1 files changed, 66 insertions, 0 deletions
diff --git a/build/scope.cxx b/build/scope.cxx
index 0f99b0e..7165663 100644
--- a/build/scope.cxx
+++ b/build/scope.cxx
@@ -9,4 +9,70 @@ using namespace std;
 namespace build
 {
   scope_map scopes;
+  scope* root_scope;
+
+  scope& scope_map::
+  operator[] (const path& k)
+  {
+    auto er (emplace (k, scope ()));
+    scope& s (er.first->second);
+
+    if (er.second)
+    {
+      scope* p (nullptr);
+
+      // Update scopes of which we are a new parent.
+      //
+      for (auto r (find_prefix (k)); r.first != r.second; ++r.first)
+      {
+        scope& c (r.first->second);
+
+        // The first scope of which we are a parent is the least
+        // (shortest) one which means there is no other scope
+        // between it and our parent.
+        //
+        if (p == nullptr)
+          p = &c;
+        else if (p != &c) // A scope with an intermediate parent.
+          continue;
+
+        c.parent (s);
+      }
+
+      // We couldn't get the parent from one of its old children
+      // so we have to find it ourselves (unless this is is the
+      // root scope).
+      //
+      if (p == nullptr && size () != 1)
+        p = &find (k);
+
+      s.init (er.first, p);
+    }
+
+    return s;
+  }
+
+  // Find the most qualified scope that encompasses this path.
+  //
+  scope& scope_map::
+  find (const path& k)
+  {
+    // Normally we would have a scope for the full path so try
+    // that before making any copies.
+    //
+    auto i (base::find (k));
+
+    if (i != end ())
+      return i->second;
+
+    for (path d (k.directory ());; d = d.directory ())
+    {
+      auto i (base::find (k));
+
+      if (i != end ())
+        return i->second;
+
+      assert (d.empty ()); // We should have the root scope.
+    }
+  }
 }