Add an explicit Span field to OutlivesConstraint

Previously, we would retrieve the span from the `Body` using the `locations` field. However, we may end up changing the `locations` field when moving a constraint from a promoted to a different body. We now store the original `Span` in a dedication field, so that changes to the `locations` do not affect the quality of our diagnostics.
2022-04-19 20:53:35 -04:00 · 2022-04-19 20:53:35 -04:00 · 611a06a375
parent 4ca19e09d3
commit 611a06a375
16 changed files with 58 additions and 64 deletions
--- a/compiler/rustc_borrowck/src/constraints/graph.rs
+++ b/compiler/rustc_borrowck/src/constraints/graph.rs
@ -156,6 +156,7 @@ impl<'s, 'tcx, D: ConstraintGraphDirecton> Iterator for Edges<'s, 'tcx, D> {
                sup: self.static_region,
                sub: next_static_idx.into(),
                locations: Locations::All(DUMMY_SP),
+                span: DUMMY_SP,
                category: ConstraintCategory::Internal,
                variance_info: VarianceDiagInfo::default(),
            })
--- a/compiler/rustc_borrowck/src/constraints/mod.rs
+++ b/compiler/rustc_borrowck/src/constraints/mod.rs
@ -2,6 +2,7 @@ use rustc_data_structures::graph::scc::Sccs;
 use rustc_index::vec::IndexVec;
 use rustc_middle::mir::ConstraintCategory;
 use rustc_middle::ty::{RegionVid, VarianceDiagInfo};
+use rustc_span::Span;
 use std::fmt;
 use std::ops::Index;

@ -87,6 +88,12 @@ pub struct OutlivesConstraint<'tcx> {
    /// Where did this constraint arise?
    pub locations: Locations,

+    /// The `Span` associated with the creation of this constraint.
+    /// This should be used in preference to obtaining the span from
+    /// `locations`, since the `locations` may give a poor span
+    /// in some cases (e.g. converting a constraint from a promoted).
+    pub span: Span,
+
    /// What caused this constraint?
    pub category: ConstraintCategory,

--- a/compiler/rustc_borrowck/src/region_infer/dump_mir.rs
+++ b/compiler/rustc_borrowck/src/region_infer/dump_mir.rs
@ -74,14 +74,18 @@ impl<'tcx> RegionInferenceContext<'tcx> {
        let mut constraints: Vec<_> = self.constraints.outlives().iter().collect();
        constraints.sort_by_key(|c| (c.sup, c.sub));
        for constraint in &constraints {
-            let OutlivesConstraint { sup, sub, locations, category, variance_info: _ } = constraint;
+            let OutlivesConstraint { sup, sub, locations, category, span, variance_info: _ } =
+                constraint;
            let (name, arg) = match locations {
                Locations::All(span) => {
                    ("All", tcx.sess.source_map().span_to_embeddable_string(*span))
                }
                Locations::Single(loc) => ("Single", format!("{:?}", loc)),
            };
-            with_msg(&format!("{:?}: {:?} due to {:?} at {}({})", sup, sub, category, name, arg))?;
+            with_msg(&format!(
+                "{:?}: {:?} due to {:?} at {}({}) ({:?}",
+                sup, sub, category, name, arg, span
+            ))?;
        }

        Ok(())
--- a/compiler/rustc_borrowck/src/region_infer/mod.rs
+++ b/compiler/rustc_borrowck/src/region_infer/mod.rs
@ -1733,7 +1733,7 @@ impl<'tcx> RegionInferenceContext<'tcx> {

