Only retain external static symbols across LTO

[rust.git] / src / librustc / middle / privacy.rs

diff --git a/src/librustc/middle/privacy.rs b/src/librustc/middle/privacy.rs
index 3a253735f925b032e93390ce3618f6c4aa4aec87..f464ea58c2d196f76a103d5e493791b2dc9f6ec7 100644 (file)
--- a/src/librustc/middle/privacy.rs
+++ b/src/librustc/middle/privacy.rs
@@ -16,23 +16,56 @@
 pub use self::ImportUse::*;
 pub use self::LastPrivate::*;
 
-use util::nodemap::{DefIdSet, NodeSet};
+use middle::def_id::DefId;
+use util::nodemap::{DefIdSet, FnvHashMap};
 
-use syntax::ast;
+use std::hash::Hash;
+use syntax::ast::NodeId;
 
-/// A set of AST nodes exported by the crate.
-pub type ExportedItems = NodeSet;
+// Accessibility levels, sorted in ascending order
+#[derive(Clone, Copy, PartialEq, Eq, PartialOrd, Ord)]
+pub enum AccessLevel {
+    // Exported items + items participating in various kinds of public interfaces,
+    // but not directly nameable. For example, if function `fn f() -> T {...}` is
+    // public, then type `T` is exported. Its values can be obtained by other crates
+    // even if the type itseld is not nameable.
+    // FIXME: Mostly unimplemented. Only `type` aliases export items currently.
+    Reachable,
+    // Public items + items accessible to other crates with help of `pub use` reexports
+    Exported,
+    // Items accessible to other crates directly, without help of reexports
+    Public,
+}
+
+// Accessibility levels for reachable HIR nodes
+#[derive(Clone)]
+pub struct AccessLevels<Id = NodeId> {
+    pub map: FnvHashMap<Id, AccessLevel>
+}
+
+impl<Id: Hash + Eq> AccessLevels<Id> {
+    pub fn is_reachable(&self, id: Id) -> bool {
+        self.map.contains_key(&id)
+    }
+    pub fn is_exported(&self, id: Id) -> bool {
+        self.map.get(&id) >= Some(&AccessLevel::Exported)
+    }
+    pub fn is_public(&self, id: Id) -> bool {
+        self.map.get(&id) >= Some(&AccessLevel::Public)
+    }
+}
+
+impl<Id: Hash + Eq> Default for AccessLevels<Id> {
+    fn default() -> Self {
+        AccessLevels { map: Default::default() }
+    }
+}
 
 /// A set containing all exported definitions from external crates.
 /// The set does not contain any entries from local crates.
 pub type ExternalExports = DefIdSet;
 
-/// A set of AST nodes that are fully public in the crate. This map is used for
-/// documentation purposes (reexporting a private struct inlines the doc,
-/// reexporting a public struct doesn't inline the doc).
-pub type PublicItems = NodeSet;
-
-#[derive(Copy, Debug)]
+#[derive(Copy, Clone, Debug)]
 pub enum LastPrivate {
     LastMod(PrivateDep),
     // `use` directives (imports) can refer to two separate definitions in the
@@ -46,14 +79,14 @@ pub enum LastPrivate {
                type_used: ImportUse},
 }
 
-#[derive(Copy, Debug)]
+#[derive(Copy, Clone, Debug)]
 pub enum PrivateDep {
     AllPublic,
-    DependsOn(ast::DefId),
+    DependsOn(DefId),
 }
 
 // How an import is used.
-#[derive(Copy, PartialEq, Debug)]
+#[derive(Copy, Clone, PartialEq, Debug)]
 pub enum ImportUse {
     Unused,       // The import is not used.
     Used,         // The import is used.