This replaces the drop_in_place reference with null in vtables. On
librustc_driver.so, this drops about ~17k dynamic relocations from the
output, since many vtables can now be placed in read-only memory, rather
than having a relocated pointer included.
This makes a tradeoff by adding a null check at vtable call sites.
That's hard to avoid without changing the vtable format (e.g., to use a
pc-relative relocation instead of an absolute address, and avoid the
dynamic relocation that way). But it seems likely that the check is
cheap at runtime.
drop region constraints for ambiguous goals
See the comment in `compute_external_query_constraints`. While the underlying issue is preexisting, this fixes a bug introduced by #125343.
It slightly weakens the leak chec, even if we didn't have any test which was affected. I want to write such a test before merging this PR.
r? `@compiler-errors`
Uplift `EarlyBinder` into `rustc_type_ir`
We also need to give `EarlyBinder` a `'tcx` param, so that we can carry the `Interner` in the `EarlyBinder` too. This is necessary because otherwise we have an unconstrained `I: Interner` parameter in many of the `EarlyBinder`'s inherent impls.
I also generally think that this is desirable to have, in case we later want to track some state in the `EarlyBinder`.
r? lcnr
cleanup dependence of `ExtCtxt` in transcribe when macro expansion
part of #125356
We can remove `transcribe`’s dependence on `ExtCtxt` to facilitate subsequent work (such as moving macro expansion into the incremental compilation system)
r? ```@petrochenkov```
Thanks for the reviewing!
interpret: get rid of 'mir lifetime
I realized our MIR bodies are actually at lifetime `'tcx`, so we don't need to carry around this other lifetime everywhere.
r? `@oli-obk`
[perf] Delay the construction of early lint diag structs
Attacks some of the perf regressions from https://github.com/rust-lang/rust/pull/124417#issuecomment-2123700666.
See individual commits for details. The first three commits are not strictly necessary.
However, the 2nd one (06bc4fc671, *Remove `LintDiagnostic::msg`*) makes the main change way nicer to implement.
It's also pretty sweet on its own if I may say so myself.
Remove `DefId` from `EarlyParamRegion`
Currently we represent usages of `Region` parameters via the `ReEarlyParam` or `ReLateParam` variants. The `ReEarlyParam` is effectively equivalent to `TyKind::Param` and `ConstKind::Param` (i.e. it stores a `Symbol` and a `u32` index) however it also stores a `DefId` for the definition of the lifetime parameter.
This was used in roughly two places:
- Borrowck diagnostics instead of threading the appropriate `body_id` down to relevant locations. Interestingly there were already some places that had to pass down a `DefId` manually.
- Some opaque type checking logic was using the `DefId` field to track captured lifetimes
I've split this PR up into a commit for generate rote changes to diagnostics code to pass around a `DefId` manually everywhere, and another commit for the opaque type related changes which likely require more careful review as they might change the semantics of lints/errors.
Instead of manually passing the `DefId` around everywhere I previously tried to bundle it in with `TypeErrCtxt` but ran into issues with some call sites of `infcx.err_ctxt` being unable to provide a `DefId`, particularly places involved with trait solving and normalization. It might be worth investigating adding some new wrapper type to pass this around everywhere but I think this might be acceptable for now.
This pr also has the effect of reducing the size of `EarlyParamRegion` from 16 bytes -> 8 bytes. I wouldn't expect this to have any direct performance improvement however, other variants of `RegionKind` over `8` bytes are all because they contain a `BoundRegionKind` which is, as far as I know, mostly there for diagnostics. If we're ever able to remove this it would shrink the `RegionKind` type from `24` bytes to `12` (and with clever bit packing we might be able to get it to `8` bytes). I am curious what the performance impact would be of removing interning of `Region`'s if we ever manage to shrink `RegionKind` that much.
Sidenote: by removing the `DefId` the `Debug` output for `Region` has gotten significantly nicer. As an example see this opaque type debug print before vs after this PR:
`Opaque(DefId(0:13 ~ impl_trait_captures[aeb9]::foo::{opaque#0}), [DefId(0:9 ~ impl_trait_captures[aeb9]::foo::'a)_'a/#0, T, DefId(0:9 ~ impl_trait_captures[aeb9]::foo::'a)_'a/#0])`
`Opaque(DefId(0:13 ~ impl_trait_captures[aeb9]::foo::{opaque#0}), ['a/#0, T, 'a/#0])`
r? `@compiler-errors` (I would like someone who understands the opaque type setup to atleast review the type system commit, but the rest is likely reviewable by anyone)
Don't skip out of inner const when looking for body for suggestion
Self-explanatory title, I'll point out the important logic in an inline comment.
Fixes#125370
Don't continue probing for method if in suggestion and autoderef hits ambiguity
The title is somewhat self-explanatory. When we hit ambiguity in method autoderef steps, we previously would continue to probe for methods if we were giving a suggestion. This seems useless, and causes an ICE when we are not able to unify the receiver later on in confirmation.
Fixes#125432
Support C23's Variadics Without a Named Parameter
Fixes#123773
This PR removes the static check that disallowed extern functions
with ellipsis (varargs) as the only parameter since this is now
valid in C23.
This will not break any existing code as mentioned in the proposal
document: https://www.open-std.org/jtc1/sc22/wg14/www/docs/n2975.pdf.
Also, adds a doc comment for `check_decl_cvariadic_pos()` and
fixes the name of the function (`varadic` -> `variadic`).
Turn remaining non-structural-const-in-pattern lints into hard errors
This completes the implementation of https://github.com/rust-lang/rust/issues/120362 by turning our remaining future-compat lints into hard errors: indirect_structural_match and pointer_structural_match.
They have been future-compat lints for a while (indirect_structural_match for many years, pointer_structural_match since Rust 1.75 (released Dec 28, 2023)), and have shown up in dependency breakage reports since Rust 1.78 (just released on May 2, 2024). I don't expect a lot of code will still depend on them, but we will of course do a crater run.
A lot of cleanup is now possible in const_to_pat, but that is deferred to a later PR.
