RFC2229: Use the correct place type
Closes https://github.com/rust-lang/rust/issues/87097
The ICE occurred because instead of looking at the type of the place after all the projections are applied, we instead looked at the `base_ty` of the Place to decide whether a discriminant should be read of not. This lead to two issues:
1. the kind of the type is not necessarily `Adt` since we only look at the `base_ty`, it could be instead `Ref` for example
2. if the kind of the type is `Adt` you could still be looking at the wrong variant to make a decision on whether the discriminant should be read or not
r? `@nikomatsakis`
Replace associated item bound vars with placeholders when projecting
Fixes#76407Fixes#76826
Similar, but more limited, to #85499. This allows us to handle things like `for<'a> <T as Trait>::Assoc<'a>` but not `for<'a> <T as Trait<'a>>::Assoc`, unblocking GATs.
r? `@nikomatsakis`
Add -Zfuture-incompat-test to assist with testing future-incompat reports.
This adds a `-Zfuture-incompat-test` cli flag to assist with testing future-incompatible reports. This flag causes all lints to be treated as a future-incompatible lint, and will emit a report for them. This is being added so that Cargo's testsuite can reliably test the reporting infrastructure. Right now, Cargo relies on using array_into_iter as a test subject. Since the breaking "future incompatible" lints are never intended to last forever, this means Cargo's testsuite would always need to keep changing to choose different lints (for example, #86330 proposed dropping that moniker for array_into_iter). With this flag, Cargo's tests can trigger any lint and check for the report.
Reuse CrateNum for proc-macro crates even when cross-compiling
Proc-macros are always compiled for the host, so this should be the same
in every way as recompiling the crate.
I am not sure why the previous code special-cased the target, since the
compiler properly gives an error when trying to load a crate for a
different host:
```
error[E0461]: couldn't find crate `dependency` with expected target triple x86_64-unknown-linux-gnu
--> /home/joshua/rustc4/src/test/ui/cfg-dependent.rs:8:2
|
LL | dependency::is_64();
| ^^^^^^^^^^
|
= note: the following crate versions were found:
crate `dependency`, target triple i686-unknown-linux-gnu: /home/joshua/rustc4/build/x86_64-unknown-linux-gnu/test/ui/cfg-dependent/auxiliary/libdependency.so
```
I think another possible fix is to remove the check altogether. But I'm
not sure, and this fix works, so I'm not making the larger change here.
Fixes https://github.com/rust-lang/rust/issues/56935.
r? `@petrochenkov` cc `@alexcrichton`
Proc-macros are always compiled for the host, so this should be the same
in every way as recompiling the crate.
I am not sure why the previous code special-cased the target, since the
compiler properly gives an error when trying to load a crate for a
different host:
```
error[E0461]: couldn't find crate `dependency` with expected target triple x86_64-unknown-linux-gnu
--> /home/joshua/rustc4/src/test/ui/cfg-dependent.rs:8:2
|
LL | dependency::is_64();
| ^^^^^^^^^^
|
= note: the following crate versions were found:
crate `dependency`, target triple i686-unknown-linux-gnu: /home/joshua/rustc4/build/x86_64-unknown-linux-gnu/test/ui/cfg-dependent/auxiliary/libdependency.so
```
I think another possible fix is to remove the check altogether. But I'm
not sure, and this fix works, so I'm not making the larger change here.
expand: Support helper attributes for built-in derive macros
This is needed for https://github.com/rust-lang/rust/pull/86735 (derive macro `Default` should have a helper attribute `default`).
With this PR we can specify helper attributes for built-in derives using syntax `#[rustc_builtin_macro(MacroName, attributes(attr1, attr2, ...))]` which mirrors equivalent syntax for proc macros `#[proc_macro_derive(MacroName, attributes(attr1, attr2, ...))]`.
Otherwise expansion infra was already ready for this.
The attribute parsing code is shared between proc macro derives and built-in macros (`fn parse_macro_name_and_helper_attrs`).
This resolves all the problems we had around "normalizing" the representation of a Scalar in case it carries a Pointer value: we can just use Pointer if we want to have a value taht we are sure is already normalized.
Handle non-integer const generic parameters in debuginfo type names.
This PR fixes an ICE introduced by https://github.com/rust-lang/rust/pull/85269 which started emitting const generic arguments for debuginfo names but did not cover the case where such an argument could not be evaluated to a flat string of bits.
The fix implemented in this PR is very basic: If `try_eval_bits()` fails for the constant in question, we fall back to generating a stable hash of the constant and emit that instead. This way we get a (virtually) unique name and side step the problem of generating a string representation of a potentially complex value.
