +0000 (21:35 +0200)]
Rollup merge of #98043 - TaKO8Ki:remove-unnecessary-to-string, r=davidtwco
Remove unnecessary `to_string` and `String::new`
https://github.com/rust-lang/rust/pull/96468/commits/73fa217bc11fbac76f730223f6766c8e03513b5e changed the type of the `suggestion` argument to `impl ToString`. This patch removes unnecessary `to_string` and `String::new`.
Matthias Krüger [Mon, 13 Jun 2022 19:35:55 +0000 (21:35 +0200)]
Rollup merge of #97960 - RalfJung:offset-from, r=oli-obk
interpret: unify offset_from check with offset check
`offset` does the check with a single `check_ptr_access` call while `offset_from` used two calls. Make them both just one one call.
I originally intended to actually factor this into a common function, but I am no longer sure if that makes a lot of sense... the two functions start with pretty different precondition (e.g. `offset` *knows* that the 2nd pointer has the same provenance).
I also reworded the UB messages a little. Saying it "cannot" do something is not how we usually phrase UB (as far as I know). Instead it's not *allowed* to do that.
bors [Sun, 12 Jun 2022 23:25:35 +0000 (23:25 +0000)]
Auto merge of #98020 - TaKO8Ki:use-create-snapshot-for-diagnostic-in-rustc-expand, r=Dylan-DPC
Use `create_snapshot_for_diagnostic` instead of `clone` for `Parser`
Use [`create_snapshot_for_diagnostic`](https://github.com/rust-lang/rust/blob/cd119057160cedea245aa2679add56723f3dc784/compiler/rustc_parse/src/parser/diagnostics.rs#L214-L223) I implemented in https://github.com/rust-lang/rust/pull/94731 instead of `clone` to avoid duplicate unclosed delims errors being emitted when the `Parser` is dropped. I missed this one in #95068.
bors [Sun, 12 Jun 2022 12:41:06 +0000 (12:41 +0000)]
Auto merge of #98025 - Dylan-DPC:rollup-cwt2hb7, r=Dylan-DPC
Rollup of 5 pull requests
Successful merges:
- #97921 (additional docs example for replace **all** of str)
- #97970 (Fix Termination impl panic on closed stderr)
- #97991 (Use safer `strip=symbols`-flag for dylibs on macOS)
- #97992 (Stabilize scoped threads.)
- #98012 (`ValuePairs::PolyTraitRefs` should be called "trait"s in type error diagnostics)
Dylan DPC [Sun, 12 Jun 2022 10:14:28 +0000 (12:14 +0200)]
Rollup merge of #97991 - davidkna:fix-macos-strip, r=joshtriplett
Use safer `strip=symbols`-flag for dylibs on macOS
Closes #93988
To safely strip dylibs on macOS, the `-x` flag is needed per the manpage (see the discussion here: https://github.com/rust-lang/rust/issues/93988#issuecomment-1042574854).
Thus, when the current `crate_type` is producing a dylib (I assume this is the case for proc macros) use the `-x` flag instead of bare `strip` for `strip=symbols`.
bors [Sun, 12 Jun 2022 00:47:54 +0000 (00:47 +0000)]
Auto merge of #97778 - compiler-errors:misc-diagnostics-tidy, r=cjgillot
Tidy up miscellaneous bounds suggestions
Just some small fixes to suggestions
- Generalizes `Ty::is_suggestable` into a `TypeVisitor`, so that it can be called on things other than `Ty`
- Makes `impl Trait` in arg position no longer suggestible (generalizing the fix in #97640)
- Fixes `impl Trait` not being replaced with fresh type param when it's deeply nested in function signature (fixes #97760)
- Fixes some poor handling of `where` clauses with no predicates (also #97760)
- Uses `InferCtxt::resolve_numeric_literals_with_default` so we suggest `i32` instead of `{integer}` (fixes #97677)
Sorry there aren't many tests the fixes. Most of them would just be duplicates of other tests with empty `where` clauses or `impl Trait` in arg position instead of generic params. Let me know if you'd want more test coverage.