Currently, we check if the returned type equals to `tcx.ty_error()` not to emit
erroneous types, but this has a pitfall; for example,
`Option<[type error]> != tcx.ty_error()` holds.
Keep spans for generics in `#[derive(_)]` desugaring
Keep the spans for generics coming from a `derive`d Item, so that errors
and suggestions have better detail.
Fix#84003.
Updated error message for accidental uses of derive attribute as a crate attribute
This partially fixes the original issue #89566 by adding derive to the list of invalid crate attributes and then providing an updated error message however I'm not sure how to prevent the resolution error message from emitting without causing the compiler to just abort when it finds an invalid crate attribute (which I'd prefer not to do so we can find and emit other errors).
`@petrochenkov` I have been told you may have some insight on why it's emitting the resolution error though honestly I'm not sure if we need to worry about fixing it as long as we can provide the invalid crate attribute error also (which happens first anyway)
Fix ICE when `yield`ing in function returning `impl Trait`
Change an assert to a `delay_span_bug` and remove an unwrap, that should fix it.
Fixes#91477
Reintroduce `into_future` in `.await` desugaring
This is a reintroduction of the remaining parts from https://github.com/rust-lang/rust/pull/65244 that have not been relanded yet.
This isn't quite ready to merge yet. The last attempt was reverting due to performance regressions, so we need to make sure this does not introduce those issues again.
Issues #67644, #67982
/cc `@yoshuawuyts`
* Annotate `derive`d spans from the user's code with the appropciate context
* Add `Span::can_be_used_for_suggestion` to query if the underlying span
at the users' code
tidy run
update invalid crate attributes, improve error
update test outputs
de-capitalise error
update tests
Update invalid crate attributes, add help message
Update - generate span without using BytePos
Add correct dependancies
Update - generate suggestion without BytePos
Tidy run
update tests
Generate Suggestion without BytePos
Add all builtin attributes
add err builtin inner attr at top of crate
fix tests
add err builtin inner attr at top of crate
tidy fix
add err builtin inner attr at top of crate
As discovered in #85461, the MSVC linker treats weak symbols slightly
differently than unix-y linkers do. This causes link.exe to fail with
LNK1227 "conflicting weak extern definition" where as other targets are
able to link successfully.
This changes the dead functions from being generated as weak/hidden to
private/default which, as the LLVM reference says:
> Global values with “private” linkage are only directly accessible by
objects in the current module. In particular, linking code into a module
with a private global value may cause the private to be renamed as
necessary to avoid collisions. Because the symbol is private to the
module, all references can be updated. This doesn’t show up in any
symbol table in the object file.
This fixes the conflicting weak symbols but doesn't address the reason
*why* we have conflicting symbols for these dead functions. The test
cases added in this commit contain a minimal repro of the fundamental
issue which is that the logic used to decide what dead code functions
should be codegen'd in the current CGU doesn't take into account that
functions can be duplicated across multiple CGUs (for instance, in the
case of `#[inline(always)]` functions).
Fixing that is likely to be a more complex change (see
https://github.com/rust-lang/rust/issues/85461#issuecomment-985005805).
Fixes#85461
Revert "Auto merge of #91354 - fee1-dead:const_env, r=spastorino"
This reverts commit 18bb8c61a9, reversing
changes made to d9baa36190.
Reverts #91354 in order to address #91489. We would need to place this changes in a more granular way and would also be nice to address the small perf regression that was also introduced.
r? `@oli-obk`
cc `@fee1-dead`
Optimize `rustc_lexer`
The `cursor.first()` method in `rustc_lexer` now calls the `chars.next()` method instead of `chars.nth_char(0)`.
This allows LLVM to optimize the code better. The biggest win is that `eat_while()` is now fully inlined and generates better assembly. This improves the lexer's performance by 35% in a micro-benchmark I made (Lexing all 18MB of code in the compiler directory). But lexing is only a small part of the overall compilation time, so I don't know how significant it is.
Big thanks to criterion and `cargo asm`.
