From 24acf8602969215469ac26a2c0042385096345d9 Mon Sep 17 00:00:00 2001 From: Nilstrieb <48135649+Nilstrieb@users.noreply.github.com> Date: Sat, 13 Nov 2021 23:56:22 +0100 Subject: [PATCH] Fix span for non-satisfied trivial trait bounds The spans for "trait bound not satisfied" errors in trivial trait bounds referenced the entire item (fn, impl, struct) before. Now they only reference the obligation itself (`String: Copy`) Address #90869 --- compiler/rustc_infer/src/traits/util.rs | 17 +++++ .../rustc_trait_selection/src/traits/mod.rs | 3 +- compiler/rustc_typeck/src/check/wfcheck.rs | 25 +++++- .../ui/const-generics/issues/issue-67185-2.rs | 9 +-- .../issues/issue-67185-2.stderr | 60 ++++++--------- src/test/ui/cross/cross-fn-cache-hole.rs | 4 +- src/test/ui/cross/cross-fn-cache-hole.stderr | 12 +-- .../feature-gate-trivial_bounds.stderr | 76 +++++++------------ 8 files changed, 102 insertions(+), 104 deletions(-) diff --git a/compiler/rustc_infer/src/traits/util.rs b/compiler/rustc_infer/src/traits/util.rs index c839f824d1c9c..92f74af4eb3eb 100644 --- a/compiler/rustc_infer/src/traits/util.rs +++ b/compiler/rustc_infer/src/traits/util.rs @@ -5,6 +5,7 @@ use crate::traits::{Obligation, ObligationCause, PredicateObligation}; use rustc_data_structures::fx::{FxHashSet, FxIndexSet}; use rustc_middle::ty::{self, ToPredicate, TyCtxt, WithConstness}; use rustc_span::symbol::Ident; +use rustc_span::Span; pub fn anonymize_predicate<'tcx>( tcx: TyCtxt<'tcx>, @@ -97,6 +98,22 @@ pub fn elaborate_predicates<'tcx>( elaborate_obligations(tcx, obligations) } +pub fn elaborate_predicates_with_span<'tcx>( + tcx: TyCtxt<'tcx>, + predicates: impl Iterator, Span)>, +) -> Elaborator<'tcx> { + let obligations = predicates + .map(|(predicate, span)| { + predicate_obligation( + predicate, + ty::ParamEnv::empty(), + ObligationCause::dummy_with_span(span), + ) + }) + .collect(); + elaborate_obligations(tcx, obligations) +} + pub fn elaborate_obligations<'tcx>( tcx: TyCtxt<'tcx>, mut obligations: Vec>, diff --git a/compiler/rustc_trait_selection/src/traits/mod.rs b/compiler/rustc_trait_selection/src/traits/mod.rs index d4a586b0124a2..91671994c5ace 100644 --- a/compiler/rustc_trait_selection/src/traits/mod.rs +++ b/compiler/rustc_trait_selection/src/traits/mod.rs @@ -65,7 +65,8 @@ pub use self::specialize::{specialization_graph, translate_substs, OverlapError} pub use self::structural_match::search_for_structural_match_violation; pub use self::structural_match::NonStructuralMatchTy; pub use self::util::{ - elaborate_obligations, elaborate_predicates, elaborate_trait_ref, elaborate_trait_refs, + elaborate_obligations, elaborate_predicates, elaborate_predicates_with_span, + elaborate_trait_ref, elaborate_trait_refs, }; pub use self::util::{expand_trait_aliases, TraitAliasExpander}; pub use self::util::{ diff --git a/compiler/rustc_typeck/src/check/wfcheck.rs b/compiler/rustc_typeck/src/check/wfcheck.rs index c1adc2894ccfc..0050ac99cb19a 100644 --- a/compiler/rustc_typeck/src/check/wfcheck.rs +++ b/compiler/rustc_typeck/src/check/wfcheck.rs @@ -1641,19 +1641,38 @@ fn report_bivariance(tcx: TyCtxt<'_>, param: &rustc_hir::GenericParam<'_>) { /// Feature gates RFC 2056 -- trivial bounds, checking for global bounds that /// aren't true. -fn check_false_global_bounds(fcx: &FnCtxt<'_, '_>, span: Span, id: hir::HirId) { +fn check_false_global_bounds(fcx: &FnCtxt<'_, '_>, mut span: Span, id: hir::HirId) { let