Rollup merge of #87832 - wesleywiser:fix_match_step, r=davidtwco
Fix debugger stepping behavior with `match` expressions
Previously, we would set up the source lines for `match` expressions so
that the code generated to perform the test of the scrutinee was matched
to the line of the arm that required the test and then jump from the arm
block to the "next" block was matched to all of the lines in the `match`
expression.
While that makes sense, it has the side effect of causing strange
stepping behavior in debuggers.
I've changed the source information so that all of the generated tests
are sourced to `match {scrutinee}` and the jumps are sourced to the last
line of the block they are inside. This resolves the weird stepping
behavior in all debuggers and resolves some instances of "ambiguous
symbol" errors in WinDbg preventing the user from setting breakpoints at
`match` expressions.
Joshua Nelson [Sat, 21 Aug 2021 20:14:56 +0000 (20:14 +0000)]
Fix the bugs and add a regression test
- All attributes for an item need to be considered at once, they can't
be considered a line at a time.
- The top-level crate was not being visited. This bug was caught by
`extern-crate-used-only-in-link`, which I'm very glad I added.
- Make the loader private to the module, so that only one function is
exposed.
bors [Thu, 26 Aug 2021 15:24:01 +0000 (15:24 +0000)]
Auto merge of #88308 - eddyb:cooked-layouts, r=nagisa
Morph `layout_raw` query into `layout_of`.
Before this PR, `LayoutCx::layout_of` wrapped the `layout_raw` query, to:
* normalize the type, before attempting to compute the layout
* pass the layout to `record_layout_for_printing`, for `-Zprint-type-sizes`
Moving those two responsibilities into the query may reduce overhead (due to cached calls skipping those steps), but I want to do a perf run to know.
One of the changes I had to make was changing the return type of the query, to be able to both get out the type produced by normalizing inside the query *and* to match the signature of the old `TyCtxt::layout_of`. This change may be worse, perf-wise, so that's another reason I want to check.
.L__unnamed_1:
.asciz "\376\312\357\276\255\336\000"
.zero 16
.size .L__unnamed_1, 24
```
which copies a bunch of zeros in place of the undef bytes, the same as before this change.
Edit: generating partially-undef constants isn't viable at the moment anyways due to #84565, so it's disabled
bors [Thu, 26 Aug 2021 01:14:16 +0000 (01:14 +0000)]
Auto merge of #88069 - Mark-Simulacrum:llvm-pgo, r=pietroalbini
PGO for LLVM builds on x86_64-unknown-linux-gnu in CI
This shows up to 6% less instruction counts with larger - up to 18% - wins on cycles
on multiple benchmarks, and up to 19% wins on the -j1 wall times for rustc self-compilation.
We can afford to spend the extra cycles building LLVM essentially once more for
the x86_64-unknown-linux-gnu CI build today. The builder finishes in around 50
minutes on average, and this adds just 10 more minutes. Given the sizeable
improvements in compiler performance, this is definitely worth it.
Noah Lev [Wed, 25 Aug 2021 21:40:06 +0000 (14:40 -0700)]
Adjust spans
* Highlight the whole pattern if it has no fields
* Highlight the whole definition if it has no fields
* Only highlight the pattern name if the pattern is multi-line
* Determine whether a pattern is multi-line based on distance from name
to last field, rather than first field
Mark Rousskov [Tue, 24 Aug 2021 21:15:14 +0000 (17:15 -0400)]
Bump sccache used in CI to v0.2.15
This skips bumping Windows sccache because we run into compilation failures when
doing so (-m32 not supported by clang-cl?). Not clear on cause, but seems
easiest to just hold back.
This should avoid PGO-related failures encountered on Linux, and more broadly
seems like a good idea on other platforms as well (though it is likely not
necessary right this moment).
Fix debugger stepping behavior around `match` expressions
Previously, we would set up the source lines for `match` expressions so
that the code generated to perform the test of the scrutinee was matched
to the line of the arm that required the test and then jump from the arm
block to the "next" block was matched to all of the lines in the `match`
expression.
While that makes sense, it has the side effect of causing strange
stepping behavior in debuggers.
I've changed the source information so that all of the generated tests
are sourced to `match {scrutinee}` and the jumps are sourced to the last
line of the block they are inside. This resolves the weird stepping
behavior in all debuggers and resolves some instances of "ambiguous
symbol" errors in WinDbg preventing the user from setting breakpoints at
`match` expressions.
