Add support for default extension specification, trailing dot escaping

For example:

cxx{*}: extension = cxx

cxx{foo}         # foo.cxx
cxx{foo.test}    # foo.test      (probably what we want...)
cxx{foo.test...} # foo.test.cxx  (... is this)
cxx{foo..}       # foo.
cxx{foo....}     # foo..
cxx{foo.....}    # error (must come in escape pair)

1 files changed, 5 insertions, 1 deletions

diff --git a/build2/target-type.hxx b/build2/target-type.hxx
index 408a520..5027823 100644
--- a/build2/target-type.hxx
+++ b/build2/target-type.hxx
@@ -60,7 +60,11 @@ namespace build2
                                            const char*,
                                            bool search);
 
-    bool (*pattern) (const target_type&, const scope&, string&, bool reverse);
+    bool (*pattern) (const target_type&,
+                     const scope&,
+                     string& name,
+                     optional<string>& extension,
+                     bool reverse);
 
     void (*print) (ostream&, const target_key&);