Change `AttrArgs::Eq` to a struct variant
Cleanups for simplifying https://github.com/rust-lang/rust/pull/131808
Basically changes `AttrArgs::Eq` to a struct variant and then avoids several matches on `AttrArgsEq` in favor of methods on it. This will make future refactorings simpler, as they can either keep methods or switch to field accesses without having to restructure code
fix ICE when promoted has layout size overflow
Turns out there is no reason to distinguish `tainted_by_errors` and `can_be_spurious` here, we can just track whether we allow this even in "infallible" constants.
Fixes https://github.com/rust-lang/rust/issues/125476
Use c"lit" for CStrings without unwrap
I've reviewed uses of `CString::new("lit")`.
Some could be changed to `c"lit"`. Some could be changed to `c"lit".to_owned()`, avoiding an `unwrap()`.
Many `CString` documentation examples could be simplified. I deliberately haven't changed all the examples to use the exact same expression, so that they can demonstrate many ways of creating `CString`s.
I've left UI tests mostly unchanged, because `c""` requires edition 2021, but most UI tests use 2015, and I didn't want to accidentally change what the tests are testing.
Move `Const::{from_anon_const,try_from_lit}` to hir_ty_lowering
Fixes#128176.
This accomplishes one of the followup items from #131081.
These operations are much more about lowering the HIR than about
`Const`s themselves. They fit better in hir_ty_lowering with
`lower_const_arg` (formerly `Const::from_const_arg`) and the rest.
To accomplish this, `const_evaluatable_predicates_of` had to be changed
to not use `from_anon_const` anymore. Instead of visiting the HIR and
lowering anon consts on the fly, it now visits the `rustc_middle::ty`
data structures instead and directly looks for `UnevaluatedConst`s. This
approach was proposed in:
https://github.com/rust-lang/rust/pull/131081#discussion_r1821189257
r? `@BoxyUwU`
show forbidden_lint_groups in future-compat reports
Part of https://github.com/rust-lang/rust/issues/81670. This has been a future-compat lint for a while, time to dial it up to show up in reports.
These operations are much more about lowering the HIR than about
`Const`s themselves. They fit better in hir_ty_lowering with
`lower_const_arg` (formerly `Const::from_const_arg`) and the rest.
To accomplish this, `const_evaluatable_predicates_of` had to be changed
to not use `from_anon_const` anymore. Instead of visiting the HIR and
lowering anon consts on the fly, it now visits the `rustc_middle::ty`
data structures instead and directly looks for `UnevaluatedConst`s. This
approach was proposed in:
https://github.com/rust-lang/rust/pull/131081#discussion_r1821189257
`impl Default for EarlyDiagCtxt`
for small rustc_driver programs, most of their imports will currently be related to diagnostics. this change simplifies their code so it's more clear what in the driver is modified from the default.
this is especially important for external drivers which are out of tree and not updated in response to breaking changes. for these drivers, each import is a liability for future code, since it can be broken when refactors happen.
here is an example driver which is simplified by these changes:
```diff
diff --git a/src/main.rs b/src/main.rs
index f81aa3e..11e5f18 100644
--- a/src/main.rs
+++ b/src/main.rs
`@@` -1,16 +1,8 `@@`
#![feature(rustc_private)]
extern crate rustc_driver;
extern crate rustc_interface;
-extern crate rustc_errors;
-extern crate rustc_session;
use rustc_driver::Callbacks;
-use rustc_errors::{emitter::HumanReadableErrorType, ColorConfig};
use rustc_interface::interface;
-use rustc_session::config::ErrorOutputType;
-use rustc_session::EarlyDiagCtxt;
struct DisableSafetyChecks;
`@@` -26,11 +18,7 `@@` fn main() {
"https://github.com/jyn514/jyn514.github.io/issues/new",
|_| (),
);
- let handler = EarlyDiagCtxt::new(ErrorOutputType::HumanReadable(
- HumanReadableErrorType::Default,
- ColorConfig::Auto,
- ));
- rustc_driver::init_rustc_env_logger(&handler);
+ rustc_driver::init_rustc_env_logger(&Default::default());
std::process::exit(rustc_driver::catch_with_exit_code(move || {
let args: Vec<String> = std::env::args().collect();
rustc_driver::RunCompiler::new(&args, &mut DisableSafetyChecks).run()
```
remove `Ty::is_copy_modulo_regions`
Using these functions is likely incorrect if an `InferCtxt` is available, I moved this function to `TyCtxt` (and added it to `LateContext`) and added a note to the documentation that one should prefer `Infer::type_is_copy_modulo_regions` instead.
I didn't yet move `is_sized` and `is_freeze`, though I think we should move these as well.
r? `@compiler-errors` cc #132279
Eliminate magic numbers from expression precedence
Context: see https://github.com/rust-lang/rust/pull/133140.
This PR continues on backporting Syn's expression precedence design into rustc. Rustc's design used mysterious integer quantities represented variously as `i8` or `usize` (e.g. `PREC_CLOSURE = -40i8`), a special significance around `0` that is never named, and an extra `PREC_FORCE_PAREN` precedence level that does not correspond to any expression. Syn's design uses a C-like enum with variants that clearly correspond to specific sets of expression kinds.
This PR is a refactoring that has no intended behavior change on its own, but it unblocks other precedence work that rustc's precedence design was poorly suited to accommodate.
- Asymmetrical precedence, so that a pretty-printer can tell `(return 1) + 1` needs parens but `1 + return 1` does not.
- Squashing the `Closure` and `Jump` cases into a single precedence level.
- Numerous remaining false positives and false negatives in rustc pretty-printer's parenthesization of macro metavariables, for example in `$e < rhs` where $e is `lhs as Thing<T>`.
FYI `@fmease` — you don't need to review if rustbot picks someone else, but you mentioned being interested in the followup PRs.
check local cache even if global is usable
we store overflow errors locally, even if we can otherwise use the global cache for this goal. should fix#133616, didn't test it locally yet as diesel tends to hit an unrelated debug assertion in rustdoc.
r? types
for small rustc_driver programs, most of their imports will currently be related to diagnostics. this change simplifiers their code so it's more clear what in the driver is modified from the default.
this is especially important for external drivers which are out of tree and not updated in response to breaking changes. for these drivers, each import is a liability for future code, since it can be broken when refactors happen.
here is an example driver which is simplified by these changes:
```
diff --git a/src/main.rs b/src/main.rs
index f81aa3e..11e5f18 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -1,16 +1,8 @@
#![feature(rustc_private)]
extern crate rustc_driver;
extern crate rustc_interface;
-extern crate rustc_errors;
-extern crate rustc_session;
use rustc_driver::Callbacks;
-use rustc_errors::{emitter::HumanReadableErrorType, ColorConfig};
use rustc_interface::interface;
-use rustc_session::config::ErrorOutputType;
-use rustc_session::EarlyDiagCtxt;
struct DisableSafetyChecks;
@@ -26,11 +18,7 @@ fn main() {
"https://github.com/jyn514/jyn514.github.io/issues/new",
|_| (),
);
- let handler = EarlyDiagCtxt::new(ErrorOutputType::HumanReadable(
- HumanReadableErrorType::Default,
- ColorConfig::Auto,
- ));
- rustc_driver::init_rustc_env_logger(&handler);
+ rustc_driver::init_rustc_env_logger(&Default::default());
std::process::exit(rustc_driver::catch_with_exit_code(move || {
let args: Vec<String> = std::env::args().collect();
rustc_driver::RunCompiler::new(&args, &mut DisableSafetyChecks).run()
```
The `Borrowed` variant is no longer used. This commit removes it, along
with the `as_results_cursor` method that produces it, and renames
`as_results_cursor_mut` as `as_results_cursor`.
As of #133155 `Formatter:new` uses `as_results_cursor` to create a
non-mutable results reference, and then later that is accessed via
`deref_mut` which results in a runtime abort. Changing to
`as_results_cursor_mut` fixes it.
Fixes#133641.
Remove `hir::ArrayLen`
This refactoring removes `hir::ArrayLen`, replacing it with `hir::ConstArg`. To represent inferred array lengths (previously `hir::ArrayLen::Infer`), a new variant `ConstArgKind::Infer` is added.
r? `@BoxyUwU`
coverage: Use a query to identify which counter/expression IDs are used
Given that we already have a query to identify the highest-numbered counter ID in a MIR body, we can extend that query to also build bitsets of used counter/expression IDs. That lets us avoid some messy coverage bookkeeping during the main MIR traversal for codegen.
This does mean that we fail to treat some IDs as used in certain MIR-inlining scenarios, but I think that's fine, because it means that the results will be consistent across all instantiations of a function.
---
There's some more cleanup I want to do in the function coverage collector, since it isn't really collecting anything any more, but I'll leave that for future work.
Only error raw lifetime followed by `\'` in edition 2021+
Fixes#133479
cc #132341
I think this fixes a purely theoretical regression since it only affects edition 2015 (who is using that?) and only in the very rare case of a raw lifetime followed immediately by a lifetime like `'r#a'r`.
Make `adjust_fulfillment_errors` work with `HostEffectPredicate` and `const_conditions`
Greatly improves the spans for reporting unsatisfied `~const` bounds :)
r? project-const-traits or maybe ``@lcnr`` (if you want to deal with a diagnostics PR lmao)
Properly pass linker arguments that contain commas
When linking with the system C compiler, we sometimes want to forward certain arguments unchanged to the linker. This can be done with `-Wl,arg1,arg2` or `-Xlinker arg1 -Xlinker arg2`. `-Wl` is used when possible, since it is more compact, but it does not support commas in the argument itself - in those cases, we need to use `-Xlinker`, and that is what this PR implements.
This also fixes using sanitizers on macOS with `-Clinker-flavor=ld`, as those were previously manually using `-Wl`/`-Xlinker` (probably since the support wasn't present in the `link_args` function).
Note that there has been [a previous PR for this](https://github.com/rust-lang/rust/pull/38798), but it only implemented this in certain cases when passing `-rpath`.
r? compiler
Rollup of 8 pull requests
Successful merges:
- #128184 (std: refactor `pthread`-based synchronization)
- #132047 (Robustify and genericize return-type-notation resolution in `resolve_bound_vars`)
- #133515 (fix: hurd build, stat64.st_fsid was renamed to st_dev)
- #133602 (fix: fix codeblocks in `PathBuf` example)
- #133622 (update link to "C++ Exceptions under the hood" blog)
- #133660 (Do not create trait object type if missing associated types)
- #133686 (Add diagnostic item for `std::ops::ControlFlow`)
- #133689 (Fixed typos by changing `happend` to `happened`)
r? `@ghost`
`@rustbot` modify labels: rollup
Add diagnostic item for `std::ops::ControlFlow`
This will be used in Clippy to detect useless conversions done through `ControlFlow::map_break()` and `ControlFlow::map_continue()`.
Robustify and genericize return-type-notation resolution in `resolve_bound_vars`
#129629 implemented return-type-notation (RTN) in its path form, like `where T::method(..): Bound`. As part of lowering, we must record the late-bound vars for the where clause introduced by the method (namely, its early- and late-bound lifetime arguments, since `where T::method(..)` turns into a higher-ranked where clause over all of the lifetimes according to [RFC 3654](https://rust-lang.github.io/rfcs/3654-return-type-notation.html#converting-to-higher-ranked-trait-bounds)).
However, this logic was only looking at the where clauses of the parent item that the `T::method(..)` bound was written on, and not any parent items. This PR generalizes that logic to look at the parent item (i.e. the outer impl or trait) instead and fixes a (debug only) assertion as an effect.
This logic is also more general and likely easier to adapt to more interesting (though likely very far off) cases like non-lifetime binder `for<T: Trait> T::method(..): Send` bounds.
Tracking:
- https://github.com/rust-lang/rust/issues/109417
Respect verify-llvm-ir option in the backend
We are currently unconditionally verifying the LLVM IR in the backend (twice), ignoring the value of the verify-llvm-ir option. This has substantial compile-time impact for debug builds.
Make `compare_impl_item` into a query
Turns `compare_impl_item` into a query (generalizing the existing query for `compare_impl_const`), and uses that in `Instance::resolve` to fail resolution when an implementation is incompatible with the trait it comes from.
Fixes#119701Fixes#121127Fixes#121411Fixes#129075Fixes#129127Fixes#129214Fixes#131294
Eliminate print_expr_maybe_paren function from pretty printers
This PR is part of backporting Syn's expression precedence design into rustc. (See #133603 for other work on this.)
In Syn, our version of `print_expr_cond_paren` is called `print_subexpression` and it is called from 19 places. Of those calls, 12 of them need a "custom" behavior for the `needs_paren` argument, whereas only 7 use a "standard" behavior resembling `print_subexpression($e, $e.precedence() < Precedence::$Variant, ...)`. In other words the behavior that rustc_ast_pretty's `print_expr_maybe_paren` implements is actually not what you want most of the time. The current usage you see in rustc is overuse.
<details>
<summary>Aside: am I confident about the correctness of Syn's parenthesization? Yes. Click for details.</summary>
---
The behavior is constrained by the following pair of tests which both run over every Rust source file of rustc and the standard library and tools and test suites:
- To rule out **false positives**: for every expression in every source file, print the expression, parse it back, and verify that not a single new parenthesis got added. Since these are expressions parsed from source code, not macro-generated syntax trees, we know they must never need automatic parenthesis insertion. Rustc's pretty printer does not pass this.
Pseudocode: `assert(expr == parse(print(expr)))`
- To rule out **false negatives**: for every expression in every source file, replace every Expr::Paren node in the syntax tree with just its contents, i.e. stripping the parentheses but otherwise preserving the syntax tree structure. Then print the stripped expression performing parenthesis insertion wherever needed, and reparse it. Verify that the reparsed expression has identical structure to the original, despite there being no parentheses in the original prior to printing, i.e. all the right parentheses got re-inserted by the printer to preserve the expression's structure. Rustc's pretty printer does not pass this. See https://github.com/dtolnay/syn/pull/1788 which reveals multiple rustc_ast_pretty bugs.
Pseudocode: `assert(unparenthesize(expr) == unparenthesize(parse(print(unparenthesize(expr)))))`
---
</details>
If `print_expr_maybe_paren` is usually not correct, is there harm in keeping it for the minority of cases where it is correct? I think the answer is yes and Syn doesn't use any equivalent of this helper function. The problems with it are:
- Having both `print_expr_maybe_paren` and `print_expr_cond_paren` applies counterproductive inertia against moving from the first to the second. When looking at a call site like `print_expr_maybe_paren(e, Precedence::$Variant, ...)` with parentheses not being inserted where they should be, anyone's first inclination would be to solve the bug by tweaking $Variant because that is the only knob that visibly appears in the function call. For example to pass "prec + 1", like tweaking the code to conditionally pass `Precedence::Prefix` instead of `Precedence::Cast`.
Experience in Syn shows this is (almost?) never what you want the person to do. In a call `print_expr_cond_paren(e, e.precedence() < ExprPrecedence::$Variant, ...)` almost always the best fix involves one of:
- Changing `e.precedence()`, e.g. to `fixup.leading_precedence(e)` and `fixup.trailing_precedence(e)` in cases of asymmetrical precedence (`(return 1) + 1` vs `1 + return 1`).
- Changing `<` to `<=`, to handle associativity and other grammar restrictions like chained comparisons (which rustc gets wrong today).
- Adding `||` and/or `&&` clauses to the condition.
By using these 3 better knobs instead of $Variant, it upholds the property that any time we talk about precedence, it is always the precedence of some actual expression that our code is actively manipulating, instead of a value standing in for some imaginary precedence level that would exist between two consecutive [real levels](https://doc.rust-lang.org/1.83.0/reference/expressions.html#expression-precedence). For example consider that "`Cast` + 1" might be `Prefix` today, but only until some new Rust syntax ends up adding a level between those.
- The `print_expr_maybe_paren` call sites look shorter, but they are not clearer. For myself, a function argument that says "does this subexpression need parenthesization" is a concrete thing that is easy to think about, while a function argument that is "what is the effective precedence level associated with this subexpression's placement inside its parent expression" is abstract and tricky to even state a precise meaning for. I expect that for someone less familiar with the pretty printer working on adding a new expression kind (like postfix match, recently), having every subexpression consistently printed using `print_expr_cond_paren` will be more beneficial, for the same reason, than having `print_expr_maybe_paren` available.
r? ``@lcnr``
Mark visionOS as supporting `std`
Cargo's -Zbuild-std has recently started checking this field, which causes it to fail to compile even though we have full support for the standard library on these targets.
