Implement missing pieces in utility libraries support

In particular, we can now build static libraries out of utility libraries.

1 files changed, 21 insertions, 3 deletions

diff --git a/build2/bin/target.hxx b/build2/bin/target.hxx
index f0b427f..0bcdf90 100644
--- a/build2/bin/target.hxx
+++ b/build2/bin/target.hxx
@@ -135,7 +135,7 @@ namespace build2
       virtual const target_type& dynamic_type () const {return static_type;}
     };
 
-    // Common base for lib{} and libu{} groups.
+    // Common base for lib{} and libul{}/libu{} groups.
     //
     // We use mtime_target as a base for the "trust me it exists" functionality
     // which we use, for example, to have installed lib{} prerequisites that
@@ -150,13 +150,21 @@ namespace build2
       static const target_type static_type;
     };
 
-    // The libu{} target group (utility library).
+    // The libul{}/libu{} target groups (utility library).
     //
-    // All the members are static libraries that differ base on the kind of
+    // All the members are static libraries that differ based on the kind of
     // object files they contains. Note that the group is more like obj{}
     // rather than lib{} in that one does not build the group directly rather
     // picking a suitable member.
     //
+    // libul{} is a "library utility library" in that the choice of members is
+    // libua{} or libus{}, even when linking an executable (normally a unit
+    // test).
+    //
+    // libu{} is a general utility library with all three types of members. It
+    // would normally be used when you want to build both a library from
+    // libua{}/libus{} and an executable from libue{}.
+    //
     class libux: public file // Common base of all libuX{} static libraries.
     {
     public:
@@ -196,6 +204,16 @@ namespace build2
       virtual const target_type& dynamic_type () const {return static_type;}
     };
 
+    class libul: public libx
+    {
+    public:
+      using libx::libx;
+
+    public:
+      static const target_type static_type;
+      virtual const target_type& dynamic_type () const {return static_type;}
+    };
+
     class libu: public libx
     {
     public: