fix false negative for `unused_mut`
fixes https://github.com/rust-lang/rust/issues/110849
We want to avoid double diagnostics for code like this, but only if an error actually occurs:
```rust
fn main() {
let mut x: (i32, i32);
x.0 = 1;
}
```
The first commit fixes the lint and the second one removes all the unused `mut`s it found.
Provide better type hints when a type doesn't support a binary operator
For example, when checking whether `vec![A] == vec![A]` holds, we first evaluate the LHS's ty, then probe for any `PartialEq` implementations for that. If none is found, we report an error by evaluating `Vec<A>: PartialEq<?0>` for fulfillment errors, but the RHS is not yet evaluated and remains an inference variable `?0`!
To fix this, we evaluate the RHS and equate it to that RHS infer var `?0`, so that we are able to provide more detailed fulfillment errors for why `Vec<A>: PartialEq<Vec<A>>` doesn't hold (namely, the nested obligation `A: PartialEq<A>` doesn't hold).
Fixes#95285Fixes#110867
Use MIR's `Offset` for pointer `add` too
~~Status: draft while waiting for #110822 to land, since this is built atop that.~~
~~r? `@ghost~~`
Canonical Rust code has mostly moved to `add`/`sub` on pointers, which take `usize`, instead of `offset` which takes `isize`. (And, relatedly, when `sub_ptr` was added it turned out it replaced every single in-tree use of `offset_from`, because `usize` is just so much more useful than `isize` in Rust.)
Unfortunately, `intrinsics::offset` could only accept `*const` and `isize`, so there's a *huge* amount of type conversions back and forth being done. They're identity conversions in the backend, but still end up producing quite a lot of unhelpful MIR.
This PR changes `intrinsics::offset` to accept `*const` *and* `*mut` along with `isize` *and* `usize`. Conveniently, the backends and CTFE already handle this, since MIR's `BinOp::Offset` [already supports all four combinations](adaac6b166/compiler/rustc_const_eval/src/transform/validate.rs (L523-L528)).
To demonstrate the difference, I added some `mir-opt/pre-codegen/` tests around slice indexing. Here's the difference to `[T]::get_mut`, since it uses `<*mut _>::add` internally:
```diff
`@@` -79,30 +70,21 `@@` fn slice_get_mut_usize(_1: &mut [u32], _2: usize) -> Option<&mut u32> {
StorageLive(_12); // scope 3 at $SRC_DIR/core/src/slice/index.rs:LL:COL
StorageLive(_9); // scope 6 at $SRC_DIR/core/src/slice/index.rs:LL:COL
_9 = _8 as *mut u32 (PtrToPtr); // scope 11 at $SRC_DIR/core/src/ptr/mut_ptr.rs:LL:COL
- StorageLive(_13); // scope 13 at $SRC_DIR/core/src/ptr/mut_ptr.rs:LL:COL
- _13 = _2 as isize (IntToInt); // scope 13 at $SRC_DIR/core/src/ptr/mut_ptr.rs:LL:COL
- StorageLive(_14); // scope 15 at $SRC_DIR/core/src/ptr/mut_ptr.rs:LL:COL
- StorageLive(_15); // scope 15 at $SRC_DIR/core/src/ptr/mut_ptr.rs:LL:COL
- _15 = _9 as *const u32 (Pointer(MutToConstPointer)); // scope 15 at $SRC_DIR/core/src/ptr/mut_ptr.rs:LL:COL
- _14 = Offset(move _15, _13); // scope 15 at $SRC_DIR/core/src/ptr/mut_ptr.rs:LL:COL
- StorageDead(_15); // scope 15 at $SRC_DIR/core/src/ptr/mut_ptr.rs:LL:COL
- _7 = move _14 as *mut u32 (PtrToPtr); // scope 15 at $SRC_DIR/core/src/ptr/mut_ptr.rs:LL:COL
- StorageDead(_14); // scope 15 at $SRC_DIR/core/src/ptr/mut_ptr.rs:LL:COL
- StorageDead(_13); // scope 13 at $SRC_DIR/core/src/ptr/mut_ptr.rs:LL:COL
+ _7 = Offset(_9, _2); // scope 13 at $SRC_DIR/core/src/ptr/mut_ptr.rs:LL:COL
StorageDead(_9); // scope 6 at $SRC_DIR/core/src/slice/index.rs:LL:COL
StorageDead(_12); // scope 3 at $SRC_DIR/core/src/slice/index.rs:LL:COL
StorageDead(_11); // scope 3 at $SRC_DIR/core/src/slice/index.rs:LL:COL
```
1c1c8e442a (diff-a841b6a4538657add3f39bc895744331453d0625e7aace128b1f604f0b63c8fdR80)
Add some missing built-in lints
(and also sort them, so this is best reviewed one commit at a time)
Fixes#110911
I wonder if there's a good way to detect when a lint is built-in (i.e. not associated to a lint pass). If so, it needs to be added to this list, or else we're unable to `allow` or `deny` it. Leaving that for future work, I guess...
