move annotate onto a method of UniversalRegions

This allows it to print out the "late-bound regions" from the closure
context more easily. Besides, all the state that is being printed it
is private to the `UniversalRegions`.

src/librustc_mir/borrow_check/nll/mod.rs

@@ -276,7 +276,7 @@ fn dump_annotation<'a, 'gcx, 'tcx>(
     infcx: &InferCtxt<'a, 'gcx, 'tcx>,
     mir: &Mir<'tcx>,
     mir_def_id: DefId,
-    regioncx: &RegionInferenceContext,
+    regioncx: &RegionInferenceContext<'tcx>,
     closure_region_requirements: &Option<ClosureRegionRequirements>,
     errors_buffer: &mut Vec<Diagnostic>,
 ) {
@@ -299,7 +299,7 @@ fn dump_annotation<'a, 'gcx, 'tcx>(
             .diagnostic()
             .span_note_diag(mir.span, "External requirements");
 
-        regioncx.annotate(&mut err);
+        regioncx.annotate(tcx, &mut err);
 
         err.note(&format!(
             "number of external vids: {}",
@@ -319,7 +319,7 @@ fn dump_annotation<'a, 'gcx, 'tcx>(
             .sess
             .diagnostic()
             .span_note_diag(mir.span, "No external requirements");
-        regioncx.annotate(&mut err);
+        regioncx.annotate(tcx, &mut err);
 
         err.buffer(errors_buffer);
     }

src/librustc_mir/borrow_check/nll/region_infer/annotation.rs

@@ -1,56 +0,0 @@
-// Copyright 2017 The Rust Project Developers. See the COPYRIGHT
-// file at the top-level directory of this distribution and at
-// http://rust-lang.org/COPYRIGHT.
-//
-// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
-// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
-// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
-// option. This file may not be copied, modified, or distributed
-// except according to those terms.
-
-//! As part of the NLL unit tests, you can annotate a function with
-//! `#[rustc_regions]`, and we will emit information about the region
-//! inference context and -- in particular -- the external constraints
-//! that this region imposes on others. The methods in this file
-//! handle the part about dumping the inference context internal
-//! state.
-
-use borrow_check::nll::region_infer::RegionInferenceContext;
-use borrow_check::nll::universal_regions::DefiningTy;
-use rustc_errors::DiagnosticBuilder;
-
-impl<'tcx> RegionInferenceContext<'tcx> {
-    /// Write out our state into the `.mir` files.
-    pub(crate) fn annotate(&self, err: &mut DiagnosticBuilder<'_>) {
-        match self.universal_regions.defining_ty {
-            DefiningTy::Closure(def_id, substs) => {
-                err.note(&format!(
-                    "defining type: {:?} with closure substs {:#?}",
-                    def_id,
-                    &substs.substs[..]
-                ));
-            }
-            DefiningTy::Generator(def_id, substs, _) => {
-                err.note(&format!(
-                    "defining type: {:?} with generator substs {:#?}",
-                    def_id,
-                    &substs.substs[..]
-                ));
-            }
-            DefiningTy::FnDef(def_id, substs) => {
-                err.note(&format!(
-                    "defining type: {:?} with substs {:#?}",
-                    def_id,
-                    &substs[..]
-                ));
-            }
-            DefiningTy::Const(def_id, substs) => {
-                err.note(&format!(
-                    "defining constant type: {:?} with substs {:#?}",
-                    def_id,
-                    &substs[..]
-                ));
-            }
-        }
-    }
-}

src/librustc_mir/borrow_check/nll/region_infer/mod.rs

@@ -29,11 +29,10 @@ use rustc::util::common;
 use rustc_data_structures::graph::scc::Sccs;
 use rustc_data_structures::indexed_set::IdxSet;
 use rustc_data_structures::indexed_vec::IndexVec;
-use rustc_errors::Diagnostic;
+use rustc_errors::{DiagnosticBuilder, Diagnostic};
 
 use std::rc::Rc;
 
