Auto merge of #61492 - RalfJung:const-qualif-comments, r=eddyb

[rust.git] / src / librustc / hir / map / definitions.rs

diff --git a/src/librustc/hir/map/definitions.rs b/src/librustc/hir/map/definitions.rs
index 2324c3f04284ff33483b490f92280ebc07a1afc8..6a561f0c63a2afa556eb4563bbd33f7c414e7a7c 100644 (file)
--- a/src/librustc/hir/map/definitions.rs
+++ b/src/librustc/hir/map/definitions.rs
@@ -239,7 +239,7 @@ pub fn to_string_friendly<F>(&self, crate_imported_name: F) -> String
                        "{}[{}]",
                        component.data.as_interned_str(),
                        component.disambiguator)
-                    .unwrap();
+                       .unwrap();
             }
         }
 
@@ -263,7 +263,7 @@ pub fn to_filename_friendly_no_crate(&self) -> String {
                        "{}[{}]",
                        component.data.as_interned_str(),
                        component.disambiguator)
-                    .unwrap();
+                       .unwrap();
             }
         }
         s
@@ -276,7 +276,7 @@ pub enum DefPathData {
     // they are treated specially by the `def_path` function.
     /// The crate root (marker)
     CrateRoot,
-    // Catch-all for random DefId things like DUMMY_NODE_ID
+    // Catch-all for random DefId things like `DUMMY_NODE_ID`
     Misc,
     // Different kinds of items and item-like things:
     /// An impl
@@ -298,9 +298,9 @@ pub enum DefPathData {
     AnonConst,
     /// An `impl Trait` type node
     ImplTrait,
-    /// GlobalMetaData identifies a piece of crate metadata that is global to
-    /// a whole crate (as opposed to just one item). GlobalMetaData components
-    /// are only supposed to show up right below the crate root.
+    /// Identifies a piece of crate metadata that is global to a whole crate
+    /// (as opposed to just one item). `GlobalMetaData` components are only
+    /// supposed to show up right below the crate root.
     GlobalMetaData(InternedString),
 }
 
@@ -397,6 +397,11 @@ pub fn def_index_to_hir_id(&self, def_index: DefIndex) -> hir::HirId {
         self.node_to_hir_id[node_id]
     }
 
+    #[inline]
+    pub fn def_index_to_node_id(&self, def_index: DefIndex) -> ast::NodeId {
+        self.as_local_node_id(DefId::local(def_index)).unwrap()
+    }
+
     /// Retrieves the span of the given `DefId` if `DefId` is in the local crate, the span exists
     /// and it's not `DUMMY_SP`.
     #[inline]
@@ -442,7 +447,7 @@ pub fn create_root_def(&mut self,
         root_index
     }
 
-    /// Add a definition with a parent definition.
+    /// Adds a definition with a parent definition.
     pub fn create_def_with_parent(&mut self,
                                   parent: DefIndex,
                                   node_id: ast::NodeId,
@@ -559,7 +564,7 @@ pub fn as_interned_str(&self) -> InternedString {
             GlobalMetaData(name) => {
                 return name
             }
-            // note that this does not show up in user printouts
+            // Note that this does not show up in user print-outs.
             CrateRoot => sym::double_braced_crate,
             Impl => sym::double_braced_impl,
             Misc => sym::double_braced_misc,
@@ -577,9 +582,17 @@ pub fn to_string(&self) -> String {
     }
 }
 
+/// Evaluates to the number of tokens passed to it.
+///
+/// Logarithmic counting: every one or two recursive expansions, the number of
+/// tokens to count is divided by two, instead of being reduced by one.
+/// Therefore, the recursion depth is the binary logarithm of the number of
+/// tokens to count, and the expanded tree is likewise very small.
 macro_rules! count {
-    () => (0usize);
-    ( $x:tt $($xs:tt)* ) => (1usize + count!($($xs)*));
+    ()                     => (0usize);
+    ($one:tt)              => (1usize);
+    ($($pairs:tt $_p:tt)*) => (count!($($pairs)*) << 1usize);
+    ($odd:tt $($rest:tt)*) => (count!($($rest)*) | 1usize);
 }
 
 // We define the GlobalMetaDataKind enum with this macro because we want to