CORD-2247: Write basic static checker for xproto

Change-Id: I63a96972e16fd8dd62d4dec840eede66cbb26368
diff --git a/lib/xos-genx/xosgenx/xosgen.py b/lib/xos-genx/xosgenx/xosgen.py
index 7893f22..fa734b5 100755
--- a/lib/xos-genx/xosgenx/xosgen.py
+++ b/lib/xos-genx/xosgenx/xosgen.py
@@ -21,7 +21,6 @@
 
 parse = argparse.ArgumentParser(description='XOS Generative Toolchain')
 parse.add_argument('--rev', dest='rev', action='store_true',default=False, help='Convert proto to xproto')
-parse.add_argument('--target', dest='target', action='store',default=None, help='Output format, corresponding to <output>.yaml file', required=True)
 parse.add_argument('--output', dest='output', action='store',default=None, help='Destination dir')
 parse.add_argument('--attic', dest='attic', action='store',default=None, help='The location at which static files are stored')
 parse.add_argument('--kvpairs', dest='kv', action='store',default=None, help='Key value pairs to make available to the target')
@@ -31,41 +30,67 @@
 group.add_argument('--dest-file', dest='dest_file', action='store',default=None, help='Output file name (if write-to-file is set to single)')
 group.add_argument('--dest-extension', dest='dest_extension', action='store',default=None, help='Output file extension (if write-to-file is set to single)')
 
+group = parse.add_mutually_exclusive_group(required=True)
+group.add_argument('--target', dest='target', action='store',default=None, help='Output format, corresponding to <output>.yaml file')
+group.add_argument('--checkers', dest='checkers', action='store', default=None, help='Comma-separated list of static checkers')
+
 parse.add_argument('files', metavar='<input file>', nargs='+', action='store', help='xproto files to compile')
 
+CHECK = 1
+GEN = 2
+
 class XosGen:
 
     @staticmethod
     def init(args=None):
-
         if not args:
             args = parse.parse_args()
 
         args.quiet = False
 
-        # convert output to absolute path
-        if args.output is not None and not os.path.isabs(args.output):
-            args.output = os.path.abspath(os.getcwd() + '/' + args.output)
-        if not '/' in args.target:
-            # if the target is not a path, it refer to a library included one
-            args.target = os.path.abspath(os.path.dirname(os.path.realpath(__file__)) + "/targets/" + args.target)
-        if not os.path.isabs(args.target):
-            args.target = os.path.abspath(os.getcwd() + '/' + args.target)
+        if args.target:
+            op = GEN
+            subdir = '/targets/'
+        elif args.checkers:
+            op = CHECK
+            subdir = '/checkers/'
+        else:
+            parse.error("At least one of --target and --checkers is required")
 
-        # check if there's a line that starts with +++ in the target
-        # if so, then the output file names are left to the target to decide
-        # also, if dest-file or dest-extension are supplied, then an error is generated.
-        plusplusplus = reduce(lambda acc, line: True if line.startswith('+++') else acc, open(args.target).read().splitlines(), False)
+        operators = args.checkers.split(',') if hasattr(args, 'checkers') and args.checkers else [args.target]
 
-        if plusplusplus and args.write_to_file != 'target':
-            parse.error('%s chooses the names of the files that it generates, you must set --write-to-file to "target"' % args.target)
+        for i in xrange(len(operators)):
+            if not '/' in operators[i]:
+                # if the target is not a path, it refer to a library included one
+                operators[i] = os.path.abspath(os.path.dirname(os.path.realpath(__file__)) + subdir + operators[i])
 
+            if not os.path.isabs(operators[i]):
+                operators[i] = os.path.abspath(os.getcwd() + '/' + operators[i])
 
-        if args.write_to_file != 'single' and (args.dest_file):
-            parse.error('--dest-file requires --write-to-file to be set to "single"')
+        if op == GEN:
+            # convert output to absolute path
+            if args.output is not None and not os.path.isabs(args.output):
+                args.output = os.path.abspath(os.getcwd() + '/' + args.output)
 
-        if args.write_to_file != 'model' and (args.dest_extension):
-            parse.error('--dest-extension requires --write-to-file to be set to "model"')
+            operator = operators[0]
+            
+            # check if there's a line that starts with +++ in the target
+            # if so, then the output file names are left to the target to decide
+            # also, if dest-file or dest-extension are supplied, then an error is generated.
+            plusplusplus = reduce(lambda acc, line: True if line.startswith('+++') else acc, open(operator).read().splitlines(), False)
+
+            if plusplusplus and args.write_to_file != 'target':
+                parse.error('%s chooses the names of the files that it generates, you must set --write-to-file to "target"' % operator)
+
+            if args.write_to_file != 'single' and (args.dest_file):
+                parse.error('--dest-file requires --write-to-file to be set to "single"')
+
+            if args.write_to_file != 'model' and (args.dest_extension):
+                parse.error('--dest-extension requires --write-to-file to be set to "model"')
+            
+        else:
+            if args.write_to_file or args.dest_extension:
+                parse.error('Checkers cannot write to files')
 
         inputs = []
 
@@ -74,9 +99,28 @@
                 inputs.append(os.path.abspath(os.getcwd() + '/' + fname))
             else:
                 inputs.append(fname)
+
         args.files = inputs
 
-        generated = XOSGenerator.generate(args)
+        if op==GEN:
+            generated = XOSProcessor.process(args, operators[0])
+            if not args.output and not args.write_to_file:
+                print generated
+        elif op==CHECK:
+            for o in operators:
+                verdict_str = XOSProcessor.process(args, o)
+                vlst = verdict_str.split('\n')
 
-        if not args.output and not args.write_to_file:
-            print generated
\ No newline at end of file
+                try:
+                    verdict = next(v for v in vlst if v.strip())
+                    status_code, status_string = verdict.split(' ', 1)
+                    status_code = int(status_code)
+                except:
+                    print "Checker %s returned mangled output" % o
+                    exit(1)
+
+                if status_code != 200:
+                    print '%s: %s - %s' % (o, status_code, status_string)
+                    exit(1)
+                else:
+                    print '%s: OK'%o