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