From 29c3e3b8912b784d9e2e4a4bec4c2378c7ffef7a Mon Sep 17 00:00:00 2001
From: Boris Kolpackov <boris@codesynthesis.com>
Date: Wed, 8 Apr 2015 11:29:43 +0200
Subject: Get rid of need to store scope in variable value

---
 build/cxx/module.cxx | 10 +++++-----
 build/parser.cxx     |  8 ++++----
 build/variable       | 34 ++++++++--------------------------
 build/variable.ixx   |  7 +++----
 4 files changed, 20 insertions(+), 39 deletions(-)

diff --git a/build/cxx/module.cxx b/build/cxx/module.cxx
index 04b1ae5..435e54c 100644
--- a/build/cxx/module.cxx
+++ b/build/cxx/module.cxx
@@ -49,7 +49,7 @@ namespace build
 
         if (val)
         {
-          if (&val.scope () != global_scope)
+          if (val.scope != global_scope)
             break; // A value from config.build.
 
           v = val.as<const string&> ();
@@ -110,7 +110,7 @@ namespace build
       //
       if (auto val = root["config.cxx.poptions"])
       {
-        if (&val.scope () == global_scope)
+        if (val.scope == global_scope)
           root.variables["config.cxx.poptions"] = val;
       }
       else
@@ -118,7 +118,7 @@ namespace build
 
       if (auto val = root["config.cxx.coptions"])
       {
-        if (&val.scope () == global_scope)
+        if (val.scope == global_scope)
           root.variables["config.cxx.coptions"] = val;
       }
       else
@@ -126,7 +126,7 @@ namespace build
 
       if (auto val = root["config.cxx.loptions"])
       {
-        if (&val.scope () == global_scope)
+        if (val.scope == global_scope)
           root.variables["config.cxx.loptions"] = val;
       }
       else
@@ -134,7 +134,7 @@ namespace build
 
       if (auto val = root["config.cxx.libs"])
       {
-        if (&val.scope () == global_scope)
+        if (val.scope == global_scope)
           root.variables["config.cxx.libs"] = val;
       }
       else
diff --git a/build/parser.cxx b/build/parser.cxx
index 2845143..24a1e98 100644
--- a/build/parser.cxx
+++ b/build/parser.cxx
@@ -700,7 +700,7 @@ namespace build
 
       if (val == nullptr) // Initialization.
       {
-        val.reset (new list_value (*scope_, move (vns)));
+        val.reset (new list_value (move (vns)));
       }
       else // Assignment.
       {
@@ -717,9 +717,9 @@ namespace build
         //
         list_value* lv (&val.as<list_value&> ());
 
-        if (&lv->scope != scope_) // Append to value from parent scope?
+        if (val.scope != scope_) // Append to value from parent scope?
         {
-          list_value_ptr nval (new list_value (*scope_, lv->data));
+          list_value_ptr nval (new list_value (lv->data));
           lv = nval.get (); // Append to.
           scope_->variables.emplace (var, move (nval));
         }
@@ -730,7 +730,7 @@ namespace build
       }
       else // Initialization.
       {
-        list_value_ptr nval (new list_value (*scope_, move (vns)));
+        list_value_ptr nval (new list_value (move (vns)));
         scope_->variables.emplace (var, move (nval));
       }
     }
diff --git a/build/variable b/build/variable
index aca0bed..fc0ba2b 100644
--- a/build/variable
+++ b/build/variable
@@ -53,15 +53,9 @@ namespace build
 
   struct value
   {
-    typedef build::scope scope_type;
-
-    scope_type& scope; // Scope to which this value belongs.
-
   public:
-    value (scope_type& s): scope (s) {}
-
     virtual value_ptr
-    clone (scope_type& s) const = 0;
+    clone () const = 0;
 
     virtual bool
     compare (const value&) const = 0;
@@ -75,24 +69,15 @@ namespace build
     names data;
 
   public:
-    list_value (scope_type& s, names d): value (s), data (std::move (d)) {}
-
-    list_value (scope_type& s, std::string d)
-        : value (s)
-    {
-      data.emplace_back (std::move (d));
-    }
+    list_value (names d): data (std::move (d)) {}
+    list_value (std::string d) {data.emplace_back (std::move (d));}
 
     // Note: stored in name as a directory.
     //
-    list_value (scope_type& s, path d)
-        : value (s)
-    {
-      data.emplace_back (std::move (d));
-    }
+    list_value (path d) {data.emplace_back (std::move (d));}
 
     virtual value_ptr
-    clone (scope_type& s) const {return value_ptr (new list_value (s, data));}
+    clone () const {return value_ptr (new list_value (data));}
 
     virtual bool
     compare (const value& v) const
@@ -112,8 +97,7 @@ namespace build
     explicit operator bool () const {return p != nullptr && *p != nullptr;}
     explicit operator value_ptr& () const {return *p;}
 
-    scope_type&
-    scope () const {return *s;}
+    scope_type* scope;
 
     // Get interface. See available specializations below.
     //
@@ -139,12 +123,10 @@ namespace build
 
     // Implementation details.
     //
-    explicit
-    value_proxy (value_ptr* p, scope_type* s): p (p), s (s) {}
+    value_proxy (value_ptr* p, scope_type* s): p (p), scope (s) {}
 
-  protected:
+  private:
     value_ptr* p;
-    scope_type* s;
   };
 
   template <>
diff --git a/build/variable.ixx b/build/variable.ixx
index 85fdd50..ca5a24a 100644
--- a/build/variable.ixx
+++ b/build/variable.ixx
@@ -7,7 +7,6 @@ namespace build
   inline const value_proxy& value_proxy::
   operator= (value_ptr v) const
   {
-    assert (v == nullptr || &v->scope == s);
     *p = std::move (v);
     return *this;
   }
@@ -18,7 +17,7 @@ namespace build
     if (this != &v)
     {
       if (v)
-        *p = v.as<const value&> ().clone (*s);
+        *p = v.as<const value&> ().clone ();
       else
         p->reset ();
     }
@@ -33,14 +32,14 @@ namespace build
     // don't bother trying to optimize for the case where p is not
     // NULL.
     //
-    p->reset (new list_value (*s, std::move (v)));
+    p->reset (new list_value (std::move (v)));
     return *this;
   }
 
   inline const value_proxy& value_proxy::
   operator= (path v) const
   {
-    p->reset (new list_value (*s, std::move (v)));
+    p->reset (new list_value (std::move (v)));
     return *this;
   }
 }
-- 
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