scripts/qapi.py

   1 #
   2 # QAPI helper library
   3 #
   4 # Copyright IBM, Corp. 2011
   5 # Copyright (c) 2013-2015 Red Hat Inc.
   6 #
   7 # Authors:
   8 #  Anthony Liguori <aliguori@us.ibm.com>
   9 #  Markus Armbruster <armbru@redhat.com>
  10 #
  11 # This work is licensed under the terms of the GNU GPL, version 2.
  12 # See the COPYING file in the top-level directory.
  13
  14 import re
  15 from ordereddict import OrderedDict
  16 import errno
  17 import getopt
  18 import os
  19 import sys
  20 import string
  21
  22 builtin_types = {
  23     'str':      'QTYPE_QSTRING',
  24     'int':      'QTYPE_QINT',
  25     'number':   'QTYPE_QFLOAT',
  26     'bool':     'QTYPE_QBOOL',
  27     'int8':     'QTYPE_QINT',
  28     'int16':    'QTYPE_QINT',
  29     'int32':    'QTYPE_QINT',
  30     'int64':    'QTYPE_QINT',
  31     'uint8':    'QTYPE_QINT',
  32     'uint16':   'QTYPE_QINT',
  33     'uint32':   'QTYPE_QINT',
  34     'uint64':   'QTYPE_QINT',
  35     'size':     'QTYPE_QINT',
  36 }
  37
  38 # Whitelist of commands allowed to return a non-dictionary
  39 returns_whitelist = [
  40     # From QMP:
  41     'human-monitor-command',
  42     'query-migrate-cache-size',
  43     'query-tpm-models',
  44     'query-tpm-types',
  45     'ringbuf-read',
  46
  47     # From QGA:
  48     'guest-file-open',
  49     'guest-fsfreeze-freeze',
  50     'guest-fsfreeze-freeze-list',
  51     'guest-fsfreeze-status',
  52     'guest-fsfreeze-thaw',
  53     'guest-get-time',
  54     'guest-set-vcpus',
  55     'guest-sync',
  56     'guest-sync-delimited',
  57
  58     # From qapi-schema-test:
  59     'user_def_cmd3',
  60 ]
  61
  62 enum_types = []
  63 struct_types = []
  64 union_types = []
  65 events = []
  66 all_names = {}
  67
  68 #
  69 # Parsing the schema into expressions
  70 #
  71
  72 def error_path(parent):
  73     res = ""
  74     while parent:
  75         res = ("In file included from %s:%d:\n" % (parent['file'],
  76                                                    parent['line'])) + res
  77         parent = parent['parent']
  78     return res
  79
  80 class QAPISchemaError(Exception):
  81     def __init__(self, schema, msg):
  82         self.fname = schema.fname
  83         self.msg = msg
  84         self.col = 1
  85         self.line = schema.line
  86         for ch in schema.src[schema.line_pos:schema.pos]:
  87             if ch == '\t':
  88                 self.col = (self.col + 7) % 8 + 1
  89             else:
  90                 self.col += 1
  91         self.info = schema.incl_info
  92
  93     def __str__(self):
  94         return error_path(self.info) + \
  95             "%s:%d:%d: %s" % (self.fname, self.line, self.col, self.msg)
  96
  97 class QAPIExprError(Exception):
  98     def __init__(self, expr_info, msg):
  99         self.info = expr_info
 100         self.msg = msg
 101
 102     def __str__(self):
 103         return error_path(self.info['parent']) + \
 104             "%s:%d: %s" % (self.info['file'], self.info['line'], self.msg)
 105
 106 class QAPISchema:
 107
 108     def __init__(self, fp, previously_included = [], incl_info = None):
 109         abs_fname = os.path.abspath(fp.name)
 110         fname = fp.name
 111         self.fname = fname
 112         previously_included.append(abs_fname)
 113         self.incl_info = incl_info
 114         self.src = fp.read()
 115         if self.src == '' or self.src[-1] != '\n':
 116             self.src += '\n'
 117         self.cursor = 0
 118         self.line = 1
 119         self.line_pos = 0
 120         self.exprs = []
 121         self.accept()
 122
 123         while self.tok != None:
 124             expr_info = {'file': fname, 'line': self.line,
 125                          'parent': self.incl_info}
 126             expr = self.get_expr(False)
 127             if isinstance(expr, dict) and "include" in expr:
 128                 if len(expr) != 1:
 129                     raise QAPIExprError(expr_info, "Invalid 'include' directive")
 130                 include = expr["include"]
 131                 if not isinstance(include, str):
 132                     raise QAPIExprError(expr_info,
 133                                         'Expected a file name (string), got: %s'
 134                                         % include)
 135                 incl_abs_fname = os.path.join(os.path.dirname(abs_fname),
 136                                               include)
 137                 # catch inclusion cycle
 138                 inf = expr_info
 139                 while inf:
 140                     if incl_abs_fname == os.path.abspath(inf['file']):
 141                         raise QAPIExprError(expr_info, "Inclusion loop for %s"
 142                                             % include)
 143                     inf = inf['parent']
 144                 # skip multiple include of the same file
 145                 if incl_abs_fname in previously_included:
 146                     continue
 147                 try:
 148                     fobj = open(incl_abs_fname, 'r')
 149                 except IOError, e:
 150                     raise QAPIExprError(expr_info,
 151                                         '%s: %s' % (e.strerror, include))
 152                 exprs_include = QAPISchema(fobj, previously_included,
 153                                            expr_info)
 154                 self.exprs.extend(exprs_include.exprs)
 155             else:
 156                 expr_elem = {'expr': expr,
 157                              'info': expr_info}
 158                 self.exprs.append(expr_elem)
 159
 160     def accept(self):
 161         while True:
 162             self.tok = self.src[self.cursor]
 163             self.pos = self.cursor
 164             self.cursor += 1
 165             self.val = None
 166
 167             if self.tok == '#':
 168                 self.cursor = self.src.find('\n', self.cursor)
 169             elif self.tok in ['{', '}', ':', ',', '[', ']']:
 170                 return
 171             elif self.tok == "'":
 172                 string = ''
 173                 esc = False
 174                 while True:
 175                     ch = self.src[self.cursor]
 176                     self.cursor += 1
 177                     if ch == '\n':
 178                         raise QAPISchemaError(self,
 179                                               'Missing terminating "\'"')
 180                     if esc:
 181                         if ch == 'b':
 182                             string += '\b'
 183                         elif ch == 'f':
 184                             string += '\f'
 185                         elif ch == 'n':
 186                             string += '\n'
 187                         elif ch == 'r':
 188                             string += '\r'
 189                         elif ch == 't':
 190                             string += '\t'
 191                         elif ch == 'u':
 192                             value = 0
 193                             for x in range(0, 4):
 194                                 ch = self.src[self.cursor]
 195                                 self.cursor += 1
 196                                 if ch not in "0123456789abcdefABCDEF":
 197                                     raise QAPISchemaError(self,
 198                                                           '\\u escape needs 4 '
 199                                                           'hex digits')
 200                                 value = (value << 4) + int(ch, 16)
 201                             # If Python 2 and 3 didn't disagree so much on
 202                             # how to handle Unicode, then we could allow
 203                             # Unicode string defaults.  But most of QAPI is
 204                             # ASCII-only, so we aren't losing much for now.
 205                             if not value or value > 0x7f:
 206                                 raise QAPISchemaError(self,
 207                                                       'For now, \\u escape '
 208                                                       'only supports non-zero '
 209                                                       'values up to \\u007f')
 210                             string += chr(value)
 211                         elif ch in "\\/'\"":
 212                             string += ch
 213                         else:
 214                             raise QAPISchemaError(self,
 215                                                   "Unknown escape \\%s" %ch)
 216                         esc = False
 217                     elif ch == "\\":
 218                         esc = True
 219                     elif ch == "'":
 220                         self.val = string
 221                         return
 222                     else:
 223                         string += ch
 224             elif self.src.startswith("true", self.pos):
 225                 self.val = True
 226                 self.cursor += 3
 227                 return
 228             elif self.src.startswith("false", self.pos):
 229                 self.val = False
 230                 self.cursor += 4
 231                 return
 232             elif self.src.startswith("null", self.pos):
 233                 self.val = None
 234                 self.cursor += 3
 235                 return
 236             elif self.tok == '\n':
 237                 if self.cursor == len(self.src):
 238                     self.tok = None
 239                     return
 240                 self.line += 1
 241                 self.line_pos = self.cursor
 242             elif not self.tok.isspace():
 243                 raise QAPISchemaError(self, 'Stray "%s"' % self.tok)
 244
 245     def get_members(self):
 246         expr = OrderedDict()
 247         if self.tok == '}':
 248             self.accept()
 249             return expr
 250         if self.tok != "'":
 251             raise QAPISchemaError(self, 'Expected string or "}"')
 252         while True:
 253             key = self.val
 254             self.accept()
 255             if self.tok != ':':
 256                 raise QAPISchemaError(self, 'Expected ":"')
 257             self.accept()
 258             if key in expr:
 259                 raise QAPISchemaError(self, 'Duplicate key "%s"' % key)
 260             expr[key] = self.get_expr(True)
 261             if self.tok == '}':
 262                 self.accept()
 263                 return expr
 264             if self.tok != ',':
 265                 raise QAPISchemaError(self, 'Expected "," or "}"')
 266             self.accept()
 267             if self.tok != "'":
 268                 raise QAPISchemaError(self, 'Expected string')
 269
 270     def get_values(self):
 271         expr = []
 272         if self.tok == ']':
 273             self.accept()
 274             return expr
 275         if not self.tok in "{['tfn":
 276             raise QAPISchemaError(self, 'Expected "{", "[", "]", string, '
 277                                   'boolean or "null"')
 278         while True:
 279             expr.append(self.get_expr(True))
 280             if self.tok == ']':
 281                 self.accept()
 282                 return expr
 283             if self.tok != ',':
 284                 raise QAPISchemaError(self, 'Expected "," or "]"')
 285             self.accept()
 286
 287     def get_expr(self, nested):
 288         if self.tok != '{' and not nested:
 289             raise QAPISchemaError(self, 'Expected "{"')
 290         if self.tok == '{':
 291             self.accept()
 292             expr = self.get_members()
 293         elif self.tok == '[':
 294             self.accept()
 295             expr = self.get_values()
 296         elif self.tok in "'tfn":
 297             expr = self.val
 298             self.accept()
 299         else:
 300             raise QAPISchemaError(self, 'Expected "{", "[" or string')
 301         return expr
 302
 303 #
 304 # Semantic analysis of schema expressions
 305 #
 306
 307 def find_base_fields(base):
 308     base_struct_define = find_struct(base)
 309     if not base_struct_define:
 310         return None
 311     return base_struct_define['data']
 312
 313 # Return the qtype of an alternate branch, or None on error.
