Migrate in-tree crates to 2021
This replaces #89075 (cherry picking some of the commits from there), and closes#88637 and fixes#89074.
It excludes a migration of the library crates for now (see tidy diff) because we have some pending bugs around macro spans to fix there.
I instrumented bootstrap during the migration to make sure all crates moved from 2018 to 2021 had the compatibility warnings applied first.
Originally, the intent was to support cargo fix --edition within bootstrap, but this proved fairly difficult to pull off. We'd need to architect the check functionality to support running cargo check and cargo fix within the same x.py invocation, and only resetting sysroots on check. Further, it was found that cargo fix doesn't behave too well with "not quite workspaces", such as Clippy which has several crates. Bootstrap runs with --manifest-path ... for all the tools, and this makes cargo fix only attempt migration for that crate. We can't use e.g. --workspace due to needing to maintain sysroots for different phases of compilation appropriately.
It is recommended to skip the mass migration of Cargo.toml's to 2021 for review purposes; you can also use `git diff d6cd2c6c87 -I'^edition = .20...$'` to ignore the edition = 2018/21 lines in the diff.
rustc_codegen_llvm: make sse4.2 imply crc32 for LLVM 14
This fixes compiling things like the `snap` crate after
https://reviews.llvm.org/D105462. I added a test that verifies the
additional attribute gets specified, and confirmed that I can build
cargo with both LLVM 13 and 14 with this change applied.
r? `@nagisa` cc `@nikic`
Don't use projection cache or candidate cache in intercrate mode
Fixes#88969
It appears that *just* disabling the evaluation cache (in #88994)
leads to other issues involving intercrate mode caching. I suspect
that since we now always end up performing the full evaluation
in intercrate mode, we end up 'polluting' the candidate and projection
caches with results that depend on being in intercrate mode in some way.
Previously, we might have hit a cached evaluation (stored during
non-intercrate mode), and skipped doing this extra work in
intercrate mode.
The whole situation with intercrate mode caching is turning into
a mess. Ideally, we would remove intercrate mode entirely - however,
this might require waiting on Chalk.
Register normalization obligations instead of immediately normalizing in opaque type instantiation
For lazy TAIT we will need to instantiate opaque types from within `rustc_infer`, which cannot invoke normalization methods (they are in `rustc_trait_resolution`). So before we move the logic over to `rustc_infer`, we need make sure no normalization happens anymore. This PR resolves that by just registering normalization obligations and continuing.
This PR is best reviewed commit by commit
I also included f7ad36e which is just an independent cleanup that touches the same code and reduces diagnostics noise a bit
r? `@nikomatsakis` cc `@spastorino`
Lower only one HIR owner at a time
Based on https://github.com/rust-lang/rust/pull/83723
Additional diff is here: https://github.com/cjgillot/rust/compare/ownernode...lower-mono
Lowering is very tangled and has a tendency to intertwine the transformation of different items. This PR aims at simplifying the logic by:
- moving global analyses to the resolver (item_generics_num_lifetimes, proc_macros, trait_impls);
- removing a few special cases (non-exported macros and use statements);
- restricting the amount of available information at any one time;
- avoiding back-and-forth between different owners: an item must now be lowered all at once, and its parent cannot refer to its nodes.
I also removed the sorting of bodies by span. The diagnostic ordering changes marginally, since definitions are pretty much sorted already according to the AST. This uncovered a subtlety in thir-unsafeck.
(While these items could logically be in different PRs, the dependency between commits and the amount of conflicts force a monolithic PR.)
This also adjusts the lint docs generation to accept (and ignore) an allow
attribute, rather than expecting the documentation to be immediately followed by
the lint name.
Suggest replacing braces for brackets on array-esque invalid block expr
Newcomers may write `{1, 2, 3}` for making arrays, and the current error message is not informative enough to quickly convince them what is needed to fix the error.
This PR implements a diagnostic for this case, and its output looks like this:
```text
error: this code is interpreted as a block expression, not an array
--> src/lib.rs:1:22
|
1 | const FOO: [u8; 3] = {
| ______________________^
2 | | 1, 2, 3
3 | | };
| |_^
|
= note: to define an array, one would use square brackets instead of curly braces
help: try using [] instead of {}
|
1 | const FOO: [u8; 3] = [
2 | 1, 2, 3
3 | ];
|
```
Fix#87672
Fixes#88969
It appears that *just* disabling the evaluation cache (in #88994)
leads to other issues involving intercrate mode caching. I suspect
that since we now always end up performing the full evaluation
in intercrate mode, we end up 'polluting' the candidate and projection
caches with results that depend on being in intercrate mode in some way.
