[AIX] Lint on structs that have a different alignment in AIX's C ABI
This PR adds a linting diagnostic on AIX for repr(C) structs that are required to follow
the power alignment rule. A repr(C) struct needs to follow the power alignment rule if
the struct:
- Has a floating-point data type (greater than 4-bytes) as its first member, or
- The first member of the struct is an aggregate, whose recursively first member is a
floating-point data type (greater than 4-bytes).
The power alignment rule for eligible structs is currently unimplemented, so a linting
diagnostic is produced when such a struct is encountered.
Detect missing fields with default values and suggest `..`
When a struct ctor use has missing fields, if all those missing fields have defaults, suggest `..`:
```
error[E0063]: missing fields `field1` and `field2` in initializer of `S`
--> $DIR/non-exhaustive-ctor.rs:16:13
|
LL | let _ = S { field: () };
| ^ missing `field1` and `field2`
|
help: all remaining fields have default values, you can use those values with `..`
|
LL | let _ = S { field: (), .. };
| ++++
```
Properly note when query stack is being cut off
cc #70953
also, i'm not certain whether we should even limit this at all. i don't see the problem with printing the full query stack, apparently it was limited b/c we used to ICE? but we're already printing the full stack to disk since #108714.
r? oli-obk
Point at invalid utf-8 span on user's source code
```
error: couldn't read `$DIR/not-utf8-bin-file.rs`: stream did not contain valid UTF-8
--> $DIR/not-utf8-2.rs:6:5
|
LL | include!("not-utf8-bin-file.rs");
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
|
note: byte `193` is not valid utf-8
--> $DIR/not-utf8-bin-file.rs:2:14
|
LL | let _ = "�|�␂!5�cc␕␂��";
| ^
= note: this error originates in the macro `include` (in Nightly builds, run with -Z macro-backtrace for more info)
```
When we attempt to load a Rust source code file, if there is a OS file failure we try reading the file as bytes. If that succeeds we try to turn it into UTF-8. If *that* fails, we provide additional context about *where* the file has the first invalid UTF-8 character.
Fix#76869.
Fix ICE-133117: multiple never-pattern arm doesn't have false_edge_start_block
Fixes#133117 , and close fixes#133063 , fixes#130779
In order to fix ICE-133117, at first I needed to tackle to ICE-133063 (this fixed 130779 as well).
### ICE-133063 and ICE-130779
This ICE is caused by those steps:
1. An arm has or-pattern, and all of the sub-candidates are never-pattern
2. In that case, all sub-candidates are removed in remove_never_subcandidates(). So the arm (candidate) has no sub-candidate.
3. In the current implementation, if there is no sub-candidate, the function assigns `pre_binding_block` into the candidate ([here](https://github.com/rust-lang/rust/blob/master/compiler/rustc_mir_build/src/builder/matches/mod.rs#L2002-L2004)). However, otherwise_block should be assigned to the candidate as well, because the otherwise_block is unwrapped in multiple place (like in lower_match_tree()). As a result, it causes the panic.
I simply added the same block as pre_binding_block into otherwise_block, but I'm wondering if there is a better block to assign to otherwise_block (is it ok to assign the same block into pre_binding and otherwise?)
### ICE-133117
This is caused by those steps:
1. There are two arms, both are or-pattern and each has one match-pair (in the test code, both are `(!|!)`), and the second arm has a guard.
2. In match_candidate() for the first arm, it expands the second arm’s sub-candidates as well ([here](https://github.com/rust-lang/rust/blob/master/compiler/rustc_mir_build/src/builder/matches/mod.rs#L1800-L1805)). As a result, the root candidate of the second arm is not evaluated/modified in match_candidate(). So a false_edge_start_block is not assigned to the candidate.
3. merge_trivial_subcandidates() is called against the candidate for the second arm. It just returns immediately because the candidate has a guard. So a flase_edge_start_block is not assigned to the candidate also in this function.
4. remove_never_subcandidates() is called against the candidate. Since all sub-candidates are never-pattern. they are removed.
5. In lower_match_tree(), since there is no sub-candidate for the candidate, the candidate itself is evaluated in visit_leave_rev ([here](https://github.com/rust-lang/rust/blob/master/compiler/rustc_mir_build/src/builder/matches/mod.rs#L1532)). Because the candidate has no false_edge_start_block, it causes the panic.
So I modified the order of if blocks in merge_trivial_subcandidates() to assign a false_edge_start_block if the candidate doesn't have.
