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1 #!/usr/bin/env python | |
2 # Copyright (c) 2012 The Chromium Authors. All rights reserved. | |
3 # Use of this source code is governed by a BSD-style license that can be | |
4 # found in the LICENSE file. | |
5 | |
6 '''Class for reading GRD files into memory, without processing them. | |
7 ''' | |
8 | |
9 import os.path | |
10 import types | |
11 import xml.sax | |
12 import xml.sax.handler | |
13 | |
14 from grit import exception | |
15 from grit import util | |
16 from grit.node import base | |
17 from grit.node import mapping | |
18 from grit.node import misc | |
19 | |
20 | |
21 class StopParsingException(Exception): | |
22 '''An exception used to stop parsing.''' | |
23 pass | |
24 | |
25 | |
26 class GrdContentHandler(xml.sax.handler.ContentHandler): | |
27 def __init__(self, stop_after, debug, dir, defines, tags_to_ignore, | |
28 target_platform): | |
29 # Invariant of data: | |
30 # 'root' is the root of the parse tree being created, or None if we haven't | |
31 # parsed out any elements. | |
32 # 'stack' is the a stack of elements that we push new nodes onto and | |
33 # pop from when they finish parsing, or [] if we are not currently parsing. | |
34 # 'stack[-1]' is the top of the stack. | |
35 self.root = None | |
36 self.stack = [] | |
37 self.stop_after = stop_after | |
38 self.debug = debug | |
39 self.dir = dir | |
40 self.defines = defines | |
41 self.tags_to_ignore = tags_to_ignore or set() | |
42 self.ignore_depth = 0 | |
43 self.target_platform = target_platform | |
44 | |
45 def startElement(self, name, attrs): | |
46 if self.ignore_depth or name in self.tags_to_ignore: | |
47 if self.debug and self.ignore_depth == 0: | |
48 print "Ignoring element %s and its children" % name | |
49 self.ignore_depth += 1 | |
50 return | |
51 | |
52 if self.debug: | |
53 attr_list = ' '.join('%s="%s"' % kv for kv in attrs.items()) | |
54 print ("Starting parsing of element %s with attributes %r" % | |
55 (name, attr_list or '(none)')) | |
56 | |
57 typeattr = attrs.get('type') | |
58 node = mapping.ElementToClass(name, typeattr)() | |
59 | |
60 if self.stack: | |
61 self.stack[-1].AddChild(node) | |
62 node.StartParsing(name, self.stack[-1]) | |
63 else: | |
64 assert self.root is None | |
65 self.root = node | |
66 if isinstance(self.root, misc.GritNode): | |
67 if self.target_platform: | |
68 self.root.SetTargetPlatform(self.target_platform) | |
69 node.StartParsing(name, None) | |
70 if self.defines: | |
71 node.SetDefines(self.defines) | |
72 self.stack.append(node) | |
73 | |
74 for attr, attrval in attrs.items(): | |
75 node.HandleAttribute(attr, attrval) | |
76 | |
77 def endElement(self, name): | |
78 if self.ignore_depth: | |
79 self.ignore_depth -= 1 | |
80 return | |
81 | |
82 if name == 'part': | |
83 partnode = self.stack[-1] | |
84 partnode.started_inclusion = True | |
85 # Add the contents of the sub-grd file as children of the <part> node. | |
86 partname = partnode.GetInputPath() | |
87 if os.path.dirname(partname): | |
88 # TODO(benrg): Remove this limitation. (The problem is that GRIT | |
89 # assumes that files referenced from the GRD file are relative to | |
90 # a path stored in the root <grit> node.) | |
91 raise exception.GotPathExpectedFilenameOnly() | |
92 partname = os.path.join(self.dir, partname) | |
93 # Exceptions propagate to the handler in grd_reader.Parse(). | |
94 xml.sax.parse(partname, GrdPartContentHandler(self)) | |
95 | |
96 if self.debug: | |
97 print "End parsing of element %s" % name | |
98 self.stack.pop().EndParsing() | |
99 | |
100 if name == self.stop_after: | |
101 raise StopParsingException() | |
102 | |
103 def characters(self, content): | |
104 if self.ignore_depth == 0: | |
105 if self.stack[-1]: | |
106 self.stack[-1].AppendContent(content) | |
107 | |
108 def ignorableWhitespace(self, whitespace): | |
109 # TODO(joi) This is not supported by expat. Should use a different XML par
ser? | |
110 pass | |
111 | |
112 | |
113 class GrdPartContentHandler(xml.sax.handler.ContentHandler): | |
114 def __init__(self, parent): | |
115 self.parent = parent | |
116 self.depth = 0 | |
117 | |
118 def startElement(self, name, attrs): | |
