simplify code of finding arg index in `opt_const_param_of`
From the FIXME in the impl of `opt_const_param_of`. Part of the code is simplified by blending two iterator statements and using `let...else` statement.
Ensure we never consider the null pointer dereferencable
This replaces the checks that are being removed in https://github.com/rust-lang/rust/pull/97188. Those checks were too early and hence incorrect.
`SourceFile::lines` is a big part of metadata. It's stored in a compressed form
(a difference list) to save disk space. Decoding it is a big fraction of
compile time for very small crates/programs.
This commit introduces a new type `SourceFileLines` which has a `Lines`
form and a `Diffs` form. The latter is used when the metadata is first
read, and it is only decoded into the `Lines` form when line data is
actually needed. This avoids the decoding cost for many files,
especially in `std`. It's a performance win of up to 15% for tiny
crates/programs where metadata decoding is a high part of compilation
costs.
A `Lock` is needed because the methods that access lines data (which can
trigger decoding) take `&self` rather than `&mut self`. To allow for this,
`SourceFile::lines` now takes a `FnMut` that operates on the lines slice rather
than returning the lines slice.
This commit adds an alternative content boxing syntax,
and uses it inside alloc.
The usage inside the very performance relevant code in
liballoc is the only remaining relevant usage of box syntax
in the compiler (outside of tests, which are comparatively
easy to port).
box syntax was originally designed to be used by all Rust
developers. This introduces a replacement syntax more tailored
to only being used inside the Rust compiler, and with it,
lays the groundwork for eventually removing box syntax.
Rollup of 6 pull requests
Successful merges:
- #89685 (refactor: VecDeques Iter fields to private)
- #97172 (Optimize the diagnostic generation for `extern unsafe`)
- #97395 (Miri call ABI check: ensure type size+align stay the same)
- #97431 (don't do `Sized` and other return type checks on RPIT's real type)
- #97555 (Source code page: line number click adds `NaN`)
- #97558 (Fix typos in comment)
Failed merges:
r? `@ghost`
`@rustbot` modify labels: rollup
don't do `Sized` and other return type checks on RPIT's real type
Fixes an ICE where we're doing `Sized` check against the RPIT's real type, instead of against the opaque type. This differs from what we're doing in MIR typeck, which causes ICE #97226.
This regressed in #96516 -- this adjusts that fix to be a bit more conservative. That PR was backported and thus the ICE is also present in stable. Not sure if it's worth to beta and/or stable backport, probably not the latter but I could believe the former.
r? `@oli-obk`
cc: another attempt to fix this ICE #97413. I believe this PR addresses the root cause.
Miri call ABI check: ensure type size+align stay the same
We should almost certainly not accept calls where caller and callee disagree on the size or alignment of the type.
The checks we do *almost* imply that, except that `ScalarPair` types can have `repr(align)` and thus differ in size/align even when they are pairs of the same primitive type.
r? ``@oli-obk``
Optimize the diagnostic generation for `extern unsafe`
This PR does the following about diagnostic generation when parsing foreign mod:
1. Fixes the FIXME about avoiding depending on the error message text.
2. Continue parsing when `unsafe` is followed by `{` (just like `unsafe extern {...}`).
3. Add test case.
errors: simplify referring to fluent attributes
To render the message of a Fluent attribute, the identifier of the Fluent message must be known. `DiagnosticMessage::FluentIdentifier` contains both the message's identifier and optionally the identifier of an attribute. Generated constants for each attribute would therefore need to be named uniquely (amongst all error messages) or be able to refer to only the attribute identifier which will be combined with a message identifier later. In this commit, the latter strategy is implemented as part of the `Diagnostic` type's functions for adding subdiagnostics of various kinds.
r? `@oli-obk`
Add validation layer for Derefer
_Follow up work to #96549#96116#95857 #95649_
This adds validation for Derefer making sure it is always the first projection.
r? rust-lang/mir-opt
To render the message of a Fluent attribute, the identifier of the
Fluent message must be known. `DiagnosticMessage::FluentIdentifier`
contains both the message's identifier and optionally the identifier of
an attribute. Generated constants for each attribute would therefore
need to be named uniquely (amongst all error messages) or be able to
refer to only the attribute identifier which will be combined with a
message identifier later. In this commit, the latter strategy is
implemented as part of the `Diagnostic` type's functions for adding
subdiagnostics of various kinds.