[Example of failed build](https://github.com/rust-random/getrandom/actions/runs/12069033154/job/33655430622).
Affected targets: `aarch64-apple-visionos` and `aarch64-apple-visionos-sim`.
r? Noratrieb (because you've worked with `rustc` target metadata IIRC)
``@rustbot`` label O-visionos
use stores of the correct size to set discriminants
Resolves an old HACK /FIXME.
Note that I haven't worked much with codegen so I'm not sure if I'm using the functions correctly and I was surprised seeing out-of-range values being fed into `const_uint_big` but apparently they're wrapped implicitly? By making it explicit we can pass in-range values instead.
Support input/output in vector registers of PowerPC inline assembly
This extends currently clobber-only vector registers (`vreg`) support to allow passing `#[repr(simd)]` types as input/output.
| Architecture | Register class | Target feature | Allowed types |
| ------------ | -------------- | -------------- | -------------- |
| PowerPC | `vreg` | `altivec` | `i8x16`, `i16x8`, `i32x4`, `f32x4` |
| PowerPC | `vreg` | `vsx` | `f32`, `f64`, `i64x2`, `f64x2` |
In addition to floats and `core::simd` types listed above, `core::arch` types and custom `#[repr(simd)]` types of the same size and type are also allowed. All allowed types and relevant target features are currently unstable.
r? `@Amanieu`
`@rustbot` label +O-PowerPC +A-inline-assembly
Improve span handling in `parse_expr_bottom`.
`parse_expr_bottom` stores `this.token.span` in `lo`, but then fails to use it in many places where it could. This commit fixes that, and likewise (to a smaller extent) in `parse_ty_common`.
r? ``@spastorino``
Simplify hir_typeck_pass_to_variadic_function
r? ``@compiler-errors``
This reworks a bit how the diagnostic is generated so that it does the same as #133538
The `help` is useless now so I removed it
Add `+forced-atomics` feature to esp32s2 no_std target
Similar to https://github.com/rust-lang/rust/pull/114499 but for the Xtensa backend. The ESP32-S2 doesn't have native atomic support, but can have atomic load/stores as part of the ISA with this LLVM codegen feature.
Note: The current rev of LLVM that rustc is using doesn't contain the `+forced-atomics` feature for Xtensa, but I'm pushing this now to remove the patch from our fork in `esp-rs/rust`.
r? ``@Amanieu`` because you reviewed the related RISC-V PR
Fix target_feature handling in freg of LoongArch inline assembly
In LoongArch inline assembly, freg currently always accepts f32/f64 as input/output.
9b4d7c6a40/compiler/rustc_target/src/asm/loongarch.rs (L41)
However, these types actually require f/d target features as in RISC-V.
Otherwise, an (ugly) compile error will occur: https://godbolt.org/z/K61Gq1E9E
f32/f64 without f:
```
error: couldn't allocate output register for constraint '{$f1}'
--> <source>:12:11
|
12 | asm!("", in("$f1") x, lateout("$f1") y);
| ^
```
f64 with f but without d:
```
error: scalar-to-vector conversion failed, possible invalid constraint for vector type
--> <source>:19:11
|
19 | asm!("", in("$f1") x, lateout("$f1") y);
| ^
```
cc ``@heiher``
r? ``@Amanieu``
``@rustbot`` label +O-LoongArch +A-inline-assembly
Do not call `extern_crate` on current trait on crate mismatch errors
When we encounter an error caused by traits/types of different versions of the same crate, filter out the current crate when collecting spans to add to the context so we don't call `extern_crate` on the `DefId` of the current crate, which is meaningless and ICEs.
Produced output with this filter:
```
error[E0277]: the trait bound `foo::Struct: Trait` is not satisfied
--> y.rs:13:19
|
13 | check_trait::<foo::Struct>();
| ^^^^^^^^^^^ the trait `Trait` is not implemented for `foo::Struct`
|
note: there are multiple different versions of crate `foo` in the dependency graph
--> y.rs:7:1
|
4 | extern crate foo;
| ----------------- one version of crate `foo` is used here, as a direct dependency of the current crate
5 |
6 | pub struct Struct;
| ----------------- this type implements the required trait
7 | pub trait Trait {}
| ^^^^^^^^^^^^^^^ this is the required trait
|
::: x.rs:4:1
|
4 | pub struct Struct;
| ----------------- this type doesn't implement the required trait
5 | pub trait Trait {}
| --------------- this is the found trait
= note: two types coming from two different versions of the same crate are different types even if they look the same
= help: you can use `cargo tree` to explore your dependency tree
note: required by a bound in `check_trait`
--> y.rs:10:19
|
10 | fn check_trait<T: Trait>() {}
| ^^^^^ required by this bound in `check_trait`
```
Fix#133563.
[AIX] handle libunwind native_libs
AIX should follow a similar path here to other libunwind platforms, with regards to system vs in-tree libunwind and the native lib search directories.
Having the right native lib search directories here is also required to get the correct default library search paths, due to some quirks of the AIX linker.
Stabilize `extended_varargs_abi_support`
I think that is everything? If there is any documentation regarding `extern` and/or varargs to correct, let me know, some quick greps suggest that there might be none.
Tracking issue: https://github.com/rust-lang/rust/issues/100189
Bump boostrap compiler to new beta
Currently failing due to something about the const stability checks and `panic!`. I'm not sure why though since I wasn't able to see any PRs merged in the past few days that would result in a `cfg(bootstrap)` that shouldn't be removed. cc `@RalfJung` #131349
Support `clobber_abi` in AVR inline assembly
This PR implements the `clobber_abi` part necessary to eventually stabilize the inline assembly for AVR. This is tracked in #93335.
This is heavily inspired by the sibling-PR #131310 for the MSP430. I've explained my reasoning in the first commit message in detail, which is reproduced below for easier reviewing:
This follows the [ABI documentation] of AVR-GCC:
> The [...] call-clobbered general purpose registers (GPRs) are registers that might be destroyed (clobbered) by a function call.
>
> - **R18–R27, R30, R31**
>
> These GPRs are call clobbered. An ordinary function may use them without restoring the contents. [...]
>
> - **R0, T-Flag**
>
> The temporary register and the T-flag in SREG are also call-clobbered, but this knowledge is not exposed explicitly to the compiler (R0 is a fixed register).
Therefore this commit lists the aforementioned registers `r18–r27`, `r30` and `r31` as clobbered registers. Since the `r0` register (listed above as well) is not available in inline assembly at all (potentially because the AVR-GCC considers it a fixed register causing the register to never be used in register allocation and LLVM adopting this), there is no need to list it in the clobber list (the `r0`-variant is not even available). A comment was added to ensure, that the `r0` gets added to the clobber-list once the register gets usable in inline ASM.
Since the SREG is normally considered clobbered anyways (unless the user supplies the `preserve_flags`-option), there is no need to explicitly list a bit in this register (which is not possible to list anyways).
Note, that this commit completely ignores the case of interrupts (that are described in the ABI-specification), since every register touched in an ISR need to be saved anyways.
[ABI documentation]: https://gcc.gnu.org/wiki/avr-gcc#Call-Used_Registers
r? ``@Amanieu``
``@rustbot`` label +O-AVR
This is currently handled automatically by the fact that codegen doesn't visit
coverage statements in unused functions, but that will no longer be the case
when unused IDs are identified by a separate query instead.
Rollup of 7 pull requests
Successful merges:
- #132782 (improvements on initial sysroot and libdir finding logics)
- #133466 (Fix typos in pin.rs)
- #133492 (bootstrap: allow skipping steps with start of path)
- #133501 (support revealing defined opaque post borrowck)
- #133530 (Use consistent wording in docs, use is zero instead of is 0)
- #133538 (Better diagnostic for fn items in variadic functions)
- #133590 (Rename `-Zparse-only`)
r? `@ghost`
`@rustbot` modify labels: rollup
support revealing defined opaque post borrowck
By adding a new `TypingMode::PostBorrowckAnalysis`. Currently only supported with the new solver and I didn't look into the way we replace `ReErased`. ``@compiler-errors`` mentioned that always using existentials may be unsound.
r? ``@compiler-errors``
Remove `HybridBitSet`
`HybridBitSet` was introduced under the name `HybridIdxSetBuf` way back in #53383 where it was a big win for NLL borrow checker performance. In #93984 the more flexible `ChunkedBitSet` was added. Uses of `HybridBitSet` have gradually disappeared (e.g. #116152) and there are now few enough that they can be replaced with `BitSet` or `ChunkedBitSet`, and `HybridBitSet` can be removed, cutting more than 700 lines of code.
r? `@Mark-Simulacrum`
As part of the larger goal of reducing `HybridBitSet` use in general.
This code is for debugging only and isn't performance sensitive, so
`ChunkedBitSet` should be fine.
The current implementation is slow because it does an operation for
every bit in the set, even zero bits. So if you have a large bitset with
many zero bits (which is common) it's very slow.
This commit improves the iterator to skip over `Zeros` chunks in a
single step, and uses the fast `BitIter` for `Mixed` chunks. It also
removes the existing `fold` implementation, which was only there because
the old iterator was slow.
- Fix a typo in a comment.
- Remove unnecessary `Chunk::` qualifiers.
- Rename `ChunkedBitIter::bitset` as `ChunkedBitIter::bit_set`, because
`bit_set` is the form used everywhere else.
- Avoid some unnecessary local variables.
`ChunkedBitSet::is_empty` currently does an unnecessary check. This
commit removes that check and adds clarifying comments and an assertion
that demonstrate why it's unnecessary.
Revert #133418 (Store coverage source regions as `Span`) due to regression #133606
This reverts commit adf9b5fcd1, reversing changes made to af1ca153d4.
Reverting #133418 due to regressions reported at #133606.
r? jieyouxu
this implements checks necessary to guarantee that we can actually
perform a tail call. while extremely restrictive, this is what is
documented in the RFC, and all these checks are needed for one reason or
another.
ensure JSON-defined targets are consistent
We have a `check_consistency` check that ensures some invariants which (presumably) the rest of the compiler relies on. However, JSON targets can easily be written in a way that violates those invariants. So this PR applies the same consistency check to JSON targets that we already enforce for built-in targets.
I have converted many of the assertions in that function to new macros that show a nice error instead of a panic; if people are okay with the general approach here, I can do that for the rest of the checks as well.
Enable -Zshare-generics for inline(never) functions
This avoids inlining cross-crate generic items when possible that are
already marked inline(never), implying that the author is not intending
for the function to be inlined by callers. As such, having a local copy
may make it easier for LLVM to optimize but mostly just adds to binary
bloat and codegen time. In practice our benchmarks indicate this is
indeed a win for larger compilations, where the extra cost in dynamic
linking to these symbols is diminished compared to the advantages in
fewer copies that need optimizing in each binary.
It might also make sense it expand this with other heuristics (e.g.,
`#[cold]`) in the future, but this seems like a good starting point.
FWIW, I expect that doing cleanup in where we make the decision
what should/shouldn't be shared is also a good idea. Way too
much code needed to be tweaked to check this. But I'm hoping
to leave that for a follow-up PR rather than blocking this on it.
this is funny though! apparently tidy parsed `.gitignore`, but did not
recognize unignore lines (`!...`), so tidy was ignoring `rustc_mir_build`
this whole time (at least for some lints?).
I was surprised to find that running with `-Zparse-only` only parses the
crate root file. Other files aren't parsed because that happens later
during expansion.
This commit renames the option and updates the help message to make this
clearer.
This reduces code sizes and better respects programmer intent when
marking inline(never). Previously such a marking was essentially ignored
for generic functions, as we'd still inline them in remote crates.
When we encounter an error caused by traits/types of different versions of the same crate, filter out the current crate when collecting spans to add to the context so we don't call `extern_crate` on the `DefId` of the current crate, which is meaningless and ICEs.
Produced output with this filter:
```
error[E0277]: the trait bound `foo::Struct: Trait` is not satisfied
--> y.rs:13:19
|
13 | check_trait::<foo::Struct>();
| ^^^^^^^^^^^ the trait `Trait` is not implemented for `foo::Struct`
|
note: there are multiple different versions of crate `foo` in the dependency graph
--> y.rs:7:1
|
4 | extern crate foo;
| ----------------- one version of crate `foo` is used here, as a direct dependency of the current crate
5 |
6 | pub struct Struct;
| ----------------- this type implements the required trait
7 | pub trait Trait {}
| ^^^^^^^^^^^^^^^ this is the required trait
|
::: x.rs:4:1
|
4 | pub struct Struct;
| ----------------- this type doesn't implement the required trait
5 | pub trait Trait {}
| --------------- this is the found trait
= note: two types coming from two different versions of the same crate are different types even if they look the same
= help: you can use `cargo tree` to explore your dependency tree
note: required by a bound in `check_trait`
--> y.rs:10:19
|
10 | fn check_trait<T: Trait>() {}
| ^^^^^ required by this bound in `check_trait`
```
Fix#133563.
always create `DefId`s for anon consts
but don't use them anywhere, we intentionally don't encode them in the crate metadata.
best reviewed by disabling whitespace.
This pretty much reimplements #133285 while adding the tests of #133455. Fixes#133064
r? `@BoxyUwU` `@compiler-errors`
This commit adds the relevant registers to the list of clobbered regis-
ters (part of #93335). This follows the [ABI documentation] of AVR-GCC:
> The [...] call-clobbered general purpose registers (GPRs) are
> registers that might be destroyed (clobbered) by a function call.
>
> - **R18–R27, R30, R31**
>
> These GPRs are call clobbered. An ordinary function may use them
> without restoring the contents. [...]
>
> - **R0, T-Flag**
>
> The temporary register and the T-flag in SREG are also call-
> clobbered, but this knowledge is not exposed explicitly to the
> compiler (R0 is a fixed register).
Therefore this commit lists the aforementioned registers `r18–r27`,
`r30` and `r31` as clobbered registers. Since the `r0` register (listed
above as well) is not available in inline assembly at all (potentially
because the AVR-GCC considers it a fixed register causing the register
to never be used in register allocation and LLVM adopting this), there
is no need to list it in the clobber list (the `r0`-variant is not even
available). A comment was added to ensure, that the `r0` gets added to
the clobber-list once the register gets usable in inline ASM.
Since the SREG is normally considered clobbered anyways (unless the user
supplies the `preserve_flags`-option), there is no need to explicitly
list a bit in this register (which is not possible to list anyways).
Note, that this commit completely ignores the case of interrupts (that
are described in the ABI-specification), since every register touched in
an ISR need to be saved anyways.
[ABI documentation]: https://gcc.gnu.org/wiki/avr-gcc#Call-Used_Registers
Cargo's -Zbuild-std has recently started checking this field, which
causes it to fail to compile even though we have full support for the
standard library on these targets.
Small doc fixes in `rustc_codegen_ssa`
I'm trying to make a toy codegen backend for `rustc`, and I got confused for a few minutes about what `codegen_backend` was referring to in the `CodegenBackend::join_codegen` docs.
Experimentally, it looks like the result of `CodegenBackend::codegen_crate` is passed to `CodegenBackend::join_codegen`, so this updates the docs to refer to that. This time using intra-doc links to hopefully cause people to notice if that gets out of date again.
Also, added another intra-doc link nearby, on `CodegenBackend::link`, for the same reason.
Fix clobber_abi in RV32E and RV64E inline assembly
Currently clobber_abi in RV32E and RV64E inline assembly is implemented using InlineAsmClobberAbi::RiscV, but broken since x16-x31 cannot be used in RV32E and RV64E.
```
error: cannot use register `x16`: register can't be used with the `e` target feature
--> <source>:42:14
|
42 | asm!("", clobber_abi("C"), options(nostack, nomem, preserves_flags));
| ^^^^^^^^^^^^^^^^
error: cannot use register `x17`: register can't be used with the `e` target feature
--> <source>:42:14
|
42 | asm!("", clobber_abi("C"), options(nostack, nomem, preserves_flags));
| ^^^^^^^^^^^^^^^^
error: cannot use register `x28`: register can't be used with the `e` target feature
--> <source>:42:14
|
42 | asm!("", clobber_abi("C"), options(nostack, nomem, preserves_flags));
| ^^^^^^^^^^^^^^^^
error: cannot use register `x29`: register can't be used with the `e` target feature
--> <source>:42:14
|
42 | asm!("", clobber_abi("C"), options(nostack, nomem, preserves_flags));
| ^^^^^^^^^^^^^^^^
error: cannot use register `x30`: register can't be used with the `e` target feature
--> <source>:42:14
|
42 | asm!("", clobber_abi("C"), options(nostack, nomem, preserves_flags));
| ^^^^^^^^^^^^^^^^
error: cannot use register `x31`: register can't be used with the `e` target feature
--> <source>:42:14
|
42 | asm!("", clobber_abi("C"), options(nostack, nomem, preserves_flags));
| ^^^^^^^^^^^^^^^^
```
r? `@Amanieu`
`@rustbot` label O-riscv +A-inline-assembly
Don't type error if we fail to coerce `Pin<T>` because it doesnt contain a ref
Fixes https://github.com/rust-lang/rust/issues/133222. Also moves some tests into a directory for better bookkeeping.
r? eholk or re-roll
`parse_expr_bottom` stores `this.token.span` in `lo`, but then fails to
use it in many places where it could. This commit fixes that, and
likewise (to a smaller extent) in `parse_ty_common`.
