Commit Graph

553 Commits

Author SHA1 Message Date
est31
0f4c81a1a9 Extend the irrefutable_let_patterns lint to let chains
Only look for complete suffixes or prefixes of irrefutable let patterns, so
that an irrefutable let pattern in a chain surrounded by refutable ones is
not linted, as it is an useful pattern.
2022-03-16 00:28:07 +01:00
Dylan DPC
13e889986d fix typos 2022-03-15 02:00:08 +01:00
Devin Ragotzy
492d8d7293 Fix rebase conflicts with stderr files 2022-03-12 15:38:44 -05:00
Devin Ragotzy
7ffb29d03c Only filter doc(hidden) fields/variants when not crate local 2022-03-12 15:16:11 -05:00
Nicholas Nethercote
ca5525d564 Improve AdtDef interning.
This commit makes `AdtDef` use `Interned`. Much the commit is tedious
changes to introduce getter functions. The interesting changes are in
`compiler/rustc_middle/src/ty/adt.rs`.
2022-03-11 13:31:24 +11:00
bors
d7b282b886 Auto merge of #94059 - b-naber:constantkind-val-transformation, r=lcnr
Treat constant values as mir::ConstantKind::Val

Another step that is necessary for the introduction of Valtrees: we don't want to treat `ty::Const` instances of kind `ty::ConstKind::Value` as `mir::ConstantKind::Ty` anymore.

r? `@oli-obk`
2022-03-10 05:53:59 +00:00
Matthias Krüger
ec09e70ee1
Rollup merge of #94739 - estebank:suggest-let-else, r=oli-obk
Suggest `if let`/`let_else` for refutable pat in `let`

r? `````@oli-obk`````
2022-03-09 23:14:11 +01:00
b-naber
40e4bd2d02 treat all mir::Constant values as ConstantKind::Val 2022-03-09 10:52:04 +01:00
bors
1eb72580d0 Auto merge of #94702 - b-naber:static-refs-mir, r=lcnr
Reinstate #93800

https://github.com/rust-lang/rust/pull/93800 caused a regression in an alt builder with parallel enabled. https://github.com/rust-lang/rust/pull/94205 reverted that PR because of the regression. For an unknown reason the regression has disappeared, so we reinstate the changes in https://github.com/rust-lang/rust/pull/93800 here.

r? `@Mark-Simulacrum`
2022-03-08 19:25:19 +00:00
Esteban Kuber
c3a998e82a Do not suggest let_else if no bindings would be introduced 2022-03-08 17:20:05 +00:00
Esteban Kuber
0d92752b8a Suggest if let/let_else for refutable pat in let 2022-03-08 16:32:08 +00:00
b-naber
d92df974fe treat literals in ExprKind::StaticRef as mir::ConstantKind::Val 2022-03-08 10:04:28 +01:00
Esteban Kuber
6f45f73adc Change wording of suggestion to add missing match arm 2022-03-08 00:20:41 +00:00
Esteban Kuber
ab4feea50d Point at uncovered variants in enum definition in note instead of a span_label
This makes the order of the output always consistent:

1. Place of the `match` missing arms
2. The `enum` definition span
3. The structured suggestion to add a fallthrough arm
2022-03-08 00:19:08 +00:00
Esteban Kuber
084ca79e7c When finding a match expr with multiple arms that requires more, suggest it
Given

```rust
match Some(42) {
    Some(0) => {}
    Some(1) => {}
}
```

suggest

```rust
match Some(42) {
    Some(0) => {}
    Some(1) => {}
    None | Some(_) => todo!(),
}
```
2022-03-08 00:18:24 +00:00
Esteban Kuber
2383858f34 When finding a match expr with a single arm that requires more, suggest it
Given

```rust
match Some(42) {
    Some(0) => {}
}
```

suggest

```rust
match Some(42) {
    Some(0) => {}
    None | Some(_) => todo!(),
}
```
2022-03-08 00:18:24 +00:00
Esteban Kuber
02a3830f24 When encountering a match expr with no arms, suggest it
Given

```rust
match Some(42) {}
```

suggest

```rust
match Some(42) { None | Some(_) => todo!(), }
```
2022-03-08 00:18:23 +00:00
mark
e489a94dee rename ErrorReported -> ErrorGuaranteed 2022-03-02 09:45:25 -06:00
Caio
fe94f78b9b 6 - Make more use of let_chains
Continuation of #94376.