Fixes https://github.com/rust-lang/rust/issues/70861
Warn (or error) when `Self` ctor from outer item is referenced in inner nested item
This implements a warning `SELF_CONSTRUCTOR_FROM_OUTER_ITEM` when a self constructor from an outer impl is referenced in an inner nested item. This is a proper fix mentioned https://github.com/rust-lang/rust/pull/117246#discussion_r1374648388.
This warning is additionally bumped to a hard error when the self type references generic parameters, since it's almost always going to ICE, and is basically *never* correct to do.
This also reverts part of https://github.com/rust-lang/rust/pull/117246, since I believe this is the proper fix and we shouldn't need the helper functions (`opt_param_at`/`opt_type_param`) any longer, since they shouldn't really ever be used in cases where we don't have this problem.
Resolve anon const's parent predicates to direct parent instead of opaque's parent
When an anon const is inside of an opaque, #99801 added a hack to resolve the anon const's parent predicates *not* to the opaque's predicates, but to the opaque's *parent's* predicates. This is insufficient when considering nested opaques.
This means that the `predicates_of` an anon const might reference duplicated lifetimes (installed by `compute_bidirectional_outlives_predicates`) when computing known outlives in MIR borrowck, leading to these ICEs:
Fixes#121574Fixes#118403
~~Instead, we should be using the `OpaqueTypeOrigin` to acquire the owner item (fn/type alias/etc) of the opaque, whose predicates we're fine to mention.~~
~~I think it's a bit sketchy that we're doing this at all, tbh; I think it *should* be fine for the anon const to inherit the predicates of the opaque it's located inside. However, that would also mean that we need to make sure the `generics_of` that anon const line up in the same way.~~
~~None of this is important to solve right now; I just want to fix these ICEs so we can land #125468, which accidentally fixes these issues in a different and unrelated way.~~
edit: We don't need this special case anyways because we install the right parent item in `generics_of` anyways:
213ad10c8f/compiler/rustc_hir_analysis/src/collect/generics_of.rs (L150)
r? `@BoxyUwU`
compiler: validate.rs belongs next to what it validates
It's hard to find code that is deeply nested and far away from its callsites, so let's move `rustc_const_eval::transform::validate` into `rustc_mir_transform`, where all of its callers are. As `rustc_mir_transform` already depends on `rustc_const_eval`, the added visible dependency edge doesn't mean the dependency tree got any worse.
This also lets us unnest the `check_consts` module.
I did look into moving everything inside `rustc_const_eval::transform` into `rustc_mir_transform`. It turned out to be a much more complex operation, with more concerns and real edges into the `const_eval` crate, whereas this was both faster and more obvious.
Only suppress binop error in favor of semicolon suggestion if we're in an assignment statement
Similar to #123722, we are currently too aggressive when delaying a binop error with the expectation that we'll emit another error elsewhere. This adjusts that heuristic to be more accurate, at the cost of some possibly poorer suggestions.
Fixes#125458
Run rustfmt on files that need it.
Somehow these files aren't properly formatted. By default `x fmt` and `x tidy` only check files that have changed against master, so if an ill-formatted file somehow slips in it can stay that way as long as it doesn't get modified(?)
I found these when I ran `x fmt` explicitly on every `.rs` file in the repo, while working on
https://github.com/rust-lang/compiler-team/issues/750.
Validate the special layout restriction on `DynMetadata`
If you look at <https://stdrs.dev/nightly/x86_64-unknown-linux-gnu/std/ptr/struct.DynMetadata.html>, you'd think that `DynMetadata` is a struct with fields.
But it's actually not, because the lang item is special-cased in rustc_middle layout:
7601adcc76/compiler/rustc_middle/src/ty/layout.rs (L861-L864)
That explains the very confusing codegen ICEs I was getting in https://github.com/rust-lang/rust/pull/124251#issuecomment-2128543265
> Tried to extract_field 0 from primitive OperandRef(Immediate((ptr: %5 = load ptr, ptr %4, align 8, !nonnull !3, !align !5, !noundef !3)) @ TyAndLayout { ty: DynMetadata<dyn Callsite>, layout: Layout { size: Size(8 bytes), align: AbiAndPrefAlign { abi: Align(8 bytes), pref: Align(8 bytes) }, abi: Scalar(Initialized { value: Pointer(AddressSpace(0)), valid_range: 1..=18446744073709551615 }), fields: Primitive, largest_niche: Some(Niche { offset: Size(0 bytes), value: Pointer(AddressSpace(0)), valid_range: 1..=18446744073709551615 }), variants: Single { index: 0 }, max_repr_align: None, unadjusted_abi_align: Align(8 bytes) } })
because there was a `Field` projection despite the layout clearly saying it's [`Primitive`](https://doc.rust-lang.org/nightly/nightly-rustc/rustc_target/abi/enum.FieldsShape.html#variant.Primitive).
Thus this PR updates the MIR validator to check for such a projection, and changes `libcore` to not ever emit any projections into `DynMetadata`, just to transmute the whole thing when it wants a pointer.
Somehow these files aren't properly formatted. By default `x fmt` and `x
tidy` only check files that have changed against master, so if an
ill-formatted file somehow slips in it can stay that way as long as it
doesn't get modified(?)
I found these when I ran `x fmt` explicitly on every `.rs` file in the
repo, while working on
https://github.com/rust-lang/compiler-team/issues/750.
Rollup of 6 pull requests
Successful merges:
- #125263 (rust-lld: fallback to rustc's sysroot if there's no path to the linker in the target sysroot)
- #125345 (rustc_codegen_llvm: add support for writing summary bitcode)
- #125362 (Actually use TAIT instead of emulating it)
- #125412 (Don't suggest adding the unexpected cfgs to the build-script it-self)
- #125445 (Migrate `run-make/rustdoc-with-short-out-dir-option` to `rmake.rs`)
- #125452 (Cleanup check-cfg handling in core and std)
r? `@ghost`
`@rustbot` modify labels: rollup
Don't suggest adding the unexpected cfgs to the build-script it-self
This PR adds a check to avoid suggesting to add the unexpected cfgs inside the build-script when building the build-script it-self, as it won't have any effect, since build-scripts applies to their descended target.