Signed-off-by: David Wood <david.wood@huawei.com>
Ensure source file present when calculating max line number
Resubmission of #89268, fixes#71363
The behavior difference of `simulate-remapped-rust-src-base` is not something we should take into account here, so limiting targets to run the test makes sense, I think.
r? `@davidtwco,` and `@estebank,` you might be interested in this change
Replace `#[default_method_body_is_const]` with `#[const_trait]`
pulled out of #96077
related issues: #67792 and #92158
cc `@fee1-dead`
This is groundwork to only allowing `impl const Trait` for traits that are marked with `#[const_trait]`. This is necessary to prevent adding a new default method from becoming a breaking change (as it could be a non-const fn).
Finish bumping stage0
It looks like the last time had left some remaining cfg's -- which made me think
that the stage0 bump was actually successful. This brings us to a released 1.62
beta though.
This now brings us to cfg-clean, with the exception of check-cfg-features in bootstrap;
I'd prefer to leave that for a separate PR at this time since it's likely to be more tricky.
cc https://github.com/rust-lang/rust/pull/97147#issuecomment-1132845061
r? `@pietroalbini`
Prepare Rust for opaque pointers
Fix one codegen bug with opaque pointers, and update our IR tests to accept both typed pointer and opaque pointer IR. This is a bit annoying, but unavoidable if we want decent test coverage on both LLVM 14 and LLVM 15.
This prepares Rust for when LLVM will enable opaque pointers by default.
Rollup of 5 pull requests
Successful merges:
- #96950 (Add regression test for #96395)
- #97028 (Add support for embedding pretty printers via `#[debugger_visualizer]` attribute)
- #97478 (Remove FIXME on `ExtCtxt::fn_decl()`)
- #97479 (Make some tests check-pass)
- #97482 (ptr::invalid is not equivalent to a int2ptr cast)
Failed merges:
r? `@ghost`
`@rustbot` modify labels: rollup
Remove FIXME on `ExtCtxt::fn_decl()`
`ExtCtxt::fn_decl()` is used like `self.fn_decl(..)` or `self.cx.fn_decl(..)`, coverting it to an assoc fn, for example, makes it inconvenience (e.g. `self.cx.fn_decl(..)` would be longer to represent). Given that, it doesn't seem a "FIXME" thing and unused `self` is okay, I think.
Add support for embedding pretty printers via `#[debugger_visualizer]` attribute
Initial support for [RFC 3191](https://github.com/rust-lang/rfcs/pull/3191) in PR https://github.com/rust-lang/rust/pull/91779 was scoped to supporting embedding NatVis files using a new attribute. This PR implements the pretty printer support as stated in the RFC mentioned above.
This change includes embedding pretty printers in the `.debug_gdb_scripts` just as the pretty printers for rustc are embedded today. Also added additional tests for embedded pretty printers. Additionally cleaned up error checking so all error checking is done up front regardless of the current target.
RFC: https://github.com/rust-lang/rfcs/pull/3191
Update to rebased rustc-rayon 0.4
In rayon-rs/rayon#938, miri uncovered a race in `rustc-rayon-core` that had already been fixed in the regular `rayon-core`. I have now rebased that fork onto the latest rayon branch, and published as 0.4. I also updated `indexmap` to bump the dependency.
`Cargo.lock` changes:
Updating indexmap v1.8.0 -> v1.8.2
Updating rayon v1.5.1 -> v1.5.3
Updating rayon-core v1.9.1 -> v1.9.3
Updating rustc-rayon v0.3.2 -> v0.4.0
Updating rustc-rayon-core v0.3.2 -> v0.4.1
Previously whenever a duplicate discriminant was detected for an Enum,
we would print the discriminant bits in the diagnostic without any
casting. This caused us to display incorrect values for negative
discriminants. After this PR we format the discriminant signedness
correctly. Also reworded some of the original error
messages.
proc_macro: don't pass a client-side function pointer through the server.
