#!/usr/bin/env python3
# Copyright 2012 The Chromium Authors
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.
'''Class for reading GRD files into memory, without processing them.
'''
import os.path
import sys
import xml.sax
import xml.sax.handler
from grit import exception
from grit import util
from grit.node import mapping
from grit.node import misc
class StopParsingException(Exception):
'''An exception used to stop parsing.'''
pass
class GrdContentHandler(xml.sax.handler.ContentHandler):
def __init__(self, stop_after, debug, dir, defines, tags_to_ignore,
target_platform, source, skip_validation_checks):
# Invariant of data:
# 'root' is the root of the parse tree being created, or None if we haven't
# parsed out any elements.
# 'stack' is the a stack of elements that we push new nodes onto and
# pop from when they finish parsing, or [] if we are not currently parsing.
# 'stack[-1]' is the top of the stack.
self.root = None
self.stack = []
self.stop_after = stop_after
self.debug = debug
self.dir = dir
self.defines = defines
self.tags_to_ignore = tags_to_ignore or set()
self.ignore_depth = 0
self.target_platform = target_platform
self.source = source
self.skip_validation_checks = skip_validation_checks
def startElement(self, name, attrs):
if self.ignore_depth or name in self.tags_to_ignore:
if self.debug and self.ignore_depth == 0:
print("Ignoring element %s and its children" % name)
self.ignore_depth += 1
return
if self.debug:
attr_list = ' '.join('%s="%s"' % kv for kv in attrs.items())
print("Starting parsing of element %s with attributes %r" %
(name, attr_list or '(none)'))
typeattr = attrs.get('type')
node = mapping.ElementToClass(name, typeattr)()
node.source = self.source
if self.stack:
self.stack[-1].AddChild(node)
node.StartParsing(name, self.stack[-1])
else:
assert self.root is None
self.root = node
if isinstance(self.root, misc.GritNode):
if self.target_platform:
self.root.SetTargetPlatform(self.target_platform)
node.StartParsing(name, None)
if self.defines:
node.SetDefines(self.defines)
node.skip_validation_checks = self.skip_validation_checks
self.stack.append(node)
for attr, attrval in attrs.items():
node.HandleAttribute(attr, attrval)
def endElement(self, name):
if self.ignore_depth:
self.ignore_depth -= 1
return
if name == 'part':
partnode = self.stack[-1]
partnode.started_inclusion = True
# Add the contents of the sub-grd file as children of the <part> node.
partname = os.path.join(self.dir, partnode.GetInputPath())
# Check the GRDP file exists.
if not os.path.exists(partname):
raise exception.FileNotFound(partname)
# Exceptions propagate to the handler in grd_reader.Parse().
oldsource = self.source
try:
self.source = partname
xml.sax.parse(partname, GrdPartContentHandler(self))
finally:
self.source = oldsource
if self.debug:
print("End parsing of element %s" % name)
self.stack.pop().EndParsing()
if name == self.stop_after:
raise StopParsingException()
def characters(self, content):
if self.ignore_depth == 0:
if self.stack[-1]:
self.stack[-1].AppendContent(content)
def ignorableWhitespace(self, whitespace):
# TODO(joi): This is not supported by expat. Should use a different XML
# parser?
pass
class GrdPartContentHandler(xml.sax.handler.ContentHandler):
def __init__(self, parent):
self.parent = parent
self.depth = 0
def startElement(self, name, attrs):
if self.depth:
self.parent.startElement(name, attrs)
else:
if name != 'grit-part':
raise exception.MissingElement("root tag must be <grit-part>")
if attrs:
raise exception.UnexpectedAttribute(
"<grit-part> tag must not have attributes")
self.depth += 1
def endElement(self, name):
self.depth -= 1
if self.depth:
self.parent.endElement(name)
def characters(self, content):
self.parent.characters(content)
def ignorableWhitespace(self, whitespace):
self.parent.ignorableWhitespace(whitespace)
def Parse(filename_or_stream,
dir=None,
stop_after=None,
first_ids_file=None,
debug=False,
defines=None,
tags_to_ignore=None,
target_platform=None,
predetermined_ids_file=None,
skip_validation_checks=False):
'''Parses a GRD file into a tree of nodes (from grit.node).
If filename_or_stream is a stream, 'dir' should point to the directory
notionally containing the stream (this feature is only used in unit tests).
If 'stop_after' is provided, the parsing will stop once the first node
with this name has been fully parsed (including all its contents).
If 'debug' is true, lots of information about the parsing events will be
printed out during parsing of the file.
If 'first_ids_file' is non-empty, it is used to override the setting for the
first_ids_file attribute of the <grit> root node. Note that the first_ids_file
parameter should be relative to the cwd, even though the first_ids_file
attribute of the <grit> node is relative to the grd file.
If 'target_platform' is set, this is used to determine the target
platform of builds, instead of using |sys.platform|.
Args:
filename_or_stream: './bla.xml'
dir: None (if filename_or_stream is a filename) or '.'
stop_after: 'inputs'
first_ids_file: 'GRIT_DIR/../gritsettings/resource_ids'
debug: False
defines: dictionary of defines, like {'chromeos': '1'}
target_platform: None or the value that would be returned by sys.platform
on your target platform.
predetermined_ids_file: File path to a file containing a pre-determined
mapping from resource names to resource ids which will be used to assign
resource ids to those resources.
skip_validation_checks: Whether to skip any validation after successfull
parsing, for example uniqueness of IDs, or that all variables encountered
in <if expr> statements are defined.
Return:
Subclass of grit.node.base.Node
Throws:
grit.exception.Parsing
'''
if isinstance(filename_or_stream, str):
source = filename_or_stream
if dir is None:
dir = util.dirname(filename_or_stream)
else:
source = None
handler = GrdContentHandler(stop_after=stop_after,
debug=debug,
dir=dir,
defines=defines,
tags_to_ignore=tags_to_ignore,
target_platform=target_platform,
source=source,
skip_validation_checks=skip_validation_checks)
try:
xml.sax.parse(filename_or_stream, handler)
except StopParsingException:
assert stop_after
pass
except:
if not debug:
print("parse exception: run GRIT with the -x flag to debug .grd problems")
raise
if handler.root.name != 'grit':
raise exception.MissingElement("root tag must be <grit>")
if hasattr(handler.root, 'SetOwnDir'):
# Fix up the base_dir so it is relative to the input file.
assert dir is not None
handler.root.SetOwnDir(dir)
if isinstance(handler.root, misc.GritNode):
handler.root.SetPredeterminedIdsFile(predetermined_ids_file)
if first_ids_file:
# Make the path to the first_ids_file relative to the grd file,
# unless it begins with GRIT_DIR.
GRIT_DIR_PREFIX = 'GRIT_DIR'
if not (first_ids_file.startswith(GRIT_DIR_PREFIX)
and first_ids_file[len(GRIT_DIR_PREFIX)] in ['/', '\\']):
rel_dir = os.path.relpath(os.getcwd(), dir)
first_ids_file = util.normpath(os.path.join(rel_dir, first_ids_file))
handler.root.attrs['first_ids_file'] = first_ids_file
# Assign first ids to the nodes that don't have them.
handler.root.AssignFirstIds(filename_or_stream, defines)
return handler.root
if __name__ == '__main__':
util.ChangeStdoutEncoding()
print(str(Parse(sys.argv[1])))
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