rust-lang · bors · Sep 3, 2018 · Aug 31, 2018 · Aug 31, 2018
diff --git a/src/librustc/infer/error_reporting/mod.rs b/src/librustc/infer/error_reporting/mod.rs
@@ -68,6 +68,7 @@ use middle::region;
 use traits::{ObligationCause, ObligationCauseCode};
 use ty::{self, subst::Subst, Region, Ty, TyCtxt, TypeFoldable, TyKind};
 use ty::error::TypeError;
+use session::config::BorrowckMode;
 use syntax::ast::DUMMY_NODE_ID;
 use syntax_pos::{Pos, Span};
 use errors::{Applicability, DiagnosticBuilder, DiagnosticStyledString};
@@ -303,40 +304,16 @@ impl<'a, 'gcx, 'tcx> InferCtxt<'a, 'gcx, 'tcx> {
     ) {
         debug!("report_region_errors(): {} errors to start", errors.len());
 
-        if will_later_be_reported_by_nll &&
-            // FIXME: `use_mir_borrowck` seems wrong here...
-            self.tcx.use_mir_borrowck() &&
-            // ... this is a band-aid; may be better to explicitly
-            // match on every borrowck_mode variant to guide decision
-            // here.
-            !self.tcx.migrate_borrowck() {
-
-            // With `#![feature(nll)]`, we want to present a nice user
-            // experience, so don't even mention the errors from the
-            // AST checker.
-            if self.tcx.features().nll {
-                return;
+        // If the errors will later be reported by NLL, choose wether to display them or not based
+        // on the borrowck mode
+        if will_later_be_reported_by_nll {
+            match self.tcx.borrowck_mode() {
+                // If we're on AST or Migrate mode, report AST region errors
+                BorrowckMode::Ast | BorrowckMode::Migrate => {},
+                // If we're on MIR or Compare mode, don't report AST region errors as they should
+                // be reported by NLL
+                BorrowckMode::Compare | BorrowckMode::Mir => return,
             }
-
-            // But with nll, it's nice to have some note for later.
-            for error in errors {
-                match *error {
-                    RegionResolutionError::ConcreteFailure(ref origin, ..)
-                    | RegionResolutionError::GenericBoundFailure(ref origin, ..) => {
-                        self.tcx
-                            .sess
-                            .span_warn(origin.span(), "not reporting region error due to nll");
-                    }
-
-                    RegionResolutionError::SubSupConflict(ref rvo, ..) => {
-                        self.tcx
-                            .sess
-                            .span_warn(rvo.span(), "not reporting region error due to nll");
-                    }
-                }
-            }
-
-            return;
         }
 
         // try to pre-process the errors, which will group some of them

diff --git a/src/test/ui/associated-types/associated-types-project-from-hrtb-in-fn-body.nll.stderr b/src/test/ui/associated-types/associated-types-project-from-hrtb-in-fn-body.nll.stderr
@@ -1,9 +1,3 @@
-warning: not reporting region error due to nll
-  --> $DIR/associated-types-project-from-hrtb-in-fn-body.rs:32:12
-   |
-LL |     let z: I::A = if cond { x } else { y };
-   |            ^^^^
-
 error: unsatisfied lifetime constraints
   --> $DIR/associated-types-project-from-hrtb-in-fn-body.rs:32:29
    |

diff --git a/src/test/ui/associated-types/cache/project-fn-ret-contravariant.krisskross.nll.stderr b/src/test/ui/associated-types/cache/project-fn-ret-contravariant.krisskross.nll.stderr
@@ -1,15 +1,3 @@
-warning: not reporting region error due to nll
-  --> $DIR/project-fn-ret-contravariant.rs:53:16
-   |
-LL |    let a = bar(foo, y);
-   |                ^^^
-
-warning: not reporting region error due to nll
-  --> $DIR/project-fn-ret-contravariant.rs:54:16
-   |
-LL |    let b = bar(foo, x);
-   |                ^^^
-
 error: unsatisfied lifetime constraints
   --> $DIR/project-fn-ret-contravariant.rs:53:12
    |

