zephyr: copy zmake to platform/ec

This copies zmake into platform/ec/zephyr/zmake, as explained in
go/zephyr-fewer-repos.

Follow-on CLs will be submitted to:
- Update the chromeos-base/zephyr-build-tools ebuild to reference this
  directory instead of the one in zephyr-chrome.
- Remove the copy of zmake in zephyr-chrome.

Those interested in the git history of this code prior to it being
moved to platform/ec can find it here:
  https://chromium.googlesource.com/chromiumos/platform/zephyr-chrome/+log/bacea2e3e62c41000e5bdb4ed6433f24386d14bf/util

BUG=b:177003034
BRANCH=none
TEST=emerge with new path (requires follow-on CL)

Signed-off-by: Jack Rosenthal <jrosenth@chromium.org>
Change-Id: Ia957b3e35ce3b732968ebf8df603ef13298cc6b3
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/2618501
Reviewed-by: Yuval Peress <peress@chromium.org>

1 files changed, 147 insertions, 0 deletions

diff --git a/zephyr/zmake/zmake/util.py b/zephyr/zmake/zmake/util.py
new file mode 100644
index 0000000000..fc81176b6c
--- /dev/null
+++ b/zephyr/zmake/zmake/util.py
@@ -0,0 +1,147 @@
+# Copyright 2020 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.
+"""Common miscellaneous utility functions for zmake."""
+
+import os
+import pathlib
+import re
+import shlex
+
+
+def locate_cros_checkout():
+    """Find the path to the ChromiumOS checkout.
+
+    Returns:
+        The first directory found with a .repo directory in it,
+        starting by checking the CROS_WORKON_SRCROOT environment
+        variable, then scanning upwards from the current directory,
+        and finally from a known set of common paths.
+    """
+    def propose_checkouts():
+        yield os.getenv('CROS_WORKON_SRCROOT')
+
+        path = pathlib.Path.cwd()
+        while path.resolve() != pathlib.Path('/'):
+            yield path
+            path = path / '..'
+
+        yield '/mnt/host/source'
+        yield pathlib.Path.home() / 'trunk'
+        yield pathlib.Path.home() / 'chromiumos'
+
+    for path in propose_checkouts():
+        if not path:
+            continue
+        path = pathlib.Path(path)
+        if (path / '.repo').is_dir():
+            return path.resolve()
+
+    raise FileNotFoundError('Unable to locate a ChromiumOS checkout')
+
+
+def locate_zephyr_base(checkout, version):
+    """Locate the path to the Zephyr RTOS in a ChromiumOS checkout.
+
+    Args:
+        checkout: The path to the ChromiumOS checkout.
+        version: The requested zephyr version, as a tuple of integers.
+
+    Returns:
+        The path to the Zephyr source.
+    """
+    return (checkout / 'src' / 'third_party' / 'zephyr' / 'main' /
+            'v{}.{}'.format(*version[:2]))
+
+
+def read_kconfig_file(path):
+    """Parse a Kconfig file.
+
+    Args:
+        path: The path to open.
+
+    Returns:
+        A dictionary of kconfig items to their values.
+    """
+    result = {}
+    with open(path) as f:
+        for line in f:
+            line, _, _ = line.partition('#')
+            line = line.strip()
+            if line:
+                name, _, value = line.partition('=')
+                result[name.strip()] = value.strip()
+    return result
+
+
+def write_kconfig_file(path, config, only_if_changed=True):
+    """Write out a dictionary to Kconfig format.
+
+    Args:
+        path: The path to write to.
+        config: The dictionary to write.
+        only_if_changed: Set to True if the file should not be written
+            unless it has changed.
+    """
+    if only_if_changed:
+        if path.exists() and read_kconfig_file(path) == config:
+            return
+    with open(path, "w") as f:
+        for name, value in config.items():
+            f.write('{}={}\n'.format(name, value))
+
+
+def parse_zephyr_version(version_string):
+    """Parse a human-readable version string (e.g., "v2.4") as a tuple.
+
+    Args:
+        version_string: The human-readable version string.
+
+    Returns:
+        A 2-tuple or 3-tuple of integers representing the version.
+    """
+    match = re.fullmatch(r'v?(\d+)[._](\d+)(?:[._](\d+))?', version_string)
+    if not match:
+        raise ValueError(
+            "{} does not look like a Zephyr version.".format(version_string))
+    return tuple(int(x) for x in match.groups() if x is not None)
+
+
+def repr_command(argv):
+    """Represent an argument array as a string.
+
+    Args:
+        argv: The arguments of the command.
+
+    Returns:
+        A string which could be pasted into a shell for execution.
+    """
+    return ' '.join(shlex.quote(str(arg)) for arg in argv)
+
+
+def update_symlink(target_path, link_path):
+    """Create a symlink if it does not exist, or links to a different path.
+
+    Args:
+        target_path: A Path-like object of the desired symlink path.
+        link_path: A Path-like object of the symlink.
+    """
+    target = target_path.resolve()
+    if (not link_path.is_symlink()
+            or pathlib.Path(os.readlink(link_path)).resolve() != target):
+            if link_path.exists():
+                link_path.unlink()
+            link_path.symlink_to(target)
+
+
+def log_multi_line(logger, level, message):
+    """Log a potentially multi-line message to the logger.
+
+    Args:
+        logger: The Logger object to log to.
+        level: The logging level to use when logging.
+        message: The (potentially) multi-line message to log.
+    """
+    for line in message.splitlines():
+        if line:
+            logger.log(level, line)