From c7c3266b8a073ad51e6cc1bc65ff344ad33860a6 Mon Sep 17 00:00:00 2001 From: khyperia <953151+khyperia@users.noreply.github.com> Date: Mon, 2 Feb 2026 20:48:14 +0100 Subject: [PATCH] error on unsized AnonConsts --- compiler/rustc_hir_typeck/src/lib.rs | 8 +++ tests/crashes/137582.rs | 16 ----- .../unsized-anon-const-err-1.rs | 22 +++++++ .../unsized-anon-const-err-1.stderr | 44 +++++++++++++ .../unsized-anon-const-err-2.rs | 21 ++++++ .../unsized-anon-const-err-2.stderr | 66 +++++++++++++++++++ .../unsized-anon-const-func-err.rs | 16 +++++ .../unsized-anon-const-func-err.stderr | 38 +++++++++++ .../unsized-anon-const-struct-err.rs | 16 +++++ .../unsized-anon-const-struct-err.stderr | 38 +++++++++++ 10 files changed, 269 insertions(+), 16 deletions(-) delete mode 100644 tests/crashes/137582.rs create mode 100644 tests/ui/const-generics/adt_const_params/unsized-anon-const-err-1.rs create mode 100644 tests/ui/const-generics/adt_const_params/unsized-anon-const-err-1.stderr create mode 100644 tests/ui/const-generics/adt_const_params/unsized-anon-const-err-2.rs create mode 100644 tests/ui/const-generics/adt_const_params/unsized-anon-const-err-2.stderr create mode 100644 tests/ui/const-generics/adt_const_params/unsized-anon-const-func-err.rs create mode 100644 tests/ui/const-generics/adt_const_params/unsized-anon-const-func-err.stderr create mode 100644 tests/ui/const-generics/adt_const_params/unsized-anon-const-struct-err.rs create mode 100644 tests/ui/const-generics/adt_const_params/unsized-anon-const-struct-err.stderr diff --git a/compiler/rustc_hir_typeck/src/lib.rs b/compiler/rustc_hir_typeck/src/lib.rs index 39c28c4f4e99..6e126b3013c9 100644 --- a/compiler/rustc_hir_typeck/src/lib.rs +++ b/compiler/rustc_hir_typeck/src/lib.rs @@ -200,6 +200,14 @@ fn typeck_with_inspect<'tcx>( let wf_code = ObligationCauseCode::WellFormed(Some(WellFormedLoc::Ty(def_id))); fcx.register_wf_obligation(expected_type.into(), body.value.span, wf_code); + if let hir::Node::AnonConst(_) = node { + fcx.require_type_is_sized( + expected_type, + body.value.span, + ObligationCauseCode::SizedConstOrStatic, + ); + } + fcx.check_expr_coercible_to_type(body.value, expected_type, None); fcx.write_ty(id, expected_type); diff --git a/tests/crashes/137582.rs b/tests/crashes/137582.rs deleted file mode 100644 index e21b6c9578b7..000000000000 --- a/tests/crashes/137582.rs +++ /dev/null @@ -1,16 +0,0 @@ -//@ known-bug: #137582 -#![feature(adt_const_params)] - -mod lib { - pub type Matrix = [&'static u32]; - - const EMPTY_MATRIX: Matrix = [[0; 4]; 4]; - - pub struct Walk { - _p: (), - } - - impl Walk {} -} - -fn main() {} diff --git a/tests/ui/const-generics/adt_const_params/unsized-anon-const-err-1.rs b/tests/ui/const-generics/adt_const_params/unsized-anon-const-err-1.rs new file mode 100644 index 000000000000..17910d52d3d7 --- /dev/null +++ b/tests/ui/const-generics/adt_const_params/unsized-anon-const-err-1.rs @@ -0,0 +1,22 @@ +// regression test for issue #137582, where constant evaluating an unsized AnonConst would ICE + +#![feature(adt_const_params)] + +mod lib { + pub type Matrix = [&'static u32]; + + const EMPTY_MATRIX: Matrix = [[0; 4]; 4]; + //~^ ERROR the size for values of type `[&'static u32]` cannot be known at compilation time + //~| ERROR mismatched types + //~| ERROR mismatched types + + pub struct Walk { + //~^ ERROR use of unstable library feature `unsized_const_params` + _p: (), + } + + impl Walk {} + //~^ ERROR the size for values of type `[&'static u32]` cannot be known at compilation time +} + +fn main() {} diff --git a/tests/ui/const-generics/adt_const_params/unsized-anon-const-err-1.stderr