Fix ICE #91268 by checking that the snippet ends with a `)`
Fix#91268
Previously it was assumed that the last character of `snippet` will be a `)`, so using `snippet.len() - 1` as an index should be safe. However as we see in the test, it is possible to enter that branch without a closing `)`, and it will trigger the panic if the last character happens to be multibyte.
The fix is to ensure that the snippet ends with `)`, and skip the suggestion otherwise.
Implement write() method for Box<MaybeUninit<T>>
This adds method similar to `MaybeUninit::write` main difference being
it returns owned `Box`. This can be used to elide copy from stack
safely, however it's not currently tested that the optimization actually
occurs.
Analogous methods are not provided for `Rc` and `Arc` as those need to
handle the possibility of sharing. Some version of them may be added in
the future.
This was discussed in #63291 which this change extends.
Looks like Generator drop shims already have `post_borrowck_cleanup` run
on them. That's a bit surprising, since it means they're getting const-
and maybe borrow-checked? This merits further investigation, but for now
just preserve the status quo.
Rollup of 12 pull requests
Successful merges:
- #89954 (Fix legacy_const_generic doc arguments display)
- #91321 (Handle placeholder regions in NLL type outlive constraints)
- #91329 (Fix incorrect usage of `EvaluatedToOk` when evaluating `TypeOutlives`)
- #91364 (Improve error message for incorrect field accesses through raw pointers)
- #91387 (Clarify and tidy up explanation of E0038)
- #91410 (Move `#![feature(const_precise_live_drops)]` checks earlier in the pipeline)
- #91435 (Improve diagnostic for missing half of binary operator in `if` condition)
- #91444 (disable tests in Miri that take too long)
- #91457 (Add additional test from rust issue number 91068)
- #91460 (Document how `last_os_error` should be used)
- #91464 (Document file path case sensitivity)
- #91466 (Improve the comments in `Symbol::interner`.)
Failed merges:
r? `@ghost`
`@rustbot` modify labels: rollup
Improve diagnostic for missing half of binary operator in `if` condition
Fixes#91421. I've also changed it so that it doesn't consume the `else` token in the error case, because it will try to consume it again afterwards, leading to this incorrect error message (where the `else` reported as missing is actually there):
```
error: expected one of `.`, `;`, `?`, `else`, or an operator, found `{`
--> src/main.rs:4:12
|
4 | } else { 4 };
| ^ expected one of `.`, `;`, `?`, `else`, or an operator
```
r? `@lcnr`
Move `#![feature(const_precise_live_drops)]` checks earlier in the pipeline
Should mitigate the issues found during MCP on #73255.
Once this is done, we should clean up the queries a bit, since I think `mir_drops_elaborated_and_const_checked` can be merged back into `mir_promoted`.
Fixes#90770.
cc ``@rust-lang/wg-const-eval``
r? ``@nikomatsakis`` (since they reviewed #71824)
Clarify and tidy up explanation of E0038
I ran into E0038 (specifically the `Self:Sized` constraint on object-safety) the other day and it seemed to me that the explanations I found floating around the internet were a bit .. wrong. Like they didn't make sense. And then I went and checked the official explanation here and it didn't make sense either.
As far as I can tell (reading through the history of the RFCs), two totally different aspects of object-safety have got tangled up in much of the writing on the subject:
- Object-safety related to "not even theoretically possible" issues. This includes things like "methods that take or return Self by value", which obviously will never work for an unsized type in a world with fixed-size stack frames (and it'd be an opaque type anyways, which, ugh). This sort of thing was originally decided method-by-method, with non-object-safe methods stripped from objects; but in [RFC 0255](https://rust-lang.github.io/rfcs/0255-object-safety.html) this sort of per-impossible-method reasoning was made into a per-trait safety property (with the escape hatch left in where users could mark methods `where Self:Sized` to have them stripped before the trait's object safety is considered).