Rollup merge of #88299 - ijackson:bufwriter, r=Mark-Simulacrum
Stabilise BufWriter::into_parts
The FCP for this has already completed, in #80690.
This was just blocked on #85901 (which changed the name), which is now merged. The original stabilisation MR was #84770 but that has a lot of noise in it, and I also accidentally deleted the branch while trying to tidy up. So here is a new MR. Sorry for the noise.
Rollup merge of #88298 - ijackson:errorkind-reorder, r=dtolnay
Errorkind reorder
I was doing a bit more work in this area and the untidiness of these two orderings bothered me.
The commit messages have the detailed rationale. For your convenience, I c&p them here:
```
io::ErrorKind: rationalise ordering in main enum
It is useful to keep some coherent structure to this ordering. In
particular, Other and Uncategorized should be next to each other, at
the end.
Also it seems to make sense to treat UnexpectedEof and OutOfMemory
specially, since they are not like the other errors (despite
OutOfMemory also being generatable by some OS errors).
So:
* Move Other to the end, just before Uncategorized
* Move Unsupported to between Interrupted and UnexpectedEof
* Add some comments documenting where to add things
```
```
io::Error: alphabeticise the match in as_str()
There was no rationale for the previous ordering.
```
r? kennytm since that's who rust-highfive picked before, in #88294 which I accidentally closed.
7 commits in 7e49659102f0977d9142190e1ba23345c0f00eb1..687e21bde2ea10c261f79fa14797c5137425098d
2021-08-03 21:41:35 -0400 to 2021-08-18 20:48:38 -0400
- Small tweaks to Ferris size and position
- Retain previous height: auto just in case
- Shrink and move ferris when possible
- Snapshot chapter 6 for nostarch
- Demonstrate variable as catch-all for match. Fixes rust-lang/book#1868.
- Improve the if let example to have a binding pattern. Fixes rust-lang/book#1401.
- Fixes typo (rust-lang/book#2816)
5 commits in c4644b427cbdaafc7a87be0ccdf5d8aaa07ac35f..cf0e151b7925a40f13fbc6573c6f97d5f94c7c17
2021-08-10 20:41:44 +0900 to 2021-08-22 11:47:02 -0300
- Fix typo “a Rc” → “an Rc” (rust-lang/rustc-dev-guide#1191)
- Expand THIR section with more details (rust-lang/rustc-dev-guide#1183)
- Remove docs for old -Z profile-queries flag
- update mdbook version to latest
- allow to quickly edit a page directly on github
Rollup merge of #88273 - jhpratt:update-iterator-docs, r=jyn514
Fix references to `ControlFlow` in docs
The `Iterator::for_each` method previously stated that it was not possible to use `break` and `continue` in it — this has been updated to acknowledge the stabilization of `ControlFlow`. Additionally, `ControlFlow` was referred to as `crate::ops::ControlFlow` which is not the correct path for an end user.
Rollup merge of #88226 - steffahn:an_rc, r=michaelwoerister
Fix typo “a Rc” → “an Rc” (and a few more)
After stumbling about it in the dev-guide, I’ve devided to eliminate all mentions of “a Rc”, replacing it with “an Rc”. E.g.
```plain
$ rg "(^|[^'])\ba\b[^\w=:]*\bRc"
compiler/rustc_data_structures/src/owning_ref/mod.rs
1149:/// Typedef of a owning reference that uses a `Rc` as the owner.
library/std/src/ffi/os_str.rs
919: /// Converts a [`OsString`] into a [`Rc`]`<OsStr>` without copying or allocating.
library/std/src/ffi/c_str.rs
961: /// Converts a [`CString`] into a [`Rc`]`<CStr>` without copying or allocating.
src/doc/rustc-dev-guide/src/query.md
61:are cheaply cloneable; insert a `Rc` if necessary).
src/doc/book/src/ch15-06-reference-cycles.md
72:decreases the reference count of the `a` `Rc<List>` instance from 2 to 1 as
library/alloc/src/rc.rs
1746: /// Converts a generic type `T` into a `Rc<T>`
```
_(the match in the book is a false positive)_
Since the dev-guide is a submodule, it’s getting a separate PR: rust-lang/rustc-dev-guide#1191
I’ve also gone ahead and done the same search for `RwLock` and hit a few cases in the `OwningRef` adaption. Then, I couldn’t keep the countless cases of “a owning …” or “a owner” unaddressed, which concludes this PR.