    crate fn retrieve_closure_constraint_info(
        &self,
-        body: &Body<'tcx>,
+        _body: &Body<'tcx>,
        constraint: &OutlivesConstraint<'tcx>,
    ) -> BlameConstraint<'tcx> {
        let loc = match constraint.locations {
@ -1760,7 +1760,7 @@ impl<'tcx> RegionInferenceContext<'tcx> {
            .unwrap_or(BlameConstraint {
                category: constraint.category,
                from_closure: false,
-                cause: ObligationCause::dummy_with_span(body.source_info(loc).span),
+                cause: ObligationCause::dummy_with_span(constraint.span),
                variance_info: constraint.variance_info,
            })
    }
@ -1869,6 +1869,7 @@ impl<'tcx> RegionInferenceContext<'tcx> {
                    sup: r,
                    sub: constraint.min_choice,
                    locations: Locations::All(p_c.definition_span),
+                    span: p_c.definition_span,
                    category: ConstraintCategory::OpaqueType,
                    variance_info: ty::VarianceDiagInfo::default(),
                };
@ -2017,7 +2018,7 @@ impl<'tcx> RegionInferenceContext<'tcx> {
                        category: constraint.category,
                        from_closure: false,
                        cause: ObligationCause::new(
-                            constraint.locations.span(body),
+                            constraint.span,
                            CRATE_HIR_ID,
                            cause_code.clone(),
                        ),
--- a/compiler/rustc_borrowck/src/type_check/constraint_conversion.rs
+++ b/compiler/rustc_borrowck/src/type_check/constraint_conversion.rs
@ -8,7 +8,7 @@ use rustc_middle::mir::ConstraintCategory;
 use rustc_middle::ty::subst::GenericArgKind;
 use rustc_middle::ty::TypeFoldable;
 use rustc_middle::ty::{self, TyCtxt};
-use rustc_span::DUMMY_SP;
+use rustc_span::{Span, DUMMY_SP};

