patman: Add the concept of multiple projects

There are cases that we want to support different settings (or maybe
even different aliases) for different projects.  Add support for this
by:
* Adding detection for two big projects: U-Boot and Linux.
* Adding default settings for Linux (U-Boot is already good with the
  standard patman defaults).
* Extend the new "settings" feature in .patman to specify per-project
  settings.

Signed-off-by: Doug Anderson <dianders@chromium.org>
Acked-by: Simon Glass <sjg@chromium.org>

tools/patman/settings.py

@@ -26,6 +26,140 @@ import re
 import command
 import gitutil
 
+"""Default settings per-project.
+
+These are used by _ProjectConfigParser.  Settings names should match
+the "dest" of the option parser from patman.py.
+"""
+_default_settings = {
+    "u-boot": {},
+    "linux": {
+        "process_tags": "False",
+    }
+}
+
+class _ProjectConfigParser(ConfigParser.SafeConfigParser):
+    """ConfigParser that handles projects.
+
+    There are two main goals of this class:
+    - Load project-specific default settings.
+    - Merge general default settings/aliases with project-specific ones.
+
+    # Sample config used for tests below...
+    >>> import StringIO
+    >>> sample_config = '''
+    ... [alias]
+    ... me: Peter P. <likesspiders@example.com>
+    ... enemies: Evil <evil@example.com>
+    ...
+    ... [sm_alias]
+    ... enemies: Green G. <ugly@example.com>
+    ...
+    ... [sm2_alias]
+    ... enemies: Doc O. <pus@example.com>
+    ...
+    ... [settings]
+    ... am_hero: True
+    ... '''
+
+    # Check to make sure that bogus project gets general alias.
+    >>> config = _ProjectConfigParser("zzz")
+    >>> config.readfp(StringIO.StringIO(sample_config))
+    >>> config.get("alias", "enemies")
+    'Evil <evil@example.com>'
+
+    # Check to make sure that alias gets overridden by project.
+    >>> config = _ProjectConfigParser("sm")
+    >>> config.readfp(StringIO.StringIO(sample_config))
+    >>> config.get("alias", "enemies")
+    'Green G. <ugly@example.com>'
+
+    # Check to make sure that settings get merged with project.
+    >>> config = _ProjectConfigParser("linux")
+    >>> config.readfp(StringIO.StringIO(sample_config))
+    >>> sorted(config.items("settings"))
+    [('am_hero', 'True'), ('process_tags', 'False')]
+
+    # Check to make sure that settings works with unknown project.
+    >>> config = _ProjectConfigParser("unknown")
+    >>> config.readfp(StringIO.StringIO(sample_config))
+    >>> sorted(config.items("settings"))
+    [('am_hero', 'True')]
+    """
+    def __init__(self, project_name):
+        """Construct _ProjectConfigParser.
+
+        In addition to standard SafeConfigParser initialization, this also loads
+        project defaults.
+
+        Args:
+            project_name: The name of the project.
+        """
+        self._project_name = project_name
+        ConfigParser.SafeConfigParser.__init__(self)
+
+        # Update the project settings in the config based on
+        # the _default_settings global.
+        project_settings = "%s_settings" % project_name
+        if not self.has_section(project_settings):
+            self.add_section(project_settings)
+        project_defaults = _default_settings.get(project_name, {})
+        for setting_name, setting_value in project_defaults.iteritems():
+            self.set(project_settings, setting_name, setting_value)
+
+    def get(self, section, option, *args, **kwargs):
+        """Extend SafeConfigParser to try project_section before section.
+
+        Args:
+            See SafeConfigParser.
+        Returns:
+            See SafeConfigParser.
+        """
+        try:
+            return ConfigParser.SafeConfigParser.get(
+                self, "%s_%s" % (self._project_name, section), option,
+                *args, **kwargs
+            )
+        except (ConfigParser.NoSectionError, ConfigParser.NoOptionError):
+            return ConfigParser.SafeConfigParser.get(
+                self, section, option, *args, **kwargs
+            )
+
+    def items(self, section, *args, **kwargs):
+        """Extend SafeConfigParser to add project_section to section.
+
+        Args:
+            See SafeConfigParser.
+        Returns:
+            See SafeConfigParser.
+        """
+        project_items = []
+        has_project_section = False
+        top_items = []
+
+        # Get items from the project section
+        try:
+            project_items = ConfigParser.SafeConfigParser.items(
+                self, "%s_%s" % (self._project_name, section), *args, **kwargs
+            )
+            has_project_section = True
+        except ConfigParser.NoSectionError:
+            pass
+
+        # Get top-level items
+        try:
+            top_items = ConfigParser.SafeConfigParser.items(
+                self, section, *args, **kwargs
+            )
+        except ConfigParser.NoSectionError:
+            # If neither section exists raise the error on...
+            if not has_project_section:
+                raise
+
+        item_dict = dict(top_items)
+        item_dict.update(project_items)
+        return item_dict.items()
+
 def ReadGitAliases(fname):
     """Read a git alias file. This is in the form used by git:
 
@@ -102,7 +236,7 @@ def _UpdateDefaults(parser, config):
     Args:
         parser: An instance of an OptionParser whose defaults will be
             updated.
-        config: An instance of SafeConfigParser that we will query
+        config: An instance of _ProjectConfigParser that we will query
             for settings.
     """
     defaults = parser.get_default_values()
@@ -117,14 +251,16 @@ def _UpdateDefaults(parser, config):
         else:
             print "WARNING: Unknown setting %s" % name
 
-def Setup(parser, config_fname=''):
+def Setup(parser, project_name, config_fname=''):
     """Set up the settings module by reading config files.
 
     Args:
         parser:         The parser to update
+        project_name:   Name of project that we're working on; we'll look
+            for sections named "project_section" as well.
         config_fname:   Config filename to read ('' for default)
     """
-    config = ConfigParser.SafeConfigParser()
+    config = _ProjectConfigParser(project_name)
     if config_fname == '':
         config_fname = '%s/.patman' % os.getenv('HOME')
 
@@ -141,3 +277,8 @@ def Setup(parser, config_fname=''):
 
 # These are the aliases we understand, indexed by alias. Each member is a list.
 alias = {}
+
+if __name__ == "__main__":
+    import doctest
+
+    doctest.testmod()