This does not yet handle the case of mixed deref patterns with normal
constructors; it'll ICE in `Constructor::is_covered_by`. That'll be
fixed in a later commit.
Rename `graph::implementation::Graph` to `LinkedGraph`
One of the more confusing parts of the `rustc_data_structures::graph` module is this mysteriously-named “Graph” type, which turns out to be an older standalone graph implementation that predates the traits used by the rest of the graph module.
This graph type is still used in a couple of places (for reporting certain lifetime errors, and by certain debugging/test-only checks of the query dependency graph), but hasn't had much attention in years.
This PR renames that old graph type from `implementation::Graph` to `linked_graph::LinkedGraph` to give it a more distinct identity (and make existing uses easier to find), and adds some notes to gently discourage any further use in new code.
No functional change.
coverage: Only merge adjacent coverage spans
For a long time, coverage instrumentation has automatically “merged” spans with the same control-flow into a smaller number of larger spans, even when the spans being merged are not overlapping or adjacent. This causes any source text between the original spans to be included in the merged span, which is then associated with an execution count when shown in coverage reports.
That approach causes a number of problems:
- The intervening source text can contain all sorts of things that shouldn't really be marked as executable code (e.g. nested items, parts of macro invocations, long comments). In some cases we have complicated workarounds (e.g. bucketing to avoid merging spans across nested items), but in other cases there isn't much we can do.
- Merging can have aesthetically weird effects, such as including unbalanced parentheses, because the merging process doesn't really understand what it's doing at a source code level.
- It generally leads to an accumulation of piled-on heuristics and special cases that give decent-looking results, but are fiendishly difficult to modify or replace.
Therefore, this PR aims to abolish the merging of non-adjacent coverage spans.
The big tradeoff here is that the resulting coverage metadata (embedded in the instrumented binary) tends to become larger, because the overall number of distinct spans has increased. That's unfortunate, but I see it as the inevitable cost of cleaning up the messes and inaccuracies that were caused by the old approach. And the resulting spans do tend to be more accurate to the program's actual control-flow.
---
The `.coverage` snapshot changes give an indication of how this PR will affect user-visible coverage reports. In many cases the changes to reporting are minor or even nonexistent, despite substantial changes to the metadata (as indicated by `.cov-map` snapshots).
---
try-job: aarch64-gnu
Rollup of 4 pull requests
Successful merges:
- #140135 (Unify sidebar buttons to use the same image)
- #140632 (add a test for issue rust-lang/rust#81317)
- #140658 (`deref_patterns`: let string and byte string literal patterns peel references and smart pointers before matching)
- #140681 (Don't ignore compiler stderr in `lib-defaults.rs`)
r? `@ghost`
`@rustbot` modify labels: rollup
`deref_patterns`: let string and byte string literal patterns peel references and smart pointers before matching
This follows up on #140028. Together, they allow using string and byte string literal patterns to match on smart pointers when `deref_patterns` is enabled. In particular, string literals can now match on `String`, subsuming the functionality of the `string_deref_patterns` feature.
More generally, this works by letting literals peel references (and smart pointers) before matching, similar to most other patterns, providing an answer to #44849. Though it's only partially implemented at this point: this doesn't yet let named const patterns peel before matching. The peeling logic is general enough to support named consts, but the typing rules for named const patterns would need adjustments to feel consistent (e.g. arrays would need rules to be usable as slices, and `const STR: &'static str` wouldn't be able to match on a `String` unless a rule was added to let it be used where a `str` is expected, similar to what #140028 did for literals).
This also allows string and byte string patterns to match on mutable references, following up on https://github.com/rust-lang/rust/pull/140028#discussion_r2053927512. Rather than forward the mutability of the scrutinee to literal patterns, I've opted to peel `&mut`s from the scrutinee. From a design point of view, this makes the behavior consistent with what would be expected from deref coercions using the methodology in the next paragraph. From a diagnostics point of view, this avoids labeling string and byte string patterns as "mutable references", which I think could be confusing. See [`byte-string-type-errors.rs`](https://github.com/rust-lang/rust/compare/master...dianne:rust:lit-deref-pats-p2?expand=1#diff-4a0dd9b164b67c706751f3c0b5762ddab08bcef05a91972beb0190c6c1cd3706) for how the diagnostics look.
At a high level, the peeling logic implemented here tries to mimic how deref coercions work for expressions: we peel references (and smart pointers) from the scrutinee until the pattern can match against it, and no more. This is primarily tested by [`const-pats-do-not-mislead-inference.rs`](https://github.com/rust-lang/rust/compare/master...dianne:rust:lit-deref-pats-p2?expand=1#diff-19afc05b8aae9a30fe4a3a8c0bc2ab2c56b58755a45cdf5c12be0d5e83c4739d). To illustrate the connection, I wasn't sure if this made sense to include in the test file, but I've translated those tests to make sure they give the same inference results as deref coercions: [(playground)](https://play.rust-lang.org/?version=stable&mode=debug&edition=2024&gist=1869744cb9cdfed71a686990aadf9fe1). In each case, a reference to the scrutinee is coerced to have the type of the pattern (under a reference).
Tracking issue for deref patterns: #87121
r? `@oli-obk`
cc `@Nadrieril`
Be a bit more relaxed about not yet constrained infer vars in closure upvar analysis
See the writeup in `tests/ui/closures/opaque-upvar.rs`.
TL;DR is that this has to do with the fact that the recursive revealing uses, which have not yet been constrained from the defining use by the time that closure upvar inference is performed, remain as infer vars during upvar analysis. We don't really care, though, since anywhere we structurally match on a type in upvar analysis, we already call `structurally_resolve_type` right before `.kind()`, which would emit a true ambiguity error.
Fixes https://github.com/rust-lang/trait-system-refactor-initiative/issues/197
r? lcnr
Fix RustAnalyzer discovery of rustc's `stable_mir` crate
This fixes issues with RustAnalyzer not finding `stable_mir` crate since RA discovery traverses the dependency graph of `rustc_driver` crate.
This change also aligns with the long term architecture plan for these crates, since we are moving towards having stable_mir depend on rustc_smir and not the other way around. See [this doc](https://hackmd.io/jBRkZLqAQL2EVgwIIeNMHg) for more details.
I believe a similar function will come handy eventually for `stable_mir` users, but I'm keeping it as part of `rustc_internal` since its current format initializes the StableMir context and requires `TyCtxt`.
Finally, I added the `rustc_internal` module re-export under a feature since the APIs from this module shall not be stabilized.
Fix `-Zremap-path-scope` rmeta handling
This PR fixes the conditional remapping (`-Zremap-path-scope`) of rmeta file paths ~~by using the `debuginfo` scope~~ by conditionally embedding the local path in addition to the remapped path.
Fixes https://github.com/rust-lang/rust/issues/139217
Make `-Zfixed-x18` into a target modifier
As part of #136966, the `-Zfixed-x18` flag should be turned into a target modifier. This is a blocker to stabilization of the flag. The flag was originally added in #124655 and the MCP for its addition is [MCP#748](https://github.com/rust-lang/compiler-team/issues/748).
On some aarch64 targets, the x18 register is used as a temporary caller-saved register by default. When the `-Zfixed-x18` flag is passed, this is turned off so that the compiler doesn't use the x18 register. This allows end-users to use the x18 register for other purposes. For example, by accessing it with inline asm you can use the register as a very efficient thread-local variable. Another common use-case is to store the stack pointer needed by the shadow-call-stack sanitizer. There are also some aarch64 targets where not using x18 is the default – in those cases the flag is a no-op.
Note that this flag does not *on its own* cause an ABI mismatch. What actually causes an ABI mismatch is when you have different compilation units that *disagree* on what it should be used for. But having a CU that uses it and another CU that doesn't normally isn't enough to trigger an ABI problem. However, we still consider the flag to be a target modifier in all cases, since it is assumed that you are passing the flag because you intend to assign some other meaning to the register. Rejecting all flag mismatches even if not all are unsound is consistent with [RFC#3716](https://rust-lang.github.io/rfcs/3716-target-modifiers.html). See the headings "not all mismatches are unsound" and "cases that are not caught" for additional discussion of this.
On aarch64 targets where `-Zfixed-x18` is not a no-op, it is an error to pass `-Zsanitizer=shadow-call-stack` without also passing `-Zfixed-x18`.
`fn check_opaque_type_parameter_valid` defer error
Will be used in #139587 to silence opaque type errors if there are other borrowck failures. I think it can be merged separately.
r? `@compiler-errors`
Removing rustc_type_ir in the rustc_infer codebase
cc #138449
This is a second refactoring of rustc_type_ir to use rustc_middle instead, this time that's for rustc_infer
mir-opt: execute MatchBranchSimplification after GVN
This can provide more opportunities for MatchBranchSimplification.
