scripts/qapi/gen.py

   1 # -*- coding: utf-8 -*-
   2 #
   3 # QAPI code generation
   4 #
   5 # Copyright (c) 2015-2019 Red Hat Inc.
   6 #
   7 # Authors:
   8 #  Markus Armbruster <armbru@redhat.com>
   9 #  Marc-André Lureau <marcandre.lureau@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 from contextlib import contextmanager
  15 import os
  16 import re
  17 from typing import (
  18     Dict,
  19     Iterator,
  20     Optional,
  21     Sequence,
  22     Tuple,
  23 )
  24
  25 from .common import (
  26     c_fname,
  27     c_name,
  28     guardend,
  29     guardstart,
  30     mcgen,
  31 )
  32 from .schema import (
  33     QAPISchemaFeature,
  34     QAPISchemaIfCond,
  35     QAPISchemaModule,
  36     QAPISchemaObjectType,
  37     QAPISchemaVisitor,
  38 )
  39 from .source import QAPISourceInfo
  40
  41
  42 def gen_special_features(features: Sequence[QAPISchemaFeature]) -> str:
  43     special_features = [f"1u << QAPI_{feat.name.upper()}"
  44                         for feat in features if feat.is_special()]
  45     return ' | '.join(special_features) or '0'
  46
  47
  48 class QAPIGen:
  49     def __init__(self, fname: str):
  50         self.fname = fname
  51         self._preamble = ''
  52         self._body = ''
  53
  54     def preamble_add(self, text: str) -> None:
  55         self._preamble += text
  56
  57     def add(self, text: str) -> None:
  58         self._body += text
  59
  60     def get_content(self) -> str:
  61         return self._top() + self._preamble + self._body + self._bottom()
  62
  63     def _top(self) -> str:
  64         # pylint: disable=no-self-use
  65         return ''
  66
  67     def _bottom(self) -> str:
  68         # pylint: disable=no-self-use
  69         return ''
  70
  71     def write(self, output_dir: str) -> None:
  72         # Include paths starting with ../ are used to reuse modules of the main
  73         # schema in specialised schemas. Don't overwrite the files that are
  74         # already generated for the main schema.
  75         if self.fname.startswith('../'):
  76             return
  77         pathname = os.path.join(output_dir, self.fname)
  78         odir = os.path.dirname(pathname)
  79
  80         if odir:
  81             os.makedirs(odir, exist_ok=True)
  82
  83         # use os.open for O_CREAT to create and read a non-existant file
  84         fd = os.open(pathname, os.O_RDWR | os.O_CREAT, 0o666)
  85         with os.fdopen(fd, 'r+', encoding='utf-8') as fp:
  86             text = self.get_content()
  87             oldtext = fp.read(len(text) + 1)
  88             if text != oldtext:
  89                 fp.seek(0)
  90                 fp.truncate(0)
  91                 fp.write(text)
  92
  93
  94 def _wrap_ifcond(ifcond: QAPISchemaIfCond, before: str, after: str) -> str:
  95     if before == after:
  96         return after   # suppress empty #if ... #endif
  97
  98     assert after.startswith(before)
  99     out = before
 100     added = after[len(before):]
 101     if added[0] == '\n':
 102         out += '\n'
 103         added = added[1:]
 104     out += ifcond.gen_if()
 105     out += added
 106     out += ifcond.gen_endif()
 107     return out
 108
 109
 110 def build_params(arg_type: Optional[QAPISchemaObjectType],
 111                  boxed: bool,
 112                  extra: Optional[str] = None) -> str:
 113     ret = ''
 114     sep = ''
 115     if boxed:
 116         assert arg_type
