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 .common import (
  14     c_name,
  15     gen_endif,
  16     gen_if,
  17     mcgen,
  18 )
  19 from .gen import QAPISchemaMonolithicCVisitor
  20 from .schema import (
  21     QAPISchemaArrayType,
  22     QAPISchemaBuiltinType,
  23     QAPISchemaType,
  24 )
  25
  26
  27 def _make_tree(obj, ifcond, features, extra=None):
  28     if extra is None:
  29         extra = {}
  30     if ifcond:
  31         extra['if'] = ifcond
  32     if features:
  33         obj['features'] = [(f.name, {'if': f.ifcond}) for f in features]
  34     if extra:
  35         return (obj, extra)
  36     return obj
  37
  38
  39 def _tree_to_qlit(obj, level=0, suppress_first_indent=False):
  40
  41     def indent(level):
  42         return level * 4 * ' '
  43
  44     if isinstance(obj, tuple):
  45         ifobj, extra = obj
  46         ifcond = extra.get('if')
  47         comment = extra.get('comment')
  48         ret = ''
  49         if comment:
  50             ret += indent(level) + '/* %s */\n' % comment
  51         if ifcond:
  52             ret += gen_if(ifcond)
  53         ret += _tree_to_qlit(ifobj, level)
  54         if ifcond:
  55             ret += '\n' + gen_endif(ifcond)
  56         return ret
  57
  58     ret = ''
  59     if not suppress_first_indent:
  60         ret += indent(level)
  61     if obj is None:
  62         ret += 'QLIT_QNULL'
  63     elif isinstance(obj, str):
  64         ret += 'QLIT_QSTR(' + to_c_string(obj) + ')'
  65     elif isinstance(obj, list):
  66         elts = [_tree_to_qlit(elt, level + 1).strip('\n')
  67                 for elt in obj]
  68         elts.append(indent(level + 1) + "{}")
  69         ret += 'QLIT_QLIST(((QLitObject[]) {\n'
  70         ret += '\n'.join(elts) + '\n'
  71         ret += indent(level) + '}))'
  72     elif isinstance(obj, dict):
  73         elts = []
  74         for key, value in sorted(obj.items()):
  75             elts.append(indent(level + 1) + '{ %s, %s }' %
  76                         (to_c_string(key),
  77                          _tree_to_qlit(value, level + 1, True)))
  78         elts.append(indent(level + 1) + '{}')
  79         ret += 'QLIT_QDICT(((QLitDictEntry[]) {\n'
  80         ret += ',\n'.join(elts) + '\n'
  81         ret += indent(level) + '}))'
  82     elif isinstance(obj, bool):
  83         ret += 'QLIT_QBOOL(%s)' % ('true' if obj else 'false')
  84     else:
  85         assert False                # not implemented
  86     if level > 0:
  87         ret += ','
  88     return ret
  89
  90
  91 def to_c_string(string):
  92     return '"' + string.replace('\\', r'\\').replace('"', r'\"') + '"'
  93
  94
  95 class QAPISchemaGenIntrospectVisitor(QAPISchemaMonolithicCVisitor):
  96
  97     def __init__(self, prefix, unmask):
  98         super().__init__(
  99             prefix, 'qapi-introspect',
 100             ' * QAPI/QMP schema introspection', __doc__)
 101         self._unmask = unmask
 102         self._schema = None
 103         self._trees = []
 104         self._used_types = []
 105         self._name_map = {}
 106         self._genc.add(mcgen('''
 107 #include "qemu/osdep.h"
 108 #include "%(prefix)sqapi-introspect.h"
 109
 110 ''',
 111                              prefix=prefix))
 112
 113     def visit_begin(self, schema):
 114         self._schema = schema
 115
 116     def visit_end(self):
 117         # visit the types that are actually used
 118         for typ in self._used_types:
 119             typ.visit(self)
 120         # generate C
 121         name = c_name(self._prefix, protect=False) + 'qmp_schema_qlit'
 122         self._genh.add(mcgen('''
 123 #include "qapi/qmp/qlit.h"
 124
 125 extern const QLitObject %(c_name)s;
 126 ''',
 127                              c_name=c_name(name)))
 128         self._genc.add(mcgen('''
 129 const QLitObject %(c_name)s = %(c_string)s;
 130 ''',
 131                              c_name=c_name(name),
 132                              c_string=_tree_to_qlit(self._trees)))
 133         self._schema = None
 134         self._trees = []
 135         self._used_types = []
 136         self._name_map = {}
 137
 138     def visit_needed(self, entity):
 139         # Ignore types on first pass; visit_end() will pick up used types
 140         return not isinstance(entity, QAPISchemaType)
 141
 142     def _name(self, name):
 143         if self._unmask:
 144             return name
 145         if name not in self._name_map:
 146             self._name_map[name] = '%d' % len(self._name_map)
 147         return self._name_map[name]
 148
 149     def _use_type(self, typ):
 150         # Map the various integer types to plain int
 151         if typ.json_type() == 'int':
 152             typ = self._schema.lookup_type('int')
 153         elif (isinstance(typ, QAPISchemaArrayType) and
 154               typ.element_type.json_type() == 'int'):
 155             typ = self._schema.lookup_type('intList')
 156         # Add type to work queue if new
 157         if typ not in self._used_types:
 158             self._used_types.append(typ)
 159         # Clients should examine commands and events, not types.  Hide
 160         # type names as integers to reduce the temptation.  Also, it
 161         # saves a few characters on the wire.