cc #53667
2022-02-28 21:12:52 -03:00
Mark Rousskov
76b13c9eea Enable rustc_pass_by_value for Span 2022-02-25 08:00:53 -05:00
Mark Rousskov
22c3a71de1 Switch bootstrap cfgs 2022-02-25 08:00:52 -05:00
Eduard-Mihai Burtescu
b7e95dee65 rustc_errors: let DiagnosticBuilder::emit return a "guarantee of emission". 2022-02-23 06:38:52 +00:00
Eduard-Mihai Burtescu
02ff9e0aef Replace &mut DiagnosticBuilder, in signatures, with &mut Diagnostic. 2022-02-23 05:38:19 +00:00
bors
03a8cc7df1 Auto merge of #93505 - lcnr:substsref-vs-ty-list, r=michaelwoerister
safely `transmute<&List<Ty<'tcx>>, &List<GenericArg<'tcx>>>`

This PR has 3 relevant steps which are is split in distinct commits.

The first commit now interns `List<Ty<'tcx>>` and `List<GenericArg<'tcx>>` together, potentially reusing memory while allowing free conversions between these two using `List<Ty<'tcx>>::as_substs()` and `SubstsRef<'tcx>::try_as_type_list()`.

Using this, we then use `&'tcx List<Ty<'tcx>>` instead of a `SubstsRef<'tcx>` for tuple fields, simplifying a bunch of code.

Finally, as tuple fields and other generic arguments now use a different `TypeFoldable<'tcx>` impl, we optimize the impl for `List<Ty<'tcx>>` improving perf by slightly less than 1% in tuple heavy benchmarks.
2022-02-21 16:03:38 +00:00
lcnr
1245131a11 use List<Ty<'tcx>> for tuples 2022-02-21 07:09:11 +01:00
Mark Rousskov
9f76214854 Revert "Auto merge of #93800 - b-naber:static-initializers-mir-val, r=oli-obk"
This reverts commit a240ccd81c, reversing
changes made to 393fdc1048.

This PR was likely responsible for a relatively large regression in
dist-x86_64-msvc-alt builder times, from approximately 1.7 to 2.8 hours,
bringing that builder into the pool of the slowest builders we currently have.

This seems to be limited to the alt builder due to needing parallel-compiler
enabled, likely leading to slow LLVM compilation for some reason.
2022-02-20 21:56:20 -05:00
bors
45e2c2881d Auto merge of #93678 - steffahn:better_unsafe_diagnostics, r=nagisa
Improve `unused_unsafe` lint

I’m going to add some motivation and explanation below, particularly pointing the changes in behavior from this PR.

_Edit:_ Looking for existing issues, looks like this PR fixes #88260.

_Edit2:_ Now also contains code that closes #90776.
2022-02-20 21:15:11 +00:00
Frank Steffahn
8f8689fb31 Improve unused_unsafe lint
Main motivation: Fixes some issues with the current behavior. This PR is
more-or-less completely re-implementing the unused_unsafe lint; it’s also only
done in the MIR-version of the lint, the set of tests for the `-Zthir-unsafeck`
version no longer succeeds (and is thus disabled, see `lint-unused-unsafe.rs`).

On current nightly,
```rs
unsafe fn unsf() {}

fn inner_ignored() {
    unsafe {
        #[allow(unused_unsafe)]
        unsafe {
            unsf()
        }
    }
}
```

doesn’t create any warnings. This situation is not unrealistic to come by, the
inner `unsafe` block could e.g. come from a macro. Actually, this PR even
includes removal of one unused `unsafe` in the standard library that was missed
in a similar situation. (The inner `unsafe` coming from an external macro hides
    the warning, too.)