 117         ret += '%s arg' % arg_type.c_param_type()
 118         sep = ', '
 119     elif arg_type:
 120         assert not arg_type.variants
 121         for memb in arg_type.members:
 122             ret += sep
 123             sep = ', '
 124             if memb.optional:
 125                 ret += 'bool has_%s, ' % c_name(memb.name)
 126             ret += '%s %s' % (memb.type.c_param_type(),
 127                               c_name(memb.name))
 128     if extra:
 129         ret += sep + extra
 130     return ret if ret else 'void'
 131
 132
 133 class QAPIGenCCode(QAPIGen):
 134     def __init__(self, fname: str):
 135         super().__init__(fname)
 136         self._start_if: Optional[Tuple[QAPISchemaIfCond, str, str]] = None
 137
 138     def start_if(self, ifcond: QAPISchemaIfCond) -> None:
 139         assert self._start_if is None
 140         self._start_if = (ifcond, self._body, self._preamble)
 141
 142     def end_if(self) -> None:
 143         assert self._start_if is not None
 144         self._body = _wrap_ifcond(self._start_if[0],
 145                                   self._start_if[1], self._body)
 146         self._preamble = _wrap_ifcond(self._start_if[0],
 147                                       self._start_if[2], self._preamble)
 148         self._start_if = None
 149
 150     def get_content(self) -> str:
 151         assert self._start_if is None
 152         return super().get_content()
 153
 154
 155 class QAPIGenC(QAPIGenCCode):
 156     def __init__(self, fname: str, blurb: str, pydoc: str):
 157         super().__init__(fname)
 158         self._blurb = blurb
 159         self._copyright = '\n * '.join(re.findall(r'^Copyright .*', pydoc,
 160                                                   re.MULTILINE))
 161
 162     def _top(self) -> str:
 163         return mcgen('''
 164 /* AUTOMATICALLY GENERATED, DO NOT MODIFY */
 165
 166 /*
 167 %(blurb)s
 168  *
 169  * %(copyright)s
 170  *
 171  * This work is licensed under the terms of the GNU LGPL, version 2.1 or later.
 172  * See the COPYING.LIB file in the top-level directory.
 173  */
 174
 175 ''',
 176                      blurb=self._blurb, copyright=self._copyright)
 177
 178     def _bottom(self) -> str:
 179         return mcgen('''
 180
 181 /* Dummy declaration to prevent empty .o file */
 182 char qapi_dummy_%(name)s;
 183 ''',
 184                      name=c_fname(self.fname))
 185
 186
 187 class QAPIGenH(QAPIGenC):
 188     def _top(self) -> str:
 189         return super()._top() + guardstart(self.fname)
 190
 191     def _bottom(self) -> str:
 192         return guardend(self.fname)
 193
 194
 195 class QAPIGenTrace(QAPIGen):
 196     def _top(self) -> str:
 197         return super()._top() + '# AUTOMATICALLY GENERATED, DO NOT MODIFY\n\n'
 198
 199
 200 @contextmanager
 201 def ifcontext(ifcond: QAPISchemaIfCond, *args: QAPIGenCCode) -> Iterator[None]:
 202     """
 203     A with-statement context manager that wraps with `start_if()` / `end_if()`.
 204
 205     :param ifcond: A sequence of conditionals, passed to `start_if()`.
 206     :param args: any number of `QAPIGenCCode`.
 207
 208     Example::
 209
 210         with ifcontext(ifcond, self._genh, self._genc):
 211             modify self._genh and self._genc ...
 212
 213     Is equivalent to calling::
 214
 215         self._genh.start_if(ifcond)
 216         self._genc.start_if(ifcond)
 217         modify self._genh and self._genc ...