Previously, we might have hit a cached evaluation (stored during
non-intercrate mode), and skipped doing this extra work in
intercrate mode.
The whole situation with intercrate mode caching is turning into
a mess. Ideally, we would remove intercrate mode entirely - however,
this might require waiting on Chalk.
This fixes compiling things like the `snap` crate after
https://reviews.llvm.org/D105462. I added a test that verifies the
additional attribute gets specified, and confirmed that I can build
cargo with both LLVM 13 and 14 with this change applied.
This just applies the suggested fixes from the compatibility warnings,
leaving any that are in practice spurious in. This is primarily intended to
provide a starting point to identify possible fixes to the migrations (e.g., by
avoiding spurious warnings).
A secondary commit cleans these up where they are false positives (as is true in
many of the cases).
Add initial support for m68k
This patch series adds initial support for m68k making use of the new M68k
backend introduced with LLVM-13. Additional changes will be needed to be
able to actually use the backend for this target.
Add `ConstraintCategory::Usage` for handling aggregate construction
In some cases, we emit borrowcheck diagnostics pointing
at a particular field expression in a struct expression
(e.g. `MyStruct { field: my_expr }`). However, this
behavior currently relies on us choosing the
`ConstraintCategory::Boring` with the 'correct' span.
When adding additional variants to `ConstraintCategory`,
(or changing existing usages away from `ConstraintCategory::Boring`),
the current behavior can easily get broken, since a non-boring
constraint will get chosen over a boring one.
To make the diagnostic output less fragile, this commit
adds a `ConstraintCategory::Usage` variant. We use this variant
for the temporary assignments created for each field of
an aggregate we are constructing.
Using this new variant, we can emit a message mentioning
"this usage", emphasizing the fact that the error message
is related to the specific use site (in the struct expression).
This is preparation for additional work on improving NLL error messages
(see #57374)
Querify `FnAbi::of_{fn_ptr,instance}` as `fn_abi_of_{fn_ptr,instance}`.
*Note: opening this PR as draft because it's based on #88499*
This more or less replicates the `LayoutOf::layout_of` setup from #88499, to replace `FnAbi::of_{fn_ptr,instance}` with `FnAbiOf::fn_abi_of_{fn_ptr,instance}`, and also route them through queries (which `layout_of` has used for a while).
The two changes at the use sites (other than the names) are:
* return type is now wrapped in `&'tcx`
* the value *is* interned, which may affect performance
* the `extra_args` list is now an interned `&'tcx ty::List<Ty<'tcx>>`
* should be cheap (it's empty for anything other than C variadics)
Theoretically, a `FnAbiOfHelpers` implementer could choose to keep the `Result<...>` instead of eagerly erroring, but the only existing users of these APIs are codegen backends, so they don't (want to) take advantage of this.
At least miri could make use of this, since it prefers propagating errors (it "just" doesn't use `FnAbi` yet - cc `@RalfJung).`
The way this is done is probably less efficient than what is possible, because the queries handle the correctness-oriented API (i.e. the split into `fn` pointers vs instances), whereas a lower-level query could end up with more reuse between different instances with identical signatures.
r? `@nagisa` cc `@oli-obk` `@bjorn3`
Convert `debug_assert` to `assert` in `CachingSourceMapView`
I suspect that there's a bug somewhere in this code, which is
leading to the `predicates_of` ICE being seen in #89035
Gather module items after lowering.
This avoids having a non-local analysis inside lowering.
By implementing `hir_module_items` using a visitor, we make sure that iterations and visitors are consistent.
Newcomers may write `{1, 2, 3}` for making arrays, and the current error
message is not informative enough to quickly convince them what is
needed to fix the error.
This PR implements a diagnostic for this case, and its output looks like
this:
```text
error: this code is interpreted as a block expression, not an array
--> src/lib.rs:1:22
|
1 | const FOO: [u8; 3] = {
| ______________________^
2 | | 1, 2, 3
3 | | };
| |_^
|
= note: to define an array, one would use square brackets instead of curly braces
help: try using [] instead of {}
|
1 | const FOO: [u8; 3] = [
2 | 1, 2, 3
3 | ];
|
```
Fix#87672
Suggest better place to add call parentheses for method expressions wrapped in parentheses
I wanted to improve the suggestion a bit to both remove the wrapping parentheses **and** add call parentheses by both calling `suggest_method_call` and using `multipart_suggestion`. But I very quickly ran into a problem where multiple overlapping machine applicable suggestions cannot be properly applied together. So I applied the suggestion from the issue and only added the call parentheses directly after the expression.
