bitbake: 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].

(Bitbake rev: f7b55a94226f9acd985f87946e26d01bd86a35bb)

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

bitbake/lib/bb/runqueue.py

@@ -705,6 +705,12 @@ class RunQueueData:
                 continue
             self.runq_setscene.append(task)
 
+        # Invalidate task if force mode active
+        if self.cooker.configuration.force:
+            for (fn, target) in self.target_pairs:
+                logger.verbose("Invalidate task %s, %s", target, fn)
+                bb.parse.siggen.invalidate_task(target, self.dataCache, fn)
+
         # Interate over the task list and call into the siggen code
         dealtwith = set()
         todeal = set(range(len(self.runq_fnid)))
@@ -731,12 +737,6 @@ class RunQueueData:
                 deps.append(depidentifier)
             self.hash_deps[identifier] = deps
 
-        # Remove stamps for targets if force mode active
-        if self.cooker.configuration.force:
-            for (fn, target) in self.target_pairs:
-                logger.verbose("Remove stamp %s, %s", target, fn)
-                bb.build.del_stamp(target, self.dataCache, fn)
-
         return len(self.runq_fnid)
 
     def dump_data(self, taskQueue):