Migrate trivially translatable `rustc_parse` diagnostics
cc #100717
Migrate diagnostics in `rustc_parse` which are emitted in a single statement. I worked on this by expanding the lint introduced in #108760, although that isn't included here as there is much more work to be done to satisfy it
More core::fmt::rt cleanup.
- Removes the `V1` suffix from the `Argument` and `Flag` types.
- Moves more of the format_args lang items into the `core::fmt::rt` module. (The only remaining lang item in `core::fmt` is `Arguments` itself, which is a public type.)
Part of https://github.com/rust-lang/rust/issues/99012
Follow-up to https://github.com/rust-lang/rust/pull/110616
Make `method-not-found-generic-arg-elision.rs` error message not path dependent
Every time I bless `tests/ui/methods/method-not-found-generic-arg-elision.rs`, I get some nonsense "type is too long" + "written to disk" that shows up and have to manually revert because the combination of my rustc repo path + the UI test directory hits the length limit for printing types spilling to disk (since this happens before UI test path sanitization).
The fact that we use a closure in this test doesn't have to do with the UI test, so just box the closure to make the type name smaller and not path dependent.
Fixes#35785 by converting non UTF-8 linker output to Unicode using the OEM code page.
Before:
```text
= note: Non-UTF-8 output: LINK : fatal error LNK1181: cannot open input file \'m\x84rchenhaft.obj\'\r\n
```
After:
```text
= note: LINK : fatal error LNK1181: cannot open input file 'märchenhaft.obj'
```
The difference is more dramatic if using a non-ascii language pack for Visual Studio.
Restructure and rename std thread_local internals to make it less of a maze
Every time I try to work on std's thread local internals, it feels like I'm trying to navigate a confusing maze made of macros, deeply nested modules, and types with multiple names/aliases. Time to clean it up a bit.
This PR:
- Exports `Key` with its own name (`Key`), instead of `__LocalKeyInner`
- Uses `pub macro` to put `__thread_local_inner` into a (unstable, hidden) module, removing `#[macro_export]`, removing it from the crate root.
- Removes the `__` from `__thread_local_inner`.
- Removes a few unnecessary `allow_internal_unstable` features from the macros
- Removes the `libstd_thread_internals` feature. (Merged with `thread_local_internals`.)
- And removes it from the unstable book
- Gets rid of the deeply nested modules for the `Key` definitions (`mod fast` / `mod os` / `mod statik`).
- Turns a `#[cfg]` mess into a single `cfg_if`, now that there's no `#[macro_export]` anymore that breaks with `cfg_if`.
- Simplifies the `cfg_if` conditions to not repeat the conditions.
- Removes useless `normalize-stderr-test`, which were left over from when the `Key` types had different names on different platforms.
- Removes a seemingly unnecessary `realstd` re-export on `cfg(test)`.
This PR changes nothing about the thread local implementation. That's for a later PR. (Which should hopefully be easier once all this stuff is a bit cleaned up.)
Add regression tests for const-generic inherent associated types
Fixes#109759.
The tests are no longer failing since #96840 which was merged recently (#109410 is no longer necessary for them).
`@rustbot` label F-inherent_associated_types
Replace `yes` command by `while-echo` in test `tests/ui/process/process-sigpipe.rs`
The `yes` command is not available on all platforms.
Fixes#108596.
Inviting `@mvf` as he contributed to this patch. Thanks! This issue has been discussed in https://github.com/rust-lang/rust/pull/106673 but was moved to #108596 to get going.
CC `@gh-tr`
r? `@workingjubilee`
`@rustbot` label +O-neutrino
Notes about the comments https://github.com/rust-lang/rust/pull/106673#discussion_r1117324265:
- The `echo` command is `/proc/boot/echo` (not built-in)
- `/bin/sh` is a symlink to `/proc/boot/ksh`
```sh
# ls -l /bin/sh /proc/boot/ksh /proc/boot/echo
lrwxrwxrwx 1 root root 14 Mar 20 07:52 /bin/sh -> /proc/boot/ksh
-r-xr-xr-x 1 root root 9390 Sep 12 2022 /proc/boot/echo
-r-xr-xr-x 1 root root 308114 Sep 12 2022 /proc/boot/ksh
```
Use `?0` notation for ty/ct/int/float/region vars
Aligns the notation for infer vars that T-types and friends most often uses for inference variables with the notation in the compiler (which is kinda a sigil nightmare IMO: `_#`) by adopting `?0` style infer vars.
This mostly affects debug output since verbose infer vars shouldn't show up in user-facing places.
Does this need an MCP? It's debug output, so I'm thinking no, but happy to open one. 🤔
r? types
Consider polarity in new solver
It's kinda ugly to have a polarity check in all of the builtin impls -- I guess I could consider the polarity at the top of assemble-builtin but that would require adding a polarity fn to `GoalKind`...
🤷 putting this up just so i dont forget, since it's needed to bootstrap core during coherence (this alone does not allow core to bootstrap though, additional work is needed!)
r? ``@lcnr``
Run various queries from other queries instead of explicitly in phases
These are just legacy leftovers from when rustc didn't have a query system. While there are more cleanups of this sort that can be done here, I want to land them in smaller steps.
This phased order of query invocations was already a lie, as any query that looks at types (e.g. the wf checks run before) can invoke e.g. const eval which invokes borrowck, which invokes typeck, ...
Clone region var origins instead of taking them in borrowck
Fixes an issue with the new solver where reporting a borrow-checker error ICEs because it calls `InferCtxt::evaluate_obligation`.
This also removes a handful of unnecessary `tcx.infer_ctxt().build()` calls that are only there to mitigate this same exact issue, but with the old solver.
Fixescompiler-errors/next-solver-hir-issues#12.
----
This implements `@aliemjay's` solution where we just don't *take* the region constraints, but clone them. This potentially makes it easier to write a bug about taking region constraints twice or never at all, but again, not many folks are touching this code.
Report allocation errors as panics
OOM is now reported as a panic but with a custom payload type (`AllocErrorPanicPayload`) which holds the layout that was passed to `handle_alloc_error`.
This should be review one commit at a time:
- The first commit adds `AllocErrorPanicPayload` and changes allocation errors to always be reported as panics.
- The second commit removes `#[alloc_error_handler]` and the `alloc_error_hook` API.
ACP: https://github.com/rust-lang/libs-team/issues/192Closes#51540Closes#51245
Evaluate place expression in `PlaceMention`
https://github.com/rust-lang/rust/pull/102256 introduces a `PlaceMention(place)` MIR statement which keep trace of `let _ = place` statements from surface rust, but without semantics.
This PR proposes to change the behaviour of `let _ =` patterns with respect to the borrow-checker to verify that the bound place is live.
Specifically, consider this code:
```rust
let _ = {
let a = 5;
&a
};
```
This passes borrowck without error on stable. Meanwhile, replacing `_` by `_: _` or `_p` errors with "error[E0597]: `a` does not live long enough", [see playground](https://play.rust-lang.org/?version=stable&mode=debug&edition=2021&gist=c448d25a7c205dc95a0967fe96bccce8).
This PR *does not* change how `_` patterns behave with respect to initializedness: it remains ok to bind a moved-from place to `_`.
The relevant test is `tests/ui/borrowck/let_underscore_temporary.rs`. Crater check found no regression.
For consistency, this PR changes miri to evaluate the place found in `PlaceMention`, and report eventual dangling pointers found within it.
r? `@RalfJung`
Add offset_of! macro (RFC 3308)
Implements https://github.com/rust-lang/rfcs/pull/3308 (tracking issue #106655) by adding the built in macro `core::mem::offset_of`. Two of the future possibilities are also implemented:
* Nested field accesses (without array indexing)
* DST support (for `Sized` fields)
I wrote this a few months ago, before the RFC merged. Now that it's merged, I decided to rebase and finish it.
cc `@thomcc` (RFC author)
Allow to feed a value in another query's cache and remove `WithOptConstParam`
I used it to remove `WithOptConstParam` queries, as an example.
The idea is that a query (here `typeck(function)`) can write into another query's cache (here `type_of(anon const)`). The dependency node for `type_of` would depend on all the current dependencies of `typeck`.
There is still an issue with cycles: if `type_of(anon const)` is accessed before `typeck(function)`, we will still have the usual cycle. The way around this issue is to `ensure` that `typeck(function)` is called before accessing `type_of(anon const)`.
When replayed, we may the following cases:
- `typeck` is green, in that case `type_of` is green too, and all is right;
- `type_of` is green, `typeck` may still be marked as red (it depends on strictly more things than `type_of`) -> we verify that the saved value and the re-computed value of `type_of` have the same hash;
- `type_of` is red, then `typeck` is red -> it's the caller responsibility to ensure `typeck` is recomputed *before* `type_of`.
As `anon consts` have their own `DefPathData`, it's not possible to have the def-id of the anon-const point to something outside the original function, but the general case may have to be resolved before using this device more broadly.
There is an open question about loading from the on-disk cache. If `typeck` is loaded from the on-disk cache, the side-effect does not happen. The regular `type_of` implementation can go and fetch the correct value from the decoded `typeck` results, and the dep-graph will check that the hashes match, but I'm not sure we want to rely on this behaviour.
I specifically allowed to feed the value to `type_of` from inside a call to `type_of`. In that case, the dep-graph will check that the fingerprints of both values match.
This implementation is still very sensitive to cycles, and requires that we call `typeck(function)` before `typeck(anon const)`. The reason is that `typeck(anon const)` calls `type_of(anon const)`, which calls `typeck(function)`, which feeds `type_of(anon const)`, and needs to build the MIR so needs `typeck(anon const)`. The latter call would not cycle, since `type_of(anon const)` has been set, but I'd rather not remove the cycle check.
Substitute missing trait items suggestion correctly
Properly substitute missing item suggestions, so that when they reference generics from their parent trait they actually have the right time for the impl.
Also, some other minor tweaks like using `/* Type */` to signify a GAT's type is actually missing, and fixing generic arg suggestions for GATs in general.
fix lint regression in `non_upper_case_globals`
Fixes#110573
The issue also exists for inherent associated types (where I copied my impl from). `EarlyContext` is more involved to fix in this way, so I'll leave it be for now (note it's unstable so that's not urgent).
r? `@compiler-errors`
Implement `Neg` for signed non-zero integers.
Negating a non-zero integer currently requires unpacking to a primitive and re-wrapping. Since negation of non-zero signed integers always produces a non-zero result, it is safe to implement `Neg` for `NonZeroI{N}`.
The new `impl` is marked as stable because trait impls for two stable types can't be marked unstable.
See discussion on https://github.com/rust-lang/libs-team/issues/105 for additional context.
Negating a non-zero integer currently requires unpacking to a
primitive and re-wrapping. Since negation of non-zero signed
integers always produces a non-zero result, it is safe to
implement `Neg` for `NonZeroI{N}`.
The new `impl` is marked as stable because trait implementations
for two stable types can't be marked unstable.
Add suggestion to use closure argument instead of a capture on borrowck error
Fixes#109271
r? `@compiler-errors`
This should probably be refined a bit, but opening a PR so that I don't forget anything.
Support AIX-style archive type
Reading facility of AIX big archive has been supported by `object` since 0.30.0.
Writing facility of AIX big archive has already been supported by `ar_archive_writer`, but we need to bump the version to support the new archive type enum.
make `non_upper_case_globals` lint not report trait impls
We should not lint on trait `impl`s for `non_upper_case_globals`; the user doesn't have control over the name. This brings `non_upper_case_globals` into consistency with other `nonstandard_style` lints.