Fixes#125368
rustc_codegen_llvm: add support for writing summary bitcode
Typical uses of ThinLTO don't have any use for this as a standalone file, but distributed ThinLTO uses this to make the linker phase more efficient. With clang you'd do something like `clang -flto=thin -fthin-link-bitcode=foo.indexing.o -c foo.c` and then get both foo.o (full of bitcode) and foo.indexing.o (just the summary or index part of the bitcode). That's then usable by a two-stage linking process that's more friendly to distributed build systems like bazel, which is why I'm working on this area.
I talked some to `@teresajohnson` about naming in this area, as things seem to be a little confused between various blog posts and build systems. "bitcode index" and "bitcode summary" tend to be a little too ambiguous, and she tends to use "thin link bitcode" and "minimized bitcode" (which matches the descriptions in LLVM). Since the clang option is thin-link-bitcode, I went with that to try and not add a new spelling in the world.
Per `@dtolnay,` you can work around the lack of this by using `lld --thinlto-index-only` to do the indexing on regular .o files of bitcode, but that is a bit wasteful on actions when we already have all the information in rustc and could just write out the matching minimized bitcode. I didn't test that at all in our infrastructure, because by the time I learned that I already had this patch largely written.
rust-lld: fallback to rustc's sysroot if there's no path to the linker in the target sysroot
As seen in #125246, some sysroots don't expect to contain `rust-lld` and want to keep it that way, so we fallback to the default rustc sysroot if there is no path to the linker in any of the sysroot tools search paths. This is how we locate codegen-backends' dylibs already.
People also have requested an error if none of these search paths contain the self-contained linker directory, so there's also an error in that case.
r? `@petrochenkov` cc `@ehuss` `@RalfJung`
I'm not sure where we check for `rust-lld`'s existence on the targets where we use it by default, and if we just ignore it when missing or emit a warning (as I assume we don't emit an error), so I just checked for the existence of `gcc-ld`, where `cc` will look for the lld-wrapper binaries.
<sub>*Feel free to point out better ways to do this, it's the middle of the night here.*</sub>
Fixes#125246
Remove more `#[macro_use] extern crate tracing`
Because explicit importing of macros via use items is nicer (more standard and readable) than implicit importing via `#[macro_use]`. Continuing the work from #124511 and #124914.
r? `@jackh726`
If we don't do this, some versions of LLVM (at least 17, experimentally)
will double-emit some error messages, which is how I noticed this. Given
that it seems to be costing some extra work, let's only request the
summary bitcode production if we'll actually bother writing it down,
otherwise skip it.
Improve the doc of query associated_item
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This query also maps from a impl item to the impl item "descriptor". So it's a bit confused, I skipped it cause it doesn't say it contains impl items.
```rust
fn associated_item(tcx: TyCtxt<'_>, def_id: LocalDefId) -> ty::AssocItem {
let id = tcx.local_def_id_to_hir_id(def_id);
let parent_def_id = tcx.hir().get_parent_item(id);
let parent_item = tcx.hir().expect_item(parent_def_id.def_id);
match parent_item.kind {
hir::ItemKind::Impl(impl_) => {
if let Some(impl_item_ref) = impl_.items.iter().find(|i| i.id.owner_id.def_id == def_id)
{
let assoc_item = associated_item_from_impl_item_ref(impl_item_ref);
debug_assert_eq!(assoc_item.def_id.expect_local(), def_id);
return assoc_item;
}
}
hir::ItemKind::Trait(.., trait_item_refs) => {
if let Some(trait_item_ref) =
trait_item_refs.iter().find(|i| i.id.owner_id.def_id == def_id)
{
let assoc_item = associated_item_from_trait_item_ref(trait_item_ref);
debug_assert_eq!(assoc_item.def_id.expect_local(), def_id);
return assoc_item;
}
}
_ => {}
}
span_bug!(
parent_item.span,
"unexpected parent of trait or impl item or item not found: {:?}",
parent_item.kind
)
}
```
We already handle this case this way on the coherence side, and it matches the new solver's behaviour. While there is some breakage around type-alias-impl-trait (see new "type annotations needed" in tests/ui/type-alias-impl-trait/issue-84660-unsoundness.rs), no stable code breaks, and no new stable code is accepted.
Use correct param-env in `MissingCopyImplementations`
We shouldn't assume the param-env is empty for this lint, since although we check the struct has no parameters, there still may be trivial where-clauses.
fixes#125394
Cleanup: Fix up some diagnostics
Several diagnostics contained their error code inside their primary message which is no bueno.
This PR moves them out of the message and turns them into structured error codes.
Also fixes another occurrence of `->` after a selector in a Fluent message which is not correct. I've fixed two other instances of this issue in #104345 (2022) but didn't update all instances as I've noted here: https://github.com/rust-lang/rust/pull/104345#issuecomment-1312705977 (“the future is now!”).
Allow coercing functions whose signature differs in opaque types in their defining scope into a shared function pointer type
r? `@compiler-errors`
This accepts more code on stable. It is now possible to have match arms return a function item `foo` and a different function item `bar` in another, and that will constrain OpaqueTypeInDefiningScope to have the hidden type ConcreteType and make the type of the match arms a function pointer that matches the signature. So the following function will now compile, but on master it errors with a type mismatch on the second match arm
```rust
fn foo<T>(t: T) -> T {
t
}
fn bar<T>(t: T) -> T {
t
}
fn k() -> impl Sized {
fn bind<T, F: FnOnce(T) -> T>(_: T, f: F) -> F {
f
}
let x = match true {
true => {
let f = foo;
bind(k(), f)
}
false => bar::<()>,
};
todo!()
}
```
cc https://github.com/rust-lang/rust/issues/116652
This is very similar to https://github.com/rust-lang/rust/pull/123794, and with the same rationale:
> this is for consistency with `-Znext-solver`. the new solver does not have the concept of "non-defining use of opaque" right now and we would like to ideally keep it that way. Moving to `DefineOpaqueTypes::Yes` in more cases removes subtlety from the type system. Right now we have to be careful when relating `Opaque` with another type as the behavior changes depending on whether we later use the `Opaque` or its hidden type directly (even though they are equal), if that later use is with `DefineOpaqueTypes::No`*
self-contained linker: retry linking without `-fuse-ld=lld` on CCs that don't support it
For the self-contained linker, this PR applies [the strategy](https://github.com/rust-lang/rust/issues/125330#issuecomment-2125119838) of retrying the linking step when the driver doesn't support `-fuse-ld=lld`, but with the option removed. This is the same strategy we already use of retrying when e.g. `-no-pie` is not supported.