diff --git a/src/test/ui/associated-types/cache/project-fn-ret-contravariant.transmute.nll.stderr b/src/test/ui/associated-types/cache/project-fn-ret-contravariant.transmute.nll.stderr
@@ -1,9 +1,3 @@
-warning: not reporting region error due to nll
-  --> $DIR/project-fn-ret-contravariant.rs:48:8
-   |
-LL |    bar(foo, x) //[transmute]~ ERROR E0495
-   |        ^^^
-
 error: unsatisfied lifetime constraints
   --> $DIR/project-fn-ret-contravariant.rs:48:4
    |

diff --git a/src/test/ui/associated-types/cache/project-fn-ret-invariant.krisskross.nll.stderr b/src/test/ui/associated-types/cache/project-fn-ret-invariant.krisskross.nll.stderr
@@ -1,15 +1,3 @@
-warning: not reporting region error due to nll
-  --> $DIR/project-fn-ret-invariant.rs:63:16
-   |
-LL |    let a = bar(foo, y); //[krisskross]~ ERROR E0623
-   |                ^^^
-
-warning: not reporting region error due to nll
-  --> $DIR/project-fn-ret-invariant.rs:64:16
-   |
-LL |    let b = bar(foo, x);
-   |                ^^^
-
 error: unsatisfied lifetime constraints
   --> $DIR/project-fn-ret-invariant.rs:63:12
    |

diff --git a/src/test/ui/associated-types/cache/project-fn-ret-invariant.oneuse.nll.stderr b/src/test/ui/associated-types/cache/project-fn-ret-invariant.oneuse.nll.stderr
@@ -1,9 +1,3 @@
-warning: not reporting region error due to nll
-  --> $DIR/project-fn-ret-invariant.rs:47:12
-   |
-LL |    let f = foo; // <-- No consistent type can be inferred for `f` here.
-   |            ^^^
-
 error: unsatisfied lifetime constraints
   --> $DIR/project-fn-ret-invariant.rs:48:12
    |

diff --git a/src/test/ui/associated-types/cache/project-fn-ret-invariant.transmute.nll.stderr b/src/test/ui/associated-types/cache/project-fn-ret-invariant.transmute.nll.stderr
@@ -1,9 +1,3 @@
-warning: not reporting region error due to nll
-  --> $DIR/project-fn-ret-invariant.rs:58:8
-   |
-LL |    bar(foo, x) //[transmute]~ ERROR E0495
-   |        ^^^
-
 error: unsatisfied lifetime constraints
   --> $DIR/project-fn-ret-invariant.rs:58:4
    |

diff --git a/src/test/ui/borrowck/borrowck-reborrow-from-shorter-lived-andmut.nll.stderr b/src/test/ui/borrowck/borrowck-reborrow-from-shorter-lived-andmut.nll.stderr
@@ -1,9 +1,3 @@
-warning: not reporting region error due to nll
-  --> $DIR/borrowck-reborrow-from-shorter-lived-andmut.rs:19:18
-   |
-LL |     S { pointer: &mut *p.pointer }
-   |                  ^^^^^^^^^^^^^^^
-
 error: unsatisfied lifetime constraints
   --> $DIR/borrowck-reborrow-from-shorter-lived-andmut.rs:19:5
    |

diff --git a/src/test/ui/borrowck/issue-45983.nll.stderr b/src/test/ui/borrowck/issue-45983.nll.stderr
@@ -1,9 +1,3 @@
-warning: not reporting region error due to nll
-  --> $DIR/issue-45983.rs:36:27
-   |
-LL |     give_any(|y| x = Some(y));
-   |                           ^
-
 error: borrowed data escapes outside of closure
   --> $DIR/issue-45983.rs:36:18
    |