Don't pick `T: FnPtr` nested goals as the leaf goal in diagnostics for new solver
r? `@lcnr`
See `tests/ui/traits/next-solver/diagnostics/dont-pick-fnptr-bound-as-leaf.rs` for a minimized example of what code this affects the diagnostics off. The output of running nightly `-Znext-solver` on that test is the following:
```
error[E0277]: the trait bound `Foo: Trait` is not satisfied
--> src/lib.rs:14:20
|
14 | requires_trait(Foo);
| -------------- ^^^ the trait `FnPtr` is not implemented for `Foo`
| |
| required by a bound introduced by this call
|
note: required for `Foo` to implement `Trait`
--> src/lib.rs:7:16
|
7 | impl<T: FnPtr> Trait for T {}
| ----- ^^^^^ ^
| |
| unsatisfied trait bound introduced here
note: required by a bound in `requires_trait`
--> src/lib.rs:11:22
|
11 | fn requires_trait<T: Trait>(_: T) {}
| ^^^^^ required by this bound in `requires_trait`
```
Part of rust-lang/trait-system-refactor-initiative#148
Use `structurally_normalize` instead of manual `normalizes-to` goals in alias relate errors
r? `@lcnr`
I added `structurally_normalize_term` so that code that is generic over ty or const can use the structurally normalize helpers. See `tests/ui/traits/next-solver/diagnostics/alias_relate_error_uses_structurally_normalize.rs` for a description of the reason for the (now fixed) ICEs
Refactor dyn-compatibility error and suggestions
This CL makes a number of small changes to dyn compatibility errors:
- "object safety" has been renamed to "dyn-compatibility" throughout
- "Convert to enum" suggestions are no longer generated when there exists a type-generic impl of the trait or an impl for `dyn OtherTrait`
- Several error messages are reorganized for user readability
Additionally, the dyn compatibility error creation code has been split out into functions.
cc #132713
cc #133267
r? `@compiler-errors`
This CL makes a number of small changes to dyn compatibility errors:
- "object safety" has been renamed to "dyn-compatibility" throughout
- "Convert to enum" suggestions are no longer generated when there
exists a type-generic impl of the trait or an impl for `dyn OtherTrait`
- Several error messages are reorganized for user readability
Additionally, the dyn compatibility error creation code has been
split out into functions.
cc #132713
cc #133267
Properly record metavar spans for other expansions other than TT
This properly records metavar spans for nonterminals other than tokentree. This means that we operations like `span.to(other_span)` work correctly for macros. As you can see, other diagnostics involving metavars have improved as a result.
Fixes#132908
Alternative to #133270
cc `@ehuss`
cc `@petrochenkov`
```
error: couldn't read `$DIR/not-utf8-bin-file.rs`: stream did not contain valid UTF-8
--> $DIR/not-utf8-2.rs:6:5
|
LL | include!("not-utf8-bin-file.rs");
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
|
note: `[193]` is not valid utf-8
--> $DIR/not-utf8-bin-file.rs:2:14
|
LL | let _ = "�|�␂!5�cc␕␂��";
| ^
= note: this error originates in the macro `include` (in Nightly builds, run with -Z macro-backtrace for more info)
```
When we attempt to load a Rust source code file, if there is a OS file failure we try reading the file as bytes. If that succeeds we try to turn it into UTF-8. If *that* fails, we provide additional context about *where* the file has the first invalid UTF-8 character.
Fix#76869.
Add fixme and test for issue #135289
This PR:
- adds a test minimizing issue #135289 for PR #135310
- adds a fixme about the suboptimal fix for the ICE
I've verified the test indeed ICEs with 3f2f695d68 reverted.
r? `@estebank`
When a struct definition has default field values, and the use struct ctor has missing field, if all those missing fields have defaults suggest `..`:
```
error[E0063]: missing fields `field1` and `field2` in initializer of `S`
--> $DIR/non-exhaustive-ctor.rs:16:13
|
LL | let _ = S { field: () };
| ^ missing `field1` and `field2`
|
help: all remaining fields have defaults, use `..`
|
LL | let _ = S { field: (), .. };
| ++++
```
remove support for the (unstable) #[start] attribute
As explained by `@Noratrieb:`
`#[start]` should be deleted. It's nothing but an accidentally leaked implementation detail that's a not very useful mix between "portable" entrypoint logic and bad abstraction.
