Add a simple script to remove boards

This script attempts to create a git commit which removes a single board.
It is quite fallible and everything it does needs checking. But it can
help speed up the process.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Chris Packham <judge.packham@gmail.com>

diff --git a/tools/rmboard.py b/tools/rmboard.py
new file mode 100755 (executable)
index 0000000..df4f04b
--- /dev/null
+++ b/tools/rmboard.py
@@ -0,0 +1,150 @@
+#! /usr/bin/python
+# SPDX-License-Identifier: GPL-2.0+
+# Copyright 2019 Google LLC
+#
+
+"""
+Script to remove boards
+
+Usage:
+   rmboard.py <board_name>...
+
+A single commit is created for each board removed.
+
+Some boards may depend on files provided by another and this will cause
+problems, generally the removal of files which should not be removed.
+
+This script works by:
+    - Looking through the MAINTAINERS files which mention a board to find out
+        what files the board uses
+    - Looking through the Kconfig files which mention a board to find one that
+        needs to have material removed
+
+Search for ## to update the commit message manually.
+"""
+
+from __future__ import print_function
+
+import glob
+import os
+import re
+import sys
+
+# Bring in the patman libraries
+our_path = os.path.dirname(os.path.realpath(__file__))
+sys.path.append(os.path.join(our_path, '../tools/patman'))
+
+import command
+
+def rm_kconfig_include(path):
+    """Remove a path from Kconfig files
+
+    This function finds the given path in a 'source' statement in a Kconfig
+    file and removes that line from the file. This is needed because the path
+    is going to be removed, so any reference to it will cause a problem with
+    Kconfig parsing.
+
+    The changes are made locally and then added to the git staging area.
+
+    Args:
+        path: Path to search for and remove
+    """
+    cmd = ['git', 'grep', path]
+    stdout = command.RunPipe([cmd], capture=True, raise_on_error=False).stdout
+    if not stdout:
+        return
+    fname = stdout.split(':')[0]
+
+    print("Fixing up '%s' to remove reference to '%s'" % (fname, path))
+    cmd = ['sed', '-i', '\|%s|d' % path, fname]
+    stdout = command.RunPipe([cmd], capture=True).stdout
+
+    cmd = ['git', 'add', fname]
+    stdout = command.RunPipe([cmd], capture=True).stdout
+
+def rm_board(board):
+    """Create a commit which removes a single board
+
+    This looks up the MAINTAINERS file to file files that need to be removed,
+    then removes pieces from the Kconfig files that mention the board.
+
+
+    Args:
+        board: Board name to remove
+    """
+
+    # Find all MAINTAINERS and Kconfig files which mention the board
+    cmd = ['git', 'grep', '-l', board]
+    stdout = command.RunPipe([cmd], capture=True).stdout
+    maintain = []
+    kconfig = []
+    for line in stdout.splitlines():
+        line = line.strip()
+        if 'MAINTAINERS' in line:
+            if line not in maintain:
+                maintain.append(line)
+        elif 'Kconfig' in line:
+            kconfig.append(line)
+    paths = []
+    cc = []
+
+    # Look through the MAINTAINERS file to find things to remove
+    for fname in maintain:
+        with open(fname) as fd:
+            for line in fd:
+                line = line.strip()
+                fields = re.split('[ \t]', line, 1)
+                if len(fields) == 2:
+                    if fields[0] == 'M:':
+                        cc.append(fields[1])
+                    elif fields[0] == 'F:':
+                        paths.append(fields[1].strip())
+
+    # Expand any wildcards in the MAINTAINERS file
+    real = []
+    for path in paths:
+        if path[-1] == '/':
+            path = path[:-1]
+        if '*' in path:
+            globbed = glob.glob(path)
+            print("Expanded '%s' to '%s'" % (path, globbed))
+            real += globbed
+        else:
+            real.append(path)
+
+    # Search for Kconfig files in the resulting list. Remove any 'source' lines
+    # which reference Kconfig files we want to remove
+    for path in real:
+        cmd = ['find', path]
+        stdout = (command.RunPipe([cmd], capture=True, raise_on_error=False).
+                  stdout)
+        for fname in stdout.splitlines():
+            if fname.endswith('Kconfig'):
+                rm_kconfig_include(fname)
+
+    # Remove unwanted files
+    cmd = ['git', 'rm', '-r'] + real
+    stdout = command.RunPipe([cmd], capture=True).stdout
+
+    ## Change the messages as needed
+    msg = '''arm: Remove %s board
+
+This board has not been converted to CONFIG_DM_MMC by the deadline.
+Remove it.
+
+''' % board
+    for name in cc:
+        msg += 'Patch-cc: %s\n' % name
+
+    # Create the commit
+    cmd = ['git', 'commit', '-s', '-m', msg]
+    stdout = command.RunPipe([cmd], capture=True).stdout
+
+    # Check if the board is mentioned anywhere else. The user will need to deal
+    # with this
+    cmd = ['git', 'grep', '-il', board]
+    print(command.RunPipe([cmd], capture=True, raise_on_error=False).stdout)
+    print(' '.join(cmd))
+
+for board in sys.argv[1:]:
+    rm_board(board)