Rollup of 12 pull requests
Successful merges:
- #129409 (Expand std::os::unix::fs::chown() doc with a warning)
- #133320 (Add release notes for Rust 1.83.0)
- #133368 (Delay a bug when encountering an impl with unconstrained generics in `codegen_select`)
- #133428 (Actually use placeholder regions for trait method late bound regions in `collect_return_position_impl_trait_in_trait_tys`)
- #133512 (Add `as_array` and `as_mut_array` conversion methods to slices.)
- #133519 (Check `xform_ret_ty` for WF in the new solver to improve method winnowing)
- #133520 (Structurally resolve before applying projection in borrowck)
- #133534 (extend group-forbid-always-trumps-cli test)
- #133537 ([rustdoc] Fix new clippy lints)
- #133543 ([AIX] create shim for lgammaf_r)
- #133547 (rustc_span: Replace a `HashMap<_, ()>` with `HashSet`)
- #133550 (print generated doc paths)
r? `@ghost`
`@rustbot` modify labels: rollup
Structurally resolve before applying projection in borrowck
As far as I can tell, all other `.normalize` calls in borrowck are noops and can remain that way. This is the only one that actually requires structurally resolving the type.
r? lcnr
Check `xform_ret_ty` for WF in the new solver to improve method winnowing
This is a bit interesting. Method probing in the old solver is stronger than the new solver because eagerly normalizing types causes us to check their corresponding trait goals. This is important because we don't end up checking all of the where clauses of a method when method probing; just the where clauses of the impl. i.e., for:
```
impl Foo
where
WC1,
{
fn method()
where
WC2,
{}
}
```
We only check WC1 and not WC2. This is because at this point in probing the method is instantiated w/ infer vars, and checking the where clauses in WC2 will lead to cycles if we were to check them (at least that's my understanding; I could investigate changing that in general, incl. in the old solver, but I don't have much confidence that it won't lead to really bad overflows.)
This PR chooses to emulate the old solver by just checking that the return type is WF. This is theoretically stronger, but I'm not too worried about it. I think we alternatively have several approaches we can take here, though this one seems the simplest. Thoughts?
r? lcnr
Actually use placeholder regions for trait method late bound regions in `collect_return_position_impl_trait_in_trait_tys`
So in https://github.com/rust-lang/rust/pull/113182, I introduced a "diagnostics improvement" in the form of 473c88dfb6, which changes which signature we end up instantiating with placeholder regions and which signature we end up instantiating with fresh region vars so that we have placeholders corresponding to the names of the late-bound regions coming from the *impl*.
However, this is not sound, since now we're essentially no longer proving that *all* instantiations of the trait method are compatible with an instantiation of the impl method, but vice versa (which is weaker). Let's look at the example `tests/ui/impl-trait/in-trait/do-not-imply-from-trait-impl.rs`:
```rust
trait MkStatic {
fn mk_static(self) -> &'static str;
}
impl MkStatic for &'static str {
fn mk_static(self) -> &'static str { self }
}
trait Foo {
fn foo<'a: 'static, 'late>(&'late self) -> impl MkStatic;
}
impl Foo for str {
fn foo<'a: 'static>(&'a self) -> impl MkStatic + 'static {
self
}
}
fn call_foo<T: Foo + ?Sized>(t: &T) -> &'static str {
t.foo().mk_static()
}
fn main() {
let s = call_foo(String::from("hello, world").as_str());
println!("> {s}");
}
```
To collect RPITITs, we were previously instantiating the trait signature with infer vars (`fn(&'?0 str) -> ?1t` where `?1t` is the variable we use to infer the RPITIT) and the impl signature with placeholders (there are no late-bound regions in that signature, so we just have `fn(&'a str) -> Opaque`).
Equating the signatures works, since all we do is unify `?1t` with `Opaque` and `'?0` with `'a`. However, conceptually it *shouldn't* hold, since this definition is not valid for *all* instantiations of the trait method but just the one where `'0` (i.e. `'late`) is equal to `'a` :(
## So what
This PR effectively reverts 473c88dfb6 to fix the unsoundness.
Fixes#133427
Also fixes#133425, which is actually coincidentally another instance of this bug (but not one that is weaponized into UB, just one that causes an ICE in refinement checking).
Delay a bug when encountering an impl with unconstrained generics in `codegen_select`
Despite its name, `codegen_select` is what powers `Instance::try_resolve`, which is used in pre-codegen contexts to try to resolve a method where possible. One place that it's used is in the "recursion MIR lint" that detects recursive MIR bodies.
If we encounter an impl in `codegen_select` that contains unconstrained generic parameters, we expect that impl to caused an error to be reported; however, there's no temporal guarantee that this error is reported *before* we call `codegen_select`. This is what a delayed bug is *for*, and this PR makes us use a delayed bug rather than asserting something about errors already having been emitted.
Fixes #126646
Rollup of 5 pull requests
Successful merges:
- #132410 (Some more refactorings towards removing driver queries)
- #133418 (coverage: Store coverage source regions as `Span` until codegen)
- #133498 (Add missing code examples on `LocalKey`)
- #133518 (Structurally resolve before checking `!` in HIR typeck)
- #133521 (Structurally resolve before matching on type of projection)
r? `@ghost`
`@rustbot` modify labels: rollup
Structurally resolve before matching on type of projection
Another missing structural resolve in closure upvar analysis. I think it's better to place the normalization here rather than trying to guarantee that all types returned by the expr use visitor are structurally normalized, which I don't think we do now. Thoughts?
r? lcnr
coverage: Store coverage source regions as `Span` until codegen
Historically, coverage spans were converted into line/column coordinates during the MIR instrumentation pass.
This PR moves that conversion step into codegen, so that coverage spans spend most of their time stored as `Span` instead.
In addition to being conceptually nicer, this also reduces the size of coverage mappings in MIR, because `Span` is smaller than 4x u32.
---
There should be no changes to coverage output.
Some more refactorings towards removing driver queries
Follow up to https://github.com/rust-lang/rust/pull/127184
## Custom driver breaking change
The `after_analysis` callback is changed to accept `TyCtxt` instead of `Queries`. The only safe query in `Queries` to call at this point is `global_ctxt()` which allows you to enter the `TyCtxt` either way. To fix your custom driver, replace the `queries: &'tcx Queries<'tcx>` argument with `tcx: TyCtxt<'tcx>` and remove your `queries.global_ctxt().unwrap().enter(|tcx| { ... })` call and only keep the contents of the closure.
## Custom driver deprecation
The `after_crate_root_parsing` callback is now deprecated. Several custom drivers are incorrectly calling `queries.global_ctxt()` from inside of it, which causes some driver code to be skipped. As such I would like to either remove it in the future or if custom drivers still need it, change it to accept an `&rustc_ast::Crate` instead.
Recover some lost performence from #132732
This PR reorders some conditions in the `dangling_pointers_from_temporaries` lint to avoid some potentially expensive query call, in particular those who could involve some metadata decoding from disk.
cc https://github.com/rust-lang/rust/pull/132732#issuecomment-2499990683
cc `@Kobzol`
Some minor dyn-related tweaks
Each commit should be self-explanatory, but I'm happy to explain what's going on if not. These are tweaks I pulled out of #133388, but they can be reviewed sooner than that.
r? types
Allow injecting a profiler runtime into `#![no_core]` crates
An alternative to #133300, allowing `-Cinstrument-coverage` to be used with `-Zbuild-std`.
The incompatibility between `profiler_builtins` and `#![no_core]` crates appears to have been caused by profiler_builtins depending on core, and therefore conflicting with core (or minicore).
But that's a false dependency, because the profiler doesn't contain any actual Rust code. So we can just mark the profiler itself as `#![no_core]`, and remove the incompatibility error.
---
For context, the error was originally added by #79958.
do not constrain infer vars in `find_best_leaf_obligation`
This ended up causing an ICE by making the following code path reachable by incorrectly constraining an inference variable while computing the best obligation for a preceding ambiguity. Closes#129444.
f2abf827c1/compiler/rustc_trait_selection/src/solve/fulfill.rs (L312-L314)
I have to be honest, I don't fully understand how that change removes all the additional diagnostics :3
r? `@compiler-errors`
Use edition of `macro_rules` when compiling the macro
This changes the edition assigned to a macro_rules macro when it is compiled to use the edition of where the macro came from instead of the local crate's edition.
This fixes a problem when a macro_rules macro is created by a proc-macro. Previously that macro would be tagged with the local edition, which would cause problems with using the correct edition behavior inside the macro. For example, the check for unsafe attributes would cause errors in 2024 when using proc-macros from older editions.
This is partially related to https://github.com/rust-lang/rust/issues/132906. Unfortunately this is only a half fix for that issue. It fixes the error that happens in 2024, but does not fix the lint firing in 2021. I'm still trying to think of some way to fix that, but I'm running low on ideas.
Revert diagnostics hack to fix ICE 132920
This reverts 8a568d9f15 from #128849 to fix the diagnostics ICE in #132920.
The hack mentioned in that commit was supposed to be tailored to E277, but that codepath is used actually shared with other errors, e.g. at least the E283 from the linked issue.
We may have to eat the slightly worse diagnostics until a non-hacky way to make this error less verbose is implemented (or I guess a different hack specializing even more to E277's structure).
Sorry ``@estebank`` 🙏. I can close this if you'd prefer to fix it in a different way.
Since it seems unexpected that #128849 would impact the repro, here's how the error used to look before that PR.
```console
warning: unused import: `minirapier::Ray`
--> src/main.rs:2:5
|
2 | use minirapier::Ray;
| ^^^^^^^^^^^^^^^
|
= note: `#[warn(unused_imports)]` on by default
error[E0283]: type annotations needed
--> src/main.rs:10:5
|
10 | insert_resource(Res.into());
| ^^^^^^^^^^^^^^^ ---------- type must be known at this point
| |
| cannot infer type of the type parameter `R` declared on the function `insert_resource`
|
= note: cannot satisfy `_: Resource`
= help: the trait `Resource` is implemented for `Res`
note: required by a bound in `insert_resource`
--> src/main.rs:4:23
|
4 | fn insert_resource<R: Resource>(_resource: R) {}
| ^^^^^^^^ required by this bound in `insert_resource`
help: consider specifying the generic argument
|
10 | insert_resource::<R>(Res.into());
| +++++
help: consider removing this method call, as the receiver has type `Res` and `Res: Resource` trivially holds
|
10 - insert_resource(Res.into());
10 + insert_resource(Res);
```
And how it looks now without the ICE.
```console
warning: unused import: `minirapier::Ray`
--> src/main.rs:2:5
|
2 | use minirapier::Ray;
| ^^^^^^^^^^^^^^^
|
= note: `#[warn(unused_imports)]` on by default
error[E0283]: type annotations needed
--> src/main.rs:10:5
|
10 | insert_resource(Res.into());
| ^^^^^^^^^^^^^^^ ---------- type must be known at this point
| |
| cannot infer type of the type parameter `R` declared on the function `insert_resource`
|
= note: cannot satisfy `_: Resource`
note: there are multiple different versions of crate `minibevy` in the dependency graph
--> /home/lqd/rust/tmp/minimization/issue-132920/rustc-ice-version-conflict/minibevy_b/src/lib.rs:1:1
|
1 | pub trait Resource {}
| ^^^^^^^^^^^^^^^^^^ this is the required trait
|
::: src/main.rs:1:5
|
1 | use minibevy::Resource;
| -------- one version of crate `minibevy` is used here, as a direct dependency of the current crate
2 | use minirapier::Ray;
| ---------- one version of crate `minibevy` is used here, as a dependency of crate `minirapier`
|
::: /home/lqd/rust/tmp/minimization/issue-132920/rustc-ice-version-conflict/minibevy_a/src/lib.rs:1:1
|
1 | pub trait Resource {}
| ------------------ this is the found trait
= help: you can use `cargo tree` to explore your dependency tree
note: required by a bound in `insert_resource`
--> src/main.rs:4:23
|
4 | fn insert_resource<R: Resource>(_resource: R) {}
| ^^^^^^^^ required by this bound in `insert_resource`
help: consider specifying the generic argument
|
10 | insert_resource::<R>(Res.into());
| +++++
help: consider removing this method call, as the receiver has type `Res` and `Res: Resource` trivially holds
|
10 - insert_resource(Res.into());
10 + insert_resource(Res);
|
```
The improvements from #128849 are still present and the note about the trait coming from the 2 versions of bevy is more explanatory/helpful than before, albeit a bit verbosely.
Fixes#132920.
Remove -Zfuel.
I'm not sure this feature is used. I only found 2 references in a google search, both referring to its introduction.
Meanwhile, it's a global mutable state, untracked by incremental compilation, so incompatible with it.
Bail on more errors in dyn ty lowering
If we have more than one principal trait, or if we have a principal trait with errors in it, then bail with `TyKind::Error` rather than attempting lowering. Lowering a dyn trait with more than one principal just arbitrarily chooses the first one and drops the subsequent ones, and lowering a dyn trait path with errors in it is just kinda useless.
This suppresses unnecessary errors which I think is net-good, but also is important to make sure that we don't end up leaking `{type error}` in https://github.com/rust-lang/rust/issues/133388 error messaging :)
r? types
Simplify array length mismatch error reporting (to not try to turn consts into target usizes)
This changes `TypeError::FixedArrayLen` to use `ExpectedFound<ty::Const<'tcx>>` (instead of `ExpectedFound<u64>`), and renames it to `TypeError::ArrayLen`. This allows us to avoid a `try_to_target_usize` call in the type relation, which ICEs when we have a scalar of the wrong bit length (i.e. u8).
This also makes `structurally_relate_tys` to always use this type error kind any time we have a const mismatch resulting from relating the array-len part of `[T; N]`.
This has the effect of changing the error message we issue for array length mismatches involving non-valtree consts. I actually quite like the change, though, since before:
```
LL | fn test<const N: usize, const M: usize>() -> [u8; M] {
| ------- expected `[u8; M]` because of return type
LL | [0; N]
| ^^^^^^ expected `M`, found `N`
|
= note: expected array `[u8; M]`
found array `[u8; N]`
```
and after, which I think is far less verbose:
```
LL | fn test<const N: usize, const M: usize>() -> [u8; M] {
| ------- expected `[u8; M]` because of return type
LL | [0; N]
| ^^^^^^ expected an array with a size of M, found one with a size of N
```
The only questions I have are:
1. Should we do something about backticks here? Right now we don't backtick either fully evaluated consts like `2`, or rigid consts like `Foo::BAR`.... but maybe we should? It seems kinda verbose to do for numbers -- maybe we could intercept those specifically.
2. I guess we may still run the risk of leaking unevaluated consts into error reporting like `2 + 1`...?
r? ``@BoxyUwU``
Fixes#126359Fixes#131101
No need to re-sort existential preds in relate impl
We already assert that these predicates are in the right ordering in `mk_poly_existential_predicates`.
r? types
Remove the `DefinitelyInitializedPlaces` analysis.
Its only use is in the `tests/ui/mir-dataflow/def_inits-1.rs` where it is tested via `rustc_peek_definite_init`.
Also, it's probably buggy. It's supposed to be the inverse of `MaybeUninitializedPlaces`, and it mostly is, except that `apply_terminator_effect` is a little different, and `apply_switch_int_edge_effects` is missing. Unlike `MaybeUninitializedPlaces`, which is used extensively in borrow checking, any bugs in `DefinitelyInitializedPlaces` are easy to overlook because it is only used in one small test.
This commit removes the analysis. It also removes
`rustc_peek_definite_init`, `Dual` and `MeetSemiLattice`, all of which are no longer needed.
r? ``@cjgillot``
Inline ExprPrecedence::order into Expr::precedence
The representation of expression precedence in rustc_ast has been an obstacle to further improvements in the pretty-printer (continuing from #119105 and #119427).