I think the way the stable user-facing entrypoint should work (and works today on stable) is pretty simple:
- `std`-using cross-platform programs should use `fn main()`. the compiler, together with `std`, will then ensure that code ends up at `main` (by having a platform-specific entrypoint that gets directed through `lang_start` in `std` to `main` - but that's just an implementation detail)
- `no_std` platform-specific programs should use `#![no_main]` and define their own platform-specific entrypoint symbol with `#[no_mangle]`, like `main`, `_start`, `WinMain` or `my_embedded_platform_wants_to_start_here`. most of them only support a single platform anyways, and need cfg for the different platform's ways of passing arguments or other things *anyways*
`#[start]` is in a super weird position of being neither of those two. It tries to pretend that it's cross-platform, but its signature is a total lie. Those arguments are just stubbed out to zero on ~~Windows~~ wasm, for example. It also only handles the platform-specific entrypoints for a few platforms that are supported by `std`, like Windows or Unix-likes. `my_embedded_platform_wants_to_start_here` can't use it, and neither could a libc-less Linux program.
So we have an attribute that only works in some cases anyways, that has a signature that's a total lie (and a signature that, as I might want to add, has changed recently, and that I definitely would not be comfortable giving *any* stability guarantees on), and where there's a pretty easy way to get things working without it in the first place.
Note that this feature has **not** been RFCed in the first place.
*This comment was posted [in May](https://github.com/rust-lang/rust/issues/29633#issuecomment-2088596042) and so far nobody spoke up in that issue with a usecase that would require keeping the attribute.*
Closes https://github.com/rust-lang/rust/issues/29633
try-job: x86_64-gnu-nopt
try-job: x86_64-msvc-1
try-job: x86_64-msvc-2
try-job: test-various
Since there are so many ways to write these, I've opted to only include
two sorts of test: simple tests that directly target the rules differing
between rulesets and nuanced tests that produce different errors under
different rulesets. I've also tried not to add any duplicate tests.
`well-typed-edition-2024.rs` already has tests disagreeing with stable,
so I've opted not to include any in this commit that are well-typed
under the new rules.
This serves two purposes.
First, they're additional tests that stable Rust behavior hasn't been
messed with. There's plenty of other pattern tests, so this is less
important, but these at least are targeted at what's being changed.
Second, this helps document exactly where the new rulesets agree and
disagree with stable pattern typing. This will be especially important
after the new rules for old editions are updated, since they need to be
strictly more permissive; any patterns well-typed on stable should also
be well-typed with the same resultant bindings on the (upcoming) new new
old-edition rules.
The unusual test ordering on `borrowck-errors.rs` and
`ref-binding-on-inh-ref-errors.rs` are to hopefully reduce how much
adding new tests will mess with line numbers in their stderr.
Rework dyn trait lowering to stop being so intertwined with trait alias expansion
This PR reworks the trait object lowering code to stop handling trait aliases so funky, and removes the `TraitAliasExpander` in favor of a much simpler design. This refactoring is important for making the code that I'm writing in https://github.com/rust-lang/rust/pull/133397 understandable and easy to maintain, so the diagnostics regressions are IMO inevitable.
In the old trait object lowering code, we used to be a bit sloppy with the lists of traits in their unexpanded and expanded forms. This PR largely rewrites this logic to expand the trait aliases *once* and handle them more responsibly throughout afterwards.
Please review this with whitespace disabled.
r? lcnr
I think the diagnostic could use some work, but it's more helpful than
the alternative. The previous error was misleading, since it ignored the
inherited reference altogether.
These come directly from the "Compare" tab of Typing Rust Patterns,
though they had to be split across multiple files. They're not
comprehensive, but they do provide some previously-missing coverage and
are easier to check against the spec. Possibly they should be split up
some more, since `pattern-errors.rs` is getting a bit unwieldy, but I'm
not sure how best to go about that.
The debug assertion ensuring that the pattern mutability cap holds
assumes the presence of Rule 3, so it now checks for that. I
considered going back to only tracking the mutability cap when Rule 3
is present, but since the mutability cap is used in Rule 5's
implementation too, the debug assertion would still need to check
which typing rules are present.
This also required some changes to tests:
- `ref_pat_eat_one_layer_2021.rs` had a test for Rule 3; I'll be
handling tests for earlier editions in a later commit, so as a stopgap
I've #[cfg]ed it out.
- One test case had to be moved from `well-typed-edition-2024.rs` to
`borrowck-errors.rs` in order to get borrowck to run on it and emit an
error.