The downside is that the generated name will be rather opaque. E.g. the regression test adds a function `const_generic_fn_non_int<()>` which is then rendered as `const_generic_fn_non_int<{CONST#fe3cfa0214ac55c7}>`. I think it's an open question how to deal with this more gracefully.
I'd be interested in ideas on how to do this better.
r? `@wesleywiser`
cc `@dpaoliello` (do you see any problems with this approach?)
cc `@Mark-Simulacrum` & `@nagisa` (who I've seen comment on debuginfo issues recently -- anyone else?)
Fixes https://github.com/rust-lang/rust/issues/86893
Rollup of 6 pull requests
Successful merges:
- #87085 (Search result colors)
- #87090 (Make BTreeSet::split_off name elements like other set methods do)
- #87098 (Unignore some pretty printing tests)
- #87099 (Upgrade `cc` crate to 1.0.69)
- #87101 (Suggest a path separator if a stray colon is found in a match arm)
- #87102 (Add GUI test for "go to first" feature)
Failed merges:
r? `@ghost`
`@rustbot` modify labels: rollup
Avoid cloning ExpnData to access Span edition
ExpnData is a fairly hefty structure to clone; cloning it may not be cheap. In
some cases this may get optimized out, but it's not clear that will always be
the case. Try to avoid that cost.
r? `@ghost` -- opening for a perf run to start with
Fix internal `default_hash_types` lint to use resolved path
I run into false positives now and then (mostly in Clippy) when I want to name some util after HashMap.
ExpnData is a fairly hefty structure to clone; cloning it may not be cheap. In
some cases this may get optimized out, but it's not clear that will always be
the case. Try to avoid that cost.
target abi
Implement cfg(target_abi) (RFC 2992)
Add an `abi` field to `TargetOptions`, defaulting to "". Support using
`cfg(target_abi = "...")` for conditional compilation on that field.
Gated by `feature(cfg_target_abi)`.
Add a test for `target_abi`, and a test for the feature gate.
Add `target_abi` to tidy as a platform-specific cfg.
Update targets to use `target_abi`
All eabi targets have `target_abi = "eabi".`
All eabihf targets have `target_abi = "eabihf"`.
`armv6_unknown_freebsd` and `armv7_unknown_freebsd` have `target_abi = "eabihf"`.
All abi64 targets have `target_abi = "abi64"`.
All ilp32 targets have `target_abi = "ilp32"`.
All softfloat targets have `target_abi = "softfloat"`.
All *-uwp-windows-* targets have `target_abi = "uwp"`.
All spe targets have `target_abi = "spe"`.
All macabi targets have `target_abi = "macabi"`.
aarch64-apple-ios-sim has `target_abi = "sim"`.
`x86_64-fortanix-unknown-sgx` has `target_abi = "fortanix"`.
`x86_64-unknown-linux-gnux32` has `target_abi = "x32"`.
Add FIXME entries for targets for which existing values need to change
once `cfg_target_abi` becomes stable. (All of them are tier 3 targets.)
Add a test for `target_abi` in `--print cfg`.
Implement Mutation- and BorrowOfLayoutConstrainedField in thir-unsafeck
Since nobody has so far claimed Mutation- and BorrowOfLayoutConstrainedField in rust-lang/project-thir-unsafeck#7, I have taken the liberty of implementing them in thir-unsafeck.
r? `@LeSeulArtichaut`
CTFE engine: small cleanups
I noticed these while preparing a large PR, and figured I'd better send them ahead to not muddy the diff unnecessarily.
- remove remaining use of Pointer in Allocation API (I missed those in https://github.com/rust-lang/rust/pull/85472)
- remove unnecessary deallocate_local hack (this logic does not seem necessary any more)
r? `@oli-obk`
Simplify future incompatible reporting.
This simplifies the implementation of the future incompatible reporting system. Instead of having a separate field in the future_incompatible definition, this reuses the `FutureIncompatibilityReason` enum. It also drops the "date" field. Cargo does not use the date field, and there isn't much of a need for this to be structured, and I am skeptical that the date can be predicted reliably. The date or release version can be listed in the lint text if desired.
Fix ICE with unsized type in const pattern
Fixes#87046. The `deref_const()` query currently contains the following check:
e9a387d6cf/compiler/rustc_mir/src/const_eval/mod.rs (L191-L204)
i.e. this will cause an ICE for every unsized type except slices. An error is reported with my changes if such a type is used as a const pattern (this should not be a breaking change, since so far, this has caused an ICE).
Improve error reporting for modifications behind `&` references
I had a look at #84210 and noticed that #85823 has effectively already fixed#84210.
However, the string matching in #85823 is _very_ crude and already breaks down when a variable name starts with `mut`. I have made this a bit more robust; further improvements could definitely be made but are complicated by the lack of information provided by an earlier pass:
ce331ee6ee/compiler/rustc_mir_build/src/build/matches/mod.rs (L2103-L2107)
I have also fixed a missing comma in the error message.
