Make cxx.export.* machinery work for library chains

2 files changed, 23 insertions, 9 deletions

diff --git a/build/bin/rule.cxx b/build/bin/rule.cxx
index 06fe72e..22b7bc2 100644
--- a/build/bin/rule.cxx
+++ b/build/bin/rule.cxx
@@ -77,6 +77,22 @@ namespace build
         build::match (a, *t.so);
       }
 
+      // Search and match prerequisite libraries and add them to the
+      // prerequisite targets. While we never execute this list
+      // ourselves (see perform() below), this is necessary to make
+      // the exported options machinery work for the library chains.
+      // See cxx.export.*-related code in cxx/rule.cxx for details.
+      //
+      for (prerequisite& p: group_prerequisites (t))
+      {
+        if (p.is_a<lib> () || p.is_a<liba> () || p.is_a<libso> ())
+        {
+          target& pt (search (p));
+          build::match (a, pt);
+          t.prerequisite_targets.push_back (&pt);
+        }
+      }
+
       return &perform;
     }
 
diff --git a/build/cxx/rule.cxx b/build/cxx/rule.cxx
index d5a9b9c..4fce59a 100644
--- a/build/cxx/rule.cxx
+++ b/build/cxx/rule.cxx
@@ -839,20 +839,18 @@ namespace build
           //
           pt->prerequisites.emplace_back (cp);
 
-          // Add our imported lib*{} prerequisites to the object file (see
+          // Add our lib*{} prerequisites to the object file (see
           // cxx.export.poptions above for details).
           //
+          // Initially, we were only adding imported libraries, but
+          // there is a problem with this approach: the non-imported
+          // library might depend on the imported one(s) which we
+          // will never "see" unless we add this library as well.
+          //
           for (prerequisite& p: group_prerequisites (t))
           {
             if (p.is_a<lib> () || p.is_a<liba> () || p.is_a<libso> ())
-            {
-              // Check that it is imported, that is its root scope differs
-              // from ours.
-              //
-              if (p.dir.absolute () && // Imported is always absolute.
-                  scopes.find (p.dir).root_scope () != root)
-                pt->prerequisites.emplace_back (p);
-            }
+              pt->prerequisites.emplace_back (p);
           }
 
           build::match (a, *ot);