diff --git a/src/test/ui/borrowck/issue-45983.rs b/src/test/ui/borrowck/issue-45983.rs
@@ -36,7 +36,6 @@ fn main() {
     give_any(|y| x = Some(y));
     //[ast]~^ ERROR borrowed data cannot be stored outside of its closure
     //[migrate]~^^ ERROR borrowed data cannot be stored outside of its closure
-    //[nll]~^^^ WARN not reporting region error due to nll
-    //[nll]~| ERROR borrowed data escapes outside of closure
+    //[nll]~^^^ ERROR borrowed data escapes outside of closure
     //[nll]~| ERROR cannot assign to `x`, as it is not declared as mutable
 }
diff --git a/src/test/ui/borrowck/issue-7573.nll.stderr b/src/test/ui/borrowck/issue-7573.nll.stderr
@@ -1,9 +1,3 @@
-warning: not reporting region error due to nll
-  --> $DIR/issue-7573.rs:27:31
-   |
-LL |     let mut lines_to_use: Vec<&CrateId> = Vec::new();
-   |                               ^
-
 error: borrowed data escapes outside of closure
   --> $DIR/issue-7573.rs:32:9
    |

diff --git a/src/test/ui/borrowck/regions-escape-bound-fn-2.nll.stderr b/src/test/ui/borrowck/regions-escape-bound-fn-2.nll.stderr
@@ -1,9 +1,3 @@
-warning: not reporting region error due to nll
-  --> $DIR/regions-escape-bound-fn-2.rs:18:27
-   |
-LL |     with_int(|y| x = Some(y));
-   |                           ^
-
 error: borrowed data escapes outside of closure
   --> $DIR/regions-escape-bound-fn-2.rs:18:18
    |

diff --git a/src/test/ui/borrowck/regions-escape-bound-fn.nll.stderr b/src/test/ui/borrowck/regions-escape-bound-fn.nll.stderr
@@ -1,9 +1,3 @@
-warning: not reporting region error due to nll
-  --> $DIR/regions-escape-bound-fn.rs:18:22
-   |
-LL |     with_int(|y| x = Some(y));
-   |                      ^^^^^^^
-
 error: borrowed data escapes outside of closure
   --> $DIR/regions-escape-bound-fn.rs:18:18
    |

diff --git a/src/test/ui/borrowck/regions-escape-unboxed-closure.nll.stderr b/src/test/ui/borrowck/regions-escape-unboxed-closure.nll.stderr
@@ -1,9 +1,3 @@
-warning: not reporting region error due to nll
-  --> $DIR/regions-escape-unboxed-closure.rs:16:27
-   |
-LL |     with_int(&mut |y| x = Some(y));
-   |                           ^^^^^^^
-
 error: borrowed data escapes outside of closure
   --> $DIR/regions-escape-unboxed-closure.rs:16:23
    |

diff --git a/src/test/ui/closure-expected-type/expect-fn-supply-fn.nll.stderr b/src/test/ui/closure-expected-type/expect-fn-supply-fn.nll.stderr
@@ -1,9 +1,3 @@
-warning: not reporting region error due to nll
-  --> $DIR/expect-fn-supply-fn.rs:24:52
-   |
-LL |     with_closure_expecting_fn_with_free_region(|x: fn(&'x u32), y| {});
-   |                                                    ^^^^^^^^^^^
-
 error[E0631]: type mismatch in closure arguments
   --> $DIR/expect-fn-supply-fn.rs:40:5
    |

diff --git a/src/test/ui/closures/closure-bounds-static-cant-capture-borrowed.nll.stderr b/src/test/ui/closures/closure-bounds-static-cant-capture-borrowed.nll.stderr
@@ -1,13 +1,3 @@
-warning: not reporting region error due to nll
-  --> $DIR/closure-bounds-static-cant-capture-borrowed.rs:15:9
-   |
-LL |       bar(|| {
-   |  _________^
-LL | |         //~^ ERROR explicit lifetime required in the type of `x` [E0621]
-LL | |         let _ = x;
-LL | |     })
-   | |_____^
-
 error[E0621]: explicit lifetime required in the type of `x`
   --> $DIR/closure-bounds-static-cant-capture-borrowed.rs:15:5
    |

