there are two case that doesn't not match the original macro pattern at [here](https://github.com/rust-lang/rust/blob/master/src/librustc_lint/unused.rs#L146) and [here](https://github.com/rust-lang/rust/blob/master/src/libsyntax/parse/diagnostics.rs#L539) as the provided param is already a bool or the check condition is not `x != 1`, so I change the macro accept a boolean expr instead of number to fit all the cases.
Rollup merge of #64136 - crgl:doc-from-parser-lhs, r=Centril
Document From trait for LhsExpr in parser
Add doc for From trait for converting P<Expr> and Option<ThinVec<Attribute>> to LhsExpr
As part of issue rust-lang#51430 (cc @skade).
Both of these should just be moving an address and setting a discriminant in an enum. The main thing I'm not sure about is whether it's worth documenting the branch in the From<Option<ThinVec<Attribute>>. As far as I can tell it doesn't seem like it is optimized away (although if the discriminant happened to work out you could just copy the pointer and the discriminant which might be cheaper, but that's not guaranteed). So it seems like if it's being called often, it's doubling the number of possible branch mispredictions on this Option, which could be a significant cost.
Let me know if there's anything that needs fixing and I'll get to it as soon as possible!
* Documentation comments like `/// Doc` on parameters.
* Code expansion of a user-defined `#[proc_macro_attribute]` macro used on parameters.
* Built-in attributes other than `cfg`, `cfg_attr`, `allow`, `warn`, `deny`, and `forbid`. Currently, only the lints `unused_variables` and `unused_mut` have effect and may be controlled on parameters.
## Motivation
The chief motivations for stabilizing `param_attrs` include:
* Finer conditional compilation with `#[cfg(..)]` and linting control of variables.
* Richer macro DSLs created by users.
* External tools and compiler internals can take advantage of the additional information that the parameters provide.
For more examples, see the [RFC][rfc motivation].
## Reference guide
In the grammar of function and function pointer, the grammar of variadic tails (`...`) and parameters are changed respectively from:
More generally, where there's a list of formal (value) parameters separated or terminated by `,` and delimited by `(` and `)`. Each parameter in that list may optionally be prefixed by `OuterAttr+`.
Note that in all cases, `OuterAttr*` applies to the whole parameter and not just the pattern. This distinction matters in pretty printing and in turn for macros.
## History
* On 2018-10-15, @Robbepop proposes [RFC 2565][rfc], "Attributes in formal function parameter position".
* On 2019-04-30, [RFC 2565][rfc] is merged and the tracking issue is made.
* On 2019-06-12, a partial implementation was completed. The implementation was done in [#60669][60669] by @c410-f3r and the PR was reviewed by @petrochenkov and @Centril.
* On 2019-07-29, [#61238][61238] was fixed in [#61856][61856]. The issue fixed was that lint attributes on function args had no effect. The PR was written by @c410-f3r and reviewed by @matthewjasper, @petrochenkov, and @oli-obk.
* On 2019-08-02, a bug [#63210][63210] was filed wherein the attributes on formal parameters would not be passed to macros. The issue was about forgetting to call the relevant method in `fn print_arg` in the pretty printer. In [#63212][63212], written by @Centril on 2019-08-02 and reviewed by @davidtwco, the issue aforementioned was fixed.
* This PR stabilizes `param_attrs`.
## Tests
* [On Rust 2018, attributes aren't permitted on function parameters without a pattern in trait definitions.](https://github.com/rust-lang/rust/blob/master/src/test/ui/rfc-2565-param-attrs/param-attrs-2018.rs)
* [All attributes that should be allowed. This includes `cfg`, `cfg_attr`, and lints check attributes.](https://github.com/rust-lang/rust/blob/master/src/test/ui/rfc-2565-param-attrs/param-attrs-allowed.rs)
* [Built-in attributes, which should be forbidden, e.g., `#[test]`, are.](https://github.com/rust-lang/rust/blob/master/src/test/ui/rfc-2565-param-attrs/param-attrs-builtin-attrs.rs)
* [`cfg` and `cfg_attr` are properly evaluated.](https://github.com/rust-lang/rust/blob/master/src/test/ui/rfc-2565-param-attrs/param-attrs-cfg.rs)
* [`unused_mut`](https://github.com/rust-lang/rust/blob/46f405ec4d7c6bf16fc2eaafe7541019f1da2996/src/test/ui/rfc-2565-param-attrs/param-attrs-cfg.rs) and [`unused_variables`](https://github.com/rust-lang/rust/blob/master/src/test/ui/lint/lint-unused-variables.rs) are correctly applied to parameter patterns.
