David Wood [Wed, 13 Jul 2022 14:02:23 +0000 (15:02 +0100)]
span: add `span_extend_to_line` helper
Adds a simple helper function to the `SourceMap` for extending a `Span`
to encompass the entire line it is on - useful for suggestions where
removing a line is the suggested action.
David Wood [Wed, 13 Jul 2022 12:10:37 +0000 (13:10 +0100)]
middle: add `implies_by` to `#[unstable]`
If part of a feature is stabilized and a new feature is added for the
remaining parts, then the `implied_by` attribute can be used to indicate
which now-stable feature previously contained a item. If the now-stable
feature is still active (if the user has only just updated rustc, for
example) then there will not be an stability error for uses of the item
from the implied feature.
David Wood [Wed, 13 Jul 2022 09:36:12 +0000 (10:36 +0100)]
attr: fix expected meta-item for `#[stable]`
When an unexpected meta item is provided to `#[stable]`, the diagnostic
lists "since" and "note" as expected meta-items, however the surrounding
code actually expects "feature" and "since".
Auto merge of #98843 - Urgau:check-cfg-stage0, r=Mark-Simulacrum
Enable check-cfg in stage0
Now that the bootstrap cargo supports `rustc-check-cfg` we can now enable it with `-Zcheck-cfg=output` and use it in `rustc_llvm` to unblock `--check-cfg` support in stage0.
Auto merge of #99484 - ehuss:update-cargo, r=ehuss
Update cargo
9 commits in 8827baaa781b37872134c1ba692a6f0aeb37890e..d8d30a75376f78bb0fabe3d28ee9d87aa8035309
2022-07-14 02:56:51 +0000 to 2022-07-19 13:59:17 +0000
- docs: fixing minor error in the default timing report filename (rust-lang/cargo#10879)
- Stabilize `--crate-type` flag for `cargo rustc` (rust-lang/cargo#10838)
- Stabilize `-Zmultitarget` (rust-lang/cargo#10766)
- Clean up leftover in unstable documentation (rust-lang/cargo#10874)
- Normalize path for `cargo vendor` output (rust-lang/cargo#10668)
- add a reason to `masquerade_as_nightly_cargo` so it is searchable (rust-lang/cargo#10868)
- Allow '.' in workspace.default-members in non-virtual workspaces. (rust-lang/cargo#10784)
- remove`.masquerade_as_nightly_cargo()` from various tests the no longer need it (rust-lang/cargo#10867)
- remove `.masquerade_as_nightly_cargo()` from build_script_extra_link_arg.rs (rust-lang/cargo#10866)
Auto merge of #98180 - notriddle:notriddle/rustdoc-fn, r=petrochenkov,GuillaumeGomez
Improve the function pointer docs
This is #97842 but for function pointers instead of tuples. The concept is basically the same.
* Reduce duplicate impls; show `fn (T₁, T₂, …, Tₙ)` and include a sentence saying that there exists up to twelve of them.
* Show `Copy` and `Clone`.
* Show auto traits like `Send` and `Sync`, and blanket impls like `Any`.
Michael Howell [Thu, 16 Jun 2022 21:14:38 +0000 (14:14 -0700)]
Improve the function pointer docs
* Reduce duplicate impls; show only the `fn (T)` and include a sentence
saying that there exists up to twelve of them.
* Show `Copy` and `Clone`.
* Show auto traits like `Send` and `Sync`, and blanket impls like `Any`.
