Update the syntax in reduce.py (#6843)

Author: swasti16

tools/reduce.py

@@ -1,24 +1,40 @@
+"""
+usage: reduce.py [-h] -exe EXE -exe_args EXE_ARGS -expected EXPECTED -file FILE [-segfault]
+
+options:
+  -h, --help            show this help message and exit
+  -exe EXE, --exe EXE   cppcheck executable
+  -exe_args EXE_ARGS, --exe_args EXE_ARGS
+                        cppcheck executable commands
+  -expected EXPECTED, --expected EXPECTED
+                        expected text output
+  -file FILE, --file FILE
+                        source file
+  -segfault, --segfault
+"""
+
 #!/usr/bin/env python3
 import subprocess
 import sys
 import time
+import argparse
 
 
 class Reduce:
     def __init__(self, cmd, expected, file, segfault=None):
-        if cmd is None:
+        if not "".join(cmd):
             raise RuntimeError('Abort: No --cmd')
 
-        if not segfault and expected is None:
+        if not segfault and not expected:
             raise RuntimeError('Abort: No --expected')
 
-        if file is None:
+        if not file:
             raise RuntimeError('Abort: No --file')
 
         # need to add '--error-exitcode=0' so detected issues will not be interpreted as a crash
         if segfault and '--error-exitcode=0' not in cmd:
             print("Adding '--error-exitcode=0' to --cmd")
-            self.__cmd = cmd + ' --error-exitcode=0'
+            self.__cmd = cmd + ['--error-exitcode=0']
         else:
             self.__cmd = cmd
         self.__expected = expected
@@ -30,7 +46,7 @@ def __init__(self, cmd, expected, file, segfault=None):
         self.__elapsed_time = None
 
     def print_info(self):
-        print('CMD=' + self.__cmd)
+        print('CMD=', " ".join(self.__cmd))
         if self.__segfault:
             print('EXPECTED=SEGFAULT')
         else:
@@ -46,7 +62,7 @@ def runtool(self, filedata=None):
         timeout = None
         if self.__elapsed_time:
             timeout = self.__elapsed_time * 2
-        p = subprocess.Popen(self.__cmd.split(), stdout=subprocess.PIPE, stderr=subprocess.PIPE, universal_newlines=True)
+        p = subprocess.Popen(self.__cmd, stdout=subprocess.PIPE, stderr=subprocess.PIPE, universal_newlines=True)
         try:
             comm = self.__communicate(p, timeout=timeout)
         except TimeoutExpired:
@@ -268,31 +284,27 @@ def main():
     # TODO: add --hang option to detect code which impacts the analysis time
     def show_syntax():
         print('Syntax:')
-        print('  reduce.py --cmd=<full command> --expected=<expected text output> --file=<source file> [--segfault]')
+        print('  reduce.py --exe <cppcheck executable> --exe_args <full command> --expected <expected text output> --file <source file> [--segfault]')
         print('')
         print("Example. source file = foo/bar.c")
         print(
-            "  reduce.py --cmd='./cppcheck --enable=style foo/bar.c' --expected=\"Variable 'x' is reassigned\" --file=foo/bar.c")
+            '  reduce.py --exe ./cppcheck --exe_args " --enable=style" --expected "Variable \'x\' is reassigned" --file foo/bar.c')
         sys.exit(1)
 
     if len(sys.argv) == 1:
         show_syntax()
-
-    arg_cmd = None
-    arg_expected = None
-    arg_file = None
-    arg_segfault = False
-
-    for arg in sys.argv[1:]:
-        if arg.startswith('--cmd='):
-            arg_cmd = arg[arg.find('=') + 1:]
-        elif arg.startswith('--expected='):
-            arg_expected = arg[arg.find('=') + 1:]
-        elif arg.startswith('--file='):
-            arg_file = arg[arg.find('=') + 1:]
-        elif arg == '--segfault':
-            arg_segfault = True
-
+    parser = argparse.ArgumentParser()
+    parser.add_argument('-exe', '--exe', required=True, help="cppcheck executable")
+    parser.add_argument('-exe_args', '--exe_args', required=False, default="", help="cppcheck executable commands")
+    parser.add_argument('-expected', '--expected', required=True, help="expected text output")
+    parser.add_argument('-file', '--file', required=True, help="source file")
+    parser.add_argument('-segfault', '--segfault', required=False, action='store_true')
+    args = parser.parse_args()
+
+    arg_file = args.file
+    arg_cmd = [args.exe] + args.exe_args.split() + [arg_file]
+    arg_expected = args.expected
+    arg_segfault = args.segfault
     try:
         reduce = Reduce(arg_cmd, arg_expected, arg_file, arg_segfault)
     except RuntimeError as e: