bitbake: ensure -f causes dependent tasks to be re-run

If -f is specified, force dependent tasks to be re-run next time. This
works by changing the force behaviour so that instead of deleting the
task's stamp, we write a "taint" file into the stamps directory, which
will alter the taskhash randomly and thus trigger the task to re-run
next time we evaluate whether or not that should be done as well as
influencing the taskhashes of any dependent tasks so that they are
similarly re-triggered. As a bonus because we write this file as
<stamp file name>.taskname.taint, the existing code which deletes the
stamp files in OE's do_clean will already handle removing it.

This means you can now do the following:

bitbake somepackage
[ change the source code in the package's WORKDIR ]
bitbake -c compile -f somepackage
bitbake somepackage

and the result will be that all of the tasks that depend on do_compile
(do_install, do_package, etc.) will be re-run in the last step.

Note that to operate in the manner described above you need full hashing
enabled (i.e. BB_SIGNATURE_HANDLER must be set to a signature handler
that inherits from BasicHash). If this is not the case, -f will just
delete the stamp for the specified task as it did before.

This fix is required for [YOCTO #2615] and [YOCTO #2256].

Signed-off-by: Paul Eggleton <paul.eggleton@linux.intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

1 files changed, 3 insertions, 3 deletions

diff --git a/lib/bb/cooker.py b/lib/bb/cooker.py
index 928b6009a..9b8d4b23e 100644
--- a/lib/bb/cooker.py
+++ b/lib/bb/cooker.py
@@ -1066,10 +1066,10 @@ class BBCooker:
         self.status.rundeps[fn] = []
         self.status.runrecs[fn] = []
 
-        # Remove stamp for target if force mode active
+        # Invalidate task for target if force mode active
         if self.configuration.force:
-            logger.verbose("Remove stamp %s, %s", task, fn)
-            bb.build.del_stamp('do_%s' % task, self.status, fn)
+            logger.verbose("Invalidate task %s, %s", task, fn)
+            bb.parse.siggen.invalidate_task('do_%s' % task, self.status, fn)
 
         # Setup taskdata structure
         taskdata = bb.taskdata.TaskData(self.configuration.abort)