* [Pretty printing takes formal parameter attributes into account.](https://github.com/rust-lang/rust/blob/master/src/test/ui/rfc-2565-param-attrs/param-attrs-pretty.rs)
## Possible future work
* Custom attributes inside function parameters aren't currently supported but it is something being worked on internally.
* Since documentation comments are syntactic sugar for `#[doc(...)]`, it is possible to allow literal `/// Foo` comments on function parameters.
`min_by` and `max_by` are somewhat trivial to implement, but not entirely because `min_by` returns the first value in case the two are equal (and `max_by` the second). `min` and `max` can be implemented in terms of `min_by` and `max_by`, but not as easily the other way around.
To give an example of why I think these functions could be useful: the `Iterator::{min_by, min_by_key, max_by, max_by_key}` methods all currently hard-code the behavior mentioned above which is an ever so small duplication of logic. If we delegate them to `cmp::{min_by, max_by}` methods instead, we get the correct behavior for free. (edit: this is now included in the PR)
I added `min_by_key` / `max_by_key` for consistency's sake but I wouldn't mind removing them. I don't have a particular use case in mind for them, and `min_by` / `max_by` seem to be more useful.
Auto merge of #64584 - nikomatsakis:issue-64477-generator-capture-types, r=eddyb
record fewer adjustment types in generator witnesses, avoid spurious drops in MIR construction
Don't record all intermediate adjustment types -- That's way more than is needed, and winds up recording types that will never appear in MIR.
Note: I'm like 90% sure that this logic is correct, but this stuff is subtle and can be hard to keep straight. However, the risk of this PR is fairly low -- if we miss types here, I believe the most common outcome is an ICE.
This fixes the original issue cited by #64477, but I'm leaving the issue open for now since there may be other cases we can detect and improve in a targeted way.
Auto merge of #64553 - alexcrichton:windows-bash-install-scripts, r=Mark-Simulacrum
azure: Convert Windows installations scripts to `bash`
Looks like `script`, which uses `cmd.exe`, doesn't have fail-fast
behavior and if a leading command fails the script doesn't actually fail
so long as the last command succeeds. We instead want the opposite
behavior where if any step fails the whole script fails.
I don't really know `cmd.exe` that well, nor powershell, so I've opted
to move everything to `bash` which should be a good common denominator
amongst all platforms to work with. Additionally I know that `set -e`
works to cause scripts to fail fast.
Auto merge of #64576 - pietroalbini:split-aws-tokens, r=alexcrichton
ci: split aws credentials in two separate users with scoped perms
This commit changes our CI to use two separate IAM users to authenticate with AWS:
* `ci--rust-lang--rust--sccache`: has access to the `rust-lang-ci-sccache2` S3 bucket and its credentials are available during the whole build.
* `ci--rust-lang--rust--upload`: has access to the `rust-lang-ci2` S3 bucket and its credentials are available just during the upload step.
The new tokens are available in the `prod-credentials` library.
Rollup merge of #64613 - alexcrichton:less-doc-copies, r=Mark-Simulacrum
rustbuild: Copy crate doc files fewer times
Previously when building documentation for the standard library we'd
copy all the files 5 times, and these files include libcore/libstd docs
which are huge! This commit instead only copies the files after rustdoc
has been run for each crate, reducing the number of redundant copies
we're making.
Rollup merge of #64611 - alexcrichton:no-libstd-twice, r=Mark-Simulacrum
rustbuild: Don't package libstd twice
Looks like the packaging step for the standard library was happening
twice on CI, but it only needs to happen once! The `Analysis` packaging
step accidentally packaged `Std` instead of relying on compiling `Std`,
which meant that we ended up packaging it twice erroneously.
Rollup merge of #64592 - Aaron1011:feature/unreachable-span, r=Centril
Point at original span when emitting unreachable lint
Fixes #64590
When we emit an 'unreachable' lint, we now add a note pointing at the
expression that actually causes the code to be unreachable (e.g.
`return`, `break`, `panic`).
This is especially useful when macros are involved, since a diverging
expression might be hidden inside of a macro invocation.
Niko Matsakis [Thu, 19 Sep 2019 15:41:10 +0000 (11:41 -0400)]
avoid generating drops for moved operands of calls
Currently, after a CALL terminator is created in MIR, we insert DROP
statements for all of its operands -- even though they were just moved
shortly before! These spurious drops are later removed, but not before
causing borrow check errors.
