From 23eb1973ba9fd1736d22452331b2d72b074e447d Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jurko=20Gospodneti=C4=87?= <jurko.gospodnetic@pke.hr>
Date: Sat, 11 Aug 2012 14:31:59 +0000
Subject: [PATCH] Boost Build cleanup - added a project.is-jamroot-module()
 rule (and an accompanying implementation detail
 project-attributes.is-jamroot() rule) to make testing whether a project
 module is a Jamroot module cleaner. As 'an example' updated the
 build-system.should-clean-project() rule to cleanly test for the Jamroot
 project module instead of assuming that Jamroot module is the one whose
 parent module is user-config. The old implementation was also incorrect since
 Jamroot may also have project-config as a parent.

[SVN r79967]
---
 src/build-system.jam  |  4 ++--
 src/build/project.jam | 18 ++++++++++++++++++
 2 files changed, 20 insertions(+), 2 deletions(-)

diff --git a/src/build-system.jam b/src/build-system.jam
index 8bbfe86d3..b79827bef 100644
--- a/src/build-system.jam
+++ b/src/build-system.jam
@@ -513,10 +513,10 @@ local rule should-clean-project ( project : detected-projects * )
         {
             r = true ;
         }
-        else
+        else if ! [ project.is-jamroot-module $(project) ]
         {
             local parent = [ project.attribute $(project) parent-module ] ;
-            if $(parent) && $(parent) != user-config
+            if $(parent)
             {
                 r = [ should-clean-project $(parent) : $(detected-projects) ] ;
             }
diff --git a/src/build/project.jam b/src/build/project.jam
index d947caf07..c345d8209 100644
--- a/src/build/project.jam
+++ b/src/build/project.jam
@@ -746,6 +746,16 @@ class project-attributes
         return $(self.$(attribute)) ;
     }
 
+    # Returns whether these attributes belong to a Jamroot project module.
+    #
+    rule is-jamroot ( )
+    {
+        if $(self.location) && $(self.project-root) = $(self.location)
+        {
+            return true ;
+        }
+    }
+
     # Prints the project attributes.
     #
     rule print ( )
@@ -811,6 +821,14 @@ rule attribute ( project attribute )
 }
 
 
+# Returns whether a project module is a Jamroot project module.
+#
+rule is-jamroot-module ( project )
+{
+    return [ $($(project).attributes).is-jamroot ] ;
+}
+
+
 # Returns the project target corresponding to the 'project-module'.
 #
 rule target ( project-module )