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>

3 files changed, 204 insertions, 169 deletions

diff --git a/tools/dtoc/dtb_platdata.py b/tools/dtoc/dtb_platdata.py
index f1c09d629ff..ad642f30625 100644
--- a/tools/dtoc/dtb_platdata.py
+++ b/tools/dtoc/dtb_platdata.py
@@ -22,6 +22,8 @@ import sys
 
 from dtoc import fdt
 from dtoc import fdt_util
+from dtoc import src_scan
+from dtoc.src_scan import conv_name_to_c
 
 # When we see these properties we ignore them - i.e. do not create a structure
 # member
@@ -76,39 +78,6 @@ PhandleInfo = collections.namedtuple('PhandleInfo', ['max_args', 'args'])
 PhandleLink = collections.namedtuple('PhandleLink', ['var_node', 'dev_name'])
 
 
-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
-
-
-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 tab_to(num_tabs, line):
     """Append tabs to a line of text to reach a tab stop.
 
@@ -154,19 +123,6 @@ def get_value(ftype, value):
         val = '%#x' % value
     return val
 
-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 DtbPlatdata():
     """Provide a means to convert device tree binary data to platform data
@@ -176,22 +132,15 @@ class DtbPlatdata():
     code is not affordable.
 
     Properties:
+        _scan: Scan object, for scanning and reporting on useful information
+            from the U-Boot source code
         _fdt: Fdt object, referencing the device tree
         _dtb_fname: Filename of the input device tree binary file
         _valid_nodes: A list of Node object with compatible strings. The list
             is ordered by conv_name_to_c(node.name)
         _include_disabled: true to include nodes marked status = "disabled"
         _outfile: The current output file (sys.stdout or a real file)
-        _warning_disabled: true to disable warnings about driver names not found
         _lines: Stashed list of output lines for outputting in the future
-        _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 of additional drivers to use during scanning
         _dirname: Directory to hold output files, or None for none (all files
             go to stdout)
         _struct_data (dict): OrderedDict of dtplat structures to output
@@ -201,58 +150,18 @@ class DtbPlatdata():
                         value: Prop object with field information
         _basedir (str): Base directory of source tree
     """
-    def __init__(self, dtb_fname, include_disabled, warning_disabled,
-                 drivers_additional=None):
+    def __init__(self, scan, dtb_fname, include_disabled):
+        self._scan = scan
         self._fdt = None
         self._dtb_fname = dtb_fname
         self._valid_nodes = None
         self._include_disabled = include_disabled
         self._outfile = None
-        self._warning_disabled = warning_disabled
         self._lines = []
-        self._drivers = {}
-        self._driver_aliases = {}
-        self._drivers_additional = drivers_additional or []
         self._dirnames = [None] * len(Ftype)
         self._struct_data = collections.OrderedDict()
         self._basedir = None
 
-    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 setup_output_dirs(self, output_dirs):
         """Set up the output directories
 
@@ -407,65 +316,6 @@ class DtbPlatdata():
             return PhandleInfo(max_args, args)
         return None
 
-    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, basedir=None):
-        """Scan the driver folders to build a list of driver names and aliases
-
-        This procedure will populate self._drivers and self._driver_aliases
-
-        """
-        if not basedir:
-            basedir = sys.argv[0].replace('tools/dtoc/dtoc', '')
-            if basedir == '':
-                basedir = './'
-        self._basedir = basedir
-        for (dirpath, _, filenames) in os.walk(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(basedir + '/' + fname)
-
     def scan_dtb(self):
         """Scan the device tree to obtain a tree of nodes and properties
 
@@ -584,7 +434,7 @@ class DtbPlatdata():
         """
         structs = self._struct_data
         for node in self._valid_nodes:
-            node_name, _ = self.get_normalized_compat_name(node)
+            node_name, _ = self._scan.get_normalized_compat_name(node)
             fields = {}
 
             # Get a list of all the valid properties in this node.
@@ -607,7 +457,7 @@ class DtbPlatdata():
                 structs[node_name] = fields
 
         for node in self._valid_nodes:
-            node_name, _ = self.get_normalized_compat_name(node)
+            node_name, _ = self._scan.get_normalized_compat_name(node)
             struct = structs[node_name]
             for name, prop in node.props.items():
                 if name not in PROP_IGNORE_LIST and name[0] != '#':
@@ -772,7 +622,7 @@ class DtbPlatdata():
         Args:
             node (fdt.Node): node to output
         """
-        struct_name, _ = self.get_normalized_compat_name(node)
+        struct_name, _ = self._scan.get_normalized_compat_name(node)
         var_name = conv_name_to_c(node.name)
         self.buf('/* Node %s index %d */\n' % (node.path, node.idx))
 
@@ -845,9 +695,9 @@ def run_steps(args, dtb_file, include_disabled, output, output_dirs,
     if output and output_dirs and any(output_dirs):
         raise ValueError('Must specify either output or output_dirs, not both')
 
-    plat = DtbPlatdata(dtb_file, include_disabled, warning_disabled,
-                       drivers_additional)
-    plat.scan_drivers(basedir)
+    scan = src_scan.Scanner(basedir, drivers_additional, warning_disabled)
+    plat = DtbPlatdata(scan, dtb_file, include_disabled)
+    scan.scan_drivers()
     plat.scan_dtb()
     plat.scan_tree()
     plat.scan_reg_sizes()
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)
diff --git a/tools/dtoc/test_dtoc.py b/tools/dtoc/test_dtoc.py
index bcbf58c45bc..8e8dd847c10 100755
--- a/tools/dtoc/test_dtoc.py
+++ b/tools/dtoc/test_dtoc.py
@@ -18,13 +18,14 @@ import tempfile
 import unittest
 from unittest import mock
 
-from dtb_platdata import conv_name_to_c
-from dtb_platdata import get_compat_name
 from dtb_platdata import get_value
 from dtb_platdata import tab_to
 from dtoc import dtb_platdata
 from dtoc import fdt
 from dtoc import fdt_util
+from dtoc import src_scan
+from dtoc.src_scan import conv_name_to_c
+from dtoc.src_scan import get_compat_name
 from patman import test_util
 from patman import tools
 
@@ -933,9 +934,9 @@ U_BOOT_DRVINFO(spl_test2) = {
 
     def test_driver(self):
         """Test the Driver class"""
-        drv1 = dtb_platdata.Driver('fred')
-        drv2 = dtb_platdata.Driver('mary')
-        drv3 = dtb_platdata.Driver('fred')
+        drv1 = src_scan.Driver('fred')
+        drv2 = src_scan.Driver('mary')
+        drv3 = src_scan.Driver('fred')
         self.assertEqual("Driver(name='fred')", str(drv1))
         self.assertEqual(drv1, drv3)
         self.assertNotEqual(drv1, drv2)
@@ -989,8 +990,7 @@ U_BOOT_DRVINFO(spl_test2) = {
 
             # Mock out scan_driver and check that it is called with the
             # expected files
-            with mock.patch.object(dtb_platdata.DtbPlatdata, "scan_driver") \
-                    as mocked:
+            with mock.patch.object(src_scan.Scanner, "scan_driver")  as mocked:
                 dtb_platdata.run_steps(['all'], dtb_file, False, None, [outdir],
                                        True, basedir=indir)
             self.assertEqual(2, len(mocked.mock_calls))