The reason behind this problem is how the check currently works:
* While generating MIR, it already skips nested unsafe blocks (i.e. unsafe
  nested in other unsafe) so that the inner one is always the one considered
  unused
* To differentiate the cases of no unsafe operations inside the `unsafe` vs.
  a surrounding `unsafe` block, there’s some ad-hoc magic walking up the HIR to
  look for surrounding used `unsafe` blocks.

There’s a lot of problems with this approach besides the one presented above.
E.g. the MIR-building uses checks for `unsafe_op_in_unsafe_fn` lint to decide
early whether or not `unsafe` blocks in an `unsafe fn` are redundant and ought
to be removed.
```rs
unsafe fn granular_disallow_op_in_unsafe_fn() {
    unsafe {
        #[deny(unsafe_op_in_unsafe_fn)]
        {
            unsf();
        }
    }
}
```
```
error: call to unsafe function is unsafe and requires unsafe block (error E0133)
  --> src/main.rs:13:13
   |
13 |             unsf();
   |             ^^^^^^ call to unsafe function
   |
note: the lint level is defined here
  --> src/main.rs:11:16
   |
11 |         #[deny(unsafe_op_in_unsafe_fn)]
   |                ^^^^^^^^^^^^^^^^^^^^^^
   = note: consult the function's documentation for information on how to avoid undefined behavior

warning: unnecessary `unsafe` block
  --> src/main.rs:10:5
   |
9  | unsafe fn granular_disallow_op_in_unsafe_fn() {
   | --------------------------------------------- because it's nested under this `unsafe` fn
10 |     unsafe {
   |     ^^^^^^ unnecessary `unsafe` block
   |
   = note: `#[warn(unused_unsafe)]` on by default

```
Here, the intermediate `unsafe` was ignored, even though it contains a unsafe
operation that is not allowed to happen in an `unsafe fn` without an additional `unsafe` block.

Also closures were problematic and the workaround/algorithms used on current
nightly didn’t work properly. (I skipped trying to fully understand what it was
supposed to do, because this PR uses a completely different approach.)
```rs
fn nested() {
    unsafe {
        unsafe { unsf() }
    }
}
```
```
warning: unnecessary `unsafe` block
  --> src/main.rs:10:9
   |
9  |     unsafe {
   |     ------ because it's nested under this `unsafe` block
10 |         unsafe { unsf() }
   |         ^^^^^^ unnecessary `unsafe` block
   |
   = note: `#[warn(unused_unsafe)]` on by default
```

vs

```rs
fn nested() {
    let _ = || unsafe {
        let _ = || unsafe { unsf() };
    };
}
```
```
warning: unnecessary `unsafe` block
 --> src/main.rs:9:16
  |
9 |     let _ = || unsafe {
  |                ^^^^^^ unnecessary `unsafe` block
  |
  = note: `#[warn(unused_unsafe)]` on by default

warning: unnecessary `unsafe` block
  --> src/main.rs:10:20
   |
10 |         let _ = || unsafe { unsf() };
   |                    ^^^^^^ unnecessary `unsafe` block
```

*note that this warning kind-of suggests that **both** unsafe blocks are redundant*

--------------------------------------------------------------------------------

I also dislike the fact that it always suggests keeping the outermost `unsafe`.
E.g. for
```rs
fn granularity() {
    unsafe {
        unsafe { unsf() }
        unsafe { unsf() }
        unsafe { unsf() }
    }
}
```
I prefer if `rustc` suggests removing the more-course outer-level `unsafe`
instead of the fine-grained inner `unsafe` blocks, which it currently does on nightly:
```
warning: unnecessary `unsafe` block
  --> src/main.rs:10:9
   |
9  |     unsafe {
   |     ------ because it's nested under this `unsafe` block
10 |         unsafe { unsf() }
   |         ^^^^^^ unnecessary `unsafe` block
   |
   = note: `#[warn(unused_unsafe)]` on by default

warning: unnecessary `unsafe` block
  --> src/main.rs:11:9
   |
9  |     unsafe {
   |     ------ because it's nested under this `unsafe` block
10 |         unsafe { unsf() }
11 |         unsafe { unsf() }
   |         ^^^^^^ unnecessary `unsafe` block

warning: unnecessary `unsafe` block
  --> src/main.rs:12:9
   |
9  |     unsafe {
   |     ------ because it's nested under this `unsafe` block
...
12 |         unsafe { unsf() }
   |         ^^^^^^ unnecessary `unsafe` block
```