empty_env = ty::ParamEnv::empty(); let def_id = fcx.tcx.hir().local_def_id(id); - let predicates = fcx.tcx.predicates_of(def_id).predicates.iter().map(|(p, _)| *p); + let predicates_with_span = + fcx.tcx.predicates_of(def_id).predicates.iter().map(|(p, span)| (*p, *span)); // Check elaborated bounds. - let implied_obligations = traits::elaborate_predicates(fcx.tcx, predicates); + let implied_obligations = traits::elaborate_predicates_with_span(fcx.tcx, predicates_with_span); for obligation in implied_obligations { let pred = obligation.predicate; // Match the existing behavior. if pred.is_global(fcx.tcx) && !pred.has_late_bound_regions() { let pred = fcx.normalize_associated_types_in(span, pred); + let hir_node = fcx.tcx.hir().find(id); + + // only use the span of the predicate clause (#90869) + + if let Some(hir::Generics { where_clause, .. }) = + hir_node.and_then(|node| node.generics()) + { + let obligation_span = obligation.cause.span(fcx.tcx); + + span = where_clause + .predicates + .iter() + // There seems to be no better way to find out which predicate we are in + .find(|pred| pred.span().contains(obligation_span)) + .map(|pred| pred.span()) + .unwrap_or(obligation_span); + } + let obligation = traits::Obligation::new( traits::ObligationCause::new(span, id, traits::TrivialBound), empty_env, diff --git a/src/test/ui/const-generics/issues/issue-67185-2.rs b/src/test/ui/const-generics/issues/issue-67185-2.rs index c1a04e2014749..18bb6f6bc1edc 100644 --- a/src/test/ui/const-generics/issues/issue-67185-2.rs +++ b/src/test/ui/const-generics/issues/issue-67185-2.rs @@ -9,11 +9,10 @@ trait Bar {} impl Bar for [u16; 4] {} impl Bar for [[u16; 3]; 3] {} -trait Foo //~ ERROR the trait bound `[u16; 3]: Bar` is not satisfied [E0277] - //~^ ERROR the trait bound `[[u16; 3]; 2]: Bar` is not satisfied [E0277] - where - [::Quaks; 2]: Bar, - ::Quaks: Bar, +trait Foo +where + [::Quaks; 2]: Bar, //~ ERROR the trait bound `[[u16; 3]; 2]: Bar` is not satisfied [E0277] + ::Quaks: Bar, //~ ERROR the trait bound `[u16; 3]: Bar` is not satisfied [E0277] { } diff --git a/src/test/ui/const-generics/issues/issue-67185-2.stderr b/src/test/ui/const-generics/issues/issue-67185-2.stderr index 7167bea94bbb6..89aa3d395e25b 100644 --- a/src/test/ui/const-generics/issues/issue-67185-2.stderr +++ b/src/test/ui/const-generics/issues/issue-67185-2.stderr @@ -1,14 +1,8 @@ error[E0277]: the trait bound `[u16; 3]: Bar` is not satisfied - --> $DIR/issue-67185-2.rs:12:1 + --> $DIR/issue-67185-2.rs:15:5 | -LL | / trait Foo -LL | | -LL | | where -LL | | [::Quaks; 2]: Bar, -LL | | ::Quaks: Bar, -LL | | { -LL | | } - | |_^ the trait `Bar` is not implemented for `[u16; 3]` +LL | ::Quaks: Bar, + | ^^^^^^^^^^^^^^^^^^^^^^^ the trait `Bar` is not implemented for `[u16; 3]` | = help: the following implementations were found: <[[u16; 3]; 3] as Bar> @@ -17,16 +11,10 @@ LL | | } = help: add `#![feature(trivial_bounds)]` to the crate attributes to enable error[E0277]: the trait bound `[[u16; 3]; 2]: Bar` is not satisfied - --> $DIR/issue-67185-2.rs:12:1 + --> $DIR/issue-67185-2.rs:14:5 | -LL | / trait Foo -LL | | -LL | | where -LL | | [::Quaks; 2]: Bar, -LL | | ::Quaks: Bar, -LL | | { -LL | | } - | |_^ the trait `Bar` is not implemented for `[[u16; 3]; 2]` +LL | [::Quaks; 2]: Bar, + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the trait `Bar` is not implemented for `[[u16; 3]; 2]` | = help: the following implementations