1 files changed, 219 insertions, 0 deletions
diff --git a/grc/converter/block.py b/grc/converter/block.py
new file mode 100644
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+++ b/grc/converter/block.py
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+# Copyright 2016 Free Software Foundation, Inc.
+# This file is part of GNU Radio
+#
+# GNU Radio Companion is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by the
+# Free Software Foundation; either version 2 of the License, or (at your
+# option) any later version.
+#
+# GNU Radio Companion is distributed in the hope that it will be useful, but
+# WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+# FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
+# details.
+#
+# You should have received a copy of the GNU General Public License along with
+# this program; if not, write to the Free Software Foundation, Inc.,
+# 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
+"""
+Converter for legacy block definitions in XML format
+
+- Cheetah expressions that can not be converted are passed to Cheetah for now
+- Instead of generating a Block subclass directly a string representation is
+  used and evaluated. This is slower / lamer but allows us to show the user
+  how a converted definition would look like
+"""
+
+from __future__ import absolute_import, division, print_function
+
+from collections import OrderedDict, defaultdict
+from itertools import chain
+
+from ..core.io import yaml
+from . import cheetah_converter, xml
+
+current_file_format = 1
+reserved_block_keys = ('import', )  # todo: add more keys
+
+
+def from_xml(filename):
+    """Load block description from xml file"""
+    element, version_info = xml.load(filename, 'block.dtd')
+
+    try:
+        data = convert_block_xml(element)
+    except NameError:
+        raise ValueError('Conversion failed', filename)
+
+    return data
+
+
+def dump(data, stream):
+    out = yaml.dump(data)
+
+    replace = [
+        ('parameters:', '\nparameters:'),
+        ('inputs:', '\ninputs:'),
+        ('outputs:', '\noutputs:'),
+        ('templates:', '\ntemplates:'),
+        ('documentation:', '\ndocumentation:'),
+        ('file_format:', '\nfile_format:'),
+    ]
+    for r in replace:
+        out = out.replace(*r)
+    prefix = '# auto-generated by grc.converter\n\n'
+    stream.write(prefix + out)
+
+
+no_value = object()
+dummy = cheetah_converter.DummyConverter()
+
+
+def convert_block_xml(node):
+    converter = cheetah_converter.Converter(names={
+        param_node.findtext('key'): {
+            opt_node.text.split(':')[0]
+            for opt_node in next(param_node.iterfind('option'), param_node).iterfind('opt')
+        } for param_node in node.iterfind('param')
+    })
+
+    block_id = node.findtext('key')
+    if block_id in reserved_block_keys:
+        block_id += '_'
+
+    data = OrderedDict()
+    data['id'] = block_id
+    data['label'] = node.findtext('name') or no_value
+    data['category'] = node.findtext('category') or no_value
+    data['flags'] = node.findtext('flags') or no_value
+
+    data['parameters'] = [convert_param_xml(param_node, converter.to_python_dec)
+                          for param_node in node.iterfind('param')] or no_value
+    # data['params'] = {p.pop('key'): p for p in data['params']}
+
+    data['inputs'] = [convert_port_xml(port_node, converter.to_python_dec)
+                      for port_node in node.iterfind('sink')] or no_value
+
+    data['outputs'] = [convert_port_xml(port_node, converter.to_python_dec)
+                       for port_node in node.iterfind('source')] or no_value
+
+    data['checks'] = [converter.to_python_dec(check_node.text)
+                      for check_node in node.iterfind('checks')] or no_value
+    data['value'] = (
+        converter.to_python_dec(node.findtext('var_value')) or
+        ('${ value }' if block_id.startswith('variable') else no_value)
+    )
+
+    data['templates'] = convert_templates(node, converter.to_mako, block_id) or no_value
+
+    docs = node.findtext('doc')
+    if docs:
+        docs = docs.strip().replace('\\\n', '')
+        data['documentation'] = yaml.MultiLineString(docs)