119 if self.depth: | |
120 self.parent.startElement(name, attrs) | |
121 else: | |
122 if name != 'grit-part': | |
123 raise exception.MissingElement("root tag must be <grit-part>") | |
124 if attrs: | |
125 raise exception.UnexpectedAttribute( | |
126 "<grit-part> tag must not have attributes") | |
127 self.depth += 1 | |
128 | |
129 def endElement(self, name): | |
130 self.depth -= 1 | |
131 if self.depth: | |
132 self.parent.endElement(name) | |
133 | |
134 def characters(self, content): | |
135 self.parent.characters(content) | |
136 | |
137 def ignorableWhitespace(self, whitespace): | |
138 self.parent.ignorableWhitespace(whitespace) | |
139 | |
140 | |
141 def Parse(filename_or_stream, dir=None, stop_after=None, first_ids_file=None, | |
142 debug=False, defines=None, tags_to_ignore=None, target_platform=None): | |
143 '''Parses a GRD file into a tree of nodes (from grit.node). | |
144 | |
145 If filename_or_stream is a stream, 'dir' should point to the directory | |
146 notionally containing the stream (this feature is only used in unit tests). | |
147 | |
148 If 'stop_after' is provided, the parsing will stop once the first node | |
149 with this name has been fully parsed (including all its contents). | |
150 | |
151 If 'debug' is true, lots of information about the parsing events will be | |
152 printed out during parsing of the file. | |
153 | |
154 If 'first_ids_file' is non-empty, it is used to override the setting for the | |
155 first_ids_file attribute of the <grit> root node. Note that the first_ids_file | |
156 parameter should be relative to the cwd, even though the first_ids_file | |
157 attribute of the <grit> node is relative to the grd file. | |
158 | |
159 If 'target_platform' is set, this is used to determine the target | |
160 platform of builds, instead of using |sys.platform|. | |
161 | |
162 Args: | |
163 filename_or_stream: './bla.xml' | |
164 dir: None (if filename_or_stream is a filename) or '.' | |
165 stop_after: 'inputs' | |
166 first_ids_file: 'GRIT_DIR/../gritsettings/resource_ids' | |
167 debug: False | |
168 defines: dictionary of defines, like {'chromeos': '1'} | |
169 target_platform: None or the value that would be returned by sys.platform | |
170 on your target platform. | |
171 | |
172 Return: | |
173 Subclass of grit.node.base.Node | |
174 | |
175 Throws: | |
176 grit.exception.Parsing | |
177 ''' | |
178 | |
179 if dir is None and isinstance(filename_or_stream, types.StringType): | |
180 dir = util.dirname(filename_or_stream) | |
181 | |
182 handler = GrdContentHandler(stop_after=stop_after, debug=debug, dir=dir, | |
183 defines=defines, tags_to_ignore=tags_to_ignore, | |
184 target_platform=target_platform) | |
185 try: | |
186 xml.sax.parse(filename_or_stream, handler) | |
187 except StopParsingException: | |
188 assert stop_after | |
189 pass | |
190 except: | |
191 if not debug: | |
192 print "parse exception: run GRIT with the -x flag to debug .grd problems" | |
193 raise | |
194 | |
195 if handler.root.name != 'grit': | |
196 raise exception.MissingElement("root tag must be <grit>") | |
197 | |
198 if hasattr(handler.root, 'SetOwnDir'): | |
199 # Fix up the base_dir so it is relative to the input file. | |
200 assert dir is not None | |
201 handler.root.SetOwnDir(dir) | |
202 | |
203 if isinstance(handler.root, misc.GritNode): | |
204 if first_ids_file: | |
205 # Make the path to the first_ids_file relative to the grd file, | |
206 # unless it begins with GRIT_DIR. | |
207 GRIT_DIR_PREFIX = 'GRIT_DIR' | |
208 if not (first_ids_file.startswith(GRIT_DIR_PREFIX) | |
209 and first_ids_file[len(GRIT_DIR_PREFIX)] in ['/', '\\']): | |
210 rel_dir = os.path.relpath(os.getcwd(), dir) | |
211 first_ids_file = util.normpath(os.path.join(rel_dir, first_ids_file)) | |
212 handler.root.attrs['first_ids_file'] = first_ids_file | |
213 # Assign first ids to the nodes that don't have them. | |
214 handler.root.AssignFirstIds(filename_or_stream, defines) | |
215 | |
216 return handler.root | |
217 | |
218 | |
219 if __name__ == '__main__': | |
220 util.ChangeStdoutEncoding() | |
221 print unicode(Parse(sys.argv[1])) | |
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