Fixes#125330
r? `@petrochenkov`
I have no idea how we could add a test here, much like we don't have one for `-no-pie` or `-static-pie` -- let me know if you have ideas -- but I tested on a CentOS7 image:
```console
[root@d25b38376ede tmp]# ../build/host/stage1/bin/rustc helloworld.rs
WARN rustc_codegen_ssa:🔙:link The linker driver does not support `-fuse-ld=lld`. Retrying without it.
[root@d25b38376ede tmp]# readelf -p .comment helloworld
String dump of section '.comment':
[ 0] GCC: (GNU) 4.8.5 20150623 (Red Hat 4.8.5-44)
[ 2d] rustc version 1.80.0-dev
```
I wasn't able to test with `cross` as the issue describes: I wasn't able to reproduce that behavior locally.
Expand `for_loops_over_fallibles` lint to lint on fallibles behind references.
Extends the scope of the (warn-by-default) lint `for_loops_over_fallibles` from just `for _ in x` where `x: Option<_>/Result<_, _>` to also cover `x: &(mut) Option<_>/Result<_>`
```rs
fn main() {
// Current lints
for _ in Some(42) {}
for _ in Ok::<_, i32>(42) {}
// New lints
for _ in &Some(42) {}
for _ in &mut Some(42) {}
for _ in &Ok::<_, i32>(42) {}
for _ in &mut Ok::<_, i32>(42) {}
// Should not lint
for _ in Some(42).into_iter() {}
for _ in Some(42).iter() {}
for _ in Some(42).iter_mut() {}
for _ in Ok::<_, i32>(42).into_iter() {}
for _ in Ok::<_, i32>(42).iter() {}
for _ in Ok::<_, i32>(42).iter_mut() {}
}
```
<details><summary><code>cargo build</code> diff</summary>
```diff
diff --git a/old.out b/new.out
index 84215aa..ca195a7 100644
--- a/old.out
+++ b/new.out
`@@` -1,33 +1,93 `@@`
warning: for loop over an `Option`. This is more readably written as an `if let` statement
--> src/main.rs:3:14
|
3 | for _ in Some(42) {}
| ^^^^^^^^
|
= note: `#[warn(for_loops_over_fallibles)]` on by default
help: to check pattern in a loop use `while let`
|
3 | while let Some(_) = Some(42) {}
| ~~~~~~~~~~~~~~~ ~~~
help: consider using `if let` to clear intent
|
3 | if let Some(_) = Some(42) {}
| ~~~~~~~~~~~~ ~~~
warning: for loop over a `Result`. This is more readably written as an `if let` statement
--> src/main.rs:4:14
|
4 | for _ in Ok::<_, i32>(42) {}
| ^^^^^^^^^^^^^^^^
|
help: to check pattern in a loop use `while let`
|
4 | while let Ok(_) = Ok::<_, i32>(42) {}
| ~~~~~~~~~~~~~ ~~~
help: consider using `if let` to clear intent
|
4 | if let Ok(_) = Ok::<_, i32>(42) {}
| ~~~~~~~~~~ ~~~
-warning: `for-loops-over-fallibles` (bin "for-loops-over-fallibles") generated 2 warnings
- Finished `dev` profile [unoptimized + debuginfo] target(s) in 0.04s
+warning: for loop over a `&Option`. This is more readably written as an `if let` statement
+ --> src/main.rs:7:14
+ |
+7 | for _ in &Some(42) {}
+ | ^^^^^^^^^
+ |
+help: to check pattern in a loop use `while let`
+ |
+7 | while let Some(_) = &Some(42) {}
+ | ~~~~~~~~~~~~~~~ ~~~
+help: consider using `if let` to clear intent
+ |
+7 | if let Some(_) = &Some(42) {}
+ | ~~~~~~~~~~~~ ~~~
+
+warning: for loop over a `&mut Option`. This is more readably written as an `if let` statement
+ --> src/main.rs:8:14
+ |
+8 | for _ in &mut Some(42) {}
+ | ^^^^^^^^^^^^^
+ |
+help: to check pattern in a loop use `while let`
+ |
+8 | while let Some(_) = &mut Some(42) {}
+ | ~~~~~~~~~~~~~~~ ~~~
+help: consider using `if let` to clear intent
+ |
+8 | if let Some(_) = &mut Some(42) {}
+ | ~~~~~~~~~~~~ ~~~
+
+warning: for loop over a `&Result`. This is more readably written as an `if let` statement
+ --> src/main.rs:9:14
+ |
+9 | for _ in &Ok::<_, i32>(42) {}
+ | ^^^^^^^^^^^^^^^^^
+ |
+help: to check pattern in a loop use `while let`
+ |
+9 | while let Ok(_) = &Ok::<_, i32>(42) {}
+ | ~~~~~~~~~~~~~ ~~~
+help: consider using `if let` to clear intent
+ |
+9 | if let Ok(_) = &Ok::<_, i32>(42) {}
+ | ~~~~~~~~~~ ~~~
+
+warning: for loop over a `&mut Result`. This is more readably written as an `if let` statement
+ --> src/main.rs:10:14
+ |
+10 | for _ in &mut Ok::<_, i32>(42) {}
+ | ^^^^^^^^^^^^^^^^^^^^^
+ |
+help: to check pattern in a loop use `while let`
+ |
+10 | while let Ok(_) = &mut Ok::<_, i32>(42) {}
+ | ~~~~~~~~~~~~~ ~~~
+help: consider using `if let` to clear intent
+ |
+10 | if let Ok(_) = &mut Ok::<_, i32>(42) {}
+ | ~~~~~~~~~~ ~~~
+
+warning: `for-loops-over-fallibles` (bin "for-loops-over-fallibles") generated 6 warnings
+ Finished `dev` profile [unoptimized + debuginfo] target(s) in 0.02s
```
</details>
-----
Question:
* ~~Currently, the article `an` is used for `&Option`, and `&mut Option` in the lint diagnostic, since that's what `Option` uses. Is this okay or should it be changed? (likewise, `a` is used for `&Result` and `&mut Result`)~~ The article `a` is used for `&Option`, `&mut Option`, `&Result`, `&mut Result` and (as before) `Result`. Only `Option` uses `an` (as before).