--------------------------------------------------------------------------------

Needless to say, this PR addresses all these points. For context, as far as my
understanding goes, the main advantage of skipping inner unsafe blocks was that
a test case like
```rs
fn top_level_used() {
    unsafe {
        unsf();
        unsafe { unsf() }
        unsafe { unsf() }
        unsafe { unsf() }
    }
}
```
should generate some warning because there’s redundant nested `unsafe`, however
every single `unsafe` block _does_ contain some statement that uses it. Of course
this PR doesn’t aim change the warnings on this kind of code example, because
the current behavior, warning on all the inner `unsafe` blocks, makes sense in this case.

As mentioned, during MIR building all the unsafe blocks *are* kept now, and usage
is attributed to them. The way to still generate a warning like
```
warning: unnecessary `unsafe` block
  --> src/main.rs:11:9
   |
9  |     unsafe {
   |     ------ because it's nested under this `unsafe` block
10 |         unsf();
11 |         unsafe { unsf() }
   |         ^^^^^^ unnecessary `unsafe` block
   |
   = note: `#[warn(unused_unsafe)]` on by default

warning: unnecessary `unsafe` block
  --> src/main.rs:12:9
   |
9  |     unsafe {
   |     ------ because it's nested under this `unsafe` block
...
12 |         unsafe { unsf() }
   |         ^^^^^^ unnecessary `unsafe` block

warning: unnecessary `unsafe` block
  --> src/main.rs:13:9
   |
9  |     unsafe {
   |     ------ because it's nested under this `unsafe` block
...
13 |         unsafe { unsf() }
   |         ^^^^^^ unnecessary `unsafe` block
```

in this case is by emitting a `unused_unsafe` warning for all of the `unsafe`
blocks that are _within a **used** unsafe block_.

The previous code had a little HIR traversal already anyways to collect a set of
all the unsafe blocks (in order to afterwards determine which ones are unused
afterwards). This PR uses such a traversal to do additional things including logic
like _always_ warn for an `unsafe` block that’s inside of another **used**
unsafe block. The traversal is expanded to include nested closures in the same go,
this simplifies a lot of things.

The whole logic around `unsafe_op_in_unsafe_fn` is a little complicated, there’s
some test cases of corner-cases in this PR. (The implementation involves
differentiating between whether a used unsafe block was used exclusively by
operations where `allow(unsafe_op_in_unsafe_fn)` was active.) The main goal was
to make sure that code should compile successfully if all the `unused_unsafe`-warnings
are addressed _simultaneously_ (by removing the respective `unsafe` blocks)
no matter how complicated the patterns of `unsafe_op_in_unsafe_fn` being
disallowed and allowed throughout the function are.

--------------------------------------------------------------------------------

One noteworthy design decision I took here: An `unsafe` block
with `allow(unused_unsafe)` **is considered used** for the purposes of
linting about redundant contained unsafe blocks. So while
```rs

fn granularity() {
    unsafe { //~ ERROR: unnecessary `unsafe` block
        unsafe { unsf() }
        unsafe { unsf() }
        unsafe { unsf() }
    }
}
```
warns for the outer `unsafe` block,
```rs

fn top_level_ignored() {
    #[allow(unused_unsafe)]
    unsafe {
        #[deny(unused_unsafe)]
        {
            unsafe { unsf() } //~ ERROR: unnecessary `unsafe` block
            unsafe { unsf() } //~ ERROR: unnecessary `unsafe` block
            unsafe { unsf() } //~ ERROR: unnecessary `unsafe` block
        }
    }
}
```
warns on the inner ones.
2022-02-20 21:00:12 +01:00
bors
523a1b1d38 Auto merge of #94062 - Mark-Simulacrum:drop-print-cfg, r=oli-obk
Move ty::print methods to Drop-based scope guards