This PR series modifies the drop code to track operands that were
moved and avoid creating drops for them.
Right now, I'm only using this mechanism for calls, but it seems
likely it could be used in more places.
Alex Crichton [Thu, 19 Sep 2019 14:48:04 +0000 (07:48 -0700)]
rustbuild: Copy crate doc files fewer times
Previously when building documentation for the standard library we'd
copy all the files 5 times, and these files include libcore/libstd docs
which are huge! This commit instead only copies the files after rustdoc
has been run for each crate, reducing the number of redundant copies
we're making.
Alex Crichton [Thu, 19 Sep 2019 14:46:24 +0000 (07:46 -0700)]
rustbuild: Don't package libstd twice
Looks like the packaging step for the standard library was happening
twice on CI, but it only needs to happen once! The `Analysis` packaging
step accidentally packaged `Std` instead of relying on compiling `Std`,
which meant that we ended up packaging it twice erroneously.
Alex Crichton [Tue, 17 Sep 2019 14:40:27 +0000 (07:40 -0700)]
azure: Convert Windows installations scripts to `bash`
Looks like `script`, which uses `cmd.exe`, doesn't have fail-fast
behavior and if a leading command fails the script doesn't actually fail
so long as the last command succeeds. We instead want the opposite
behavior where if any step fails the whole script fails.
I don't really know `cmd.exe` that well, nor powershell, so I've opted
to move everything to `bash` which should be a good common denominator
amongst all platforms to work with. Additionally I know that `set -e`
works to cause scripts to fail fast.
Note that some scripts remain as `script` since they don't appear to
work in` bash`. I'm not really sure why but I reorganized them slightly
to have the "meaty command" run at the end.
Pietro Albini [Wed, 18 Sep 2019 09:10:46 +0000 (11:10 +0200)]
ci: split aws credentials in two separate users with scoped perms
This commit changes our CI to use two separate IAM users to
authenticate with AWS:
* ci--rust-lang--rust--sccache: has access to the rust-lang-ci-sccache2
S3 bucket and its credentials are available during the whole build.
* ci--rust-lang--rust--upload: has access to the rust-lang-ci2 S3 bucket
and its credentials are available just during the upload step.
The new tokens are available in the `prod-credentials` library.
Auto merge of #64598 - Centril:rollup-htmf39p, r=Centril
Rollup of 5 pull requests
Successful merges:
- #63630 (Update installed compiler dependencies)
- #64536 (Update Cargo)
- #64554 (Polonius: more `ui` test suite fixes)
- #64566 (A more generic interface for dataflow analysis)
- #64591 (Fix a minor grammar nit, update UI tests)
Rollup merge of #64566 - ecstatic-morse:generic-dataflow, r=oli-obk
A more generic interface for dataflow analysis
#64470 requires a transfer function that is slightly more complex than the typical `gen`/`kill` one. Namely, it must copy state bits between locals when assignments occur (see #62547 for an attempt to make this fit into the existing framework). This PR contains a dataflow interface that allows for arbitrary transfer functions. The trade-off is efficiency: we can no longer coalesce transfer functions for blocks and must visit each statement individually while iterating to fixpoint.
Another issue is that poorly behaved transfer functions can result in an analysis that fails to converge. `gen`/`kill` sets do not have this problem. I believe that, in order to guarantee convergence, flipping a bit from `false` to `true` in the entry set cannot cause an output bit to go from `true` to `false` (negate all preceding booleans when `true` is the bottom value). Perhaps someone with a more formal background can confirm and we can add a section to the docs?
This approach is not maximally generic: it still requires that the lattice used for analysis is the powerset of values of `Analysis::Idx` for the `mir::Body` of interest. This can be done at a later date. Also, this is the bare minimum to get #64470 working. I've not adapted the existing debug framework to work with the new analysis, so there are no `rustc_peek` tests either. I'm planning to do this after #64470 is merged.
Finally, my ultimate plan is to make the existing, `gen`/`kill`-based `BitDenotation` a special case of `generic::Analysis`. Currently they share a ton of code. I should be able to do this without changing any implementers of `BitDenotation`. Something like:
Rollup merge of #64554 - lqd:polonius_tests4, r=nikomatsakis
Polonius: more `ui` test suite fixes
Since #62736, new tests have been added, and the `run-pass` suite was merged into the `ui` suite.