`@rustbot` label +A-lint
Fix OutsideLoop's error suggestion: adding label `'block` for `if` block.
For OutsideLoop we should not suggest add `'block` label in `if` block, or we wiil get another err: block label not supported here.
fixes#123261
With the removal of `LintDiagnostic::msg` / the `msg` param from
lint diag APIs, primary messages for lint diags are always constructed
lazily inside decorator fns rendering this wrapper type unused / useless.
* instead simply set the primary message inside the lint decorator functions
* it used to be this way before [#]101986 which introduced `msg` to prevent
good path delayed bugs (which no longer exist) from firing under certain
circumstances when lints were suppressed / silenced
* this is no longer necessary for various reasons I presume
* it shaves off complexity and makes further changes easier to implement
* inline `LintBuffer::add_lint`, it only had a single use
* update a lint infra example code snippet
* it used the wrong API (the snippet isn't tested)
* presumably the arguments were updated from builder to diag struct style
at some point without updating the method
Rollup of 7 pull requests
Successful merges:
- #125043 (reference type safety invariant docs: clarification)
- #125306 (Force the inner coroutine of an async closure to `move` if the outer closure is `move` and `FnOnce`)
- #125355 (Use Backtrace::force_capture instead of Backtrace::capture in rustc_log)
- #125382 (rustdoc: rename `issue-\d+.rs` tests to have meaningful names (part 7))
- #125391 (Minor serialize/span tweaks)
- #125395 (Remove unnecessary `.md` from the documentation sidebar)
- #125399 (Stop using `to_hir_binop` in codegen)
r? `@ghost`
`@rustbot` modify labels: rollup
Stop using `to_hir_binop` in codegen
This came up in https://github.com/rust-lang/rust/pull/125359#discussion_r1609401311 , and looking into it we can just use the `mir::BinOp`s directly instead of `hir::BinOpKind`s.
(AKA rather than going `mir::BinOp` → `hir::BinOpKind` → `IntPredicate`, just go `mir::BinOp` → `IntPredicate`.)
Use Backtrace::force_capture instead of Backtrace::capture in rustc_log
After https://github.com/rust-lang/rust/pull/125063, the compiler and custom drivers won't automatically set the RUST_BACKTRACE environment variable anymore, so we have to call `Backtrace::force_capture` instead of `Backtrace::capture` to unconditionally capture a backtrace.
rustc_log handles enabling backtraces via env vars itself, so we don't want RUST_BACKTRACE to make a difference.
Force the inner coroutine of an async closure to `move` if the outer closure is `move` and `FnOnce`
See the detailed comment in `upvar.rs`.
Fixes#124867.
Fixes#124487.
r? oli-obk
This has no noticeable effect, but it makes these cases follow the
guidelines in the comments on `Spacing`, which say that `Joint` should
be used "for each token that (a) should be pretty-printed without a
space after it, and (b) is followed by a punctuation token".
These two tokens are both followed by a comma, which is a punctuation
token.
- Name the colon span as `colon_span` to distinguish it from the other
`span` local variable.
- Just use basic pattern matching, which is easier to read than `map_or`.
Typical uses of ThinLTO don't have any use for this as a standalone
file, but distributed ThinLTO uses this to make the linker phase more
efficient. With clang you'd do something like `clang -flto=thin
-fthin-link-bitcode=foo.indexing.o -c foo.c` and then get both foo.o
(full of bitcode) and foo.indexing.o (just the summary or index part of
the bitcode). That's then usable by a two-stage linking process that's
more friendly to distributed build systems like bazel, which is why I'm
working on this area.
I talked some to @teresajohnson about naming in this area, as things
seem to be a little confused between various blog posts and build
systems. "bitcode index" and "bitcode summary" tend to be a little too
ambiguous, and she tends to use "thin link bitcode" and "minimized
bitcode" (which matches the descriptions in LLVM). Since the clang
option is thin-link-bitcode, I went with that to try and not add a new
spelling in the world.
Per @dtolnay, you can work around the lack of this by using `lld
--thinlto-index-only` to do the indexing on regular .o files of
bitcode, but that is a bit wasteful on actions when we already have all
the information in rustc and could just write out the matching minimized
bitcode. I didn't test that at all in our infrastructure, because by the
time I learned that I already had this patch largely written.
An async closure may implement `FnMut`/`Fn` if it has no self-borrows
There's no reason that async closures may not implement `FnMut` or `Fn` if they don't actually borrow anything with the closure's env lifetime. Specifically, #123660 made it so that we don't always need to borrow captures from the closure's env.
See the doc comment on `should_reborrow_from_env_of_parent_coroutine_closure`:
c00957a3e2/compiler/rustc_hir_typeck/src/upvar.rs (L1777-L1823)
If there are no such borrows, then we are free to implement `FnMut` and `Fn` as permitted by our closure's inferred `ClosureKind`.
As far as I can tell, this change makes `async || {}` work in precisely the set of places they used to work before #120361.
Fixes#125247.
r? oli-obk
Disallow cast with trailing braced macro in let-else
This fixes an edge case I noticed while porting #118880 and #119062 to syn.