- Object-safety related to "totally possible but ergonomically a little awkward" issues. Specifically in a trait with `Trait:Sized`, there's no a priori reason why this constraint makes the trait impossible to make into an object -- imagine it had nothing but harmless `&self`-taking methods. No problem! Who cares if the Trait requires its implementing types to be sized? As far as I can tell reading the history here, in both RFC 0255 and then later in [RFC 0546](https://rust-lang.github.io/rfcs/0546-Self-not-sized-by-default.html) it seems that the motivation for making `Trait:Sized` be non-object-safe has _nothing to do_ with the impossibility of making objects out of such types, and everything to do with enabling "[a trait object SomeTrait to implement the trait SomeTrait](https://rust-lang.github.io/rfcs/0546-Self-not-sized-by-default.html#motivation)". That is, since `dyn Trait` is unsized, if `Trait:Sized` then you can never have the automatic (and reasonable) ergonomic implicit `impl Trait for dyn Trait`. And the authors of that RFC really wanted that automatic implicit implementation of `Trait` for `dyn Trait`. So they just defined `Trait:Sized` as non-object safe -- no `dyn Trait` can ever exist that the compiler can't synthesize such an impl for. Well enough!
However, I noticed in my reading-and-reconstruction that lots of documentation on the internet, including forum and Q&A site answers and (most worrying) the compiler explanation all kinda grasp at something like the first ("not theoretically possible") explanation, and fail to mention the second ("just an ergonomic constraint") explanation. So I figured I'd clean up the docs to clarify, maybe confuse the next person less (unless of course I'm misreading the history here and misunderstanding motives -- please let me know if so!)
While here I also did some cleanups:
- Rewrote the preamble, trying to help the user get a little better oriented (I found the existing preamble a bit scattered).
- Modernized notation (using `dyn Trait`)
- Changed the section headings to all be written with the same logical sense: to all be written as "conditions that violate object safety" rather than a mix of that and the negated form "conditions that must not happen in order to ensure object safety".
I think there's a fair bit more to clean up in this doc -- the later sections get a bit rambly and I suspect there should be a completely separated-out section covering the `where Self:Sized` escape hatch for instructing the compiler to "do the old thing" and strip methods off traits when turning them into objects (it's a bit buried as a digression in the individual sub-error sections). But I did what I had time for now.
Fix incorrect usage of `EvaluatedToOk` when evaluating `TypeOutlives`
A global predicate is not guarnatenteed to outlive all regions.
If the predicate involves late-bound regions, then it may fail
to outlive other regions (e.g. `for<'b> &'b bool: 'static` does not
hold)
We now only produce `EvaluatedToOk` when a global predicate has no
late-bound regions - in that case, the ony region that can be present
in the type is 'static
This adds method similar to `MaybeUninit::write` main difference being
it returns owned `Box`. This can be used to elide copy from stack
safely, however it's not currently tested that the optimization actually
occurs.
Analogous methods are not provided for `Rc` and `Arc` as those need to
handle the possibility of sharing. Some version of them may be added in
the future.
This was discussed in #63291 which this change extends.
Issue 90702 fix: Stop treating some crate loading failures as fatal errors
Surface mulitple `extern crate` resolution errors at a time.
This is achieved by creating a dummy crate, instead of aborting directly after the resolution error. The `ExternCrateError` has been added to allow propagating the resolution error from `rustc_metadata` crate to the `rustc_resolve` with a minimal public surface. The `import_extern_crate` function is a block that was factored out from `build_reduced_graph_for_item` for better organization. The only added functionality made to it where the added error handling in the `process_extern_crate` call. The remaining bits in this function are the same as before.
Resolves#90702
r? `@petrochenkov`
Disallow non-c-like but "fieldless" ADTs from being casted to integer if they use arbitrary enum discriminant
Code like
```rust
#[repr(u8)]
enum Enum {
Foo /* = 0 */,
Bar(),
Baz{}
}
let x = Enum::Bar() as u8;
```
seems to be unintentionally allowed so we couldn't disallow them now ~~, but we could disallow them if arbitrary enum discriminant is used before 1.56 hits stable~~ (stabilization was reverted).