Currently, rustc does not optimize the following code into a single statement at mir-opt, and this PR fixes the first case.
```rust
pub fn match1(c: bool, v1: i32, v2: i32) -> i32 {
if c { v1 - v2 } else { v1 - v2 }
}
pub fn match2(c: bool, v1: i32) -> i32 {
if c { v1 - 1 } else { v1 - 1 }
}
```
https://rust.godbolt.org/z/Y8xPMjrfM
r? mir-opt
Remove global `next_disambiguator` state and handle it with a `DisambiguatorState` type
This removes `Definitions.next_disambiguator` as it doesn't guarantee deterministic def paths when `create_def` is called in parallel. Instead a new `DisambiguatorState` type is passed as a mutable reference to `create_def` to help create unique def paths. `create_def` calls with distinct `DisambiguatorState` instances must ensure that that the def paths are unique without its help.
Anon associated types did rely on this global state for uniqueness and are changed to use (method they're defined in + their position in the method return type) as the `DefPathData` to ensure uniqueness. This also means that the method they're defined in appears in error messages, which is nicer.
`DefPathData::NestedStatic` is added to use for nested data inside statics instead of reusing `DefPathData::AnonConst` to avoid conflicts with those.
cc `@oli-obk`
Initial support for dynamically linked crates
This PR is an initial implementation of [rust-lang/rfcs#3435](https://github.com/rust-lang/rfcs/pull/3435) proposal.
### component 1: interface generator
Interface generator - a tool for generating a stripped version of crate source code. The interface is like a C header, where all function bodies are omitted. For example, initial crate:
```rust
#[export]
#[repr(C)]
pub struct S {
pub x: i32
}
#[export]
pub extern "C" fn foo(x: S) {
m1::bar(x);
}
pub fn bar(x: crate::S) {
// some computations
}
```
generated interface:
```rust
#[export]
#[repr(C)]
pub struct S {
pub x: i32,
}
#[export]
pub extern "C" fn foo(x: S);
pub fn bar(x: crate::S);
```
The interface generator was implemented as part of the pretty-printer. Ideally interface should only contain exportable items, but here is the first problem:
- pass for determining exportable items relies on privacy information, which is totally available only in HIR
- HIR pretty-printer uses pseudo-code(at least for attributes)
So, the interface generator was implemented in AST. This has led to the fact that non-exportable items cannot be filtered out, but I don't think this is a major issue at the moment.
To emit an interface use a new `sdylib` crate type which is basically the same as `dylib`, but it doesn't contain metadata, and also produces the interface as a second artifact. The current interface name is `lib{crate_name}.rs`.
#### Why was it decided to use a design with an auto-generated interface?
One of the main objectives of this proposal is to allow building the library and the application with different compiler versions. This requires either a metadata format compatible across rustc versions or some form of a source code. The option with a stable metadata format has not been investigated in detail, but it is not part of RFC either. Here is the the related discussion: https://github.com/rust-lang/rfcs/pull/3435#discussion_r1202872373
Original proposal suggests using the source code for the dynamic library and all its dependencies. Metadata is obtained from `cargo check`. I decided to use interface files since it is more or less compatible with the original proposal, but also allows users to hide the source code.
##### Regarding the design with interfaces
in Rust, files generally do not have a special meaning, unlike C++. A translation unit i.e. a crate is not a single file, it consists of modules. Modules, in turn, can be declared either in one file or divided into several. That's why the "interface file" isn't a very coherent concept in Rust. I would like to avoid adding an additional level of complexity for users until it is proven necessary. Therefore, the initial plan was to make the interfaces completely invisible to users i. e. make them auto-generated. I also planned to put them in the dylib, but this has not been done yet. (since the PR is already big enough, I decided to postpone it)
There is one concern, though, which has not yet been investigated(https://github.com/rust-lang/rust/pull/134767#issuecomment-2736471828):
> Compiling the interface as pretty-printed source code doesn't use correct macro hygiene (mostly relevant to macros 2.0, stable macros do not affect item hygiene). I don't have much hope for encoding hygiene data in any stable way, we should rather support a way for the interface file to be provided manually, instead of being auto-generated, if there are any non-trivial requirements.