were found: <[[u16; 3]; 3] as Bar> @@ -35,7 +23,7 @@ LL | | } = help: add `#![feature(trivial_bounds)]` to the crate attributes to enable error[E0277]: the trait bound `[u16; 3]: Bar` is not satisfied - --> $DIR/issue-67185-2.rs:22:6 + --> $DIR/issue-67185-2.rs:21:6 | LL | impl Foo for FooImpl {} | ^^^ the trait `Bar` is not implemented for `[u16; 3]` @@ -44,16 +32,16 @@ LL | impl Foo for FooImpl {} <[[u16; 3]; 3] as Bar> <[u16; 4] as Bar> note: required by a bound in `Foo` - --> $DIR/issue-67185-2.rs:16:29 + --> $DIR/issue-67185-2.rs:15:25 | LL | trait Foo | --- required by a bound in this ... -LL | ::Quaks: Bar, - | ^^^ required by this bound in `Foo` +LL | ::Quaks: Bar, + | ^^^ required by this bound in `Foo` error[E0277]: the trait bound `[[u16; 3]; 2]: Bar` is not satisfied - --> $DIR/issue-67185-2.rs:22:6 + --> $DIR/issue-67185-2.rs:21:6 | LL | impl Foo for FooImpl {} | ^^^ the trait `Bar` is not implemented for `[[u16; 3]; 2]` @@ -62,16 +50,16 @@ LL | impl Foo for FooImpl {} <[[u16; 3]; 3] as Bar> <[u16; 4] as Bar> note: required by a bound in `Foo` - --> $DIR/issue-67185-2.rs:15:34 + --> $DIR/issue-67185-2.rs:14:30 | LL | trait Foo | --- required by a bound in this -... -LL | [::Quaks; 2]: Bar, - | ^^^ required by this bound in `Foo` +LL | where +LL | [::Quaks; 2]: Bar, + | ^^^ required by this bound in `Foo` error[E0277]: the trait bound `[[u16; 3]; 2]: Bar` is not satisfied - --> $DIR/issue-67185-2.rs:26:14 + --> $DIR/issue-67185-2.rs:25:14 | LL | fn f(_: impl Foo) {} | ^^^ the trait `Bar` is not implemented for `[[u16; 3]; 2]` @@ -80,16 +68,16 @@ LL | fn f(_: impl Foo) {} <[[u16; 3]; 3] as Bar> <[u16; 4] as Bar> note: required by a bound in `Foo` - --> $DIR/issue-67185-2.rs:15:34 + --> $DIR/issue-67185-2.rs:14:30 | LL | trait Foo | --- required by a bound in this -... -LL | [::Quaks; 2]: Bar, - | ^^^ required by this bound in `Foo` +LL | where +LL | [::Quaks; 2]: Bar, + | ^^^ required by this bound in `Foo` error[E0277]: the trait bound `[u16; 3]: Bar` is not satisfied - --> $DIR/issue-67185-2.rs:26:14 + --> $DIR/issue-67185-2.rs:25:14 | LL | fn f(_: impl Foo) {} | ^^^ the trait `Bar` is not implemented for `[u16; 3]` @@ -98,13 +86,13 @@ LL | fn f(_: impl Foo) {} <[[u16; 3]; 3] as Bar> <[u16; 4] as Bar> note: required by a bound in `Foo` - --> $DIR/issue-67185-2.rs:16:29 + --> $DIR/issue-67185-2.rs:15:25 | LL | trait Foo | --- required by a bound in this ... -LL | ::Quaks: Bar, - | ^^^ required by this bound in `Foo` +LL | ::Quaks: Bar, + | ^^^ required by this bound in `Foo` error: aborting due to 6 previous errors diff --git a/src/test/ui/cross/cross-fn-cache-hole.rs b/src/test/ui/cross/cross-fn-cache-hole.rs index 249c6474c9420..c38a5001ac86d 100644 --- a/src/test/ui/cross/cross-fn-cache-hole.rs +++ b/src/test/ui/cross/cross-fn-cache-hole.rs @@ -12,8 +12,8 @@ trait Bar { } // We don't always check where clauses for sanity, but in this case // wfcheck does report an error here: -fn vacuous() //~ ERROR the trait bound `i32: Bar` is not satisfied - where i32: Foo +fn vacuous() + where i32: Foo //~ ERROR the trait bound `i32: Bar` is not satisfied { // ... the original intention was to check that we don't use that // vacuous where clause (which could never be satisfied) to accept diff --git a/src/test/ui/cross/cross-fn-cache-hole.stderr b/src/test/ui/cross/cross-fn-cache-hole.stderr index 0d325bb7ec102..7e15562b0816b 100644 --- a/src/test/ui/cross/cross-fn-cache-hole.stderr +++ b/src/test/ui/cross/cross-fn-cache-hole.stderr @@ -1,14 +1,8 @@ error[E0277]: the trait bound `i32: Bar` is not satisfied - --> $DIR/cross-fn-cache-hole.rs:15:1 + --> $DIR/cross-fn-cache-hole.rs:16:11 | -LL | / fn vacuous() -LL | | where i32: Foo -LL | | { -LL | | // ... the original intention was to check that we don't use that -... | -LL | | require::(); -LL | | } - | |_^ the trait `Bar` is not implemented for `i32` +LL | where i32: Foo + | ^^^^^^^^^^^^^^^^ the trait `Bar` is not implemented for `i32` | = help: see issue #48214 = help: add `#![feature(trivial_bounds)]` to the crate attributes to enable diff --git a/src/test/ui/feature-gates/feature-gate-trivial_bounds.stderr b/src/test/ui/feature-gates/feature-gate-trivial_bounds.stderr index 78904b383f49a..28c49c33bf6b5 100644 --- a/src/test/ui/feature-gates/feature-gate-trivial_bounds.stderr +++ b/src/test/ui/feature-gates/feature-gate-trivial_bounds.stderr @@ -1,87 +1,71 @@ error[E0277]: the trait bound `i32: Foo` is not satisfied - --> $DIR/feature-gate-trivial_bounds.rs:10:1 + --> $DIR/feature-gate-trivial_bounds.rs:10:14 | LL | enum E where i32: Foo { V } - | ^^^^^^^^^^^^^^^^^^^^^^^^^^^ the trait `Foo` is not implemented for `i32` + | ^^^^^^^^ the trait `Foo` is not implemented for `i32` | = help: see issue #48214 = help: add `#![feature(trivial_bounds)]` to the crate attributes to enable error[E0277]: the trait bound `i32: Foo` is not satisfied - --> $DIR/feature-gate-trivial_bounds.rs:12:1 + --> $DIR/feature-gate-trivial_bounds.rs:12:16 | LL | struct S where i32: Foo; - | ^^^^^^^^^^^^^^^^^^^^^^^^ the trait `Foo` is not implemented for `i32` + | ^^^^^^^^ the trait `Foo` is not implemented for `i32` | = help: see issue #48214 = help: add `#![feature(trivial_bounds)]` to the crate attributes to enable error[E0277]: the trait bound `i32: Foo` is not satisfied - --> $DIR/feature-gate-trivial_bounds.rs:14:1 + --> $DIR/feature-gate-trivial_bounds.rs:14:15 | LL | trait T where i32: Foo {} - | ^^^^^^^^^^^^^^^^^^^^^^^^^ the trait `Foo` is not implemented for `i32` + | ^^^^^^^^ the trait `Foo` is not implemented for `i32` | = help: see issue #48214 = help: add `#![feature(trivial_bounds)]` to the crate attributes to enable error[E0277]: the trait bound `i32: Foo` is not satisfied - --> $DIR/feature-gate-trivial_bounds.rs:16:1 + --> $DIR/feature-gate-trivial_bounds.rs:16:15 | LL | union U where i32: Foo { f: i32 } - | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the trait `Foo` is not implemented for `i32` + | ^^^^^^^^ the trait `Foo` is not implemented for `i32` | = help: see issue #48214 = help: add `#![feature(trivial_bounds)]` to the crate attributes to enable error[E0277]: the trait bound `i32: Foo` is not satisfied - --> $DIR/feature-gate-trivial_bounds.rs:20:1 + --> $DIR/feature-gate-trivial_bounds.rs:20:23 | -LL | / impl Foo for () where i32: Foo { -LL | | fn test(&self) { -LL | | 3i32.test(); -LL | | Foo::test(&4i32); -LL | | generic_function(5i32); -LL | | } -LL | | } - | |_^ the trait `Foo` is not implemented for `i32` +LL | impl Foo for () where i32: Foo { + | ^^^^^^^^ the trait `Foo` is not implemented for `i32` | = help: see issue #48214 = help: add `#![feature(trivial_bounds)]` to the crate attributes to enable error[E0277]: the trait bound `i32: Foo` is not satisfied - --> $DIR/feature-gate-trivial_bounds.rs:28:1 + --> $DIR/feature-gate-trivial_bounds.rs:28:14 | -LL | / fn