-mod annotation;
 mod dump_mir;
 mod error_reporting;
 mod graphviz;
@@ -359,6 +358,11 @@ impl<'tcx> RegionInferenceContext<'tcx> {
         self.universal_regions.to_region_vid(r)
     }
 
+    /// Add annotations for `#[rustc_regions]`; see `UniversalRegions::annotate`.
+    crate fn annotate(&self, tcx: TyCtxt<'_, '_, 'tcx>, err: &mut DiagnosticBuilder<'_>) {
+        self.universal_regions.annotate(tcx, err)
+    }
+
     /// Returns true if the region `r` contains the point `p`.
     ///
     /// Panics if called before `solve()` executes,

src/librustc_mir/borrow_check/nll/universal_regions.rs

@@ -31,6 +31,7 @@ use rustc::ty::subst::Substs;
 use rustc::ty::{self, ClosureSubsts, GeneratorSubsts, RegionVid, Ty, TyCtxt};
 use rustc::util::nodemap::FxHashMap;
 use rustc_data_structures::indexed_vec::{Idx, IndexVec};
+use rustc_errors::DiagnosticBuilder;
 use std::iter;
 use syntax::ast;
 
@@ -310,6 +311,63 @@ impl<'tcx> UniversalRegions<'tcx> {
     pub fn to_region_vid(&self, r: ty::Region<'tcx>) -> RegionVid {
         self.indices.to_region_vid(r)
     }
+
+    /// As part of the NLL unit tests, you can annotate a function with
+    /// `#[rustc_regions]`, and we will emit information about the region
+    /// inference context and -- in particular -- the external constraints
+    /// that this region imposes on others. The methods in this file
+    /// handle the part about dumping the inference context internal
+    /// state.
+    crate fn annotate(&self, tcx: TyCtxt<'_, '_, 'tcx>, err: &mut DiagnosticBuilder<'_>) {
+        match self.defining_ty {
+            DefiningTy::Closure(def_id, substs) => {
+                err.note(&format!(
+                    "defining type: {:?} with closure substs {:#?}",
+                    def_id,
+                    &substs.substs[..]
+                ));
+
+                let closure_base_def_id = tcx.closure_base_def_id(def_id);
+                for_each_late_bound_region_defined_on(tcx, closure_base_def_id, |r| {
+                    err.note(&format!(
+                        "late-bound region {:?} is {:?}",
+                        r,
+                        self.to_region_vid(r),
+                    ));
+                });
+            }
+            DefiningTy::Generator(def_id, substs, _) => {
+                err.note(&format!(
+                    "defining type: {:?} with generator substs {:#?}",
+                    def_id,
+                    &substs.substs[..]
+                ));
+
+                let closure_base_def_id = tcx.closure_base_def_id(def_id);
+                for_each_late_bound_region_defined_on(tcx, closure_base_def_id, |r| {
+                    err.note(&format!(
+                        "late-bound region {:?} is {:?}",
+                        r,
+                        self.to_region_vid(r),
+                    ));
+                });
+            }
+            DefiningTy::FnDef(def_id, substs) => {
+                err.note(&format!(
+                    "defining type: {:?} with substs {:#?}",
+                    def_id,
+                    &substs[..]
+                ));
+            }
+            DefiningTy::Const(def_id, substs) => {
+                err.note(&format!(
+                    "defining constant type: {:?} with substs {:#?}",
+                    def_id,
+                    &substs[..]
+                ));
+            }
+        }
+    }
 }
 
 struct UniversalRegionsBuilder<'cx, 'gcx: 'tcx, 'tcx: 'cx> {

src/test/ui/nll/closure-requirements/propagate-approximated-fail-no-postdom.stderr