Fix no_std tests that load libc from the sysroot when download-rustc is enabled
There were a series of unfortunate interactions here. Here's an MCVE of the test this fixes (committed as `tests/ui/meta/no_std-extern-libc.rs`):
```rust
#![crate_type = "lib"]
#![no_std]
#![feature(rustc_private)]
extern crate libc;
```
Before, this would give an error about duplicate versions of libc:
```
error[E0464]: multiple candidates for `rlib` dependency `libc` found
--> fake-test-src-base/allocator/no_std-alloc-error-handler-default.rs:15:1
|
LL | extern crate libc;
| ^^^^^^^^^^^^^^^^^^
|
= note: candidate #1: /home/gh-jyn514/rust/build/aarch64-unknown-linux-gnu/stage2/lib/rustlib/aarch64-unknown-linux-gnu/lib/liblibc-358db1024b7d9957.rlib
= note: candidate #2: /home/gh-jyn514/rust/build/aarch64-unknown-linux-gnu/stage2/lib/rustlib/aarch64-unknown-linux-gnu/lib/liblibc-ebc478710122a279.rmeta
```
Both these versions were downloaded from CI, but one came from the `rust-std` component and one came from `rustc-dev`:
```
; tar -tf build/cache/f2d9a3d0771504f1ae776226a5799dcb4408a91a/rust-std-nightly-x86_64-unknown-linux-gnu.tar.xz | grep liblibc
rust-std-nightly-x86_64-unknown-linux-gnu/rust-std-x86_64-unknown-linux-gnu/lib/rustlib/x86_64-unknown-linux-gnu/lib/liblibc-68a2d9e195dd6ed2.rlib
; tar -tf build/cache/f2d9a3d0771504f1ae776226a5799dcb4408a91a/rustc-dev-nightly-x86_64-unknown-linux-gnu.tar.xz | grep liblibc
rustc-dev-nightly-x86_64-unknown-linux-gnu/rustc-dev/lib/rustlib/x86_64-unknown-linux-gnu/lib/liblibc-f226c9fbdd92a0fd.rmeta
```
The fix was to only copy files from `rust-std` unless a Step explicitly requests for the `rustc-dev` components to be available by calling `builder.ensure(compile::Rustc)`.
To avoid having to re-parse the `rustc-dev.tar.xz` tarball every time, which is quite slow, this adds a new `build/host/ci-rustc/.rustc-dev-contents` cache file which stores only the names of files we need to copy into the sysroot.
This also allows reverting the hack in https://github.com/rust-lang/rust/pull/110121; now that we only copy rustc-dev on-demand, we can correctly add the `Rustc` check artifacts into the sysroot, so that this works correctly even when `download-rustc` is forced to `true` and some tool depends on a local change to `compiler`.
---
See https://github.com/rust-lang/rust/issues/108767#issuecomment-1501217657 for why `no_std` is required for the MCVE test to fail; it's complicated and not particularly important.
Fixes https://github.com/rust-lang/rust/issues/108767.
There were a series of unfortunate interactions here. Here's an MCVE of the test this fixes (committed as `tests/ui/meta/no_std-extern-libc.rs`):
```rust
#![crate_type = "lib"]
#![no_std]
#![feature(rustc_private)]
extern crate libc;
```
Before, this would give an error about duplicate versions of libc:
```
error[E0464]: multiple candidates for `rlib` dependency `libc` found
--> fake-test-src-base/allocator/no_std-alloc-error-handler-default.rs:15:1
|
LL | extern crate libc;
| ^^^^^^^^^^^^^^^^^^
|
= note: candidate #1: /home/gh-jyn514/rust/build/aarch64-unknown-linux-gnu/stage2/lib/rustlib/aarch64-unknown-linux-gnu/lib/liblibc-358db1024b7d9957.rlib
= note: candidate #2: /home/gh-jyn514/rust/build/aarch64-unknown-linux-gnu/stage2/lib/rustlib/aarch64-unknown-linux-gnu/lib/liblibc-ebc478710122a279.rmeta
```
Both these versions were downloaded from CI, but one came from the `rust-std` component and one came from `rustc-dev`:
```
; tar -tf build/cache/f2d9a3d0771504f1ae776226a5799dcb4408a91a/rust-std-nightly-x86_64-unknown-linux-gnu.tar.xz | grep liblibc
rust-std-nightly-x86_64-unknown-linux-gnu/rust-std-x86_64-unknown-linux-gnu/lib/rustlib/x86_64-unknown-linux-gnu/lib/liblibc-68a2d9e195dd6ed2.rlib
; tar -tf build/cache/f2d9a3d0771504f1ae776226a5799dcb4408a91a/rustc-dev-nightly-x86_64-unknown-linux-gnu.tar.xz | grep liblibc
rustc-dev-nightly-x86_64-unknown-linux-gnu/rustc-dev/lib/rustlib/x86_64-unknown-linux-gnu/lib/liblibc-f226c9fbdd92a0fd.rmeta
```
The fix was to only copy files from `rust-std` unless a Step explicitly requests for the `rustc-dev` components to be available by calling `builder.ensure(compile::Rustc)`.
To avoid having to re-parse the `rustc-dev.tar.xz` tarball every time, which is quite slow, this adds a new `build/host/ci-rustc/.rustc-dev-contents` cache file which stores only the names of files we need to copy into the sysroot.
This also allows reverting the hack in
https://github.com/rust-lang/rust/pull/110121; now that we only copy
rustc-dev on-demand, we can correctly add the `Rustc` check artifacts
into the sysroot, so that this works correctly even when
`download-rustc` is forced to `true`.
---
See https://github.com/rust-lang/rust/issues/108767#issuecomment-1501217657 for why `no_std` is required for the MCVE test to fail; it's complicated and not particularly important.
Fixes https://github.com/rust-lang/rust/issues/108767.
Support `x test --stage 1 ui-fulldeps`
`@Nilstrieb` had an excellent idea the other day: the same way that rustdoc is able to load `rustc_driver` from the sysroot, ui-fulldeps tests should also be able to load it from the sysroot. That allows us to run fulldeps tests with stage1, without having to fully rebuild the compiler twice. It does unfortunately have the downside that we're building the tests with the *bootstrap* compiler, not the in-tree sources, but since most of the fulldeps tests are for the *API* of the compiler, that seems ok.
I think it's possible to extend this to `run-make-fulldeps`, but I've run out of energy for tonight.
- Move `plugin` tests into a subdirectory.
Plugins are loaded at runtime with `dlopen` and so require the ABI of the running compile to match the ABI of the compiler linked with `rustc_driver`. As a result they can't be supported in stage 1 and have to use `// ignore-stage1`.
- Remove `ignore-stage1` from most non-plugin tests
- Ignore diagnostic tests in stage 1. Even though this requires a stage 2 build to load rustc_driver, it's primarily testing the error message that the *running* compiler emits when the diagnostic struct is malformed.
- Pass `-Zforce-unstable-if-unmarked` in stage1, not just stage2. That allows running `hash-stable-is-unstable` in stage1, since it now suggests adding `rustc_private` to enable loading the crates.
- Add libLLVM.so to the stage0 target sysroot, to allow fulldeps tests that act as custom drivers to load it at runtime.
- Pass `--sysroot stage0-sysroot` in compiletest so that we use the correct version of std.
- Move a few lint tests from ui-fulldeps to ui
These had an `aux-build:lint-group-plugin-test.rs` that they never actually loaded with `feature(plugin)` nor tested. I removed the unused aux-build and they pass fine with stage 1.
Fixes https://github.com/rust-lang/rust/issues/75905.
Nils had an excellent idea the other day: the same way that rustdoc is
able to load `rustc_driver` from the sysroot, ui-fulldeps tests should
also be able to load it from the sysroot. That allows us to run fulldeps
tests with stage1, without having to fully rebuild the compiler twice.
It does unfortunately have the downside that we're running the tests on
the *bootstrap* compiler, not the in-tree sources, but since most of the
fulldeps tests are for the *API* of the compiler, that seems ok.
I think it's possible to extend this to `run-make-fulldeps`, but I've
run out of energy for tonight.
- Move `plugin` tests into a subdirectory.
