From e912c8dfe0f74f41c9b3dae1a4e1900f3dd9d0e6 Mon Sep 17 00:00:00 2001
From: Camille GILLOT <gillot.camille@gmail.com>
Date: Tue, 3 May 2022 22:04:49 +0200
Subject: Use a dedicated DepKind for the forever-red node.

---
 compiler/rustc_query_system/src/dep_graph/graph.rs | 10 ++++------
 compiler/rustc_query_system/src/dep_graph/mod.rs   |  4 ++++
 2 files changed, 8 insertions(+), 6 deletions(-)

(limited to 'compiler/rustc_query_system/src')

diff --git a/compiler/rustc_query_system/src/dep_graph/graph.rs b/compiler/rustc_query_system/src/dep_graph/graph.rs
index d218e3b7753..a1df192cc45 100644
--- a/compiler/rustc_query_system/src/dep_graph/graph.rs
+++ b/compiler/rustc_query_system/src/dep_graph/graph.rs
@@ -134,19 +134,19 @@ impl<K: DepKind> DepGraph<K> {
             smallvec![],
             Fingerprint::ZERO,
         );
-        debug_assert_eq!(_green_node_index, DepNodeIndex::SINGLETON_DEPENDENCYLESS_ANON_NODE);
+        assert_eq!(_green_node_index, DepNodeIndex::SINGLETON_DEPENDENCYLESS_ANON_NODE);
 
         // Instantiate a dependy-less red node only once for anonymous queries.
         let (_red_node_index, _prev_and_index) = current.intern_node(
             profiler,
             &prev_graph,
-            DepNode { kind: DepKind::NULL, hash: Fingerprint::ZERO.into() },
+            DepNode { kind: DepKind::RED, hash: Fingerprint::ZERO.into() },
             smallvec![],
             None,
             false,
         );
-        debug_assert_eq!(_red_node_index, DepNodeIndex::FOREVER_RED_NODE);
-        debug_assert!(matches!(_prev_and_index, None | Some((_, DepNodeColor::Red))));
+        assert_eq!(_red_node_index, DepNodeIndex::FOREVER_RED_NODE);
+        assert!(matches!(_prev_and_index, None | Some((_, DepNodeColor::Red))));
 
         DepGraph {
             data: Some(Lrc::new(DepGraphData {
@@ -981,8 +981,6 @@ impl<K: DepKind> CurrentDepGraph<K> {
         let mut stable_hasher = StableHasher::new();
         nanos.hash(&mut stable_hasher);
         let anon_id_seed = stable_hasher.finish();
-        // We rely on the fact that `anon_id_seed` is not zero when creating static nodes.
-        debug_assert_ne!(anon_id_seed, Fingerprint::ZERO);
 
         #[cfg(debug_assertions)]
         let forbidden_edge = match env::var("RUST_FORBID_DEP_GRAPH_EDGE") {
diff --git a/compiler/rustc_query_system/src/dep_graph/mod.rs b/compiler/rustc_query_system/src/dep_graph/mod.rs
index 345ada263e4..342d95ca490 100644
--- a/compiler/rustc_query_system/src/dep_graph/mod.rs
+++ b/compiler/rustc_query_system/src/dep_graph/mod.rs
@@ -85,8 +85,12 @@ impl FingerprintStyle {
 
 /// Describe the different families of dependency nodes.
 pub trait DepKind: Copy + fmt::Debug + Eq + Hash + Send + Encodable<FileEncoder> + 'static {
+    /// DepKind to use when incr. comp. is turned off.
     const NULL: Self;
 
+    /// DepKind to use to create the initial forever-red node.
+    const RED: Self;
+
     /// Implementation of `std::fmt::Debug` for `DepNode`.
     fn debug_node(node: &DepNode<Self>, f: &mut fmt::Formatter<'_>) -> fmt::Result;
 
-- 
cgit 1.4.1-3-g733a5