 314 def find_alternate_member_qtype(qapi_type):
 315     if builtin_types.has_key(qapi_type):
 316         return builtin_types[qapi_type]
 317     elif find_struct(qapi_type):
 318         return "QTYPE_QDICT"
 319     elif find_enum(qapi_type):
 320         return "QTYPE_QSTRING"
 321     elif find_union(qapi_type):
 322         return "QTYPE_QDICT"
 323     return None
 324
 325 # Return the discriminator enum define if discriminator is specified as an
 326 # enum type, otherwise return None.
 327 def discriminator_find_enum_define(expr):
 328     base = expr.get('base')
 329     discriminator = expr.get('discriminator')
 330
 331     if not (discriminator and base):
 332         return None
 333
 334     base_fields = find_base_fields(base)
 335     if not base_fields:
 336         return None
 337
 338     discriminator_type = base_fields.get(discriminator)
 339     if not discriminator_type:
 340         return None
 341
 342     return find_enum(discriminator_type)
 343
 344 valid_name = re.compile('^[a-zA-Z_][a-zA-Z0-9_.-]*$')
 345 def check_name(expr_info, source, name, allow_optional = False,
 346                enum_member = False):
 347     global valid_name
 348     membername = name
 349
 350     if not isinstance(name, str):
 351         raise QAPIExprError(expr_info,
 352                             "%s requires a string name" % source)
 353     if name.startswith('*'):
 354         membername = name[1:]
 355         if not allow_optional:
 356             raise QAPIExprError(expr_info,
 357                                 "%s does not allow optional name '%s'"
 358                                 % (source, name))
 359     # Enum members can start with a digit, because the generated C
 360     # code always prefixes it with the enum name
 361     if enum_member:
 362         membername = '_' + membername
 363     if not valid_name.match(membername):
 364         raise QAPIExprError(expr_info,
 365                             "%s uses invalid name '%s'" % (source, name))
 366
 367 def add_name(name, info, meta, implicit = False):
 368     global all_names
 369     check_name(info, "'%s'" % meta, name)
 370     if name in all_names:
 371         raise QAPIExprError(info,
 372                             "%s '%s' is already defined"
 373                             % (all_names[name], name))
 374     if not implicit and name[-4:] == 'Kind':
 375         raise QAPIExprError(info,
 376                             "%s '%s' should not end in 'Kind'"
 377                             % (meta, name))
 378     all_names[name] = meta
 379
 380 def add_struct(definition, info):
 381     global struct_types
 382     name = definition['struct']
 383     add_name(name, info, 'struct')
 384     struct_types.append(definition)
 385
 386 def find_struct(name):
 387     global struct_types
 388     for struct in struct_types:
 389         if struct['struct'] == name:
 390             return struct
 391     return None
 392
 393 def add_union(definition, info):
 394     global union_types
 395     name = definition['union']
 396     add_name(name, info, 'union')
 397     union_types.append(definition)
 398
 399 def find_union(name):
 400     global union_types
 401     for union in union_types:
 402         if union['union'] == name:
 403             return union
 404     return None
 405
 406 def add_enum(name, info, enum_values = None, implicit = False):
 407     global enum_types
 408     add_name(name, info, 'enum', implicit)
 409     enum_types.append({"enum_name": name, "enum_values": enum_values})
 410
 411 def find_enum(name):
 412     global enum_types
 413     for enum in enum_types:
 414         if enum['enum_name'] == name:
 415             return enum
 416     return None
 417
 418 def is_enum(name):
 419     return find_enum(name) != None
 420
 421 def check_type(expr_info, source, value, allow_array = False,
 422                allow_dict = False, allow_optional = False,
 423                allow_star = False, allow_metas = []):
 424     global all_names
 425     orig_value = value
 426
 427     if value is None:
 428         return
 429
 430     if allow_star and value == '**':
 431         return
 432
 433     # Check if array type for value is okay
 434     if isinstance(value, list):
 435         if not allow_array:
 436             raise QAPIExprError(expr_info,
 437                                 "%s cannot be an array" % source)
 438         if len(value) != 1 or not isinstance(value[0], str):
 439             raise QAPIExprError(expr_info,
 440                                 "%s: array type must contain single type name"
 441                                 % source)
 442         value = value[0]
 443         orig_value = "array of %s" %value
 444
 445     # Check if type name for value is okay
 446     if isinstance(value, str):
 447         if value == '**':
 448             raise QAPIExprError(expr_info,
 449                                 "%s uses '**' but did not request 'gen':false"
 450                                 % source)
 451         if not value in all_names:
 452             raise QAPIExprError(expr_info,
 453                                 "%s uses unknown type '%s'"
 454                                 % (source, orig_value))
 455         if not all_names[value] in allow_metas:
 456             raise QAPIExprError(expr_info,
 457                                 "%s cannot use %s type '%s'"
 458                                 % (source, all_names[value], orig_value))
 459         return
 460
 461     # value is a dictionary, check that each member is okay
 462     if not isinstance(value, OrderedDict):
 463         raise QAPIExprError(expr_info,
 464                             "%s should be a dictionary" % source)
 465     if not allow_dict:
 466         raise QAPIExprError(expr_info,
 467                             "%s should be a type name" % source)
 468     for (key, arg) in value.items():
 469         check_name(expr_info, "Member of %s" % source, key,
 470                    allow_optional=allow_optional)
 471         # Todo: allow dictionaries to represent default values of
 472         # an optional argument.