Previously, rustc incorrectly accepted code such as:
```rust
let foo = &std::ptr::null as &'static dyn std::ops::Fn() -> *const primitive! {
8
} else {
return;
};
```
even though a right curl brace `}` directly before `else` in a `let...else` statement is not supposed to be valid syntax.
Pattern types: Prohibit generic args on const params
Addresses https://github.com/rust-lang/rust/pull/123689/files#r1562676629.
NB: Technically speaking, *not* prohibiting generics args on const params is not a bug as `pattern_types` is an *internal* feature and as such any uncaught misuses of it are considered to be the fault of the user. However, permitting this makes me slightly uncomfortable esp. since we might want to make pattern types available to the public at some point and I don't want this oversight to be able to slip into the language (for comparison, ICEs triggered by the use of internal features are like super fine).
Furthermore, this is an ad hoc fix. A more general fix would be changing the representation of the pattern part of pattern types in such a way that it can reuse preexisting lowering routines for exprs / anon consts. See also this [Zulip discussion](https://rust-lang.zulipchat.com/#narrow/stream/131828-t-compiler/topic/pattern.20type.20HIR.20nodes/near/432410768) and #124650.
Also note that we currently don't properly typeck the pattern of pat tys. This however is out of scope for this PR.
cc ``@oli-obk``
r? ``@spastorino`` as discussed
Add a footer in FileEncoder and check for it in MemDecoder
We have a few reports of ICEs due to decoding failures, where the fault does not lie with the compiler. The goal of this PR is to add some very lightweight and on-by-default validation to the compiler's outputs. If validation fails, we emit a fatal error for rmeta files in general that mentions the path that didn't load, and for incremental compilation artifacts we emit a verbose warning that tries to explain the situation and treat the artifacts as outdated.
The validation currently implemented here is very crude, and yet I think we have 11 ICE reports currently open (you can find them by searching issues for `1002111927320821928687967599834759150`) which this simple validation would have detected. The structure of the code changes here should permit the addition of further validation code, such as a checksum, if it is merited. I would like to have code to detect corruption such as reported in https://github.com/rust-lang/rust/issues/124719, but I'm not yet sure how to do that efficiently, and this PR is already a good size.
The ICE reports I have in mind that this PR would have smoothed over are:
https://github.com/rust-lang/rust/issues/124469https://github.com/rust-lang/rust/issues/123352https://github.com/rust-lang/rust/issues/123376 [^1]
https://github.com/rust-lang/rust/issues/99763https://github.com/rust-lang/rust/issues/93900.
---
[^1]: This one might be a compiler bug, but even if it is I think the workflow described is pushing the envelope of what we can support. This issue is one of the reasons this warning still asks people to file an issue.
offset: allow zero-byte offset on arbitrary pointers
As per prior `@rust-lang/opsem` [discussion](https://github.com/rust-lang/opsem-team/issues/10) and [FCP](https://github.com/rust-lang/unsafe-code-guidelines/issues/472#issuecomment-1793409130):
- Zero-sized reads and writes are allowed on all sufficiently aligned pointers, including the null pointer
- Inbounds-offset-by-zero is allowed on all pointers, including the null pointer
- `offset_from` on two pointers derived from the same allocation is always allowed when they have the same address
This removes surprising UB (in particular, even C++ allows "nullptr + 0", which we currently disallow), and it brings us one step closer to an important theoretical property for our semantics ("provenance monotonicity": if operations are valid on bytes without provenance, then adding provenance can't make them invalid).
The minimum LLVM we require (v17) includes https://reviews.llvm.org/D154051, so we can finally implement this.
The `offset_from` change is needed to maintain the equivalence with `offset`: if `let ptr2 = ptr1.offset(N)` is well-defined, then `ptr2.offset_from(ptr1)` should be well-defined and return N. Now consider the case where N is 0 and `ptr1` dangles: we want to still allow offset_from here.
I think we should change offset_from further, but that's a separate discussion.
Fixes https://github.com/rust-lang/rust/issues/65108
[Tracking issue](https://github.com/rust-lang/rust/issues/117945) | [T-lang summary](https://github.com/rust-lang/rust/pull/117329#issuecomment-1951981106)
Cc `@nikic`
Make sure that the method resolution matches in `note_source_of_type_mismatch_constraint`
`note_source_of_type_mismatch_constraint` is a pile of hacks that I implemented to cover up another pile of hacks.
It does a bunch of re-confirming methods, but it wasn't previously checking that the methods it was looking (back) up were equal to the methods we previously had. This PR adds those checks.
Fixes#118185
Move `#[do_not_recommend]` to the `#[diagnostic]` namespace
This commit moves the `#[do_not_recommend]` attribute to the `#[diagnostic]` namespace. It still requires
`#![feature(do_not_recommend)]` to work.
r? `@compiler-errors`
Translation of the lint message happens when the actual diagnostic is
created, not when the lint is buffered. Generating the message from
BuiltinLintDiag ensures that all required data to construct the message
is preserved in the LintBuffer, eventually allowing the messages to be
moved to fluent.
Remove the `msg` field from BufferedEarlyLint, it is either generated
from the data in the BuiltinLintDiag or stored inside
BuiltinLintDiag::Normal.
Fix incorrect suggestion for undeclared hrtb lifetimes in where clauses.
For poly-trait-ref like `for<'a> Trait<T>` in `T: for<'a> Trait<T> + 'b { }`.
We should merge the hrtb lifetimes: existed `for<'a>` and suggestion `for<'b>` or will get err: [E0316] nested quantification of lifetimes
fixes#122714
Relax restrictions on multiple sanitizers
Most combinations of LLVM sanitizers are legal-enough to enable simultaneously. This change will allow simultaneously enabling ASAN and shadow call stacks on supported platforms.
I used this python script to generate the mutually-exclusive sanitizer combinations:
```python
#!/usr/bin/python3
import subprocess
flags = [
["-fsanitize=address"],
["-fsanitize=leak"],
["-fsanitize=memory"],
["-fsanitize=thread"],
["-fsanitize=hwaddress"],
["-fsanitize=cfi", "-flto", "-fvisibility=hidden"],
["-fsanitize=memtag", "--target=aarch64-linux-android", "-march=armv8a+memtag"],
["-fsanitize=shadow-call-stack"],
["-fsanitize=kcfi", "-flto", "-fvisibility=hidden"],
["-fsanitize=kernel-address"],
["-fsanitize=safe-stack"],
["-fsanitize=dataflow"],
]
for i in range(len(flags)):
for j in range(i):
command = ["clang++"] + flags[i] + flags[j] + ["-o", "main.o", "-c", "main.cpp"]
completed = subprocess.run(command, stderr=subprocess.DEVNULL)
if completed.returncode != 0:
first = flags[i][0][11:].replace('-', '').upper()
second = flags[j][0][11:].replace('-', '').upper()
print(f"(SanitizerSet::{first}, SanitizerSet::{second}),")
```
Refactor documentation for Apple targets
Refactor the documentation for Apple targets in `rustc`'s platform support page to make it clear what the supported OS version is and which environment variables are being read (`*_DEPLOYMENT_TARGET` and `SDKROOT`). This fixes https://github.com/rust-lang/rust/issues/124215.
Note that I've expanded the `aarch64-apple-ios-sim` maintainers `@badboy` and `@deg4uss3r` to include being maintainer of all `*-apple-ios-*` targets. If you do not wish to be so, please state that, then I'll explicitly note that in the docs.
Additionally, I've added myself as co-maintainer of most of these targets.
r? `@thomcc`
I think the documentation you've previously written on tvOS is great, have mostly modified it to have a more consistent formatting with the rest of the Apple target.
I recognize that there's quite a few changes here, feel free to ask about any of them!
---
CC `@simlay` `@Nilstrieb`
`@rustbot` label O-apple
Add `IntoIterator` for `Box<[T]>` + edition 2024-specific lints
* Adds a similar method probe opt-out mechanism to the `[T;N]: IntoIterator` implementation for edition 2021.
* Adjusts the relevant lints (shadowed `.into_iter()` calls, new source of method ambiguity).
* Adds some tests.
* Took the liberty to rework the logic in the `ARRAY_INTO_ITER` lint, since it was kind of confusing.
Based mostly off of #116607.
ACP: rust-lang/libs-team#263
References #59878
Tracking for Rust 2024: https://github.com/rust-lang/rust/issues/123759
Crater run was done here: https://github.com/rust-lang/rust/pull/116607#issuecomment-1770293013
Consensus afaict was that there is too much breakage, so let's do this in an edition-dependent way much like `[T; N]: IntoIterator`.
Follow-up fixes to `report_return_mismatched_types`
Some renames, simplifications, fixes, etc. Follow-ups to #123804. I don't think it totally disentangles this code, but it does remove some of the worst offenders on the "I am so confused" scale (e.g. `get_node_fn_decl`).
Uplift `RegionVid`, `TermKind` to `rustc_type_ir`, and `EagerResolver` to `rustc_next_trait_solver`
- Uplift `RegionVid`. This was complicated due to the fact that we implement `polonius_engine::Atom` for `RegionVid` -- but I just separated that into `PoloniusRegionVid`, and added `From`/`Into` impls so it can be defined in `rustc_borrowck` separately. Coherence 😵
- Change `InferCtxtLike` to expose `opportunistically_resolve_{ty,ct,lt,int,float}_var` so that we can uplift `EagerResolver` for use in the canonicalization methods.
- Uplift `TermKind` much like `GenericArgKind`
All of this is miscellaneous dependencies for making more `EvalCtxt` methods generic.
track cycle participants per root
The search graph may have multiple roots, e.g. in
```
A :- B
B :- A, C
C :- D
D :- C
```
we first encounter the `A -> B -> A` cycle which causes `A` to be a root. We then later encounter the `C -> D -> C` cycle as a nested goal of `B`. This cycle is completely separate and `C` will get moved to the global cache. This previously caused us to use `[B, D]` as the `cycle_participants` for `C` and `[]` for `A`.
split off from #125167 as I would like to merge this change separately and will rebase that PR on top of this one. There is no test for this issue and I don't quite know how to write one. It is probably worth it to generalize the search graph to enable us to write unit tests for it.
r? `@compiler-errors`
Note for E0599 if shadowed bindings has the method.
implement #123558
Use a visitor to find earlier shadowed bingings which has the method.
r? ``@estebank``
Update `unexpected_cfgs` lint for Cargo new `check-cfg` config
This PR updates the diagnostics output of the `unexpected_cfgs` lint for Cargo new `check-cfg` config.
It's a simple and cost-less alternative to the build-script `cargo::rustc-check-cfg` instruction.
```toml
[lints.rust]
unexpected_cfgs = { level = "warn", check-cfg = ['cfg(foo, values("bar"))'] }
```
This PR also adds a Cargo specific section regarding check-cfg and Cargo inside rustc's book (motivation is described inside the file, but mainly check-cfg is a rustc feature not a Cargo one, Cargo only enabled the feature, it does not own it; T-cargo even considers the `check-cfg` lint config to be an implementation detail).
This PR also updates the links to refer to that sub-page when using Cargo from rustc.
As well as updating the lint doc to refer to the check-cfg docs.
~**Not to be merged before https://github.com/rust-lang/cargo/pull/13913 reaches master!**~ (EDIT: merged in https://github.com/rust-lang/rust/pull/125237)
`@rustbot` label +F-check-cfg
r? `@fmease` *(feel free to roll)*
Fixes https://github.com/rust-lang/rust/issues/124800
cc `@epage` `@weihanglo`
coverage: Memoize and simplify counter expressions
When creating coverage counter expressions as part of coverage instrumentation, we often end up creating obviously-redundant expressions like `c1 + (c0 - c1)`, which is equivalent to just `c0`.
To avoid doing so, this PR checks when we would create an expression matching one of 5 patterns, and uses the simplified form instead:
- `(a - b) + b` → `a`.