Before this PR, `proc_macro::bridge::Client<F>` contained both:
* the C ABI entry-point `run`, that the server can call to start the client
* some "payload" `f: F` passed to that entry-point
* in practice, this was always a (client-side Rust ABI) `fn` pointer to the actual function the proc macro author wrote, i.e. `#[proc_macro] fn foo(input: TokenStream) -> TokenStream`
In other words, the client was passing one of its (Rust) `fn` pointers to the server, which was passing it back to the client, for the client to call (see later below for why that was ever needed).
I was inspired by `@nnethercote's` attempt to remove the `get_handle_counters` field from `Client` (see https://github.com/rust-lang/rust/pull/97004#issuecomment-1139273301), which combined with removing the `f` ("payload") field, could theoretically allow for a `#[repr(transparent)]` `Client` that mostly just newtypes the C ABI entry-point `fn` pointer <sub>(and in the context of e.g. wasm isolation, that's *all* you want, since you can reason about it from outside the wasm VM, as just a 32-bit "function table index", that you can pass to the wasm VM to call that function)</sub>.
<hr/>
So this PR removes that "payload". But it's not a simple refactor: the reason the field existed in the first place is because monomorphizing over a function type doesn't let you call the function without having a value of that type, because function types don't implement anything like `Default`, i.e.:
```rust
extern "C" fn ffi_wrapper<A, R, F: Fn(A) -> R>(arg: A) -> R {
let f: F = ???; // no way to get a value of `F`
f(arg)
}
```
That could be solved with something like this, if it was allowed:
```rust
extern "C" fn ffi_wrapper<
A, R,
F: Fn(A) -> R,
const f: F // not allowed because the type is a generic param
>(arg: A) -> R {
f(arg)
}
```
Instead, this PR contains a workaround in `proc_macro::bridge::selfless_reify` (see its module-level comment for more details) that can provide something similar to the `ffi_wrapper` example above, but limited to `F` being `Copy` and ZST (and requiring an `F` value to prove the caller actually can create values of `F` and it's not uninhabited or some other unsound situation).
<hr/>
Hopefully this time we don't have a performance regression, and this has a chance to land.
cc `@mystor` `@bjorn3`
Try to cache region_scope_tree as a query
This PR will attempt to restore `region_scope_tree` as a query so that caching works again. It seems that `region_scope_tree` could be re-computed for nested items after all, which could explain the performance regression introduced by #95563.
cc `@Mark-Simulacrum` `@pnkfelix` I will try to trigger a perf run here.
Split dead store elimination off dest prop
This splits off a part of #96451 . I've added this in as its own pass for now, so that it actually runs, can be tested, etc. In the dest prop PR, I'll stop invoking this as its own pass, so that it doesn't get invoked twice.
r? `@tmiasko`
macros: introduce `fluent_messages` macro
Adds a new `fluent_messages` macro which performs compile-time validation of the compiler's Fluent resources (i.e. that the resources parse and don't multiply define the same messages) and generates constants that make using those messages in diagnostics more ergonomic.
For example, given the following invocation of the macro..
```rust
fluent_messages! {
typeck => "./typeck.ftl",
}
```
..where `typeck.ftl` has the following contents..
```fluent
typeck-field-multiply-specified-in-initializer =
field `{$ident}` specified more than once
.label = used more than once
.label-previous-use = first use of `{$ident}`
```
...then the macro parse the Fluent resource, emitting a diagnostic if it fails to do so...
```text
error: could not parse Fluent resource
--> $DIR/test.rs:35:28
|
LL | missing_message => "./missing-message.ftl",
| ^^^^^^^^^^^^^^^^^^^^^^^
|
= help: see additional errors emitted
error: expected a message field for "missing-message"
--> ./missing-message.ftl:1:1
|
1 | missing-message =
| ^^^^^^^^^^^^^^^^^^
|
```
...or generating the following code if it succeeds:
```rust
pub static DEFAULT_LOCALE_RESOURCES: &'static [&'static str] = &[
include_str!("./typeck.ftl"),
];
mod fluent_generated {
mod typeck {
pub const field_multiply_specified_in_initializer: DiagnosticMessage =
DiagnosticMessage::fluent("typeck-field-multiply-specified-in-initializer");
pub const field_multiply_specified_in_initializer_label_previous_use: DiagnosticMessage =
DiagnosticMessage::fluent_attr(
"typeck-field-multiply-specified-in-initializer",
"previous-use-label"
);
}
}
```
When emitting a diagnostic, the generated constants can be used as follows:
```rust
let mut err = sess.struct_span_err(
span,
fluent::typeck::field_multiply_specified_in_initializer
);
err.span_label(
span,
fluent::typeck::field_multiply_specified_in_initializer_label
);
err.span_label(
previous_use_span,
fluent::typeck::field_multiply_specified_in_initializer_label_previous_use
);
err.emit();
```
I'd like to reduce the verbosity of referring to labels/notes/helps with this scheme (though it wasn't much better before), but I'll leave that for a follow-up.