Rollup merge of #88218 - Aaron1011:missing-method-dyn, r=nagisa
Remove `Session.trait_methods_not_found`
Instead, avoid registering the problematic well-formed obligation
to begin with. This removes global untracked mutable state,
and avoids potential issues with incremental compilation.
Rollup merge of #88196 - asquared31415:named-asm-labels-refactor, r=Amanieu
Refactor `named_asm_labels` to a HIR lint
As discussed on #88169, the `named_asm_labels` lint could be moved to a HIR lint. That allows future lints or custom plugins or clippy lints to more easily access the `asm!` macro's data and create better error messages with the lints.
Rollup merge of #88157 - Icenowy:bootstrap-riscv64, r=Mark-Simulacrum
bootstrap.py: recognize riscv64 when auto-detect
The architecture auto-detect table has no entry for riscv64 (which rustc
uses riscv64gc for the first part of triplet, assuming it's a generic
Linux distro).
Add it to the table to allow riscv64 systems to bootstrap Rust.
Rollup merge of #88156 - steffahn:arc_make_mut_and_weak, r=Mark-Simulacrum
Adjust / fix documentation of `Arc::make_mut`
Related discussion in the users forum:
[Whatʼs this alleged difference between Arc::make_mut and Rc::make_mut? – The Rust Programming Language Forum](https://users.rust-lang.org/t/what-s-this-alleged-difference-between-arc-make-mut-and-rc-make-mut/63747?u=steffahn)
Also includes a small formatting improvement in the documentation of `Rc::make_mut`.
This PR makes the two documentations in question complete analogs. The previously claimed point in which one “differs from the behavior of” the other turns out to be incorrect, AFAIK.
One remaining inaccuracy: `Weak` pointers aren’t disassociated from the allocation but only from the contained value, i.e. in case of outstanding `Weak` pointers there still is a new allocation created, just the call to `.clone()` is avoided, instead the value is moved from one allocation to the other.
Rollup merge of #87944 - oconnor663:as_array_of_cells, r=scottmcm
add Cell::as_array_of_cells, similar to Cell::as_slice_of_cells
I'd like to propose adding `Cell::as_array_of_cells`, as a natural analog to `Cell::as_slice_of_cells`. I don't have a specific use case in mind, other than that supporting slices but not arrays feels like a gap. Do other folks agree with that intuition? Would this addition be substantial enough to need an RFC?
---
Previously, converting `&mut [T; N]` to `&[Cell<T>; N]` looks like this:
```rust
let array = &mut [1, 2, 3];
let cells: &[Cell<i32>; 3] = Cell::from_mut(&mut array[..])
.as_slice_of_cells()
.try_into()
.unwrap();
```
With this new helper method, it looks like this:
```rust
let array = &mut [1, 2, 3];
let cells = Cell::from_mut(array).as_array_of_cells();
```
bors [Wed, 25 Aug 2021 13:42:02 +0000 (13:42 +0000)]
Auto merge of #87937 - LeSeulArtichaut:active-if-let-guards, r=nagisa
Don't mark `if_let_guard` as an incomplete feature
I don't think there is any reason for `if_let_guard` to be an incomplete feature, and I think the reason they were marked in the first place was simply because they weren't implemented at all.
bors [Wed, 25 Aug 2021 10:58:43 +0000 (10:58 +0000)]
Auto merge of #85344 - cbeuw:remap-across-cwd, r=michaelwoerister
Correctly handle remapping from path containing the current directory with trailing paths
If we have a `auxiliary/lib.rs`, and we generate the metadata with `--remap-path-prefix $PWD/auxiliary=xyz`, the path to `$PWD/auxiliary/lib.rs` won't be correctly remapped in the metadata. This is because internally, path to the working directory itself and relative paths to files under the working directory are remapped separately (hence neither are affected since neither has `$PWD/auxiliary` as prefix), but the concatenation between the working directory and the relative path is not remapped. This PR fixes that.
bors [Wed, 25 Aug 2021 08:12:16 +0000 (08:12 +0000)]
Auto merge of #87875 - asquared31415:generic-lang-items, r=cjgillot
Improve detection of generics on lang items
Adds detection for the required generics for all lang items. Many lang items require an exact or minimum amount of generic arguments and if they don't exist, the compiler will ICE. This does not add any additional validation about bounds on generics or any other lang item restrictions.
bors [Wed, 25 Aug 2021 05:31:26 +0000 (05:31 +0000)]
Auto merge of #84333 - tmiasko:liveness-yield, r=tmandry
Improve liveness analysis for generators
Liveness analysis for generators assumes that execution always continues
normally after a yield point, not accounting for the fact that generator
could be dropped before completion.
