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Prevent generic pattern types from being used in libstd

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This commit is contained in:
Oli Scherer 2025-02-05 11:45:50 +00:00
parent 8df89d1cb0
commit fab6d8ae8c
7 changed files with 101 additions and 11 deletions
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2
compiler/rustc_feature/src/unstable.rs
View file

@ -507,6 +507,8 @@ declare_features! (
(incomplete, generic_const_exprs, "1.56.0", Some(76560)),
/// Allows generic parameters and where-clauses on free & associated const items.
(incomplete, generic_const_items, "1.73.0", Some(113521)),
/// Allows any generic constants being used as pattern type range ends
(incomplete, generic_pattern_types, "CURRENT_RUSTC_VERSION", Some(136574)),
/// Allows registering static items globally, possibly across crates, to iterate over at runtime.
(unstable, global_registration, "1.80.0", Some(125119)),
/// Allows using guards in patterns.

1
compiler/rustc_span/src/symbol.rs
View file

@ -1013,6 +1013,7 @@ symbols! {
generic_const_exprs,
generic_const_items,
generic_param_attrs,
generic_pattern_types,
get_context,
global_alloc_ty,
global_allocator,

44
compiler/rustc_trait_selection/src/traits/wf.rs
View file

@ -8,8 +8,9 @@ use rustc_middle::ty::{
self, GenericArg, GenericArgKind, GenericArgsRef, Ty, TyCtxt, TypeSuperVisitable,
TypeVisitable, TypeVisitableExt, TypeVisitor,
};
use rustc_span::Span;
use rustc_session::parse::feature_err;
use rustc_span::def_id::{DefId, LocalDefId};
use rustc_span::{Span, sym};
use tracing::{debug, instrument, trace};
use crate::infer::InferCtxt;
@ -704,8 +705,47 @@ impl<'a, 'tcx> TypeVisitor<TyCtxt<'tcx>> for WfPredicates<'a, 'tcx> {
));
}
ty::Pat(subty, _) => {
ty::Pat(subty, pat) => {
self.require_sized(subty, ObligationCauseCode::Misc);
match *pat {
ty::PatternKind::Range { start, end, include_end: _ } => {
let mut check = |c| {
let cause = self.cause(ObligationCauseCode::Misc);
self.out.push(traits::Obligation::with_depth(
tcx,
cause.clone(),
self.recursion_depth,
self.param_env,
ty::Binder::dummy(ty::PredicateKind::Clause(
ty::ClauseKind::ConstArgHasType(c, subty),
)),
));
if !tcx.features().generic_pattern_types() {
if c.has_param() {
if self.span.is_dummy() {
self.tcx().dcx().delayed_bug(
"feature error should be reported elsewhere, too",
);
} else {
feature_err(
&self.tcx().sess,
sym::generic_pattern_types,
self.span,
"wraparound pattern type ranges cause monomorphization time errors",
)
.emit();
}
}
}
};
if let Some(start) = start {
check(start)
}
if let Some(end) = end {
check(end)
}
}
}
}
ty::Tuple(tys) => {