@@ -12,6 +12,9 @@ LL | |         },
                i16,
                for<'r, 's> extern "rust-call" fn((std::cell::Cell<&'_#1r &ReLateBound(DebruijnIndex(0), BrNamed(crate0:DefIndex(0:0), 'r)) u32>, std::cell::Cell<&'_#2r &ReLateBound(DebruijnIndex(0), BrNamed(crate0:DefIndex(0:0), 'r)) u32>, std::cell::Cell<&ReLateBound(DebruijnIndex(0), BrNamed(crate0:DefIndex(0:0), 's)) &'_#3r u32>, std::cell::Cell<&ReLateBound(DebruijnIndex(0), BrNamed(crate0:DefIndex(0:0), 'r)) u32>, std::cell::Cell<&ReLateBound(DebruijnIndex(0), BrNamed(crate0:DefIndex(0:0), 's)) u32>))
            ]
+   = note: late-bound region ReFree(DefId(0/0:6 ~ propagate_approximated_fail_no_postdom[317d]::supply[0]), BrNamed(crate0:DefIndex(1:17), 'a)) is '_#4r
+   = note: late-bound region ReFree(DefId(0/0:6 ~ propagate_approximated_fail_no_postdom[317d]::supply[0]), BrNamed(crate0:DefIndex(1:19), 'c)) is '_#5r
+   = note: late-bound region ReFree(DefId(0/0:6 ~ propagate_approximated_fail_no_postdom[317d]::supply[0]), BrNamed(crate0:DefIndex(1:18), 'b)) is '_#6r
 
 error: unsatisfied lifetime constraints
   --> $DIR/propagate-approximated-fail-no-postdom.rs:56:13

src/test/ui/nll/closure-requirements/propagate-approximated-ref.stderr

@@ -14,6 +14,8 @@ LL | |     });
                i16,
                for<'r, 's, 't0, 't1, 't2, 't3> extern "rust-call" fn((&ReLateBound(DebruijnIndex(0), BrNamed(crate0:DefIndex(0:0), 'r)) std::cell::Cell<&'_#1r &ReLateBound(DebruijnIndex(0), BrNamed(crate0:DefIndex(0:0), 's)) u32>, &ReLateBound(DebruijnIndex(0), BrNamed(crate0:DefIndex(0:0), 't0)) std::cell::Cell<&ReLateBound(DebruijnIndex(0), BrNamed(crate0:DefIndex(0:0), 't1)) &'_#2r u32>, &ReLateBound(DebruijnIndex(0), BrNamed(crate0:DefIndex(0:0), 't2)) std::cell::Cell<&ReLateBound(DebruijnIndex(0), BrNamed(crate0:DefIndex(0:0), 's)) u32>, &ReLateBound(DebruijnIndex(0), BrNamed(crate0:DefIndex(0:0), 't3)) std::cell::Cell<&ReLateBound(DebruijnIndex(0), BrNamed(crate0:DefIndex(0:0), 't1)) u32>))
            ]
+   = note: late-bound region ReFree(DefId(0/0:6 ~ propagate_approximated_ref[317d]::supply[0]), BrNamed(crate0:DefIndex(1:17), 'b)) is '_#3r
+   = note: late-bound region ReFree(DefId(0/0:6 ~ propagate_approximated_ref[317d]::supply[0]), BrNamed(crate0:DefIndex(1:16), 'a)) is '_#4r
    = note: number of external vids: 5
    = note: where '_#1r: '_#2r
 

src/test/ui/nll/closure-requirements/propagate-approximated-shorter-to-static-no-bound.stderr

