# 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.
import json
import struct_generator
def _JSONToCString16(json_string_literal):
"""Converts a JSON string literal to a C++ UTF-16 string literal. This is
done by converting \\u#### to \\x####.
"""
c_string_literal = json_string_literal
escape_index = c_string_literal.find('\\')
while escape_index > 0:
if c_string_literal[escape_index + 1] == 'u':
# We close the C string literal after the 4 hex digits and reopen it right
# after, otherwise the Windows compiler will sometimes try to get more
# than 4 characters in the hex string.
c_string_literal = (c_string_literal[0:escape_index + 1] + 'x' +
c_string_literal[escape_index + 2:escape_index + 6] +
'" u"' + c_string_literal[escape_index + 6:])
escape_index = c_string_literal.find('\\', escape_index + 6)
return c_string_literal
def _GenerateString(content, lines, indent=' '):
"""Generates an UTF-8 string to be included in a static structure initializer.
If content is not specified, uses NULL.
"""
if content is None:
lines.append(indent + 'NULL,')
else:
# json.dumps quotes the string and escape characters as required.
lines.append(indent + '%s,' % json.dumps(content))
def _GenerateString16(content, lines, indent=' '):
"""Generates an UTF-16 string to be included in a static structure
initializer. If content is not specified, uses NULL.
"""
if content is None:
lines.append(indent + 'NULL,')
else:
# json.dumps quotes the string and escape characters as required.
lines.append(indent + 'u%s,' % _JSONToCString16(json.dumps(content)))
def _GenerateArrayVariableName(element_name, field_name, field_name_count):
# Generates a unique variable name for an array variable.
var = 'array_%s_%s' % (element_name, field_name)
if var not in field_name_count:
field_name_count[var] = 0
return var
new_var = '%s_%d' % (var, field_name_count[var])
field_name_count[var] += 1
return new_var
def _GenerateArray(element_name, field_info, content, lines, indent,
field_name_count):
"""Generates an array to be included in a static structure initializer. If
content is not specified, uses NULL. The array is assigned to a temporary
variable which is initialized before the structure.
"""
if content is None:
lines.append(indent + 'NULL,')
lines.append(indent + '0,') # Size of the array.
return
# Create a new array variable and use it in the structure initializer.
# This prohibits nested arrays. Add a clash detection and renaming mechanism
# to solve the problem.
var = _GenerateArrayVariableName(element_name, field_info['field'],
field_name_count)
lines.append(indent + '%s,' % var)
lines.append(indent + '%s,' % len(content)) # Size of the array.
# Generate the array content.
array_lines = []
field_info['contents']['field'] = var;
array_lines.append(struct_generator.GenerateField(
field_info['contents']) + '[] = {')
for subcontent in content:
GenerateFieldContent(element_name, field_info['contents'], subcontent,
array_lines, indent, field_name_count)
array_lines.append('};')
# Prepend the generated array so it is initialized before the structure.
lines.reverse()
array_lines.reverse()
lines.extend(array_lines)
lines.reverse()
def _GenerateStruct(element_name, field_info, content, lines, indent,
field_name_count):
"""Generates a struct to be included in a static structure initializer. If
content is not specified, uses {0}.
"""
if content is None:
lines.append(indent + '{0},')
return
fields = field_info['fields']
lines.append(indent + '{')
for field in fields:
subcontent = content.get(field['field'])
GenerateFieldContent(element_name, field, subcontent, lines, ' ' + indent,
field_name_count)
lines.append(indent + '},')
def GenerateFieldContent(element_name, field_info, content, lines, indent,
field_name_count):
"""Generate the content of a field to be included in the static structure
initializer. If the field's content is not specified, uses the default value
if one exists.
"""
if content is None:
content = field_info.get('default', None)
type = field_info['type']
if type in ('int', 'enum', 'class'):
lines.append('%s%s,' % (indent, content))
elif type == 'string':
_GenerateString(content, lines, indent)
elif type == 'string16':
_GenerateString16(content, lines, indent)
elif type == 'array':
_GenerateArray(element_name, field_info, content, lines, indent,
field_name_count)
elif type == 'struct':
_GenerateStruct(element_name, field_info, content, lines, indent,
field_name_count)
else:
raise RuntimeError('Unknown field type "%s"' % type)
def GenerateElement(type_name, schema, element_name, element, field_name_count):
"""Generate the static structure initializer for one element.
"""
lines = [];
lines.append('const %s %s = {' % (type_name, element_name));
for field_info in schema:
content = element.get(field_info['field'], None)
if (content == None and not field_info.get('optional', False)):
raise RuntimeError('Mandatory field "%s" omitted in element "%s".' %
(field_info['field'], element_name))
GenerateFieldContent(element_name, field_info, content, lines, ' ',
field_name_count)
lines.append('};')
return '\n'.join(lines)
def GenerateElements(type_name, schema, description, field_name_count={}):
"""Generate the static structure initializer for all the elements in the
description['elements'] dictionary, as well as for any variables in
description['int_variables'].
"""
result = [];
for var_name, value in description.get('int_variables', {}).items():
result.append('const int %s = %s;' % (var_name, value))
result.append('')
for element_name, element in description.get('elements', {}).items():
result.append(GenerateElement(type_name, schema, element_name, element,
field_name_count))
result.append('')
return '\n'.join(result)