1 files changed, 54 insertions, 29 deletions

diff --git a/build/config/operation.cxx b/build/config/operation.cxx
index 6f5beba..f223028 100644
--- a/build/config/operation.cxx
+++ b/build/config/operation.cxx
@@ -127,52 +127,77 @@ namespace build
     }
 
     static void
-    configure_execute (action a, const action_targets& ts)
+    configure_project (action a, scope& root)
     {
-      tracer trace ("configure_execute");
+      tracer trace ("configure_project");
 
-      for (void* v: ts)
-      {
-        target& t (*static_cast<target*> (v));
-        scope* rs (t.root_scope ());
+      const path& out_root (root.path ());
+      const path& src_root (root.src_path ());
 
-        if (rs == nullptr)
-          fail << "out of project target " << t;
+      // Make sure the directories exist.
+      //
+      if (out_root != src_root)
+      {
+        mkdir (out_root);
+        mkdir (out_root / build_dir);
+        mkdir (out_root / bootstrap_dir);
+      }
 
-        const path& out_root (rs->path ());
-        const path& src_root (rs->src_path ());
+      // We distinguish between a complete configure and operation-
+      // specific.
+      //
+      if (a.operation () == default_id)
+      {
+        level4 ([&]{trace << "completely configuring " << out_root;});
 
-        // Make sure the directories exist.
+        // Save src-root.build unless out_root is the same as src.
         //
         if (out_root != src_root)
-        {
-          mkdir (out_root);
-          mkdir (out_root / build_dir);
-          mkdir (out_root / bootstrap_dir);
-        }
+          save_src_root (out_root, src_root);
 
-        // We distinguish between a complete configure and operation-
-        // specific.
+        // Save config.build.
         //
-        if (a.operation () == default_id)
+        save_config (root);
+      }
+      else
+      {
+      }
+
+      // Configure subprojects that have been loaded.
+      //
+      if (auto v = root.ro_variables ()["subprojects"])
+      {
+        for (const name& n: v.as<const list_value&> ().data)
         {
-          level4 ([&]{trace << "completely configuring " << out_root;});
+          path out_nroot (out_root / n.dir);
+          scope& nroot (scopes.find (out_nroot));
 
-          // Save src-root.build unless out_root is the same as src.
+          // @@ Strictly speaking we need to check whether the config
+          // module was loaded for this subproject.
           //
-          if (out_root != src_root)
-            save_src_root (out_root, src_root);
+          if (nroot.path () != out_nroot) // This subproject was not loaded.
+            continue;
 
-          // Save config.build.
-          //
-          save_config (*rs);
-        }
-        else
-        {
+          configure_project (a, nroot);
         }
       }
     }
 
+    static void
+    configure_execute (action a, const action_targets& ts)
+    {
+      for (void* v: ts)
+      {
+        target& t (*static_cast<target*> (v));
+        scope* rs (t.root_scope ());
+
+        if (rs == nullptr)
+          fail << "out of project target " << t;
+
+        configure_project (a, *rs);
+      }
+    }
+
     meta_operation_info configure {
       "configure",
       "configure",