### component 2: crate loader
When building dynamic dependencies, the crate loader searches for the interface in the file system, builds the interface without codegen and loads it's metadata. Routing rules for interface files are almost the same as for `rlibs` and `dylibs`. Firstly, the compiler checks `extern` options and then tries to deduce the path himself.
Here are the code and commands that corresponds to the compilation process:
```rust
// simple-lib.rs
#![crate_type = "sdylib"]
#[extern]
pub extern "C" fn foo() -> i32 {
42
}
```
```rust
// app.rs
extern crate simple_lib;
fn main() {
assert!(simple_lib::foo(), 42);
}
```
```
// Generate interface, build library.
rustc +toolchain1 lib.rs
// Build app. Perhaps with a different compiler version.
rustc +toolchain2 app.rs -L.
```
P.S. The interface name/format and rules for file system routing can be changed further.
### component 3: exportable items collector
Query for collecting exportable items. Which items are exportable is defined [here](https://github.com/m-ou-se/rfcs/blob/export/text/0000-export.md#the-export-attribute) .
### component 4: "stable" mangling scheme
The mangling scheme proposed in the RFC consists of two parts: a mangled item path and a hash of the signature.
#### mangled item path
For the first part of the symbol it has been decided to reuse the `v0` mangling scheme as it much less dependent on compiler internals compared to the `legacy` scheme.
The exception is disambiguators (https://doc.rust-lang.org/rustc/symbol-mangling/v0.html#disambiguator):
For example, during symbol mangling rustc uses a special index to distinguish between two impls of the same type in the same module(See `DisambiguatedDefPathData`). The calculation of this index may depend on private items, but private items should not affect the ABI. Example:
```rust
#[export]
#[repr(C)]
pub struct S<T>(pub T);
struct S1;
pub struct S2;
impl S<S1> {
extern "C" fn foo() -> i32 {
1
}
}
#[export]
impl S<S2> {
// Different symbol names can be generated for this item
// when compiling the interface and source code.
pub extern "C" fn foo() -> i32 {
2
}
}
```
In order to make disambiguation independent of the compiler version we can assign an id to each impl according to their relative order in the source code.
The second example is `StableCrateId` which is used to disambiguate different crates. `StableCrateId` consists of crate name, `-Cmetadata` arguments and compiler version. At the moment, I have decided to keep only the crate name, but a more consistent approach to crate disambiguation could be added in the future.
Actually, there are more cases where such disambiguation can be used. For instance, when mangling internal rustc symbols, but it also hasn't been investigated in detail yet.
#### hash of the signature
Exportable functions from stable dylibs can be called from safe code. In order to provide type safety, 128 bit hash with relevant type information is appended to the symbol ([description from RFC](https://github.com/m-ou-se/rfcs/blob/export/text/0000-export.md#name-mangling-and-safety)). For now, it includes:
- hash of the type name for primitive types
- for ADT types with public fields the implementation follows [this](https://github.com/m-ou-se/rfcs/blob/export/text/0000-export.md#types-with-public-fields) rules
`#[export(unsafe_stable_abi = "hash")]` syntax for ADT types with private fields is not yet implemented.
Type safety is a subtle thing here. I used the approach from RFC, but there is the ongoing research project about it. [https://rust-lang.github.io/rust-project-goals/2025h1/safe-linking.html](https://rust-lang.github.io/rust-project-goals/2025h1/safe-linking.html)
### Unresolved questions
Interfaces:
1. Move the interface generator to HIR and add an exportable items filter.
2. Compatibility of auto-generated interfaces and macro hygiene.
3. There is an open issue with interface files compilation: https://github.com/rust-lang/rust/pull/134767#issuecomment-2736471828
4. Put an interface into a dylib.
Mangling scheme:
1. Which information is required to ensure type safety and how should it be encoded? ([https://rust-lang.github.io/rust-project-goals/2025h1/safe-linking.html](https://rust-lang.github.io/rust-project-goals/2025h1/safe-linking.html))
2. Determine all other possible cases, where path disambiguation is used. Make it compiler independent.
We also need a semi-stable API to represent types. For example, the order of fields in the `VariantDef` must be stable. Or a semi-stable representation for AST, which ensures that the order of the items in the code is preserved.
There are some others, mentioned in the proposal.
Refactor rustc_on_unimplemented's filter parser
Followup to https://github.com/rust-lang/rust/pull/139091; I plan on moving most of this code into `rustc_attr_parsing` at some point, but want to land this separately first.