b/tests/ui/const-generics/adt_const_params/unsized-anon-const-err-1.stderr new file mode 100644 index 000000000000..daea55efbbc7 --- /dev/null +++ b/tests/ui/const-generics/adt_const_params/unsized-anon-const-err-1.stderr @@ -0,0 +1,44 @@ +error[E0277]: the size for values of type `[&'static u32]` cannot be known at compilation time + --> $DIR/unsized-anon-const-err-1.rs:8:25 + | +LL | const EMPTY_MATRIX: Matrix = [[0; 4]; 4]; + | ^^^^^^ doesn't have a size known at compile-time + | + = help: the trait `Sized` is not implemented for `[&'static u32]` + = note: statics and constants must have a statically known size + +error[E0658]: use of unstable library feature `unsized_const_params` + --> $DIR/unsized-anon-const-err-1.rs:13:43 + | +LL | pub struct Walk { + | ^^^^^^^^^^^^^^^^^^^^^^^ + | + = help: add `#![feature(unsized_const_params)]` 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: required for `[&'static u32]` to implement `ConstParamTy_` + +error[E0277]: the size for values of type `[&'static u32]` cannot be known at compilation time + --> $DIR/unsized-anon-const-err-1.rs:18:46 + | +LL | impl Walk {} + | ^^^^^^^^^^^^ doesn't have a size known at compile-time + | + = help: the trait `Sized` is not implemented for `[&'static u32]` + = note: statics and constants must have a statically known size + +error[E0308]: mismatched types + --> $DIR/unsized-anon-const-err-1.rs:8:35 + | +LL | const EMPTY_MATRIX: Matrix = [[0; 4]; 4]; + | ^^^^^^ expected `&u32`, found `[{integer}; 4]` + +error[E0308]: mismatched types + --> $DIR/unsized-anon-const-err-1.rs:8:34 + | +LL | const EMPTY_MATRIX: Matrix = [[0; 4]; 4]; + | ^^^^^^^^^^^ expected `[&u32]`, found `[&u32; 4]` + +error: aborting due to 5 previous errors + +Some errors have detailed explanations: E0277, E0308, E0658. +For more information about an error, try `rustc --explain E0277`. diff --git a/tests/ui/const-generics/adt_const_params/unsized-anon-const-err-2.rs b/tests/ui/const-generics/adt_const_params/unsized-anon-const-err-2.rs new file mode 100644 index 000000000000..81b1ec6a7719 --- /dev/null +++ b/tests/ui/const-generics/adt_const_params/unsized-anon-const-err-2.rs @@ -0,0 +1,21 @@ +// regression test for issue #151591, where constant evaluating an unsized AnonConst would ICE + +#![feature(adt_const_params)] +#![feature(unsized_const_params)] +//~^ WARN the feature `unsized_const_params` is incomplete and may not be safe to use and/or cause compiler crashes + +#[derive(Clone)] +struct S; + +const A: [u8]; +//~^ ERROR free constant item without body +//~| ERROR the size for values of type `[u8]` cannot be known at compilation time + +impl Copy for S {} +//~^ ERROR the size for values of type `[u8]` cannot be known at compilation time +//~| ERROR the const parameter `N` is not constrained by the impl trait, self type, or predicates +impl Copy for S {} +//~^ ERROR the size for values of type `[u8]` cannot be known at compilation time +//~| ERROR the const parameter `M` is not constrained by the impl trait, self type, or predicates + +fn main() {} diff --git a/tests/ui/const-generics/adt_const_params/unsized-anon-const-err-2.stderr b/tests/ui/const-generics/adt_const_params/unsized-anon-const-err-2.stderr new file mode 100644 index 000000000000..d538bb0af09a --- /dev/null +++ b/tests/ui/const-generics/adt_const_params/unsized-anon-const-err-2.stderr @@ -0,0 +1,66 @@ +error: free constant item without body + --> $DIR/unsized-anon-const-err-2.rs:10:1 + | +LL | const A: [u8]; + | ^^^^^^^^^^^^^- + | | + | help: provide a definition for the constant: `= ;` + +warning: the feature `unsized_const_params` is incomplete and may not be safe to use and/or cause compiler