@@ -15,6 +15,8 @@ LL | |     });
                i16,
                for<'r, 's, 't0, 't1, 't2> extern "rust-call" fn((&ReLateBound(DebruijnIndex(0), BrNamed(crate0:DefIndex(0:0), 'r)) std::cell::Cell<&'_#1r &ReLateBound(DebruijnIndex(0), BrNamed(crate0:DefIndex(0:0), 's)) u32>, &ReLateBound(DebruijnIndex(0), BrNamed(crate0:DefIndex(0:0), 't0)) std::cell::Cell<&ReLateBound(DebruijnIndex(0), BrNamed(crate0:DefIndex(0:0), 's)) u32>, &ReLateBound(DebruijnIndex(0), BrNamed(crate0:DefIndex(0:0), 't1)) std::cell::Cell<&ReLateBound(DebruijnIndex(0), BrNamed(crate0:DefIndex(0:0), 't2)) u32>))
            ]
+   = note: late-bound region ReFree(DefId(0/0:6 ~ propagate_approximated_shorter_to_static_no_bound[317d]::supply[0]), BrNamed(crate0:DefIndex(1:16), 'a)) is '_#2r
+   = note: late-bound region ReFree(DefId(0/0:6 ~ propagate_approximated_shorter_to_static_no_bound[317d]::supply[0]), BrNamed(crate0:DefIndex(1:17), 'b)) is '_#3r
    = note: number of external vids: 4
    = note: where '_#1r: '_#0r
 

src/test/ui/nll/closure-requirements/propagate-approximated-shorter-to-static-wrong-bound.stderr

@@ -14,6 +14,8 @@ LL | |     });
                i16,
                for<'r, 's, 't0, 't1, 't2, 't3> extern "rust-call" fn((&ReLateBound(DebruijnIndex(0), BrNamed(crate0:DefIndex(0:0), 'r)) std::cell::Cell<&'_#1r &ReLateBound(DebruijnIndex(0), BrNamed(crate0:DefIndex(0:0), 's)) u32>, &ReLateBound(DebruijnIndex(0), BrNamed(crate0:DefIndex(0:0), 't0)) std::cell::Cell<&'_#2r &ReLateBound(DebruijnIndex(0), BrNamed(crate0:DefIndex(0:0), 't1)) u32>, &ReLateBound(DebruijnIndex(0), BrNamed(crate0:DefIndex(0:0), 't2)) std::cell::Cell<&ReLateBound(DebruijnIndex(0), BrNamed(crate0:DefIndex(0:0), 's)) u32>, &ReLateBound(DebruijnIndex(0), BrNamed(crate0:DefIndex(0:0), 't3)) std::cell::Cell<&ReLateBound(DebruijnIndex(0), BrNamed(crate0:DefIndex(0:0), 't1)) u32>))
            ]
+   = note: late-bound region ReFree(DefId(0/0:6 ~ propagate_approximated_shorter_to_static_wrong_bound[317d]::supply[0]), BrNamed(crate0:DefIndex(1:17), 'b)) is '_#3r
+   = note: late-bound region ReFree(DefId(0/0:6 ~ propagate_approximated_shorter_to_static_wrong_bound[317d]::supply[0]), BrNamed(crate0:DefIndex(1:16), 'a)) is '_#4r
    = note: number of external vids: 5
    = note: where '_#1r: '_#0r
 

src/test/ui/nll/closure-requirements/propagate-approximated-val.stderr

@@ -14,6 +14,8 @@ LL | |     });
                i16,
                for<'r, 's> extern "rust-call" fn((std::cell::Cell<&'_#1r &ReLateBound(DebruijnIndex(0), BrNamed(crate0:DefIndex(0:0), 'r)) u32>, std::cell::Cell<&ReLateBound(DebruijnIndex(0), BrNamed(crate0:DefIndex(0:0), 's)) &'_#2r u32>, std::cell::Cell<&ReLateBound(DebruijnIndex(0), BrNamed(crate0:DefIndex(0:0), 'r)) u32>, std::cell::Cell<&ReLateBound(DebruijnIndex(0), BrNamed(crate0:DefIndex(0:0), 's)) u32>))
            ]
+   = note: late-bound region ReFree(DefId(0/0:6 ~ propagate_approximated_val[317d]::test[0]), BrNamed(crate0:DefIndex(1:17), 'b)) is '_#3r
+   = note: late-bound region ReFree(DefId(0/0:6 ~ propagate_approximated_val[317d]::test[0]), BrNamed(crate0:DefIndex(1:16), 'a)) is '_#4r
    = note: number of external vids: 5
    = note: where '_#1r: '_#2r
 

