Make $config.origin() also available internally as config::origin()

1 files changed, 33 insertions, 0 deletions

diff --git a/libbuild2/config/utility.cxx b/libbuild2/config/utility.cxx
index a78b263..7437c5b 100644
--- a/libbuild2/config/utility.cxx
+++ b/libbuild2/config/utility.cxx
@@ -156,5 +156,38 @@ namespace build2
       else
         return false;
     }
+
+    pair<variable_origin, lookup>
+    origin (const scope& rs, const string& n)
+    {
+      // Make sure this is a config.* variable. This could matter since we
+      // reply on the semantics of value::extra. We could also detect
+      // special variables like config.booted, some config.config.*, etc.,
+      // (see config_save() for details) but that seems harmless.
+      //
+      if (n.compare (0, 7, "config.") != 0)
+        throw invalid_argument ("config.* variable expected");
+
+      const variable* var (rs.ctx.var_pool.find (n));
+
+      if (var == nullptr)
+        return make_pair (variable_origin::undefined, lookup ());
+
+      pair<lookup, size_t> org (rs.lookup_original (*var));
+      pair<lookup, size_t> ovr (var->overrides == nullptr
+                                ? org
+                                : rs.lookup_override (*var, org));
+
+      if (!ovr.first.defined ())
+        return make_pair (variable_origin::undefined, lookup ());
+
+      if (org.first != ovr.first)
+        return make_pair (variable_origin::override_, ovr.first);
+
+      return make_pair (org.first->extra
+                        ? variable_origin::default_
+                        : variable_origin::buildfile,
+                        org.first);
+    }
   }
 }