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Auto merge of #149389 - ShoyuVanilla:local-region-param-wf, r=lcnr

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WF check lifetime bounds for locals with type params

FCP proposal in https://github.com/rust-lang/rust/pull/149389#issuecomment-3669689488

Fixes rust-lang/rust#115175
Fixes rust-lang/rust#148854
This commit is contained in:
bors 2026-02-14 02:52:05 +00:00
commit 29fa07e3db
22 changed files with 123 additions and 26 deletions
Download patch file Download diff file Expand all files Collapse all files

3
compiler/rustc_hir_typeck/src/fn_ctxt/_impl.rs
View file

@ -581,7 +581,8 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
where
T: TypeVisitable<TyCtxt<'tcx>>,
{
t.has_free_regions() || t.has_aliases() || t.has_infer_types()
// FIXME(mgca): should this also count stuff with infer consts
t.has_free_regions() || t.has_aliases() || t.has_infer_types() || t.has_param()
}
pub(crate) fn node_ty(&self, id: HirId) -> Ty<'tcx> {

3
src/ci/docker/scripts/rfl-build.sh
View file

@ -3,7 +3,8 @@
set -euo pipefail
# https://github.com/rust-lang/rust/pull/151534
LINUX_VERSION=eb268c7972f65fa0b11b051c5ef2b92747bb2b62
# https://github.com/rust-lang/rust/pull/149389
LINUX_VERSION=167ea5357eb7c3a39200627a36dfbfe249576192
# Build rustc, rustdoc, cargo, clippy-driver and rustfmt
../x.py build --stage 2 library rustdoc clippy rustfmt

2
tests/mir-opt/inline_coroutine_body.run2-{closure#0}.Inline.panic-abort.diff
View file

@ -197,8 +197,8 @@
+ StorageLive(_40);
+ _40 = &raw mut _19;
+ _39 = copy _40 as *mut std::pin::helper::PinHelper<&mut std::future::Ready<()>> (PtrToPtr);
+ StorageDead(_40);
+ _37 = copy ((*_39).0: &mut std::future::Ready<()>);
+ StorageDead(_40);
+ StorageLive(_42);
+ _42 = Option::<()>::None;
+ _35 = copy ((*_37).0: std::option::Option<()>);

2
tests/mir-opt/inline_coroutine_body.run2-{closure#0}.Inline.panic-unwind.diff
View file

@ -208,8 +208,8 @@
+ StorageLive(_40);
+ _40 = &raw mut _19;
+ _39 = copy _40 as *mut std::pin::helper::PinHelper<&mut std::future::Ready<()>> (PtrToPtr);
+ StorageDead(_40);
+ _37 = copy ((*_39).0: &mut std::future::Ready<()>);
+ StorageDead(_40);
+ StorageLive(_42);
+ _42 = Option::<()>::None;
+ _35 = copy ((*_37).0: std::option::Option<()>);

10
tests/mir-opt/instsimplify/casts.redundant.InstSimplify-after-simplifycfg.diff
View file

@ -9,6 +9,7 @@
let mut _4: *const &u8;
scope 1 (inlined generic_cast::<&u8, &u8>) {
let mut _5: *const &u8;
let mut _6: *const &u8;
}
bb0: {
@ -17,9 +18,12 @@
StorageLive(_4);
_4 = copy _1;
StorageLive(_5);
_5 = copy _4;
- _3 = move _5 as *const &u8 (PtrToPtr);
+ _3 = move _5;
StorageLive(_6);
_6 = copy _4;
- _5 = move _6 as *const &u8 (PtrToPtr);
+ _5 = move _6;
_3 = copy _5;
StorageDead(_6);
StorageDead(_5);
StorageDead(_4);
- _2 = move _3 as *const &u8 (PtrToPtr);

2
tests/mir-opt/pre-codegen/slice_index.slice_get_unchecked_mut_range.PreCodegen.after.panic-abort.mir
View file

@ -15,7 +15,7 @@ fn slice_get_unchecked_mut_range(_1: &mut [u32], _2: std::ops::Range<usize>) ->
let _8: usize;
scope 3 {
scope 6 (inlined core::slice::index::get_offset_len_mut_noubcheck::<u32>) {
let _9: *mut u32;
let mut _9: *mut u32;
scope 7 {
let _10: *mut u32;
scope 8 {

2
tests/mir-opt/pre-codegen/slice_index.slice_get_unchecked_mut_range.PreCodegen.after.panic-unwind.mir
View file

@ -15,7 +15,7 @@ fn slice_get_unchecked_mut_range(_1: &mut [u32], _2: std::ops::Range<usize>) ->
let _8: usize;
scope 3 {
scope 6 (inlined core::slice::index::get_offset_len_mut_noubcheck::<u32>) {
let _9: *mut u32;
let mut _9: *mut u32;
scope 7 {
let _10: *mut u32;
scope 8 {