+
+    data['file_format'] = current_file_format
+
+    data = OrderedDict((key, value) for key, value in data.items() if value is not no_value)
+    auto_hide_params_for_item_sizes(data)
+
+    return data
+
+
+def auto_hide_params_for_item_sizes(data):
+    item_size_templates = []
+    vlen_templates = []
+    for port in chain(*[data.get(direction, []) for direction in ['inputs', 'outputs']]):
+        for key in ['dtype', 'multiplicity']:
+            item_size_templates.append(str(port.get(key, '')))
+        vlen_templates.append(str(port.get('vlen', '')))
+    item_size_templates = ' '.join(value for value in item_size_templates if '${' in value)
+    vlen_templates = ' '.join(value for value in vlen_templates if '${' in value)
+
+    for param in data.get('parameters', []):
+        if param['id'] in item_size_templates:
+            param.setdefault('hide', 'part')
+        if param['id'] in vlen_templates:
+            param.setdefault('hide', "${ 'part' if vlen == 1 else 'none' }")
+
+
+def convert_templates(node, convert, block_id=''):
+    templates = OrderedDict()
+
+    imports = '\n'.join(convert(import_node.text)
+                        for import_node in node.iterfind('import'))
+    if '\n' in imports:
+        imports = yaml.MultiLineString(imports)
+    templates['imports'] = imports or no_value
+
+    templates['var_make'] = convert(node.findtext('var_make') or '') or no_value
+
+    make = convert(node.findtext('make') or '')
+    if make:
+        check_mako_template(block_id, make)
+    if '\n' in make:
+        make = yaml.MultiLineString(make)
+    templates['make'] = make or no_value
+
+    templates['callbacks'] = [
+         convert(cb_node.text) for cb_node in node.iterfind('callback')
+    ] or no_value
+
+    return OrderedDict((key, value) for key, value in templates.items() if value is not no_value)
+
+
+def convert_param_xml(node, convert):
+    param = OrderedDict()
+    param['id'] = node.findtext('key').strip()
+    param['label'] = node.findtext('name').strip()
+    param['category'] = node.findtext('tab') or no_value
+
+    param['dtype'] = convert(node.findtext('type') or '')
+    param['default'] = node.findtext('value') or no_value
+
+    options = yaml.ListFlowing(on.findtext('key') for on in node.iterfind('option'))
+    option_labels = yaml.ListFlowing(on.findtext('name') for on in node.iterfind('option'))
+    param['options'] = options or no_value
+    if not all(str(o).title() == l for o, l in zip(options, option_labels)):
+        param['option_labels'] = option_labels
+
+    attributes = defaultdict(yaml.ListFlowing)
+    for option_n in node.iterfind('option'):
+        for opt_n in option_n.iterfind('opt'):
+            key, value = opt_n.text.split(':', 2)
+            attributes[key].append(value)
+    param['option_attributes'] = dict(attributes) or no_value
+
+    param['hide'] = convert(node.findtext('hide')) or no_value
+
+    return OrderedDict((key, value) for key, value in param.items() if value is not no_value)
+
+
+def convert_port_xml(node, convert):
+    port = OrderedDict()
+    label = node.findtext('name')
+    # default values:
+    port['label'] = label if label not in ('in', 'out') else no_value
+
+    dtype = convert(node.findtext('type'))
+    # TODO: detect dyn message ports
+    port['domain'] = domain = 'message' if dtype == 'message' else 'stream'
+    if domain == 'message':
+        port['id'], port['label'] = label, no_value
+    else:
+        port['dtype'] = dtype
+        vlen = node.findtext('vlen')
+        port['vlen'] = int(vlen) if vlen and vlen.isdigit() else convert(vlen) or no_value
+
+    port['multiplicity'] = convert(node.findtext('nports')) or no_value
+    port['optional'] = bool(node.findtext('optional')) or no_value
+    port['hide'] = convert(node.findtext('hide')) or no_value
+
+    return OrderedDict((key, value) for key, value in port.items() if value is not no_value)
+
+
+def check_mako_template(block_id, expr):
+    import sys
+    from mako.template import Template
+    try:
+        Template(expr)
+    except Exception as error:
+        print(block_id, expr, type(error), error, '', sep='\n', file=sys.stderr)