 162         if isinstance(typ, QAPISchemaBuiltinType):
 163             return typ.name
 164         if isinstance(typ, QAPISchemaArrayType):
 165             return '[' + self._use_type(typ.element_type) + ']'
 166         return self._name(typ.name)
 167
 168     def _gen_tree(self, name, mtype, obj, ifcond, features):
 169         extra = None
 170         if mtype not in ('command', 'event', 'builtin', 'array'):
 171             if not self._unmask:
 172                 # Output a comment to make it easy to map masked names
 173                 # back to the source when reading the generated output.
 174                 extra = {'comment': '"%s" = %s' % (self._name(name), name)}
 175             name = self._name(name)
 176         obj['name'] = name
 177         obj['meta-type'] = mtype
 178         self._trees.append(_make_tree(obj, ifcond, features, extra))
 179
 180     def _gen_member(self, member):
 181         obj = {'name': member.name, 'type': self._use_type(member.type)}
 182         if member.optional:
 183             obj['default'] = None
 184         return _make_tree(obj, member.ifcond, member.features)
 185
 186     def _gen_variants(self, tag_name, variants):
 187         return {'tag': tag_name,
 188                 'variants': [self._gen_variant(v) for v in variants]}
 189
 190     def _gen_variant(self, variant):
 191         obj = {'case': variant.name, 'type': self._use_type(variant.type)}
 192         return _make_tree(obj, variant.ifcond, None)
 193
 194     def visit_builtin_type(self, name, info, json_type):
 195         self._gen_tree(name, 'builtin', {'json-type': json_type}, [], None)
 196
 197     def visit_enum_type(self, name, info, ifcond, features, members, prefix):
 198         self._gen_tree(name, 'enum',
 199                        {'values': [_make_tree(m.name, m.ifcond, None)
 200                                    for m in members]},
 201                        ifcond, features)
 202
 203     def visit_array_type(self, name, info, ifcond, element_type):
 204         element = self._use_type(element_type)
 205         self._gen_tree('[' + element + ']', 'array', {'element-type': element},
 206                        ifcond, None)
 207
 208     def visit_object_type_flat(self, name, info, ifcond, features,
 209                                members, variants):
 210         obj = {'members': [self._gen_member(m) for m in members]}
 211         if variants:
 212             obj.update(self._gen_variants(variants.tag_member.name,
 213                                           variants.variants))
 214
 215         self._gen_tree(name, 'object', obj, ifcond, features)
 216
 217     def visit_alternate_type(self, name, info, ifcond, features, variants):
 218         self._gen_tree(name, 'alternate',
 219                        {'members': [
 220                            _make_tree({'type': self._use_type(m.type)},
 221                                       m.ifcond, None)
 222                            for m in variants.variants]},
 223                        ifcond, features)
 224
 225     def visit_command(self, name, info, ifcond, features,
 226                       arg_type, ret_type, gen, success_response, boxed,
 227                       allow_oob, allow_preconfig, coroutine):
 228         arg_type = arg_type or self._schema.the_empty_object_type
 229         ret_type = ret_type or self._schema.the_empty_object_type
 230         obj = {'arg-type': self._use_type(arg_type),
 231                'ret-type': self._use_type(ret_type)}
 232         if allow_oob:
 233             obj['allow-oob'] = allow_oob
 234         self._gen_tree(name, 'command', obj, ifcond, features)
 235
 236     def visit_event(self, name, info, ifcond, features, arg_type, boxed):
 237         arg_type = arg_type or self._schema.the_empty_object_type
 238         self._gen_tree(name, 'event', {'arg-type': self._use_type(arg_type)},
 239                        ifcond, features)
 240
 241
 242 def gen_introspect(schema, output_dir, prefix, opt_unmask):
 243     vis = QAPISchemaGenIntrospectVisitor(prefix, opt_unmask)
 244     schema.visit(vis)
 245     vis.write(output_dir)