Split generate_global_constructors.py from compute_interfaces_info.py

Source/bindings/scripts/utilities.py

+# Copyright 2014 The Chromium Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+"""Utility functions (file reading, simple IDL parsing by regexes) for IDL build."""
+
+import os
+import cPickle as pickle
+import re
+import string
+
+
+class IdlBadFilenameError(Exception):
+    """Raised if an IDL filename disagrees with the interface name in the file."""
+    pass
+
+
+################################################################################
+# Basic file reading/writing
+################################################################################
+
+def get_file_contents(filename):
+    with open(filename) as f:
+        return ''.join(f.readlines())
+
+
+def write_file(new_lines, destination_filename, only_if_changed):
+    if only_if_changed and os.path.isfile(destination_filename):
+        with open(destination_filename) as destination_file:
+            if destination_file.readlines() == new_lines:
+                return
+    with open(destination_filename, 'w') as destination_file:
+        destination_file.write(''.join(new_lines))
+
+
+def write_pickle_file(pickle_filename, data, only_if_changed):
+    if only_if_changed and os.path.isfile(pickle_filename):
+        with open(pickle_filename) as pickle_file:
+            if pickle.load(pickle_file) == data:
+                return
+    with open(pickle_filename, 'w') as pickle_file:
+        pickle.dump(data, pickle_file)
+
+
+################################################################################
+# IDL parsing
+#
+# We use regular expressions for parsing; this is incorrect (Web IDL is not a
+# regular language), but simple and sufficient in practice.
+# Leading and trailing context (e.g. following '{') used to avoid false matches.
+################################################################################
+
+def get_partial_interface_name_from_idl(file_contents):
+    match = re.search(r'partial\s+interface\s+(\w+)\s*{', file_contents)
+    return match and match.group(1)
+
+
+def get_implemented_interfaces_from_idl(file_contents, interface_name):
+    # Rule is: identifier-A implements identifier-B;
+    # http://www.w3.org/TR/WebIDL/#idl-implements-statements
+    def get_implemented(left_identifier, right_identifier):
+        # identifier-A must be the current interface
+        if left_identifier != interface_name:
+            raise IdlBadFilenameError("Identifier on the left of the 'implements' statement should be %s in %s.idl, but found %s" % (interface_name, interface_name, left_identifier))
+        return right_identifier
+
+    implements_re = (r'^\s*'
+                     r'(\w+)\s+'
+                     r'implements\s+'
+                     r'(\w+)\s*'
+                     r';')
+    implements_matches = re.finditer(implements_re, file_contents, re.MULTILINE)
+    implements_pairs = [(match.group(1), match.group(2))
+                        for match in implements_matches]
+    return [get_implemented(left, right) for left, right in implements_pairs]
+
+
+def is_callback_interface_from_idl(file_contents):
+    match = re.search(r'callback\s+interface\s+\w+\s*{', file_contents)
+    return bool(match)
+
+
+def get_parent_interface(file_contents):
+    match = re.search(r'interface\s+'
+                      r'\w+\s*'
+                      r':\s*(\w+)\s*'
+                      r'{',
+                      file_contents)
+    return match and match.group(1)
+
+
+def get_interface_extended_attributes_from_idl(file_contents):
+    match = re.search(r'\[(.*)\]\s*'
+                      r'((callback|partial)\s+)?'
+                      r'(interface|exception)\s+'
+                      r'\w+\s*'
+                      r'(:\s*\w+\s*)?'
+                      r'{',
+                      file_contents, flags=re.DOTALL)
+    if not match:
+        return {}
+    # Strip comments
+    # re.compile needed b/c Python 2.6 doesn't support flags in re.sub
+    single_line_comment_re = re.compile(r'//.*$', flags=re.MULTILINE)
+    block_comment_re = re.compile(r'/\*.*?\*/', flags=re.MULTILINE | re.DOTALL)
+    extended_attributes_string = re.sub(single_line_comment_re, '', match.group(1))
+    extended_attributes_string = re.sub(block_comment_re, '', extended_attributes_string)
+    extended_attributes = {}
+    # FIXME: this splitting is WRONG: it fails on ExtendedAttributeArgList like
+    # 'NamedConstructor=Foo(a, b)'
+    parts = [extended_attribute.strip()
+             for extended_attribute in extended_attributes_string.split(',')
+             # Discard empty parts, which may exist due to trailing comma
+             if extended_attribute.strip()]
+    for part in parts:
+        name, _, value = map(string.strip, part.partition('='))
+        extended_attributes[name] = value
+    return extended_attributes
+
+
+def get_put_forward_interfaces_from_idl(file_contents):
+    put_forwards_pattern = (r'\[[^\]]*PutForwards=[^\]]*\]\s+'
+                            r'readonly\s+'
+                            r'attribute\s+'
+                            r'(\w+)')
+    return sorted(set(match.group(1)
+                      for match in re.finditer(put_forwards_pattern,
+                                               file_contents,
+                                               flags=re.DOTALL)))