Related: #88621
`@rustbot` label +T-lang
Cleanup: Eliminate ConstnessAnd
This is almost a behaviour-free change and purely a refactoring. "almost" because we appear to be using the wrong ParamEnv somewhere already, and this is now exposed by failing a test using the unstable `~const` feature.
We most definitely need to review all `without_const` and at some point should probably get rid of many of them by using `TraitPredicate` instead of `TraitRef`.
This is a continuation of https://github.com/rust-lang/rust/pull/90274.
r? `@oli-obk`
cc `@spastorino` `@ecstatic-morse`
... if they use arbitrary enum discriminant. Code like
```rust
enum Enum {
Foo = 1,
Bar(),
Baz{}
}
```
seems to be unintentionally allowed so we couldn't disallow them now,
but we could disallow them if arbitrary enum discriminant is used before
1.56 hits stable.
Include lint errors in error count for `-Ztreat-err-as-bug`
This was a regression from https://github.com/rust-lang/rust/pull/87337;
the `panic_if_treat_err_as_bug` function only checked the number of hard
errors, not the number of lint errors.
r? `@oli-obk`
expand: Turn `ast::Crate` into a first class expansion target
And stop creating a fake `mod` item for the crate root when expanding a crate, thus addressing FIXMEs left in https://github.com/rust-lang/rust/pull/82238, and making a step towards a proper support for crate-level macro attributes (cc #54726).
I haven't added token collection support for the whole crate in this PR, maybe later.
r? `@Aaron1011`
This was a regression from https://github.com/rust-lang/rust/pull/87337;
the `panic_if_treat_err_as_bug` function only checked the number of hard
errors, not the number of lint errors.
Fix bad `NodeId` limit checking.
`Resolver::next_node_id` converts a `u32` to a `usize` (which is
possibly bigger), does a checked add, and then converts the result back
to a `u32`. The `usize` conversion completely subverts the checked add!
This commit removes the conversion to/from `usize`.
Improve error message for `E0659` if the source is not available
Fixes#91028. The fix is similar to those in #89233 and #87088. With this change, instead of the dangling
```
note: `Option` could also refer to the enum defined here
```
I get
```
note: `Option` could also refer to an enum from prelude
```
If the standard library source code _is_ available, the output does not change.
Add support for LLVM coverage mapping format versions 5 and 6
This PR cherry-pick's Swatinem's initial commit in unsubmitted PR #90047.
My additional commit augments Swatinem's great starting point, but adds full support for LLVM
Coverage Mapping Format version 6, conditionally, if compiling with LLVM 13.
Version 6 requires adding the compilation directory when file paths are
relative, and since Rustc coverage maps use relative paths, we should
add the expected compilation directory entry.
Note, however, that with the compilation directory, coverage reports
from `llvm-cov show` can now report file names (when the report includes
more than one file) with the full absolute path to the file.
This would be a problem for test results, but the workaround (for the
rust coverage tests) is to include an additional `llvm-cov show`
parameter: `--compilation-dir=.`
When recovering from a `:` in a pattern, use adequate AST pattern
If the suggestion to use `::` instead of `:` in the pattern isn't correct, a second resolution error will be emitted.
`Resolver::next_node_id` converts a `u32` to a `usize` (which is
possibly bigger), does a checked add, and then converts the result back
to a `u32`. The `usize` conversion completely subverts the checked add!
This commit removes the conversion to/from `usize`.
Instead we run `RemoveFalseEdges` and `RemoveUninitDrops` at the
appropriate time. The extra `SimplifyCfg` avoids visiting unreachable
blocks during `RemoveUninitDrops`.
Otherwise dataflow state will propagate along false edges and cause
things to be marked as maybe init unnecessarily. These should be
separate, since `SimplifyBranches` also makes `if true {} else {}` into
a `goto`, which means we wouldn't lint anything in the `else` block.
This commit augments Swatinem's initial commit in uncommitted PR #90047,
which was a great starting point, but did not fully support LLVM
Coverage Mapping Format version 6.