Previously the operation of *"does this expression have lower precedence than that one"* (relevant for parenthesis insertion in macro-generated syntax trees) consisted of 3 steps:
1. Convert `Expr` to `ExprPrecedence` using `.precedence()`
2. Convert `ExprPrecedence` to `i8` using `.order()`
3. Compare using `<`
As far as I can guess, the reason for the separation between `precedence()` and `order()` was so that both `rustc_ast::Expr` and `rustc_hir::Expr` could convert as straightforwardly as possible to the same `ExprPrecedence` enum, and then the more finicky logic performed by `order` could be present just once.
The mapping between `Expr` and `ExprPrecedence` was intended to be as straightforward as possible:
```rust
match self.kind {
ExprKind::Closure(..) => ExprPrecedence::Closure,
...
}
```
although there were exceptions of both many-to-one, and one-to-many:
```rust
ExprKind::Underscore => ExprPrecedence::Path,
ExprKind::Path(..) => ExprPrecedence::Path,
...
ExprKind::Match(_, _, MatchKind::Prefix) => ExprPrecedence::Match,
ExprKind::Match(_, _, MatchKind::Postfix) => ExprPrecedence::PostfixMatch,
```
Where the nature of `ExprPrecedence` becomes problematic is when a single expression kind might be associated with multiple different precedence levels depending on context (outside the expression) and contents (inside the expression). For example consider what is the precedence of an ExprKind::Closure `$closure`. Well, on the left-hand side of a binary operator it would need parentheses in order to avoid the trailing binary operator being absorbed into the closure body: `($closure) + Rhs`, so the precedence is something lower than that of `+`. But on the right-hand side of a binary operator, a closure is just a straightforward prefix expression like a unary op, which is a relatively high precedence level, higher than binops but lower than method calls: `Lhs + $closure` is fine without parens but `($closure).method()` needs them. But as a third case, if the closure contains an explicit return type, then the precedence is an even higher level than that, never needing parenthesization even in a binop left-hand side or method call: `|| -> bool { false } + Rhs` or `|| -> bool { false }.method()`.
You can see that trying to capture all of this resolution about expressions into `ExprPrecedence` violates the intention of `ExprPrecedence` being a straightforward one-to-one correspondence from each AST and HIR `ExprKind` variant. It would be possible to attempt that by doing stuff like `ExprPrecedence::Closure(Side::Leading, ReturnType::No)`, but I don't foresee the original envisioned benefit of the `precedence()`/`order()` distinction being retained in this approach. Instead I want to move toward a model that Syn has been using successfully. In Syn, there is a Precedence enum but it differs from rustc in the following ways:
- There are [relatively few variants](https://github.com/dtolnay/syn/blob/2.0.87/src/precedence.rs#L11-L47) compared to rustc's `ExprPrecedence`. For example there is no distinction at the precedence level between returns and closures, or between loops and method calls.
- We distinguish between [leading](https://github.com/dtolnay/syn/blob/2.0.87/src/fixup.rs#L293) and [trailing](https://github.com/dtolnay/syn/blob/2.0.87/src/fixup.rs#L309) precedence, taking into account an expression's context such as what token follows it (for various syntactic bail-outs in Rust's grammar, like ambiguities around break-with-value) and how it relates to operators from the surrounding syntax tree.
- There are no hardcoded mysterious integer quantities like rustc's `PREC_CLOSURE = -40`. All precedence comparisons are performed via PartialOrd on a C-like enum.
This PR is just a first step in these changes. As you can tell from Syn, I definitely think there is value in having a dedicated type to represent precedence, instead of what `order()` is doing with `i8`. But that is a whole separate adventure because rustc_ast doesn't even agree consistently on `i8` being the type for precedence order; `AssocOp::precedence` instead uses `usize` and there are casts in both directions. It is likely that a type called `ExprPrecedence` will re-appear, but it will look substantially different from the one that existed before this PR.
Use ReadCache for archive reading in bootstrap
Address expensive archive reading in bootstrap. This fixes https://github.com/rust-lang/rust/issues/133268
Enable the `std` feature of `object` to use `ReadCache` instead of reading the entire archive file into memory to check for headers. This takes minimal extra time to compile compared to introducing other expensive dependencies to `bootstrap`.
r? jieyouxu
Tweak parameter mismatch explanation to not say `{unknown}`
* Tweak parameter mismatch explanation not to call parameters with no identifier `{unknown}`
* Say "both" when there are two parameters
* Backtick a type parameter name for consistency
the emscripten OS no longer exists on non-wasm targets
https://github.com/rust-lang/rust/pull/117338 removed our asmjs targets, which AFAIK means that emscripten only exists on wasm targets. However at least one place in the code still checked "is wasm or is emscripten". Let's fix that.
Cc ```@workingjubilee```
Refactor `where` predicates, and reserve for attributes support
Refactor `WherePredicate` to `WherePredicateKind`, and reserve for attributes support in `where` predicates.
This is a part of #115590 and is split from #132388.
r? petrochenkov
`ResultsCursor` currently owns its `Results`. But sometimes the
`Results` is needed again afterwards. So there is
`ResultsCursor::into_results` for extracting the `Results`, which leads
to some awkwardness.
This commit adds `ResultsHandle`, a `Cow`-like type that can either
borrow or own a a `Results`. `ResultsCursor` now uses it. This is good
because some `ResultsCursor`s really want to own their `Results`, while
others just want to borrow it.
We end with with a few more lines of code, but get some nice cleanups.
- `ResultsCursor::into_results` and `Formatter::into_results` are
removed.
- `write_graphviz_results` now just borrows a `Results`, instead of the
awkward "take ownership of a `Results` and then return it unchanged"
pattern.
This reinstates the cursor flexibility that was lost in #118230 -- which
removed the old `ResultsRefCursor` and `ResultsCloneCursor` types -- but
in a much simpler way. Hooray!
In `MaybeRequiresStorage::apply_before_statement_effect`, call
`transfer_function` directly, as is already done in
`MaybeRequiresStorage::apply_before_terminator_effect`. This makes it clear
that the operation doesn't rely on the `MaybeBorrowedLocals` results.
Support input/output in vector registers of s390x inline assembly (under asm_experimental_reg feature)
This extends currently clobber-only vector registers (`vreg`) support to allow passing `#[repr(simd)]` types, floats (f32/f64/f128), and integers (i32/i64/i128) as input/output.
This is unstable and gated under new `#![feature(asm_experimental_reg)]` (tracking issue: https://github.com/rust-lang/rust/issues/133416). If the feature is not enabled, only clober is supported as before.
| Architecture | Register class | Target feature | Allowed types |
| ------------ | -------------- | -------------- | -------------- |
| s390x | `vreg` | `vector` | `i32`, `f32`, `i64`, `f64`, `i128`, `f128`, `i8x16`, `i16x8`, `i32x4`, `i64x2`, `f32x4`, `f64x2` |
This matches the list of types that are supported by the vector registers in LLVM:
https://github.com/llvm/llvm-project/blob/llvmorg-19.1.0/llvm/lib/Target/SystemZ/SystemZRegisterInfo.td#L301-L313
In addition to `core::simd` types and floats listed above, custom `#[repr(simd)]` types of the same size and type are also allowed. All allowed types other than i32/f32/i64/f64/i128, and relevant target features are currently unstable.
Currently there is no SIMD type for s390x in `core::arch`, but this is tracked in https://github.com/rust-lang/rust/issues/130869.
cc https://github.com/rust-lang/rust/issues/130869 about vector facility support in s390x
cc https://github.com/rust-lang/rust/issues/125398 & https://github.com/rust-lang/rust/issues/116909 about f128 support in asm
`@rustbot` label +O-SystemZ +A-inline-assembly
Fix asm goto with outputs and move it to a separate feature gate
Tracking issue: #119364
This PR addresses 3 aspects of asm goto with outputs:
* Codegen is fixed. My initial implementation has an oversight which cause the output to be only stored in fallthrough path, but not in label blocks.
* Outputs can now be used with `options(noreturn)` if a label block is given.
* All of this is moved to a new feature gate, because we likely want to stabilise `asm_goto` before asm goto with outputs.
`@rustbot` labels: +A-inline-assembly +F-asm
There is a not-very-useful layering in the lexer, where
`TokenTreesReader` contains a `StringReader`. This commit combines them
and names the result `Lexer`, which is a more obvious name for it.
The methods of `Lexer` are now split across `mod.rs` and `tokentrees.rs`
which isn't ideal, but it doesn't seem worth moving a bunch of code to
avoid it.
add a test for target-feature-ABI warnings in closures and when calling extern fn
Also update the comment regarding the inheritance of target features into closures, to make it more clear that we really shouldn't do this right now.
only store valid proc macro item for doc link
Fixes#132743
The definition item can be detected if it is exported in the doc, so store these items rather than skipping.
r? `@petrochenkov`
When labels are present, the `noreturn` option really means that asm block
won't fallthrough -- if labels are present, then outputs can still be
meaningfully used.
A used function with no mappings has historically indicated a bug, but that
will no longer be the case after moving some fallible span-processing steps
into codegen.
Rollup of 6 pull requests
Successful merges:
- #133300 (inject_panic_runtime(): Avoid double negation for 'any non rlib')
- #133301 (Add code example for `wrapping_neg` method for signed integers)
- #133371 (remove is_trivially_const_drop)
- #133389 (Stabilize `const_float_methods`)
- #133398 (rustdoc: do not call to_string, it's already impl Display)
- #133405 (tidy: Distinguish between two different meanings of "style file")
r? `@ghost`
`@rustbot` modify labels: rollup
inject_panic_runtime(): Avoid double negation for 'any non rlib'
<details>
<summary>This PR originally did more things .Click to expand to see.</summary>
By not trying to inject a profiler runtime when only building an rlib. This logic already exists for the panic runtime.
This makes
RUSTFLAGS="-Cinstrument-coverage" cargo build -Zbuild-std=std,profiler_builtins
work. Note that you probably also need
`RUST_COMPILER_RT_FOR_PROFILER=$src/llvm-project/compiler-rt` in your environment.
cc #79401
# Demonstration
Before this fix you get these errors:
```console
$ rm -rf target ; RUST_COMPILER_RT_FOR_PROFILER=/home/martin/src/llvm-project/compiler-rt RUSTFLAGS="-Cinstrument-coverage" cargo +nightly build --release -Zbuild-std=std,profiler_builtins
error: `profiler_builtins` crate (required by compiler options) is not compatible with crate attribute `#![no_core]`
error[E0152]: found duplicate lang item `manually_drop`
= note: first definition in `core` loaded from /home/martin/.rustup/toolchains/nightly-x86_64-unknown-linux-gnu/lib/rustlib/x86_64-unknown-linux-gnu/lib/libcore-d453bab70303062c.rlib
= note: second definition in the local crate (`core`)
```
With the fix the build succeeds:
```console
$ rm -rf target ; RUST_COMPILER_RT_FOR_PROFILER=/home/martin/src/llvm-project/compiler-rt RUSTFLAGS="-Cinstrument-coverage" cargo +stage1 build --release -Zbuild-std=std,profiler_builtins
Finished `release` profile [optimized] target(s) in 45.57s
```
And we can check code coverage. My example program looks like this:
```rs
fn main() {
if std::env::args_os().nth(1) == Some("write-file".into()) {
std::fs::write("hello.txt", "Hello, world!").unwrap();
} else {
println!("Hello, world!");
}
}
```
when the program prints to stdout:
```
$ LLVM_PROFILE_FILE=stdout.profraw ./target/release/hello-world
Hello, world!
```
we can see that `fs::write()` is not being used (note the `0`'s):
```console
$ /home/martin/src/rust/build/x86_64-unknown-linux-gnu/stage1/lib/rustlib/x86_64-unknown-linux-gnu/bin/llvm-profdata merge -sparse stdout.profraw -o stdout.profdata
$ /home/martin/src/rust/build/x86_64-unknown-linux-gnu/stage1/lib/rustlib/x86_64-unknown-linux-gnu/bin/llvm-cov show target/release/hello-world --sources /home/martin/src/rust/build/x86_64-unknown-linux-gnu/stage1/lib/rustlib/src/rust/library/std/src/fs.rs --instr-profile stdout.profdata --color | grep -A 3 'pub fn write(&mut self, write: b
ool) -> &mut Self {'
1357| 0| pub fn write(&mut self, write: bool) -> &mut Self {
1358| 0| self.0.write(write);
1359| 0| self
1360| 0| }
```
but when we print to a file:
```console
$ LLVM_PROFILE_FILE=file.profraw ./target/release/hello-world write-file
```
the code coverage shows `fs::write()` as being used (note the `1`'s):
```console
$ /home/martin/src/rust/build/x86_64-unknown-linux-gnu/stage1/lib/rustlib/x86_64-unknown-linux-gnu/bin/llvm-profdata merge -sparse file.profraw -o file.profdata
$ /home/martin/src/rust/build/x86_64-unknown-linux-gnu/stage1/lib/rustlib/x86_64-unknown-linux-gnu/bin/llvm-cov show target/release/hello-world --sources /home/martin/src/rust/build/x86_64-unknown-linux-gnu/stage1/lib/rustlib/src/rust/library/std/src/fs.rs --instr-profile file.profdata --color | grep -A 3 'pub fn write(&mut self, write: bool) -> &mut Self {'
1357| 1| pub fn write(&mut self, write: bool) -> &mut Self {
1358| 1| self.0.write(write);
1359| 1| self
1360| 1| }
```
</summary>
rustc: Fail fast when compiling a source file larger than 4 GiB
Currently if you try to compile a file that is larger than 4 GiB, `rustc` will first read the whole into memory before failing.
If we can read the metadata of the file, we can fail before reading the file.
Using `cc_args` panics when using `-Clinker-flavor=ld`, because the
arguments are in a form tailored for `-Clinker-flavor=gcc`.
So instead, we use `link_args` and let that wrap the arguments with the
appropriate `-Wl` or `-Xlinker` when needed.
Update TRPL to add new Chapter 17: Async and Await
- Add support to `rustbook` to pass through the `-L`/`--library-path` flag to `mdbook` so that references to the `trpl` crate
- Build the `trpl` crate as part of the book tests. Make it straightforward to add other such book dependencies in the future if needed by implementing that in a fairly general way.
- Update the submodule for the book to pull in the new chapter on async and await, as well as a number of other fixes. This will happen organically/automatically in a week, too, but this lets me group this change with the next one:
- Update the compiler messages which reference the existing chapters 17–20, which are now chapters 18-21. There are only two, both previously referencing chapter 18.
- Update the UI tests which reference the compiler message outputs.
finish `Reveal` removal
After #133212 changed the `TypingMode` to be the only source of truth, this entirely rips out `Reveal`.
cc #132279
r? `@compiler-errors`
However, don't change the behavior of any existing targets at this time.
For targets that used the old default, explicitly set `crt_static_default = true`.
This makes it easier for new targets to use the correct defaults while
leaving the changing of individual targets to future PRs.
Related to https://github.com/rust-lang/compiler-team/issues/422
With the insertion of a new chapter 17 on async and await to _The Rust
Programming Language_, references in compiler output to later chapters
need to be updated to avoid confusing users. Redirects exist so that
users who click old links will end up in the right place anyway, but
this way users will be directed to the right URL in the first place.
show abi_unsupported_vector_types lint in future breakage reports
The lint is now riding the train to 1.84. Given that crater found no case of this lint triggering at all, IMO it's fine to make it "report in deps" already for 1.85.
Part of https://github.com/rust-lang/rust/issues/116558.
Minimally constify `Add`
* This PR removes the requirement for `impl const` to have a const stability attribute. cc ``@RalfJung`` I believe you mentioned that it would make much more sense to require `const_trait`s to have const stability instead. I agree with that sentiment but I don't think that is _required_ for a small scale experimentation like this PR. https://github.com/rust-lang/project-const-traits/issues/16 should definitely be prioritized in the future, but removing the impl check should be good for now as all callers need `const_trait_impl` enabled for any const impl to work.
