[analyzer] exploded-graph-rewriter: NFC: Add more comments.

llvm-svn: 364991

Author: haoNoQ

clang/utils/analyzer/exploded-graph-rewriter.py

@@ -19,6 +19,11 @@
 import re
 
 
+#===-----------------------------------------------------------------------===#
+# These data structures represent a deserialized ExplodedGraph.
+#===-----------------------------------------------------------------------===#
+
+
 # A helper function for finding the difference between two dictionaries.
 def diff_dicts(curr, prev):
     removed = [k for k in prev if k not in curr or curr[k] != prev[k]]
@@ -368,6 +373,12 @@ def add_raw_line(self, raw_line):
         logging.debug('Skipping.')
 
 
+#===-----------------------------------------------------------------------===#
+# Visitors traverse a deserialized ExplodedGraph and do different things
+# with every node and edge.
+#===-----------------------------------------------------------------------===#
+
+
 # A visitor that dumps the ExplodedGraph into a DOT file with fancy HTML-based
 # syntax highlighing.
 class DotDumpVisitor(object):
@@ -775,11 +786,17 @@ def visit_end_of_graph(self):
         self._dump_raw('}\n')
 
 
+#===-----------------------------------------------------------------------===#
+# Explorers know how to traverse the ExplodedGraph in a certain order.
+# They would invoke a Visitor on every node or edge they encounter.
+#===-----------------------------------------------------------------------===#
+
+
 # A class that encapsulates traversal of the ExplodedGraph. Different explorer
 # kinds could potentially traverse specific sub-graphs.
-class Explorer(object):
+class BasicExplorer(object):
     def __init__(self):
-        super(Explorer, self).__init__()
+        super(BasicExplorer, self).__init__()
 
     def explore(self, graph, visitor):
         visitor.visit_begin_graph(graph)
@@ -792,6 +809,11 @@ def explore(self, graph, visitor):
         visitor.visit_end_of_graph()
 
 
+#===-----------------------------------------------------------------------===#
+# The entry point to the script.
+#===-----------------------------------------------------------------------===#
+
+
 def main():
     parser = argparse.ArgumentParser()
     parser.add_argument('filename', type=str)
@@ -814,7 +836,7 @@ def main():
             raw_line = raw_line.strip()
             graph.add_raw_line(raw_line)
 
-    explorer = Explorer()
+    explorer = BasicExplorer()
     visitor = DotDumpVisitor(args.diff, args.dark)
     explorer.explore(graph, visitor)