Version 6 requires adding the compilation directory when file paths are
relative, and since Rustc coverage maps use relative paths, we should
add the expected compilation directory entry.
Note, however, that with the compilation directory, coverage reports
from `llvm-cov show` can now report file names (when the report includes
more than one file) with the full absolute path to the file.
This would be a problem for test results, but the workaround (for the
rust coverage tests) is to include an additional `llvm-cov show`
parameter: `--compilation-dir=.`
CTFE: support assert_zero_valid and assert_uninit_valid
This ensures the implementation of all three type-based assert_ intrinsics remains consistent in Miri.
`assert_inhabited` recently got stabilized in https://github.com/rust-lang/rust/pull/90896 (meaning stable `const fn` can call it), so do the same with these other intrinsics.
Cc ```@rust-lang/wg-const-eval```
Refactor EmitterWriter::emit_suggestion_default
Makes progress towards https://github.com/rust-lang/rust/issues/89979
Split into 2 commits:
* the first commit is purely a refactor and I verified that `./x.py test src/test/ui --stage 1` and `./x.py test src/test/rustdoc-ui --stage 1` continue to pass on this commit.
* ~~the second commit removes the empty trailing line from diff style suggestions.~~ - I discovered an issue with this so its just the refactor now.
r? diagnostics
This commit is intended to follow the stabilization disposition of the
FCP that has now finished in #84223. This stabilizes the ability to flag
thread local initializers as `const` expressions which enables the macro
to generate more efficient code for accessing it, notably removing
runtime checks for initialization.
More information can also be found in #84223 as well as the tests where
the feature usage was removed in this PR.
Closes#84223
Take a LocalDefId in expect_*item.
Items and item-likes are always HIR owners.
When trying to find such nodes, there is no ambiguity, the `LocalDefId` and the `HirId::owner` always match.
In such cases, `local_def_id_to_hir_id` does not carry any meaningful information, so we can just skip calling it altogether.
Nothing else makes sense, and there is no "danger" in doing so, as it only does something if there are const bounds, which are unstable. This used to happen implicitly via the inferctxt before, which was much more fragile.
Accumulate all values of `-C remark` option
When `-C remark=...` option is specified multiple times,
accumulate all values instead of using only the last one.
r? `@nikic`
Emit LLVM optimization remarks when enabled with `-Cremark`
The default diagnostic handler considers all remarks to be disabled by
default unless configured otherwise through LLVM internal flags:
`-pass-remarks`, `-pass-remarks-missed`, and `-pass-remarks-analysis`.
This behaviour makes `-Cremark` ineffective on its own.
Fix this by configuring a custom diagnostic handler that enables
optimization remarks based on the value of `-Cremark` option. With
`-Cremark=all` enabling all remarks.
Fixes#90924.
r? `@nikic`
A global predicate is not guarnatenteed to outlive all regions.
If the predicate involves late-bound regions, then it may fail
to outlive other regions (e.g. `for<'b> &'b bool: 'static` does not
hold)
We now only produce `EvaluatedToOk` when a global predicate has no
late-bound regions - in that case, the ony region that can be present
in the type is 'static
Fix ICE when lowering `trait A where for<'a> Self: 'a`
Fixes#88586.
r? `@jackh726`
Jack, this fix is much smaller in scope than what I think you were proposing in the issue. Let me know if you had a vision for a larger refactor here.
cc `@JohnTitor`
Perform Sync check on static items in wf-check instead of during const checks
r? `@RalfJung`
This check is solely happening on the signature of the static item and not on its body, therefor it belongs into wf-checking instead of const checking.
Make `TypeFolder::fold_*` return `Result`
Implements rust-lang/compiler-team#432.