Primary goal is reducing codegen of the TLS access for each closure, which shaves ~3 seconds of bootstrap time over rustc as a whole.
2022-02-20 18:12:59 +00:00
est31
2ef8af6619 Adopt let else in more places 2022-02-19 17:27:43 +01:00
Mark Rousskov
9763486034 Move ty::print methods to Drop-based scope guards 2022-02-16 17:24:23 -05:00
b-naber
fff06e5edc use AllocId and Ty in ExprKind::StaticRef and delay ConstValue construction 2022-02-15 21:18:33 +01:00
b-naber
5e0fab6da5 use ConstantKind::Val in StaticRef 2022-02-15 21:10:42 +01:00
Nicholas Nethercote
a95fb8b150 Overhaul Const.
Specifically, rename the `Const` struct as `ConstS` and re-introduce `Const` as
this:
```
pub struct Const<'tcx>(&'tcx Interned<ConstS>);
```
This now matches `Ty` and `Predicate` more closely, including using
pointer-based `eq` and `hash`.

Notable changes:
- `mk_const` now takes a `ConstS`.
- `Const` was copy, despite being 48 bytes. Now `ConstS` is not, so need a
  we need separate arena for it, because we can't use the `Dropless` one any
  more.
- Many `&'tcx Const<'tcx>`/`&Const<'tcx>` to `Const<'tcx>` changes
- Many `ct.ty` to `ct.ty()` and `ct.val` to `ct.val()` changes.
- Lots of tedious sigil fiddling.
2022-02-15 16:19:59 +11:00
Nicholas Nethercote
7024dc523a Overhaul RegionKind and Region.
Specifically, change `Region` from this:
```
pub type Region<'tcx> = &'tcx RegionKind;
```
to this:
```
pub struct Region<'tcx>(&'tcx Interned<RegionKind>);
```

This now matches `Ty` and `Predicate` more closely.

Things to note
- Regions have always been interned, but we haven't been using pointer-based
  `Eq` and `Hash`. This is now happening.
- I chose to impl `Deref` for `Region` because it makes pattern matching a lot
  nicer, and `Region` can be viewed as just a smart wrapper for `RegionKind`.
- Various methods are moved from `RegionKind` to `Region`.
- There is a lot of tedious sigil changes.
- A couple of types like `HighlightBuilder`, `RegionHighlightMode` now have a
  `'tcx` lifetime because they hold a `Ty<'tcx>`, so they can call `mk_region`.
- A couple of test outputs change slightly, I'm not sure why, but the new
  outputs are a little better.
2022-02-15 16:08:52 +11:00
Nicholas Nethercote
e9a0c429c5 Overhaul TyS and Ty.
Specifically, change `Ty` from this:
```
pub type Ty<'tcx> = &'tcx TyS<'tcx>;
```
to this
```
pub struct Ty<'tcx>(Interned<'tcx, TyS<'tcx>>);
```
There are two benefits to this.
- It's now a first class type, so we can define methods on it. This
  means we can move a lot of methods away from `TyS`, leaving `TyS` as a
  barely-used type, which is appropriate given that it's not meant to
  be used directly.
- The uniqueness requirement is now explicit, via the `Interned` type.
  E.g. the pointer-based `Eq` and `Hash` comes from `Interned`, rather
  than via `TyS`, which wasn't obvious at all.

Much of this commit is boring churn. The interesting changes are in
these files:
- compiler/rustc_middle/src/arena.rs
- compiler/rustc_middle/src/mir/visit.rs
- compiler/rustc_middle/src/ty/context.rs
- compiler/rustc_middle/src/ty/mod.rs