diff --git a/src/test/ui/closures/closure-expected-type/expect-region-supply-region.nll.stderr b/src/test/ui/closures/closure-expected-type/expect-region-supply-region.nll.stderr
@@ -1,27 +1,3 @@
-warning: not reporting region error due to nll
-  --> $DIR/expect-region-supply-region.rs:28:13
-   |
-LL |         f = Some(x); //~ ERROR borrowed data cannot be stored outside of its closure
-   |             ^^^^^^^
-
-warning: not reporting region error due to nll
-  --> $DIR/expect-region-supply-region.rs:38:13
-   |
-LL |         f = Some(x); //~ ERROR borrowed data cannot be stored outside of its closure
-   |             ^^^^^^^
-
-warning: not reporting region error due to nll
-  --> $DIR/expect-region-supply-region.rs:47:33
-   |
-LL |     closure_expecting_bound(|x: &'x u32| {
-   |                                 ^^^^^^^
-
-warning: not reporting region error due to nll
-  --> $DIR/expect-region-supply-region.rs:52:13
-   |
-LL |         f = Some(x);
-   |             ^^^^^^^
-
 error: borrowed data escapes outside of closure
   --> $DIR/expect-region-supply-region.rs:28:9
    |

diff --git a/src/test/ui/error-codes/E0621-does-not-trigger-for-closures.nll.stderr b/src/test/ui/error-codes/E0621-does-not-trigger-for-closures.nll.stderr
@@ -1,9 +1,3 @@
-warning: not reporting region error due to nll
-  --> $DIR/E0621-does-not-trigger-for-closures.rs:25:5
-   |
-LL |     invoke(&x, |a, b| if a > b { a } else { b }); //~ ERROR E0495
-   |     ^^^^^^
-
 error: unsatisfied lifetime constraints
   --> $DIR/E0621-does-not-trigger-for-closures.rs:25:45
    |

diff --git a/src/test/ui/existential_types/generic_type_does_not_live_long_enough.nll.stderr b/src/test/ui/existential_types/generic_type_does_not_live_long_enough.nll.stderr
@@ -7,12 +7,6 @@ LL |     let z: i32 = x; //~ ERROR mismatched types
    = note: expected type `i32`
               found type `WrongGeneric::<&{integer}>`
 
-warning: not reporting region error due to nll
-  --> $DIR/generic_type_does_not_live_long_enough.rs:19:1
-   |
-LL | existential type WrongGeneric<T>: 'static;
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-
 error: aborting due to previous error
 
 For more information about this error, try `rustc --explain E0308`.
diff --git a/src/test/ui/hr-subtype/hr-subtype.free_inv_x_vs_free_inv_y.nll.stderr b/src/test/ui/hr-subtype/hr-subtype.free_inv_x_vs_free_inv_y.nll.stderr
@@ -1,23 +1,3 @@
-warning: not reporting region error due to nll
-  --> $DIR/hr-subtype.rs:43:26
-   |
-LL |               gimme::<$t2>(None::<$t1>);
-   |                            ^^^^^^^^^^^
-...
-LL | / check! { free_inv_x_vs_free_inv_y: (fn(Inv<'x>),
-LL | |                                     fn(Inv<'y>)) }
-   | |__________________________________________________- in this macro invocation
-
-warning: not reporting region error due to nll
-  --> $DIR/hr-subtype.rs:49:26
-   |
-LL |               gimme::<$t1>(None::<$t2>);
-   |                            ^^^^^^^^^^^
-...
-LL | / check! { free_inv_x_vs_free_inv_y: (fn(Inv<'x>),
-LL | |                                     fn(Inv<'y>)) }
-   | |__________________________________________________- in this macro invocation
-
 error: unsatisfied lifetime constraints
   --> $DIR/hr-subtype.rs:43:13
    |

diff --git a/src/test/ui/hr-subtype/hr-subtype.free_x_vs_free_y.nll.stderr b/src/test/ui/hr-subtype/hr-subtype.free_x_vs_free_y.nll.stderr
@@ -1,13 +1,3 @@
-warning: not reporting region error due to nll
-  --> $DIR/hr-subtype.rs:49:26
-   |
-LL |               gimme::<$t1>(None::<$t2>);
-   |                            ^^^^^^^^^^^
-...
-LL | / check! { free_x_vs_free_y: (fn(&'x u32),
-LL | |                             fn(&'y u32)) }
-   | |__________________________________________- in this macro invocation
-
 error: unsatisfied lifetime constraints
   --> $DIR/hr-subtype.rs:49:13
    |

diff --git a/src/test/ui/impl-header-lifetime-elision/dyn-trait.nll.stderr b/src/test/ui/impl-header-lifetime-elision/dyn-trait.nll.stderr
@@ -1,9 +1,3 @@
-warning: not reporting region error due to nll
-  --> $DIR/dyn-trait.rs:32:16
-   |
-LL |     static_val(x); //~ ERROR cannot infer
-   |                ^
-
 error: borrowed data escapes outside of function
   --> $DIR/dyn-trait.rs:32:5
    |

diff --git a/src/test/ui/impl-trait/must_outlive_least_region_or_bound.nll.stderr b/src/test/ui/impl-trait/must_outlive_least_region_or_bound.nll.stderr
@@ -1,33 +1,3 @@
-warning: not reporting region error due to nll
-  --> $DIR/must_outlive_least_region_or_bound.rs:13:35
-   |
-LL | fn elided(x: &i32) -> impl Copy { x }
-   |                                   ^
-
-warning: not reporting region error due to nll
-  --> $DIR/must_outlive_least_region_or_bound.rs:16:44
-   |
-LL | fn explicit<'a>(x: &'a i32) -> impl Copy { x }
-   |                                            ^
-
-warning: not reporting region error due to nll
-  --> $DIR/must_outlive_least_region_or_bound.rs:22:69
-   |
-LL | fn with_bound<'a>(x: &'a i32) -> impl LifetimeTrait<'a> + 'static { x }
-   |                                                                     ^
-
-warning: not reporting region error due to nll
-  --> $DIR/must_outlive_least_region_or_bound.rs:29:5
-   |
-LL |     move |_| println!("{}", y)
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^
-
-warning: not reporting region error due to nll
-  --> $DIR/must_outlive_least_region_or_bound.rs:32:51
-   |
-LL | fn ty_param_wont_outlive_static<T:Debug>(x: T) -> impl Debug + 'static {
-   |                                                   ^^^^^^^^^^^^^^^^^^^^
-
 error[E0621]: explicit lifetime required in the type of `x`
   --> $DIR/must_outlive_least_region_or_bound.rs:13:35
    |

diff --git a/src/test/ui/impl-trait/static-return-lifetime-infered.nll.stderr b/src/test/ui/impl-trait/static-return-lifetime-infered.nll.stderr
@@ -1,15 +1,3 @@
-warning: not reporting region error due to nll
-  --> $DIR/static-return-lifetime-infered.rs:17:16
-   |
-LL |         self.x.iter().map(|a| a.0)
-   |                ^^^^
-
-warning: not reporting region error due to nll
-  --> $DIR/static-return-lifetime-infered.rs:21:16
-   |
-LL |         self.x.iter().map(|a| a.0)
-   |                ^^^^
-
 error: unsatisfied lifetime constraints
   --> $DIR/static-return-lifetime-infered.rs:17:9
    |

diff --git a/src/test/ui/impl-trait/type_parameters_captured.nll.stderr b/src/test/ui/impl-trait/type_parameters_captured.nll.stderr
@@ -1,9 +1,3 @@
-warning: not reporting region error due to nll
-  --> $DIR/type_parameters_captured.rs:17:20
-   |
-LL | fn foo<T>(x: T) -> impl Any + 'static {
-   |                    ^^^^^^^^^^^^^^^^^^
-
 error[E0310]: the parameter type `T` may not live long enough
   --> $DIR/type_parameters_captured.rs:19:5
    |

diff --git a/src/test/ui/in-band-lifetimes/mismatched.nll.stderr b/src/test/ui/in-band-lifetimes/mismatched.nll.stderr
@@ -1,15 +1,3 @@
-warning: not reporting region error due to nll
-  --> $DIR/mismatched.rs:14:42
-   |
-LL | fn foo(x: &'a u32, y: &u32) -> &'a u32 { y } //~ ERROR explicit lifetime required
-   |                                          ^
-
-warning: not reporting region error due to nll
-  --> $DIR/mismatched.rs:16:46
-   |
-LL | fn foo2(x: &'a u32, y: &'b u32) -> &'a u32 { y } //~ ERROR lifetime mismatch
-   |                                              ^
-
 error[E0621]: explicit lifetime required in the type of `y`
   --> $DIR/mismatched.rs:14:42
    |