[bitbake-devel][RFC] bitbake: Report which dependencies affect the taskhash

[Joshua Watt <jpewhacker@gmail.com>]

Report which task dependencies in BB_TASKDEPDATA are included in the
taskhash. This allows tasks to identify which tasks dependencies may
change without the task re-running. Knowing this information is
important for tasks that want to transfer information from dependencies
(such as SPDX)

Signed-off-by: Joshua Watt <JPEWhacker@gmail.com>
---
 bitbake/lib/bb/runqueue.py | 8 +++++---
 bitbake/lib/bb/siggen.py   | 2 +-
 2 files changed, 6 insertions(+), 4 deletions(-)

diff --git a/bitbake/lib/bb/runqueue.py b/bitbake/lib/bb/runqueue.py
index bc7e18175dd..6b43f303d5a 100644
--- a/bitbake/lib/bb/runqueue.py
+++ b/bitbake/lib/bb/runqueue.py
@@ -1290,7 +1290,7 @@ class RunQueueData:
         return len(self.runtaskentries)
 
     def prepare_task_hash(self, tid):
-        bb.parse.siggen.prep_taskhash(tid, self.runtaskentries[tid].depends, self.dataCaches)
+        self.runtaskentries[tid].taskhash_deps = bb.parse.siggen.prep_taskhash(tid, self.runtaskentries[tid].depends, self.dataCaches)
         self.runtaskentries[tid].hash = bb.parse.siggen.get_taskhash(tid, self.runtaskentries[tid].depends, self.dataCaches)
         self.runtaskentries[tid].unihash = bb.parse.siggen.get_unihash(tid)
 
@@ -2445,7 +2445,8 @@ class RunQueueExecute:
             unihash = self.rqdata.runtaskentries[task].unihash
             deps = self.filtermcdeps(task, mc, deps)
             hashfn = self.rqdata.dataCaches[mc].hashfn[taskfn]
-            taskdepdata_cache[task] = [pn, taskname, fn, deps, provides, taskhash, unihash, hashfn]
+            taskhash_deps = self.rqdata.runtaskentries[task].taskhash_deps
+            taskdepdata_cache[task] = [pn, taskname, fn, deps, provides, taskhash, unihash, hashfn, taskhash_deps]
 
         self.taskdepdata_cache = taskdepdata_cache
 
@@ -2812,7 +2813,8 @@ class RunQueueExecute:
                 taskhash = self.rqdata.runtaskentries[revdep].hash
                 unihash = self.rqdata.runtaskentries[revdep].unihash
                 hashfn = self.rqdata.dataCaches[mc].hashfn[taskfn]
-                taskdepdata[revdep] = [pn, taskname, fn, deps, provides, taskhash, unihash, hashfn]
+                taskhash_deps = self.rqdata.runtaskentries[revdep].taskhash_deps
+                taskdepdata[revdep] = [pn, taskname, fn, deps, provides, taskhash, unihash, hashfn, taskhash_deps]
                 for revdep2 in deps:
                     if revdep2 not in taskdepdata:
                         additional.append(revdep2)
diff --git a/bitbake/lib/bb/siggen.py b/bitbake/lib/bb/siggen.py
index 8ab08ec961b..03dfda6f3c4 100644
--- a/bitbake/lib/bb/siggen.py
+++ b/bitbake/lib/bb/siggen.py
@@ -381,7 +381,7 @@ class SignatureGeneratorBasic(SignatureGenerator):
             self.taints[tid] = taint
             logger.warning("%s is tainted from a forced run" % tid)
 
-        return
+        return set(dep for _, dep in self.runtaskdeps[tid])
 
     def get_taskhash(self, tid, deps, dataCaches):
 
-- 
2.34.1