scripts/qapi/introspect.py

   1 """
   2 QAPI introspection generator
   3
   4 Copyright (C) 2015-2018 Red Hat, Inc.
   5
   6 Authors:
   7  Markus Armbruster <armbru@redhat.com>
   8
   9 This work is licensed under the terms of the GNU GPL, version 2.
  10 See the COPYING file in the top-level directory.
  11 """
  12
  13 from qapi.common import *
  14 from qapi.gen import QAPISchemaMonolithicCVisitor
  15 from qapi.schema import (QAPISchemaArrayType, QAPISchemaBuiltinType,
  16                          QAPISchemaType)
  17
  18
  19 def _make_tree(obj, ifcond, features, extra=None):
  20     if extra is None:
  21         extra = {}
  22     if ifcond:
  23         extra['if'] = ifcond
  24     if features:
  25         obj['features'] = [(f.name, {'if': f.ifcond}) for f in features]
  26     if extra:
  27         return (obj, extra)
  28     return obj
  29
  30
  31 def _tree_to_qlit(obj, level=0, suppress_first_indent=False):
  32
  33     def indent(level):
  34         return level * 4 * ' '
  35
  36     if isinstance(obj, tuple):
  37         ifobj, extra = obj
  38         ifcond = extra.get('if')
  39         comment = extra.get('comment')
  40         ret = ''
  41         if comment:
  42             ret += indent(level) + '/* %s */\n' % comment
  43         if ifcond:
  44             ret += gen_if(ifcond)
  45         ret += _tree_to_qlit(ifobj, level)
  46         if ifcond:
  47             ret += '\n' + gen_endif(ifcond)
  48         return ret
  49
  50     ret = ''
  51     if not suppress_first_indent:
  52         ret += indent(level)
  53     if obj is None:
  54         ret += 'QLIT_QNULL'
  55     elif isinstance(obj, str):
  56         ret += 'QLIT_QSTR(' + to_c_string(obj) + ')'
  57     elif isinstance(obj, list):
  58         elts = [_tree_to_qlit(elt, level + 1).strip('\n')
  59                 for elt in obj]
  60         elts.append(indent(level + 1) + "{}")
  61         ret += 'QLIT_QLIST(((QLitObject[]) {\n'
  62         ret += '\n'.join(elts) + '\n'
  63         ret += indent(level) + '}))'
  64     elif isinstance(obj, dict):
  65         elts = []
  66         for key, value in sorted(obj.items()):
  67             elts.append(indent(level + 1) + '{ %s, %s }' %
  68                         (to_c_string(key),
  69                          _tree_to_qlit(value, level + 1, True)))
  70         elts.append(indent(level + 1) + '{}')
  71         ret += 'QLIT_QDICT(((QLitDictEntry[]) {\n'
  72         ret += ',\n'.join(elts) + '\n'
  73         ret += indent(level) + '}))'
  74     elif isinstance(obj, bool):
  75         ret += 'QLIT_QBOOL(%s)' % ('true' if obj else 'false')
  76     else:
  77         assert False                # not implemented
  78     if level > 0:
  79         ret += ','
  80     return ret
  81
  82
  83 def to_c_string(string):
  84     return '"' + string.replace('\\', r'\\').replace('"', r'\"') + '"'
  85
  86
  87 class QAPISchemaGenIntrospectVisitor(QAPISchemaMonolithicCVisitor):
  88
  89     def __init__(self, prefix, unmask):
  90         super().__init__(
  91             prefix, 'qapi-introspect',
  92             ' * QAPI/QMP schema introspection', __doc__)
  93         self._unmask = unmask
  94         self._schema = None
  95         self._trees = []
  96         self._used_types = []
  97         self._name_map = {}
  98         self._genc.add(mcgen('''
  99 #include "qemu/osdep.h"
 100 #include "%(prefix)sqapi-introspect.h"
 101
 102 ''',
 103                              prefix=prefix))
 104
 105     def visit_begin(self, schema):
 106         self._schema = schema
 107
 108     def visit_end(self):
 109         # visit the types that are actually used
 110         for typ in self._used_types:
 111             typ.visit(self)
 112         # generate C
 113         name = c_name(self._prefix, protect=False) + 'qmp_schema_qlit'
 114         self._genh.add(mcgen('''
 115 #include "qapi/qmp/qlit.h"
 116
 117 extern const QLitObject %(c_name)s;
 118 ''',
 119                              c_name=c_name(name)))
 120         self._genc.add(mcgen('''
 121 const QLitObject %(c_name)s = %(c_string)s;
 122 ''',
 123                              c_name=c_name(name),
 124                              c_string=_tree_to_qlit(self._trees)))
 125         self._schema = None
 126         self._trees = []
 127         self._used_types = []
 128         self._name_map = {}
 129
 130     def visit_needed(self, entity):
 131         # Ignore types on first pass; visit_end() will pick up used types
 132         return not isinstance(entity, QAPISchemaType)
 133
 134     def _name(self, name):
 135         if self._unmask:
 136             return name
 137         if name not in self._name_map:
 138             self._name_map[name] = '%d' % len(self._name_map)
 139         return self._name_map[name]
 140
 141     def _use_type(self, typ):
 142         # Map the various integer types to plain int
 143         if typ.json_type() == 'int':
 144             typ = self._schema.lookup_type('int')
 145         elif (isinstance(typ, QAPISchemaArrayType) and
 146               typ.element_type.json_type() == 'int'):
 147             typ = self._schema.lookup_type('intList')
 148         # Add type to work queue if new
 149         if typ not in self._used_types:
 150             self._used_types.append(typ)
 151         # Clients should examine commands and events, not types.  Hide
 152         # type names as integers to reduce the temptation.  Also, it
 153         # saves a few characters on the wire.
