data/siggen: Extract task hash generation code into a function

By creating a standalone function, we can add better functional testing
of this code.

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

2 files changed, 42 insertions, 33 deletions

diff --git a/lib/bb/data.py b/lib/bb/data.py
index fde4cba6b..d66d98cc8 100644
--- a/lib/bb/data.py
+++ b/lib/bb/data.py
@@ -38,6 +38,7 @@ the speed is more critical here.
 # Based on functions from the base bb module, Copyright 2003 Holger Schurig
 
 import sys, os, re
+import hashlib
 if sys.argv[0][-5:] == "pydoc":
     path = os.path.dirname(os.path.dirname(sys.argv[1]))
 else:
@@ -405,6 +406,43 @@ def generate_dependencies(d):
         #print "For %s: %s" % (task, str(deps[task]))
     return tasklist, deps, values
 
+def generate_dependency_hash(tasklist, gendeps, lookupcache, whitelist, fn):
+    taskdeps = {}
+    basehash = {}
+
+    for task in tasklist:
+        data = lookupcache[task]
+
+        if data is None:
+            bb.error("Task %s from %s seems to be empty?!" % (task, fn))
+            data = ''
+
+        gendeps[task] -= whitelist
+        newdeps = gendeps[task]
+        seen = set()
+        while newdeps:
+            nextdeps = newdeps
+            seen |= nextdeps
+            newdeps = set()
+            for dep in nextdeps:
+                if dep in whitelist:
+                    continue
+                gendeps[dep] -= whitelist
+                newdeps |= gendeps[dep]
+            newdeps -= seen
+
+        alldeps = sorted(seen)
+        for dep in alldeps:
+            data = data + dep
+            var = lookupcache[dep]
+            if var is not None:
+                data = data + str(var)
+        k = fn + "." + task
+        basehash[k] = hashlib.md5(data.encode("utf-8")).hexdigest()
+        taskdeps[task] = alldeps
+
+    return taskdeps, basehash
+
 def inherits_class(klass, d):
     val = d.getVar('__inherit_cache', False) or []
     needle = os.path.join('classes', '%s.bbclass' % klass)
diff --git a/lib/bb/siggen.py b/lib/bb/siggen.py
index e9bb51d73..03c824ec3 100644
--- a/lib/bb/siggen.py
+++ b/lib/bb/siggen.py
@@ -110,42 +110,13 @@ class SignatureGeneratorBasic(SignatureGenerator):
         ignore_mismatch = ((d.getVar("BB_HASH_IGNORE_MISMATCH") or '') == '1')
         tasklist, gendeps, lookupcache = bb.data.generate_dependencies(d)
 
-        taskdeps = {}
-        basehash = {}
+        taskdeps, basehash = bb.data.generate_dependency_hash(tasklist, gendeps, lookupcache, self.basewhitelist, fn)
 
         for task in tasklist:
-            data = lookupcache[task]
-
-            if data is None:
-                bb.error("Task %s from %s seems to be empty?!" % (task, fn))
-                data = ''
-
-            gendeps[task] -= self.basewhitelist
-            newdeps = gendeps[task]
-            seen = set()
-            while newdeps:
-                nextdeps = newdeps
-                seen |= nextdeps
-                newdeps = set()
-                for dep in nextdeps:
-                    if dep in self.basewhitelist:
-                        continue
-                    gendeps[dep] -= self.basewhitelist
-                    newdeps |= gendeps[dep]
-                newdeps -= seen
-
-            alldeps = sorted(seen)
-            for dep in alldeps:
-                data = data + dep
-                var = lookupcache[dep]
-                if var is not None:
-                    data = data + str(var)
-            datahash = hashlib.md5(data.encode("utf-8")).hexdigest()
             k = fn + "." + task
-            if not ignore_mismatch and k in self.basehash and self.basehash[k] != datahash:
-                bb.error("When reparsing %s, the basehash value changed from %s to %s. The metadata is not deterministic and this needs to be fixed." % (k, self.basehash[k], datahash))
-            self.basehash[k] = datahash
-            taskdeps[task] = alldeps
+            if not ignore_mismatch and k in self.basehash and self.basehash[k] != basehash[k]:
+                bb.error("When reparsing %s, the basehash value changed from %s to %s. The metadata is not deterministic and this needs to be fixed." % (k, self.basehash[k], basehash[k]))
+            self.basehash[k] = basehash[k]
 
         self.taskdeps[fn] = taskdeps
         self.gendeps[fn] = gendeps