* This PR is intentionally minimal as constifying other traits can become more complicated (`PartialEq`, for example, would run into requiring implementing it for `str` as that is used in matches, which runs into the implementation for slice equality which uses specialization)
Per the reasons above, anyone who is interested in making traits `const` in the standard library are **strongly encouraged** to reach out to us on the [Zulip channel](https://rust-lang.zulipchat.com/#narrow/channel/419616-t-compiler.2Fproject-const-traits) before proceeding with the work.
cc ``@rust-lang/project-const-traits``
I believe there is prior approval from libs that we can experiment, so
r? project-const-traits
[AIX] Add option -X32_64 to the "strip" command
The AIX `strip` utility requires option `-X` to specify the object mode. This patch adds the `-X32_64` option to the `strip` command so that it can handle both 32-bit and 64-bit objects. The parameter `option` of function `strip_symbols_with_external_utility`, previously a single string, has been changed to `options`, an array of string slices, to accommodate multiple `strip` options.
Re-delay a resolve `bug` related to `Self`-ctor in patterns
For the code pattern reported in <https://github.com/rust-lang/rust/issues/133272>,
```rs
impl Foo {
fn fun() {
let S { ref Self } = todo!();
}
}
```
<https://github.com/rust-lang/rust/pull/121208> converted this to a `span_bug` from a `span_delayed_bug` because this specific self-ctor code pattern lacked test coverage. It turns out this can be hit but we just lacked test coverage, so change it back to a `span_delayed_bug` and add a targeted test case.
Follow-up to #121208, cc ``@nnethercote`` (very good exercise to expose our test coverage gaps).
Fixes#133272.
Allow disabling ASan instrumentation for globals
AddressSanitizer adds instrumentation to global variables unless the [`no_sanitize_address`](https://llvm.org/docs/LangRef.html#global-attributes) attribute is set on them.
This commit extends the existing `#[no_sanitize(address)]` attribute to set this; previously it only had the desired effect on functions.
(cc https://github.com/rust-lang/rust/issues/39699)
Rollup of 8 pull requests
Successful merges:
- #132090 (Stop being so bail-y in candidate assembly)
- #132658 (Detect const in pattern with typo)
- #132911 (Pretty print async fn sugar in opaques and trait bounds)
- #133102 (aarch64 softfloat target: always pass floats in int registers)
- #133159 (Don't allow `-Zunstable-options` to take a value )
- #133208 (generate-copyright: Now generates a library file too.)
- #133215 (Fix missing submodule in `./x vendor`)
- #133264 (implement OsString::truncate)
r? `@ghost`
`@rustbot` modify labels: rollup
Don't allow `-Zunstable-options` to take a value
Passing an explicit boolean value (`-Zunstable-options=on`, `off` etc.) sometimes appears to work, but actually puts the compiler into an unintended state where unstable _options_ are still forbidden, but unstable values of _some_ stable options are allowed.
This is a result of `-Zunstable-options` being checked in multiple different places, in slightly different ways. Fixing the checks in `config::nightly_options` to understand boolean values would be non-trivial, so for now it's easier to make things consistent by forbidding values in the `-Z` parser.
---
There were a few uses of this in tests, which happened to work because they were tests of unstable values.
aarch64 softfloat target: always pass floats in int registers
This is a part of https://github.com/rust-lang/rust/issues/131058: on softfloat aarch64 targets, the float registers may be unavailable. And yet, LLVM will happily use them to pass float types if the corresponding target features are enabled. That's a problem as it means enabling/disabling `neon` instructions can change the ABI.
Other targets have a `soft-float` target feature that forces the use of the soft-float ABI no matter whether float registers are enabled or not; aarch64 has nothing like that.
So we follow the aarch64 [softfloat ABI](https://github.com/rust-lang/rust/issues/131058#issuecomment-2385027423) and treat floats like integers for `extern "C"` functions. For the "Rust" ABI, we do the same for scalars, and then just do something reasonable for ScalarPair that avoids the pointer indirection.
Cc ```@workingjubilee```
Detect const in pattern with typo
When writing a constant name incorrectly in a pattern, the pattern will be identified as a new binding. We look for consts in the current crate, consts that where imported in the current crate and for local `let` bindings in case someone got them confused with `const`s.
```
error: unreachable pattern
--> $DIR/const-with-typo-in-pattern-binding.rs:30:9
|
LL | GOOOD => {}
| ----- matches any value
LL |
LL | _ => {}
| ^ no value can reach this
|
help: you might have meant to pattern match against the value of similarly named constant `GOOD` instead of introducing a new catch-all binding
|
LL | GOOD => {}
| ~~~~
```
Fix#132582.
Stop being so bail-y in candidate assembly
A conceptual follow-up to #132084. We gotta stop bailing so much when there are errors; it's both unnecessary, leads to weird knock-on errors, and it's messing up the vibes lol
Implement `~const Destruct` effect goal in the new solver
This also fixed a subtle bug/limitation of the `NeedsConstDrop` check. Specifically, the "`Qualif`" API basically treats const drops as totally structural, even though dropping something that has an explicit `Drop` implementation cannot be structurally decomposed. For example:
```rust
#![feature(const_trait_impl)]
#[const_trait] trait Foo {
fn foo();
}
struct Conditional<T: Foo>(T);
impl Foo for () {
fn foo() {
println!("uh oh");
}
}
impl<T> const Drop for Conditional<T> where T: ~const Foo {
fn drop(&mut self) {
T::foo();
}
}
const FOO: () = {
let _ = Conditional(());
//~^ This should error.
};
fn main() {}
```
In this example, when checking if the `Conditional(())` rvalue is const-drop, since `Conditional` has a const destructor, we would previously recurse into the `()` value and determine it has nothing to drop, which means that it is considered to *not* need a const drop -- even though dropping `Conditional(())` would mean evaluating the destructor which relies on that `T: const Foo` bound to hold!
This could be fixed alternatively by banning any const conditions on `const Drop` impls, but that really sucks -- that means that basically no *interesting* const drop impls could be written. We have the capability to totally and intuitively support the right behavior, which I've implemented here.
Stabilize the 2024 edition
This stabilizes the 2024 edition for Rust 1.85, scheduled to be released on February 20, 2025. 🎉
cc tracking issue: https://github.com/rust-lang/rust/issues/117258
There is a fair amount of follow-up work after this that I am working on (various docs, cargo, rustfmt, etc.), and this is will unblock those other changes.
The deployment target environment variable is OS-specific, and if you're
in a place where you're asking `rustc` for the deployment target, you're
likely to also wanna know the environment variable.
Rollup of 8 pull requests
Successful merges:
- #133238 (re-export `is_loongarch_feature_detected`)
- #133288 (Support `each_ref` and `each_mut` in `[T; N]` in constant expressions.)
- #133311 (Miri subtree update)
- #133313 (Use arc4random of libc for RTEMS target)
- #133319 (Simplify `fulfill_implication`)
- #133323 (Bail in effects in old solver if self ty is ty var)
- #133330 (library: update comment around close())
- #133337 (Fix typo in `std:🧵:Scope::spawn` documentation.)
r? `@ghost`
`@rustbot` modify labels: rollup
Bail in effects in old solver if self ty is ty var
Otherwise when we try to check something like `?t: ~const Trait` we'll immediately stick it to the first param-env candidate, lol.
r? lcnr
Its only use is in the `tests/ui/mir-dataflow/def_inits-1.rs` where it
is tested via `rustc_peek_definite_init`.
Also, it's probably buggy. It's supposed to be the inverse of
`MaybeUninitializedPlaces`, and it mostly is, except that
`apply_terminator_effect` is a little different, and
`apply_switch_int_edge_effects` is missing. Unlike
`MaybeUninitializedPlaces`, which is used extensively in borrow
checking, any bugs in `DefinitelyInitializedPlaces` are easy to overlook
because it is only used in one small test.
This commit removes the analysis. It also removes
`rustc_peek_definite_init`, `Dual` and `MeetSemiLattice`, all of which
are no longer needed.
[AIX] change system dynamic library format
Historically on AIX, almost all dynamic libraries are distributed in `.a` Big Archive Format which can consists of both static and shared objects in the same archive (e.g. `libc++abi.a(libc++abi.so.1)`). During the initial porting process, the dynamic libraries are kept as `.a` to simplify the migration, but semantically having an XCOFF object under the archive extension is wrong. For crate type `cdylib` we want to be able to distribute the libraries as archives as well.
We are migrating to archives with the following format:
```
$ ar -t lib<name>.a
lib<name>.so
```
where each archive contains a single member that is a shared XCOFF object that can be loaded.
Fix closure arg extraction in `extract_callable_info`, generalize it to async closures
* Fix argument extraction in `extract_callable_info`
* FIx `extract_callable_info` to work for async closures
* Remove redundant `is_fn_ty` which is just a less general `extract_callable_info`
* More precisely name what is being called (i.e. call it a "closure" not a "function")
Review this without whitespace -- I ended up reformatting `extract_callable_info` because some pesky `//` comments were keeping the let-chains from being formatted.
For the code pattern reported in
<https://github.com/rust-lang/rust/issues/133272>,
```rs
impl Foo {
fn fun() {
let S { ref Self } = todo!();
}
}
```
<https://github.com/rust-lang/rust/pull/121208> converted this to a
`span_bug` from a `span_delayed_bug` because this specific self-ctor
code pattern lacked test coverage. It turns out this can be hit but we
just lacked test coverage, so change it back to a `span_delayed_bug` and
add a target tested case.
Add visits to nodes that already have flat_maps in ast::MutVisitor
This PR aims to add `visit_` methods for every node that has a `flat_map_` in MutVisitor, giving implementers free choice over overriding `flat_map` for 1-to-n conversions or `visit` for a 1-to-1.
There is one major problem: `flat_map_stmt`.
While all other default implementations of `flat_map`s are 1-to-1 conversion, as they either only call visits or a internal 1-to-many conversions are natural, `flat_map_stmt` doesn't follow this pattern.
`flat_map_stmt`'s default implementation is a 1-to-n conversion that panics if n > 1 (effectively being a 1-to-[0;1]). This means that it cannot be used as is for a default `visit_stmt`, which would be required to be a 1-to-1.
Implementing `visit_stmt` without runtime checks would require it to reach over a potential `flat_map_item` or `filter_map_expr` overrides and call for their `visit` counterparts directly.
Other than that, if we want to keep the behavior of `flat_map_stmt` it cannot call `visit_stmt` internally.
To me, it seems reasonable to make all default implementations 1-to-1 conversions and let implementers handle `visit_stmt` if they need it, but I don't know if calling `visit` directly when a 1-to-1 is required is ok or not.
related to #128974 & #127615
r? ``@petrochenkov``
Store resolution for self and crate root module segments
Let's make sure to record the segment resolution for `self::`, `crate::` and `$crate::`.
I'm actually somewhat surprised that the only diagnostic that uses this is the one that errors on invalid generics on a module segment... but seems strictly more correct regardless, and there may be other diagnostics using these segments resolutions that just haven't been tested for `self`. Also includes a drive-by on `report_prohibit_generics_error`.
Emscripten: link with -sWASM_BIGINT
When linking an executable without dynamic linking, this is a pure improvement. It significantly reduces code size and avoids a lot of buggy behaviors. It is supported in all browsers for many years and in all maintained versions of Node.
It does change the ABI, so people who are dynamically linking with a library or executable that uses the old ABI may need to turn it off. It can be disabled if needed by passing `-Clink-arg -sWASM_BIGINT=0` to `rustc`. But few people will want to turn it off.
Note this includes a libc bump to 0.2.162!
Rollup of 6 pull requests
Successful merges:
- #129838 (uefi: process: Add args support)
- #130800 (Mark `get_mut` and `set_position` in `std::io::Cursor` as const.)
- #132708 (Point at `const` definition when used instead of a binding in a `let` statement)
- #133226 (Make `PointerLike` opt-in instead of built-in)
- #133244 (Account for `wasm32v1-none` when exporting TLS symbols)
- #133257 (Add `UnordMap::clear` method)
r? `@ghost`
`@rustbot` modify labels: rollup
I think the control flow in this function is complicated and confusing,
largely due to the use of two booleans `print_formatted` and
`fallback_to_println` that are set in multiple places and then used to
guide proceedings.
As well as hurting readability, this leads to at least one bug: if the
`write_termcolor_buf` call fails and the pager also fails, the function
will try to print color output to stdout, but that output will be empty
because `write_termcolor_buf` failed. I.e. the `if fallback_to_println`
body fails to check `print_formatted`.
This commit rewrites the function to be neater and more Rust-y, e.g. by
putting the result of `write_termcolor_buf` into an `Option` so it can
only be used on success, and by using `?` more. It also changes
terminology a little, using "pretty" to mean "formatted and colorized".
The result is a little shorter, more readable, and less buggy.
Current places where `Interpolated` is used are going to change to
instead use invisible delimiters. This prepares for that.
- It adds invisible delimiter cases to the `can_begin_*`/`may_be_*`
methods and the `failed_to_match_macro` that are equivalent to the
existing `Interpolated` cases.
- It adds panics/asserts in some places where invisible delimiters
should never occur.
- In `Parser::parse_struct_fields` it excludes an ident + invisible
delimiter from special consideration in an error message, because
that's quite different to an ident + paren/brace/bracket.
Pasted metavariables are wrapped in invisible delimiters, which
pretty-print as empty strings, and changing that can break some proc
macros. But error messages saying "expected identifer, found ``" are
bad. So this commit adds support for metavariables in `TokenDescription`
so they print as "metavariable" in error messages, instead of "``".
It's not used meaningfully yet, but will be needed to get rid of
interpolated tokens.
Account for `wasm32v1-none` when exporting TLS symbols
Exporting TLS related symbols was limited to `wasm32-unknown-unknown` because WASI and Emscripten (?) have their own infrastructure to deal with TLS. However, the introduction of `wasm32v1-none` is in the same boat as `wasm32-unknown-unknown`.
This PR adjust the mechanism to account for `wasm32v1-none` as well.
See https://github.com/rust-lang/rust/pull/102385 and https://github.com/rust-lang/rust/pull/102440.
r? ``@alexcrichton``
Make `PointerLike` opt-in instead of built-in
The `PointerLike` trait currently is a built-in trait that computes the layout of the type. This is a bit problematic, because types implement this trait automatically. Since this can be broken due to semver-compatible changes to a type's layout, this is undesirable. Also, calling `layout_of` in the trait system also causes cycles.
This PR makes the trait implemented via regular impls, and adds additional validation on top to make sure that those impls are valid. This could eventually be `derive()`d for custom smart pointers, and we can trust *that* as a semver promise rather than risking library authors accidentally breaking it.
On the other hand, we may never expose `PointerLike`, but at least now the implementation doesn't invoke `layout_of` which could cause ICEs or cause cycles.
Right now for a `PointerLike` impl to be valid, it must be an ADT that is `repr(transparent)` and the non-1zst field needs to implement `PointerLike`. There are also some primitive impls for `&T`/ `&mut T`/`*const T`/`*mut T`/`Box<T>`.
Point at `const` definition when used instead of a binding in a `let` statement
Modify `PatKind::InlineConstant` to be `ExpandedConstant` standing in not only for inline `const` blocks but also for `const` items. This allows us to track named `const`s used in patterns when the pattern is a single binding. When we detect that there is a refutable pattern involving a `const` that could have been a binding instead, we point at the `const` item, and suggest renaming. We do this for both `let` bindings and `match` expressions missing a catch-all arm if there's at least one single binding pattern referenced.
After:
```
error[E0005]: refutable pattern in local binding
--> $DIR/bad-pattern.rs:19:13
|
LL | const PAT: u32 = 0;
| -------------- missing patterns are not covered because `PAT` is interpreted as a constant pattern, not a new variable
...
LL | let PAT = v1;
| ^^^ pattern `1_u32..=u32::MAX` not covered
|
= note: `let` bindings require an "irrefutable pattern", like a `struct` or an `enum` with only one variant
= note: for more information, visit https://doc.rust-lang.org/book/ch18-02-refutability.html
= note: the matched value is of type `u32`
help: introduce a variable instead
|
LL | let PAT_var = v1;
| ~~~~~~~
```
Before:
```
error[E0005]: refutable pattern in local binding
--> $DIR/bad-pattern.rs:19:13
|
LL | let PAT = v1;
| ^^^
| |
| pattern `1_u32..=u32::MAX` not covered
| missing patterns are not covered because `PAT` is interpreted as a constant pattern, not a new variable
| help: introduce a variable instead: `PAT_var`
|
= note: `let` bindings require an "irrefutable pattern", like a `struct` or an `enum` with only one variant
= note: for more information, visit https://doc.rust-lang.org/book/ch18-02-refutability.html
= note: the matched value is of type `u32`
```
CC #132582.
Reduce false positives of tail-expr-drop-order from consumed values (attempt #2)
r? `@nikomatsakis`
Tracked by #123739.
Related to #129864 but not replacing, yet.
Related to #130836.