2
tests/mir-opt/pre-codegen/slice_index.slice_index_range.PreCodegen.after.panic-abort.mir
View file

@ -19,7 +19,7 @@ fn slice_index_range(_1: &[u32], _2: std::ops::Range<usize>) -> &[u32] {
let mut _6: usize;
}
scope 4 (inlined core::slice::index::get_offset_len_noubcheck::<u32>) {
let _10: *const u32;
let mut _10: *const u32;
scope 5 {
let _11: *const u32;
scope 6 {

2
tests/mir-opt/pre-codegen/slice_index.slice_index_range.PreCodegen.after.panic-unwind.mir
View file

@ -19,7 +19,7 @@ fn slice_index_range(_1: &[u32], _2: std::ops::Range<usize>) -> &[u32] {
let mut _6: usize;
}
scope 4 (inlined core::slice::index::get_offset_len_noubcheck::<u32>) {
let _10: *const u32;
let mut _10: *const u32;
scope 5 {
let _11: *const u32;
scope 6 {

2
tests/mir-opt/pre-codegen/slice_index.slice_ptr_get_unchecked_range.PreCodegen.after.panic-abort.mir
View file

@ -13,7 +13,7 @@ fn slice_ptr_get_unchecked_range(_1: *const [u32], _2: std::ops::Range<usize>) -
let _7: usize;
scope 3 {
scope 6 (inlined core::slice::index::get_offset_len_noubcheck::<u32>) {
let _8: *const u32;
let mut _8: *const u32;
scope 7 {
let _9: *const u32;
scope 8 {

2
tests/mir-opt/pre-codegen/slice_index.slice_ptr_get_unchecked_range.PreCodegen.after.panic-unwind.mir
View file

@ -13,7 +13,7 @@ fn slice_ptr_get_unchecked_range(_1: *const [u32], _2: std::ops::Range<usize>) -
let _7: usize;
scope 3 {
scope 6 (inlined core::slice::index::get_offset_len_noubcheck::<u32>) {
let _8: *const u32;
let mut _8: *const u32;
scope 7 {
let _9: *const u32;
scope 8 {

4
tests/ui/consts/issue-102117.stderr
View file

@ -2,7 +2,7 @@ error[E0310]: the parameter type `T` may not live long enough
--> $DIR/issue-102117.rs:17:26
|
LL | type_id: TypeId::of::<T>(),
| ^^^^^^^^^^^^^^^^^
| ^^^^^^^^^^^^^^^
| |
| the parameter type `T` must be valid for the static lifetime...
| ...so that the type `T` will meet its required lifetime bounds
@ -16,7 +16,7 @@ error[E0310]: the parameter type `T` may not live long enough
--> $DIR/issue-102117.rs:17:26
|
LL | type_id: TypeId::of::<T>(),
| ^^^^^^^^^^^^^^^^^
| ^^^^^^^^^^^^^^^
| |
| the parameter type `T` must be valid for the static lifetime...
| ...so that the type `T` will meet its required lifetime bounds

7
tests/ui/higher-ranked/leak-check/candidate-from-env-universe-err-project.current.stderr
View file

@ -2,15 +2,10 @@ error[E0308]: mismatched types
--> $DIR/candidate-from-env-universe-err-project.rs:38:5
|
LL | projection_bound::<T>();
| ^^^^^^^^^^^^^^^^^^^^^^^ one type is more general than the other
| ^^^^^^^^^^^^^^^^^^^^^ one type is more general than the other
|
= note: expected associated type `<T as Trait<'static>>::Assoc`
found associated type `<T as Trait<'a>>::Assoc`
note: the lifetime requirement is introduced here
--> $DIR/candidate-from-env-universe-err-project.rs:19:42
|
LL | fn projection_bound<T: for<'a> Trait<'a, Assoc = usize>>() {}
| ^^^^^^^^^^^^^
error[E0308]: mismatched types
--> $DIR/candidate-from-env-universe-err-project.rs:52:30

2
tests/ui/nll/issue-98693.stderr
View file

@ -2,7 +2,7 @@ error[E0310]: the parameter type `T` may not live long enough
--> $DIR/issue-98693.rs:16:9
|
LL | assert_static::<T>();
| ^^^^^^^^^^^^^^^^^^^^
| ^^^^^^^^^^^^^^^^^^
| |
| the parameter type `T` must be valid for the static lifetime...
| ...so that the type `T` will meet its required lifetime bounds

2
tests/ui/nll/type-test-universe.stderr
View file

@ -2,7 +2,7 @@ error: `S` does not live long enough
--> $DIR/type-test-universe.rs:11:5
|
LL | outlives_forall::<S>();
| ^^^^^^^^^^^^^^^^^^^^^^
| ^^^^^^^^^^^^^^^^^^^^
error: lifetime may not live long enough
--> $DIR/type-test-universe.rs:17:5