 use crate::{
    constraints::OutlivesConstraint,
@ -26,6 +26,7 @@ crate struct ConstraintConversion<'a, 'tcx> {
    implicit_region_bound: Option<ty::Region<'tcx>>,
    param_env: ty::ParamEnv<'tcx>,
    locations: Locations,
+    span: Span,
    category: ConstraintCategory,
    constraints: &'a mut MirTypeckRegionConstraints<'tcx>,
 }
@ -38,6 +39,7 @@ impl<'a, 'tcx> ConstraintConversion<'a, 'tcx> {
        implicit_region_bound: Option<ty::Region<'tcx>>,
        param_env: ty::ParamEnv<'tcx>,
        locations: Locations,
+        span: Span,
        category: ConstraintCategory,
        constraints: &'a mut MirTypeckRegionConstraints<'tcx>,
    ) -> Self {
@ -49,6 +51,7 @@ impl<'a, 'tcx> ConstraintConversion<'a, 'tcx> {
            implicit_region_bound,
            param_env,
            locations,
+            span,
            category,
            constraints,
        }
@ -153,6 +156,7 @@ impl<'a, 'tcx> ConstraintConversion<'a, 'tcx> {
        self.constraints.outlives_constraints.push(OutlivesConstraint {
            locations: self.locations,
            category: self.category,
+            span: self.span,
            sub,
            sup,
            variance_info: ty::VarianceDiagInfo::default(),
--- a/compiler/rustc_borrowck/src/type_check/free_region_relations.rs
+++ b/compiler/rustc_borrowck/src/type_check/free_region_relations.rs
@ -316,6 +316,7 @@ impl<'tcx> UniversalRegionRelationsBuilder<'_, 'tcx> {
                self.implicit_region_bound,
                self.param_env,
                Locations::All(DUMMY_SP),
+                DUMMY_SP,
                ConstraintCategory::Internal,
                &mut self.constraints,
            )
--- a/compiler/rustc_borrowck/src/type_check/input_output.rs
+++ b/compiler/rustc_borrowck/src/type_check/input_output.rs
@ -235,6 +235,7 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
                Some(self.implicit_region_bound),
                self.param_env,
                Locations::All(DUMMY_SP),
+                DUMMY_SP,
                ConstraintCategory::Internal,
                &mut self.borrowck_context.constraints,
            )
--- a/compiler/rustc_borrowck/src/type_check/mod.rs
+++ b/compiler/rustc_borrowck/src/type_check/mod.rs
@ -1141,6 +1141,7 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
            Some(self.implicit_region_bound),
            self.param_env,
            locations,
+            locations.span(self.body),
            category,
            &mut self.borrowck_context.constraints,
        )
@ -2401,6 +2402,7 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
                                sup: ref_region.to_region_vid(),
                                sub: borrow_region.to_region_vid(),
                                locations: location.to_locations(),
+                                span: location.to_locations().span(body),
                                category,
                                variance_info: ty::VarianceDiagInfo::default(),
                            });
--- a/compiler/rustc_borrowck/src/type_check/relate_tys.rs
+++ b/compiler/rustc_borrowck/src/type_check/relate_tys.rs
@ -116,6 +116,7 @@ impl<'tcx> TypeRelatingDelegate<'tcx> for NllTypeRelatingDelegate<'_, '_, 'tcx>
                sup,
                sub,
                locations: self.locations,
+                span: self.locations.span(self.type_checker.body),
                category: self.category,
                variance_info: info,
            },
--- a/src/test/mir-opt/nll/named_lifetimes_basic.use_x.nll.0.mir
+++ b/src/test/mir-opt/nll/named_lifetimes_basic.use_x.nll.0.mir
@ -25,14 +25,14 @@
 | '_#2r live at {bb0[0..=1]}
 | '_#3r live at {bb0[0..=1]}
 | '_#4r live at {bb0[0..=1]}
-| '_#1r: '_#6r due to BoringNoLocation at All($DIR/named-lifetimes-basic.rs:12:26: 12:27)
-| '_#1r: '_#8r due to BoringNoLocation at All($DIR/named-lifetimes-basic.rs:12:54: 12:55)
-| '_#2r: '_#7r due to BoringNoLocation at All($DIR/named-lifetimes-basic.rs:12:42: 12:43)
-| '_#3r: '_#9r due to BoringNoLocation at All($DIR/named-lifetimes-basic.rs:12:66: 12:67)
-| '_#6r: '_#1r due to BoringNoLocation at All($DIR/named-lifetimes-basic.rs:12:26: 12:27)
-| '_#7r: '_#2r due to BoringNoLocation at All($DIR/named-lifetimes-basic.rs:12:42: 12:43)