Fixes: https://github.com/rust-lang/rust/issues/89044
Add a separate error for `dyn Trait` in `const fn`
Previously "trait bounds other than `Sized` on const fn parameters are unstable" error was used for both trait bounds (`<T: Trait>`) and trait objects (`dyn Trait`). This was pretty confusing.
This PR adds a separate error for trait objects: "trait objects in const fn are unstable". The error for trait bounds is otherwise intact.
This is follow up to #88907
r? ``@estebank``
``@rustbot`` label: +A-diagnostics
Fix linting when trailing macro expands to a trailing semi
When a macro is used in the trailing expression position of a block
(e.g. `fn foo() { my_macro!() }`), we currently parse it as an
expression, rather than a statement. As a result, we ended up
using the `NodeId` of the containing statement as our `lint_node_id`,
even though we don't normally do this for macro calls.
If such a macro expands to an expression with a `#[cfg]` attribute,
then the trailing statement can get removed entirely. This lead to
an ICE, since we were usng the `NodeId` of the expression to emit
a lint.
Ths commit makes us skip updating `lint_node_id` when handling
a macro in trailing expression position. This will cause us to
lint at the closest parent of the macro call.
Suggest replacing an inexisting field for an unmentioned field
Fix#87938
This PR adds a suggestion to replace an inexisting field for an
unmentioned field. Given the following code:
```rust
enum Foo {
Bar { alpha: u8, bravo: u8, charlie: u8 },
}
fn foo(foo: Foo) {
match foo {
Foo::Bar {
alpha,
beta, // `bravo` miswritten as `beta` here.
charlie,
} => todo!(),
}
}
```
the compiler now emits the error messages below.
```text
error[E0026]: variant `Foo::Bar` does not have a field named `beta`
--> src/lib.rs:9:13
|
9 | beta, // `bravo` miswritten as `beta` here.
| ^^^^
| |
| variant `Foo::Bar` does not have this field
| help: `Foo::Bar` has a field named `bravo`: `bravo`
```
Note that this suggestion is available iff the number of inexisting
fields and unmentioned fields are both 1.
Propagate coercion cause into `try_coerce`
Currently, `coerce_inner` discards its `ObligationCause`
when calling `try_coerce`. This interfers with other
diagnostc improvements I'm working on, since we will lose
the original span by the time the actual coercion occurs.
Additionally, we now use the span of the trailing expression
(rather than the span of the entire function) when performing
a coercion in `check_return_expr`. This currently has no visible
effect on any of the unit tests, but will unblock future
diagnostic improvements.
Start block is not allowed to have basic block predecessors
* The MIR validator is extended to detect potential violations.
* The start block has no predecessors after building MIR, so no changes are required there.
* The SimplifyCfg could previously violate this requirement when collapsing goto chains, so transformation is disabled for the start block, which also substantially simplifies the implementation.
* The LLVM function entry block also must not have basic block predecessors. Previously, to ensure that code generation had to perform necessary adjustments. This now became unnecessary.
The motivation behind the change is to align with analogous requirement in LLVM, and to avoid potential latent bugs like the one reported in #88043.
Disable the evaluation cache when in intercrate mode
It's possible to use the same `InferCtxt` with both
an intercrate and non-intercrate `SelectionContext`. However,
the local (inferctxt) evaluation cache is not aware of this
distinction, so this kind of `InferCtxt` re-use will pollute
the cache wth bad results.
This commit avoids the issue by disabling the evaluation cache
entirely during intercrate mode.
Simplify lazy DefPathHash decoding by using an on-disk hash table.
This PR simplifies the logic around mapping `DefPathHash` values encountered during incremental compilation to valid `DefId`s in the current session. It is able to do so by using an on-disk hash table encoding that allows for looking up values directly, i.e. without deserializing the entire table.
The main simplification comes from not having to keep track of `DefPathHashes` being used during the compilation session.
Skip single use lifetime lint for generated opaque types
Fix: #77175
The opaque type generated by the desugaring process of an async function uses the lifetimes defined by the originating function. The DefId for the lifetimes in the opaque type are different from the ones in the originating async function - as they should be, as far as I understand, and could therefore be considered a single use lifetimes, this causes the single_use_lifetimes lint to fail compilation if explicitly denied. This fix skips the lint for lifetimes used only once in generated opaque types for an async function that are declared in the parent async function definition.
More info in the comments on the original issue: 1 and 2
