bitbake: siggen: Pass all data caches to hash functions

Passing all the data caches to the task hashing functions allows them to
correctly account for mcdepends in task signatures. This allows tasks to
be correctly re-run when a mcdepends changes.

By default, the legacy behavior is maintained for derived signature
generators by passing a special proxy object that can either be used to
access all multiconfigs or the legacy behavior. If a derived signature
generator is updated, it can set the supports_multiconfig_datacaces
property to instruct bitbake it deals with multiconfigs properly.

[YOCTO #13724]

Signed-off-by: Joshua Watt <JPEWhacker@gmail.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

2 files changed, 67 insertions, 19 deletions

diff --git a/lib/bb/runqueue.py b/lib/bb/runqueue.py
index 5b7dab8d7..adb34a8cf 100644
--- a/lib/bb/runqueue.py
+++ b/lib/bb/runqueue.py
@@ -1190,8 +1190,9 @@ class RunQueueData:
         return len(self.runtaskentries)
 
     def prepare_task_hash(self, tid):
-        bb.parse.siggen.prep_taskhash(tid, self.runtaskentries[tid].depends, self.dataCaches[mc_from_tid(tid)])
-        self.runtaskentries[tid].hash = bb.parse.siggen.get_taskhash(tid, self.runtaskentries[tid].depends, self.dataCaches[mc_from_tid(tid)])
+        dc = bb.parse.siggen.get_data_caches(self.dataCaches, mc_from_tid(tid))
+        bb.parse.siggen.prep_taskhash(tid, self.runtaskentries[tid].depends, dc)
+        self.runtaskentries[tid].hash = bb.parse.siggen.get_taskhash(tid, self.runtaskentries[tid].depends, dc)
         self.runtaskentries[tid].unihash = bb.parse.siggen.get_unihash(tid)
 
     def dump_data(self):
@@ -2305,7 +2306,8 @@ class RunQueueExecute:
                 if len(self.rqdata.runtaskentries[p].depends) and not self.rqdata.runtaskentries[tid].depends.isdisjoint(total):
                     continue
                 orighash = self.rqdata.runtaskentries[tid].hash
-                newhash = bb.parse.siggen.get_taskhash(tid, self.rqdata.runtaskentries[tid].depends, self.rqdata.dataCaches[mc_from_tid(tid)])
+                dc = bb.parse.siggen.get_data_caches(self.rqdata.dataCaches, mc_from_tid(tid))
+                newhash = bb.parse.siggen.get_taskhash(tid, self.rqdata.runtaskentries[tid].depends, dc)
                 origuni = self.rqdata.runtaskentries[tid].unihash
                 newuni = bb.parse.siggen.get_unihash(tid)
                 # FIXME, need to check it can come from sstate at all for determinism?
diff --git a/lib/bb/siggen.py b/lib/bb/siggen.py
index 4c8d81c5d..872333d7f 100644
--- a/lib/bb/siggen.py
+++ b/lib/bb/siggen.py
@@ -38,6 +38,11 @@ class SignatureGenerator(object):
     """
     name = "noop"
 
+    # If the derived class supports multiconfig datacaches, set this to True
+    # The default is False for backward compatibility with derived signature
+    # generators that do not understand multiconfig caches
+    supports_multiconfig_datacaches = False
+
     def __init__(self, data):
         self.basehash = {}
         self.taskhash = {}
@@ -58,10 +63,10 @@ class SignatureGenerator(object):
     def get_unihash(self, tid):
         return self.taskhash[tid]
 
-    def prep_taskhash(self, tid, deps, dataCache):
+    def prep_taskhash(self, tid, deps, dataCaches):
         return
 
-    def get_taskhash(self, tid, deps, dataCache):
+    def get_taskhash(self, tid, deps, dataCaches):
         self.taskhash[tid] = hashlib.sha256(tid.encode("utf-8")).hexdigest()
         return self.taskhash[tid]
 
@@ -105,6 +110,38 @@ class SignatureGenerator(object):
     def set_setscene_tasks(self, setscene_tasks):
         return
 
+    @classmethod
+    def get_data_caches(cls, dataCaches, mc):
+        """
+        This function returns the datacaches that should be passed to signature
+        generator functions. If the signature generator supports multiconfig
+        caches, the entire dictionary of data caches is sent, otherwise a
+        special proxy is sent that support both index access to all
+        multiconfigs, and also direct access for the default multiconfig.
+
+        The proxy class allows code in this class itself to always use
+        multiconfig aware code (to ease maintenance), but derived classes that
+        are unaware of multiconfig data caches can still access the default
+        multiconfig as expected.
+
+        Do not override this function in derived classes; it will be removed in
+        the future when support for multiconfig data caches is mandatory
+        """
+        class DataCacheProxy(object):
+            def __init__(self):
+                pass
+
+            def __getitem__(self, key):
+                return dataCaches[key]
+
+            def __getattr__(self, name):
+                return getattr(dataCaches[mc], name)
+
+        if cls.supports_multiconfig_datacaches:
+            return dataCaches
+
+        return DataCacheProxy()
+
 class SignatureGeneratorBasic(SignatureGenerator):
     """
     """
@@ -200,7 +237,7 @@ class SignatureGeneratorBasic(SignatureGenerator):
         self.lookupcache = {}
         self.taskdeps = {}
 