 473         check_type(expr_info, "Member '%s' of %s" % (key, source), arg,
 474                    allow_array=True, allow_star=allow_star,
 475                    allow_metas=['built-in', 'union', 'alternate', 'struct',
 476                                 'enum'])
 477
 478 def check_member_clash(expr_info, base_name, data, source = ""):
 479     base = find_struct(base_name)
 480     assert base
 481     base_members = base['data']
 482     for key in data.keys():
 483         if key.startswith('*'):
 484             key = key[1:]
 485         if key in base_members or "*" + key in base_members:
 486             raise QAPIExprError(expr_info,
 487                                 "Member name '%s'%s clashes with base '%s'"
 488                                 % (key, source, base_name))
 489     if base.get('base'):
 490         check_member_clash(expr_info, base['base'], data, source)
 491
 492 def check_command(expr, expr_info):
 493     name = expr['command']
 494     allow_star = expr.has_key('gen')
 495
 496     check_type(expr_info, "'data' for command '%s'" % name,
 497                expr.get('data'), allow_dict=True, allow_optional=True,
 498                allow_metas=['union', 'struct'], allow_star=allow_star)
 499     returns_meta = ['union', 'struct']
 500     if name in returns_whitelist:
 501         returns_meta += ['built-in', 'alternate', 'enum']
 502     check_type(expr_info, "'returns' for command '%s'" % name,
 503                expr.get('returns'), allow_array=True, allow_dict=True,
 504                allow_optional=True, allow_metas=returns_meta,
 505                allow_star=allow_star)
 506
 507 def check_event(expr, expr_info):
 508     global events
 509     name = expr['event']
 510     params = expr.get('data')
 511
 512     if name.upper() == 'MAX':
 513         raise QAPIExprError(expr_info, "Event name 'MAX' cannot be created")
 514     events.append(name)
 515     check_type(expr_info, "'data' for event '%s'" % name,
 516                expr.get('data'), allow_dict=True, allow_optional=True,
 517                allow_metas=['union', 'struct'])
 518
 519 def check_union(expr, expr_info):
 520     name = expr['union']
 521     base = expr.get('base')
 522     discriminator = expr.get('discriminator')
 523     members = expr['data']
 524     values = { 'MAX': '(automatic)' }
 525
 526     # If the object has a member 'base', its value must name a struct,
 527     # and there must be a discriminator.
 528     if base is not None:
 529         if discriminator is None:
 530             raise QAPIExprError(expr_info,
 531                                 "Union '%s' requires a discriminator to go "
 532                                 "along with base" %name)
 533
 534     # Two types of unions, determined by discriminator.
 535
 536     # With no discriminator it is a simple union.
 537     if discriminator is None:
 538         enum_define = None
 539         allow_metas=['built-in', 'union', 'alternate', 'struct', 'enum']
 540         if base is not None:
 541             raise QAPIExprError(expr_info,
 542                                 "Simple union '%s' must not have a base"
 543                                 % name)
 544
 545     # Else, it's a flat union.
 546     else:
 547         # The object must have a string member 'base'.
 548         if not isinstance(base, str):
 549             raise QAPIExprError(expr_info,
 550                                 "Flat union '%s' must have a string base field"
 551                                 % name)
 552         base_fields = find_base_fields(base)
 553         if not base_fields:
 554             raise QAPIExprError(expr_info,
 555                                 "Base '%s' is not a valid struct"
 556                                 % base)
 557
 558         # The value of member 'discriminator' must name a non-optional
 559         # member of the base struct.