Initially this is just a rebase of `@LeSeulArtichaut's` work in #85469 (abandoned; see https://github.com/rust-lang/rust/pull/85485#issuecomment-908781112). At that time, it caused a regression in performance that required some further exploration... with this rebased PR bors can hopefully report some perf analysis from which we can investigate further (if the regression is indeed still present).
r? `@jackh726` cc `@nikomatsakis`
Only check for errors in predicate when skipping impl assembly
Prior to PR #91205, checking for errors in the overall obligation
would check checking the `ParamEnv`, due to an incorrect
`super_visit_with` impl. With this bug fixed, we will now
bail out of impl candidate assembly if the `ParamEnv` contains
any error types.
In practice, this appears to be overly conservative - when an error
occurs early in compilation, we end up giving up early for some
predicates that we could have successfully evaluated without overflow.
By only checking for errors in the predicate itself, we avoid causing
additional spurious 'type annotations needed' errors after a 'real'
error has already occurred.
With this PR, the diagnostic changes caused by PR #91205 are reverted.
Prior to PR #91205, checking for errors in the overall obligation
would check checking the `ParamEnv`, due to an incorrect
`super_visit_with` impl. With this bug fixed, we will now
bail out of impl candidate assembly if the `ParamEnv` contains
any error types.
In practice, this appears to be overly conservative - when an error
occurs early in compilation, we end up giving up early for some
predicates that we could have successfully evaluated without overflow.
By only checking for errors in the predicate itself, we avoid causing
additional spurious 'type annotations needed' errors after a 'real'
error has already occurred.
With this PR, the diagnostic changes caused by PR #91205 are reverted.
Account for incorrect `where T::Assoc = Ty` bound
Provide suggestoin to constrain trait bound for associated type.
Revert incorrect changes to `missing-bounds` test.
Address part of #20041.
Rollup of 4 pull requests
Successful merges:
- #91169 (Change cg_ssa's get_param to borrow the builder mutably)
- #91176 (If the thread does not get the lock in the short term, yield the CPU)
- #91212 (Fix ICE due to out-of-bounds statement index when reporting borrowck error)
- #91225 (Fix invalid scrollbar display on source code page)
Failed merges:
r? `@ghost`
`@rustbot` modify labels: rollup
Fix ICE due to out-of-bounds statement index when reporting borrowck error
Replace an `[index]` with a `.get` when `statement_index` points to a basic-block terminator (and is therefore out-of-bounds in the statements list).
Fixes#91206
Cc ``@camsteffen``
r? ``@oli-obk``
Change cg_ssa's get_param to borrow the builder mutably
This is a small change to make `get_param` more flexible for codegens that may need to modify things when retrieving function parameters.
This will currently only be used by [rustc_codegen_nvvm](https://github.com/Rust-GPU/Rust-CUDA) (my own project), but may be useful to more codegens in the future.
This is needed because cg_nvvm needs to remap certain types to libnvvm-friendly types, such as `i128` -> `<2 x i64>`. Because cg_ssa does not give mutable access to the builder, i resorted to using a mutex:
```rs
fn get_param(&self, index: usize) -> Self::Value {
let val = llvm::get_param(self.llfn(), index as c_uint);
trace!("Get param `{:?}`", val);
unsafe {
let llfnty = LLVMRustGetFunctionType(self.llfn());
let map = self.remapped_integer_args.borrow();
if let Some((_, key)) = map.get(llfnty) {
if let Some((_, new_ty)) = key.iter().find(|t| t.0 == index) {
trace!("Casting irregular param {:?} to {:?}", val, new_ty);
return transmute_llval(
*self.llbuilder.lock().unwrap(),
&self.cx,
val,
*new_ty,
);
}
}
val
}
}
```
However, i predict this is pretty bad for performance, considering how much builders are called during codegen, so i would greatly appreciate having a more flexible API for this.
Fix stack overflow in `usefulness.rs`
Fix#88747
Applied the suggestion from `@nbdd0121,` not sure if this has any drawbacks. The first call to `ensure_sufficient_stack` is not needed to fix the test case, but I added it to be safe.
Visit `param_env` field in Obligation's `TypeFoldable` impl
This oversight appears to have gone unnoticed for a long time
without causing issues, but it should still be fixed.