-| '_#8r: '_#1r due to BoringNoLocation at All($DIR/named-lifetimes-basic.rs:12:54: 12:55)
-| '_#9r: '_#3r due to BoringNoLocation at All($DIR/named-lifetimes-basic.rs:12:66: 12:67)
+| '_#1r: '_#6r due to BoringNoLocation at All($DIR/named-lifetimes-basic.rs:12:26: 12:27) ($DIR/named-lifetimes-basic.rs:12:26: 12:27 (#0)
+| '_#1r: '_#8r due to BoringNoLocation at All($DIR/named-lifetimes-basic.rs:12:54: 12:55) ($DIR/named-lifetimes-basic.rs:12:54: 12:55 (#0)
+| '_#2r: '_#7r due to BoringNoLocation at All($DIR/named-lifetimes-basic.rs:12:42: 12:43) ($DIR/named-lifetimes-basic.rs:12:42: 12:43 (#0)
+| '_#3r: '_#9r due to BoringNoLocation at All($DIR/named-lifetimes-basic.rs:12:66: 12:67) ($DIR/named-lifetimes-basic.rs:12:66: 12:67 (#0)
+| '_#6r: '_#1r due to BoringNoLocation at All($DIR/named-lifetimes-basic.rs:12:26: 12:27) ($DIR/named-lifetimes-basic.rs:12:26: 12:27 (#0)
+| '_#7r: '_#2r due to BoringNoLocation at All($DIR/named-lifetimes-basic.rs:12:42: 12:43) ($DIR/named-lifetimes-basic.rs:12:42: 12:43 (#0)
+| '_#8r: '_#1r due to BoringNoLocation at All($DIR/named-lifetimes-basic.rs:12:54: 12:55) ($DIR/named-lifetimes-basic.rs:12:54: 12:55 (#0)
+| '_#9r: '_#3r due to BoringNoLocation at All($DIR/named-lifetimes-basic.rs:12:66: 12:67) ($DIR/named-lifetimes-basic.rs:12:66: 12:67 (#0)
 |
 fn use_x(_1: &'_#6r mut i32, _2: &'_#7r u32, _3: &'_#8r u32, _4: &'_#9r u32) -> bool {
    debug w => _1;                       // in scope 0 at $DIR/named-lifetimes-basic.rs:12:26: 12:27
--- a/src/test/mir-opt/nll/region_subtyping_basic.main.nll.0.32bit.mir
+++ b/src/test/mir-opt/nll/region_subtyping_basic.main.nll.0.32bit.mir
@ -18,8 +18,8 @@
 | '_#3r live at {bb1[0]}
 | '_#4r live at {bb1[1..=3]}
 | '_#5r live at {bb1[4..=7], bb2[0..=2]}
-| '_#3r: '_#4r due to Assignment at Single(bb1[0])
-| '_#4r: '_#5r due to Assignment at Single(bb1[3])
+| '_#3r: '_#4r due to Assignment at Single(bb1[0]) ($DIR/region-subtyping-basic.rs:18:13: 18:18 (#0)
+| '_#4r: '_#5r due to Assignment at Single(bb1[3]) ($DIR/region-subtyping-basic.rs:19:13: 19:14 (#0)
 |
 fn main() -> () {
    let mut _0: ();                      // return place in scope 0 at $DIR/region-subtyping-basic.rs:16:11: 16:11
--- a/src/test/mir-opt/nll/region_subtyping_basic.main.nll.0.64bit.mir
+++ b/src/test/mir-opt/nll/region_subtyping_basic.main.nll.0.64bit.mir
@ -18,8 +18,8 @@
 | '_#3r live at {bb1[0]}
 | '_#4r live at {bb1[1..=3]}
 | '_#5r live at {bb1[4..=7], bb2[0..=2]}
-| '_#3r: '_#4r due to Assignment at Single(bb1[0])
-| '_#4r: '_#5r due to Assignment at Single(bb1[3])
+| '_#3r: '_#4r due to Assignment at Single(bb1[0]) ($DIR/region-subtyping-basic.rs:18:13: 18:18 (#0)
+| '_#4r: '_#5r due to Assignment at Single(bb1[3]) ($DIR/region-subtyping-basic.rs:19:13: 19:14 (#0)
 |
 fn main() -> () {
    let mut _0: ();                      // return place in scope 0 at $DIR/region-subtyping-basic.rs:16:11: 16:11
--- a/src/test/mir-opt/storage_ranges.main.nll.0.mir
+++ b/src/test/mir-opt/storage_ranges.main.nll.0.mir
@ -16,7 +16,7 @@
 | '_#1r live at {bb0[0..=22]}
 | '_#3r live at {bb0[10]}
 | '_#4r live at {bb0[11]}
-| '_#3r: '_#4r due to Assignment at Single(bb0[10])
+| '_#3r: '_#4r due to Assignment at Single(bb0[10]) ($DIR/storage_ranges.rs:6:17: 6:25 (#0)
 |
 fn main() -> () {
    let mut _0: ();                      // return place in scope 0 at $DIR/storage_ranges.rs:3:11: 3:11
--- a/src/test/ui/rfc1623.base.stderr
+++ b/src/test/ui/rfc1623.base.stderr
@ -1,5 +1,5 @@
 error: implementation of `FnOnce` is not general enough
-  --> $DIR/rfc1623.rs:36:8
+  --> $DIR/rfc1623.rs:32:8
   |
 LL |     f: &id,
   |        ^^^ implementation of `FnOnce` is not general enough
--- a/src/test/ui/rfc1623.nll.stderr
+++ b/src/test/ui/rfc1623.nll.stderr
@ -1,63 +1,35 @@
 error[E0308]: mismatched types
-  --> $DIR/rfc1623.rs:29:35
+  --> $DIR/rfc1623.rs:32:8
   |
-LL |   static SOME_STRUCT: &SomeStruct = &SomeStruct {
-   |  ___________________________________^
-LL | |
-LL | |
-LL | |
-...  |
-LL | |
-LL | | };
-   | |_^ one type is more general than the other
+LL |     f: &id,
+   |        ^^^ one type is more general than the other
   |
   = note: expected type `for<'a, 'b> Fn<(&'a Foo<'b>,)>`
              found type `Fn<(&Foo<'_>,)>`

