Very basic option parser skeleton.

1 files changed, 115 insertions, 0 deletions

diff --git a/optinterpreter.py b/optinterpreter.py
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+# Copyright 2013 Jussi Pakkanen
+
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+
+#     http://www.apache.org/licenses/LICENSE-2.0
+
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import mparser
+import coredata
+import nodes
+import os
+
+class OptionException(coredata.MesonException):
+    pass
+
+class UserOption:
+    def __init__(self, kwargs):
+        super().__init__()
+
+class UserStringOption(UserOption):
+    def __init__(self, kwargs):
+        super().__init__(kwargs)
+        self.value = kwargs.get('value', '')
+        if not isinstance(self.value, str):
+            raise OptionException('Value of string option is not a string')
+
+option_types = {'string' : UserStringOption,
+                }
+
+class OptionInterpreter:
+    def __init__(self):
+        self.options = {}
+    
+    def process(self, option_file):
+        try:
+            ast = mparser.build_ast(open(option_file, 'r').read())
+        except coredata.MesonException as me:
+            me.file = option_file
+            raise me
+        if not isinstance(ast, nodes.CodeBlock):
+            e = OptionException('Option file is malformed.')
+            e.lineno = ast.lineno()
+            raise e
+        statements = ast.get_statements()
+        i = 0
+        while i < len(statements):
+            cur = statements[i]
+            try:
+                self.evaluate_statement(cur)
+            except Exception as e:
+                e.lineno = cur.lineno()
+                e.file = os.path.join('options.txt')
+                raise e
+            i += 1 # In THE FUTURE jump over blocks and stuff.
+        print(self.options)
+
+    def reduce_single(self, arg):
+        if isinstance(arg, nodes.AtomExpression) or isinstance(arg, nodes.AtomStatement):
+            return self.get_variable(arg.value)
+        elif isinstance(arg, str):
+            return arg
+        elif isinstance(arg, nodes.StringExpression) or isinstance(arg, nodes.StringStatement):
+            return arg.get_value()
+        elif isinstance(arg, nodes.BoolStatement) or isinstance(arg, nodes.BoolExpression):
+            return arg.get_value()
+        elif isinstance(arg, nodes.ArrayStatement):
+            return [self.reduce_single(curarg) for curarg in arg.args.arguments]
+        elif isinstance(arg, nodes.IntStatement):
+            return arg.get_value()
+        else:
+            raise OptionException('Arguments may only be string, int, bool, or array of those.')
+
+    def reduce_arguments(self, args):
+        assert(isinstance(args, nodes.Arguments))
+        if args.incorrect_order():
+            raise OptionException('All keyword arguments must be after positional arguments.')
+        reduced_pos = [self.reduce_single(arg) for arg in args.arguments]
+        reduced_kw = {}
+        for key in args.kwargs.keys():
+            if not isinstance(key, str):
+                raise OptionException('Keyword argument name is not a string.')
+            a = args.kwargs[key]
+            reduced_kw[key] = self.reduce_single(a)
+        return (reduced_pos, reduced_kw)
+
+    def evaluate_statement(self, node):
+        if not isinstance(node, nodes.FunctionCall):
+            raise OptionException('Option file may only contain option definitions')
+        func_name = node.get_function_name()
+        if func_name != 'option':
+            raise OptionException('Only calls to option() are allowed in option files.')
+        (posargs, kwargs) = self.reduce_arguments(node.arguments)
+        if 'type' not in kwargs:
+            raise OptionException('Option call missing mandatory "type" keyword argument')
+        opt_type = kwargs['type']
+        if not opt_type in option_types:
+            raise OptionException('Unknown type %s.' % opt_type)
+        if len(posargs) != 1:
+            raise OptionException('Option all must have one (and only one) positional argument')
+        opt_name = posargs[0]
+        if not isinstance(opt_name, str):
+            raise OptionException('Positional argument must be a string.')
+        self.options[opt_name] = option_types[opt_type](kwargs)
+
+if __name__ == '__main__':
+    import sys
+    oi = OptionInterpreter()
+    oi.process(sys.argv[1])