From 0342dc2fcdd78ef28a4e59d84193a3807068d726 Mon Sep 17 00:00:00 2001
From: Boris Kolpackov <boris@codesynthesis.com>
Date: Mon, 11 Apr 2016 07:57:19 +0200
Subject: New configuration logic, iteration 1

---
 build2/config/utility.txx | 40 ++++++++++++++++++++++++++++++++--------
 1 file changed, 32 insertions(+), 8 deletions(-)

(limited to 'build2/config/utility.txx')

diff --git a/build2/config/utility.txx b/build2/config/utility.txx
index d3c57a54..f49be75f 100644
--- a/build2/config/utility.txx
+++ b/build2/config/utility.txx
@@ -3,6 +3,7 @@
 // license   : MIT; see accompanying LICENSE file
 
 #include <build2/scope>
+#include <build2/context>
 
 namespace build2
 {
@@ -10,20 +11,43 @@ namespace build2
   {
     template <typename T>
     pair<reference_wrapper<const value>, bool>
-    required (scope& root, const variable& var, const T& def_value, bool ovr)
+    required (scope& root, const variable& var, const T& def_val, bool def_ovr)
     {
-      using result = pair<reference_wrapper<const value>, bool>;
+      if (current_mif->id == configure_id)
+        save_variable (root, var);
 
-      if (auto l = root[var])
+      pair<lookup, size_t> org (root.find_original (var));
+      lookup l (org.first);
+      bool n (false);
+
+      // The interaction with command line overrides can get tricky. For
+      // example, the override to defaul value could make (non-recursive)
+      // command line override in the outer scope no longer apply. So what we
+      // are going to do is first ignore overrides and perform the normal
+      // logic on the original. Then we apply the overrides on the result.
+      //
+      if (!l.defined () || (def_ovr && !l.belongs (root)))
       {
-        if (l.belongs (*global_scope))
-          return result (root.assign (var) = *l, true);
+        l = lookup ((root.assign (var) = def_val), root);
+        org = make_pair (l, 1); // Lookup depth is 1 since in root.vars.
+        n = true;
+      }
+
+      if (var.override != nullptr)
+      {
+        pair<lookup, size_t> ovr (root.find_override (var, move (org)));
+
+        if (l != ovr.first) // Overriden?
+        {
+          l = move (ovr.first);
 
-        if (!ovr || l.belongs (root))
-          return result (*l, false);
+          // Overriden and not inherited (same logic as in save_config()).
+          //
+          n = l.belongs (root) || l.belongs (*global_scope);
+        }
       }
 
-      return result (root.assign (var) = def_value, true);
+      return pair<reference_wrapper<const value>, bool> (*l, n);
     }
   }
 }
-- 
cgit