 154         if isinstance(typ, QAPISchemaBuiltinType):
 155             return typ.name
 156         if isinstance(typ, QAPISchemaArrayType):
 157             return '[' + self._use_type(typ.element_type) + ']'
 158         return self._name(typ.name)
 159
 160     def _gen_tree(self, name, mtype, obj, ifcond, features):
 161         extra = None
 162         if mtype not in ('command', 'event', 'builtin', 'array'):
 163             if not self._unmask:
 164                 # Output a comment to make it easy to map masked names
 165                 # back to the source when reading the generated output.
 166                 extra = {'comment': '"%s" = %s' % (self._name(name), name)}
 167             name = self._name(name)
 168         obj['name'] = name
 169         obj['meta-type'] = mtype
 170         self._trees.append(_make_tree(obj, ifcond, features, extra))
 171
 172     def _gen_member(self, member):
 173         obj = {'name': member.name, 'type': self._use_type(member.type)}
 174         if member.optional:
 175             obj['default'] = None
 176         return _make_tree(obj, member.ifcond, member.features)
 177
 178     def _gen_variants(self, tag_name, variants):
 179         return {'tag': tag_name,
 180                 'variants': [self._gen_variant(v) for v in variants]}
 181
 182     def _gen_variant(self, variant):
 183         obj = {'case': variant.name, 'type': self._use_type(variant.type)}
 184         return _make_tree(obj, variant.ifcond, None)
 185
 186     def visit_builtin_type(self, name, info, json_type):
 187         self._gen_tree(name, 'builtin', {'json-type': json_type}, [], None)
 188
 189     def visit_enum_type(self, name, info, ifcond, features, members, prefix):
 190         self._gen_tree(name, 'enum',
 191                        {'values': [_make_tree(m.name, m.ifcond, None)
 192                                    for m in members]},
 193                        ifcond, features)
 194
 195     def visit_array_type(self, name, info, ifcond, element_type):
 196         element = self._use_type(element_type)
 197         self._gen_tree('[' + element + ']', 'array', {'element-type': element},
 198                        ifcond, None)
 199
 200     def visit_object_type_flat(self, name, info, ifcond, features,
 201                                members, variants):
 202         obj = {'members': [self._gen_member(m) for m in members]}
 203         if variants:
 204             obj.update(self._gen_variants(variants.tag_member.name,
 205                                           variants.variants))
 206
 207         self._gen_tree(name, 'object', obj, ifcond, features)
 208
 209     def visit_alternate_type(self, name, info, ifcond, features, variants):
 210         self._gen_tree(name, 'alternate',
 211                        {'members': [
 212                            _make_tree({'type': self._use_type(m.type)},
 213                                       m.ifcond, None)
 214                            for m in variants.variants]},
 215                        ifcond, features)
 216
 217     def visit_command(self, name, info, ifcond, features,
 218                       arg_type, ret_type, gen, success_response, boxed,
 219                       allow_oob, allow_preconfig):
 220         arg_type = arg_type or self._schema.the_empty_object_type
 221         ret_type = ret_type or self._schema.the_empty_object_type
 222         obj = {'arg-type': self._use_type(arg_type),
 223                'ret-type': self._use_type(ret_type)}
 224         if allow_oob:
 225             obj['allow-oob'] = allow_oob
 226         self._gen_tree(name, 'command', obj, ifcond, features)
 227
 228     def visit_event(self, name, info, ifcond, features, arg_type, boxed):
 229         arg_type = arg_type or self._schema.the_empty_object_type
 230         self._gen_tree(name, 'event', {'arg-type': self._use_type(arg_type)},
 231                        ifcond, features)
 232
 233
 234 def gen_introspect(schema, output_dir, prefix, opt_unmask):
 235     vis = QAPISchemaGenIntrospectVisitor(prefix, opt_unmask)
 236     schema.visit(vis)
 237     vis.write(output_dir)