 560         check_name(expr_info, "Discriminator of flat union '%s'" % name,
 561                    discriminator)
 562         discriminator_type = base_fields.get(discriminator)
 563         if not discriminator_type:
 564             raise QAPIExprError(expr_info,
 565                                 "Discriminator '%s' is not a member of base "
 566                                 "struct '%s'"
 567                                 % (discriminator, base))
 568         enum_define = find_enum(discriminator_type)
 569         allow_metas=['struct']
 570         # Do not allow string discriminator
 571         if not enum_define:
 572             raise QAPIExprError(expr_info,
 573                                 "Discriminator '%s' must be of enumeration "
 574                                 "type" % discriminator)
 575
 576     # Check every branch
 577     for (key, value) in members.items():
 578         check_name(expr_info, "Member of union '%s'" % name, key)
 579
 580         # Each value must name a known type; furthermore, in flat unions,
 581         # branches must be a struct with no overlapping member names
 582         check_type(expr_info, "Member '%s' of union '%s'" % (key, name),
 583                    value, allow_array=not base, allow_metas=allow_metas)
 584         if base:
 585             branch_struct = find_struct(value)
 586             assert branch_struct
 587             check_member_clash(expr_info, base, branch_struct['data'],
 588                                " of branch '%s'" % key)
 589
 590         # If the discriminator names an enum type, then all members
 591         # of 'data' must also be members of the enum type.
 592         if enum_define:
 593             if not key in enum_define['enum_values']:
 594                 raise QAPIExprError(expr_info,
 595                                     "Discriminator value '%s' is not found in "
 596                                     "enum '%s'" %
 597                                     (key, enum_define["enum_name"]))
 598
 599         # Otherwise, check for conflicts in the generated enum
 600         else:
 601             c_key = camel_to_upper(key)
 602             if c_key in values:
 603                 raise QAPIExprError(expr_info,
 604                                     "Union '%s' member '%s' clashes with '%s'"
 605                                     % (name, key, values[c_key]))
 606             values[c_key] = key
 607
 608 def check_alternate(expr, expr_info):
 609     name = expr['alternate']
 610     members = expr['data']
 611     values = { 'MAX': '(automatic)' }
 612     types_seen = {}
 613
 614     # Check every branch
 615     for (key, value) in members.items():
 616         check_name(expr_info, "Member of alternate '%s'" % name, key)
 617
 618         # Check for conflicts in the generated enum
 619         c_key = camel_to_upper(key)
 620         if c_key in values:
 621             raise QAPIExprError(expr_info,
 622                                 "Alternate '%s' member '%s' clashes with '%s'"
 623                                 % (name, key, values[c_key]))
 624         values[c_key] = key
 625
 626         # Ensure alternates have no type conflicts.
 627         check_type(expr_info, "Member '%s' of alternate '%s'" % (key, name),
 628                    value,
 629                    allow_metas=['built-in', 'union', 'struct', 'enum'])
 630         qtype = find_alternate_member_qtype(value)
 631         assert qtype
 632         if qtype in types_seen:
 633             raise QAPIExprError(expr_info,
 634                                 "Alternate '%s' member '%s' can't "
 635                                 "be distinguished from member '%s'"
 636                                 % (name, key, types_seen[qtype]))
 637         types_seen[qtype] = key
 638
 639 def check_enum(expr, expr_info):
 640     name = expr['enum']
 641     members = expr.get('data')
 642     values = { 'MAX': '(automatic)' }
 643
 644     if not isinstance(members, list):
 645         raise QAPIExprError(expr_info,
 646                             "Enum '%s' requires an array for 'data'" % name)
 647     for member in members:
 648         check_name(expr_info, "Member of enum '%s'" %name, member,
 649                    enum_member=True)
 650         key = camel_to_upper(member)
 651         if key in values:
 652             raise QAPIExprError(expr_info,
 653                                 "Enum '%s' member '%s' clashes with '%s'"
 654                                 % (name, member, values[key]))
 655         values[key] = member
 656
 657 def check_struct(expr, expr_info):
 658     name = expr['struct']
 659     members = expr['data']
 660
 661     check_type(expr_info, "'data' for struct '%s'" % name, members,
 662                allow_dict=True, allow_optional=True)
 663     check_type(expr_info, "'base' for struct '%s'" % name, expr.get('base'),
 664                allow_metas=['struct'])
 665     if expr.get('base'):
 666         check_member_clash(expr_info, expr['base'], expr['data'])
 667
 668 def check_keys(expr_elem, meta, required, optional=[]):
 669     expr = expr_elem['expr']
 670     info = expr_elem['info']
 671     name = expr[meta]
 672     if not isinstance(name, str):
 673         raise QAPIExprError(info,
 674                             "'%s' key must have a string value" % meta)
 675     required = required + [ meta ]
 676     for (key, value) in expr.items():
 677         if not key in required and not key in optional:
 678             raise QAPIExprError(info,
 679                                 "Unknown key '%s' in %s '%s'"
 680                                 % (key, meta, name))