This PR adds the missing tests expectations for Polonius, and updates the existing ones where the NLL output has changed in some manner (e.g. ordering of notes)
Those are the trivial cases, but a more-detailed explanation is available [in this write-up](https://hackmd.io/CjYB0fs4Q9CweyeTdKWyEg?both#26-async-awaitasync-borrowck-escaping-closure-errorrs-outputs-from-NLL-Polonius-diff) starting at test case 26: they are only differing in diagnostics and instances of other existing test cases differences.
Only 3 of the 9020 tests are still "failing" at the moment (1 failure, 2 OOMs).
Aaron Hill [Wed, 18 Sep 2019 22:22:13 +0000 (18:22 -0400)]
Point at original span when emitting unreachable lint
Fixes #64590
When we emit an 'unreachable' lint, we now add a note pointing at the
expression that actually causes the code to be unreachable (e.g.
`return`, `break`, `panic`).
This is especially useful when macros are involved, since a diverging
expression might be hidden inside of a macro invocation.
The super-hot call site of `inlined_shallow_resolve()` basically does
`r.inlined_shallow_resolve(ty) != ty`. This commit introduces a
version of that function specialized for that particular call pattern,
`shallow_resolve_changed()`. Incredibly, this reduces the instruction
count for `keccak` by 5%.
The commit also renames `inlined_shallow_resolve()` as
`shallow_resolve()` and removes the `inline(always)` annotation, as it's
no longer nearly so hot.
Rollup merge of #64580 - ehuss:update-books, r=ehuss
Update books
## book
24 commits in 7ddc46460f09a5cd9bd2a620565bdc20b3315ea9..871416b85c1a73717d65d6f4a9ea29e5aef3db0e
2019-06-27 09:50:36 -0400 to 2019-09-16 09:46:20 -0400
- Ch16-2 add missing Ferris (rust-lang/book#2033)
- Update version mentioned on the front page
- Update error messages (rust-lang/book#1737)
- Update version of Rust used to 1.37
- Replace Cargo docs link with a more specific link (rust-lang/book#2066)
- Added missing await reserved keyword (rust-lang/book#2064)
- add does_not_compile for a snippet (rust-lang/book#2056)
- Added second missing dyn (rust-lang/book#2046)
- Removed unnecessary & in function call (rust-lang/book#2038)
- Printing non-Display structs is a *compile* error (rust-lang/book#2031)
- Update Readme mdBook version to match linked file (rust-lang/book#2012)
- Update loose mdbook version reference (rust-lang/book#2003)
- Added a bullet point to have list of things unsafe allows for match u… (rust-lang/book#1993)
- Rewrote a confusing sentence (rust-lang/book#1986)
- Replace deprecated `...` range syntax with `..=` (rust-lang/book#1977)
- correct wording for integration test doc (rust-lang/book#1971)
- Mark the dangle function as does_not_compile (rust-lang/book#1965)
- Add more words to the quote from the actual Go documentation (rust-lang/book#1960)
- Remove unused import in lfp (rust-lang/book#1944)
- A small typo? (rust-lang/book#1931)
- Make the code not compile to match the text (rust-lang/book#1926)
- Ferris does-not-compile added (ch9.2) (rust-lang/book#1925)
- ch07 - remove note regarding use and relative path (rust-lang/book#1820)
- tweak opening paragraph of deref coercions (rust-lang/book#1749)
## rust-by-example
9 commits in e76be6b2dc84c6a992e186157efe29d625e29b94..67cfbf31df880728dcf7cb35b15b028ec92caf31
2019-09-03 07:42:26 -0300 to 2019-09-18 09:36:40 -0300
- Fix rust-lang/rust-by-example#90: Add supertraits and Fully Qualified syntax (rust-lang/rust-by-example#1259)
- Fix some broken links. (rust-lang/rust-by-example#1258)
- Fix rust-lang/rust-by-example#1253: Document enum type aliases (rust-lang/rust-by-example#1255)
- Inline code in some new/changed chapters (rust-lang/rust-by-example#1254)
- fix rust-lang/rust-by-example#1067: explain that unit tests can return Result<()> (rust-lang/rust-by-example#1252)
- Fix rust-lang/rust-by-example#1060: add page on Impl Trait (rust-lang/rust-by-example#1251)
- Fix rust-lang/rust-by-example#1053: Added a page about the dyn keyword (rust-lang/rust-by-example#1249)
- Fix rust-lang/rust-by-example#1110: add examples of ? and Option (rust-lang/rust-by-example#1250)
- fix 1037: add the TryFrom chapter back in (rust-lang/rust-by-example#1247)
Rollup merge of #64532 - ecstatic-morse:dataflow-cursor-get, r=tmandry
Replace `state_for_location` with `DataflowResultsCursor`
These are two different ways of getting the same data from the result of a dataflow analysis. However, `state_for_location` goes quadratic if you try to call it for every statement in the body.
