1 files changed, 123 insertions, 0 deletions
diff --git a/zephyr/zmake/zmake/generate_readme.py b/zephyr/zmake/zmake/generate_readme.py
new file mode 100644
index 0000000000..d21fd19f7c
--- /dev/null
+++ b/zephyr/zmake/zmake/generate_readme.py
@@ -0,0 +1,123 @@
+# Copyright 2022 The Chromium OS Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+"""Code for auto-generating README.md."""
+
+import argparse
+import io
+
+
+class MarkdownHelpFormatter(argparse.HelpFormatter):
+    """Callbacks to format help output as Markdown."""
+
+    def __init__(self, prog):
+        self._prog = prog
+        self._section_title = None
+        self._section_contents = []
+        self._paragraphs = []
+        super().__init__(prog=prog)
+
+    def add_text(self, text):
+        if text and text is not argparse.SUPPRESS:
+            lst = self._paragraphs
+            if self._section_title:
+                lst = self._section_contents
+            lst.append(text)
+
+    def start_section(self, title):
+        self._section_title = title.title()
+        self._section_contents = []
+
+    def end_section(self):
+        if self._section_contents:
+            self._paragraphs.append(f"#### {self._section_title}")
+            self._paragraphs.extend(self._section_contents)
+        self._section_title = None
+
+    def add_usage(self, usage, actions, groups):
+        if not usage:
+            usage = self._prog
+        self.add_text(
+            f"**Usage:** `{usage} {self._format_actions_usage(actions, groups)}`"
+        )
+
+    def add_arguments(self, actions):
+        def _get_metavar(action):
+            return action.metavar or action.dest
+
+        def _format_invocation(action):
+            if action.option_strings:
+                parts = []
+                for option_string in action.option_strings:
+                    if action.nargs == 0:
+                        parts.append(option_string)
+                    else:
+                        parts.append(f"{option_string} {_get_metavar(action).upper()}")
+                return ", ".join(f"`{part}`" for part in parts)
+            else:
+                return f"`{_get_metavar(action)}`"
+
+        def _get_table_line(action):
+            return f"| {_format_invocation(action)} | {action.help} |"
+
+        table_lines = [
+            "|   |   |",
+            "|---|---|",
+            *(
+                _get_table_line(action)
+                for action in actions
+                if action.help is not argparse.SUPPRESS
+            ),
+        ]
+
+        # Don't want a table with no rows.
+        if len(table_lines) > 2:
+            self.add_text("\n".join(table_lines))
+
+    def format_help(self):
+        return "\n\n".join(self._paragraphs)
+
+
+def generate_readme():
+    """Generate the README.md file.
+
+    Returns:
+        A string with the README contents.
+    """
+    # Deferred import position to avoid circular dependency.
+    # Normally, this would not be required, since we don't use from
+    # imports.  But runpy's import machinery essentially does the
+    # equivalent of a from import on __main__.py.
+    import zmake.__main__
+
+    output = io.StringIO()
+    parser, sub_action = zmake.__main__.get_argparser()
+
+    def _append(*args, **kwargs):
+        kwargs.setdefault("file", output)
+        print(*args, **kwargs)
+
+    def _append_argparse_help(parser):
+        parser.formatter_class = MarkdownHelpFormatter
+        _append(parser.format_help())
+
+    _append("# Zmake")
+    _append()
+    _append('<!-- Auto-generated contents!  Run "zmake generate-readme" to update. -->')
+    _append()
+    _append("[TOC]")
+    _append()
+    _append("## Usage")
+    _append()
+    _append_argparse_help(parser)
+    _append()
+    _append("## Subcommands")
+
+    for sub_name, sub_parser in sub_action.choices.items():
+        _append()
+        _append(f"### zmake {sub_name}")
+        _append()
+        _append_argparse_help(sub_parser)
+
+    return output.getvalue()