49
tests/ui/type/pattern_types/assoc_const.default.stderr
View file

@ -1,3 +1,24 @@
error[E0658]: wraparound pattern type ranges cause monomorphization time errors
--> $DIR/assoc_const.rs:17:19
|
LL | fn foo<T: Foo>(_: pattern_type!(u32 is <T as Foo>::START..=<T as Foo>::END)) {}
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
|
= note: see issue #136574 <https://github.com/rust-lang/rust/issues/136574> for more information
= help: add `#![feature(generic_pattern_types)]` to the crate attributes to enable
= note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date
error[E0658]: wraparound pattern type ranges cause monomorphization time errors
--> $DIR/assoc_const.rs:17:19
|
LL | fn foo<T: Foo>(_: pattern_type!(u32 is <T as Foo>::START..=<T as Foo>::END)) {}
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
|
= note: see issue #136574 <https://github.com/rust-lang/rust/issues/136574> for more information
= help: add `#![feature(generic_pattern_types)]` to the crate attributes to enable
= note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date
= note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`
error: constant expression depends on a generic parameter
--> $DIR/assoc_const.rs:17:19
|
@ -15,8 +36,29 @@ LL | fn foo<T: Foo>(_: pattern_type!(u32 is <T as Foo>::START..=<T as Foo>::END)
= note: this may fail depending on what value the parameter takes
= note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`
error[E0658]: wraparound pattern type ranges cause monomorphization time errors
--> $DIR/assoc_const.rs:22:19
|
LL | fn bar<T: Foo>(_: pattern_type!(u32 is T::START..=T::END)) {}
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
|
= note: see issue #136574 <https://github.com/rust-lang/rust/issues/136574> for more information
= help: add `#![feature(generic_pattern_types)]` to the crate attributes to enable
= note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date
error[E0658]: wraparound pattern type ranges cause monomorphization time errors
--> $DIR/assoc_const.rs:22:19
|
LL | fn bar<T: Foo>(_: pattern_type!(u32 is T::START..=T::END)) {}
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
|
= note: see issue #136574 <https://github.com/rust-lang/rust/issues/136574> for more information
= help: add `#![feature(generic_pattern_types)]` to the crate attributes to enable
= note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date
= note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`
error: constant expression depends on a generic parameter
--> $DIR/assoc_const.rs:20:19
--> $DIR/assoc_const.rs:22:19
|
LL | fn bar<T: Foo>(_: pattern_type!(u32 is T::START..=T::END)) {}
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@ -24,7 +66,7 @@ LL | fn bar<T: Foo>(_: pattern_type!(u32 is T::START..=T::END)) {}
= note: this may fail depending on what value the parameter takes
error: constant expression depends on a generic parameter
--> $DIR/assoc_const.rs:20:19
--> $DIR/assoc_const.rs:22:19
|
LL | fn bar<T: Foo>(_: pattern_type!(u32 is T::START..=T::END)) {}
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@ -32,5 +74,6 @@ LL | fn bar<T: Foo>(_: pattern_type!(u32 is T::START..=T::END)) {}
= note: this may fail depending on what value the parameter takes
= note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`
error: aborting due to 4 previous errors
error: aborting due to 8 previous errors
For more information about this error, try `rustc --explain E0658`.

8
tests/ui/type/pattern_types/assoc_const.rs
View file

@ -1,8 +1,8 @@
#![feature(pattern_types)]
#![feature(pattern_type_macro)]
#![cfg_attr(const_arg, feature(generic_const_exprs))]
#![cfg_attr(const_arg, feature(generic_const_exprs, generic_pattern_types))]
#![expect(incomplete_features)]
// gate-test-generic_pattern_types line to the test file.
//@ revisions: default const_arg
//@[const_arg] check-pass
@ -17,8 +17,12 @@ trait Foo {
fn foo<T: Foo>(_: pattern_type!(u32 is <T as Foo>::START..=<T as Foo>::END)) {}
//[default]~^ ERROR: constant expression depends on a generic parameter
//[default]~| ERROR: constant expression depends on a generic parameter
//[default]~| ERROR: wraparound pattern type ranges cause monomorphization time errors
//[default]~| ERROR: wraparound pattern type ranges cause monomorphization time errors
fn bar<T: Foo>(_: pattern_type!(u32 is T::START..=T::END)) {}
//[default]~^ ERROR: constant expression depends on a generic parameter
//[default]~| ERROR: constant expression depends on a generic parameter
//[default]~| ERROR: wraparound pattern type ranges cause monomorphization time errors
//[default]~| ERROR: wraparound pattern type ranges cause monomorphization time errors
fn main() {}

4
tests/ui/type/pattern_types/const_generics.rs
View file

@ -1,7 +1,7 @@
//@ check-pass
#![feature(pattern_types)]
#![feature(pattern_type_macro)]
#![feature(pattern_types, generic_pattern_types, pattern_type_macro)]
#![expect(incomplete_features)]
use std::pat::pattern_type;

4
tests/ui/type/pattern_types/transmute.rs
View file

@ -1,5 +1,5 @@
#![feature(pattern_types)]
#![feature(pattern_type_macro)]
#![feature(pattern_types, pattern_type_macro, generic_pattern_types)]
#![expect(incomplete_features)]
use std::pat::pattern_type;