diff --git a/analyze.py b/analyze.py
index 263d64d..ddf7e5e 100644
--- a/analyze.py
+++ b/analyze.py
@@ -1,7 +1,8 @@
 from __future__ import print_function
 import argparse
-import sys
+import os,sys,io
 from pycparser import parse_file, c_ast, CParser
+from pcpp import Preprocessor
 import graphviz as gv
 
 from modelbuilder import *
@@ -26,15 +27,27 @@ if __name__ == "__main__":
         #read whole file to a string
         source = f.read()
     
+    p = Preprocessor()
+    p.add_path('/usr/lib/gcc/x86_64-linux-gnu/12/include/')
+
+    p.parse(source)
+    oh = io.StringIO()
+    p.write(oh)
+    prep_source = oh.getvalue()
+    
+    #print(prep_source)
+    #exit()
+
     parser = CParser()
-    ast = parser.parse(comment_remover(source))
+    ast = parser.parse(prep_source)
     #ast = parse_file(args.filename, use_cpp=False)
     
     assign_table = []
     state_enums = []
     func_table = {}
     enum_table = {}
-
+    state_asmts = []
+    
     fdv = FuncDefVisitor()
     fdv.visit(ast)
     func_table = fdv.func_table
@@ -43,7 +56,8 @@ if __name__ == "__main__":
     etv.visit(ast)
     enum_table = etv.enums
     
-    state_asmts = []
+    if not(args.func in func_table):
+        raise Exception(f"Function name '{args.func}' not found!")
 
     if args.enum in enum_table:
         ev = EnumVisitor()
diff --git a/requirements.txt b/requirements.txt
new file mode 100644
index 0000000..8d35481
--- /dev/null
+++ b/requirements.txt
@@ -0,0 +1,3 @@
+pycparser
+graphviz
+pcpp>=1.30