f() where i32: Foo -LL | | { -LL | | let s = S; -LL | | 3i32.test(); -LL | | Foo::test(&4i32); -LL | | generic_function(5i32); -LL | | } - | |_^ the trait `Foo` is not implemented for `i32` +LL | fn f() where i32: Foo + | ^^^^^^^^ the trait `Foo` is not implemented for `i32` | = help: see issue #48214 = help: add `#![feature(trivial_bounds)]` to the crate attributes to enable error[E0277]: the trait bound `String: Neg` is not satisfied - --> $DIR/feature-gate-trivial_bounds.rs:36:1 + --> $DIR/feature-gate-trivial_bounds.rs:36:38 | -LL | / fn use_op(s: String) -> String where String: ::std::ops::Neg { -LL | | -s -LL | | } - | |_^ the trait `Neg` is not implemented for `String` +LL | fn use_op(s: String) -> String where String: ::std::ops::Neg { + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the trait `Neg` is not implemented for `String` | = help: see issue #48214 = help: add `#![feature(trivial_bounds)]` to the crate attributes to enable error[E0277]: `i32` is not an iterator - --> $DIR/feature-gate-trivial_bounds.rs:40:1 + --> $DIR/feature-gate-trivial_bounds.rs:40:20 | -LL | / fn use_for() where i32: Iterator { -LL | | for _ in 2i32 {} -LL | | } - | |_^ `i32` is not an iterator +LL | fn use_for() where i32: Iterator { + | ^^^^^^^^^^^^^ `i32` is not an iterator | = help: the trait `Iterator` is not implemented for `i32` = note: if you want to iterate between `start` until a value `end`, use the exclusive range syntax `start..end` or the inclusive range syntax `start..=end` @@ -89,22 +73,20 @@ LL | | } = help: add `#![feature(trivial_bounds)]` to the crate attributes to enable error[E0277]: the size for values of type `str` cannot be known at compilation time - --> $DIR/feature-gate-trivial_bounds.rs:52:1 + --> $DIR/feature-gate-trivial_bounds.rs:52:32 | LL | struct TwoStrs(str, str) where str: Sized; - | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ doesn't have a size known at compile-time + | ^^^^^^^^^^ doesn't have a size known at compile-time | = help: the trait `Sized` is not implemented for `str` = help: see issue #48214 = help: add `#![feature(trivial_bounds)]` to the crate attributes to enable error[E0277]: the size for values of type `(dyn A + 'static)` cannot be known at compilation time - --> $DIR/feature-gate-trivial_bounds.rs:55:1 + --> $DIR/feature-gate-trivial_bounds.rs:55:26 | -LL | / fn unsized_local() where Dst: Sized { -LL | | let x: Dst = *(Box::new(Dst { x: 1 }) as Box>); -LL | | } - | |_^ doesn't have a size known at compile-time +LL | fn unsized_local() where Dst: Sized { + | ^^^^^^^^^^^^^^^^^ doesn't have a size known at compile-time | = help: within `Dst<(dyn A + 'static)>`, the trait `Sized` is not implemented for `(dyn A + 'static)` note: required because it appears within the type `Dst<(dyn A + 'static)>` @@ -116,12 +98,10 @@ LL | struct Dst { = help: add `#![feature(trivial_bounds)]` to the crate attributes to enable error[E0277]: the size for values of type `str` cannot be known at compilation time - --> $DIR/feature-gate-trivial_bounds.rs:59:1 + --> $DIR/feature-gate-trivial_bounds.rs:59:30 | -LL | / fn return_str() -> str where str: Sized { -LL | | *"Sized".to_string().into_boxed_str() -LL | | } - | |_^ doesn't have a size known at compile-time +LL | fn return_str() -> str where str: Sized { + | ^^^^^^^^^^ doesn't have a size known at compile-time | = help: the trait `Sized` is not implemented for `str` = help: see issue #48214