From 07df8125e6a32796a14ac253aa0df2a0847098b6 Mon Sep 17 00:00:00 2001
From: Niko Matsakis <niko@alum.mit.edu>
Date: Fri, 2 Sep 2016 11:55:32 -0400
Subject: [PATCH] kill the forbidden code

supplanted by RUST_FORBID_DEP_GRAPH_EDGE
---
 src/librustc/dep_graph/graph.rs | 16 ----------------
 src/librustc/dep_graph/raii.rs  | 16 ----------------
 2 files changed, 32 deletions(-)

diff --git a/src/librustc/dep_graph/graph.rs b/src/librustc/dep_graph/graph.rs
index ca441c4bc3ff..c42eeead69ec 100644
--- a/src/librustc/dep_graph/graph.rs
+++ b/src/librustc/dep_graph/graph.rs
@@ -38,10 +38,6 @@ struct DepGraphData {
 
     /// Work-products that we generate in this run.
     work_products: RefCell<FnvHashMap<Arc<WorkProductId>, WorkProduct>>,
-
-    /// Tracks nodes that are forbidden to read/write; see
-    /// `DepGraph::forbid`. Used for debugging only.
-    forbidden: RefCell<Vec<DepNode<DefId>>>,
 }
 
 impl DepGraph {
@@ -51,7 +47,6 @@ impl DepGraph {
                 thread: DepGraphThreadData::new(enabled),
                 previous_work_products: RefCell::new(FnvHashMap()),
                 work_products: RefCell::new(FnvHashMap()),
-                forbidden: RefCell::new(Vec::new()),
             })
         }
     }
@@ -75,15 +70,6 @@ impl DepGraph {
         raii::DepTask::new(&self.data.thread, key)
     }
 
-    /// Debugging aid -- forbid reads/writes to `key` while the return
-    /// value is in scope. Note that this is only available when debug
-    /// assertions are enabled -- you should not check in code that
-    /// invokes this function.
-    #[cfg(debug_assertions)]
-    pub fn forbid<'graph>(&'graph self, key: DepNode<DefId>) -> raii::Forbid<'graph> {
-        raii::Forbid::new(&self.data.forbidden, key)
-    }
-
     pub fn with_ignore<OP,R>(&self, op: OP) -> R
         where OP: FnOnce() -> R
     {
@@ -99,12 +85,10 @@ impl DepGraph {
     }
 
     pub fn read(&self, v: DepNode<DefId>) {
-        debug_assert!(!self.data.forbidden.borrow().contains(&v));
         self.data.thread.enqueue(DepMessage::Read(v));
     }
 
     pub fn write(&self, v: DepNode<DefId>) {
-        debug_assert!(!self.data.forbidden.borrow().contains(&v));
         self.data.thread.enqueue(DepMessage::Write(v));
     }
 
diff --git a/src/librustc/dep_graph/raii.rs b/src/librustc/dep_graph/raii.rs
index b344eb486240..4445a02785b5 100644
--- a/src/librustc/dep_graph/raii.rs
+++ b/src/librustc/dep_graph/raii.rs
@@ -49,19 +49,3 @@ impl<'graph> Drop for IgnoreTask<'graph> {
     }
 }
 
-pub struct Forbid<'graph> {
-    forbidden: &'graph RefCell<Vec<DepNode<DefId>>>
-}
-
-impl<'graph> Forbid<'graph> {
-    pub fn new(forbidden: &'graph RefCell<Vec<DepNode<DefId>>>, node: DepNode<DefId>) -> Self {
-        forbidden.borrow_mut().push(node);
-        Forbid { forbidden: forbidden }
-    }
-}
-
-impl<'graph> Drop for Forbid<'graph> {
-    fn drop(&mut self) {
-        self.forbidden.borrow_mut().pop();
-    }
-}