Fix latest pylint issues

bin/verilator_profcfunc

@@ -135,8 +135,7 @@ def profcfunc(filename):
 
     design_width = 1
     for func, func_item in vfuncs.items():
-        if design_width < len(func_item['design']):
-            design_width = len(func_item['design'])
+        design_width = max(design_width, len(func_item['design']))
 
     print("Verilog code profile:")
     print("   These are split into three categories:")

src/astgen

@@ -852,6 +852,10 @@ def write_type_tests(prefix, nodeList):
             base = "DfgVertex"
             variable = "vtxp"
             enum = "VDfgType"
+        else:
+            base = None
+            variable = None
+            enum = None
         for node in nodeList:
             fh.write(
                 "template<> inline bool {b}::privateTypeTest<{p}{n}>(const {b}* {v}) {{ ".format(

src/bisonpre

@@ -11,11 +11,11 @@ import sys
 
 ######################################################################
 
+Bison_Version = None
 
 def process():
     unlink_outputs()
 
-    bison_version_check()
     supports_report = Bison_Version >= 2.3
     # supports_counter_examples = Bison_Version >= 3.8
 
@@ -93,9 +93,7 @@ def bison_version_check():
         if v < 1.875:
             sys.exit("bisonpre: %Error: '" + Args.yacc + "' is version " + v +
                      "; version 1.875 or newer is required\n")
-        global Bison_Version  # pylint: disable=global-variable-undefined
-        Bison_Version = v
-        return
+        return v
 
     sys.exit("bisonpre: %Error: '" + Args.yacc + "' is not installed, or not working\n")
 
@@ -515,6 +513,8 @@ parser.add_argument('input', help='Passed to bison. Input grammar file.')
 
 Args = parser.parse_args()
 
+Bison_Version = bison_version_check()
+
 process()
 
 ######################################################################