Add explanatory note to 'expected item' error
Fixes#113110
It changes the diagnostic from this:
```
error: expected item, found `5`
--> ../test.rs:1:1
|
1 | 5
| ^ expected item
```
to this:
```
error: expected item, found `5`
--> ../test.rs:1:1
|
1 | 5
| ^ expected item
|
= note: items are things that can appear at the root of a module
= note: for a full list see https://doc.rust-lang.org/reference/items.html
```
Represent MIR composite debuginfo as projections instead of aggregates
Composite debuginfo for MIR is currently represented as
```
debug name => Type { projection1 => place1, projection2 => place2 };
```
ie. a single `VarDebugInfo` object with that name, and its value a `VarDebugInfoContents::Composite`.
This PR proposes to reverse the representation to be
```
debug name.projection1 => place1;
debug name.projection2 => place2;
```
ie. multiple `VarDebugInfo` objects with each their projection.
This simplifies the handling of composite debuginfo by the compiler by avoiding weird nesting.
Based on https://github.com/rust-lang/rust/pull/115139
Fix error report for size overflow from transmute
Fixes#115402
The span in the error reporting always points to the `dst`, this is an old issue, I may open another PR to fix it.
Make if let guard parsing consistent with normal guards
- Add tests that struct expressions are not allowed in `if let` and `while let` (no change, consistent with `if` and `while`)
- Allow struct expressions in `if let` guards (consistent with `if` guards).
r? `@cjgillot`
Closes#93817
cc #51114
Add support to return value in StableMIR interface and not crash due to compilation error
Invoking `StableMir::run()` on a crate that has any compilation error was crashing the entire process. Instead, return a `CompilerError` so the user knows compilation did not succeed. I believe ICE will also be converted to `CompilerError`.
I'm also adding a possibility for the callback to return a value. I think it will be handy for users (at least it was for my current task of implementing a tool to validate stable-mir). However, if people disagree, I can remove that.
coverage: Explicitly test the coverage maps produced by codegen/LLVM
Our existing coverage tests verify the output of end-to-end coverage reports, but we don't have any way to test the specific mapping information (code regions and their associated counters) that are emitted by `rustc_codegen_llvm` and LLVM. That makes it harder to to be confident in changes that would modify those mappings (whether deliberately or accidentally).
This PR addresses that by adding a new `coverage-map` test suite that does the following:
- Compiles test files to LLVM IR assembly (`.ll`)
- Feeds those IR files to a custom tool (`src/tools/coverage-dump`) that extracts and decodes coverage mappings, and prints them in a more human-readable format
- Checks the output of that tool against known-good snapshots
---
I recommend excluding the last commit while reviewing the main changes, because that last commit is just ~40 test files copied over from `tests/run-coverage`, plus their blessed coverage-map snapshots and a readme file. Those snapshots aren't really intended to be checked by hand; they're mostly there to increase the chances that an unintended change to coverage maps will be observable (even if it requires relatively specific circumstances to manifest).
Rollup of 5 pull requests
Successful merges:
- #115353 (Emit error instead of ICE when optimized MIR is missing)
- #115488 (Take `&mut Results` in `ResultsVisitor`)
- #115492 (Allow `large_assignments` for Box/Arc/Rc initialization)
- #115519 (Don't ICE on associated type projection without feature gate in new solver)
- #115534 (Expose more information with DefId in smir)
r? `@ghost`
`@rustbot` modify labels: rollup
Don't ICE on associated type projection without feature gate in new solver
Self-explanatory, we should avoid ICEs when the feature gate is not enabled. Continue to ICE when the feature gate *is* enabled, though.
Fixes#115500
Allow `large_assignments` for Box/Arc/Rc initialization
Does the `stop linting in box/arc initialization` task of #83518.
r? `@oli-obk` who is E-mentor.
The output of these tests is too complicated to comfortably verify by hand, but
we can still use them to observe changes to the underlying mappings produced by
codegen/LLVM.
If these tests fail due to non-coverage changes (e.g. in HIR-to-MIR lowering or
MIR optimizations), it should usually be OK to just `--bless` them, as long as
the `run-coverage` test suite still works.
We compile each test file to LLVM IR assembly, and then pass that IR to a
dedicated program that can decode LLVM coverage maps and print them in a more
human-readable format. We can then check that output against known-good
snapshots.
This test suite has some advantages over the existing `run-coverage` tests:
- We can test coverage instrumentation without needing to run target binaries.
- We can observe subtle improvements/regressions in the underlying coverage
mappings that don't make a visible difference to coverage reports.
Do not require associated types with Self: Sized to uphold bounds when confirming object candidate
RPITITs and associated types that have `Self: Sized` bounds are opted out of the `dyn Trait` well-formedness check that happens during confirmation. This ensures that we can actually *use* `dyn Trait`s that have associated types that, e.g., have GATs and RPITITs and other naughty things as long as those are opted-out of object safety via a `Self: Sized` bound.
Fixes#115464
This seems like a natural part of https://github.com/rust-lang/rust/pull/112319#issuecomment-1592574451, and I don't think needs re-litigation.
r? `@oli-obk`
