Refactor command-line parsing. (Steve Leblanc)

1 files changed, 388 insertions, 0 deletions

diff --git a/src/engine/SCons/Optik/option.py b/src/engine/SCons/Optik/option.py
new file mode 100644
index 0000000..2e1ec33
--- /dev/null
+++ b/src/engine/SCons/Optik/option.py
@@ -0,0 +1,388 @@
+"""optik.option
+
+Defines the Option class and some standard value-checking functions.
+"""
+
+__revision__ = "__FILE__ __REVISION__ __DATE__ __DEVELOPER__"
+
+# Original Optik revision this is based on:
+__Optik_revision__ = "option.py,v 1.19.2.1 2002/07/23 01:51:14 gward Exp" 
+
+# Copyright (c) 2001 Gregory P. Ward.  All rights reserved.
+# See the README.txt distributed with Optik for licensing terms.
+
+# created 2001/10/17, GPW (from optik.py)
+
+import sys
+import string
+from types import TupleType, ListType, DictType
+from SCons.Optik.errors import OptionError, OptionValueError
+
+_builtin_cvt = { "int" : (int, "integer"),
+                 "long" : (long, "long integer"),
+                 "float" : (float, "floating-point"),
+                 "complex" : (complex, "complex") }
+
+def check_builtin (option, opt, value):
+    (cvt, what) = _builtin_cvt[option.type]
+    try:
+        return cvt(value)
+    except ValueError:
+        raise OptionValueError(
+            #"%s: invalid %s argument %s" % (opt, what, repr(value)))
+            "option %s: invalid %s value: %s" % (opt, what, repr(value)))
+
+def check_choice(option, opt, value):
+    if value in option.choices:
+        return value
+    else:
+        choices = string.join(map(repr, option.choices),", ")
+        raise OptionValueError(
+            "option %s: invalid choice: %s (choose from %s)"
+            % (opt, repr(value), choices))
+
+# Not supplying a default is different from a default of None,
+# so we need an explicit "not supplied" value.
+NO_DEFAULT = "NO"+"DEFAULT"
+
+
+class Option:
+    """
+    Instance attributes:
+      _short_opts : [string]
+      _long_opts : [string]
+
+      action : string
+      type : string
+      dest : string
+      default : any
+      nargs : int
+      const : any
+      choices : [string]
+      callback : function
+      callback_args : (any*)
+      callback_kwargs : { string : any }
+      help : string
+      metavar : string
+    """
+
+    # The list of instance attributes that may be set through
+    # keyword args to the constructor.
+    ATTRS = ['action',
+             'type',
+             'dest',
+             'default',
+             'nargs',
+             'const',
+             'choices',
+             'callback',
+             'callback_args',
+             'callback_kwargs',
+             'help',
+             'metavar']
+
+    # The set of actions allowed by option parsers.  Explicitly listed
+    # here so the constructor can validate its arguments.
+    ACTIONS = ("store",
+               "store_const",
+               "store_true",
+               "store_false",
+               "append",
+               "count",
+               "callback",
+               "help",
+               "version")
+
+    # The set of actions that involve storing a value somewhere;
+    # also listed just for constructor argument validation.  (If
+    # the action is one of these, there must be a destination.)
+    STORE_ACTIONS = ("store",
+                     "store_const",
+                     "store_true",
+                     "store_false",
+                     "append",
+                     "count")
+
+    # The set of actions for which it makes sense to supply a value
+    # type, ie. where we expect an argument to this option.
+    TYPED_ACTIONS = ("store",
+                     "append",
+                     "callback")
+
+    # The set of known types for option parsers.  Again, listed here for
+    # constructor argument validation.
+    TYPES = ("string", "int", "long", "float", "complex", "choice")
+
+    # Dictionary of argument checking functions, which convert and
+    # validate option arguments according to the option type.
+    # 
+    # Signature of checking functions is:
+    #   check(option : Option, opt : string, value : string) -> any
+    # where
+    #   option is the Option instance calling the checker
+    #   opt is the actual option seen on the command-line
+    #     (eg. "-a", "--file")
+    #   value is the option argument seen on the command-line
+    #
+    # The return value should be in the appropriate Python type
+    # for option.type -- eg. an integer if option.type == "int".
+    # 
+    # If no checker is defined for a type, arguments will be
+    # unchecked and remain strings.
+    TYPE_CHECKER = { "int"    : check_builtin,
+                     "long"   : check_builtin,
+                     "float"  : check_builtin,
+                     "complex"  : check_builtin,
+                     "choice" : check_choice,
+                   }
+
+
+    # CHECK_METHODS is a list of unbound method objects; they are called
+    # by the constructor, in order, after all attributes are
+    # initialized.  The list is created and filled in later, after all
+    # the methods are actually defined.  (I just put it here because I
+    # like to define and document all class attributes in the same
+    # place.)  Subclasses that add another _check_*() method should
+    # define their own CHECK_METHODS list that adds their check method
+    # to those from this class.
+    CHECK_METHODS = None
+                    
+
+    # -- Constructor/initialization methods ----------------------------
+
+    def __init__ (self, *opts, **attrs):
+        # Set _short_opts, _long_opts attrs from 'opts' tuple
+        opts = self._check_opt_strings(opts)
+        self._set_opt_strings(opts)
+
+        # Set all other attrs (action, type, etc.) from 'attrs' dict
+        self._set_attrs(attrs)
+
+        # Check all the attributes we just set.  There are lots of
+        # complicated interdependencies, but luckily they can be farmed
+        # out to the _check_*() methods listed in CHECK_METHODS -- which
+        # could be handy for subclasses!  The one thing these all share
+        # is that they raise OptionError if they discover a problem.
+        for checker in self.CHECK_METHODS:
+            checker(self)
+
+    def _check_opt_strings (self, opts):
+        # Filter out None because early versions of Optik had exactly
+        # one short option and one long option, either of which
+        # could be None.
+        opts = filter(None, opts)
+        if not opts:
+            raise OptionError("at least one option string must be supplied",
+                              self)
+        return opts
+
+    def _set_opt_strings (self, opts):
+        self._short_opts = []
+        self._long_opts = []
+        for opt in opts:
+            if len(opt) < 2:
+                raise OptionError(
+                    "invalid option string %s: "
+                    "must be at least two characters long" % (`opt`,), self)
+            elif len(opt) == 2:
+                if not (opt[0] == "-" and opt[1] != "-"):
+                    raise OptionError(
+                        "invalid short option string %s: "
+                        "must be of the form -x, (x any non-dash char)" % (`opt`,),
+                        self)
+                self._short_opts.append(opt)
+            else:
+                if not (opt[0:2] == "--" and opt[2] != "-"):
+                    raise OptionError(
+                        "invalid long option string %s: "
+                        "must start with --, followed by non-dash" % (`opt`,),
+                        self)
+                self._long_opts.append(opt)
+
+    def _set_attrs (self, attrs):
+        for attr in self.ATTRS:
+            if attrs.has_key(attr):
+                setattr(self, attr, attrs[attr])
+                del attrs[attr]
+            else:
+                if attr == 'default':
+                    setattr(self, attr, NO_DEFAULT)
+                else:
+                    setattr(self, attr, None)
+        if attrs:
+            raise OptionError(
+                "invalid keyword arguments: %s" % string.join(attrs.keys(),", "),
+                self)
+
+
+    # -- Constructor validation methods --------------------------------
+
+    def _check_action (self):
+        if self.action is None:
+            self.action = "store"
+        elif self.action not in self.ACTIONS:
+            raise OptionError("invalid action: %s" % (`self.action`,), self)
+
+    def _check_type (self):
+        if self.type is None:
+            # XXX should factor out another class attr here: list of
+            # actions that *require* a type
+            if self.action in ("store", "append"):
+                if self.choices is not None:
+                    # The "choices" attribute implies "choice" type.
+                    self.type = "choice"
+                else:
+                    # No type given?  "string" is the most sensible default.
+                    self.type = "string"
+        else:
+            if self.type not in self.TYPES:
+                raise OptionError("invalid option type: %s" % (`self.type`,), self)
+            if self.action not in self.TYPED_ACTIONS:
+                raise OptionError(
+                    "must not supply a type for action %s" % (`self.action`,), self)
+
+    def _check_choice(self):
+        if self.type == "choice":
+            if self.choices is None:
+                raise OptionError(
+                    "must supply a list of choices for type 'choice'", self)
+            elif type(self.choices) not in (TupleType, ListType):
+                raise OptionError(
+                    "choices must be a list of strings ('%s' supplied)"
+                    % string.split(str(type(self.choices)),"'")[1], self)
+        elif self.choices is not None:
+            raise OptionError(
+                "must not supply choices for type %s" % (repr(self.type),), self)
+
+    def _check_dest (self):
+        if self.action in self.STORE_ACTIONS and self.dest is None:
+            # No destination given, and we need one for this action.
+            # Glean a destination from the first long option string,
+            # or from the first short option string if no long options.
+            if self._long_opts:
+                # eg. "--foo-bar" -> "foo_bar"
+                self.dest = string.replace(self._long_opts[0][2:],'-', '_')
+            else:
+                self.dest = self._short_opts[0][1]
+
+    def _check_const (self):
+        if self.action != "store_const" and self.const is not None:
+            raise OptionError(
+                "'const' must not be supplied for action %s" % (repr(self.action),),
+                self)
+        
+    def _check_nargs (self):
+        if self.action in self.TYPED_ACTIONS:
+            if self.nargs is None:
+                self.nargs = 1
+        elif self.nargs is not None:
+            raise OptionError(
+                "'nargs' must not be supplied for action %s" % (repr(self.action),),
+                self)
+
+    def _check_callback (self):
+        if self.action == "callback":
+            if not callable(self.callback):
+                raise OptionError(
+                    "callback not callable: %s" % (repr(self.callback),), self)
+            if (self.callback_args is not None and
+                type(self.callback_args) is not TupleType):
+                raise OptionError(
+                    "callback_args, if supplied, must be a tuple: not %s"
+                    % (repr(self.callback_args),), self)
+            if (self.callback_kwargs is not None and
+                type(self.callback_kwargs) is not DictType):
+                raise OptionError(
+                    "callback_kwargs, if supplied, must be a dict: not %s"
+                    % (repr(self.callback_kwargs),), self)
+        else:
+            if self.callback is not None:
+                raise OptionError(
+                    "callback supplied (%s) for non-callback option"
+                    % (repr(self.callback),), self)
+            if self.callback_args is not None:
+                raise OptionError(
+                    "callback_args supplied for non-callback option", self)
+            if self.callback_kwargs is not None:
+                raise OptionError(
+                    "callback_kwargs supplied for non-callback option", self)
+
+
+    CHECK_METHODS = [_check_action,
+                     _check_type,
+                     _check_choice,
+                     _check_dest,
+                     _check_const,
+                     _check_nargs,
+                     _check_callback]
+        
+
+    # -- Miscellaneous methods -----------------------------------------
+
+    def __str__ (self):
+        if self._short_opts or self._long_opts:
+            return string.join(self._short_opts + self._long_opts,"/")
+        else:
+            raise RuntimeError, "short_opts and long_opts both empty!"
+
+    def takes_value (self):
+        return self.type is not None
+
+
+    # -- Processing methods --------------------------------------------
+
+    def check_value (self, opt, value):
+        checker = self.TYPE_CHECKER.get(self.type)
+        if checker is None:
+            return value
+        else:
+            return checker(self, opt, value)
+
+    def process (self, opt, value, values, parser):
+
+        # First, convert the value(s) to the right type.  Howl if any
+        # value(s) are bogus.
+        if value is not None:
+            if self.nargs == 1:
+                value = self.check_value(opt, value)
+            else:
+		def cv(v,check=self.check_value,o=opt):
+		    return check(o,v)
+
+                value = tuple(map(cv,value))
+
+        # And then take whatever action is expected of us.
+        # This is a separate method to make life easier for
+        # subclasses to add new actions.
+        return self.take_action(
+            self.action, self.dest, opt, value, values, parser)
+
+    def take_action (self, action, dest, opt, value, values, parser):
+        if action == "store":
+            setattr(values, dest, value)
+        elif action == "store_const":
+            setattr(values, dest, self.const)
+        elif action == "store_true":
+            setattr(values, dest, 1)
+        elif action == "store_false":
+            setattr(values, dest, 0)
+        elif action == "append":
+            values.ensure_value(dest, []).append(value)
+        elif action == "count":
+            setattr(values, dest, values.ensure_value(dest, 0) + 1)
+        elif action == "callback":
+            args = self.callback_args or ()
+            kwargs = self.callback_kwargs or {}
+            apply( self.callback, (self, opt, value, parser,)+ args, kwargs)
+        elif action == "help":
+            parser.print_help()
+            sys.exit(0)
+        elif action == "version":
+            parser.print_version()
+            sys.exit(0)
+        else:
+            raise RuntimeError, "unknown action %s" % (repr(self.action),)
+
+        return 1
+
+# class Option