I have taken care to preserve the original behavior as much as I could:
- All but one of the new error variants are replacements for the ones originally emitted by the cfg parsing machinery; so these errors are not "new".
- the `InvalidFlag` variant is new, this PR turns this (from being ignored and silently doing nothing) into an error:
```rust
#[rustc_on_unimplemented(on(something, message = "y"))]
//~^ ERROR invalid boolean flag
//~^^ NOTE expected one of `crate_local`, `direct` or `from_desugaring`, not `something`
trait InvalidFlag {}
```
This does not occur anywhere except in this test. I couldn't find a way that I liked to keep allowing this or to do nothing, erroring was the cleanest solution.
- There are a bunch of FIXME throughout this and the previous PR, I plan on addressing those in follow up prs..
Finally, this gets rid of the "longest" dependency in rustc:
Async drop source info fix for proxy-drop-coroutine
Fixes crash at debug info generation: https://github.com/rust-lang/rust/issues/140426 .
Also, the submitted example requires sync Drop implementation too.
Because sync version is required for unwind and when drop is performed in sync context (sync function).
Probably, it is also needed to add such a lint/error about missed `impl Drop`, when there is `impl AsyncDrop`.
Fix description: even minimal, empty coroutine (for proxy-coroutine) has 3 states and the source info array should have 3 elements too.
```
#![feature(async_drop)]
use std::future::AsyncDrop;
use std::pin::Pin;
#[tokio::main(flavor = "current_thread")]
async fn main() {
let _st = St;
}
struct St;
impl AsyncDrop for St {
async fn drop(self: Pin<&mut Self>) {
println!("123");
}
}
```
Allow linking rustc and rustdoc against the same single tracing crate
Alternate title: _Ignore "a global default trace dispatcher has already been set" error in Rustdoc_
By consecutively initializing `tracing` and `rustc_log`, Rustdoc assumes that these involve 2 different tracing crates.
I would like to be able to build rustdoc against the same tracing crate that rustc_log is also built against. Previously this arrangement would crash rustdoc:
```console
thread 'main' panicked at rust/compiler/rustc_log/src/lib.rs:142:65:
called `Result::unwrap()` on an `Err` value: SetGlobalDefaultError("a global default trace dispatcher has already been set")
stack backtrace:
0: rust_begin_unwind
1: core::panicking::panic_fmt
2: core::result::unwrap_failed
3: rustc_log::init_logger
4: rustc_driver_impl::init_logger
5: rustdoc::main
note: Some details are omitted, run with `RUST_BACKTRACE=full` for a verbose backtrace.
error: the compiler unexpectedly panicked. this is a bug.
note: we would appreciate a bug report: https://github.com/rust-lang/rust/issues/new?labels=C-bug%2C+I-ICE%2C+T-rustdoc&template=ice.md
note: please make sure that you have updated to the latest nightly
query stack during panic:
end of query stack
```
Don't name variables from external macros in borrow errors.
This came up as part of the expansion of format_args. However, it's a more general problem (and now solution).
I noticed that this does change another test, moving out of fields in derives on packed struct. However, I think this is a better error simply because it used to refer to `other.0` which is an implementation detail which doesn't really make sense.
cc `@m-ou-se`
Rollup of 7 pull requests
Successful merges:
- #139675 (Add the AVX10 target features)
- #140286 (Check if format argument is identifier to avoid error err-emit)
- #140456 (Fix test simd/extract-insert-dyn on s390x)
- #140551 (Move some tests out of tests/ui)
- #140588 (Adjust some ui tests re. target-dependent errors)
- #140617 (Report the `unsafe_attr_outside_unsafe` lint at the closest node)
- #140626 (allow `#[rustfmt::skip]` in combination with `#[naked]`)
r? `@ghost`
`@rustbot` modify labels: rollup
allow `#[rustfmt::skip]` in combination with `#[naked]`
fixes https://github.com/rust-lang/rust/issues/140623
We very deliberately use an allowlist to prevent weird interactions with `#[naked]`, hopefully we've now found all of the useful combinations.
cc `@Amanieu`
Report the `unsafe_attr_outside_unsafe` lint at the closest node
This PR have `AstValidation` track a linting node id and then uses it when reporting the `unsafe_attr_outside_unsafe` lint, so that instead of being bound at the crate-root, `#[allow]` of the lint works at any node.
Fixesrust-lang/rust#140602
r? `@jieyouxu`
