Implement two-phase initialization of modules loaded from bootstrap.build

2 files changed, 31 insertions, 18 deletions

diff --git a/build/config/module b/build/config/module
index 530fa7b..3e43c7b 100644
--- a/build/config/module
+++ b/build/config/module
@@ -14,6 +14,9 @@ namespace build
 {
   namespace config
   {
+    extern "C" void
+    config_boot (scope&, const location&, unique_ptr<module>&);
+
     extern "C" bool
     config_init (
     scope&, scope&, const location&, unique_ptr<module>&, bool, bool);
diff --git a/build/config/module.cxx b/build/config/module.cxx
index 77a786b..c9139ed 100644
--- a/build/config/module.cxx
+++ b/build/config/module.cxx
@@ -24,9 +24,35 @@ namespace build
     //
     static const path config_file ("build/config.build");
 
+    extern "C" void
+    config_boot (scope& root, const location&, unique_ptr<module>&)
+    {
+      tracer trace ("config::boot");
+
+      const dir_path& out_root (root.out_path ());
+      level5 ([&]{trace << "for " << out_root;});
+
+      // Register meta-operations.
+      //
+      root.meta_operations.insert (configure_id, configure);
+      root.meta_operations.insert (disfigure_id, disfigure);
+
+      // Load config.build if one exists.
+      //
+      // Note that we have to do this during bootstrap since the order in
+      // which the modules will be initialized is unspecified. So it is
+      // possible that some module which needs the configuration will get
+      // called first.
+      //
+      path f (out_root / config_file);
+
+      if (file_exists (f))
+        source (f, root, root);
+    }
+
     extern "C" bool
     config_init (scope& root,
-                 scope& base,
+                 scope&,
                  const location& l,
                  std::unique_ptr<module>&,
                  bool first,
@@ -34,22 +60,13 @@ namespace build
     {
       tracer trace ("config::init");
 
-      if (&root != &base)
-        fail (l) << "config module must be initialized in bootstrap.build";
-
       if (!first)
       {
         warn (l) << "multiple config module initializations";
         return true;
       }
 
-      const dir_path& out_root (root.out_path ());
-      level5 ([&]{trace << "for " << out_root;});
-
-      // Register meta-operations.
-      //
-      root.meta_operations.insert (configure_id, configure);
-      root.meta_operations.insert (disfigure_id, disfigure);
+      level5 ([&]{trace << "for " << root.out_path ();});
 
       // Register alias and fallback rule for the configure meta-operation.
       //
@@ -67,13 +84,6 @@ namespace build
         r.insert<alias> (configure_id, 0, "config.alias", alias_rule::instance);
       }
 
-      // Load config.build if one exists.
-      //
-      path f (out_root / config_file);
-
-      if (file_exists (f))
-        source (f, root, root);
-
       return true;
     }
   }