This is an implementation of the approach suggested in the [Zulip stream](https://rust-lang.zulipchat.com/#narrow/stream/213817-t-lang/topic/temporary.20drop.20order.20changes). A new MIR statement `BackwardsIncompatibleDrop` is added to the MIR syntax. The lint now works by inspecting possibly live move paths before at the `BackwardsIncompatibleDrop` location and the actual drop under the current edition, which should be one before Edition 2024 in practice.
When writing a constant name incorrectly in a pattern, the pattern will be identified as a new binding. We look for consts in the current crate, consts that where imported in the current crate and for local `let` bindings in case someone got them confused with `const`s.
```
error: unreachable pattern
--> $DIR/const-with-typo-in-pattern-binding.rs:30:9
|
LL | GOOOD => {}
| ----- matches any value
LL |
LL | _ => {}
| ^ no value can reach this
|
help: you might have meant to pattern match against the value of similarly named constant `GOOD` instead of introducing a new catch-all binding
|
LL | GOOD => {}
| ~~~~
```
Fix#132582.
interpret: make typing_env field private
This was made public in https://github.com/rust-lang/rust/pull/133212 but IMO it should remain private. (Specifically, this prevents it from being mutated.)
r? `@lcnr`
take 2
open up coroutines
tweak the wordings
the lint works up until 2021
We were missing one case, for ADTs, which was
causing `Result` to yield incorrect results.
only include field spans with significant types
deduplicate and eliminate field spans
switch to emit spans to impl Drops
Co-authored-by: Niko Matsakis <nikomat@amazon.com>
collect drops instead of taking liveness diff
apply some suggestions and add explantory notes
small fix on the cache
let the query recurse through coroutine
new suggestion format with extracted variable name
fine-tune the drop span and messages
bugfix on runtime borrows
tweak message wording
filter out ecosystem types earlier
apply suggestions
clippy
check lint level at session level
further restrict applicability of the lint
translate bid into nop for stable mir
detect cycle in type structure
lints_that_dont_need_to_run: never skip future-compat-reported lints
Follow-up to https://github.com/rust-lang/rust/pull/125116: future-compat lints show up with `--json=future-incompat` even if they are otherwise allowed in the crate. So let's ensure we do not skip those as part of the `lints_that_dont_need_to_run` logic.
I could not find a current future compat lint that is emitted by a lint pass, so there's no clear way to add a test for this.
Cc `@blyxyas` `@cjgillot`
Use attributes for `dangling_pointers_from_temporaries` lint
Checking for dangling pointers by function name isn't ideal, and leaves out certain pointer-returning methods that don't follow the `as_ptr` naming convention. Using an attribute for this lint cleans things up and allows more thorough coverage of other methods, such as `UnsafeCell::get()`.
Drop debug info instead of panicking if we exceed LLVM's capability to represent it
Recapping a bit of history here:
In #128861 I made debug info correctly represent parameters to inline functions by removing a fake lexical block that had been inserted to suppress LLVM assertions and by deduplicating those parameters.
LLVM, however, expects to see a single parameter _with distinct locations_, particularly distinct inlinedAt values on the DILocations. This generally worked because no matter how deep the chain of inlines it takes two different call sites in the original function to result in the same function being present multiple times, and a function call requires a non-zero number of characters, but macros threw a wrench in that in #131944. At the time I thought the issue there was limited to proc-macros, where an arbitrary amount of code can be generated at a single point in the source text.
In #132613 I added discriminators to DILocations that would otherwise be the same to repair #131944[^1]. This works, but LLVM's capacity for discriminators is not infinite (LLVM actually only allocates 12 bits for this internally). At the time I thought it would be very rare for anyone to hit the limit, but #132900 proved me wrong. In the relatively-minimized test case it also became clear to me that the issue affects regular macros too, because the call to the inlined function will (without collapse_debuginfo on the macro) be attributed to the (repeated, if the macro is used more than once) textual callsite in the macro definition.
This PR fixes the panic by dropping debug info when we exceed LLVM's maximum discriminator value. There's also a preceding commit for a related but distinct issue: macros that use collapse_debuginfo should in fact have their inlinedAts collapsed to the macro callsite and thus not need discriminators at all (and not panic/warn accordingly when the discriminator limit is exhausted).
Fixes#132900
r? `@jieyouxu`
[^1]: Editor's note: `fix` is a magic keyword in PR description that apparently will close the linked issue (it's closed already in this case, but still).
Default-enable `llvm_tools_enabled` when no `config.toml` is present
Fixes#133195. cc `@wesleywiser` could you double check if with this patch and no `config.toml` that you can run `./x test tests/ui --stage 1`?
`llvm-objcopy` is usually required by cg_ssa on macOS to workaround bad `strip`s.
cc `@bjorn3` I hope this doesn't break cg_clif...
r? bootstrap
Add `visit` methods to ast nodes that already have `walk`s on ast visitors
Some `walk` functions are called directly, because there were no correspondent visit functions.
related to #128974 & #127615
r? `@petrochenkov`
Rollup of 4 pull requests
Successful merges:
- #131081 (Use `ConstArgKind::Path` for all single-segment paths, not just params under `min_generic_const_args`)
- #132577 (Report the `unexpected_cfgs` lint in external macros)
- #133023 (Merge `-Zhir-stats` into `-Zinput-stats`)
- #133200 (ignore an occasionally-failing test in Miri)
r? `@ghost`
`@rustbot` modify labels: rollup
The maximum discriminator value LLVM can currently encode is 2^12. If macro use
results in more than 2^12 calls to the same function attributed to the same
callsite, and those calls are MIR-inlined, we will require more than the maximum
discriminator value to completely represent the debug information. Once we reach
that point drop the debug info instead.
The test relies on the fact that inlining more than 2^12 calls at the same
callsite will trigger a panic (and after the following commit, a warning) due to
LLVM limitations but with collapse_debuginfo the callsites should not be the
same.
`rustc_borrowck` cleanups, part 2
The code under `do_mir_borrowck` is pretty messy, especially the various types like `MirBorrowckCtxt`, `BorrowckInferCtxt`, `MirTypeckResults`, `MirTypeckRegionConstraints`, `CreateResult`, `TypeChecker`, `TypeVerifier`, `LivenessContext`, `LivenessResults`. This PR does some tidying up, though there's still plenty of mess left afterwards.
A sequel to #132250.
r? `@compiler-errors`
Merge `-Zhir-stats` into `-Zinput-stats`
Currently `-Z hir-stats` prints the size and count of various kinds of nodes, and the total size of all the nodes it counted, but not the total count of nodes. So, before this PR:
```
$ git clone https://github.com/BurntSushi/ripgrep
$ cd ripgrep
$ cargo +nightly rustc -- -Z hir-stats
ast-stats-1 PRE EXPANSION AST STATS
ast-stats-1 Name Accumulated Size Count Item Size
ast-stats-1 ----------------------------------------------------------------
ast-stats-1 ...
ast-stats-1 ----------------------------------------------------------------
ast-stats-1 Total 93_576
ast-stats-1
ast-stats-2 POST EXPANSION AST STATS
ast-stats-2 Name Accumulated Size Count Item Size
ast-stats-2 ----------------------------------------------------------------
ast-stats-2 ...
ast-stats-2 ----------------------------------------------------------------
ast-stats-2 Total 2_430_648
ast-stats-2
hir-stats HIR STATS
hir-stats Name Accumulated Size Count Item Size
hir-stats ----------------------------------------------------------------
hir-stats ...
hir-stats ----------------------------------------------------------------
hir-stats Total 3_678_512
hir-stats
```
For consistency, this PR adds a total for the count as well:
```
$ cargo +stage1 rustc -- -Z hir-stats
ast-stats-1 PRE EXPANSION AST STATS
ast-stats-1 Name Accumulated Size Count Item Size
ast-stats-1 ----------------------------------------------------------------
ast-stats-1 ...
ast-stats-1 ----------------------------------------------------------------
ast-stats-1 Total 93_576 1_877
ast-stats-1
ast-stats-2 POST EXPANSION AST STATS
ast-stats-2 Name Accumulated Size Count Item Size
ast-stats-2 ----------------------------------------------------------------
ast-stats-2 ...
ast-stats-2 ----------------------------------------------------------------
ast-stats-2 Total 2_430_648 48_625
ast-stats-2
hir-stats HIR STATS
hir-stats Name Accumulated Size Count Item Size
hir-stats ----------------------------------------------------------------
hir-stats ...
hir-stats ----------------------------------------------------------------
hir-stats Total 3_678_512 73_418
hir-stats
```
I wasn't sure if I was supposed to update `tests/ui/stats/hir-stats.stderr` to reflect this. I ran it locally, thinking it would fail, but it didn't:
```
$ ./x test tests/ui/stats
...
running 2 tests
i.
test result: ok. 1 passed; 0 failed; 1 ignored; 0 measured; 17949 filtered out
```
Also: is there a reason `-Z hir-stats` and `-Z input-stats` both exist? The former seems like it should completely supercede the latter. But strangely, the two give very different numbers for node counts:
```
$ cargo +nightly rustc -- -Z input-stats
...
Lines of code: 483
Pre-expansion node count: 2386
Post-expansion node count: 63844
```
That's a 30% difference in this case. Is it intentional that these numbers are so different? I see comments for both saying that they are merely approximations and should not be expected to be correct:
bd0826a452/compiler/rustc_ast_passes/src/node_count.rs (L1)bd0826a452/compiler/rustc_passes/src/hir_stats.rs (L1-L3)
Report the `unexpected_cfgs` lint in external macros
This PR marks the `unexpected_cfgs` lint as being reportable in external macros, as it's probably not the intention of the macro author to leave ineffective cfgs in the users code.
Fixes#132572
try-job: aarch64-gnu-debug
Use `ConstArgKind::Path` for all single-segment paths, not just params under `min_generic_const_args`
r? `@BoxyUwU`
edit by `@BoxyUwU:`
This PR introduces a `min_generic_const_args` feature gate and implements some preliminary work for it, representing all const arguments that are single segment paths as `ConstArg::Path` instead of only those that resolve to a const generic parameter. There are a few bits of follow up work after this lands:
- Figure out how to represent `Foo<{ STATIC }>`
- Figure out how to evaluate `Foo<{ EnumVariantConstructor }>`
- Make param env normalization handle non-anon-consts
- Move `try_from_lit` and `from_anon_const` to hir ty lowering too
It was added in #123752 to handle some cases involving emoji, but it
isn't necessary because it's always treated the same as
`TokenKind::InvalidIdent`. This commit removes it, which makes things a
little simpler.
- Rename it as `invalid_ident_or_prefix`, which matches the possible
outputs (`InvalidIdent` or `InvalidPrefix`).
- Use the local wrapper for `is_xid_continue`, for consistency.
- Make it clear what `\u{200d}` means.
Improve VecCache under parallel frontend
This replaces the single Vec allocation with a series of progressively larger buckets. With the cfg for parallel enabled but with -Zthreads=1, this looks like a slight regression in i-count and cycle counts (~1%).
With the parallel frontend at -Zthreads=4, this is an improvement (-5% wall-time from 5.788 to 5.4688 on libcore) than our current Lock-based approach, likely due to reducing the bouncing of the cache line holding the lock. At -Zthreads=32 it's a huge improvement (-46%: 8.829 -> 4.7319 seconds).
try-job: i686-gnu-nopt
try-job: dist-x86_64-linux
There is an `Rc<UniversalRegions>` within `UniversalRegionRelations`,
and yet the two types get passed around in tandem a lot.
This commit makes `UniversalRegionRelations` own `UniversalRegions`,
removing the `Rc` (which wasn't truly needed) and the tandem-passing.
This requires adding a `universal_relations` method to
`UniversalRegionRelations`, and renaming a couple of existing methods
producing iterators to avoid a name clash.
Use `TypingMode` throughout the compiler instead of `ParamEnv`
Hopefully the biggest single PR as part of https://github.com/rust-lang/types-team/issues/128.
## `infcx.typing_env` while defining opaque types
I don't know how'll be able to correctly handle opaque types when using something taking a `TypingEnv` while defining opaque types. To correctly handle the opaques we need to be able to pass in the current `opaque_type_storage` and return constraints, i.e. we need to use a proper canonical query. We should migrate all the queries used during HIR typeck and borrowck where this matters to proper canonical queries. This is
## `layout_of` and `Reveal::All`
We convert the `ParamEnv` to `Reveal::All` right at the start of the `layout_of` query, so I've changed callers of `layout_of` to already use a post analysis `TypingEnv` when encountering it.
ca87b535a0/compiler/rustc_ty_utils/src/layout.rs (L51)
## `Ty::is_[unpin|sized|whatever]`
I haven't migrated `fn is_item_raw` to use `TypingEnv`, will do so in a followup PR, this should significantly reduce the amount of `typing_env.param_env`. At some point there will probably be zero such uses as using the type system while ignoring the `typing_mode` is incorrect.
## `MirPhase` and phase-transitions
When inside of a MIR-body, we can mostly use its `MirPhase` to figure out the right `typing_mode`. This does not work during phase transitions, most notably when transitioning from `Analysis` to `Runtime`:
dae7ac133b/compiler/rustc_mir_transform/src/lib.rs (L606-L625)
All these passes still run with `MirPhase::Analysis`, but we should only use `Reveal::All` once we're run the `RevealAll` pass. This required me to manually construct the right `TypingEnv` in all these passes. Given that it feels somewhat easy to accidentally miss this going forward, I would maybe like to change `Body::phase` to an `Option` and replace it at the start of phase transitions. This then makes it clear that the MIR is currently in a weird state.
r? `@ghost`
stability: remove skip_stability_check_due_to_privacy
This was added in https://github.com/rust-lang/rust/pull/38689 to deal with https://github.com/rust-lang/rust/issues/38412. However, even after removing the check, the relevant tests still pass. Let's see if CI finds any other tests that rely on this. If not, it seems like logic elsewhere in the compiler changed so this is not required any more.
the behavior of the type system not only depends on the current
assumptions, but also the currentnphase of the compiler. This is
mostly necessary as we need to decide whether and how to reveal
opaque types. We track this via the `TypingMode`.
rename rustc_const_stable_intrinsic -> rustc_intrinsic_const_stable_indirect
In https://github.com/rust-lang/rust/pull/120370 this name caused confusion as the author thought the intrinsic was stable. So let's try a different name...
If we can land this before the beta cutoff we can avoid needing `cfg(bootstrap)` for this. ;)
Cc `@compiler-errors` `@saethlin`
Overhaul the `-l` option parser (for linking to native libs)
The current parser for `-l` options has accumulated over time, making it hard to follow. This PR tries to clean it up in several ways.
Key changes:
- This code now gets its own submodule, to slightly reduce clutter in `rustc_session::config`.
- Cleaner division between iterating over multiple `-l` options, and processing each individual one.
- Separate “split” step that breaks up the value string into `[KIND[:MODIFIERS]=]NAME[:NEW_NAME]`, but leaves parsing/validating those parts to later steps.
- This step also gets its own (disposable) unit test, to make sure it works as expected.
- A context struct reduces the burden of parameter passing, and makes it easier to write error messages that adapt to nightly/stable compilers.
- Fewer calls to `nightly_options` helper functions, because at this point we can get the same information from `UnstableOptions` and `UnstableFeatures` (which are downstream of earlier calls to those helper functions).
There should be no overall change in compiler behaviour.
Passing an explicit boolean value (`on`, `off` etc.) appears to work, but
actually puts the compiler into an unintended state where unstable _options_
are still forbidden, but unstable values of _some_ stable options are allowed.
Diagnostics for let mut in item context
The diagnostics for `let` at the top level did not account for `let mut`, which [made the error unclear](https://users.rust-lang.org/t/create-a-vector-of-constants-outside-main/121251/1).
I've made the diagnostic always display a link to valid items. I've added dedicated help for `let mut` case that suggests using a `Mutex` (to steer novice users away from the `static mut` trap). Unfortunately, neither the Rust book, nor libstd docs have dedicated section listing all other types for interior-mutable `static`s.
`suggest_borrow_generic_arg`: instantiate clauses properly
This simplifies and fixes the way `suggest_borrow_generic_arg` instantiates callees' predicates when testing them to see if a moved argument can instead be borrowed. Previously, it would ICE if the moved argument's type included a region variable, since it was getting passed to a call of `EarlyBinder::instantiate`. This makes the instantiation much more straightforward, which also fixes the ICE.
