This argument isn't necessary for WebAssembly targets since `wasm-ld` is
the only linker for the targets. Passing it otherwise interferes with
Clang's linker selection on `wasm32-wasip2` so avoid it altogether.
Now that branch and MC/DC mappings have been split out into separate types and
vectors, this enum is no longer needed, since it only represents ordinary
"code" regions.
(We can revisit this decision if we ever add support for other region kinds,
such as skipped regions or expansion regions. But at that point, we might just
add new structs/vectors for those kinds as well.)
Some hir cleanups
It seemed odd to not put `AnonConst` in the arena, compared with the other types that we did put into an arena. This way we can also give it a `Span` without growing a lot of other HIR data structures because of the extra field.
r? compiler
This commit changes the LLVM target of for the Rust `wasm32-wasip2`
target to `wasm32-wasip2` as well. LLVM does a bit of detection on the
target string to know when to call `wasm-component-ld` vs `wasm-ld` so
otherwise clang is invoking the wrong linker.
Account for immutably borrowed locals in MIR copy-prop and GVN
For the most part, we consider that immutably borrowed `Freeze` locals still fulfill SSA conditions. As the borrow is immutable, any use of the local will have the value given by the single assignment, and there can be no surprise.
This allows copy-prop to merge a non-borrowed local with a borrowed local. We chose to keep copy-classes heads unborrowed, as those may be easier to optimize in later passes.
This also allows to GVN the value behind an immutable borrow. If a SSA local is borrowed, dereferencing that borrow is equivalent to copying the local's value: re-executing the assignment between the borrow and the dereference would be UB.
r? `@ghost` for perf
Describe and use CStr literals in CStr and CString docs
Mention CStr literals in the description of both types, and use them in some of the code samples for CStr. This is intended to make C string literals more discoverable.
Additionally, I don't think the orange "This example is not tested" warnings are very encouraging, so I have made the examples on `CStr` build.
coverage: Clean up creation of MC/DC condition bitmaps
This PR improves the code for creating and initializing [MC/DC](https://en.wikipedia.org/wiki/Modified_condition/decision_coverage) condition bitmap variables, as introduced by #123409 and modified by #124255.
- The condition bitmap variables are now created eagerly at the start of per-function codegen, via a new `init_coverage` method in `CoverageInfoBuilderMethods`. This avoids having to retroactively create the bitmaps while doing codegen for an individual coverage statement.
- As a result, we can now create and initialize those bitmaps using existing safe APIs, instead of having to perform our own unsafe call to `llvm::LLVMBuildAlloca`.
- This PR also tweaks the way we count the number of condition bitmaps needed, by tracking the total number of bitmaps needed (max depth + 1), instead of only tracking the maximum depth. This reduces the potential for subtle off-by-one confusion.
default_alloc_error_hook: explain difference to default __rdl_oom in alloc
Though I'm not sure if that is really the reason that this code is duplicated. On no_std it may already be possible to call user-defined code on allocation failure.
Implement ptr_as_ref_unchecked
Implementation of #122034.
Prefixed the feature name with `ptr_` for clarity.
Linked const-unstability to #91822, so the post there should probably be updated to mentions the 3 new methods when/if this PR is merged.
Stabilize the size of incr comp object file names
The current implementation does not produce stable-length paths, and we create the paths in a way that makes our allocation behavior is nondeterministic. I think `@eddyb` fixed a number of other cases like this in the past, and this PR fixes another one. Whether that actually matters I have no idea, but we still have bimodal behavior in rustc-perf and the non-uniformity in `find` and `ls` was bothering me.
I've also removed the truncation of the mangled CGU names. Before this PR incr comp paths look like this:
```
target/debug/incremental/scratch-38izrrq90cex7/s-gux6gz0ow8-1ph76gg-ewe1xj434l26w9up5bedsojpd/261xgo1oqnd90ry5.o
```
And after, they look like this:
```
target/debug/incremental/scratch-035omutqbfkbw/s-gux6borni0-16r3v1j-6n64tmwqzchtgqzwwim5amuga/55v2re42sztc8je9bva6g8ft3.o
```
On the one hand, I'm sure this will break some people's builds because they're on Windows and only a few bytes from the path length limit. But if we're that seriously worried about the length of our file names, I have some other ideas on how to make them smaller. And last time I deleted some hash truncations from the compiler, there was a huge drop in the number if incremental compilation ICEs that were reported: https://github.com/rust-lang/rust/pull/110367https://github.com/rust-lang/rust/pull/110367
---
Upon further reading, this PR actually fixes a bug. This comment says the CGU names are supposed to be a fixed-length hash, and before this PR they aren't: ca7d34efa9/compiler/rustc_monomorphize/src/partitioning.rs (L445-L448)
Rollup of 6 pull requests
Successful merges:
- #124461 (handle the targets that are missing in stage0)
- #124492 (Generalize `adjust_from_tcx` for `Allocation`)
- #124588 (Use `ObligationCtxt` in favor of `TraitEngine` in many more places)
- #124612 (Add support for inputing via stdin with run-make-support)
- #124613 (Allow fmt to run on rmake.rs test files)
- #124649 (Fix HorizonOS build broken by #124210)
r? `@ghost`
`@rustbot` modify labels: rollup
We are now using Docker caching directly rather than downloading archives from S3, so it should not be needed.
This should unblock reusing the cache locally.
Fix HorizonOS build broken by #124210
HorizonOS (for the Tier-3 target `armv6k-nintendo-3ds`) does not support `dirfd()`, as many other similar targets.
Allow fmt to run on rmake.rs test files
As discussed with `@jieyouxu,` `rmake.rs` from the `run-make` testsuite would benefit from being formatted as well.
Only thing needed to be done for it to work: allow support for `!` in our `rustfmt.toml` file parsing.
r? `@onur-ozkan`
Add support for inputing via stdin with run-make-support
This PR adds the facility to set a input bytes that will be passed via the standard input.
This is useful for testing `rustc -` (and soon `rustdoc -`).
In #124611 took the approach of having a dedicated `run` method but it is not very convenient to use and would necessitate many functions, one for success, one for fail, ...
Instead this PR takes a different approach and allows setting the input bytes as if it were a parameter and when calling the (now custom) `output` function, we write the input bytes into stdin. I think this gives us maximum flexibility in the implementation and a simple interface for users.
To test this new logic I ported `tests/run-make/stdin-non-utf8/` to an `rmake.rs` one.
r? `@jieyouxu`
Generalize `adjust_from_tcx` for `Allocation`
Previously, `adjust_from_tcx` would take an `Allocation` and "adjust allocation from the ones in `tcx` to a custom Machine instance [...]".
This PR generalizes this so the Machine instance can also determine the `Bytes` type of the output `Allocation`.
r? `@RalfJung`
handle the targets that are missing in stage0
During sanity checks, we search for target names to determine if they exist in the compiler's built-in target list (`rustc --print target-list`). While a target name may be present in the stage2 compiler, it might not yet be included in stage0. This PR handles that difference.
Follow-up of https://github.com/rust-lang/rust/pull/123546