Rollup merge of #99457 - SparrowLii:para_iter, r=fee1-dead
use `par_for_each_in` in `par_body_owners` and `collect_crate_mono_items`
Using `par_iter` in non-parallel mode will cause the entire process to abort when any iteration panics. So we can use `par_for_each_in` instead to make the error message consistent with parallel mode. This means that the compiler will output more error messages in some cases. This fixes the following ui tests when set `parallel-compiler = true`:
```
[ui] src/test\ui\privacy\privacy2.rs
[ui] src/test\ui\privacy\privacy3.rs
[ui] src/test\ui\type_length_limit.rs
```
Rollup merge of #99438 - WaffleLapkin:dont_wrap_in_non_zero, r=compiler-errors
Improve suggestions for `NonZeroT` <- `T` coercion error
Currently, when encountering a type mismatch error with `NonZeroT` and `T` (for example `NonZeroU8` and `u8`) we errorneusly suggest wrapping expression in `NonZeroT`:
```text
error[E0308]: mismatched types
--> ./t.rs:7:35
|
7 | let _: std::num::NonZeroU64 = 1;
| -------------------- ^ expected struct `NonZeroU64`, found integer
| |
| expected due to this
|
help: try wrapping the expression in `std::num::NonZeroU64`
|
7 | let _: std::num::NonZeroU64 = std::num::NonZeroU64(1);
| +++++++++++++++++++++ +
```
I've removed this suggestion and added suggestions to call `new` (for `Option<NonZeroT>` <- `T` case) or `new` and `unwrap` (for `NonZeroT` <- `T` case):
```text
error[E0308]: mismatched types
--> ./t.rs:7:35
|
7 | let _: std::num::NonZeroU64 = 1;
| -------------------- ^ expected struct `NonZeroU64`, found integer
| |
| expected due to this
|
help: Consider calling `NonZeroU64::new`
|
7 | let _: std::num::NonZeroU64 = NonZeroU64::new(1).unwrap();
| ++++++++++++++++ ++++++++++
error[E0308]: mismatched types
--> ./t.rs:8:43
|
8 | let _: Option<std::num::NonZeroU64> = 1;
| ---------------------------- ^ expected enum `Option`, found integer
| |
| expected due to this
|
= note: expected enum `Option<NonZeroU64>`
found type `{integer}`
help: Consider calling `NonZeroU64::new`
|
8 | let _: Option<std::num::NonZeroU64> = NonZeroU64::new(1);
| ++++++++++++++++ +
```
https://github.com/rust-lang/rust/issues/99035; the behavior of `$$crate` is potentially unexpected and not ready to be stabilized. https://github.com/rust-lang/rust/pull/99193 attempts to forbid `$$crate` without also destabilizing `$$` more generally.
Rollup merge of #99419 - yoshuawuyts:stabilize-task-ready, r=Mark-Simulacrum
Stabilize `core::task::ready!`
This stabilizes `core::task::ready!` for Rust 1.64. The FCP for stabilization was just completed here https://github.com/rust-lang/rust/issues/70922#issuecomment-1186231855. Thanks!
Rollup merge of #99384 - compiler-errors:issue-99375, r=oli-obk
use body's param-env when checking if type needs drop
The type comes from the body, so we should be using the body's param-env, as opposed to the ADT's param env, because we know less in the latter compared to the former.
I think this should be good to go, there are only two things where I am somewhat unsure:
- Is there a better way to get the fully-qualified path for the suggestion? I tried `self.tcx.def_path_str`, but that didn't seem to always give a correct path for the context.
- Should all this be extracted into it's own method or is it fine where it is?
Rollup merge of #99434 - timvermeulen:skip_next_non_fused, r=scottmcm
Fix `Skip::next` for non-fused inner iterators
`iter.skip(n).next()` will currently call `nth` and `next` in succession on `iter`, without checking whether `nth` exhausts the iterator. Using `?` to propagate a `None` value returned by `nth` avoids this.
Rollup merge of #99335 - Dav1dde:fromstr-docs, r=JohnTitor
Use split_once in FromStr docs
Current implementation:
```rust
fn from_str(s: &str) -> Result<Self, Self::Err> {
let coords: Vec<&str> = s.trim_matches(|p| p == '(' || p == ')' )
.split(',')
.collect();
let x_fromstr = coords[0].parse::<i32>()?;
let y_fromstr = coords[1].parse::<i32>()?;
Ok(Point { x: x_fromstr, y: y_fromstr })
}
```
Creating the vector is not necessary, `split_once` does the job better.
Alternatively we could also remove `trim_matches` with `strip_prefix` and `strip_suffix`:
```rust
let (x, y) = s
.strip_prefix('(')
.and_then(|s| s.strip_suffix(')'))
.and_then(|s| s.split_once(','))
.unwrap();
```
The question is how much 'correctness' is too much and distracts from the example. In a real implementation you would also not unwrap (or originally access the vector without bounds checks), but implementing a custom Error and adding a `From<ParseIntError>` and implementing the `Error` trait adds a lot of code to the example which is not relevant to the `FromStr` trait.
Rollup merge of #97183 - oli-obk:tait_ice_async, r=jackh726
wf-check generators
fixes #90409
We should not rely on generators being well formed by construction now that they can get used via type alias impl trait (and thus users can choose generic arguments that are invalid). This can cause surprising behaviour if (definitely unsound) transmutes are used, and it's generally saner to just check for well formedness.
Auto merge of #98189 - mystor:fast_ident_literal, r=eddyb
proc_macro/bridge: stop using a remote object handle for proc_macro Ident and Literal
This is the fourth part of https://github.com/rust-lang/rust/pull/86822, split off as requested in https://github.com/rust-lang/rust/pull/86822#pullrequestreview-1008655452. This patch transforms the `Ident` and `Group` types into structs serialized over IPC rather than handles.