r? `@oli-obk`
cc `@pvdrz` `@compiler-errors`
Add suggestion for relaxing static lifetime bounds on dyn trait impls in NLL
This PR introduces suggestions for relaxing static lifetime bounds on impls of dyn trait items for NLL similar to what is already available in lexical region diagnostics.
Fixes https://github.com/rust-lang/rust/issues/95701
r? `@estebank`
Update jemalloc to v5.3
Now that `jemalloc` version 5.3 has been released, this PR updates `tikv-jemalloc-sys` to the corresponding release.
The crates.io publishing issue seems to have been resolved for the `jemalloc-sys` package, and version 5.3.0 is now also available under the historical name (and should become the preferred crate to be used). Therefore, this PR also switches back to using `jemalloc-sys` instead of `tikv-jemalloc-sys`.
It looks like the last time had left some remaining cfg's -- which made me think
that the stage0 bump was actually successful. This brings us to a released 1.62
beta though.
Move various checks to typeck so them failing causes the typeck result to get tainted
Fixes#69487fixes#79047
cc `@RalfJung` this gets rid of the `Transmute` invalid program error variant
libcore: Add `iter::from_generator` which is like `iter::from_fn`, but for coroutines instead of functions
An equally useful little helper.
I didn't follow any of the async-wg work, so I don't know why something like this wasn't added before.
omit `record_accesses` function when collecting `MonoItem`s
This PR fixes the FIXME in the impl of `record_accesses` function.
[Edit] We can call `instantiation_mode` when push the `MonoItem` into `neighbors`. This avoids extra local variables `accesses: SmallVec<[_; 128]>`
`imported_source_files` adjusts lots of file positions, and then calls
`new_imported_source_file`, which then adjust them all again. This
commit combines the two adjustments into one, for a small perf win.
- The logic is now unified for all targets (wasm targets should also be supported now)
- Additional "symlink" files like `ld64` are eliminated
- lld-wrapper is used for propagating the correct lld flavor
- Cleanup "unwrap or exit" logic in lld-wrapper
Output correct type responsible for structural match violation
Previously we included the outermost type that caused a structural match violation in the error message and stated that that type must be annotated with `#[derive(Eq, PartialEq)]` even if it already had that annotation. This PR outputs the correct type in the error message.
Fixes https://github.com/rust-lang/rust/issues/97278
Do writeback of Closure params before visiting the parent expression
This means that given the expression:
```
let x = |a: Vec<_>| {};
```
We will visit the HIR node for `a` before `x`, and report the ambiguity on the former instead of the latter. This also moves writeback for struct field ids and const blocks before, but the ordering of this and walking the expr doesn't seem to matter.
This was relying on the presence of a bitcast to avoid using the
constant global initializer for a load using a different type.
With opaque pointers, we need to check this explicitly.
Minor improvement on else-no-if diagnostic
Don't suggest wrapping in block since it's highly likely to be a missing `if` after `else`. Also rework message a bit (open to further suggestions).
cc: https://github.com/rust-lang/rust/pull/97298#discussion_r880933431
r? `@estebank`
RFC3239: Implement `cfg(target)` - Part 2
This pull-request implements the compact `cfg(target(..))` part of [RFC 3239](https://github.com/rust-lang/rust/issues/96901).
I recommend reviewing this PR on a per commit basics, because of some moving parts.
cc `@GuillaumeGomez`
r? `@petrochenkov`
Modify MIR building to drop repeat expressions with length zero
Closes#74836 .
Previously, when a user wrote `[foo; 0]` we used to simply leak `foo`. The goal is to fix that. This PR changes MIR building to make `[foo; 0]` equivalent to `{ drop(foo); [] }` in all cases. Of course, this is a breaking change (see below). A crater run did not indicate any regressions though, and given that the previous behavior was almost definitely not what any user wanted, it seems unlikely that anyone was relying on this.
