build two BPL targets: libboost_python and libboost_python3

[SVN r55456]

build/Jamfile.v2

@@ -4,6 +4,7 @@
 
 import os ;
 import modules ;
+import feature ;
 
 import python ;
 
@@ -22,6 +23,22 @@ if ! [ python.configured ] && ! ( --without-python in  [ modules.peek : ARGV ] )
     }
 }
 
+rule find-py3-version
+{
+    local versions = [ feature.values python ] ;
+    local py3ver ;
+    for local v in $(versions)
+    {
+        if $(v) >= 3.0
+        {
+            py3ver = $(v) ;
+        }
+    }
+    return $(py3ver) ;
+}
+
+py3-version = [ find-py3-version ] ;
+
 project boost/python
   : source-location ../src
   ;
@@ -29,66 +46,79 @@ project boost/python
 rule cond ( test ? : yes * : no * ) { if $(test) { return $(yes) ; } else { return $(no) ; } }
 rule unless ( test ? : yes * : no * ) { if ! $(test) { return $(yes) ; } else { return $(no) ; } }
 
-lib boost_python
-    : # sources
-    numeric.cpp
-    list.cpp
-    long.cpp
-    dict.cpp
-    tuple.cpp
-    str.cpp
-    slice.cpp
+rule lib_boost_python ( is-py3 ? )
+{
 
-    converter/from_python.cpp
-    converter/registry.cpp
-    converter/type_id.cpp
-    object/enum.cpp
-    object/class.cpp
-    object/function.cpp
-    object/inheritance.cpp
-    object/life_support.cpp
-    object/pickle_support.cpp
-    errors.cpp
-    module.cpp
-    converter/builtin_converters.cpp
-    converter/arg_to_python_base.cpp
-    object/iterator.cpp
-    object/stl_iterator.cpp
-    object_protocol.cpp
-    object_operators.cpp
-    wrapper.cpp
-    import.cpp
-    exec.cpp
-    object/function_doc_signature.cpp
-    :   # requirements
-        <link>static:<define>BOOST_PYTHON_STATIC_LIB 
-        <define>BOOST_PYTHON_SOURCE
-      
-        # On Windows, all code using Python has to link to the Python
-        # import library.
-        #
-        # On *nix we never link libboost_python to libpython.  When
-        # extending Python, all Python symbols are provided by the
-        # Python interpreter executable.  When embedding Python, the
-        # client executable is expected to explicitly link to
-        # /python//python (the target representing libpython) itself.
-        #
-        # python_for_extensions is a target defined by Boost.Build to
-        # provide the Python include paths, and on Windows, the Python
-        # import library, as usage requirements.
-        [ cond [ python.configured ] : <library>/python//python_for_extensions ]
-        
-        # we prevent building when there is no python available
-        # as it's not possible anyway, and to cause dependents to
-        # fail to build
-        [ unless [ python.configured ] : <build>no ]
+    lib [ cond $(is-py3) : boost_python3 : boost_python ]
+        : # sources
+        numeric.cpp
+        list.cpp
+        long.cpp
+        dict.cpp
+        tuple.cpp
+        str.cpp
+        slice.cpp
 
-        <python-debugging>on:<define>BOOST_DEBUG_PYTHON
-    :   # default build
-        <link>shared
-    :   # usage requirements
-        <link>static:<define>BOOST_PYTHON_STATIC_LIB
-        <python-debugging>on:<define>BOOST_DEBUG_PYTHON
-    ;
+        converter/from_python.cpp
+        converter/registry.cpp
+        converter/type_id.cpp
+        object/enum.cpp
+        object/class.cpp
+        object/function.cpp
+        object/inheritance.cpp
+        object/life_support.cpp
+        object/pickle_support.cpp
+        errors.cpp
+        module.cpp
+        converter/builtin_converters.cpp
+        converter/arg_to_python_base.cpp
+        object/iterator.cpp
+        object/stl_iterator.cpp
+        object_protocol.cpp
+        object_operators.cpp
+        wrapper.cpp
+        import.cpp
+        exec.cpp
+        object/function_doc_signature.cpp
+        :   # requirements
+            <link>static:<define>BOOST_PYTHON_STATIC_LIB 
+            <define>BOOST_PYTHON_SOURCE
+          
+            # On Windows, all code using Python has to link to the Python
+            # import library.
+            #
+            # On *nix we never link libboost_python to libpython.  When
+            # extending Python, all Python symbols are provided by the
+            # Python interpreter executable.  When embedding Python, the
+            # client executable is expected to explicitly link to
+            # /python//python (the target representing libpython) itself.
+            #
+            # python_for_extensions is a target defined by Boost.Build to
+            # provide the Python include paths, and on Windows, the Python
+            # import library, as usage requirements.
+            [ cond [ python.configured ] : <library>/python//python_for_extensions ]
+            
+            # we prevent building when there is no python available
+            # as it's not possible anyway, and to cause dependents to
+            # fail to build
+            [ unless [ python.configured ] : <build>no ]
 
+            <python-debugging>on:<define>BOOST_DEBUG_PYTHON
+            [ cond $(is-py3) : <python>$(py3-version) ]
+        :   # default build
+            <link>shared
+        :   # usage requirements
+            <link>static:<define>BOOST_PYTHON_STATIC_LIB
+            <python-debugging>on:<define>BOOST_DEBUG_PYTHON
+        ;
+
+}
+
+lib_boost_python ;
 boost-install boost_python ;
+
+if $(py3-version)
+{
+    lib_boost_python yes ;
+    boost-install boost_python3 ;
+}