Rollup merge of #64348 - arnohaase:pr_documentation_spin_loop_hint, r=alexcrichton
PR: documentation spin loop hint
The documentation for 'spin loop hint' explains that yield is better if the lock holder is running on the same CPU. I suggest that 'CPU or core' would be clearer.
Rollup merge of #64207 - sinkuu:pub_dataflow, r=tmandry
Make rustc_mir::dataflow module pub (for clippy)
I'm working on fixing false-positives of a MIR-based clippy lint (https://github.com/rust-lang/rust-clippy/pull/4509), and in need of the dataflow infrastructure.
Auto merge of #64570 - tmandry:rollup-3pg02lj, r=tmandry
Rollup of 4 pull requests
Successful merges:
- #64486 (Print out more information for `-Zunpretty=expanded,hygiene`)
- #64503 (rename Allocation::retag -> with_tags_and_extra)
- #64516 (update Nomicon and Reference)
- #64528 (Load proc macro metadata in the correct order.)
Rollup merge of #64528 - Aaron1011:fix/proc-macro-type, r=alexcrichton
Load proc macro metadata in the correct order.
Serialized proc macro metadata is assumed to have a one-to-one
correspondence with the entries in static array generated by proc_macro_harness.
However, we were previously serializing proc macro metadata in a
different order than proc macros were laied out in the static array.
This lead to us associating the wrong data with a proc macro when
generating documentation, causing Rustdoc to generate incorrect docs for
proc macros.
This commit keeps track of the order in which we insert proc macros into
the generated static array. We use this same order when serializing proc
macro metadata, ensuring that we can later associate the metadata for a
proc macro with its entry in the static array.
Rollup merge of #64503 - RalfJung:miri-retag, r=oli-obk
rename Allocation::retag -> with_tags_and_extra
This is more consistent with `Pointer::with_tag`. Also, "retag" is a [term from Stacked Borrows](https://github.com/rust-lang/unsafe-code-guidelines/blob/master/wip/stacked-borrows.md#retagging) with a [corresponding Machine hook](https://doc.rust-lang.org/nightly/nightly-rustc/rustc_mir/interpret/machine/trait.Machine.html#method.retag), and this function has nothing to do with that other use of the term.
Rollup merge of #64544 - RalfJung:build-manifest, r=pietroalbini
build-manifest: re-add some comments
https://github.com/rust-lang/rust/pull/64543 also reverted the comments I added. This adds them back.
Includes https://github.com/rust-lang/rust/pull/64543.
Rollup merge of #64502 - RalfJung:miri-toolstate, r=pietroalbini
avoid duplicate issues for Miri build failures
Currently, when Miri regressed from test-pass to test-fail, we pen an issue -- and then when it regresses further from test-fail to build-fail, we open a *second* issue.
This changes the logic to avoid the redundant second issue for Miri.
Rollup merge of #64394 - nnethercote:shrink-SubregionOrigin, r=Mark-Simulacrum
Shrink `SubregionOrigin`.
It's currently 120 bytes on x86-64, due to one oversized variant
(`Subtype`). This commit boxes `Subtype`'s contents, reducing the size
of `SubregionOrigin` to 32 bytes.
The change speeds things up by avoiding lots of `memcpy` calls, mostly
relating to `RegionConstraintData::constraints`, which is a `BTreeMap`
with `SubregionOrigin` values.
Auto merge of #64525 - nikomatsakis:issue-64512-drop-order-tail-temp, r=davidtwco
adjust desugaring for async fn to correct drop order
Old desugaring, given a user function body `{ $stmts; $expr }`
```
{
let $param_pattern0 = $raw_param0;
...
let $param_patternN = $raw_paramN;
$stmts;
$expr
}
```
New desugaring:
```
{
let $param_pattern0 = $raw_param0;
...
let $param_patternN = $raw_paramN;
drop-temps {
$stmts;
$expr
}
}
```
The drop-temps is an internal bit of HIR that drops temporaries from the resulting expression, but it should be equivalent to `return { $stmts; $expr }`.