 681         if (key == 'gen' or key == 'success-response') and value != False:
 682             raise QAPIExprError(info,
 683                                 "'%s' of %s '%s' should only use false value"
 684                                 % (key, meta, name))
 685     for key in required:
 686         if not expr.has_key(key):
 687             raise QAPIExprError(info,
 688                                 "Key '%s' is missing from %s '%s'"
 689                                 % (key, meta, name))
 690
 691 def check_exprs(exprs):
 692     global all_names
 693
 694     # Learn the types and check for valid expression keys
 695     for builtin in builtin_types.keys():
 696         all_names[builtin] = 'built-in'
 697     for expr_elem in exprs:
 698         expr = expr_elem['expr']
 699         info = expr_elem['info']
 700         if expr.has_key('enum'):
 701             check_keys(expr_elem, 'enum', ['data'])
 702             add_enum(expr['enum'], info, expr['data'])
 703         elif expr.has_key('union'):
 704             check_keys(expr_elem, 'union', ['data'],
 705                        ['base', 'discriminator'])
 706             add_union(expr, info)
 707         elif expr.has_key('alternate'):
 708             check_keys(expr_elem, 'alternate', ['data'])
 709             add_name(expr['alternate'], info, 'alternate')
 710         elif expr.has_key('struct'):
 711             check_keys(expr_elem, 'struct', ['data'], ['base'])
 712             add_struct(expr, info)
 713         elif expr.has_key('command'):
 714             check_keys(expr_elem, 'command', [],
 715                        ['data', 'returns', 'gen', 'success-response'])
 716             add_name(expr['command'], info, 'command')
 717         elif expr.has_key('event'):
 718             check_keys(expr_elem, 'event', [], ['data'])
 719             add_name(expr['event'], info, 'event')
 720         else:
 721             raise QAPIExprError(expr_elem['info'],
 722                                 "Expression is missing metatype")
 723
 724     # Try again for hidden UnionKind enum
 725     for expr_elem in exprs:
 726         expr = expr_elem['expr']
 727         if expr.has_key('union'):
 728             if not discriminator_find_enum_define(expr):
 729                 add_enum('%sKind' % expr['union'], expr_elem['info'],
 730                          implicit=True)
 731         elif expr.has_key('alternate'):
 732             add_enum('%sKind' % expr['alternate'], expr_elem['info'],
 733                      implicit=True)
 734
 735     # Validate that exprs make sense
 736     for expr_elem in exprs:
 737         expr = expr_elem['expr']
 738         info = expr_elem['info']
 739
 740         if expr.has_key('enum'):
 741             check_enum(expr, info)
 742         elif expr.has_key('union'):
 743             check_union(expr, info)
 744         elif expr.has_key('alternate'):
 745             check_alternate(expr, info)
 746         elif expr.has_key('struct'):
 747             check_struct(expr, info)
 748         elif expr.has_key('command'):
 749             check_command(expr, info)
 750         elif expr.has_key('event'):
 751             check_event(expr, info)
 752         else:
 753             assert False, 'unexpected meta type'
 754
 755     return map(lambda expr_elem: expr_elem['expr'], exprs)
 756
 757 def parse_schema(fname):
 758     try:
 759         schema = QAPISchema(open(fname, "r"))
 760         return check_exprs(schema.exprs)
 761     except (QAPISchemaError, QAPIExprError), e:
 762         print >>sys.stderr, e
 763         exit(1)
 764
 765 #
 766 # Code generation helpers
 767 #
 768
 769 def parse_args(typeinfo):
 770     if isinstance(typeinfo, str):
 771         struct = find_struct(typeinfo)
 772         assert struct != None
 773         typeinfo = struct['data']
 774
 775     for member in typeinfo:
 776         argname = member
 777         argentry = typeinfo[member]
 778         optional = False
 779         if member.startswith('*'):
 780             argname = member[1:]
 781             optional = True
 782         # Todo: allow argentry to be OrderedDict, for providing the
 783         # value of an optional argument.
 784         yield (argname, argentry, optional)
 785
 786 def camel_case(name):
 787     new_name = ''
 788     first = True
 789     for ch in name:
 790         if ch in ['_', '-']:
 791             first = True
 792         elif first:
 793             new_name += ch.upper()
 794             first = False
 795         else:
 796             new_name += ch.lower()
 797     return new_name
 798
 799 # ENUMName -> ENUM_NAME, EnumName1 -> ENUM_NAME1
 800 # ENUM_NAME -> ENUM_NAME, ENUM_NAME1 -> ENUM_NAME1, ENUM_Name2 -> ENUM_NAME2
 801 # ENUM24_Name -> ENUM24_NAME
 802 def camel_to_upper(value):
 803     c_fun_str = c_name(value, False)
 804     if value.isupper():
 805         return c_fun_str
 806
 807     new_name = ''
 808     l = len(c_fun_str)
 809     for i in range(l):
 810         c = c_fun_str[i]
 811         # When c is upper and no "_" appears before, do more checks
 812         if c.isupper() and (i > 0) and c_fun_str[i - 1] != "_":
 813             # Case 1: next string is lower
 814             # Case 2: previous string is digit
 815             if (i < (l - 1) and c_fun_str[i + 1].islower()) or \
 816             c_fun_str[i - 1].isdigit():
 817                 new_name += '_'
 818         new_name += c
 819     return new_name.lstrip('_').upper()
 820
 821 def c_enum_const(type_name, const_name):
 822     return camel_to_upper(type_name + '_' + const_name)
 823
 824 c_name_trans = string.maketrans('.-', '__')
 825
 826 # Map @name to a valid C identifier.
