diff --git a/compiler/rustc_trait_selection/src/traits/const_evaluatable.rs b/compiler/rustc_trait_selection/src/traits/const_evaluatable.rs index f8efe9bfa9f82..71fb6058cd2c5 100644 --- a/compiler/rustc_trait_selection/src/traits/const_evaluatable.rs +++ b/compiler/rustc_trait_selection/src/traits/const_evaluatable.rs @@ -168,24 +168,27 @@ fn satisfied_from_param_env<'tcx>( param_env: ty::ParamEnv<'tcx>, infcx: &'a InferCtxt<'tcx>, + single_match: Option, ()>>, } + impl<'a, 'tcx> TypeVisitor<'tcx> for Visitor<'a, 'tcx> { type BreakTy = (); fn visit_const(&mut self, c: ty::Const<'tcx>) -> ControlFlow { debug!("is_const_evaluatable: candidate={:?}", c); - if let Ok(()) = self.infcx.commit_if_ok(|_| { + if self.infcx.probe(|_| { let ocx = ObligationCtxt::new_in_snapshot(self.infcx); - if let Ok(()) = ocx.eq(&ObligationCause::dummy(), self.param_env, c.ty(), self.ct.ty()) - && let Ok(()) = ocx.eq(&ObligationCause::dummy(), self.param_env, c, self.ct) + ocx.eq(&ObligationCause::dummy(), self.param_env, c.ty(), self.ct.ty()).is_ok() + && ocx.eq(&ObligationCause::dummy(), self.param_env, c, self.ct).is_ok() && ocx.select_all_or_error().is_empty() - { - Ok(()) - } else { - Err(()) - } }) { - ControlFlow::BREAK - } else if let ty::ConstKind::Expr(e) = c.kind() { + self.single_match = match self.single_match { + None => Some(Ok(c)), + Some(Ok(o)) if o == c => Some(Ok(c)), + Some(_) => Some(Err(())), + }; + } + + if let ty::ConstKind::Expr(e) = c.kind() { e.visit_with(self) } else { // FIXME(generic_const_exprs): This doesn't recurse into `>::ASSOC`'s substs. @@ -200,22 +203,29 @@ fn satisfied_from_param_env<'tcx>( } } + let mut single_match: Option, ()>> = None; + for pred in param_env.caller_bounds() { match pred.kind().skip_binder() { ty::PredicateKind::ConstEvaluatable(ce) => { let b_ct = tcx.expand_abstract_consts(ce); - let mut v = Visitor { ct, infcx, param_env }; - let result = b_ct.visit_with(&mut v); + let mut v = Visitor { ct, infcx, param_env, single_match }; + let _ = b_ct.visit_with(&mut v); - if let ControlFlow::Break(()) = result { - debug!("is_const_evaluatable: yes"); - return true; - } + single_match = v.single_match; } _ => {} // don't care } } + if let Some(Ok(c)) = single_match { + let ocx = ObligationCtxt::new(infcx); + assert!(ocx.eq(&ObligationCause::dummy(), param_env, c.ty(), ct.ty()).is_ok()); + assert!(ocx.eq(&ObligationCause::dummy(), param_env, c, ct).is_ok()); + assert!(ocx.select_all_or_error().is_empty()); + return true; + } + debug!("is_const_evaluatable: no"); false } diff --git a/src/test/ui/const-generics/ensure_is_evaluatable.rs b/src/test/ui/const-generics/ensure_is_evaluatable.rs new file mode 100644 index 0000000000000..1e8d8c3d3559b --- /dev/null +++ b/src/test/ui/const-generics/ensure_is_evaluatable.rs @@ -0,0 +1,20 @@ +#![feature(generic_const_exprs)] +#![allow(incomplete_features)] + +fn foo() -> [(); N+2] +where + [(); N + 1]:, + [(); M + 1]:, +{ + bar() + //~^ ERROR: unconstrained +} + +fn bar() -> [(); N] +where + [(); N + 1]:, +{ + [(); N] +} + +fn main() {} diff --git a/src/test/ui/const-generics/ensure_is_evaluatable.stderr b/src/test/ui/const-generics/ensure_is_evaluatable.stderr new file mode 100644 index 0000000000000..bf6c35ad8fd86 --- /dev/null +++ b/src/test/ui/const-generics/ensure_is_evaluatable.stderr @@ -0,0 +1,18 @@ +error: unconstrained generic constant + --> $DIR/ensure_is_evaluatable.rs:9:5 + | +LL | bar() + | ^^^ + | + = help: try adding a `where` bound using this expression: `where [(); N + 1]:` +note: required by a bound in `bar` + --> $DIR/ensure_is_evaluatable.rs:15:10 + | +LL | fn bar() -> [(); N] + | --- required by a bound in this +LL | where +LL | [(); N + 1]:, + | ^^^^^ required by this bound in `bar` + +error: aborting due to previous error + diff --git a/src/test/ui/const-generics/fn_with_two_const_inputs.rs b/src/test/ui/const-generics/fn_with_two_const_inputs.rs new file mode 100644 index 0000000000000..0d6246a9f02c3 --- /dev/null +++ b/src/test/ui/const-generics/fn_with_two_const_inputs.rs @@ -0,0 +1,23 @@ +#![feature(generic_const_exprs)] +#![allow(incomplete_features)] + +const fn both(_: usize, b: usize) -> usize { + b +} + +fn foo() -> [(); N + 2] +where + [(); both(N + 1, M + 1)]:, +{ + bar() + //~^ ERROR: unconstrained generic constant +} + +fn bar() -> [(); N] +where + [(); N + 1]:, +{ + [(); N] +} + +fn main() {} diff --git a/src/test/ui/const-generics/fn_with_two_const_inputs.stderr b/src/test/ui/const-generics/fn_with_two_const_inputs.stderr new file mode 100644 index 0000000000000..614e7e0d2fc20 --- /dev/null +++ b/src/test/ui/const-generics/fn_with_two_const_inputs.stderr @@ -0,0 +1,18 @@ +error: unconstrained generic constant + --> $DIR/fn_with_two_const_inputs.rs:12:5 + | +LL | bar() + | ^^^ + | + = help: try adding a `where` bound using this expression: `where [(); N + 1]:` +note: required by a bound in `bar` + --> $DIR/fn_with_two_const_inputs.rs:18:10 + | +LL | fn bar() -> [(); N] + | --- required by a bound in this +LL | where +LL | [(); N + 1]:, + | ^^^^^ required by this bound in `bar` + +error: aborting due to previous error + diff --git a/src/test/ui/const-generics/fn_with_two_same_const_inputs.rs b/src/test/ui/const-generics/fn_with_two_same_const_inputs.rs new file mode 100644 index 0000000000000..f0ce093e07a4f --- /dev/null +++ b/src/test/ui/const-generics/fn_with_two_same_const_inputs.rs @@ -0,0 +1,22 @@ +// check-pass +#![feature(generic_const_exprs)] +#![allow(incomplete_features)] + +const fn both(_: usize, b: usize) -> usize { + b +} + +fn foo() +where + [(); both(N + 1, N + 1)]:, +{ + bar::(); +} + +fn bar() +where + [(); N + 1]:, +{ +} + +fn main() {} diff --git a/src/test/ui/const-generics/issues/issue-105037.rs b/src/test/ui/const-generics/issues/issue-105037.rs new file mode 100644 index 0000000000000..f7d2394994396 --- /dev/null +++ b/src/test/ui/const-generics/issues/issue-105037.rs @@ -0,0 +1,35 @@ +// run-pass +#![feature(generic_const_exprs)] +#![allow(incomplete_features)] +#![allow(dead_code)] + +trait Table: Sync { + const COLUMNS: usize; +} + +struct Table1; +impl Table for Table1 { + const COLUMNS: usize = 123; +} + +struct Table2; +impl Table for Table2 { + const COLUMNS: usize = 456; +} + +fn process_table, const D: usize>(_table: T) +where + [(); T::COLUMNS]:, +{ +} + +fn process_all_tables() +where + [(); Table2::::COLUMNS]:, + [(); Table1::::COLUMNS]:, +{ + process_table(Table1::); + process_table(Table2::); +} + +fn main() {} diff --git a/src/test/ui/const-generics/two_matching_preds.rs b/src/test/ui/const-generics/two_matching_preds.rs new file mode 100644 index 0000000000000..de608f73e2c0c --- /dev/null +++ b/src/test/ui/const-generics/two_matching_preds.rs @@ -0,0 +1,19 @@ +// check-pass +#![feature(generic_const_exprs)] +#![allow(incomplete_features)] + +fn foo() +where + [(); N + 1]:, + [(); N + 1]:, +{ + bar::(); +} + +fn bar() +where + [(); N + 1]:, +{ +} + +fn main() {} diff --git a/src/test/ui/const-generics/unify_with_nested_expr.rs b/src/test/ui/const-generics/unify_with_nested_expr.rs new file mode 100644 index 0000000000000..1271e0902a3bd --- /dev/null +++ b/src/test/ui/const-generics/unify_with_nested_expr.rs @@ -0,0 +1,18 @@ +#![feature(generic_const_exprs)] +#![allow(incomplete_features)] + +fn foo() +where + [(); N + 1 + 1]:, +{ + bar(); + //~^ ERROR: type annotations +} + +fn bar() +where + [(); N + 1]:, +{ +} + +fn main() {} diff --git a/src/test/ui/const-generics/unify_with_nested_expr.stderr b/src/test/ui/const-generics/unify_with_nested_expr.stderr new file mode 100644 index 0000000000000..8bab0dff7f263 --- /dev/null +++ b/src/test/ui/const-generics/unify_with_nested_expr.stderr @@ -0,0 +1,22 @@ +error[E0284]: type annotations needed + --> $DIR/unify_with_nested_expr.rs:8:5 + | +LL | bar(); + | ^^^ cannot infer the value of the const parameter `N` declared on the function `bar` + | +note: required by a bound in `bar` + --> $DIR/unify_with_nested_expr.rs:14:10 + | +LL | fn bar() + | --- required by a bound in this +LL | where +LL | [(); N + 1]:, + | ^^^^^ required by this bound in `bar` +help: consider specifying the generic argument + | +LL | bar::(); + | +++++ + +error: aborting due to previous error + +For more information about this error, try `rustc --explain E0284`.