Report an error if resolution of closure call functions failed
This pull request fixes#86238. The current implementation seems to assume that resolution of closure call functions (I'm not sure what the proper term is; I mean `call` of `Fn` etc.) can never fail:
60f1a2fc4b/compiler/rustc_typeck/src/check/callee.rs (L590-L595)
But actually, it can, if the `fn`/`fn_mut`/`fn_once` lang items are not defined, or don't have an associated `call`/`call_mut`/`call_once` function, leading to the ICE described in #86238. I have therefore turned the `span_bug!()` into an error message, which prevents the ICE.
Do not suggest adding a semicolon after `?`
Fixes#87051. I have only modified `report_return_mismatched_types()`, i.e. my changes only affect suggestions to add `;` for return type mismatches, but this never makes sense after `?`, because the function cannot return `()` if `?` is used (it has to return a `Result` or an `Option`), and a semicolon won't help if the expected and actual `Err` types differ, even if the expected one is `()`.
Stabilize "RangeFrom" patterns in 1.55
Implements a partial stabilization of #67264 and #37854.
Reference PR: https://github.com/rust-lang/reference/pull/900
# Stabilization Report
This stabilizes the `X..` pattern, shown as such, offering an exhaustive match for unsigned integers:
```rust
match x as u32 {
0 => println!("zero!"),
1.. => println!("positive number!"),
}
```
Currently if a Rust author wants to write such a match on an integer, they must use `1..={integer}::MAX` . By allowing a "RangeFrom" style pattern, this simplifies the match to not require the MAX path and thus not require specifically repeating the type inside the match, allowing for easier refactoring. This is particularly useful for instances like the above case, where different behavior on "0" vs. "1 or any positive number" is desired, and the actual MAX is unimportant.
Notably, this excepts slice patterns which include half-open ranges from stabilization, as the wisdom of those is still subject to some debate.
## Practical Applications
Instances of this specific usage have appeared in the compiler:
16143d1067/compiler/rustc_middle/src/ty/inhabitedness/mod.rs (L219)673d0db5e3/compiler/rustc_ty_utils/src/ty.rs (L524)
And I have noticed there are also a handful of "in the wild" users who have deployed it to similar effect, especially in the case of rejecting any value of a certain number or greater. It simply makes it much more ergonomic to write an irrefutable match, as done in Katholieke Universiteit Leuven's [SCALE and MAMBA project](05e5db00d5/WebAssembly/scale_std/src/fixed_point.rs (L685-L695)).
## Tests
There were already many tests in [src/test/ui/half-open-range/patterns](90a2e5e3fe/src/test/ui/half-open-range-patterns), as well as [generic pattern tests that test the `exclusive_range_pattern` feature](673d0db5e3/src/test/ui/pattern/usefulness/integer-ranges/reachability.rs), many dating back to the feature's introduction and remaining standing to this day. However, this stabilization comes with some additional tests to explore the... sometimes interesting behavior of interactions with other patterns. e.g. There is, at least, a mild diagnostic improvement in some edge cases, because before now, the pattern `0..=(5+1)` encounters the `half_open_range_patterns` feature gate and can thus emit the request to enable the feature flag, while also emitting the "inclusive range with no end" diagnostic. There is no intent to allow an `X..=` pattern that I am aware of, so removing the flag request is a strict improvement. The arrival of the `J | K` "or" pattern also enables some odd formations.
Some of the behavior tested for here is derived from experiments in this [Playground](https://play.rust-lang.org/?version=nightly&mode=debug&edition=2018&gist=58777b3c715c85165ac4a70d93efeefc) example, linked at https://github.com/rust-lang/rust/issues/67264#issuecomment-812770692, which may be useful to reference to observe the current behavior more closely.
In addition tests constituting an explanation of the "slicing range patterns" syntax issue are included in this PR.
## Desiderata
The exclusive range patterns and half-open range patterns are fairly strongly requested by many authors, as they make some patterns much more natural to write, but there is disagreement regarding the "closed" exclusive range pattern or the "RangeTo" pattern, especially where it creates "off by one" gaps in the presence of a "catch-all" wildcard case. Also, there are obviously no range analyses in place that will force diagnostics for e.g. highly overlapping matches. I believe these should be warned on, ideally, and I think it would be reasonable to consider such a blocker to stabilizing this feature, but there is no technical issue with the feature as-is from the purely syntactic perspective as such overlapping or missed matches can already be generated today with such a catch-all case. And part of the "point" of the feature, at least from my view, is to make it easier to omit wildcard matches: a pattern with such an "open" match produces an irrefutable match and does not need the wild card case, making it easier to benefit from exhaustiveness checking.
