Add command line argument parser

Signed-off-by: Juraj Oravec <jurajoravec@mailo.com>

main.py

@@ -1,15 +1,18 @@
 #!/bin/python
 
+import os
 import sys
 import math
+import argparse
 from bear import formats
 from elftools.dwarf.locationlists import LocationParser, LocationExpr
 from elftools.dwarf.dwarf_expr import DWARFExprParser, DWARFExprOp, DW_OP_opcode2name
 from bear.dwarfone import DWARFExprParserV1
 
 
+SCRIPT_VERSION = '0.1.0'
 configuration = {
-    "include_file_name": False,
+    'include_file_name': False,
 }
 
 
@@ -43,7 +46,7 @@ def load_children(parent_die):
             # QMessageBox(QMessageBox.Icon.Warning, "DWARF Explorer",
             #     "This executable file is corrupt or incompatible with the current version of DWARF Explorer. Please consider creating a new issue at https://github.com/sevaa/dwex/, and share this file with the tech support.",
             #     QMessageBox.StandardButton.Ok, QApplication.instance().win).show()
-            print("This executable file is corrupt or incompatible with the current version of Bear.")
+            print("This executable file is corrupt or incompatible.")
             parent_die._children = []
 
 
@@ -69,7 +72,8 @@ class Bear():
                 cu._lineprogram = None
                 cu._exprparser = None
                 return cu
-            di._unsorted_CUs = [decorate_cu(cu, i) for (i, cu) in enumerate(di.iter_CUs())]  # We'll need them first thing, might as well load here
+            # We'll need them first thing, might as well load here
+            di._unsorted_CUs = [decorate_cu(cu, i) for (i, cu) in enumerate(di.iter_CUs())]
             if not len(di._unsorted_CUs):
                 return None  # Weird, but saw it once - debug sections present, but no CUs
             # For quick CU search by offset within the info section, regardless of sorting
@@ -157,7 +161,8 @@ class Bear():
         if die_type.tag == 'DW_TAG_base_type':
             real_type_name = safe_DIE_name(die_type, '?')
             if real_type_name != '?' and real_type_name != entry['type']:
-                entry['type'] = '{name} ({real})'.format(name=entry['type'], real=safe_DIE_name(die_type, '?'))
+                entry['type'] = '{name} ({real})'.format(name=entry['type'],
+                                                         real=safe_DIE_name(die_type, '?'))
         elif die_type.tag == "DW_TAG_structure_type":
             load_children(die_type)
             child_dies = []
@@ -214,14 +219,16 @@ class Bear():
         for CU in self.myVariables:
             for child in CU['children']:
                 if configuration["include_file_name"]:
-                    self.pettanko(child, CU['name'])
+                    self.pettanko(child, CU['name'], ":")
                 else:
                     self.pettanko(child)
 
-    def pettanko(self, entry : dict, a_parent_name : str = ""):
+    def pettanko(self, entry : dict, a_parent_name : str = '', separator : str = '.'):
         flat_entry = dict()
         if a_parent_name:
-            flat_entry['name'] = '{0}.{1}'.format(a_parent_name, entry['name'])
+            flat_entry['name'] = '{parent}{separator}{child}'.format(parent=a_parent_name,
+                                                                     separator=separator,
+                                                                     child=entry['name'])
         else:
             flat_entry['name'] = entry['name']
 
@@ -245,7 +252,7 @@ class Bear():
         if 'number_of_elements' in entry:
             for index in range(0, entry['number_of_elements']):
                 kid = flat_entry.copy()
-                kid['name'] = '{0}[{1}]'.format(flat_entry['name'], index)
+                kid['name'] = '{name}[{index}]'.format(name=flat_entry['name'], index=index)
                 kid['address'] = hex(int(flat_entry['address'], 16) + entry['size_byte'] * index)
 
                 self.pettanko(kid)
@@ -258,7 +265,8 @@ class Bear():
 
     def pretty_print(self):
         for entry in self.flat_list:
-            print('{address}\t{variable_name}'.format(address=entry['address'], variable_name=entry['name']))
+            print('{address}\t{variable_name}'.format(address=entry['address'],
+                                                      variable_name=entry['name']))
 
     def parse_location(self, die, attr):
         di = die.dwarfinfo
@@ -287,7 +295,27 @@ def main():
     from bear.patch import monkeypatch
     monkeypatch()
 
-    bear = Bear("/home/juraj/projects/Playground_C/build/playground_c")
+    parser = argparse.ArgumentParser(
+        description='Expands symbols (global variables) types.',
+        epilog='Data displayed by this script are informative only!'
+    )
+    parser.add_argument('elf_file', metavar='file', type=str, nargs='?',
+                        help='ELF file to try to extract symbols')
+    parser.add_argument('--include-file-name', dest='include_file_name', action='store_true',
+                        help='Display filename at the beginning')
+    parser.add_argument('--version', action='version',
+                        version='%(prog)s {version}'.format(version=SCRIPT_VERSION))
+
+    args = parser.parse_args()
+
+    from pprint import pprint
+    configuration['include_file_name'] = args.include_file_name
+
+    if not os.path.exists(args.elf_file):
+        eprint('File {elf_file} does not exist!'.format(elf_file=args.elf_file))
+        exit(1)
+
+    bear = Bear(args.elf_file)
     bear.flatten_type()
     bear.pretty_print()