 827 # If @protect, avoid returning certain ticklish identifiers (like
 828 # C keywords) by prepending "q_".
 829 #
 830 # Used for converting 'name' from a 'name':'type' qapi definition
 831 # into a generated struct member, as well as converting type names
 832 # into substrings of a generated C function name.
 833 # '__a.b_c' -> '__a_b_c', 'x-foo' -> 'x_foo'
 834 # protect=True: 'int' -> 'q_int'; protect=False: 'int' -> 'int'
 835 def c_name(name, protect=True):
 836     # ANSI X3J11/88-090, 3.1.1
 837     c89_words = set(['auto', 'break', 'case', 'char', 'const', 'continue',
 838                      'default', 'do', 'double', 'else', 'enum', 'extern', 'float',
 839                      'for', 'goto', 'if', 'int', 'long', 'register', 'return',
 840                      'short', 'signed', 'sizeof', 'static', 'struct', 'switch',
 841                      'typedef', 'union', 'unsigned', 'void', 'volatile', 'while'])
 842     # ISO/IEC 9899:1999, 6.4.1
 843     c99_words = set(['inline', 'restrict', '_Bool', '_Complex', '_Imaginary'])
 844     # ISO/IEC 9899:2011, 6.4.1
 845     c11_words = set(['_Alignas', '_Alignof', '_Atomic', '_Generic', '_Noreturn',
 846                      '_Static_assert', '_Thread_local'])
 847     # GCC http://gcc.gnu.org/onlinedocs/gcc-4.7.1/gcc/C-Extensions.html
 848     # excluding _.*
 849     gcc_words = set(['asm', 'typeof'])
 850     # C++ ISO/IEC 14882:2003 2.11
 851     cpp_words = set(['bool', 'catch', 'class', 'const_cast', 'delete',
 852                      'dynamic_cast', 'explicit', 'false', 'friend', 'mutable',
 853                      'namespace', 'new', 'operator', 'private', 'protected',
 854                      'public', 'reinterpret_cast', 'static_cast', 'template',
 855                      'this', 'throw', 'true', 'try', 'typeid', 'typename',
 856                      'using', 'virtual', 'wchar_t',
 857                      # alternative representations
 858                      'and', 'and_eq', 'bitand', 'bitor', 'compl', 'not',
 859                      'not_eq', 'or', 'or_eq', 'xor', 'xor_eq'])
 860     # namespace pollution:
 861     polluted_words = set(['unix', 'errno'])
 862     if protect and (name in c89_words | c99_words | c11_words | gcc_words | cpp_words | polluted_words):
 863         return "q_" + name
 864     return name.translate(c_name_trans)
 865
 866 # Map type @name to the C typedef name for the list form.
 867 #
 868 # ['Name'] -> 'NameList', ['x-Foo'] -> 'x_FooList', ['int'] -> 'intList'
 869 def c_list_type(name):
 870     return type_name(name) + 'List'
 871
 872 # Map type @value to the C typedef form.
 873 #
 874 # Used for converting 'type' from a 'member':'type' qapi definition
 875 # into the alphanumeric portion of the type for a generated C parameter,
 876 # as well as generated C function names.  See c_type() for the rest of
 877 # the conversion such as adding '*' on pointer types.
 878 # 'int' -> 'int', '[x-Foo]' -> 'x_FooList', '__a.b_c' -> '__a_b_c'
 879 def type_name(value):
 880     if type(value) == list:
 881         return c_list_type(value[0])
 882     if value in builtin_types.keys():
 883         return value
 884     return c_name(value)
 885
 886 eatspace = '\033EATSPACE.'
 887 pointer_suffix = ' *' + eatspace
 888
 889 # Map type @name to its C type expression.
 890 # If @is_param, const-qualify the string type.
 891 #
 892 # This function is used for computing the full C type of 'member':'name'.
 893 # A special suffix is added in c_type() for pointer types, and it's
 894 # stripped in mcgen(). So please notice this when you check the return
 895 # value of c_type() outside mcgen().
 896 def c_type(value, is_param=False):
 897     if value == 'str':
 898         if is_param:
 899             return 'const char' + pointer_suffix
 900         return 'char' + pointer_suffix
 901
 902     elif value == 'int':
 903         return 'int64_t'
 904     elif (value == 'int8' or value == 'int16' or value == 'int32' or
 905           value == 'int64' or value == 'uint8' or value == 'uint16' or
 906           value == 'uint32' or value == 'uint64'):
 907         return value + '_t'
 908     elif value == 'size':
 909         return 'uint64_t'
 910     elif value == 'bool':
 911         return 'bool'
 912     elif value == 'number':
 913         return 'double'
 914     elif type(value) == list:
 915         return c_list_type(value[0]) + pointer_suffix
 916     elif is_enum(value):
 917         return c_name(value)
 918     elif value == None:
 919         return 'void'
 920     elif value in events:
 921         return camel_case(value) + 'Event' + pointer_suffix
 922     else:
 923         # complex type name
 924         assert isinstance(value, str) and value != ""
 925         return c_name(value) + pointer_suffix
 926
 927 def is_c_ptr(value):
 928     return c_type(value).endswith(pointer_suffix)
 929
 930 def genindent(count):
 931     ret = ""
 932     for i in range(count):
 933         ret += " "
 934     return ret
 935
 936 indent_level = 0
 937
 938 def push_indent(indent_amount=4):
 939     global indent_level
 940     indent_level += indent_amount
 941
 942 def pop_indent(indent_amount=4):
 943     global indent_level
 944     indent_level -= indent_amount
 945
 946 def cgen(code, **kwds):
 947     indent = genindent(indent_level)
 948     lines = code.split('\n')
 949     lines = map(lambda x: indent + x, lines)
 950     return '\n'.join(lines) % kwds + '\n'
 951
 952 def mcgen(code, **kwds):
 953     raw = cgen('\n'.join(code.split('\n')[1:-1]), **kwds)
 954     return re.sub(re.escape(eatspace) + ' *', '', raw)
 955
 956 def basename(filename):
 957     return filename.split("/")[-1]
 958
 959 def guardname(filename):
 960     guard = basename(filename).rsplit(".", 1)[0]
 961     for substr in [".", " ", "-"]:
 962         guard = guard.replace(substr, "_")
 963     return guard.upper() + '_H'
 964
 965 def guardstart(name):
 966     return mcgen('''
 967
 968 #ifndef %(name)s
 969 #define %(name)s
 970
 971 ''',
 972                  name=guardname(name))
 973
 974 def guardend(name):
 975     return mcgen('''
 976
 977 #endif /* %(name)s */
 978
 979 ''',
 980                  name=guardname(name))
 981
 982 #
 983 # Common command line parsing
 984 #
 985
 986 def parse_command_line(extra_options = "", extra_long_options = []):
 987
 988     try:
 989         opts, args = getopt.gnu_getopt(sys.argv[1:],
 990                                        "chp:o:" + extra_options,
 991                                        ["source", "header", "prefix=",
 992                                         "output-dir="] + extra_long_options)
 993     except getopt.GetoptError, err:
 994         print >>sys.stderr, "%s: %s" % (sys.argv[0], str(err))
 995         sys.exit(1)
 996
 997     output_dir = ""
 998     prefix = ""
 999     do_c = False
1000     do_h = False
1001     extra_opts = []
1002
1003     for oa in opts:
1004         o, a = oa
1005         if o in ("-p", "--prefix"):
1006             prefix = a
1007         elif o in ("-o", "--output-dir"):
1008             output_dir = a + "/"
1009         elif o in ("-c", "--source"):
1010             do_c = True
1011         elif o in ("-h", "--header"):
1012             do_h = True
1013         else:
1014             extra_opts.append(oa)
1015
1016     if not do_c and not do_h:
1017         do_c = True
1018         do_h = True
1019
1020     if len(args) != 1:
1021         print >>sys.stderr, "%s: need exactly one argument" % sys.argv[0]
1022         sys.exit(1)
1023     fname = args[0]
1024
1025     return (fname, output_dir, do_c, do_h, prefix, extra_opts)
1026
1027 #
1028 # Generate output files with boilerplate
1029 #
1030
1031 def open_output(output_dir, do_c, do_h, prefix, c_file, h_file,
1032                 c_comment, h_comment):
1033     c_file = output_dir + prefix + c_file
1034     h_file = output_dir + prefix + h_file
1035
1036     try:
1037         os.makedirs(output_dir)
1038     except os.error, e:
1039         if e.errno != errno.EEXIST:
1040             raise
1041
1042     def maybe_open(really, name, opt):
1043         if really:
1044             return open(name, opt)
1045         else:
1046             import StringIO
1047             return StringIO.StringIO()
1048
1049     fdef = maybe_open(do_c, c_file, 'w')
1050     fdecl = maybe_open(do_h, h_file, 'w')
1051
1052     fdef.write(mcgen('''
1053 /* AUTOMATICALLY GENERATED, DO NOT MODIFY */
1054 %(comment)s
1055 ''',
1056                      comment = c_comment))
1057
1058     fdecl.write(mcgen('''
1059 /* AUTOMATICALLY GENERATED, DO NOT MODIFY */
1060 %(comment)s
1061 #ifndef %(guard)s
1062 #define %(guard)s
1063
1064 ''',
1065                       comment = h_comment, guard = guardname(h_file)))
1066
1067     return (fdef, fdecl)
1068
1069 def close_output(fdef, fdecl):
1070     fdecl.write('''
1071 #endif
1072 ''')
1073     fdecl.close()
1074     fdef.close()