Specifically:
- Most mentions of `TyS` are removed. It's very much a dumb struct now;
  `Ty` has all the smarts.
- `TyS` now has `crate` visibility instead of `pub`.
- `TyS::make_for_test` is removed in favour of the static `BOOL_TY`,
  which just works better with the new structure.
- The `Eq`/`Ord`/`Hash` impls are removed from `TyS`. `Interned`s impls
  of `Eq`/`Hash` now suffice. `Ord` is now partly on `Interned`
  (pointer-based, for the `Equal` case) and partly on `TyS`
  (contents-based, for the other cases).
- There are many tedious sigil adjustments, i.e. adding or removing `*`
  or `&`. They seem to be unavoidable.
2022-02-15 16:03:24 +11:00
Ellen
e81e09a24e change to a struct variant 2022-02-12 11:23:53 +00:00
Michael Goulet
a431174c23 add tainted_by_errors to mir::Body 2022-02-11 12:45:51 -08:00
Oli Scherer
d54195db22 Revert "Auto merge of #92007 - oli-obk:lazy_tait2, r=nikomatsakis"
This reverts commit e7cc3bddbe, reversing
changes made to 734368a200.
2022-02-11 07:18:06 +00:00
Camille GILLOT
6c2ee885e6 Ensure that queries only return Copy types. 2022-02-09 20:07:38 +01:00
bors
e7cc3bddbe Auto merge of #92007 - oli-obk:lazy_tait2, r=nikomatsakis
Lazy type-alias-impl-trait

Previously opaque types were processed by

1. replacing all mentions of them with inference variables
2. memorizing these inference variables in a side-table
3. at the end of typeck, resolve the inference variables in the side table and use the resolved type as the hidden type of the opaque type

This worked okayish for `impl Trait` in return position, but required lots of roundabout type inference hacks and processing.

This PR instead stops this process of replacing opaque types with inference variables, and just keeps the opaque types around.
Whenever an opaque type `O` is compared with another type `T`, we make the comparison succeed and record `T` as the hidden type. If `O` is compared to `U` while there is a recorded hidden type for it, we grab the recorded type (`T`) and compare that against `U`. This makes implementing

* https://github.com/rust-lang/rfcs/pull/2515

much simpler (previous attempts on the inference based scheme were very prone to ICEs and general misbehaviour that was not explainable except by random implementation defined oddities).

r? `@nikomatsakis`

fixes #93411
fixes #88236
2022-02-07 23:40:26 +00:00
Yuki Okushi
7712dfd46e
Rollup merge of #93589 - est31:option_then, r=cjgillot
Use Option::then in two places
2022-02-03 22:20:27 +09:00
est31
670f5c6ef3 More let_else adoptions 2022-02-02 17:11:01 +01:00
Oli Scherer
0f6e06b7c0 Lazily resolve type-alias-impl-trait defining uses
by using an opaque type obligation to bubble up comparisons between opaque types and other types

Also uses proper obligation causes so that the body id works, because out of some reason nll uses body ids for logic instead of just diagnostics.
2022-02-02 15:40:11 +00:00
est31
08be313feb Use Option::then in two places 2022-02-02 16:10:16 +01:00
lcnr
a1a30f7548 add a rustc::query_stability lint 2022-02-01 10:15:59 +01:00
Tomasz Miąsko
35b5daaaf8 Check the number of arguments first in is_recursive_call 2022-01-29 23:00:54 +01:00
Tomasz Miąsko
10b722cc79 Ignore unwinding edges when checking for unconditional recursion
The unconditional recursion lint determines if all execution paths
eventually lead to a self-recursive call.

The implementation always follows unwinding edges which limits its
practical utility. For example, it would not lint function `f` because a
call to `g` might unwind. It also wouldn't lint function `h` because an
overflow check preceding the self-recursive call might unwind:

```rust
pub fn f() {
    g();
    f();
}

pub fn g() { /* ... */ }

pub fn h(a: usize) {
  h(a + 1);
}
```

To avoid the issue, assume that terminators that might continue
execution along non-unwinding edges do so.
2022-01-26 13:46:01 +01:00
Matthias Krüger
ab19d4a515
Rollup merge of #93046 - est31:let_else, r=davidtwco
Use let_else in even more places

Followup of #89933, #91018, #91481.
2022-01-21 22:03:17 +01:00
Cameron Steffen
b11733534d Remove a span from hir::ExprKind::MethodCall 2022-01-21 07:48:10 -06:00