Fixes#133118
This also modifies `tests/ui/moves/moved-value-on-as-ref-arg.rs` to have more useful bounds on the tests for suggestions to borrow `Borrow` and `BorrowMut` arguments. With its old tautological `T: BorrowMut<T>` bound, this fix would make it suggest a shared borrow for that argument.
Make rustc consider itself a stable compiler when `RUSTC_BOOTSTRAP=-1`
Addresses https://github.com/rust-lang/rust/issues/123404 to allow test writers to specify `//@ rustc-env:RUSTC_BOOTSTRAP=-1` to have a given rustc consider itself a stable rustc. This is only intended for testing usages.
I did not use `RUSTC_BOOTSTRAP=0` because that can be confusing, i.e. one might think that means "not bootstrapping", but "forcing a given rustc to consider itself a stable compiler" is a different use case.
I also added a specific test to check `RUSTC_BOOTSTRAP`'s various values and how that interacts with rustc's stability story w.r.t. features and cli flags.
Noticed when trying to write a test for enabling ICE file dumping on stable.
Dunno if this needs a compiler FCP or MCP, but I can file an MCP or ask someone to start an FCP if needed. Note that `RUSTC_BOOTSTRAP` is a perma-unstable env var and has no stability guarantees (heh) whatsoever. This does not affect bootstrapping because bootstrap never sets `RUSTC_BOOTSTRAP=-1`. If someone does set that when bootstrapping, it is considered PEBKAC.
Accompanying dev-guide PR: https://github.com/rust-lang/rustc-dev-guide/pull/2136
cc `@estebank` and `@rust-lang/wg-diagnostics` for FYI
Check `use<..>` in RPITIT for refinement
`#![feature(precise_capturing_in_traits)]` allows users to write `+ use<>` bounds on RPITITs to control what lifetimes are captured by the RPITIT.
Since RPITITs currently also warn for refinement in implementations, this PR extends that refinement check for cases where we *undercapture* in an implementation, since that may be indirectly "promising" a more relaxed outlives bound than the impl author intended.
For an opaque to be refining, we need to capture *fewer* parameters than those mentioned in the captured params of the trait. For example:
```
trait TypeParam<T> {
fn test() -> impl Sized;
}
// Indirectly capturing a lifetime param through a type param substitution.
impl<'a> TypeParam<&'a ()> for i32 {
fn test() -> impl Sized + use<> {}
//~^ WARN impl trait in impl method captures fewer lifetimes than in trait
}
```
Since the opaque in the method (implicitly) captures `use<Self, T>`, and `Self = i32, T = &'a ()` in the impl, we must mention `'a` in our `use<..>` on the impl.
Tracking:
* https://github.com/rust-lang/rust/issues/130044
Fixes issue 133118.
This also modifies `tests/ui/moves/moved-value-on-as-ref-arg.rs` to have more
useful bounds on the tests for suggestions to borrow `Borrow` and `BorrowMut`
arguments. With its old tautological `T: BorrowMut<T>` bound, this fix would
make it suggest a shared borrow for that argument.
```
error[E0004]: non-exhaustive patterns: `i32::MIN..=3_i32` and `5_i32..=i32::MAX` not covered
--> $DIR/intended-binding-pattern-is-const.rs:2:11
|
LL | match 1 {
| ^ patterns `i32::MIN..=3_i32` and `5_i32..=i32::MAX` not covered
LL | x => {}
| - this pattern doesn't introduce a new catch-all binding, but rather pattern matches against the value of constant `x`
|
= note: the matched value is of type `i32`
note: constant `x` defined here
--> $DIR/intended-binding-pattern-is-const.rs:7:5
|
LL | const x: i32 = 4;
| ^^^^^^^^^^^^
help: if you meant to introduce a binding, use a different name
|
LL | x_var => {}
| ++++
help: ensure that all possible cases are being handled by adding a match arm with a wildcard pattern, a match arm with multiple or-patterns as shown, or multiple match arms
|
LL | x => {}, i32::MIN..=3_i32 | 5_i32..=i32::MAX => todo!()
| ++++++++++++++++++++++++++++++++++++++++++++++++
```
After:
```
error[E0005]: refutable pattern in local binding
--> $DIR/bad-pattern.rs:19:13
|
LL | const PAT: u32 = 0;
| -------------- missing patterns are not covered because `PAT` is interpreted as a constant pattern, not a new variable
...
LL | let PAT = v1;
| ^^^
| |
| pattern `1_u32..=u32::MAX` not covered
| help: introduce a variable instead: `PAT_var`
|
= note: `let` bindings require an "irrefutable pattern", like a `struct` or an `enum` with only one variant
= note: for more information, visit https://doc.rust-lang.org/book/ch18-02-refutability.html
= note: the matched value is of type `u32`
```
Before:
```
error[E0005]: refutable pattern in local binding
--> $DIR/bad-pattern.rs:19:13
|
LL | let PAT = v1;
| ^^^
| |
| pattern `1_u32..=u32::MAX` not covered
| missing patterns are not covered because `PAT` is interpreted as a constant pattern, not a new variable
| help: introduce a variable instead: `PAT_var`
|
= note: `let` bindings require an "irrefutable pattern", like a `struct` or an `enum` with only one variant
= note: for more information, visit https://doc.rust-lang.org/book/ch18-02-refutability.html
= note: the matched value is of type `u32`
```
Trim whitespace in RemoveLet primary span
Separate `RemoveLet` span into primary span for `let` and removal suggestion span for `let `, so that primary span does not include whitespace.
Fixes: #133031
Increase accuracy of `if` condition misparse suggestion
Fix#132656.
Look at the expression that was parsed when trying to recover from a bad `if` condition to determine what was likely intended by the user beyond "maybe this was meant to be an `else` body".
```
error: expected `{`, found `map`
--> $DIR/missing-dot-on-if-condition-expression-fixable.rs:4:30
|
LL | for _ in [1, 2, 3].iter()map(|x| x) {}
| ^^^ expected `{`
|
help: you might have meant to write a method call
|
LL | for _ in [1, 2, 3].iter().map(|x| x) {}
| +
```
If a macro statement has been parsed after `else`, suggest a missing `if`:
```
error: expected `{`, found `falsy`
--> $DIR/else-no-if.rs:47:12
|
LL | } else falsy! {} {
| ---- ^^^^^
| |
| expected an `if` or a block after this `else`
|
help: add an `if` if this is the condition of a chained `else if` statement
|
LL | } else if falsy! {} {
| ++
```
Querify MonoItem collection
Factored out of https://github.com/rust-lang/rust/pull/131650. These changes are required for post-mono MIR opts, because the previous implementation would load the MIR for every Instance that we traverse (as well as invoke queries on it). The cost of that would grow massively with post-mono MIR opts because we'll need to load new MIR for every Instance, instead of re-using the `optimized_mir` for every Instance with the same DefId.
So the approach here is to add two new queries, `items_of_instance` and `size_estimate`, which contain the specific information about an Instance's MIR that MirUsedCollector and CGU partitioning need, respectively. Caching these significantly increases the size of the query cache, but that's justified by our improved incrementality (I'm sure walking all the MIR for a huge crate scales quite poorly).
This also changes `MonoItems` into a type that will retain the traversal order (otherwise we perturb a bunch of diagnostics), and will also eliminate duplicate findings. Eliminating duplicates removes about a quarter of the query cache size growth.
The perf improvements in this PR are inflated because rustc-perf uses `-Zincremental-verify-ich`, which makes loading MIR a lot slower because MIR contains a lot of Spans and computing the stable hash of a Span is slow. And the primary goal of this PR is to load less MIR. Some squinting at `collector profile_local perf-record +stage1` runs suggests the magnitude of the improvements in this PR would be decreased by between a third and a half if that flag weren't being used. Though this effect may apply to the regressions too since most are incr-full and this change also causes such builds to encode more Spans.
Deny capturing late-bound ty/const params in nested opaques
First, this reverts a7f609504c. I can't exactly remember why I approved this specific bit of https://github.com/rust-lang/rust/pull/132466; specifically, I don't know that the purpose of that commit is, and afaict we will never have an opaque that captures late-bound params through a const because opaques can't be used inside of anon consts. Am I missing something `@cjgillot?` Since I can't see a case where this matters, and no tests seem to fail.
The second commit adds a `deny_late_regions: bool` to distinguish `Scope::LateBoundary` which should deny *any* late-bound params or just ty/consts. Then, when resolving opaques we wrap ourselves in a `Scope::LateBoundary { deny_late_regions: false }` so that we deny late-bound ty/const, which fixes a bunch of ICEs that all vaguely look like `impl for<T> Trait<Assoc = impl OtherTrait<T>>`.
I guess this could be achieved other ways; for example, with a different scope kind, or maybe we could just reuse `Scope::Opaque`. But this seems a bit more verbose. I'm open to feedback anyways.
Fixes#131535Fixes#131637Fixes#132530
I opted to remove those crashes tests ^ without adding them as regular tests, since they're basically triggering uninteresting late-bound ICEs far off in the trait solver, and the reason that existing tests such as `tests/ui/type-alias-impl-trait/non-lifetime-binder-in-constraint.rs` don't ICE are kinda just coincidental (i.e. due to a missing impl block). I don't really feel motivated to add random permutations to tests just to exercise non-lifetime binders.
r? cjgillot
Unify FnKind between AST visitors and make WalkItemKind more straight forward
Unifying `FnKind` requires a bunch of changes to `WalkItemKind::walk` signature so I'll change them in one go
related to #128974
r? `@petrochenkov`
If a macro statement has been parsed after `else`, suggest a missing `if`:
```
error: expected `{`, found `falsy`
--> $DIR/else-no-if.rs:47:12
|
LL | } else falsy! {} {
| ---- ^^^^^
| |
| expected an `if` or a block after this `else`
|
help: add an `if` if this is the condition of a chained `else if` statement
|
LL | } else if falsy! {} {
| ++
```
Look at the expression that was parsed when trying to recover from a bad `if` condition to determine what was likely intended by the user beyond "maybe this was meant to be an `else` body".
```
error: expected `{`, found `map`
--> $DIR/missing-dot-on-if-condition-expression-fixable.rs:4:30
|
LL | for _ in [1, 2, 3].iter()map(|x| x) {}
| ^^^ expected `{`
|
help: you might have meant to write a method call
|
LL | for _ in [1, 2, 3].iter().map(|x| x) {}
| +
```
This replaces the single Vec allocation with a series of progressively
larger buckets. With the cfg for parallel enabled but with -Zthreads=1,
this looks like a slight regression in i-count and cycle counts (<0.1%).
With the parallel frontend at -Zthreads=4, this is an improvement (-5%
wall-time from 5.788 to 5.4688 on libcore) than our current Lock-based
approach, likely due to reducing the bouncing of the cache line holding
the lock. At -Zthreads=32 it's a huge improvement (-46%: 8.829 -> 4.7319
seconds).
Fix span edition for 2024 RPIT coming from an external macro
This fixes a problem where code generated by an external macro with an RPIT would end up using the call-site edition instead of the macro's edition for the RPIT. When used from a 2024 crate, this caused the code to change behavior to the 2024 capturing rules, which we don't want.
This was caused by the impl-trait lowering code would replace the span with one marked with `DesugaringKind::OpaqueTy` desugaring. However, it was also overriding the edition of the span with the edition of the local crate. Instead it should be using the edition of the span itself.
Fixes https://github.com/rust-lang/rust/issues/132917
Mention both release *and* edition breakage for never type lints
This PR makes ~~two changes~~ a change to the never type lints (`dependency_on_unit_never_type_fallback` and `never_type_fallback_flowing_into_unsafe`):
1. Change the wording of the note to mention that the breaking change will be made in an edition _and_ in a future release
2. ~~Make these warnings be reported in deps (hopefully the lints are matured enough)~~
r? ``@compiler-errors``
cc ``@ehuss``
closes#132930
Rollup of 4 pull requests
Successful merges:
- #132817 (Recurse into APITs in `impl_trait_overcaptures`)
- #133021 (Refactor `configure_annotatable`)
- #133045 (tests: Test pac-ret flag merging on clang with LTO)
- #133049 (Change Visitor::visit_precise_capturing_arg so it returns a Visitor::Result)
r? `@ghost`
`@rustbot` modify labels: rollup
This fixes a problem where code generated by an external macro with an
RPIT would end up using the call-site edition instead of the macro's
edition for the RPIT. When used from a 2024 crate, this caused the code
to change behavior to the 2024 capturing rules, which we don't want.
This was caused by the impl-trait lowering code would replace the span
with one marked with `DesugaringKind::OpaqueTy` desugaring. However, it
was also overriding the edition of the span with the edition of the
local crate. Instead it should be using the edition of the span itself.
Fixes https://github.com/rust-lang/rust/issues/132917
Recurse into APITs in `impl_trait_overcaptures`
We were previously not detecting cases where an RPIT was located in the return type of an async function, leading to underfiring of the `impl_trait_overcaptures`. This PR does this recursion properly now.
cc https://github.com/rust-lang/rust/issues/132809
Separate `RemoveLet` span into primary span for `let` and removal
suggestion span for `let `, so that primary span does not include
whitespace.
Fixes: #133031
Signed-off-by: Tyrone Wu <wudevelops@gmail.com>
check_consts: fix error requesting feature gate when that gate is not actually needed
When working on https://github.com/rust-lang/hashbrown/pull/586 I noticed that the compiler asks for the `rustc_private` feature to be enabled if one forgets to set `rustc_const_stable_indirect` on a function -- but enabling `rustc_private` would not actually help. This fixes the diagnostics.
r? `@compiler-errors`
Over in Zed we've noticed that loading crates for a large-ish workspace can take almost 200ms. We've pinned it down to how rustc searches for paths, as it performs a linear search over the list of candidate paths. In our case the candidate list had about 20k entries which we had to iterate over for each dependency being loaded.
This commit introduces a simple FilesIndex that's just a sorted Vec under the hood. Since crates are looked up by both prefix and suffix, we perform a range search on said Vec (which constraints the search space based on prefix) and follow up with a linear scan of entries with matching suffixes.
FilesIndex is also pre-filtered before any queries are performed using available target information; query prefixes/sufixes are based on the target we are compiling for, so we can remove entries that can never match up front.
Overall, this commit brings down build time for us in dev scenarios by about 6%.
100ms might not seem like much, but this is a constant cost that each of our workspace crates has to pay, even when said crate is miniscule.
Rollup of 8 pull requests
Successful merges:
- #132790 (Add as_slice/into_slice for IoSlice/IoSliceMut.)
- #132905 ([AIX] Add crate "unwind" to link with libunwind)
- #132977 (Fix compilation error on Solaris due to flock usage)
- #132984 ([illumos] use pipe2 to create anonymous pipes)
- #133019 (docs: Fix missing period and colon in methods for primitive types)
- #133048 (use `&raw` in `{read, write}_unaligned` documentation)
- #133050 (Always inline functions signatures containing `f16` or `f128`)
- #133053 (tests: Fix the SIMD FFI tests with certain x86 configuration)
r? `@ghost`
`@rustbot` modify labels: rollup
Always inline functions signatures containing `f16` or `f128`
There are a handful of tier 2 and tier 3 targets that cause a LLVM crash or linker error when generating code that contains `f16` or `f128`. The cranelift backend also does not support these types. To work around this, every function in `std` or `core` that contains these types must be marked `#[inline]` in order to avoid sending any code to the backend unless specifically requested.
However, this is inconvenient and easy to forget. Introduce a check for these types in the frontend that automatically inlines any function signatures that take or return `f16` or `f128`.
Note that this is not a perfect fix because it does not account for the types being passed by reference or as members of aggregate types, but this is sufficient for what is currently needed in the standard library.
Fixes: https://github.com/rust-lang/rust/issues/133035
Closes: https://github.com/rust-lang/rust/pull/133037
There are a handful of tier 2 and tier 3 targets that cause a LLVM crash
or linker error when generating code that contains `f16` or `f128`. The
cranelift backend also does not support these types. To work around
this, every function in `std` or `core` that contains these types must
be marked `#[inline]` in order to avoid sending any code to the backend
unless specifically requested.
However, this is inconvenient and easy to forget. Introduce a check for
these types in the frontend that automatically inlines any function
signatures that take or return `f16` or `f128`.
Note that this is not a perfect fix because it does not account for the
types being passed by reference or as members of aggregate types, but
this is sufficient for what is currently needed in the standard library.