 218         self._genh.end_if()
 219         self._genc.end_if()
 220     """
 221     for arg in args:
 222         arg.start_if(ifcond)
 223     yield
 224     for arg in args:
 225         arg.end_if()
 226
 227
 228 class QAPISchemaMonolithicCVisitor(QAPISchemaVisitor):
 229     def __init__(self,
 230                  prefix: str,
 231                  what: str,
 232                  blurb: str,
 233                  pydoc: str):
 234         self._prefix = prefix
 235         self._what = what
 236         self._genc = QAPIGenC(self._prefix + self._what + '.c',
 237                               blurb, pydoc)
 238         self._genh = QAPIGenH(self._prefix + self._what + '.h',
 239                               blurb, pydoc)
 240
 241     def write(self, output_dir: str) -> None:
 242         self._genc.write(output_dir)
 243         self._genh.write(output_dir)
 244
 245
 246 class QAPISchemaModularCVisitor(QAPISchemaVisitor):
 247     def __init__(self,
 248                  prefix: str,
 249                  what: str,
 250                  user_blurb: str,
 251                  builtin_blurb: Optional[str],
 252                  pydoc: str,
 253                  gen_tracing: bool = False):
 254         self._prefix = prefix
 255         self._what = what
 256         self._user_blurb = user_blurb
 257         self._builtin_blurb = builtin_blurb
 258         self._pydoc = pydoc
 259         self._current_module: Optional[str] = None
 260         self._module: Dict[str, Tuple[QAPIGenC, QAPIGenH,
 261                                       Optional[QAPIGenTrace]]] = {}
 262         self._main_module: Optional[str] = None
 263         self._gen_tracing = gen_tracing
 264
 265     @property
 266     def _genc(self) -> QAPIGenC:
 267         assert self._current_module is not None
 268         return self._module[self._current_module][0]
 269
 270     @property
 271     def _genh(self) -> QAPIGenH:
 272         assert self._current_module is not None
 273         return self._module[self._current_module][1]
 274
 275     @property
 276     def _gen_trace_events(self) -> QAPIGenTrace:
 277         assert self._gen_tracing
 278         assert self._current_module is not None
 279         gent = self._module[self._current_module][2]
 280         assert gent is not None
 281         return gent
 282
 283     @staticmethod
 284     def _module_dirname(name: str) -> str:
 285         if QAPISchemaModule.is_user_module(name):
 286             return os.path.dirname(name)
 287         return ''
 288
 289     def _module_basename(self, what: str, name: str) -> str:
 290         ret = '' if QAPISchemaModule.is_builtin_module(name) else self._prefix
 291         if QAPISchemaModule.is_user_module(name):
 292             basename = os.path.basename(name)
 293             ret += what
 294             if name != self._main_module:
 295                 ret += '-' + os.path.splitext(basename)[0]
 296         else:
 297             assert QAPISchemaModule.is_system_module(name)
 298             ret += re.sub(r'-', '-' + name[2:] + '-', what)
 299         return ret
 300
 301     def _module_filename(self, what: str, name: str) -> str:
 302         return os.path.join(self._module_dirname(name),
 303                             self._module_basename(what, name))
 304
 305     def _add_module(self, name: str, blurb: str) -> None:
 306         if QAPISchemaModule.is_user_module(name):
 307             if self._main_module is None:
 308                 self._main_module = name
 309         basename = self._module_filename(self._what, name)
 310         genc = QAPIGenC(basename + '.c', blurb, self._pydoc)
 311         genh = QAPIGenH(basename + '.h', blurb, self._pydoc)
 312
 313         gent: Optional[QAPIGenTrace] = None
 314         if self._gen_tracing:
 315             gent = QAPIGenTrace(basename + '.trace-events')
 316
 317         self._module[name] = (genc, genh, gent)
 318         self._current_module = name
 319
 320     @contextmanager
 321     def _temp_module(self, name: str) -> Iterator[None]:
 322         old_module = self._current_module
 323         self._current_module = name
 324         yield
 325         self._current_module = old_module
 326
 327     def write(self, output_dir: str, opt_builtins: bool = False) -> None:
 328         for name, (genc, genh, gent) in self._module.items():
 329             if QAPISchemaModule.is_builtin_module(name) and not opt_builtins:
 330                 continue
 331             genc.write(output_dir)
 332             genh.write(output_dir)
 333             if gent is not None:
 334                 gent.write(output_dir)
 335
 336     def _begin_builtin_module(self) -> None:
 337         pass
 338
 339     def _begin_user_module(self, name: str) -> None:
 340         pass
 341
 342     def visit_module(self, name: str) -> None:
 343         if QAPISchemaModule.is_builtin_module(name):
 344             if self._builtin_blurb:
 345                 self._add_module(name, self._builtin_blurb)
 346                 self._begin_builtin_module()
 347             else:
 348                 # The built-in module has not been created.  No code may
 349                 # be generated.
 350                 self._current_module = None
 351         else:
 352             assert QAPISchemaModule.is_user_module(name)
 353             self._add_module(name, self._user_blurb)
 354             self._begin_user_module(name)
 355
 356     def visit_include(self, name: str, info: Optional[QAPISourceInfo]) -> None:
 357         relname = os.path.relpath(self._module_filename(self._what, name),
 358                                   os.path.dirname(self._genh.fname))
 359         self._genh.preamble_add(mcgen('''
 360 #include "%(relname)s.h"
 361 ''',
 362                                       relname=relname))