Note that const generics are in general unaffected by this. Inserting the extra `drop` is only meaningful/necessary when `foo` is of a non-`Copy` type, and array repeat expressions with const generic repetition count must always be `Copy`.
Besides the obvious change to behavior associated with the additional drop, there are three categories of examples where this also changes observable behavior. In all of these cases, the new behavior is consistent with what you would get by replacing `[foo; 0]` with `{ drop(foo); [] }`. As such, none of these give the user new powers to express more things.
**No longer allowed in const (breaking)**:
```rust
const _: [String; 0] = [String::new(); 0];
```
This compiles on stable today. Because we now introduce the drop of `String`, this no longer compiles as `String` may not be dropped in a const context.
**Reduced dataflow (non-breaking)**:
```rust
let mut x: i32 = 0;
let r = &x;
let a = [r; 0];
x = 5;
let _b = a;
```
Borrowck rejects this code on stable because it believes there is dataflow between `a` and `r`, and so the lifetime of `r` has to extend to the last statement. This change removes the dataflow and the above code is allowed to compile.
**More const promotion (non-breaking)**:
```rust
let _v: &'static [String; 0] = &[String::new(); 0];
```
This does not compile today because `String` having drop glue keeps it from being const promoted (despite that drop glue never being executed). After this change, this is allowed to compile.
### Alternatives
A previous attempt at this tried to reduce breakage by various tricks. This is still a possibility, but given that crater showed no regressions it seems unclear why we would want to introduce this complexity.
Disallowing `[foo; 0]` completely is also an option, but obviously this is more of a breaking change. I do not know how often this is actually used though.
r? `@oli-obk`
add a deep fast_reject routine
continues the work on #97136.
r? `@nnethercote`
Actually agree with you on the match structure 😆 let's see how that impacted perf 😅
Rollup of 5 pull requests
Successful merges:
- #93604 (Make llvm-libunwind a per-target option)
- #97026 (Change orderings of `Debug` for the Atomic types to `Relaxed`.)
- #97105 (Add tests for lint on type dependent on consts)
- #97323 (Introduce stricter checks for might_permit_raw_init under a debug flag )
- #97379 (Add aliases for `current_dir`)
Failed merges:
r? `@ghost`
`@rustbot` modify labels: rollup
`match_impl` has two call sites. For one of them (within `rematch_impl`)
the fast reject test isn't necessary, because any rejection would
represent a compiler bug.
This commit moves the fast reject test to the other `match_impl` call
site, in `assemble_candidates_from_impls`. This lets us move the fast
reject test outside the `probe` call in that function. This avoids the
taking of useless snapshots when the fast reject test succeeds, which
gives a performance win when compiling the `bitmaps` and `nalgebra`
crates.
Co-authored-by: name <n.nethercote@gmail.com>
Introduce stricter checks for might_permit_raw_init under a debug flag
This is intended to be a version of the strict checks tried out in #79296, but also checking number validity (under the assumption that `let _ = std::mem::uninitialized::<u32>()` is UB, which seems to be what https://github.com/rust-lang/unsafe-code-guidelines/issues/71 is leaning towards.)
Make `Lazy*<T>` types in `rustc_metadata` not care about lifetimes until decode
This allows us to remove the `'tcx` lifetime from `CrateRoot`. This is necessary because of #97287, which makes the `'tcx` lifetime on `Ty` invariant instead of covariant, so [this hack](0a437b2ca0/compiler/rustc_metadata/src/rmeta/decoder.rs (L89-92)) no longer holds under that PR.
Introduces a trait called `ParameterizedOverTcx` which has a generic associated type that allows a type to be parameterized over that lifetime. This means we can decode, for example, `Lazy<Ty<'static>>` into any `Ty<'tcx>` depending on the `TyCtxt<'tcx>` we pass into the decode function.
Make weird name lints trigger behind cfg_attr
The weird name lints (`unknown_lints`, `renamed_and_removed_lints`), the lints that lint the linting, were previously not firing for lint level declarations behind `cfg_attr`, as they were only running before expansion.
