Fix corner case in distributing via obj{}, libul{} groups

4 files changed, 102 insertions, 3 deletions

diff --git a/libbuild2/bin/init.cxx b/libbuild2/bin/init.cxx
index d7c5b5a..78119cb 100644
--- a/libbuild2/bin/init.cxx
+++ b/libbuild2/bin/init.cxx
@@ -605,6 +605,18 @@ namespace build2
 
         if (rs.find_module ("dist"))
         {
+          // Note that without custom dist rules in setups along the follwing
+          // lines the source file will be unreachable by dist:
+          //
+          // lib{foo}: obj{foo}
+          // obja{foo}: cxx{foo}
+          // objs{foo}: cxx{foo}
+          //
+          r.insert<obj> (dist_id, 0, "bin.obj", obj_);
+          r.insert<bmi> (dist_id, 0, "bin.bmi", obj_);
+          r.insert<hbmi> (dist_id, 0, "bin.hbmi", obj_);
+          r.insert<libul> (dist_id, 0, "bin.libul", libul_);
+
           r.insert<lib> (dist_id, 0, "bin.lib", lib_);
         }
       }
diff --git a/libbuild2/bin/rule.cxx b/libbuild2/bin/rule.cxx
index 27c9b4b..c7147bf 100644
--- a/libbuild2/bin/rule.cxx
+++ b/libbuild2/bin/rule.cxx
@@ -17,11 +17,29 @@ namespace build2
 {
   namespace bin
   {
+    // Search for an existing (declared real) member and match it if found.
+    //
+    static void
+    dist_match (action a, target& t, const target_type& tt)
+    {
+      if (const target* m = search_existing (t.ctx, tt, t.dir, t.out, t.name))
+      {
+        // Only a real target declaration can have prerequisites (which is
+        // the reason we are doing this).
+        //
+        if (m->decl == target_decl::real)
+          match_sync (a, *m);
+      }
+    }
+
     // obj_rule
     //
     bool obj_rule::
     match (action a, target& t) const
     {
+      if (a.meta_operation () == dist_id)
+        return true;
+
       const char* n (t.dynamic_type->name); // Ignore derived type.
 
       fail << diag_doing (a, t) << " target group" <<
@@ -30,7 +48,43 @@ namespace build2
     }
 
     recipe obj_rule::
-    apply (action, target&) const {return empty_recipe;}
+    apply (action a, target& t) const
+    {
+      // We only get here for dist.
+      //
+      const target_type* ett (nullptr);
+      const target_type* att (nullptr);
+      const target_type* stt (nullptr);
+
+      if (t.is_a<obj> ())
+      {
+        ett = &obje::static_type;
+        att = &obja::static_type;
+        stt = &objs::static_type;
+      }
+      else if (t.is_a<bmi> ())
+      {
+        ett = &bmie::static_type;
+        att = &bmia::static_type;
+        stt = &bmis::static_type;
+      }
+      else if (t.is_a<hbmi> ())
+      {
+        ett = &hbmie::static_type;
+        att = &hbmia::static_type;
+        stt = &hbmis::static_type;
+      }
+      else
+        assert (false);
+
+      dist_match (a, t, *ett);
+      dist_match (a, t, *att);
+      dist_match (a, t, *stt);
+
+      // Delegate to the default dist rule to match prerequisites.
+      //
+      return dist::rule::apply (a, t);
+    }
 
     // libul_rule
     //
@@ -43,6 +97,16 @@ namespace build2
     recipe libul_rule::
     apply (action a, target& t) const
     {
+      if (a.meta_operation () == dist_id)
+      {
+        dist_match (a, t, libua::static_type);
+        dist_match (a, t, libus::static_type);
+
+        // Delegate to the default dist rule to match prerequisites.
+        //
+        return dist::rule::apply (a, t);
+      }
+
       // Pick one of the members. First looking for the one already matched.
       //
       const target* m (nullptr);
@@ -113,6 +177,11 @@ namespace build2
     // The whole logic is pretty much as if we had our two group members as
     // our prerequisites.
     //
+    // Note also that unlike the obj and libul rules above, we don't need to
+    // delegate to the default dist rule since any group prerequisites will be
+    // matched by one of the members (the key difference here is that unlike
+    // those rules, we insert and match members unconditionally).
+    //
     bool lib_rule::
     match (action a, target& xt) const
     {
diff --git a/libbuild2/bin/rule.hxx b/libbuild2/bin/rule.hxx
index b403433..9dd1d14 100644
--- a/libbuild2/bin/rule.hxx
+++ b/libbuild2/bin/rule.hxx
@@ -9,6 +9,8 @@
 
 #include <libbuild2/rule.hxx>
 
+#include <libbuild2/dist/rule.hxx>
+
 #include <libbuild2/bin/export.hxx>
 
 namespace build2
@@ -18,7 +20,10 @@ namespace build2
     // "Fail rule" for obj{} and [h]bmi{} that issues diagnostics if someone
     // tries to build these groups directly.
     //
-    class obj_rule: public simple_rule
+    // Note that for dist it acts as a pass-through to all existing (declared)
+    // members.
+    //
+    class obj_rule: public dist::rule
     {
     public:
       obj_rule () {}
@@ -39,7 +44,10 @@ namespace build2
     // falling back to making our own based on bin.lib and bin.exe.lib. Note
     // that for update this rule always returns target_state::unchanged.
     //
-    class libul_rule: public simple_rule
+    // Note also that for dist it acts as a pass-through to all existing
+    // (declared) members.
+    //
+    class libul_rule: public dist::rule
     {
     public:
       explicit
@@ -54,6 +62,8 @@ namespace build2
 
     // Pass-through to group members rule, similar to alias.
     //
+    // Note that for dist it always passes to both members.
+    //
     class LIBBUILD2_BIN_SYMEXPORT lib_rule: public simple_rule
     {
     public:
diff --git a/libbuild2/bin/target.hxx b/libbuild2/bin/target.hxx
index 3ecabce..9685e39 100644
--- a/libbuild2/bin/target.hxx
+++ b/libbuild2/bin/target.hxx
@@ -71,6 +71,8 @@ namespace build2
       static const target_type static_type;
     };
 
+    // Note: this is a "choice" target group.
+    //
     class LIBBUILD2_BIN_SYMEXPORT obj: public target
     {
     public:
@@ -219,6 +221,8 @@ namespace build2
       static const target_type static_type;
     };
 
+    // Note: this is a "choice" target group (similar to obj{}).
+    //
     class LIBBUILD2_BIN_SYMEXPORT bmi: public target
     {
     public:
@@ -232,6 +236,8 @@ namespace build2
       static const target_type static_type;
     };
 
+    // Note: this is a "choice" target group (similar to bmi{} and obj{}).
+    //
     class LIBBUILD2_BIN_SYMEXPORT hbmi: public target
     {
     public:
@@ -340,6 +346,8 @@ namespace build2
       static const target_type static_type;
     };
 
+    // Note: this is a "choice" target group.
+    //
     // @@ Ideally this shouldn't derive from mtime_target (via libx). Maybe
     //    get rid of libx?
     //