Plugins are loaded at runtime with `dlopen` and so require the ABI of
the running compile to match the ABI of the compiler linked with
`rustc_driver`. As a result they can't be supported in stage 1 and have
to use `// ignore-stage1`.
- Remove `ignore-stage1` from most non-plugin tests
- Ignore diagnostic tests in stage 1. Even though this requires a stage
2 build to load rustc_driver, it's primarily testing the error message
that the *running* compiler emits when the diagnostic struct is malformed.
- Pass `-Zforce-unstable-if-unmarked` in stage1, not just stage2. That
allows running `hash-stable-is-unstable` in stage1, since it now
suggests adding `rustc_private` to enable loading the crates.
- Add libLLVM.so to the stage0 target sysroot, to allow fulldeps tests
that act as custom drivers to load it at runtime.
- Pass `--sysroot stage0-sysroot` in compiletest so that we use the
correct version of std.
Check freeze with right param-env in `deduced_param_attrs`
We're checking if a trait (`Freeze`) holds in a polymorphic function, but not using that function's own (reveal-all) param-env. This causes us to try to eagerly normalize a specializable projection type that has no default value, which causes an ICE.
Fixes#110171
Remove `remap_env_constness` in queries
This removes some of the complexities with const traits. #88119 used to be caused by this but was fixed by `param_env = param_env.without_const()`.
Update some ignored tests.
This unignores some tests which no longer need to be ignored (see individual commits for reasons why). This also adds some descriptions to why tests are ignored so they can be seen in the test output.
suggest lifetime for closure parameter type when mismatch
This is a draft PR, will add test cases later and be ready for review.
This PR fixes https://github.com/rust-lang/rust/issues/105675 by adding a diagnostics suggestion. Also a partial fix to https://github.com/rust-lang/rust/issues/105528.
The following code will have a compile error now:
```
fn const_if_unit(input: bool) -> impl for<'a> FnOnce(&'a ()) -> usize {
let x = |_| 1;
x
}
```
Before this PR:
```
error[E0308]: mismatched types
--> src/lib.rs:3:5
|
3 | x
| ^ one type is more general than the other
|
= note: expected trait `for<'a> FnOnce<(&'a (),)>`
found trait `FnOnce<(&(),)>`
note: this closure does not fulfill the lifetime requirements
--> src/lib.rs:2:13
|
2 | let x = |_| 1;
| ^^^
error: implementation of `FnOnce` is not general enough
--> src/lib.rs:3:5
|
3 | x
| ^ implementation of `FnOnce` is not general enough
|
= note: closure with signature `fn(&'2 ()) -> usize` must implement `FnOnce<(&'1 (),)>`, for any lifetime `'1`...
= note: ...but it actually implements `FnOnce<(&'2 (),)>`, for some specific lifetime `'2`
For more information about this error, try `rustc --explain E0308`.
error: could not compile `rust-test` due to 2 previous errors
```
After this PR:
```
error[E0308]: mismatched types
--> src/lib.rs:3:5
|
3 | x
| ^ one type is more general than the other
|
= note: expected trait `for<'a> FnOnce<(&'a (),)>`
found trait `FnOnce<(&(),)>`
note: this closure does not fulfill the lifetime requirements
--> src/lib.rs:2:13
|
2 | let x = |_| 1;
| ^^^
help: consider changing the type of the closure parameters
|
2 | let x = |_: &_| 1;
| ~~~~~~~
error: implementation of `FnOnce` is not general enough
--> src/lib.rs:3:5
|
3 | x
| ^ implementation of `FnOnce` is not general enough
|
= note: closure with signature `fn(&'2 ()) -> usize` must implement `FnOnce<(&'1 (),)>`, for any lifetime `'1`...
= note: ...but it actually implements `FnOnce<(&'2 (),)>`, for some specific lifetime `'2`
For more information about this error, try `rustc --explain E0308`.
error: could not compile `rust-test` due to 2 previous errors
```
After applying the suggestion, it compiles. The suggestion might not always be correct as the generation procedure of that suggestion is quite simple...
This test was ignored long ago in
https://github.com/rust-lang/rust/pull/20578/ when the syntax for
closures was changed.
The current status is that a closure with an explicit `!` return type
will trigger the `unreachable_code` lint which appears to be the
original intent of the test
(https://github.com/rust-lang/rust/pull/16836). A closure without a
return type won't trigger the lint since the `!` type isn't inferred
(AFAIK). This restores the test to its original form.
Do not attempt to commute comparison and cast to codegen discriminants
The general algorithm to compute a discriminant is:
```
relative_tag = tag - niche_start
is_niche = relative_tag <= (ule) relative_max
discr = if is_niche {
cast(relative_tag) + niche_variants.start()
} else {
untagged_variant
}
```
We have an optimization branch which attempts to merge the addition and the subtraction by commuting them with the cast. We currently get this optimization wrong.
This PR takes the easiest and safest way: remove the optimization, and let LLVM handle it. (Perf may not agree with that course of action 😅)
There may be a less invasive solution, but I don't have the necessary knowledge of LLVM semantics to find it. Cranelift has the same optimization, which should be handled similarly.
cc `@nikic` and `@bjorn3` if you have a better solution.
Fixes https://github.com/rust-lang/rust/issues/110128
Reformulate `point_at_expr_source_of_inferred_type` to be more accurate
Be more accurate when deducing where along the several usages of a binding it is constrained to be some type that is incompatible with an expectation.
This also renames the method to `note_source_of_type_mismatch_constraint` because I prefer that name, though I guess I can revert that. (Also drive-by rename `note_result_coercion` -> `suggest_coercing_result_via_try_operator`, because it's suggesting, not noting!)
This PR is (probably?) best reviewed per commit, but it does regress a bit only to fix it later on, so it could also be reviewed as a whole if that makes the final results more clear.
r? `@estebank`
Remove all but one of the spans in `BoundRegionKind::BrAnon`
There are only three places where `BoundRegionKind::BrAnon` uses `Some(span)` instead of `None`. Two of them are easy to remove, which this PR does.
r? ```@jackh726```
don't uniquify regions when canonicalizing
uniquifying causes a bunch of issues, most notably it causes `AliasEq(<?x as Trait<'a>>::Assoc, <?x as Trait<'a>>::Assoc)` to result in ambiguity because both `normalizes-to` paths result in ambiguity and substs equate should trivially succeed but doesn't because we uniquified `'a` to two different regions.
I originally added uniquification to make it easier to deal with requirement 6 from the dev-guide: https://rustc-dev-guide.rust-lang.org/solve/trait-solving.html#requirements
> ### 6. Trait solving must be (free) lifetime agnostic
>
> Trait solving during codegen should have the same result as during typeck. As we erase
> all free regions during codegen we must not rely on them during typeck. A noteworthy example
> is special behavior for `'static`.
cc https://github.com/rust-lang/rustc-dev-guide/pull/1671
Relying on regions being identical may cause ICE during MIR typeck, but even without this PR we can end up relying on that as type inference vars can resolve to types which contain an identical region. Let's land this and deal with any ICE that crop up as we go. Will look at this issue again before stabilization.
r? ```@compiler-errors```
Improve safe transmute error reporting
This patch updates the error reporting when Safe Transmute is not possible between 2 types by including the reason.
Also, fix some small bugs that occur when computing the `Answer` for transmutability.
The `std` test straightforwardly can't work without file descriptors;
#99417 tracks moving it out of tests/ui.
`issue-13560.rs` requires the target to support dynamic linking.
`extern-mod-syntax` is interesting. The original test was added to check
if `extern mod` could be parsed correctly and used `extern mod std` and
an import:
138dc3048a (diff-73700e1e851b7a37bc92174635dab726124c82e5bfabbbc45b4a3c2e8e14fadd)
At some point `std::json::Object` was moved out of std to an unstable
rustc-only `extras` crate, and rather than just changing the import it
got changed to use the unstable crate. When `extras` was removed, people
assumed the test was meant to also test rustc_private and changed it to
another unstable crate rather than using something in std.
This changes the test to remove the `rustc_private` import, to allow it
to work properly when cross-compiling.
This patch updates the error reporting when Safe Transmute is not
possible between 2 types by including the reason.
Also, fix some small bugs that occur when computing the `Answer` for
transmutability.
