Tests: Allow removal of objects on the fly

Add another option to allow deletion of unused objects
on the fly.
This option should be used with care. It is recommended
to run without -d (or --delete) beforehand and check the
results.
Anyhow, when deletion is wanted it processes as usual,
renames the original objects.map to objects.map~ and
recreates the objects.map without the objects that
could be deleted.

Change-Id: I3898e8b9998e33461140bf4c75887a32d106f22c
Reviewed-by: Robert Loehning <robert.loehning@qt.io>

tests/system/tools/findUnusedObjects.py

@@ -38,11 +38,13 @@ lastToken = [None, None]
 stopTokens = ('OP', 'NAME', 'NUMBER', 'ENDMARKER')
 
 def parseCommandLine():
-    global directory, onlyRemovable, sharedFolders
+    global directory, onlyRemovable, sharedFolders, deleteObjects
     parser = OptionParser("\n%prog [OPTIONS] [DIRECTORY]")
     parser.add_option("-o", "--only-removable", dest="onlyRemovable",
                       action="store_true", default=False,
                       help="list removable objects only")
+    parser.add_option("-d", "--delete", dest="delete",
+                      action="store_true", default=False)
     parser.add_option("-s", dest="sharedFolders",
                       action="store", type="string", default="",
                       help="comma-separated list of shared folders")
@@ -56,6 +58,7 @@ def parseCommandLine():
         parser.print_help()
         sys.exit(1)
     onlyRemovable = options.onlyRemovable
+    deleteObjects = options.delete
     sharedFolders = map(os.path.abspath, options.sharedFolders.split(','))
 
 def collectObjects():
@@ -153,15 +156,53 @@ def printResult():
         print
     return None
 
-def main():
+def deleteRemovable():
     global useCounts, objMap
+
+    deletable = filter(lambda x: useCounts[x] == 0, useCounts)
+    if len(deletable) == 0:
+        print("Nothing to delete - leaving objects.map untouched")
+        return
+
+    data = ''
+    with open(objMap, "r") as objMapFile:
+        data = objMapFile.read()
+
+    objMapBackup = objMap + '~'
+    if os.path.exists(objMapBackup):
+        os.unlink(objMapBackup)
+    os.rename(objMap, objMapBackup)
+
+    count = 0
+    with open(objMap, "w") as objMapFile:
+        for line in data.splitlines():
+            try:
+                obj = line.split('\t')[0]
+                if obj in deletable:
+                    count += 1
+                    continue
+                objMapFile.write(line + '\n')
+            except:
+                print("Something's wrong in line '%s'" % line)
+
+    print("Deleted %d items, old objects.map has been moved to objects.map~" % count)
+    return count > 0
+
+def main():
+    global useCounts, objMap, deleteObjects
     objMap = checkDirectory(directory)
     useCounts = dict.fromkeys(collectObjects(), 0)
     findUsages()
     atLeastOneRemovable = printResult()
+    deletedAtLeastOne = deleteObjects and deleteRemovable()
+
+    mssg = None
     if atLeastOneRemovable:
-        print "\nAfter removing the listed objects you should re-run this tool"
+        mssg = "\nAfter removing the listed objects you should re-run this tool\n"
-        print "to find objects that might have been used only by these objects.\n"
+    if deletedAtLeastOne:
+        mssg = "\nYou should re-run this tool\n"
+    if mssg:
+        print(mssg + "to find objects that might have been referenced only by removed objects.\n")
     return 0
 
 if __name__ == '__main__':