-    def rundep_check(self, fn, recipename, task, dep, depname, dataCache):
+    def rundep_check(self, fn, recipename, task, dep, depname, dataCaches):
         # Return True if we should keep the dependency, False to drop it
         # We only manipulate the dependencies for packages not in the whitelist
         if self.twl and not self.twl.search(recipename):
@@ -218,37 +255,40 @@ class SignatureGeneratorBasic(SignatureGenerator):
             pass
         return taint
 
-    def prep_taskhash(self, tid, deps, dataCache):
+    def prep_taskhash(self, tid, deps, dataCaches):
 
         (mc, _, task, fn) = bb.runqueue.split_tid_mcfn(tid)
 
-        self.basehash[tid] = dataCache.basetaskhash[tid]
+        self.basehash[tid] = dataCaches[mc].basetaskhash[tid]
         self.runtaskdeps[tid] = []
         self.file_checksum_values[tid] = []
-        recipename = dataCache.pkg_fn[fn]
+        recipename = dataCaches[mc].pkg_fn[fn]
 
         self.tidtopn[tid] = recipename
 
         for dep in sorted(deps, key=clean_basepath):
-            (depmc, _, deptaskname, depfn) = bb.runqueue.split_tid_mcfn(dep)
-            if mc != depmc:
+            (depmc, _, _, depmcfn) = bb.runqueue.split_tid_mcfn(dep)
+            depname = dataCaches[depmc].pkg_fn[depmcfn]
+            if not self.supports_multiconfig_datacaches and mc != depmc:
+                # If the signature generator doesn't understand multiconfig
+                # data caches, any dependency not in the same multiconfig must
+                # be skipped for backward compatibility
                 continue
-            depname = dataCache.pkg_fn[depfn]
-            if not self.rundep_check(fn, recipename, task, dep, depname, dataCache):
+            if not self.rundep_check(fn, recipename, task, dep, depname, dataCaches):
                 continue
             if dep not in self.taskhash:
                 bb.fatal("%s is not in taskhash, caller isn't calling in dependency order?" % dep)
             self.runtaskdeps[tid].append(dep)
 
-        if task in dataCache.file_checksums[fn]:
+        if task in dataCaches[mc].file_checksums[fn]:
             if self.checksum_cache:
-                checksums = self.checksum_cache.get_checksums(dataCache.file_checksums[fn][task], recipename, self.localdirsexclude)
+                checksums = self.checksum_cache.get_checksums(dataCaches[mc].file_checksums[fn][task], recipename, self.localdirsexclude)
             else:
-                checksums = bb.fetch2.get_file_checksums(dataCache.file_checksums[fn][task], recipename, self.localdirsexclude)
+                checksums = bb.fetch2.get_file_checksums(dataCaches[mc].file_checksums[fn][task], recipename, self.localdirsexclude)
             for (f,cs) in checksums:
                 self.file_checksum_values[tid].append((f,cs))
 
-        taskdep = dataCache.task_deps[fn]
+        taskdep = dataCaches[mc].task_deps[fn]
         if 'nostamp' in taskdep and task in taskdep['nostamp']:
             # Nostamp tasks need an implicit taint so that they force any dependent tasks to run
             if tid in self.taints and self.taints[tid].startswith("nostamp:"):
@@ -259,14 +299,14 @@ class SignatureGeneratorBasic(SignatureGenerator):
                 taint = str(uuid.uuid4())
                 self.taints[tid] = "nostamp:" + taint
 
-        taint = self.read_taint(fn, task, dataCache.stamp[fn])
+        taint = self.read_taint(fn, task, dataCaches[mc].stamp[fn])
         if taint:
             self.taints[tid] = taint
             logger.warning("%s is tainted from a forced run" % tid)
 
         return
 
-    def get_taskhash(self, tid, deps, dataCache):
+    def get_taskhash(self, tid, deps, dataCaches):
 
         data = self.basehash[tid]
         for dep in self.runtaskdeps[tid]:
@@ -640,6 +680,12 @@ class SignatureGeneratorTestEquivHash(SignatureGeneratorUniHashMixIn, SignatureG
         self.server = data.getVar('BB_HASHSERVE')
         self.method = "sstate_output_hash"
 
+#
+# Dummy class used for bitbake-selftest
+#
+class SignatureGeneratorTestMulticonfigDepends(SignatureGeneratorBasicHash):
+    name = "TestMulticonfigDepends"
+    supports_multiconfig_datacaches = True
 
 def dump_this_task(outfile, d):
     import bb.parse