Now, this will give a `unknown_lints` warning:
```Rust
#[cfg_attr(all(), allow(this_lint_does_not_exist))]
fn foo() {}
```
Lint level declarations behind a `cfg_attr` whose condition is not applying are still ignored. So this still won't give a warning:
```Rust
#[cfg_attr(any(), allow(this_lint_does_not_exist))]
fn foo() {}
```
Furthermore, this PR also makes the weird name lints respect level delcarations for *them* that were hidden by `cfg_attr`, making them consistent to other lints. So this will now not issue a warning:
```Rust
#[cfg_attr(all(), allow(unknown_lints))]
mod foo {
#[allow(does_not_exist)]
fn foo() {
}
}
```
Fixes#97094
Ensure all error checking for `#[debugger_visualizer]` is done up front and not when the `debugger_visualizer` query is run.
Clean up potential ODR violations when embedding pretty printers into the `__rustc_debug_gdb_scripts_section__` section.
Respond to PR comments and update documentation.
Rollup of 4 pull requests
Successful merges:
- #97288 (Lifetime variance fixes for rustdoc)
- #97298 (Parse expression after `else` as a condition if followed by `{`)
- #97308 (Stabilize `cell_filter_map`)
- #97321 (explain how to turn integers into fn ptrs)
Failed merges:
r? `@ghost`
`@rustbot` modify labels: rollup
Use new typed Fluent identifiers for the "missing type parameters"
diagnostic in the typeck crate which was manually creating
`DiagnosticMessage`s previously.
Signed-off-by: David Wood <david.wood@huawei.com>
Adds a new `fluent_messages` macro which performs compile-time
validation of the compiler's Fluent resources (i.e. that the resources
parse and don't multiply define the same messages) and generates
constants that make using those messages in diagnostics more ergonomic.
For example, given the following invocation of the macro..
```ignore (rust)
fluent_messages! {
typeck => "./typeck.ftl",
}
```
..where `typeck.ftl` has the following contents..
```fluent
typeck-field-multiply-specified-in-initializer =
field `{$ident}` specified more than once
.label = used more than once
.label-previous-use = first use of `{$ident}`
```
...then the macro parse the Fluent resource, emitting a diagnostic if it
fails to do so, and will generate the following code:
```ignore (rust)
pub static DEFAULT_LOCALE_RESOURCES: &'static [&'static str] = &[
include_str!("./typeck.ftl"),
];
mod fluent_generated {
mod typeck {
pub const field_multiply_specified_in_initializer: DiagnosticMessage =
DiagnosticMessage::fluent("typeck-field-multiply-specified-in-initializer");
pub const field_multiply_specified_in_initializer_label_previous_use: DiagnosticMessage =
DiagnosticMessage::fluent_attr(
"typeck-field-multiply-specified-in-initializer",
"previous-use-label"
);
}
}
```
When emitting a diagnostic, the generated constants can be used as
follows:
```ignore (rust)
let mut err = sess.struct_span_err(
span,
fluent::typeck::field_multiply_specified_in_initializer
);
err.span_default_label(span);
err.span_label(
previous_use_span,
fluent::typeck::field_multiply_specified_in_initializer_label_previous_use
);
err.emit();
```
Signed-off-by: David Wood <david.wood@huawei.com>
With `ignore (rust)` rather than `ignore (pseudo-Rust)` my editor
highlights the code in the block, which is nicer.
Signed-off-by: David Wood <david.wood@huawei.com>
Previously, we were emitting weird name lints (for renamed or unknown lints)
before expansion, most importantly before cfg expansion.
This meant that the weird name lints would not fire
for lint attributes hidden inside cfg_attr. The same applied
for lint level specifications of those lints.
By moving the lints for the lint names to the post-expansion
phase, these issues are resolved.
Parse expression after `else` as a condition if followed by `{`
Fixes#49361.
Two things:
1. This wording needs help. I can never find a natural/intuitive phrasing when I write diagnostics 😅
2. Do we even want to show the "wrap in braces" case? I would assume most of the time the "add an `if`" case is the right one.
Lifetime variance fixes for rustdoc
#97287 migrates rustc to a `Ty` type that is invariant over its lifetime `'tcx`, so I need to fix a bunch of places that assume that `Ty<'a>` and `Ty<'b>` can be unified by shortening both to some common lifetime.
This is doable, since everything is already `'tcx`, so all this PR does is be a bit more explicit that elided lifetimes are actually `'tcx`.
Split out from #97287 so the rustdoc team can review independently.
Split out the various responsibilities of `rustc_metadata::Lazy`
`Lazy<T>` actually acts like three different types -- a pointer in the crate metadata to a single value, a pointer to a list/array of values, and an indexable pointer of a list of values (a table).
We currently overload `Lazy<T>` to work differently than `Lazy<[T]>` and the same for `Lazy<Table<I, T>>`. All is well with some helper adapter traits such as [`LazyQueryDecodable`](https://doc.rust-lang.org/nightly/nightly-rustc/rustc_metadata/rmeta/decoder/trait.LazyQueryDecodable.html) and [`EncodeContentsForLazy`](https://doc.rust-lang.org/nightly/nightly-rustc/rustc_metadata/rmeta/encoder/trait.EncodeContentsForLazy.html).
Well, changes in #97287 that make `Lazy` work with the now invariant lifetime `'tcx` make these adapters fall apart because of coherence reasons. So we split out these three types and rework some of the helper traits so it's both 1. more clear to understand, and 2. compatible with the changes later in that PR.
Split out from #97287 so it can be reviewed separately, since this PR stands on its own.
Refactor call terminator to always include destination place
In #71117 people seemed to agree that call terminators should always have a destination place, even if the call was guaranteed to diverge. This implements that. Unsurprisingly, the diff touches a lot of code, but thankfully I had to do almost nothing interesting. The only interesting thing came up in const prop, where the stack frame having no return place was also used to indicate that the layout could not be computed (or similar). I replaced this with a ZST allocation, which should continue to do the right things.
cc `@RalfJung` `@eddyb` who were involved in the original conversation
r? rust-lang/mir-opt
Move a bunch of branches together into one if block, for easier reading.
Resolve comments
Attempt to make some branches unreachable [tmp]
Revert unreachable branches
When constructing a MIR from a THIR field expression, introduce an
additional downcast projection before accessing a field of an enum.
When rebasing a place builder on top of a captured place, account for
the fact that a single HIR enum field projection corresponds to two MIR
projection elements: a downcast element and a field element.
Lifetime variance fixes for rustc
#97287 migrates rustc to a `Ty` type that is invariant over its lifetime `'tcx`, so I need to fix a bunch of places that assume that `Ty<'a>` and `Ty<'b>` can be unified by shortening both to some common lifetime.
This is doable, since many lifetimes are already `'tcx`, so all this PR does is be a bit more explicit that elided lifetimes are actually `'tcx`.
Split out from #97287 so the compiler team can review independently.
rustdoc: shrink GenericArgs/PathSegment with boxed slices
This PR also contains a few cleanup bits and pieces, but one of them is a broken intra-doc link, and the other is removing an unused Hash impl. The last commit is the one that matters.
Remove box syntax from rustc_mir_dataflow and rustc_mir_transform
Continuation of #87781, inspired by #97239. The usages that this PR removes have not appeared from nothing, instead the usage in `rustc_mir_dataflow` and `rustc_mir_transform` was from #80522 which split up `rustc_mir`, and which was filed before I filed #87781, so it was using the state from before my PR. But it was merged after my PR was merged, so the `box_syntax` uses were able to survive here. Outside of this introduction due to the code being outside of the master branch at the point of merging of my PR, there was only one other introduction of box syntax, in #95159. That box syntax was removed again though in #95555. Outside of that, `box_syntax` has not made its reoccurrance in compiler crates.
rustc_parse: Move AST -> TokenStream conversion logic to rustc_ast
In the past falling back to reparsing pretty-printed strings was common, so some of this logic had to live in `rustc_parse`, but now the reparsing fallback is only used in two corner cases so we can move this logic to `rustc_ast` which makes many things simpler.
It also helps to fix `MacArgs::inner_tokens` for `MacArgs::Eq` with non-literal expressions, which is done in the second commit.
r? `@nnethercote`
Move the extended lifetime resolution into typeck context
Related to #15023
This PR is based on the [idea](https://github.com/rust-lang/rust/issues/15023#issuecomment-1070931433) of #15023 by `@nikomatsakis.`
This PR specifically proposes to
- Delay the resolution of scopes of rvalues to a later stage, so that enough type information is available to refine those scopes based on relationships of lifetimes.
