scripts/get_abi.py: add a Python tool to generate ReST output

The get_abi.pl script is requiring some care, but it seems that
the number of changes on it since when I originally wrote it
was not too high.

Maintaining perl scripts without using classes requires a higher
efforted than on python, due to global variables management.
Also, it sounds easier to find python developer those days than
perl ones.

As a plus, using a Python class to handle ABI allows a better
integration with Sphinx extensions, allowing, for instance,
to let automarkup to generate cross-references for ABI
symbols.

With that in mind, rewrite the core of get_abi.pl in Python,
using classes, to help producing documentation. This will
allow a better integration in the future with the Sphinx
ABI extension.

The algorithms used there are the same as the ones in Perl,
with a couple of cleanups to remove redundant variables and
to help with cross-reference generation. While doing that,
remove some code that were important in the past, where
ABI files weren't using ReST format.

Some minor improvements were added like using a fixed seed
when generating ABI keys for duplicated names, making its
results reproductible.

The end script is a little bit faster than the original one
(tested on a machine with ssd disks). That's probably because
we're now using only pre-compiled regular expressions, and it
is using string replacement methods instead of regex where
possible.

The new version is a little bit more conservative when
converting text to cross-references to avoid adding them into
literal blocks.

To ensure that the ReST output is parsing all variables
and files properly, the end result was compared using diff
with the one produced by the perl script and showed no regressions.
There are minor improvements at the results, as it now
properly groups What on some special cases. It also better
escape some XREF names.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Link: https://lore.kernel.org/r/71a894211a8b69664711144d9c4f8a0e73d1ae3c.1739182025.git.mchehab+huawei@kernel.org

1 files changed, 118 insertions, 0 deletions

diff --git a/scripts/get_abi.py b/scripts/get_abi.py
new file mode 100755
index 000000000000..bb17c54feeff
--- /dev/null
+++ b/scripts/get_abi.py
@@ -0,0 +1,118 @@
+#!/usr/bin/env python3
+# pylint: disable=R0903
+# Copyright(c) 2025: Mauro Carvalho Chehab <mchehab@kernel.org>.
+# SPDX-License-Identifier: GPL-2.0
+
+"""
+Parse ABI documentation and produce results from it.
+"""
+
+import argparse
+import logging
+import os
+import sys
+
+# Import Python modules
+
+LIB_DIR = "lib/abi"
+SRC_DIR = os.path.dirname(os.path.realpath(__file__))
+
+sys.path.insert(0, os.path.join(SRC_DIR, LIB_DIR))
+
+from abi_parser import AbiParser                # pylint: disable=C0413
+from helpers import ABI_DIR, DEBUG_HELP         # pylint: disable=C0413
+
+# Command line classes
+
+
+REST_DESC = """
+Produce output in ReST format.
+
+The output is done on two sections:
+
+- Symbols: show all parsed symbols in alphabetic order;
+- Files: cross reference the content of each file with the symbols on it.
+"""
+
+class AbiRest:
+    """Initialize an argparse subparser for rest output"""
+
+    def __init__(self, subparsers):
+        """Initialize argparse subparsers"""
+
+        parser = subparsers.add_parser("rest",
+                                       formatter_class=argparse.RawTextHelpFormatter,
+                                       description=REST_DESC)
+
+        parser.add_argument("--enable-lineno",  action="store_true",
+                            help="enable lineno")
+        parser.add_argument("--raw", action="store_true",
+                            help="output text as contained in the ABI files. "
+                                 "It not used, output will contain dynamically"
+                                 " generated cross references when possible.")
+        parser.add_argument("--no-file", action="store_true",
+                            help="Don't the files section")
+        parser.add_argument("--show-hints", help="Show-hints")
+
+        parser.set_defaults(func=self.run)
+
+    def run(self, args):
+        """Run subparser"""
+
+        parser = AbiParser(args.dir, debug=args.debug)
+        parser.parse_abi()
+        parser.check_issues()
+        parser.print_data(args.enable_lineno, args.raw, not args.no_file)
+
+
+class AbiValidate:
+    """Initialize an argparse subparser for ABI validation"""
+
+    def __init__(self, subparsers):
+        """Initialize argparse subparsers"""
+
+        parser = subparsers.add_parser("validate",
+                                       formatter_class=argparse.ArgumentDefaultsHelpFormatter,
+                                       description="list events")
+
+        parser.set_defaults(func=self.run)
+
+    def run(self, args):
+        """Run subparser"""
+
+        parser = AbiParser(args.dir, debug=args.debug)
+        parser.parse_abi()
+        parser.check_issues()
+
+
+def main():
+    """Main program"""
+
+    parser = argparse.ArgumentParser(formatter_class=argparse.RawTextHelpFormatter)
+
+    parser.add_argument("-d", "--debug", type=int, default=0, help="debug level")
+    parser.add_argument("-D", "--dir", default=ABI_DIR, help=DEBUG_HELP)
+
+    subparsers = parser.add_subparsers()
+
+    AbiRest(subparsers)
+    AbiValidate(subparsers)
+
+    args = parser.parse_args()
+
+    if args.debug:
+        level = logging.DEBUG
+    else:
+        level = logging.INFO
+
+    logging.basicConfig(level=level, format="[%(levelname)s] %(message)s")
+
+    if "func" in args:
+        args.func(args)
+    else:
+        sys.exit(f"Please specify a valid command for {sys.argv[0]}")
+
+
+# Call main method
+if __name__ == "__main__":
+    main()