Rescope temp lifetime in if-let into IfElse with migration lint
Tracking issue #124085
This PR shortens the temporary lifetime to cover only the pattern matching and consequent branch of a `if let`.
At the expression location, means that the lifetime is shortened from previously the deepest enclosing block or statement in Edition 2021. This warrants an Edition change.
Coming with the Edition change, this patch also implements an edition lint to warn about the change and a safe rewrite suggestion to preserve the 2021 semantics in most cases.
Related to #103108.
Related crater runs: https://github.com/rust-lang/rust/pull/129466.
Fix anon const def-creation when macros are involved
Fixes#128016.
Ever since #125915, some `ast::AnonConst`s turn into `hir::ConstArgKind::Path`s,
which don't have associated `DefId`s. To deal with the fact that we don't have
resolution information in `DefCollector`, we decided to implement a process
where if the anon const *appeared* to be trivial (i.e., `N` or `{ N }`), we
would avoid creating a def for it in `DefCollector`. If later, in AST lowering,
we realized it turned out to be a unit struct literal, or we were lowering it
to something that didn't use `hir::ConstArg`, we'd create its def there.
However, let's say we have a macro `m!()` that expands to a reference to a free
constant `FOO`. If we use `m!()` in the body of an anon const (e.g., `Foo<{ m!() }>`),
then in def collection, it appears to be a nontrivial anon const and we create
a def. But the macro expands to something that looks like a trivial const arg,
but is not, so in AST lowering we "fix" the mistake we assumed def collection
made and create a def for it. This causes a duplicate definition ICE.
The long-term fix for this is to delay the creation of defs for all expression-like
nodes until AST lowering (see #128844 for an incomplete attempt at this). This
would avoid issues like this one that are caused by hacky workarounds. However,
doing this uncovers a pre-existing bug with opaque types that is quite involved
to fix (see #129023).
In the meantime, this PR fixes the bug by delaying def creation for anon consts
whose bodies are macro invocations until after we expand the macro and know
what is inside it. This is accomplished by adding information to create the
anon const's def to the data in `Resolver.invocation_parents`.
r? `@BoxyUwU`
...and remove the `const_arg_path` feature gate as a result. It was only
a stopgap measure to fix the regression that the new lowering introduced
(which should now be fixed by this PR).
Ever since #125915, some `ast::AnonConst`s turn into `hir::ConstArgKind::Path`s,
which don't have associated `DefId`s. To deal with the fact that we don't have
resolution information in `DefCollector`, we decided to implement a process
where if the anon const *appeared* to be trivial (i.e., `N` or `{ N }`), we
would avoid creating a def for it in `DefCollector`. If later, in AST lowering,
we realized it turned out to be a unit struct literal, or we were lowering it
to something that didn't use `hir::ConstArg`, we'd create its def there.
However, let's say we have a macro `m!()` that expands to a reference to a free
constant `FOO`. If we use `m!()` in the body of an anon const (e.g., `Foo<{ m!() }>`),
then in def collection, it appears to be a nontrivial anon const and we create
a def. But the macro expands to something that looks like a trivial const arg,
but is not, so in AST lowering we "fix" the mistake we assumed def collection
made and create a def for it. This causes a duplicate definition ICE.
The ideal long-term fix for this is a bit unclear. One option is to delay def
creation for all expression-like nodes until AST lowering (see #128844 for an
incomplete attempt at this). This would avoid issues like this one that are
caused by hacky workarounds. However, this approach has some downsides as well,
and the best approach is yet to be determined.
In the meantime, this PR fixes the bug by delaying def creation for anon consts
whose bodies are macro invocations until after we expand the macro and know
what is inside it. This is accomplished by adding information to create the
anon const's def to the data in `Resolver.invocation_parents`.
more eagerly discard constraints on overflow
We always discard the results of overflowing goals inside of the trait solver. We previously did so when instantiating the response in `evaluate_goal`. Canonicalizing results only to later discard them is also inefficient 🤷
It's simpler and nicer to debug to eagerly discard constraints inside of the query itself.
r? ``@compiler-errors``
coverage: Simplify creation of sum counters
A small and self-contained improvement, extracted from some larger changes that I'm still working on.
