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`).
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.
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`
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.
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.
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()`.
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.
Support forwarding caller location through trait object method call
Since PR #69251, the `#[track_caller]` attribute has been supported on
traits. However, it only has an effect on direct (monomorphized) method
calls. Calling a `#[track_caller]` method on a trait object will *not*
propagate caller location information - instead, `Location::caller()` will
return the location of the method definition.
This PR forwards caller location information when `#[track_caller]` is
present on the method definition in the trait. This is possible because
`#[track_caller]` in this position is 'inherited' by any impls of that
trait, so all implementations will have the same ABI.
This PR does *not* change the behavior in the case where
`#[track_caller]` is present only on the impl of a trait.
While all implementations of the method might have an explicit
`#[track_caller]`, we cannot know this at codegen time, since other
crates may have impls of the trait. Therefore, we keep the current
behavior of not forwarding the caller location, ensuring that all
implementations of the trait will have the correct ABI.
See the modified test for examples of how this works
only check cg defaults wf once instantiated
the previous fixmes here didn't make too much sense as I didn't yet fully understand the code further below.
That code only runs if the predicates using our generic param default are fully concrete after substituting our default, which never happens if our default is generic.
r? `@oli-obk` `@BoxyUwU`
Remove `missing_docs` lint on private 2.0 macros
798baebde1/compiler/rustc_lint/src/builtin.rs (L573-L584)
This code is the source of #57569. The problem is subtle, so let me point it out. This code makes the mistake of assuming that all of the macros in `krate.exported_macros` are exported.
...Yeah. For some historical reason, all `macro` macros are marked as exported, regardless of whether they actually are, which is dreadfully confusing. It would be more accurate to say that `exported_macros` currently contains only macros that have paths.
This PR renames `exported_macros` to `importable_macros`, since these macros can be imported with `use` while others cannot. It also fixes the code above to no longer lint on private `macro` macros, since the `missing_docs` lint should only appear on exported items.
Fixes#57569.
Add support for raw-dylib with stdcall, fastcall functions
Next stage of work for #58713: allow `extern "stdcall"` and `extern "fastcall"` with `#[link(kind = "raw-dylib")]`.
I've deliberately omitted support for vectorcall, as that doesn't currently work, and I wanted to get this out for review. (I haven't really investigated the vectorcall failure much yet, but at first (very cursory) glance it appears that the problem is elsewhere.)
Use #[track_caller] in const panic diagnostics.
This change stops const panic diagnostics from reporting inside #[track_caller] functions by skipping over them.
Change linked tracking issue for more_qualified_paths
This updates the linked tracking issue for the `more_qualified_paths` feature from the implementation PR #80080 to an actual tracking issue #86935.