If generators captures any variables by reference, those variables could
be used within a generator, or when the generator completes, but also
after each yield point in the case the generator is dropped.
Account for the case when generator is dropped after yielding, but
before running to the completion. This effectively considers all
variables captured by reference to be used after a yield point.
bors [Wed, 25 Aug 2021 02:17:41 +0000 (02:17 +0000)]
Auto merge of #88242 - bonega:allocation_range, r=oli-obk
Use custom wrap-around type instead of RangeInclusive
Two reasons:
1. More memory is allocated than necessary for `valid_range` in `Scalar`. The range is not used as an iterator and `exhausted` is never used.
2. `contains`, `count` etc. methods in `RangeInclusive` are doing very unhelpful(and dangerous!) things when used as a wrap-around range. - In general this PR wants to limit potentially confusing methods, that have a low probability of working.
Doing a local perf run, every metric shows improvement except for instructions.
Max-rss seem to have a very consistent improvement.
Mark Rousskov [Wed, 11 Aug 2021 17:17:21 +0000 (13:17 -0400)]
PGO for LLVM builds on x86_64-unknown-linux-gnu in CI
This shows up to 5% less instruction counts on multiple benchmarks, and up to
19% wins on the -j1 wall times for rustc self-compilation.
We can afford to spend the extra cycles building LLVM essentially once more for
the x86_64-unknown-linux-gnu CI build today. The builder finishes in around 50
minutes on average, and this adds just 10 more minutes. Given the sizeable
improvements in compiler performance, this is definitely worth it.
bors [Tue, 24 Aug 2021 17:41:24 +0000 (17:41 +0000)]
Auto merge of #87472 - inquisitivecrystal:stabilize-force-warn, r=Mark-Simulacrum
Stabilize and document `--force-warn`
This PR will stabilize and document the `--force-warn` command line option. It is currently a draft, pending an FCP.
I've taken the liberty of tidying up the lint level command line options a bit as part of this. The changes are quite minor and should only affect rustc's help output. I'm making them here because they're trivial and, in one case, necessary to unify the way `--force-warn` with the way the other options are displayed.
I also want to mention that `@rylev` has done a ton of work on moving this along and deserves most of the credit. I'm just the one who landed up writing this particular PR.
Ian Jackson [Tue, 24 Aug 2021 15:53:58 +0000 (16:53 +0100)]
io::ErrorKind: rationalise ordering in main enum
It is useful to keep some coherent structure to this ordering. In
particular, Other and Uncategorized should be next to each other, at
the end.
Also it seems to make sense to treat UnexpectedEof and OutOfMemory
specially, since they are not like the other errors (despite
OutOfMemory also being generatable by some OS errors).
So:
* Move Other to the end, just before Uncategorized
* Move Unsupported to between Interrupted and UnexpectedEof
* Add some comments documenting where to add things
Signed-off-by: Ian Jackson <ijackson@chiark.greenend.org.uk>
bors [Tue, 24 Aug 2021 12:13:37 +0000 (12:13 +0000)]
Auto merge of #87699 - ubamrein:use-iphone-deployment-target-for-llvm, r=petrochenkov
Allow specifying an deployment target version for all iOS llvm targets
Closes: https://github.com/rust-lang/rust/issues/79408
This pull requests adds the same procedure to define the iOS-version for the LLVM-target as was used for the simulator target and the desktop target.
This then closes the original problem mentioned in the above issue. The problem with incompatible bitcode remains, but is probably not easy fixable.
I realised that something is still not right. Try to fix that.
Tomasz Miąsko [Mon, 19 Apr 2021 00:00:00 +0000 (00:00 +0000)]
Improve liveness analysis for generators
Liveness analysis for generators assumes that execution always continues
normally after a yield point, not accounting for the fact that generator
could be dropped before completion.
If generators captures any variables by reference, those variables could
be used within a generator, or when the generator completes, but also
after each yield point in the case the generator is dropped.
