IDL parser rewrite in Python

Source/bindings/scripts/idl_validator.py

Index: Source/bindings/scripts/idl_validator.py
diff --git a/Source/bindings/scripts/idl_validator.py b/Source/bindings/scripts/idl_validator.py
new file mode 100644
index 0000000000000000000000000000000000000000..4e60fb8010b96d512ee628ef98bf5b3ee8eb9978
--- /dev/null
+++ b/Source/bindings/scripts/idl_validator.py
@@ -0,0 +1,110 @@
+# Copyright (C) 2013 Google Inc. All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met:
+#
+#     * Redistributions of source code must retain the above copyright
+# notice, this list of conditions and the following disclaimer.
+#     * Redistributions in binary form must reproduce the above
+# copyright notice, this list of conditions and the following disclaimer
+# in the documentation and/or other materials provided with the
+# distribution.
+#     * Neither the name of Google Inc. nor the names of its
+# contributors may be used to endorse or promote products derived from
+# this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+"""Validate extended attributes."""
+
+
+import re
+
+
+class IDLExtendedAttributeFileFormatError(Exception):
+    pass
+
+
+class IDLInvalidExtendedAttributeError(Exception):
+    pass
+
+
+def validate_extended_attributes(definitions, basename, idl_attributes_filename):
+    extended_attribute_validator = IDLExtendedAttributeValidator(idl_attributes_filename)
+    extended_attribute_validator.validate_extended_attributes(definitions, basename)
+
+
+def read_extended_attributes_file(extended_attributes_filename):
+    valid_extended_attributes = {}
+    with open(extended_attributes_filename) as extended_attributes_file:
+        for line in extended_attributes_file:
+            line = line.strip()
+            if not line or line.startswith('#'):
+                continue
+            name, _, values_string = map(str.strip, line.partition('='))
+            if not name:
+                raise IDLExtendedAttributeFileFormatError('The format of %s is wrong, in line "%s"' % (extended_attributes_filename, line))
+            valid_extended_attributes[name] = set()
+            value_list = values_string.split('|')
+            if not value_list:
+                valid_extended_attributes[name].add(None)
+                continue
+            for value in value_list:
+                value = value.strip()
+                if not value:
+                    value = None
+                valid_extended_attributes[name].add(value)
+    return valid_extended_attributes
+
+
+class IDLExtendedAttributeValidator:
+    def __init__(self, extended_attributes_filename):
+        self.valid_extended_attributes = read_extended_attributes_file(extended_attributes_filename)
+
+    def validate_extended_attributes(self, definitions, idl_filename):
+        # FIXME: this should be done when parsing the file, rather than after.
+        try:
+            for interface in definitions.interfaces.itervalues():
+                self.validate_extended_attributes_node(interface)
+                for attribute in interface.attributes:
+                    self.validate_extended_attributes_node(attribute)
+                for operation in interface.operations:
+                    self.validate_extended_attributes_node(operation)
+                    for argument in operation.arguments:
+                        self.validate_extended_attributes_node(argument)
+        except IDLInvalidExtendedAttributeError, error:
+            raise IDLInvalidExtendedAttributeError("""IDL ATTRIBUTE ERROR in file %s:
+%s
+If you want to add a new IDL extended attribute, please add it to bindings/scripts/IDLAttributes.txt and add an explanation to the Blink IDL document at http://chromium.org/blink/webidl
+""" % (idl_filename, str(error)))
+
+    def validate_extended_attributes_node(self, node):
+        for name, values_string in node.extended_attributes.iteritems():
+            self.validate_name_values_string(name, values_string)
+
+    def validate_name_values_string(self, name, values_string):
+        if name == 'ImplementedBy':  # attribute added when merging interfaces
+            return
+        if name not in self.valid_extended_attributes:
+            raise IDLInvalidExtendedAttributeError('Unknown extended attribute [%s]' % name)
+        valid_values = self.valid_extended_attributes[name]
+        if '*' in valid_values:  # wildcard, any value ok
+            return
+        if values_string is None:
+            value_list = [None]
+        else:
+            value_list = re.split('[|&]', values_string)
+        for value in value_list:
+            if value not in valid_values:
+                raise IDLInvalidExtendedAttributeError('Invalid value "%s" found in extended attribute [%s=%s]' % (value, name, values_string))