src/test/ui/nll/closure-requirements/propagate-despite-same-free-region.stderr

@@ -12,6 +12,7 @@ LL | |         },
                i16,
                for<'r, 's> extern "rust-call" fn((std::cell::Cell<&'_#1r &ReLateBound(DebruijnIndex(0), BrNamed(crate0:DefIndex(0:0), 'r)) u32>, std::cell::Cell<&ReLateBound(DebruijnIndex(0), BrNamed(crate0:DefIndex(0:0), 's)) &'_#2r u32>, std::cell::Cell<&ReLateBound(DebruijnIndex(0), BrNamed(crate0:DefIndex(0:0), 'r)) u32>, std::cell::Cell<&ReLateBound(DebruijnIndex(0), BrNamed(crate0:DefIndex(0:0), 's)) u32>))
            ]
+   = note: late-bound region ReFree(DefId(0/0:6 ~ propagate_despite_same_free_region[317d]::supply[0]), BrNamed(crate0:DefIndex(1:15), 'a)) is '_#3r
    = note: number of external vids: 4
    = note: where '_#1r: '_#2r
 

src/test/ui/nll/closure-requirements/propagate-fail-to-approximate-longer-no-bounds.stderr

@@ -13,6 +13,8 @@ LL | |     });
                i16,
                for<'r, 's, 't0, 't1, 't2> extern "rust-call" fn((&ReLateBound(DebruijnIndex(0), BrNamed(crate0:DefIndex(0:0), 'r)) std::cell::Cell<&ReLateBound(DebruijnIndex(0), BrNamed(crate0:DefIndex(0:0), 's)) &'_#1r u32>, &ReLateBound(DebruijnIndex(0), BrNamed(crate0:DefIndex(0:0), 't0)) std::cell::Cell<&ReLateBound(DebruijnIndex(0), BrNamed(crate0:DefIndex(0:0), 't1)) u32>, &ReLateBound(DebruijnIndex(0), BrNamed(crate0:DefIndex(0:0), 't2)) std::cell::Cell<&ReLateBound(DebruijnIndex(0), BrNamed(crate0:DefIndex(0:0), 's)) u32>))
            ]
+   = note: late-bound region ReFree(DefId(0/0:6 ~ propagate_fail_to_approximate_longer_no_bounds[317d]::supply[0]), BrNamed(crate0:DefIndex(1:16), 'a)) is '_#2r
+   = note: late-bound region ReFree(DefId(0/0:6 ~ propagate_fail_to_approximate_longer_no_bounds[317d]::supply[0]), BrNamed(crate0:DefIndex(1:17), 'b)) is '_#3r
 
 error: unsatisfied lifetime constraints
   --> $DIR/propagate-fail-to-approximate-longer-no-bounds.rs:47:9

src/test/ui/nll/closure-requirements/propagate-fail-to-approximate-longer-wrong-bounds.stderr

@@ -13,6 +13,8 @@ LL | |     });
                i16,
                for<'r, 's, 't0, 't1, 't2, 't3> extern "rust-call" fn((&ReLateBound(DebruijnIndex(0), BrNamed(crate0:DefIndex(0:0), 'r)) std::cell::Cell<&ReLateBound(DebruijnIndex(0), BrNamed(crate0:DefIndex(0:0), 's)) &'_#1r u32>, &ReLateBound(DebruijnIndex(0), BrNamed(crate0:DefIndex(0:0), 't0)) std::cell::Cell<&ReLateBound(DebruijnIndex(0), BrNamed(crate0:DefIndex(0:0), 't1)) &'_#2r u32>, &ReLateBound(DebruijnIndex(0), BrNamed(crate0:DefIndex(0:0), 't2)) std::cell::Cell<&ReLateBound(DebruijnIndex(0), BrNamed(crate0:DefIndex(0:0), 's)) u32>, &ReLateBound(DebruijnIndex(0), BrNamed(crate0:DefIndex(0:0), 't3)) std::cell::Cell<&ReLateBound(DebruijnIndex(0), BrNamed(crate0:DefIndex(0:0), 't1)) u32>))
            ]
+   = note: late-bound region ReFree(DefId(0/0:6 ~ propagate_fail_to_approximate_longer_wrong_bounds[317d]::supply[0]), BrNamed(crate0:DefIndex(1:17), 'b)) is '_#3r
+   = note: late-bound region ReFree(DefId(0/0:6 ~ propagate_fail_to_approximate_longer_wrong_bounds[317d]::supply[0]), BrNamed(crate0:DefIndex(1:16), 'a)) is '_#4r
 