Account for the case when generator is dropped after yielding, but
before running to the completion. This effectively considers all
variables captured by reference to be used after a yield point.
bors [Tue, 24 Aug 2021 03:58:22 +0000 (03:58 +0000)]
Auto merge of #87739 - Aaron1011:remove-used-attrs, r=wesleywiser
Remove `Session.used_attrs` and move logic to `CheckAttrVisitor`
Instead of updating global state to mark attributes as used,
we now explicitly emit a warning when an attribute is used in
an unsupported position. As a side effect, we are to emit more
detailed warning messages (instead of just a generic "unused" message).
`Session.check_name` is removed, since its only purpose was to mark
the attribute as used. All of the callers are modified to use
`Attribute.has_name`
Additionally, `AttributeType::AssumedUsed` is removed - an 'assumed
used' attribute is implemented by simply not performing any checks
in `CheckAttrVisitor` for a particular attribute.
We no longer emit unused attribute warnings for the `#[rustc_dummy]`
attribute - it's an internal attribute used for tests, so it doesn't
mark sense to treat it as 'unused'.
With this commit, a large source of global untracked state is removed.
bors [Tue, 24 Aug 2021 01:36:09 +0000 (01:36 +0000)]
Auto merge of #85556 - FabianWolff:issue-85071, r=estebank,jackh726
Warn about unreachable code following an expression with an uninhabited type
This pull request fixes #85071. The issue is that liveness analysis currently is "smarter" than reachability analysis when it comes to detecting uninhabited types: Unreachable code is detected during type checking, where full type information is not yet available. Therefore, the check for type inhabitedness is quite crude:
https://github.com/rust-lang/rust/blob/fc81ad22c453776de16acf9938976930cf8c9401/compiler/rustc_typeck/src/check/expr.rs#L202-L205
i.e. it only checks for `!`, but not other, non-trivially uninhabited types, such as empty enums, structs containing an uninhabited type, etc. By contrast, liveness analysis, which runs after type checking, can benefit from the more sophisticated `tcx.is_ty_uninhabited_from()`:
https://github.com/rust-lang/rust/blob/fc81ad22c453776de16acf9938976930cf8c9401/compiler/rustc_passes/src/liveness.rs#L981
https://github.com/rust-lang/rust/blob/fc81ad22c453776de16acf9938976930cf8c9401/compiler/rustc_passes/src/liveness.rs#L996
This can lead to confusing warnings when a variable is reported as unused, but the use of the variable is not reported as unreachable. For instance:
```rust
enum Foo {}
fn f() -> Foo {todo!()}
fn main() {
let x = f();
let _ = x;
}
```
currently leads to
```
warning: unused variable: `x`
--> t1.rs:5:9
|
5 | let x = f();
| ^ help: if this is intentional, prefix it with an underscore: `_x`
|
= note: `#[warn(unused_variables)]` on by default
warning: 1 warning emitted
```
which is confusing, because `x` _appears_ to be used in line 6. With my changes, I get:
```
warning: unreachable expression
--> t1.rs:6:13
|
5 | let x = f();
| --- any code following this expression is unreachable
6 | let _ = x;
| ^ unreachable expression
|
= note: `#[warn(unreachable_code)]` on by default
note: this expression has type `Foo`, which is uninhabited
--> t1.rs:5:13
|
5 | let x = f();
| ^^^
warning: unused variable: `x`
--> t1.rs:5:9
|
5 | let x = f();
| ^ help: if this is intentional, prefix it with an underscore: `_x`
|
= note: `#[warn(unused_variables)]` on by default
warning: 2 warnings emitted
```
My implementation is slightly inelegant because unreachable code warnings can now be issued in two different places (during type checking and during liveness analysis), but I think it is the solution with the least amount of unnecessary code duplication, given that the new warning integrates nicely with liveness analysis, where unreachable code is already implicitly detected for the purpose of finding unused variables.
bors [Mon, 23 Aug 2021 20:10:29 +0000 (20:10 +0000)]
Auto merge of #88265 - m-ou-se:rollup-soymv20, r=m-ou-se
Rollup of 6 pull requests
Successful merges:
- #87976 (Account for tabs when highlighting multiline code suggestions)
- #88174 (Clarify some wording in Rust 2021 lint docs)
- #88188 (Greatly improve limitation handling on parallel rustdoc GUI test run)
- #88230 (Fix typos “a”→“an”)
- #88232 (Add notes to macro-not-found diagnostics to point out how things with the same name were not a match.)
- #88259 (Do not mark `-Z thir-unsafeck` as unsound anymore)