Rework module architecture

Now the target type and rule maps are in scopes (builtins -- in global
scope). We also now have the map of loaded modules in the root scope of
each project.

1 files changed, 31 insertions, 1 deletions

diff --git a/build/module.cxx b/build/module.cxx
index 6b410e6..0f2b1b2 100644
--- a/build/module.cxx
+++ b/build/module.cxx
@@ -4,9 +4,39 @@
 
 #include <build/module>
 
+#include <utility> // make_pair()
+
+#include <build/scope>
+#include <build/diagnostics>
+
 using namespace std;
 
 namespace build
 {
-  module_map modules;
+  available_module_map builtin_modules;
+
+  void
+  load_module (const string& name, scope& root, scope& base, const location& l)
+  {
+    // First see if this modules has already been loaded for this
+    // project.
+    //
+    loaded_module_map& lm (root.modules);
+    auto i (lm.find (name));
+    bool f (i == lm.end ());
+
+    if (f)
+    {
+      // Otherwise search for this module.
+      //
+      auto j (builtin_modules.find (name));
+
+      if (j == builtin_modules.end ())
+        fail (l) << "unknown module " << name;
+
+      i = lm.emplace (name, make_pair (j->second, nullptr)).first;
+    }
+
+    i->second.first (root, base, l, i->second.second, f);
+  }
 }