- `(a + b) - b` → `a`.
- `(a + b) - a` → `b`.
- `a + (b - a)` → `b`.
- `a - (a - b)` → `b`.
Of all the different ways to combine 3 operands and 2 operators, these are the patterns that allow simplification.
(Some of those patterns currently don't occur in practice, but are included anyway for completeness, to avoid having to add them later as branch coverage and MC/DC coverage support expands.)
---
This PR also adds memoization for newly-created (or newly-simplified) counter expressions, to avoid creating duplicates.
This currently makes no difference to the final mappings, but is expected to be useful for MC/DC coverage of match expressions, as proposed by https://github.com/rust-lang/rust/pull/124278#issuecomment-2106754753.
Suggest setting lifetime in borrowck error involving types with elided lifetimes
```
error: lifetime may not live long enough
--> $DIR/ex3-both-anon-regions-both-are-structs-2.rs:7:5
|
LL | fn foo(mut x: Ref, y: Ref) {
| ----- - has type `Ref<'_, '1>`
| |
| has type `Ref<'_, '2>`
LL | x.b = y.b;
| ^^^^^^^^^ assignment requires that `'1` must outlive `'2`
|
help: consider introducing a named lifetime parameter
|
LL | fn foo<'a>(mut x: Ref<'a, 'a>, y: Ref<'a, 'a>) {
| ++++ ++++++++ ++++++++
```
As can be seen above, it currently doesn't try to compare the `ty::Ty` lifetimes that diverged vs the `hir::Ty` to correctly suggest the following
```
help: consider introducing a named lifetime parameter
|
LL | fn foo<'a>(mut x: Ref<'_, 'a>, y: Ref<'_, 'a>) {
| ++++ ++++++++ ++++++++
```
but I believe this to still be an improvement over the status quo.
Fix#40990.
Make `EvalCtxt` generic over `InferCtxtLike`
...but don't change any of the impls, yet! These can get uplifted as we add more methods to `InferCtxtLike`/`Interner` :3
This is built on top of #125230.
r? lcnr
defrost `RUST_MIN_STACK=ice rustc hello.rs`
I didn't think too hard about testing my previous PR rust-lang/rust#122847 which makes our stack overflow handler assist people in discovering the `RUST_MIN_STACK` variable (which apparently is surprisingly useful for Really Big codebases). After it was merged, some useful comments left in a drive-by review led me to discover I had added an ICE. This reworks the code a bit to explain the rationale, remove the ICE that I introduced, and properly test one of the diagnostics.
fix suggestion in E0373 for !Unpin coroutines
Coroutines can be prefixed with the `static` keyword to make them
`!Unpin`.
However, given the following function:
```rust
fn check() -> impl Sized {
let x = 0;
#[coroutine]
static || {
yield;
x
}
}
```
We currently suggest prefixing `move` before `static`, which is
syntactically incorrect:
```
error[E0373]: coroutine may outlive the current function, but it borrows
...
--> src/main.rs:6:5
|
6 | static || {
| ^^^^^^^^^ may outlive borrowed value `x`
7 | yield;
8 | x
| - `x` is borrowed here
|
note: coroutine is returned here
--> src/main.rs:6:5
|
6 | / static || {
7 | | yield;
8 | | x
9 | | }
| |_____^
help: to force the coroutine to take ownership of `x` (and any other
referenced variables), use the `move` keyword
| // this is syntactically incorrect, it should be `static move ||`
6 | move static || {
| ++++
```
This PR suggests adding `move` after `static` for these coroutines.
I also added a UI test for this case.
Never type unsafe lint improvements
- Move linting code to a separate method
- Remove mentions of `core::convert::absurd` (#124311 was rejected)
- Make the lint into FCW
The last thing is a bit weird though. On one hand it should be `EditionSemanticsChange(2024)`, but on the other hand it shouldn't, because we also plan to break it on all editions some time later. _Also_, it's weird that we don't have `FutureReleaseSemanticsChangeReportInDeps`, IMO "this might cause UB in a future release" is important enough to be reported in deps...
IMO we ought to have three enums instead of [`FutureIncompatibilityReason`](https://doc.rust-lang.org/nightly/nightly-rustc/rustc_lint_defs/enum.FutureIncompatibilityReason.html#):
```rust
enum IncompatibilityWhen {
FutureRelease,
Edition(Edition),
}
enum IncompatibilyWhat {
Error,
SemanticChange,
}
enum IncompatibilityReportInDeps {
No,
Yes,
}
```
Tracking:
- https://github.com/rust-lang/rust/issues/123748
An earlier commit included the change for a suggestion here.
Unfortunately, it also used unwrap instead of dying properly.
Roll out the ~~rice paper~~ EarlyDiagCtxt before we do anything that
might leave a mess.
Coroutines can be prefixed with the `static` keyword to make them
`!Unpin`.
However, given the following function:
```rust
fn check() -> impl Sized {
let x = 0;
#[coroutine]
static || {
yield;
x
}
}
```
We currently suggest prefixing `move` before `static`, which is
syntactically incorrect:
```
error[E0373]: coroutine may outlive the current function, but it borrows
...
--> src/main.rs:6:5
|
6 | static || {
| ^^^^^^^^^ may outlive borrowed value `x`
7 | yield;
8 | x
| - `x` is borrowed here
|
note: coroutine is returned here
--> src/main.rs:6:5
|
6 | / static || {
7 | | yield;
8 | | x
9 | | }
| |_____^
help: to force the coroutine to take ownership of `x` (and any other
referenced variables), use the `move` keyword
| // this is syntactically incorrect, it should be `static move ||`
6 | move static || {
| ++++
```
This PR suggests adding `move` after `static` for these coroutines.
chore: Remove repeated words (extension of #124924)
When I saw #124924 I thought "Hey, I'm sure that there are far more than just two typos of this nature in the codebase". So here's some more typo-fixing.
Some found with regex, some found with a spellchecker. Every single one manually reviewed by me (along with hundreds of false negatives by the tools)