2
tests/ui/regions/forall-wf-ref-reflexive.stderr
View file

@ -2,7 +2,7 @@ error: `T` does not live long enough
--> $DIR/forall-wf-ref-reflexive.rs:12:5
|
LL | self_wf2::<T>();
| ^^^^^^^^^^^^^^^
| ^^^^^^^^^^^^^
error: aborting due to 1 previous error

11
tests/ui/regions/wf-bound-region-in-local-issue-115175.rs Normal file
View file

@ -0,0 +1,11 @@
// A regression test for https://github.com/rust-lang/rust/issues/115175.
// This used to compile without error despite of unsatisfied outlives bound `T: 'static` on local.
struct Static<T: 'static>(T);
fn test<T>() {
let _ = None::<Static<T>>;
//~^ ERROR the parameter type `T` may not live long enough
}
fn main() {}

17
tests/ui/regions/wf-bound-region-in-local-issue-115175.stderr Normal file
View file

@ -0,0 +1,17 @@
error[E0310]: the parameter type `T` may not live long enough
--> $DIR/wf-bound-region-in-local-issue-115175.rs:7:13
|
LL | let _ = None::<Static<T>>;
| ^^^^^^^^^^^^^^^^^
| |
| the parameter type `T` must be valid for the static lifetime...
| ...so that the type `T` will meet its required lifetime bounds
|
help: consider adding an explicit lifetime bound
|
LL | fn test<T: 'static>() {
| +++++++++
error: aborting due to 1 previous error
For more information about this error, try `rustc --explain E0310`.

51
tests/ui/regions/wf-bound-region-in-local-soundness-issue-148854.rs Normal file
View file

@ -0,0 +1,51 @@
// A regression test for https://github.com/rust-lang/rust/issues/148854.
use std::cell::OnceCell;
use std::fmt::Display;
use std::marker::PhantomData;
use std::rc::Rc;
type Storage = Rc<OnceCell<Box<dyn Display + 'static>>>;
trait IntoDyn<T> {
fn into_dyn(input: T, output: Storage);
}
struct Inner<T: Display + 'static>(PhantomData<T>);
impl<T: Display> IntoDyn<T> for Inner<T> {
fn into_dyn(input: T, output: Storage) {
output.set(Box::new(input)).ok().unwrap();
}
}
struct Outer<T, U: IntoDyn<T>> {
input: Option<T>,
output: Storage,
_phantom: PhantomData<U>,
}
impl<T, U: IntoDyn<T>> Drop for Outer<T, U> {
fn drop(&mut self) {
U::into_dyn(self.input.take().unwrap(), self.output.clone());
}
}
fn extend<T: Display>(x: T) -> Box<dyn Display + 'static> {
let storage = Rc::new(OnceCell::new());
{
// This has to error due to an unsatisfied outlives bound on
// `Inner<T: 'static>` as its implicit drop relies on that
// bound.
let _ =
Outer::<T, Inner<T>> { input: Some(x), output: storage.clone(), _phantom: PhantomData };
//~^ ERROR: the parameter type `T` may not live long enough
}
Rc::into_inner(storage).unwrap().into_inner().unwrap()
}
fn main() {
let wrong = {
let data = String::from("abc");
extend::<&String>(&data)
};
println!("{wrong}");
}

17
tests/ui/regions/wf-bound-region-in-local-soundness-issue-148854.stderr Normal file
View file

@ -0,0 +1,17 @@
error[E0310]: the parameter type `T` may not live long enough
--> $DIR/wf-bound-region-in-local-soundness-issue-148854.rs:39:13
|
LL | Outer::<T, Inner<T>> { input: Some(x), output: storage.clone(), _phantom: PhantomData };
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
| |
| the parameter type `T` must be valid for the static lifetime...
| ...so that the type `T` will meet its required lifetime bounds
|
help: consider adding an explicit lifetime bound
|
LL | fn extend<T: Display + 'static>(x: T) -> Box<dyn Display + 'static> {
| +++++++++
error: aborting due to 1 previous error
For more information about this error, try `rustc --explain E0310`.

2
tests/ui/type-alias-impl-trait/implied_lifetime_wf_check3.stderr
View file

@ -28,7 +28,7 @@ error[E0310]: the parameter type `A` may not live long enough
--> $DIR/implied_lifetime_wf_check3.rs:55:5
|
LL | test_type_param::assert_static::<A>()
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
| |
| the parameter type `A` must be valid for the static lifetime...
| ...so that the type `A` will meet its required lifetime bounds

2
tests/ui/type-alias-impl-trait/implied_lifetime_wf_check4_static.stderr
View file

@ -21,7 +21,7 @@ error[E0310]: the parameter type `A` may not live long enough
--> $DIR/implied_lifetime_wf_check4_static.rs:15:5
|
LL | assert_static::<A>()
| ^^^^^^^^^^^^^^^^^^^^
| ^^^^^^^^^^^^^^^^^^
| |
| the parameter type `A` must be valid for the static lifetime...
| ...so that the type `A` will meet its required lifetime bounds