- Highlight relevant parts that would help future reviews on the next installments of works to fully implement a solution to RFC 66.
Implement proper stability check for const impl Trait, fall back to unstable const when undeclared
Continuation of #93960
`@jhpratt` it looks to me like the test was simply not testing for the failure you were looking for? Your checks actually do the right thing for const traits?
correctly deal with user type ascriptions in pat
supersedes #93856
`thir::PatKind::AscribeUserType` previously resulted in `CanonicalUserTypeAnnotations` where the inferred type already had a subtyping relation according to `variance` to the `user_ty`.
The bug can pretty much be summarized as follows:
- during mir building
- `user_ty -> inferred_ty`: considers variance
- `StatementKind::AscribeUserType`: `inferred_ty` is the type of the place, so no variance needed
- during mir borrowck
- `user_ty -> inferred_ty`: does not consider variance
- `StatementKind::AscribeUserType`: applies variance
This mostly worked fine. The lifetimes in `inferred_ty` were only bound by its relation to `user_ty` and to the `place` of `StatementKind::AscribeUserType`, so it doesn't matter where exactly the subtyping happens.
It does however matter when having higher ranked subtying. At this point the place where the subtyping happens is forced, causing this mismatch between building and borrowck to result in unintended errors.
cc #96514 which is pretty much the same issue
r? `@nikomatsakis`
Remove `crate` visibility modifier
FCP to remove this syntax is just about complete in #53120. Once it completes, this should be merged ASAP to avoid merge conflicts.
The first two commits remove usage of the feature in this repository, while the last removes the feature itself.
Drop Tracking: Implement `fake_read` callback
This PR updates drop tracking's use of `ExprUseVisitor` so that we treat `fake_read` events as borrows. Without doing this, we were not handling match expressions correctly, which showed up as a breakage in the `addassign-yield.rs` test. We did not previously notice this because we still had rather large temporary scopes that we held borrows for, which changed in #94309.
This PR also includes a variant of the `addassign-yield.rs` test case to make sure we continue to have correct behavior here with drop tracking.
r? `@nikomatsakis`
Cache more queries on disk
One of the principles of incremental compilation is to allow saving results on disk to avoid recomputing them.
This PR investigates persisting a lot of queries whose result are to be saved into metadata.
Some of the queries are cheap reads from HIR, but we may also want to get rid of these reads for incremental lowering.
Do not emit the lint `unused_attributes` for *inherent* `#[doc(hidden)]` associated items
Fixes#97205 (embarrassing oversight from #96008).
`@rustbot` label A-lint
Rollup of 6 pull requests
Successful merges:
- #96565 (rustdoc: show implementations on `#[fundamental]` wrappers)
- #97179 (Add new lint to enforce whitespace after keywords)
- #97185 (interpret/validity: separately control checking numbers for being init and non-ptr)
- #97188 (Remove unneeded null pointer asserts in ptr2int casts)
- #97189 (Update .mailmap)
- #97192 (Say "last" instead of "rightmost" in the documentation for `std::str:rfind`)
Failed merges:
r? `@ghost`
`@rustbot` modify labels: rollup
Remove unneeded null pointer asserts in ptr2int casts
This removes an assert that a pointer with address 0 has no provenance. This change is needed to support permissive provenance work in Miri, and seems justified by `ptr.with_addr(0)` working and a discussion on Zulip regarding LLVM semantics.
r? `@RalfJung`
interpret/validity: separately control checking numbers for being init and non-ptr
This lets Miri control this in a more fine-grained way.
r? `@oli-obk`
generator_interior: Count match pattern bindings as borrowed for the whole guard expression
The test case `yielding-in-match-guard.rs` was failing with `-Zdrop-tracking` enabled. The reason is that the copy of a local (`y`) was not counted as a borrow in typeck, while MIR did consider this as borrowed.
The correct thing to do here is to count pattern bindings are borrowed for the whole guard. Instead, what we were doing is to record the type at the use site of the variable and check if the variable comes from a borrowed pattern. Due to the fix for #57017, we were considering too small of a scope for this variable, which meant it was not counted as borrowed.
Because we now unconditionally record the borrow, rather than only for bindings that are used, this PR is also able to remove a lot of the logic around match bindings that was there before.
r? `@nikomatsakis`