Symbol values are interned on both the client and server when deserializing, to avoid unnecessary string copies and keep the size of `TokenTree` down. To do the interning efficiently on the client, the proc-macro crate is given a vendored version of the fxhash hasher, as `SipHash` appeared to cause performance issues. This was done rather than depending on `rustc_hash` as it is unfortunately difficult to depend on crates from within `proc_macro` due to it being built at the same time as `std`.
In addition, a custom arena allocator and symbol store was also added, inspired by those in `rustc_arena` and `rustc_span`. To prevent symbol re-use across multiple invocations of a macro on the same thread, a new range of `Symbol` names are used for each invocation of the macro, and symbols from previous invocations are cleaned-up.
In order to keep `Ident` creation efficient, a special ASCII-only case was added to perform ident validation without using RPC for simple identifiers. Full identifier validation couldn't be easily added, as it would require depending on the `rustc_lexer` and `unicode-normalization` crates from within `proc_macro`. Unicode identifiers are validated and normalized using RPC.
See the individual commit messages for more details on trade-offs and design decisions behind these patches.
- Use `expr.hir_id.owner` instead of `self.tcx.parent_module(expr.hir_id)`
- Use `.type_at()` instead of `.first()` + `.expect_ty()`
- Use single `.find()` with `&&` condition
Auto merge of #99422 - Dylan-DPC:rollup-htjofm6, r=Dylan-DPC
Rollup of 7 pull requests
Successful merges:
- #98839 (Add assertion that `transmute_copy`'s U is not larger than T)
- #98998 (Remove branch target prologues from `#[naked] fn`)
- #99198 (add missing null ptr check in alloc example)
- #99344 (rustdoc: avoid inlining items with duplicate `(type, name)`)
- #99351 (Use `typeck_results` to get accurate qpath res for arg mismatch error)
- #99378 (interpret/visitor: add missing early return)
- #99394 (Add regression test for #95230)
proc_macro: Move subspan to be a method on Span in the bridge
This method is still only used for Literal::subspan, however the
implementation only depends on the Span component, so it is simpler and
more efficient for now to pass down only the information that is needed.
In the future, if more information about the Literal is required in the
implementation (e.g. to validate that spans line up as expected with
source text), that extra information can be added back with extra
arguments.
proc_macro: stop using a remote object handle for Literal
This builds on the symbol infrastructure built for `Ident` to replicate
the `LitKind` and `Lit` structures in rustc within the `proc_macro`
client, allowing literals to be fully created and interacted with from
the client thread. Only parsing and subspan operations still require
sync RPC.
proc_macro: stop using a remote object handle for Ident
Doing this for all unicode identifiers would require a dependency on
`unicode-normalization` and `rustc_lexer`, which is currently not
possible for `proc_macro` due to it being built concurrently with `std`
and `core`. Instead, ASCII identifiers are validated locally, and an RPC
message is used to validate unicode identifiers when needed.
String values are interned on the both the server and client when
deserializing, to avoid unnecessary copies and keep Ident cheap to copy and
move. This appears to be important for performance.
The client-side interner is based roughly on the one from rustc_span, and uses
an arena inspired by rustc_arena.
RPC messages passing symbols always include the full value. This could
potentially be optimized in the future if it is revealed to be a
performance bottleneck.
Despite now having a relevant implementaion of Display for Ident, ToString is
still specialized, as it is a hot-path for this object.
The symbol infrastructure will also be used for literals in the next
part.
proc_macro: use fxhash within the proc_macro crate
Unfortunately, as it is difficult to depend on crates from within proc_macro,
this is done by vendoring a copy of the hasher as a module rather than
depending on the rustc_hash crate.
This probably doesn't have a substantial impact up-front, however will be more
relevant once symbols are interned within the proc_macro client.
Rollup merge of #98998 - workingjubilee:naked-means-no-clothes-enforcement-technology, r=Amanieu
Remove branch target prologues from `#[naked] fn`
This patch hacks around rust-lang/rust#98768 for now via injecting appropriate attributes into the LLVMIR we emit for naked functions. I intend to pursue this upstream so that these attributes can be removed in general, but it's slow going wading through C++ for me.
Rollup merge of #98839 - 5225225:assert_transmute_copy_size, r=thomcc
Add assertion that `transmute_copy`'s U is not larger than T
This is called out as a safety requirement in the docs, but because knowing this can be done at compile time and constant folded (just like the `align_of` branch is removed), we can just panic here.
I've looked at the asm (using `cargo-asm`) of a function that both is correct and incorrect, and the panic is completely removed, or is unconditional, without needing build-std.
