[RFC PATCH 1/7] scripts: convert checkdeclares.pl to Python

[Breno Rodrigues Alves <breno3011alves@gmail.com>]

Faithful re-implementation of checkdeclares.pl in Python 3
(stdlib only). Same output, same detection logic.

Tested byte-for-byte against the Perl version.

Signed-off-by: Breno Rodrigues Alves <breno3011alves@gmail.com>
---
 scripts/checkdeclares.py | 64 ++++++++++++++++++++++++++++++++++++++++
 1 file changed, 64 insertions(+)
 create mode 100755 scripts/checkdeclares.py

diff --git a/scripts/checkdeclares.py b/scripts/checkdeclares.py
new file mode 100755
index 000000000..32c826ac8
--- /dev/null
+++ b/scripts/checkdeclares.py
@@ -0,0 +1,64 @@
+#!/usr/bin/env python3
+# SPDX-License-Identifier: GPL-2.0
+#
+# checkdeclares: find struct declared more than once
+#
+# Copyright 2021 Wan Jiabing <wanjiabing@vivo.com>
+# Inspired by checkincludes.pl
+#
+# This script checks for duplicate struct declares.
+# Note that this will not take into consideration macros so
+# you should run this only if you know you do have real dups
+# and do not have them under #ifdef's.
+
+import re
+import sys
+
+RE_STRUCT_DECL = re.compile(r'^\s*struct\s*(\w*);$')
+
+
+def usage():
+    print('Usage: checkdeclares.py file1.h ...', file=sys.stderr)
+    print('Warns of struct declaration duplicates', file=sys.stderr)
+    sys.exit(1)
+
+
+def process_file(path):
+    """Return (dup_count, error_msg)."""
+    try:
+        with open(path, 'r') as f:
+            lines = f.readlines()
+    except OSError as e:
+        return 0, f"Cannot open {path}: {e}."
+
+    declared = {}
+    for line in lines:
+        m = RE_STRUCT_DECL.match(line)
+        if m:
+            declared[m.group(1)] = declared.get(m.group(1), 0) + 1
+
+    dups = 0
+    for name, n in declared.items():
+        if n > 1:
+            print(f"{path}: struct {name} is declared more than once.")
+            dups += 1
+    return dups, None
+
+
+def main(argv):
+    if not argv:
+        usage()
+    dup_counter = 0
+    for path in argv:
+        n, err = process_file(path)
+        if err:
+            print(err, file=sys.stderr)
+            sys.exit(1)
+        dup_counter += n
+    if dup_counter == 0:
+        print('No duplicate struct declares found.')
+    return 0
+
+
+if __name__ == '__main__':
+    sys.exit(main(sys.argv[1:]))
\ No newline at end of file
-- 
2.43.0