Ultimately I want to avoid creating these sum counter-expressions in some cases (in favour of just adding physical counters directly to the nodes we care about), so a good incremental move towards that is splitting the “gather edge counters” step out from the ”build a sum of those counters” step.
Creating an extra intermediate vector should have negligible cost (and coverage isn't exercised by the benchmark suite anyway). The removed logging is redundant with the `#[instrument(..)]` logging we already have on the underlying method calls.
Introduce `'ra` lifetime name.
`rustc_resolve` allocates many things in `ResolverArenas`. The lifetime used for references into the arena is mostly `'a`, and sometimes `'b`.
This commit changes it to `'rslv`, which is much more descriptive. The commit also changes the order of lifetimes on a couple of structs so that '`rslv` is second last, before `'tcx`, and does other minor renamings such as `'r` to `'a`.
r? ``@petrochenkov``
cc ``@oli-obk``
some const cleanup: remove unnecessary attributes, add const-hack indications
I learned that we use `FIXME(const-hack)` on top of the "const-hack" label. That seems much better since it marks the right place in the code and moves around with the code. So I went through the PRs with that label and added appropriate FIXMEs in the code. IMO this means we can then remove the label -- Cc ``@rust-lang/wg-const-eval.``
I also noticed some const stability attributes that don't do anything useful, and removed them.
r? ``@fee1-dead``
Re-run coverage tests if `coverage-dump` was modified
If the `coverage-dump` tool was modified, coverage tests should not be treated as up-to-date, because the tool's output might have changed.
Bootstrap already handles rebuilding the tool itself if its sources were changed, so all compiletest needs to do here is include the binary in the list of files whose timestamps are checked.
This should have no effect on non-coverage tests, because bootstrap won't pass the `--coverage-dump-path` flag, so the path in compiletest's config will be None.
Properly report error on `const gen fn`
Fixes#130232
Also removes some (what I thought were unused) functions, and fixes a bug in clippy where we considered `gen fn` to be the same as `fn` because it was only built to consider asyncness.
Fix `clippy::useless_conversion`
Self-explanatory. Probably the last clippy change I'll actually put up since this is the only other one I've actually seen in the wild.
Simplify some nested `if` statements
Applies some but not all instances of `clippy::collapsible_if`. Some ended up looking worse afterwards, though, so I left those out. Also applies instances of `clippy::collapsible_else_if`
Review with whitespace disabled please.
Add test for S_OBJNAME & update test for LF_BUILDINFO cl and cmd
Update the unit test for checking cl and cmd in LF_BUILDINFO. With llvm-pdbutil we can now more specifically check if the string appears at the right location instead of just checking whether the string exists at all.
Context: https://github.com/rust-lang/rust/issues/96475
Fix default/minimum deployment target for Aarch64 simulator targets
The minimum that `rustc` encoded did not match [the version in Clang](https://github.com/llvm/llvm-project/blob/llvmorg-18.1.8/llvm/lib/TargetParser/Triple.cpp#L1900-L1932), and that meant that that when linking, Clang ended up bumping the version. See https://github.com/rust-lang/rust/issues/129432 for more motivation behind this change.
Specifically, this PR sets the correct deployment target of the following targets:
- `aarch64-apple-ios-sim` from 10.0 to 14.0
- `aarch64-apple-tvos-sim` from 10.0 to 14.0
- `aarch64-apple-watchos-sim` from 5.0 to 7.0
- `aarch64-apple-ios-macabi` from 13.1 to 14.0
I have chosen not to document the `-sim` changes in the platform support docs, as it is fundamentally uninteresting; the normal targets (e.g. `aarch64-apple-ios`) still have the same deployment target, and that's what developers should actually target.
r? compiler
CC `@BlackHoleFox`
Expand documentation of PathBuf, discussing lack of sanitization
Various methods in `PathBuf`, in particular `set_file_name` and `set_extension` accept strings which include path seperators (like `../../etc`). These methods just glue together strings, so you can end up with strange strings.
This isn't reasonable to change/fix at this point, and might not even be fixable, but I think should be documented. In particular, you probably shouldn't blindly build paths using strings given by possibly malicious users.
Pass deployment target when linking with CC on Apple targets
This PR effectively implements what's also being considered in the `cc` crate [here](https://github.com/rust-lang/cc-rs/issues/1030#issuecomment-2051020649), that is:
- When linking macOS targets with CC, pass the `-mmacosx-version-min=.` option to specify the desired deployment target. Also, no longer pass `-m32`/`-m64`, these are redundant since we already pass `-arch`.
- When linking with CC on iOS, tvOS, watchOS and visionOS, only pass `-target` (we assume for these targets that CC forwards to Clang).
This is required to get the linker to emit the correct `LC_BUILD_VERSION` of the final binary. See https://github.com/rust-lang/rust/issues/129432 for more motivation behind this change.
r? compiler
CC `@BlackHoleFox`
Add -Z small-data-threshold
This flag allows specifying the threshold size above which LLVM should not consider placing small objects in a `.sdata` or `.sbss` section.
Support is indicated in the target options via the
small-data-threshold-support target option, which can indicate either an
LLVM argument or an LLVM module flag. To avoid duplicate specifications
in a large number of targets, the default value for support is
DefaultForArch, which is translated to a concrete value according to the
target's architecture.
Limit `libc::link` usage to `nto70` target only, not NTO OS
It seems QNX 7.0 does not support `linkat` at all (most tests were failing). Limiting to QNX 7.0 only, while using `linkat` for the future versions seems like the right path forward (tested on 7.0).
Fixes#129895
CC: `@japaric` `@flba-eb` `@saethlin`
Use the same span for attributes and Try expansion of ?
This is needed for Clippy to know that the `#[allow(unused)]` attributes added by the expansion of `?` are part of the desugaring, and that they do not come from the user code.
rust-lang/rust-clippy#13380 exhibits a manifestation of this problem and will be fixed by this change.
miri: fix overflow detection for unsigned pointer offset
This is the Miri part of https://github.com/rust-lang/rust/pull/130229. This is already UB in codegen so we better make Miri detect it; updating the docs may take time if we have to follow some approval process, but let's make Miri match reality ASAP.
r? ``@scottmcm``
enable const-float-classify test, and test_next_up/down on 32bit x86
The test_next_up/down tests have been disabled on all 32bit x86 targets, which goes too far -- they should definitely work on our (tier 1) i686 target, it is only without SSE that we might run into trouble due to https://github.com/rust-lang/rust/issues/114479. However, I cannot reproduce that trouble any more -- maybe that got fixed by https://github.com/rust-lang/rust/pull/123351?
The const-float-classify test relied on const traits "because we can", and got disabled when const traits got removed. That's an unfortunate reduction in test coverage of our float functionality, so let's restore the test in a way that does not rely on const traits.
The const-float tests are actually testing runtime behavior as well, and I don't think that runtime behavior is covered anywhere else. Probably they shouldn't be called "const-float", but we don't have a `tests/ui/float` folder... should I create one and move them there? Are there any other ui tests that should be moved there?
I also removed some FIXME referring to not use x87 for Rust-to-Rust-calls -- that has happened in #123351 so this got fixed indeed. Does that mean we can simplify all that float code again? I am not sure how to test it. Is running the test suite with an i586 target enough?
Cc ```@tgross35``` ```@workingjubilee```
Don't warn empty branches unreachable for now
The [stabilization](https://github.com/rust-lang/rust/pull/122792) of `min_exhaustive_patterns` updated the `unreachable_pattern` lint to trigger on empty arms too. This has caused some amount of churn, and imposes an unjoyful `#[allow(unreachable_patterns)]` onto library authors who want to stay backwards-compatible.
While I think the lint should eventually cover these cases, for transition's sake I'd prefer to revert linting to what it was prior to stabilization, at least for now.
Fixes https://github.com/rust-lang/rust/issues/129031.
r? ``@compiler-errors``
`rustc_resolve` allocates many things in `ResolverArenas`. The lifetime
used for references into the arena is mostly `'a`, and sometimes `'b`.
This commit changes it to `'ra`, which is much more descriptive. The
commit also changes the order of lifetimes on a couple of structs so
that '`ra` is second last, before `'tcx`, and does other minor
renamings such as `'r` to `'a`.
It seems QNX 7.0 does not support `linkat` at all (most tests were failing). Limiting to QNX 7.0 only, while using `linkat` for the future versions seems like the right path forward (tested on 7.0).
Fixes 129895
bors