I don't expect this to cause much breakage in the wild. I scanned through https://miri.saethlin.dev/ub for issues that would look like this (error: Undefined Behavior: memory access failed: alloc1768 has size 1, so pointer to 8 bytes starting at offset 0 is out-of-bounds), but couldn't find any.
That doesn't rule out it happening in crates tested that fail earlier for some other reason, though, but it indicates that doing this is rare, if it happens at all. A crater run for this would need to be build and test, since this is a runtime thing.
Auto merge of #99232 - lcnr:no-bound-vars-check, r=jackh726
`replace_bound_vars` fast path: check predicates, don't check consts
split out from #98900
`ty::Const` doesn't have precomputed type flags, so
computing `has_vars_bound_at_or_above` for constants
requires us to visit the const and its contained types
and constants. A noop fold should be pretty much equally as
fast so removing it prevents us from walking the constant twice
in case it contains bound vars.
Turns out that all we need to do here is reorder the bounds checks to convince LLVM that all the bounds checks can be removed. It seems like LLVM just fails to propagate the original length information past the first bounds check and into the second one. With this implementation it doesn't need to, each check can be proven inbounds based on the one immediately previous.
I've gradually convinced myself that this implementation is unambiguously better based on the above logic, but maybe this is still deserving of a codegen test?
Also the mentioned borrowck limitation no longer seems to exist.
Auto merge of #99181 - lcnr:arenaGTrc, r=wesleywiser
`arena > Rc` for query results
The `Rc`s have to live for the whole duration as their count cannot go below 1 while stored as part of the query results.
By storing them in an arena we should save a bit of memory because we don't have as many independent allocations and also don't have to clone the `Rc` anymore.
Auto merge of #99391 - JohnTitor:rollup-tdigzzo, r=JohnTitor
Rollup of 6 pull requests
Successful merges:
- #98383 (Remove restrictions on compare-exchange memory ordering.)
- #99350 (Be more precise when suggesting removal of parens on unit ctor)
- #99356 (Do not constraint TAITs when checking impl/trait item compatibility)
- #99360 (Do not ICE when we have `-Zunpretty=expanded` with invalid ABI)
- #99373 (Fix source code sidebar tree auto-expand)
- #99374 (Fix doc for `rchunks_exact`)
Rollup merge of #99356 - compiler-errors:tait-in-assoc-ty-supertraits, r=oli-obk
Do not constraint TAITs when checking impl/trait item compatibility
Check out the UI test for the example.
Open to other approaches to fix this issue -- ideally we _would_ be able to collect this opaque type constraint in a way to use it in `find_opaque_ty_constraints`, so we can report a better mismatch error in the incompatible case, and just allow it in the compatible case. But that seems like a bigger refactor, so I wouldn't want to start it unless someone else thought it was a good idea.
Rollup merge of #99350 - compiler-errors:issue-99240, r=fee1-dead
Be more precise when suggesting removal of parens on unit ctor
* Fixes #99240 by only suggesting to remove parens on path exprs, not arbitrary expressions with enum type
* Generalizes by suggesting removal of parens on unit struct, too, because why not?
Rollup merge of #98383 - m-ou-se:remove-memory-order-restrictions, r=joshtriplett
Remove restrictions on compare-exchange memory ordering.
We currently don't allow the failure memory ordering of compare-exchange operations to be stronger than the success ordering, as was the case in C++11 when its memory model was copied to Rust. However, this restriction was lifted in C++17 as part of [p0418r2](https://wg21.link/p0418r2). It's time we lift the restriction too.
Use ICF (identical code folding) for building rustc
It seems that ICF (identical code folding) is able to remove duplicated functions created by monomorphization from binaries, resulting in smaller binary size and better i-cache utilization. Let's see if it helps for `rustc`.
I'm not sure if `lld` is even used for linking `rustc` on the Linux `dist` builder, let's see.
Auto merge of #99033 - 5225225:interpreter-validity-checks, r=oli-obk
Use constant eval to do strict mem::uninit/zeroed validity checks
I'm not sure about the code organisation here, I just dumped the check in rustc_const_eval at the root. Not hard to move it elsewhere, in any case.
Also, this means cranelift codegen intrinsics lose the strict checks, since they don't seem to depend on rustc_const_eval, and I didn't see a point in keeping around two copies.
I also left comments in the is_zero_valid methods about "uhhh help how do i do this", those apply to both methods equally.
Also rustc_codegen_ssa now depends on rustc_const_eval... is this okay?
Pinging `@RalfJung` since you were the one who mentioned this to me, so I'm assuming you're interested.
Haven't had a chance to run full tests on this since it's really warm, and it's 1AM, I'll check out any failures/comments in the morning :)