Fixes: https://github.com/rust-lang/rust/issues/133035
Closes: https://github.com/rust-lang/rust/pull/133037
Skip locking span interner for some syntax context checks
- `from_expansion` now never needs to consult the interner
- `eq_ctxt` now only needs the interner when both spans are fully interned
borrowck diagnostics: suggest borrowing function inputs in generic positions
# Summary
This generalizes borrowck's existing suggestions to borrow instead of moving when passing by-value to a function that's generic in that input. Previously, this was special-cased to `AsRef`/`Borrow`-like traits and `Fn`-like traits. This PR changes it to test if, for a moved place with type `T`, that the callee's signature and clauses don't break if you substitute in `&T` or `&mut T`. For instance, it now works with `Read`/`Write`-like traits.
Fixes https://github.com/rust-lang/rust/issues/131413
# Incidental changes
- No longer spuriously suggests mutable borrows of closures in some situations (see e.g. the tests in [tests/ui/closures/2229_closure_analysis/](https://github.com/rust-lang/rust/compare/master...dianne:rust:suggest-borrow-generic?expand=1#diff-8dfb200c559f0995d0f2ffa2f23bc6f8041b263e264e5c329a1f4171769787c0)).
- No longer suggests cloning closures that implement `Fn`, since they can be borrowed (see e.g. [tests/ui/moves/borrow-closures-instead-of-move.stderr](https://github.com/rust-lang/rust/compare/master...dianne:rust:suggest-borrow-generic?expand=1#diff-5db268aac405eec56d099a72d8b58ac46dab523cf013e29008104840168577fb)).
This keeps the behavior to suppress suggestions of `fn_once.clone()()`. I think it might make sense to suggest it with a "but this might not be your desired behavior" caveat, as is done when something is used after being consumed as the receiver for a method call. That's probably out of the scope of this PR though.
# Limitations and possible improvements
- This doesn't work for receivers of method calls. This is a small change, and I have it implemented locally, but I'm not sure it's useful on its own. In most cases I've found borrowing the receiver would change the call's output type (see below). In other cases (e.g. `Iterator::sum`), borrowing the receiver isn't useful since it's consumed.
- This doesn't work when it would change the call's output type. In general, I figure inserting references into the output type is an unwanted change. However, this also means it doesn't work in cases where the new output type would be effectively the same as the old one. For example, from the rand crate, the iterator returned by [`Rng::sample_iter`](https://docs.rs/rand/latest/rand/trait.Rng.html#method.sample_iter) is effectively the same (modulo regions) whether you borrow or consume the receiver `Rng`, so common usage involves borrowing it. I'm not sure whether the best approach is to add a more complex check of approximate equivalence, to forego checking the call's output type and give spurious suggestions, or to leave it as-is.
- This doesn't work when it would change the call's other input types. Instead, it could suggest borrowing any others that have the same parameter type (but only when suggesting shared borrows). I think this would be a pretty easy change, but I don't think it's very useful so long as the normalized output type can't change.
I'm happy to implement any of these (or other potential improvements to this), but I'm not sure which are common enough patterns to justify the added complexity. Please let me know if any sound worthwhile.
PassWrapper: disable UseOdrIndicator for Asan Win32
As described in https://reviews.llvm.org/D137227 UseOdrIndicator should be disabled on Windows since link.exe does not support duplicate weak definitions.
Fixes https://github.com/rust-lang/rust/issues/124390.
Credits also belong to `@1c3t3a` who worked with me on this.
We are currently testing this on a Windows machine.
Handle infer vars in anon consts on stable
Fixes#132955
Diagnostics will sometimes try to replace generic parameters with inference variables in failing goals. This means that if we have some failing goal with an array repeat expr count anon const in it, we will wind up with some `ty::ConstKind::Unevaluated(anon_const_def, [?x])` during diagnostics which will then ICE if we do not handle inference variables correctly on stable when normalizing type system consts.
r? ```@compiler-errors```
This subsumes the suggestions to borrow arguments with `AsRef`/`Borrow` bounds and those to borrow
arguments with `Fn` and `FnMut` bounds. It works for other traits implemented on references as well,
such as `std::io::Read`, `std::io::Write`, and `core::fmt::Write`.
Incidentally, by making the logic for suggesting borrowing closures general, this removes some
spurious suggestions to mutably borrow `FnMut` closures in assignments, as well as an unhelpful
suggestion to add a `Clone` constraint to an `impl Fn` argument.
Important: we know from the `parse_annotatable_with` call above the call
site that only some of the `Annotatable` variants are possible. The
remaining cases can be replaced with `unreachable!`.
They each have a single callsite, and the result is always unwrapped, so
the `Option<Annotatable>` return type is misleading.
Also, the comment at the `configure_annotatable` call site is wrong,
talking about a result vector, so this commit also removes that.
It was added in #115367 for anonymous ADTs. Those changes were then
reverted in #131045, but `empty_disambiguator` was left behind, perhaps
by mistake. It seems to be unnecessary.
This is setup for unifing the logic for suggestions to borrow arguments in generic positions.
As of this commit, it's still special cases for `AsRef`/`Borrow`-like traits and `Fn`-like traits.
This also downgrades its applicability to MaybeIncorrect. Its suggestion can result in ill-typed
code when the type parameter it suggests providing a different generic argument for appears
elsewhere in the callee's signature or predicates.
`resolve_ident_in_module` is a very thin wrapper around
`resolve_ident_in_module_ext`, and `resolve_ident_in_module_unadjusted`
is a very thin wrapper around `resolve_ident_in_module_unadjusted_ext`.
The wrappers make the call sites slightly more concise, but I don't
think that's worth the extra code and indirection.
This commit removes the two wrappers and removes the `_ext` suffixes
from the inner methods.
As described here UseOdrIndicator should be disabled on Windows
since link.exe does not support duplicate weak definitions
(https://reviews.llvm.org/D137227).
Co-Authored-By: Bastian Kersting <bkersting@google.com>
CFI: Append debug location to CFI blocks
Currently we're not appending debug locations to the inserted CFI blocks. This shows up in #132615 and #100783. This change fixes that by passing down the debug location to the CFI type-test generation and appending it to the blocks.
Credits also belong to `@jakos-sec` who worked with me on this.
`to_lowercase` allocates, but `eq_ignore_ascii_case` doesn't. This path
is hot enough that this makes a small but noticeable difference in
benchmarking.
clarify `must_produce_diag` ICE for debugging
We have a sanity check to ensure the expensive `trimmed_def_paths` functions are called only when producing diagnostics, and not e.g. on the happy path. The panic often happens IME during development because of randomly printing stuff, causing an ICE if no diagnostics were also emitted.
I have this change locally but figured it could be useful to others, so this PR clarifies the message when this happens during development.
The output currently looks like this by default; it's a bit confusing with words missing:
```
thread 'rustc' panicked at compiler/rustc_errors/src/lib.rs:628:17:
must_produce_diag: `trimmed_def_paths` called but no diagnostics emitted; `with_no_trimmed_paths` for debugging. called at: disabled backtrace
stack backtrace:
0: 0x7ffff79570f6 - std::backtrace_rs::backtrace::libunwind::trace::h33576c57327a3cea
at .../library/std/src/../../backtrace/src/backtrace/libunwind.rs:116:5
1: 0x7ffff79570f6 - std::backtrace_rs::backtrace::trace_unsynchronized::h7972a09393b420db
at .../library/std/src/../../backtrace/src/backtrace/mod.rs:66:5
2: 0x7ffff79570f6 - std::sys::backtrace::_print_fmt::hae8c5bbfbf7a8322
at .../library/std/src/sys/backtrace.rs:66:9
3: 0x7ffff79570f6 - <std::sys::backtrace::BacktraceLock::print::DisplayBacktrace as core::fmt::Display>::fmt::h1fd6a7a210f5b535
...
```
The new output mentions how to get more information and locate where the `with_no_trimmed_paths` call needs to be added.
1. By default, backtraces are disabled:
```
thread 'rustc' panicked at compiler/rustc_errors/src/lib.rs:642:17:
`trimmed_def_paths` called, diagnostics were expected but none were emitted. Use `with_no_trimmed_paths` for debugging. Backtraces are currently disabled: set `RUST_BACKTRACE=1` and re-run to see where it happened.
stack backtrace:
0: 0x7ffff79565f6 - std::backtrace_rs::backtrace::libunwind::trace::h33576c57327a3cea
...
```
2. With backtraces enabled:
```
thread 'rustc' panicked at compiler/rustc_errors/src/lib.rs:642:17:
`trimmed_def_paths` called, diagnostics were expected but none were emitted. Use `with_no_trimmed_paths` for debugging. This happened in the following `must_produce_diag` call's backtrace:
0: <rustc_errors::DiagCtxtHandle>::set_must_produce_diag
at .../compiler/rustc_errors/src/lib.rs:1133:58
1: <rustc_session::session::Session>::record_trimmed_def_paths
at .../compiler/rustc_session/src/session.rs:327:9
2: rustc_middle::ty::print::pretty::trimmed_def_paths
at .../compiler/rustc_middle/src/ty/print/pretty.rs:3351:5
...
```
A `\n` could be added here or there, but it didn't matter much whenever I hit this case with the new message.
Make precise capturing suggestion machine-applicable only if it has no APITs
cc https://github.com/rust-lang/rust/issues/132932
The only case where this suggestion is not machine-applicable is when we suggest turning arg-position impl trait into type parameters, which may expose type parameters that were not turbofishable before.
Proper support for cross-crate recursive const stability checks
~~Stacked on top of https://github.com/rust-lang/rust/pull/132492; only the last three commits are new.~~
In a crate without `staged_api` but with `-Zforce-unstable-if-unmarked`, we now subject all functions marked with `#[rustc_const_stable_indirect]` to recursive const stability checks. We require an opt-in so that by default, a crate can be built with `-Zforce-unstable-if-unmarked` and use nightly features as usual. This property is recorded in the crate metadata so when a `staged_api` crate calls such a function, it sees the `#[rustc_const_stable_indirect]` and allows it to be exposed on stable. This, finally, will let us expose `const fn` from hashbrown on stable.
The second commit makes const stability more like regular stability: via `check_missing_const_stability`, we ensure that all publicly reachable functions have a const stability attribute -- both in `staged_api` crates and `-Zforce-unstable-if-unmarked` crates. To achieve this, we move around the stability computation so that const stability is computed after regular stability is done. This lets us access the final result of the regular stability computation, which we use so that `const fn` can inherit the regular stability (but only if that is "unstable"). Fortunately, this lets us get rid of an `Option` in `ConstStability`.
This is the last PR that I have planned in this series.
r? `@compiler-errors`
Delete the `cfg(not(parallel))` serial compiler
Since it's inception a long time ago, the parallel compiler and its cfgs have been a maintenance burden. This was a necessary evil the allow iteration while not degrading performance because of synchronization overhead.
But this time is over. Thanks to the amazing work by the parallel working group (and the dyn sync crimes), the parallel compiler has now been fast enough to be shipped by default in nightly for quite a while now.
Stable and beta have still been on the serial compiler, because they can't use `-Zthreads` anyways.
But this is quite suboptimal:
- the maintenance burden still sucks
- we're not testing the serial compiler in nightly
Because of these reasons, it's time to end it. The serial compiler has served us well in the years since it was split from the parallel one, but it's over now.
Let the knight slay one head of the two-headed dragon!
#113349
Note that the default is still 1 thread, as more than 1 thread is still fairly broken.
cc `@onur-ozkan` to see if i did the bootstrap field removal correctly, `@SparrowLii` on the sync parts
Since it's inception a long time ago, the parallel compiler and its cfgs
have been a maintenance burden. This was a necessary evil the allow
iteration while not degrading performance because of synchronization
overhead.
But this time is over. Thanks to the amazing work by the parallel
working group (and the dyn sync crimes), the parallel compiler has now
been fast enough to be shipped by default in nightly for quite a while
now.
Stable and beta have still been on the serial compiler, because they
can't use `-Zthreads` anyways.
But this is quite suboptimal:
- the maintenance burden still sucks
- we're not testing the serial compiler in nightly
Because of these reasons, it's time to end it. The serial compiler has
served us well in the years since it was split from the parallel one,
but it's over now.
Let the knight slay one head of the two-headed dragon!
move all mono-time checks into their own folder, and their own query
The mono item collector currently also drives two mono-time checks: the lint for "large moves", and the check whether function calls are done with all the required target features.
Instead of doing this "inside" the collector, this PR refactors things so that we have a new `rustc_monomorphize::mono_checks` module providing a per-instance query that does these checks. We already have a per-instance query for the ABI checks, so this should be "free" for incremental builds. Non-incremental builds might do a bit more work now since we now have two separate MIR visits (in the collector and the mono-time checks) -- but one of them is cached in case the MIR doesn't change, which is nice.
This slightly changes behavior of the large-move check since the "move_size_spans" deduplication logic now only works per-instance, not globally across the entire collector.
Cc `@saethlin` since you're also doing some work related to queries and caching and monomorphization, though I don't know if there's any interaction here.
Make sure to ignore elided lifetimes when pointing at args for fulfillment errors
See the comment I left in the code.
---
If we have something like:
```
fn foo<'a, T: 'a + BoundThatIsNotSatisfied>() {}
```
And the user turbofishes just the type args:
```
foo::<()>();
```
Then if we try pointing at `()` (i.e. the type argument for `T`), we don't actually consider the possibility that the lifetimes may have been left out of the turbofish. We try indexing incorrectly into the HIR args, and bail on the suggestion.
Consolidate type system const evaluation under `traits::evaluate_const`
Part of #130704Fixes#128232Fixes#118545
Removes `ty::Const::{normalize_internal, eval_valtree}` and `InferCtxt::(try_)const_eval_resolve`, consolidating the associated logic into `evaluate_const` in `rustc_trait_selection`. This results in an API for `ty::Const` that is free of any normalization/evaluation functions that would be incorrect to use under `min_generic_const_args`/`associated_const_equality`/`generic_const_exprs` or, more generally, that would be incorrect to use in the presence of generic type system constants.
Moving this logic to `rustc_trait_selection` and out of `rustc_middle` is also a pre-requisite for ensuring that we do not evaluate constants whose where clauses do not hold.
From this point it should be relatively simple (hah) to implement more complex normalization of type system constants such as: checking wf'ness before invoking CTFE machinery, or being able to normalize const aliases that still refer to generic parameters.
r? `@compiler-errors`
Feature gate yield expressions not in 2024
This changes it so that yield expressions are no longer allowed in the 2024 edition without a feature gate. We are currently only reserving the `gen` keyword in the 2024 edition, and not allowing anything else to be implicitly enabled by the edition.
In practice this doesn't have a significant difference since yield expressions can't really be used outside of coroutines or gen blocks, which have their own feature gates. However, it does affect what is accepted pre-expansion, and I would feel more comfortable not allowing yield expressions.
I believe the stabilization process for gen blocks or coroutines will not need to check the edition here, so this shouldn't ever be needed.
Remove attributes from generics in built-in derive macros
Related issue #132561
Removes all attributes from generics in the expanded implementations of built-in derive macros.
Make sure that we suggest turbofishing the right type arg for never suggestion
I had a bug where rust would suggest the wrong arg to turbofish `()` if there were any early-bound lifetimes...
r? WaffleLapkin
Don't use `maybe_unwrap_block` when checking for macro calls in a block expr
Fixes#131915
Using `maybe_unwrap_block` to determine if we are looking at a `{ mac_call!{} }` will fail sometimes as `mac_call!{}` could be a `StmtKind::MacCall` not a `StmtKind::Expr`. This caused the def collector to think that `{ mac_call!{} }` was a non-trivial const argument and create a definition for it even though it should not.
r? `@compiler-errors` cc `@camelid`
cleanup: Remove outdated comment of `thir_body`
When typeck fails, `thir_body` returns `ErrorGuaranteed` rather than empty body.
No other code follows this outdated description except `check_unsafety`, which is also cleaned up in this PR.
Provide placeholder generics for traits in "no method found for type parameter" suggestions
In the diagnostics for the error ``no method named `method` found for type parameter `T` in the current scope [E0599]``, the compiler will suggest adding bounds on `T` for traits that define a method named `method`. However, these suggestions didn't include any generic arguments, so applying them would result in a `missing generics for trait` or `missing lifetime specifier` error. This PR adds placeholder arguments to the suggestion in such cases. Specifically, I tried to base the placeholders off of what's done in suggestions for when generics are missing or too few are provided:
- The placeholder for a parameter without a default is the name of the parameter.
- Placeholders are not provided for parameters with defaults.
Placeholder arguments are enclosed in `/*` and `*/`, and the applicability of the suggestion is downgraded to `Applicability::HasPlaceholders` if any placeholders are provided.
Fixes#132407
