1 files changed, 18 insertions, 1 deletions

diff --git a/meta/classes/externalsrc.bbclass b/meta/classes/externalsrc.bbclass
index 6ec46a6b15..bdf23ec6be 100644
--- a/meta/classes/externalsrc.bbclass
+++ b/meta/classes/externalsrc.bbclass
@@ -4,7 +4,7 @@
 # Copyright (C) 2009 Chris Larson <clarson@kergoth.com>
 # Released under the MIT license (see COPYING.MIT for the terms)
 #
-# externalsrc.bbclass enables use of an existing source tree, usually external to 
+# externalsrc.bbclass enables use of an existing source tree, usually external to
 # the build system to build a piece of software rather than the usual fetch/unpack/patch
 # process.
 #
@@ -108,6 +108,10 @@ python () {
         # We don't want the workdir to go away
         d.appendVar('RM_WORK_EXCLUDE', ' ' + d.getVar('PN'))
 
+        bb.build.addtask('do_buildclean',
+                         'do_clean' if d.getVar('S') == d.getVar('B') else None,
+                         None, d)
+
         # If B=S the same builddir is used even for different architectures.
         # Thus, use a shared CONFIGURESTAMPFILE and STAMP directory so that
         # change of do_configure task hash is correctly detected and stamps are
@@ -143,6 +147,17 @@ python externalsrc_compile_prefunc() {
     bb.plain('NOTE: %s: compiling from external source tree %s' % (d.getVar('PN'), d.getVar('EXTERNALSRC')))
 }
 
+do_buildclean[dirs] = "${S} ${B}"
+do_buildclean[nostamp] = "1"
+do_buildclean[doc] = "Call 'make clean' or equivalent in ${B}"
+externalsrc_do_buildclean() {
+        if [ -e Makefile -o -e makefile -o -e GNUmakefile ]; then
+                oe_runmake clean || die "make failed"
+        else
+                bbnote "nothing to do - no makefile found"
+        fi
+}
+
 def srctree_hash_files(d, srcdir=None):
     import shutil
     import subprocess
@@ -189,3 +204,5 @@ def srctree_configure_hash_files(d):
                 if f in search_files:
                     out_items.append('%s:True' % os.path.join(root, f))
     return ' '.join(out_items)
+
+EXPORT_FUNCTIONS do_buildclean