bitbake: runqueue/siggen: Allow handling of equivalent hashes

Based on the hashserv's new ability to accept hash mappings, update runqueue
to use this through a helper function in siggen.

This addresses problems with meta-extsdk-toolchain and its dependency on
gdb-cross which caused errors when building eSDK. See the previous commit
for more details.

(Bitbake rev: 39098b4ba2133f4d9229a0aa4fcf4c3e1291286a)

Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

bitbake/lib/bb/siggen.py

@@ -525,6 +525,32 @@ class SignatureGeneratorUniHashMixIn(object):
                 except OSError:
                     pass
 
+    def report_unihash_equiv(self, tid, taskhash, wanted_unihash, current_unihash, datacaches):
+        try:
+            extra_data = {}
+            data = self.client().report_unihash_equiv(taskhash, self.method, wanted_unihash, extra_data)
+            bb.note('Reported task %s as unihash %s to %s (%s)' % (tid, wanted_unihash, self.server, str(data)))
+
+            if data is None:
+                bb.warn("Server unable to handle unihash report")
+                return False
+
+            finalunihash = data['unihash']
+
+            if finalunihash == current_unihash:
+                bb.note('Task %s unihash %s unchanged by server' % (tid, finalunihash))
+            elif finalunihash == wanted_unihash:
+                bb.note('Task %s unihash changed %s -> %s as wanted' % (tid, current_unihash, finalunihash))
+                self.set_unihash(tid, finalunihash)
+                return True
+            else:
+                # TODO: What to do here?
+                bb.note('Task %s unihash reported as unwanted hash %s' % (tid, finalunihash))
+
+        except hashserv.client.HashConnectionError as e:
+            bb.warn('Error contacting Hash Equivalence Server %s: %s' % (self.server, str(e)))
+
+        return False
 
 #
 # Dummy class used for bitbake-selftest