## History
- Implemented:
- Partially via exclusive ranges: https://github.com/rust-lang/rust/pull/35712
- Fully with half-open ranges: https://github.com/rust-lang/rust/pull/67258
- Unresolved Questions:
- The precedence concerns of https://github.com/rust-lang/rust/pull/48501 were considered as likely requiring adjustment but probably wanting a uniform consistent change across all pattern styles, given https://github.com/rust-lang/rust/issues/67264#issuecomment-720711656, but it is still unknown what changes might be desired
- How we want to handle slice patterns in ranges seems to be an open question still, as witnessed in the discussion of this PR!
I checked but I couldn't actually find an RFC for this, and given "approved provisionally by lang team without an RFC", I believe this might require an RFC before it can land? Unsure of procedure here, on account of this being stabilizing a subset of a feature of syntax.
r? `@scottmcm`
Improves migrations lint for RFC2229
This PR improves the current disjoint capture migration lint by providing more information on why drop order or auto trait implementation for a closure is impacted by the use of the new feature.
The drop order migration lint will now look something like this:
```
error: changes to closure capture in Rust 2021 will affect drop order
--> $DIR/significant_drop.rs:163:21
|
LL | let c = || {
| ^^
...
LL | tuple.0;
| ------- in Rust 2018, closure captures all of `tuple`, but in Rust 2021, it only captures `tuple.0`
...
LL | }
| - in Rust 2018, `tuple` would be dropped here, but in Rust 2021, only `tuple.0` would be dropped here alongside the closure
```
The auto trait migration lint will now look something like this:
```
error: changes to closure capture in Rust 2021 will affect `Send` trait implementation for closure
--> $DIR/auto_traits.rs:14:19
|
LL | thread::spawn(move || unsafe {
| ^^^^^^^^^^^^^^ in Rust 2018, this closure would implement `Send` as `fptr` implements `Send`, but in Rust 2021, this closure would no longer implement `Send` as `fptr.0` does not implement `Send`
...
LL | *fptr.0 = 20;
| ------- in Rust 2018, closure captures all of `fptr`, but in Rust 2021, it only captures `fptr.0`
```
r? `@nikomatsakis`
Closes https://github.com/rust-lang/project-rfc-2229/issues/54
Add clobber-only register classes for asm!
These are needed to properly express a function call ABI using a clobber
list, even though we don't support passing actual values into/out of
these registers.
- The `Rustc::expn_id` field kept redundant information
- `SyntaxContext` is no longer thrown away before `save_proc_macro_span` because it's thrown away during metadata encoding anyway
Improve opaque pointers support
Opaque pointers are coming, and rustc is not ready.
This adds partial support by passing an explicit load type to LLVM. Two issues I've encountered:
* The necessary type was not available at the point where non-temporal copies were generated. I've pushed the code for that upwards out of the memcpy implementation and moved the position of a cast to make do with the types we have available. (I'm not sure that cast is needed at all, but have retained it in the interest of conservativeness.)
* The `PlaceRef::project_deref()` function used during debuginfo generation seems to be buggy in some way -- though I haven't figured out specifically what it does wrong. Replacing it with `load_operand().deref()` did the trick, but I don't really know what I'm doing here.
remove const_raw_ptr_to_usize_cast feature
This feature currently has the strange status of "const-only `unsafe`", which was an experiment that we no longer think is a good idea. We need to find better ways to enable things like "messing with the low bits of a pointer" during CTFE.
r? `@oli-obk`
Fix several ICEs related to malformed `#[repr(...)]` attributes
This PR fixes#83921. #83921 actually contains two related but distinct issues (one of them incorrectly reported as a duplicate in https://github.com/rust-lang/rust/issues/83921#issuecomment-814640734):
In the first, a call to `delay_span_bug` leads to an ICE when compiling with `-Zunpretty=everybody_loops` (and some other pretty-printing modes), because the corresponding error is emitted in a later pass, which does not run when only pretty-printing is requested.
The second issue is about parsing `#[repr(...)]` attributes. Currently, all of the following cause an ICE when applied to a struct/enum:
```rust
#[repr(packed())]
#[repr(align)]
#[repr(align(2, 4))]
#[repr(align())]
#[repr(i8())]
#[repr(u32(42))]
#[repr(i64 = 2)]
```
I have fixed this by expanding the well-formedness checks in `find_repr_attrs()`.
Revert the revert of renaming traits::VTable to ImplSource
As #72114 and #73055 were merged so closely together I think this
accidentally happened while rebasing
These are needed to properly express a function call ABI using a clobber
list, even though we don't support passing actual values into/out of
these registers.
