From ffd53277dc776dcf93bfa34c478bd99da2361515 Mon Sep 17 00:00:00 2001
From: Aman Arora <me@aman-arora.com>
Date: Tue, 12 Jan 2021 14:54:12 -0500
Subject: [PATCH] Add fixme for precise path diagnostics

---
 compiler/rustc_mir/src/borrow_check/diagnostics/mod.rs |  2 ++
 compiler/rustc_mir/src/borrow_check/mod.rs             | 10 +++++-----
 2 files changed, 7 insertions(+), 5 deletions(-)

diff --git a/compiler/rustc_mir/src/borrow_check/diagnostics/mod.rs b/compiler/rustc_mir/src/borrow_check/diagnostics/mod.rs
index 6d98bf554f1c..04ea3cbd8b66 100644
--- a/compiler/rustc_mir/src/borrow_check/diagnostics/mod.rs
+++ b/compiler/rustc_mir/src/borrow_check/diagnostics/mod.rs
@@ -215,6 +215,7 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
             PlaceRef { local, projection: [proj_base @ .., elem] } => {
                 match elem {
                     ProjectionElem::Deref => {
+                        // FIXME(project-rfc_2229#36): print capture precisely here.
                         let upvar_field_projection = self.is_upvar_field_projection(place);
                         if let Some(field) = upvar_field_projection {
                             let var_index = field.index();
@@ -259,6 +260,7 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
                     ProjectionElem::Field(field, _ty) => {
                         autoderef = true;
 
+                        // FIXME(project-rfc_2229#36): print capture precisely here.
                         let upvar_field_projection = self.is_upvar_field_projection(place);
                         if let Some(field) = upvar_field_projection {
                             let var_index = field.index();
diff --git a/compiler/rustc_mir/src/borrow_check/mod.rs b/compiler/rustc_mir/src/borrow_check/mod.rs
index b51cba15d32a..c42e271f40e4 100644
--- a/compiler/rustc_mir/src/borrow_check/mod.rs
+++ b/compiler/rustc_mir/src/borrow_check/mod.rs
@@ -73,8 +73,7 @@ crate use region_infer::RegionInferenceContext;
 // FIXME(eddyb) perhaps move this somewhere more centrally.
 #[derive(Debug)]
 crate struct Upvar<'tcx> {
-    // FIXME(project-rfc-2229#8): ty::CapturePlace should have a to_string(), or similar
-    //                           then this should not be needed.
+    // FIXME(project-rfc_2229#36): print capture precisely here.
     name: Symbol,
 
     place: CapturedPlace<'tcx>,
@@ -2156,6 +2155,7 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
         place: PlaceRef<'tcx>,
         is_local_mutation_allowed: LocalMutationIsAllowed,
     ) -> Result<RootPlace<'tcx>, PlaceRef<'tcx>> {
+        debug!("is_mutable: place={:?}, is_local...={:?}", place, is_local_mutation_allowed);
         match place.last_projection() {
             None => {
                 let local = &self.body.local_decls[place.local];
@@ -2237,9 +2237,9 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
                         if let Some(field) = upvar_field_projection {
                             let upvar = &self.upvars[field.index()];
                             debug!(
-                                "upvar.mutability={:?} local_mutation_is_allowed={:?} \
-                                 place={:?}",
-                                upvar, is_local_mutation_allowed, place
+                                "is_mutable: upvar.mutability={:?} local_mutation_is_allowed={:?} \
+                                 place={:?}, place_base={:?}",
+                                upvar, is_local_mutation_allowed, place, place_base
                             );
                             match (upvar.place.mutability, is_local_mutation_allowed) {
                                 (