crashes + --> $DIR/unsized-anon-const-err-2.rs:4:12 + | +LL | #![feature(unsized_const_params)] + | ^^^^^^^^^^^^^^^^^^^^ + | + = note: see issue #95174 for more information + = note: `#[warn(incomplete_features)]` on by default + +error[E0277]: the size for values of type `[u8]` cannot be known at compilation time + --> $DIR/unsized-anon-const-err-2.rs:10:10 + | +LL | const A: [u8]; + | ^^^^ doesn't have a size known at compile-time + | + = help: the trait `Sized` is not implemented for `[u8]` + = note: statics and constants must have a statically known size + +error[E0277]: the size for values of type `[u8]` cannot be known at compilation time + --> $DIR/unsized-anon-const-err-2.rs:14:31 + | +LL | impl Copy for S {} + | ^ doesn't have a size known at compile-time + | + = help: the trait `Sized` is not implemented for `[u8]` + = note: statics and constants must have a statically known size + +error[E0277]: the size for values of type `[u8]` cannot be known at compilation time + --> $DIR/unsized-anon-const-err-2.rs:17:33 + | +LL | impl Copy for S {} + | ^ doesn't have a size known at compile-time + | + = help: the trait `Sized` is not implemented for `[u8]` + = note: statics and constants must have a statically known size + +error[E0207]: the const parameter `N` is not constrained by the impl trait, self type, or predicates + --> $DIR/unsized-anon-const-err-2.rs:14:6 + | +LL | impl Copy for S {} + | ^^^^^^^^^^^^ unconstrained const parameter + | + = note: expressions using a const parameter must map each value to a distinct output value + = note: proving the result of expressions other than the parameter are unique is not supported + +error[E0207]: the const parameter `M` is not constrained by the impl trait, self type, or predicates + --> $DIR/unsized-anon-const-err-2.rs:17:6 + | +LL | impl Copy for S {} + | ^^^^^^^^^^^^^^ unconstrained const parameter + | + = note: expressions using a const parameter must map each value to a distinct output value + = note: proving the result of expressions other than the parameter are unique is not supported + +error: aborting due to 6 previous errors; 1 warning emitted + +Some errors have detailed explanations: E0207, E0277. +For more information about an error, try `rustc --explain E0207`. diff --git a/tests/ui/const-generics/adt_const_params/unsized-anon-const-func-err.rs b/tests/ui/const-generics/adt_const_params/unsized-anon-const-func-err.rs new file mode 100644 index 000000000000..a299cc29fcc5 --- /dev/null +++ b/tests/ui/const-generics/adt_const_params/unsized-anon-const-func-err.rs @@ -0,0 +1,16 @@ +// manually reduced reproduction of issue #137582, where constant evaluating an unsized AnonConst +// would ICE + +#![feature(adt_const_params)] + +fn func() {} +//~^ ERROR use of unstable library feature `unsized_const_params` + +const VALUE: [u32] = [0; 4]; +//~^ ERROR mismatched types +//~| ERROR the size for values of type `[u32]` cannot be known at compilation time + +fn main() { + func::(); + //~^ ERROR the size for values of type `[u32]` cannot be known at compilation time +} diff --git a/tests/ui/const-generics/adt_const_params/unsized-anon-const-func-err.stderr b/tests/ui/const-generics/adt_const_params/unsized-anon-const-func-err.stderr new file mode 100644 index 000000000000..14a41e87e4aa --- /dev/null +++ b/tests/ui/const-generics/adt_const_params/unsized-anon-const-func-err.stderr @@ -0,0 +1,38 @@ +error[E0658]: use of unstable library feature `unsized_const_params` + --> $DIR/unsized-anon-const-func-err.rs:6:9 + | +LL | fn func() {} + | ^^^^^^^^^^^^^^ + | + = help: add `#![feature(unsized_const_params)]` 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: required for `[u32]` to implement `ConstParamTy_` + +error[E0277]: the size for values of type `[u32]` cannot be known at compilation time + --> $DIR/unsized-anon-const-func-err.rs:9:14 + | +LL | const VALUE: [u32] = [0; 4]; + | ^^^^^ doesn't have a size known at compile-time + | + = help: the trait `Sized` is not implemented for `[u32]` + = note: statics and constants must have a statically known size + +error[E0308]: mismatched types + --> $DIR/unsized-anon-const-func-err.rs:9:22 + | +LL | const VALUE: [u32] = [0; 4]; + | ^^^^^^ expected `[u32]`, found `[u32; 4]` + +error[E0277]: the size for values of type `[u32]` cannot be known at compilation time + --> $DIR/unsized-anon-const-func-err.rs:14:12 + | +LL | func::(); + | ^^^^^ doesn't have a size known at compile-time + | + = help: the trait `Sized` is not implemented for `[u32]` + = note: statics and constants must have a statically known size + +error: aborting due to 4 previous errors + +Some errors have detailed explanations: E0277, E0308, E0658. +For more information about an error, try `rustc --explain E0277`. diff --git a/tests/ui/const-generics/adt_const_params/unsized-anon-const-struct-err.rs b/tests/ui/const-generics/adt_const_params/unsized-anon-const-struct-err.rs new file mode 100644 index 000000000000..35407d02f6ef --- /dev/null +++ b/tests/ui/const-generics/adt_const_params/unsized-anon-const-struct-err.rs @@ -0,0 +1,16 @@ +// manually reduced reproduction of issue #137582, where constant evaluating an unsized AnonConst +// would ICE + +#![feature(adt_const_params)] + +const VALUE: [u32] = [0; 4]; +//~^ ERROR the size for values of type `[u32]` cannot be known at compilation time +//~| ERROR mismatched types + +struct SomeStruct {} +//~^ ERROR use of unstable library feature `unsized_const_params` + +impl SomeStruct {} +//~^ ERROR the size for values of type `[u32]` cannot be known at compilation time + +fn main() {} diff --git a/tests/ui/const-generics/adt_const_params/unsized-anon-const-struct-err.stderr b/tests/ui/const-generics/adt_const_params/unsized-anon-const-struct-err.stderr new file mode 100644 index 000000000000..d9a13976d68a --- /dev/null +++ b/tests/ui/const-generics/adt_const_params/unsized-anon-const-struct-err.stderr @@ -0,0 +1,38 @@ +error[E0277]: the size for values of type `[u32]` cannot be known at compilation time + --> $DIR/unsized-anon-const-struct-err.rs:6:14 + | +LL | const VALUE: [u32] = [0; 4]; + | ^^^^^ doesn't have a size known at compile-time + | + = help: the trait `Sized` is not implemented for `[u32]` + = note: statics and constants must have a statically known size + +error[E0658]: use of unstable library feature `unsized_const_params` + --> $DIR/unsized-anon-const-struct-err.rs:10:19 + | +LL | struct SomeStruct {} + | ^^^^^^^^^^^^^^ + | + = help: add `#![feature(unsized_const_params)]` 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: required for `[u32]` to implement `ConstParamTy_` + +error[E0277]: the size for values of type `[u32]` cannot be known at compilation time + --> $DIR/unsized-anon-const-struct-err.rs:13:17 + | +LL | impl SomeStruct {} + | ^^^^^ doesn't have a size known at compile-time + | + = help: the trait `Sized` is not implemented for `[u32]` + = note: statics and constants must have a statically known size + +error[E0308]: mismatched types + --> $DIR/unsized-anon-const-struct-err.rs:6:22 + | +LL | const VALUE: [u32] = [0; 4]; + | ^^^^^^ expected `[u32]`, found `[u32; 4]` + +error: aborting due to 4 previous errors + +Some errors have detailed explanations: E0277, E0308, E0658. +For more information about an error, try `rustc --explain E0277`.