 error[E0308]: mismatched types
-  --> $DIR/rfc1623.rs:29:35
+  --> $DIR/rfc1623.rs:32:8
   |
-LL |   static SOME_STRUCT: &SomeStruct = &SomeStruct {
-   |  ___________________________________^
-LL | |
-LL | |
-LL | |
-...  |
-LL | |
-LL | | };
-   | |_^ one type is more general than the other
+LL |     f: &id,
+   |        ^^^ one type is more general than the other
   |
   = note: expected type `for<'a, 'b> Fn<(&'a Foo<'b>,)>`
              found type `Fn<(&Foo<'_>,)>`

 error: implementation of `FnOnce` is not general enough
-  --> $DIR/rfc1623.rs:29:35
+  --> $DIR/rfc1623.rs:32:8
   |
-LL |   static SOME_STRUCT: &SomeStruct = &SomeStruct {
-   |  ___________________________________^
-LL | |
-LL | |
-LL | |
-...  |
-LL | |
-LL | | };
-   | |_^ implementation of `FnOnce` is not general enough
+LL |     f: &id,
+   |        ^^^ implementation of `FnOnce` is not general enough
   |
   = note: `fn(&'2 Foo<'_>) -> &'2 Foo<'_> {id::<&'2 Foo<'_>>}` must implement `FnOnce<(&'1 Foo<'b>,)>`, for any lifetime `'1`...
   = note: ...but it actually implements `FnOnce<(&'2 Foo<'_>,)>`, for some specific lifetime `'2`

 error: implementation of `FnOnce` is not general enough
-  --> $DIR/rfc1623.rs:29:35
+  --> $DIR/rfc1623.rs:32:8
   |
-LL |   static SOME_STRUCT: &SomeStruct = &SomeStruct {
-   |  ___________________________________^
-LL | |
-LL | |
-LL | |
-...  |
-LL | |
-LL | | };
-   | |_^ implementation of `FnOnce` is not general enough
+LL |     f: &id,
+   |        ^^^ implementation of `FnOnce` is not general enough
   |
   = note: `fn(&Foo<'2>) -> &Foo<'2> {id::<&Foo<'2>>}` must implement `FnOnce<(&'a Foo<'1>,)>`, for any lifetime `'1`...
   = note: ...but it actually implements `FnOnce<(&Foo<'2>,)>`, for some specific lifetime `'2`
--- a/src/test/ui/rfc1623.rs
+++ b/src/test/ui/rfc1623.rs
@ -27,14 +27,14 @@ fn id<T>(t: T) -> T {
 }

 static SOME_STRUCT: &SomeStruct = &SomeStruct {
-    //[nll]~^ ERROR mismatched types
-    //[nll]~| ERROR mismatched types
-    //[nll]~| ERROR implementation of `FnOnce` is not general enough
-    //[nll]~| ERROR implementation of `FnOnce` is not general enough
    foo: &Foo { bools: &[false, true] },
    bar: &Bar { bools: &[true, true] },
    f: &id,
    //[base]~^ ERROR implementation of `FnOnce` is not general enough
+    //[nll]~^^ ERROR mismatched types
+    //[nll]~| ERROR mismatched types
+    //[nll]~| ERROR implementation of `FnOnce` is not general enough
+    //[nll]~| ERROR implementation of `FnOnce` is not general enough
 };

 // very simple test for a 'static static with default lifetime