From ec23e3f4b8307d14443ddf9a70f2acb5c519c486 Mon Sep 17 00:00:00 2001
From: Taylor Cramer <cramertaylorj@gmail.com>
Date: Mon, 10 Apr 2017 23:51:35 -0700
Subject: [PATCH] Convert fn_id to outermost in region_maps

---
 src/librustc/hir/map/mod.rs   | 12 ++++++++++++
 src/librustc/middle/region.rs | 27 +++++++++++++++++++++------
 src/librustc/ty/context.rs    | 15 +++++++++++++--
 3 files changed, 46 insertions(+), 8 deletions(-)

diff --git a/src/librustc/hir/map/mod.rs b/src/librustc/hir/map/mod.rs
index 48b8a819fff03..cae5c5011ce7e 100644
--- a/src/librustc/hir/map/mod.rs
+++ b/src/librustc/hir/map/mod.rs
@@ -572,6 +572,18 @@ impl<'hir> Map<'hir> {
         }
     }
 
+    /// Check if the node is a non-closure function item
+    pub fn is_fn(&self, id: NodeId) -> bool {
+        let entry = if let Some(id) = self.find_entry(id) { id } else { return false };
+
+        match entry {
+            EntryItem(_, &Item { node: ItemFn(..), .. }) |
+            EntryTraitItem(_, &TraitItem { node: TraitItemKind::Method(..), .. }) |
+            EntryImplItem(_, &ImplItem { node: ImplItemKind::Method(..), .. }) => true,
+            _ => false,
+        }
+    }
+
     /// If there is some error when walking the parents (e.g., a node does not
     /// have a parent in the map or a node can't be found), then we return the
     /// last good node id we found. Note that reaching the crate root (id == 0),
diff --git a/src/librustc/middle/region.rs b/src/librustc/middle/region.rs
index 19e6aafd6b222..81e99e52ffbdd 100644
--- a/src/librustc/middle/region.rs
+++ b/src/librustc/middle/region.rs
@@ -348,7 +348,7 @@ struct RegionResolutionVisitor<'hir: 'a, 'a> {
     /// destructor's execution.
     terminating_scopes: NodeSet,
 
-    target_fn_id: DefId,
+    target_fn_node_id: NodeId,
 
     found_target_fn: bool,
 }
@@ -1142,11 +1142,10 @@ fn resolve_fn<'a, 'tcx>(visitor: &mut RegionResolutionVisitor<'tcx, 'a>,
                         body_id: hir::BodyId,
                         sp: Span,
                         id: ast::NodeId) {
-
     visitor.cx.parent = visitor.new_code_extent(
         CodeExtentData::CallSiteScope { fn_id: id, body_id: body_id.node_id });
 
-    if body_id == visitor.target_fn_id {
+    if id == visitor.target_fn_node_id {
         // We've found the top level `fn`. Store it and its children in the `RegionMaps`
         visitor.found_target_fn = true;
     }
@@ -1270,8 +1269,23 @@ impl<'hir, 'a> Visitor<'hir> for RegionResolutionVisitor<'hir, 'a> {
     }
 }
 
-pub fn resolve_crate<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>) -> Rc<RegionMaps> {
-    ty::queries::region_resolve_fn::get(tcx, DUMMY_SP, LOCAL_CRATE)
+pub fn resolve_crate<'a, 'tcx: 'a>(tcx: TyCtxt<'a, 'tcx, 'tcx>) {
+
+    struct CrateResolutionVisitor<'a, 'tcx: 'a>(TyCtxt<'a, 'tcx, 'tcx>);
+
+    impl<'a, 'hir: 'a> Visitor<'hir> for CrateResolutionVisitor<'a, 'hir> {
+        fn nested_visit_map<'this>(&'this mut self) -> NestedVisitorMap<'this, 'hir> {
+            NestedVisitorMap::OnlyBodies(&self.0.hir)
+        }
+        fn visit_fn(&mut self, _fk: FnKind<'hir>, _fd: &'hir FnDecl,
+                    _b: hir::BodyId, _s: Span, fn_id: NodeId)
+        {
+            let fn_def_id = self.0.hir.local_def_id(fn_id);
+            ty::queries::region_resolve_fn::get(self.0, DUMMY_SP, fn_def_id);
+        }
+    }
+
+    tcx.hir.krate().visit_all_item_likes(&mut CrateResolutionVisitor(tcx).as_deep_visitor());
 }
 
 fn region_resolve_fn<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>, fn_id: DefId)
@@ -1308,7 +1322,8 @@ fn region_resolve_fn<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>, fn_id: DefId)
                 var_parent: ROOT_CODE_EXTENT
             },
             terminating_scopes: NodeSet(),
-            target_fn_id: fn_id,
+            target_fn_node_id: hir_map.as_local_node_id(fn_id)
+                                      .expect("fn DefId should be for LOCAL_CRATE"),
             found_target_fn: false,
         };
         krate.visit_all_item_likes(&mut visitor.as_deep_visitor());
diff --git a/src/librustc/ty/context.rs b/src/librustc/ty/context.rs
index 97cfa9c9de945..a33a788221815 100644
--- a/src/librustc/ty/context.rs
+++ b/src/librustc/ty/context.rs
@@ -663,8 +663,19 @@ impl<'a, 'gcx, 'tcx> TyCtxt<'a, 'gcx, 'tcx> {
         local as usize == global as usize
     }
 
-    pub fn region_maps(self) -> Rc<RegionMaps> {
-        ty::queries::region_resolve_crate::get(self, DUMMY_SP, LOCAL_CRATE)
+    pub fn region_maps(self, fn_id: NodeId) -> Rc<RegionMaps> {
+        // Find the `NodeId` of the outermost function that wraps the function pointed to by fn_id
+        let mut outermost_fn_id = fn_id;
+        let mut outermost_id = fn_id;
+        loop {
+            let next_id = self.hir.get_parent(outermost_id);
+            if outermost_id == next_id { break; }
+            if self.hir.is_fn(outermost_id) {
+                outermost_fn_id = outermost_id;
+            }
+        }
+
+        ty::queries::region_resolve_fn::get(self, DUMMY_SP, self.hir.local_def_id(outermost_fn_id))
     }
 
     /// Create a type context and call the closure with a `TyCtxt` reference