RFC: tools: Add a camel-case conversion script

This is only for posterity, since once the conversion is done, the script
is of no use.

Signed-off-by: Simon Glass <sjg@chromium.org>

diff --git a/scripts/style.py b/scripts/style.py
new file mode 100755 (executable)
index 0000000..7b73b00
--- /dev/null
+++ b/scripts/style.py
@@ -0,0 +1,180 @@
+#!/usr/bin/env python3
+# SPDX-License-Identifier: GPL-2.0+
+#
+# Copyright 2021 Google LLC
+#
+
+"""Changes the functions and class methods in a file to use snake case, updating
+other tools which use them"""
+
+from argparse import ArgumentParser
+import glob
+import os
+import re
+import subprocess
+
+import camel_case
+
+# Exclude functions with these names
+EXCLUDE_NAMES = set(['setUp', 'tearDown', 'setUpClass', 'tearDownClass'])
+
+# Find function definitions in a file
+RE_FUNC = re.compile(r' *def (\w+)\(')
+
+# Where to find files that might call the file being converted
+FILES_GLOB = 'tools/**/*.py'
+
+def collect_funcs(fname):
+    """Collect a list of functions in a file
+
+    Args:
+        fname (str): Filename to read
+
+    Returns:
+        tuple:
+            str: contents of file
+            list of str: List of function names
+    """
+    with open(fname, encoding='utf-8') as inf:
+        data = inf.read()
+        funcs = RE_FUNC.findall(data)
+    return data, funcs
+
+def get_module_name(fname):
+    """Convert a filename to a module name
+
+    Args:
+        fname (str): Filename to convert, e.g. 'tools/patman/command.py'
+
+    Returns:
+        tuple:
+            str: Full module name, e.g. 'patman.command'
+            str: Leaf module name, e.g. 'command'
+            str: Program name, e.g. 'patman'
+    """
+    parts = os.path.splitext(fname)[0].split('/')[1:]
+    module_name = '.'.join(parts)
+    return module_name, parts[-1], parts[0]
+
+def process_caller(data, conv, module_name, leaf):
+    """Process a file that might call another module
+
+    This converts all the camel-case references in the provided file contents
+    with the corresponding snake-case references.
+
+    Args:
+        data (str): Contents of file to convert
+        conv (dict): Identifies to convert
+            key: Current name in camel case, e.g. 'DoIt'
+            value: New name in snake case, e.g. 'do_it'
+        module_name: Name of module as referenced by the file, e.g.
+            'patman.command'
+        leaf: Leaf module name, e.g. 'command'
+
+    Returns:
+        str: New file contents, or None if it was not modified
+    """
+    total = 0
+
+    # Update any simple functions calls into the module
+    for name, new_name in conv.items():
+        newdata, count = re.subn(fr'{leaf}.{name}\(',
+                                 f'{leaf}.{new_name}(', data)
+        total += count
+        data = newdata
+
+    # Deal with files that import symbols individually
+    imports = re.findall(fr'from {module_name} import (.*)\n', data)
+    for item in imports:
+        #print('item', item)
+        names = [n.strip() for n in item.split(',')]
+        new_names = [conv.get(n) or n for n in names]
+        new_line = f"from {module_name} import {', '.join(new_names)}\n"
+        data = re.sub(fr'from {module_name} import (.*)\n', new_line, data)
+        for name in names:
+            new_name = conv.get(name)
+            if new_name:
+                newdata = re.sub(fr'\b{name}\(', f'{new_name}(', data)
+                data = newdata
+
+    # Deal with mocks like:
+    # unittest.mock.patch.object(module, 'Function', ...
+    for name, new_name in conv.items():
+        newdata, count = re.subn(fr"{leaf}, '{name}'",
+                                 f"{leaf}, '{new_name}'", data)
+        total += count
+        data = newdata
+
+    if total or imports:
+        return data
+    return None
+
+def process_file(srcfile, do_write, commit):
+    """Process a file to rename its camel-case functions
+
+    This renames the class methods and functions in a file so that they use
+    snake case. Then it updates other modules that call those functions.
+
+    Args:
+        srcfile (str): Filename to process
+        do_write (bool): True to write back to files, False to do a dry run
+        commit (bool): True to create a commit with the changes
+    """
+    data, funcs = collect_funcs(srcfile)
+    module_name, leaf, prog = get_module_name(srcfile)
+    #print('module_name', module_name)
+    #print(len(funcs))
+    #print(funcs[0])
+    conv = {}
+    for name in funcs:
+        if name not in EXCLUDE_NAMES:
+            conv[name] = camel_case.to_snake(name)
+
+    # Convert name to new_name in the file
+    for name, new_name in conv.items():
+        #print(name, new_name)
+        # Don't match if it is preceded by a '.', since that indicates that
+        # it is calling this same function name but in a different module
+        newdata = re.sub(fr'(?<!\.){name}\(', f'{new_name}(', data)
+        data = newdata
+
+        # But do allow self.xxx
+        newdata = re.sub(fr'self.{name}\(', f'self.{new_name}(', data)
+        data = newdata
+    if do_write:
+        with open(srcfile, 'w', encoding='utf-8') as out:
+            out.write(data)
+
+    # Now find all files which use these functions and update them
+    for fname in glob.glob(FILES_GLOB, recursive=True):
+        with open(fname, encoding='utf-8') as inf:
+            data = inf.read()
+        newdata = process_caller(fname, conv, module_name, leaf)
+        if do_write and newdata:
+            with open(fname, 'w', encoding='utf-8') as out:
+                out.write(newdata)
+
+    if commit:
+        subprocess.call(['git', 'add', '-u'])
+        subprocess.call([
+            'git', 'commit', '-s', '-m',
+            f'''{prog}: Convert camel case in {os.path.basename(srcfile)}
+
+Convert this file to snake case and update all files which use it.
+'''])
+
+
+def main():
+    """Main program"""
+    epilog = 'Convert camel case function names to snake in a file and callers'
+    parser = ArgumentParser(epilog=epilog)
+    parser.add_argument('-c', '--commit', action='store_true',
+                        help='Add a commit with the changes')
+    parser.add_argument('-n', '--dry_run', action='store_true',
+                        help='Dry run, do not write back to files')
+    parser.add_argument('-s', '--srcfile', type=str, required=True, help='Filename to convert')
+    args = parser.parse_args()
+    process_file(args.srcfile, not args.dry_run, args.commit)
+
+if __name__ == '__main__':
+    main()