dtoc: Split source-code scanning to a separate file

Before expanding the scanning features any more, move this into a separate
file. This will make it easier to maintain in the future. In particular,
it reduces the size of dtb_platdata.py and allows us to add tests
specifically for scanning, without going through that file.

The pieces moved are the Driver class, the scanning code and the various
naming functions, since they mostly depend on the scanning results.

So far there is are no separate tests for src_scan. These will be added
as new functionality appears.

This introduces no functional change.

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

1 files changed, 185 insertions, 0 deletions

diff --git a/tools/dtoc/src_scan.py b/tools/dtoc/src_scan.py
new file mode 100644
index 00000000000..185a6d9284d
--- /dev/null
+++ b/tools/dtoc/src_scan.py
@@ -0,0 +1,185 @@
+#!/usr/bin/python
+# SPDX-License-Identifier: GPL-2.0+
+#
+# Copyright (C) 2017 Google, Inc
+# Written by Simon Glass <sjg@chromium.org>
+#
+
+"""Scanning of U-Boot source for drivers and structs
+
+This scans the source tree to find out things about all instances of
+U_BOOT_DRIVER(), UCLASS_DRIVER and all struct declarations in header files.
+
+See doc/driver-model/of-plat.rst for more informaiton
+"""
+
+import os
+import re
+import sys
+
+
+def conv_name_to_c(name):
+    """Convert a device-tree name to a C identifier
+
+    This uses multiple replace() calls instead of re.sub() since it is faster
+    (400ms for 1m calls versus 1000ms for the 're' version).
+
+    Args:
+        name (str): Name to convert
+    Return:
+        str: String containing the C version of this name
+    """
+    new = name.replace('@', '_at_')
+    new = new.replace('-', '_')
+    new = new.replace(',', '_')
+    new = new.replace('.', '_')
+    return new
+
+def get_compat_name(node):
+    """Get the node's list of compatible string as a C identifiers
+
+    Args:
+        node (fdt.Node): Node object to check
+    Return:
+        list of str: List of C identifiers for all the compatible strings
+    """
+    compat = node.props['compatible'].value
+    if not isinstance(compat, list):
+        compat = [compat]
+    return [conv_name_to_c(c) for c in compat]
+
+
+class Driver:
+    """Information about a driver in U-Boot
+
+    Attributes:
+        name: Name of driver. For U_BOOT_DRIVER(x) this is 'x'
+    """
+    def __init__(self, name):
+        self.name = name
+
+    def __eq__(self, other):
+        return self.name == other.name
+
+    def __repr__(self):
+        return "Driver(name='%s')" % self.name
+
+
+class Scanner:
+    """Scanning of the U-Boot source tree
+
+    Properties:
+        _basedir (str): Base directory of U-Boot source code. Defaults to the
+            grandparent of this file's directory
+        _drivers: Dict of valid driver names found in drivers/
+            key: Driver name
+            value: Driver for that driver
+        _driver_aliases: Dict that holds aliases for driver names
+            key: Driver alias declared with
+                DM_DRIVER_ALIAS(driver_alias, driver_name)
+            value: Driver name declared with U_BOOT_DRIVER(driver_name)
+        _drivers_additional (list or str): List of additional drivers to use
+            during scanning
+        _warning_disabled: true to disable warnings about driver names not found
+    """
+    def __init__(self, basedir, drivers_additional, warning_disabled):
+        """Set up a new Scanner
+        """
+        if not basedir:
+            basedir = sys.argv[0].replace('tools/dtoc/dtoc', '')
+            if basedir == '':
+                basedir = './'
+        self._basedir = basedir
+        self._drivers = {}
+        self._driver_aliases = {}
+        self._drivers_additional = drivers_additional or []
+        self._warning_disabled = warning_disabled
+
+    def get_normalized_compat_name(self, node):
+        """Get a node's normalized compat name
+
+        Returns a valid driver name by retrieving node's list of compatible
+        string as a C identifier and performing a check against _drivers
+        and a lookup in driver_aliases printing a warning in case of failure.
+
+        Args:
+            node (Node): Node object to check
+        Return:
+            Tuple:
+                Driver name associated with the first compatible string
+                List of C identifiers for all the other compatible strings
+                    (possibly empty)
+                In case of no match found, the return will be the same as
+                get_compat_name()
+        """
+        compat_list_c = get_compat_name(node)
+
+        for compat_c in compat_list_c:
+            if not compat_c in self._drivers.keys():
+                compat_c = self._driver_aliases.get(compat_c)
+                if not compat_c:
+                    continue
+
+            aliases_c = compat_list_c
+            if compat_c in aliases_c:
+                aliases_c.remove(compat_c)
+            return compat_c, aliases_c
+
+        if not self._warning_disabled:
+            print('WARNING: the driver %s was not found in the driver list'
+                  % (compat_list_c[0]))
+
+        return compat_list_c[0], compat_list_c[1:]
+
+    def scan_driver(self, fname):
+        """Scan a driver file to build a list of driver names and aliases
+
+        This procedure will populate self._drivers and self._driver_aliases
+
+        Args
+            fname: Driver filename to scan
+        """
+        with open(fname, encoding='utf-8') as inf:
+            try:
+                buff = inf.read()
+            except UnicodeDecodeError:
+                # This seems to happen on older Python versions
+                print("Skipping file '%s' due to unicode error" % fname)
+                return
+
+            # The following re will search for driver names declared as
+            # U_BOOT_DRIVER(driver_name)
+            drivers = re.findall(r'U_BOOT_DRIVER\((.*)\)', buff)
+
+            for driver in drivers:
+                self._drivers[driver] = Driver(driver)
+
+            # The following re will search for driver aliases declared as
+            # DM_DRIVER_ALIAS(alias, driver_name)
+            driver_aliases = re.findall(
+                r'DM_DRIVER_ALIAS\(\s*(\w+)\s*,\s*(\w+)\s*\)',
+                buff)
+
+            for alias in driver_aliases: # pragma: no cover
+                if len(alias) != 2:
+                    continue
+                self._driver_aliases[alias[1]] = alias[0]
+
+    def scan_drivers(self):
+        """Scan the driver folders to build a list of driver names and aliases
+
+        This procedure will populate self._drivers and self._driver_aliases
+        """
+        for (dirpath, _, filenames) in os.walk(self._basedir):
+            for fname in filenames:
+                if not fname.endswith('.c'):
+                    continue
+                self.scan_driver(dirpath + '/' + fname)
+
+        for fname in self._drivers_additional:
+            if not isinstance(fname, str) or len(fname) == 0:
+                continue
+            if fname[0] == '/':
+                self.scan_driver(fname)
+            else:
+                self.scan_driver(self._basedir + '/' + fname)