 error: unsatisfied lifetime constraints
   --> $DIR/propagate-fail-to-approximate-longer-wrong-bounds.rs:51:9

src/test/ui/nll/ty-outlives/projection-one-region-trait-bound-static-closure.stderr

@@ -10,6 +10,8 @@ LL |     with_signature(cell, t, |cell, t| require(cell, t));
                i32,
                extern "rust-call" fn((std::cell::Cell<&'_#2r ()>, T))
            ]
+   = note: late-bound region ReFree(DefId(0/0:8 ~ projection_one_region_trait_bound_static_closure[317d]::no_relationships_late[0]), BrNamed(crate0:DefIndex(1:16), 'a)) is '_#3r
+   = note: late-bound region ReFree(DefId(0/0:8 ~ projection_one_region_trait_bound_static_closure[317d]::no_relationships_late[0]), BrNamed(crate0:DefIndex(1:18), T)) is '_#4r
 
 note: No external requirements
   --> $DIR/projection-one-region-trait-bound-static-closure.rs:42:1
@@ -40,6 +42,7 @@ LL |     with_signature(cell, t, |cell, t| require(cell, t));
                i32,
                extern "rust-call" fn((std::cell::Cell<&'_#3r ()>, T))
            ]
+   = note: late-bound region ReFree(DefId(0/0:9 ~ projection_one_region_trait_bound_static_closure[317d]::no_relationships_early[0]), BrNamed(crate0:DefIndex(1:22), T)) is '_#4r
 
 note: No external requirements
   --> $DIR/projection-one-region-trait-bound-static-closure.rs:50:1
@@ -72,6 +75,7 @@ LL |     with_signature(cell, t, |cell, t| require(cell, t));
                i32,
                extern "rust-call" fn((std::cell::Cell<&'_#3r ()>, T))
            ]
+   = note: late-bound region ReFree(DefId(0/0:10 ~ projection_one_region_trait_bound_static_closure[317d]::projection_outlives[0]), BrNamed(crate0:DefIndex(1:26), T)) is '_#4r
 
 note: No external requirements
   --> $DIR/projection-one-region-trait-bound-static-closure.rs:59:1
@@ -104,6 +108,7 @@ LL |     with_signature(cell, t, |cell, t| require(cell, t));
                i32,
                extern "rust-call" fn((std::cell::Cell<&'_#3r ()>, T))
            ]
+   = note: late-bound region ReFree(DefId(0/0:11 ~ projection_one_region_trait_bound_static_closure[317d]::elements_outlive[0]), BrNamed(crate0:DefIndex(1:30), T)) is '_#4r
 
 note: No external requirements
   --> $DIR/projection-one-region-trait-bound-static-closure.rs:78:1
@@ -135,6 +140,7 @@ LL |     with_signature(cell, t, |cell, t| require(cell, t));
                i32,
                extern "rust-call" fn((std::cell::Cell<&'_#2r ()>, T))
            ]
+   = note: late-bound region ReFree(DefId(0/0:12 ~ projection_one_region_trait_bound_static_closure[317d]::one_region[0]), BrNamed(crate0:DefIndex(1:33), T)) is '_#3r
 
 note: No external requirements
   --> $DIR/projection-one-region-trait-bound-static-closure.rs:87:1