Lift architecture detection

Jamroot

@@ -136,7 +136,8 @@ constant BOOST_JAMROOT_MODULE : $(__name__) ;
 
 boostcpp.set-version $(BOOST_VERSION) ;
 
-	
+use-project /boost/architecture : libs/config/checks/architecture ;
+
 local all-headers =
     [ MATCH .*libs/(.*)/include/boost : [ glob libs/*/include/boost ] ] ;
 
@@ -162,6 +163,10 @@ if $(all-headers)
 
 project boost
     : requirements <include>.
+
+      [ boostcpp.architecture ]
+      [ boostcpp.address-model ]
+
       # Disable auto-linking for all targets here, primarily because it caused
       # troubles with V2.
       <define>BOOST_ALL_NO_LIB=1

boostcpp.jam

@@ -22,7 +22,7 @@ import project ;
 import regex ;
 import set ;
 import targets ;
-
+import property ;
 
 ##############################################################################
 #
@@ -553,3 +553,69 @@ rule declare-targets ( all-libraries * : headers * )
 
     declare_top_level_targets $(libraries) : $(headers) ;
 }
+
+rule deduce-address-model ( properties * )
+{
+    local result = [ property.select <address-model> : $(properties) ] ;
+    if $(result)
+    {
+        return $(result) ;
+    }
+    else
+    {
+        if [ configure.builds /boost/architecture//32 : $(properties) : 32-bit ]
+        {
+            return <address-model>32 ;
+        }
+        else if [ configure.builds /boost/architecture//64 : $(properties) : 64-bit ]
+        {
+            return <address-model>64 ;
+        }
+    }
+}
+
+rule address-model ( )
+{
+    return <conditional>@boostcpp.deduce-address-model ;
+}
+
+rule deduce-architecture ( properties * )
+{
+    local result = [ property.select <architecture> : $(properties) ] ;
+    if $(result)
+    {
+        return $(result) ;
+    }
+    else
+    {
+        if [ configure.builds /boost/architecture//arm : $(properties) : arm ]
+        {
+            return <architecture>arm ;
+        }
+        else if [ configure.builds /boost/architecture//mips1 : $(properties) : mips1 ]
+        {
+            return <architecture>mips1 ;
+        }
+        else if [ configure.builds /boost/architecture//power : $(properties) : power ]
+        {
+            return <architecture>power ;
+        }
+        else if [ configure.builds /boost/architecture//sparc : $(properties) : sparc ]
+        {
+            return <architecture>sparc ;
+        }
+        else if [ configure.builds /boost/architecture//x86 : $(properties) : x86 ]
+        {
+            return <architecture>x86 ;
+        }
+        else if [ configure.builds /boost/architecture//combined : $(properties) : combined ]
+        {
+            return <architecture>combined ;
+        }
+    }
+}
+
+rule architecture ( )
+{
+    return <conditional>@boostcpp.deduce-architecture ;
+}