NVPTX: Avoid PassMode::Direct for args in C abi
Fixes#117480
I must admit that I'm confused about `PassMode` altogether, is there a good sum-up threads for this anywhere? I'm especially confused about how "indirect" and "byval" goes together. To me it seems like "indirect" basically means "use a indirection through a pointer", while "byval" basically means "do not use indirection through a pointer".
The return used to keep `PassMode::Direct` for small aggregates. It turns out that `make_indirect` messes up the tests and one way to fix it is to keep `PassMode::Direct` for all aggregates. I have mostly seen this PassMode mentioned for args. Is it also a problem for returns? When experimenting with `byval` as an alternative i ran into [this assert](61a3eea804/compiler/rustc_codegen_llvm/src/abi.rs (L463C22-L463C22))
I have added tests for the same kind of types that is already tested for the "ptx-kernel" abi. The tests cannot be enabled until something like #117458 is completed and merged.
CC: ``@RalfJung`` since you seem to be the expert on this and have already helped me out tremendously
CC: ``@RDambrosio016`` in case this influence your work on `rustc_codegen_nvvm`
``@rustbot`` label +O-NVPTX
Omit non-needs_drop drop_in_place in vtables
This replaces the drop_in_place reference with null in vtables. On librustc_driver.so, this drops about ~17k (11%) dynamic relocations from the output, since many vtables can now be placed in read-only memory, rather than having a relocated pointer included.
This makes a tradeoff by adding a null check at vtable call sites. I'm not sure that's readily avoidable without changing the vtable format (e.g., so that we can use a pc-relative relocation instead of an absolute address, and avoid the dynamic relocation that way). But it seems likely that the check is cheap at runtime.
Accepted MCP: https://github.com/rust-lang/compiler-team/issues/730
When encountering `use foo::*;` where `foo` fails to be found, and we later
encounter resolution errors, we silence those later errors.
A single case of the above, for an *existing* import on a big codebase would
otherwise have a huge number of knock-down spurious errors.
Ideally, instead of a global flag to silence all subsequent resolve errors,
we'd want to introduce an unameable binding in the appropriate rib as a
sentinel when there's a failed glob import, so when we encounter a resolve
error we can search for that sentinel and if found, and only then, silence
that error. The current approach is just a quick proof of concept to
iterate over.
Partially address #96799.
This adds the `only-apple`/`ignore-apple` compiletest directive, and
uses that basically everywhere instead of `only-macos`/`ignore-macos`.
Some of the updates in `run-make` are a bit redundant, as they use
`ignore-cross-compile` and won't run on iOS - but using Apple in these
is still more correct, so I've made that change anyhow.
`-Znext-solver`: eagerly normalize when adding goals
fixes#125269. I am not totally with this fix and going to keep this open until we have a more general discussion about how to handle hangs caused by lazy norm in the new solver.
We still check for the `rental`/`allsorts-rental` crates. But now if
they are detected we just emit a fatal error, instead of emitting a
warning and providing alternative behaviour.
The original "hack" implementing alternative behaviour was added
in #73345.
The lint was added in #83127.
The tracking issue is #83125.
The direct motivation for the change is that providing the alternative
behaviour is interfering with #125174 and follow-on work.
Rollup of 4 pull requests
Successful merges:
- #125339 (The number of tests does not depend on the architecture's pointer width)
- #125542 (Migrate rustdoc verify output files)
- #125616 (MIR validation: ensure that downcast projection is followed by field projection)
- #125625 (Use grep to implement verify-line-endings)
Failed merges:
- #125573 (Migrate `run-make/allow-warnings-cmdline-stability` to `rmake.rs`)
r? `@ghost`
`@rustbot` modify labels: rollup
This replaces the drop_in_place reference with null in vtables. On
librustc_driver.so, this drops about ~17k dynamic relocations from the
output, since many vtables can now be placed in read-only memory, rather
than having a relocated pointer included.
This makes a tradeoff by adding a null check at vtable call sites.
That's hard to avoid without changing the vtable format (e.g., to use a
pc-relative relocation instead of an absolute address, and avoid the
dynamic relocation that way). But it seems likely that the check is
cheap at runtime.
rustdoc: Clarify const-stability with regard to normal stability
Fixes#125511.
- Elide const-unstable if also unstable overall
- Show "const" for const-unstable if also overall unstable
drop region constraints for ambiguous goals
See the comment in `compute_external_query_constraints`. While the underlying issue is preexisting, this fixes a bug introduced by #125343.
It slightly weakens the leak chec, even if we didn't have any test which was affected. I want to write such a test before merging this PR.
r? `@compiler-errors`
[perf] Delay the construction of early lint diag structs
Attacks some of the perf regressions from https://github.com/rust-lang/rust/pull/124417#issuecomment-2123700666.
See individual commits for details. The first three commits are not strictly necessary.
However, the 2nd one (06bc4fc671, *Remove `LintDiagnostic::msg`*) makes the main change way nicer to implement.
It's also pretty sweet on its own if I may say so myself.
Remove `DefId` from `EarlyParamRegion`
Currently we represent usages of `Region` parameters via the `ReEarlyParam` or `ReLateParam` variants. The `ReEarlyParam` is effectively equivalent to `TyKind::Param` and `ConstKind::Param` (i.e. it stores a `Symbol` and a `u32` index) however it also stores a `DefId` for the definition of the lifetime parameter.
This was used in roughly two places:
- Borrowck diagnostics instead of threading the appropriate `body_id` down to relevant locations. Interestingly there were already some places that had to pass down a `DefId` manually.
- Some opaque type checking logic was using the `DefId` field to track captured lifetimes
I've split this PR up into a commit for generate rote changes to diagnostics code to pass around a `DefId` manually everywhere, and another commit for the opaque type related changes which likely require more careful review as they might change the semantics of lints/errors.
Instead of manually passing the `DefId` around everywhere I previously tried to bundle it in with `TypeErrCtxt` but ran into issues with some call sites of `infcx.err_ctxt` being unable to provide a `DefId`, particularly places involved with trait solving and normalization. It might be worth investigating adding some new wrapper type to pass this around everywhere but I think this might be acceptable for now.
This pr also has the effect of reducing the size of `EarlyParamRegion` from 16 bytes -> 8 bytes. I wouldn't expect this to have any direct performance improvement however, other variants of `RegionKind` over `8` bytes are all because they contain a `BoundRegionKind` which is, as far as I know, mostly there for diagnostics. If we're ever able to remove this it would shrink the `RegionKind` type from `24` bytes to `12` (and with clever bit packing we might be able to get it to `8` bytes). I am curious what the performance impact would be of removing interning of `Region`'s if we ever manage to shrink `RegionKind` that much.
Sidenote: by removing the `DefId` the `Debug` output for `Region` has gotten significantly nicer. As an example see this opaque type debug print before vs after this PR:
`Opaque(DefId(0:13 ~ impl_trait_captures[aeb9]::foo::{opaque#0}), [DefId(0:9 ~ impl_trait_captures[aeb9]::foo::'a)_'a/#0, T, DefId(0:9 ~ impl_trait_captures[aeb9]::foo::'a)_'a/#0])`
`Opaque(DefId(0:13 ~ impl_trait_captures[aeb9]::foo::{opaque#0}), ['a/#0, T, 'a/#0])`
r? `@compiler-errors` (I would like someone who understands the opaque type setup to atleast review the type system commit, but the rest is likely reviewable by anyone)
If a const function is unstable overall (and thus, in all circumstances
I know of, also const-unstable), we should show the option to use it as
const. You need to enable a feature to use the function at all anyway.
If the function is stabilized without also being const-stabilized, then
we do not show the const keyword and instead show "const: unstable" in
the version info.
Don't skip out of inner const when looking for body for suggestion
Self-explanatory title, I'll point out the important logic in an inline comment.
Fixes#125370
Don't continue probing for method if in suggestion and autoderef hits ambiguity
The title is somewhat self-explanatory. When we hit ambiguity in method autoderef steps, we previously would continue to probe for methods if we were giving a suggestion. This seems useless, and causes an ICE when we are not able to unify the receiver later on in confirmation.
Fixes#125432
Support C23's Variadics Without a Named Parameter
Fixes#123773
This PR removes the static check that disallowed extern functions
with ellipsis (varargs) as the only parameter since this is now
valid in C23.
This will not break any existing code as mentioned in the proposal
document: https://www.open-std.org/jtc1/sc22/wg14/www/docs/n2975.pdf.
Also, adds a doc comment for `check_decl_cvariadic_pos()` and
fixes the name of the function (`varadic` -> `variadic`).
