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 7 pull requests
Successful merges:
- #113510 (Document soundness of Integer -> Pointer -> Integer conversions in `const` contexts.)
- #114412 (document our assumptions about symbols provided by the libc)
- #114813 (explain why we can mutate the FPU control word)
- #115523 (improve `AttrTokenStream`)
- #115536 (interpret: make MemPlace, Place, Operand types private to the interpreter)
- #115540 (Support debuginfo for custom MIR.)
- #115563 (llvm-wrapper: adapt for LLVM API change)
r? `@ghost`
`@rustbot` modify labels: rollup
support `{disable,enable}-patch-binaries-for-nix` in configure.py
Provide the control of `patch-binaries-for-nix` flag from configure.py without requiring manual editing.
It's useful when:
bf1e3f31f9/src/bootstrap/bootstrap.py (L661-L667)
Add `fmease` to rustdoc review rotations
`@fmease` asked me if it was okay for them to be part of the rustdoc review rotation. Since they are already reviewing a lot of rustdoc PRs, I think it's fine to add them to the rotation.
What do you think `@rust-lang/rustdoc` ?
r? rust-lang/rustdoc
Retry download of rustc-perf in opt-dist
This should help resolving spurious network errors. It also increases the timeout for the archive download.
r? `@Mark-Simulacrum`
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
Expose more information with DefId in smir
Currently `Debug` for `DefId` doesn't provide enough information, this changes so that we get `usize` of the `DefId` and the name of it.
r? `@oli-obk`
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`
Add an allow attribute suggestion along with the implied by suggestion
This PR adds an `#[allow(...)]` attribute hep suggestion along with the implied by suggestion:
```diff
note: `-W dead-code` implied by `-W unused`
+ help: to override `-W unused` add `#[allow(dead_code)]`
```
This PR also adds the `OnceHelp` lint level (similar to `OnceNote`) to only put the help message one time, like the implied note.
Related to https://github.com/rust-lang/rust/issues/114030
Move RawOsError defination to sys
This was originally a part of https://github.com/rust-lang/rust/pull/105861, but I feel it should be its own PR since the raw os error is still unstable.
Encode DepKind as u16
The derived Encodable/Decodable impls serialize/deserialize as a varint, which results in a lot of code size around the encoding/decoding of these types which isn't justified: The full range of values here is rather small but doesn't quite fit in to a `u8`. Growing _all_ serialized `DepKind` to 2 bytes costs us on average 1% size in the incr comp dep graph, which I plan to recoup in https://github.com/rust-lang/rust/pull/110050 by taking advantage of the unused bits in all the serialized `DepKind`.
r? `@nnethercote`
Outline panicking code for `RefCell::borrow` and `RefCell::borrow_mut`
This outlines panicking code for `RefCell::borrow` and `RefCell::borrow_mut` to reduce code size.
