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 @contextmanager
 196 def ifcontext(ifcond: QAPISchemaIfCond, *args: QAPIGenCCode) -> Iterator[None]:
 197     """
 198     A with-statement context manager that wraps with `start_if()` / `end_if()`.
 199
 200     :param ifcond: A sequence of conditionals, passed to `start_if()`.
 201     :param args: any number of `QAPIGenCCode`.
 202
 203     Example::
 204
 205         with ifcontext(ifcond, self._genh, self._genc):
 206             modify self._genh and self._genc ...
 207
 208     Is equivalent to calling::
 209
 210         self._genh.start_if(ifcond)
 211         self._genc.start_if(ifcond)
 212         modify self._genh and self._genc ...
 213         self._genh.end_if()
 214         self._genc.end_if()
 215     """
 216     for arg in args:
 217         arg.start_if(ifcond)
 218     yield
 219     for arg in args:
 220         arg.end_if()
 221
 222
 223 class QAPISchemaMonolithicCVisitor(QAPISchemaVisitor):
 224     def __init__(self,
 225                  prefix: str,
 226                  what: str,
 227                  blurb: str,
 228                  pydoc: str):
 229         self._prefix = prefix
 230         self._what = what
 231         self._genc = QAPIGenC(self._prefix + self._what + '.c',
 232                               blurb, pydoc)
 233         self._genh = QAPIGenH(self._prefix + self._what + '.h',
 234                               blurb, pydoc)
 235
 236     def write(self, output_dir: str) -> None:
 237         self._genc.write(output_dir)
 238         self._genh.write(output_dir)
 239
 240
 241 class QAPISchemaModularCVisitor(QAPISchemaVisitor):
 242     def __init__(self,
 243                  prefix: str,
 244                  what: str,
 245                  user_blurb: str,
 246                  builtin_blurb: Optional[str],
 247                  pydoc: str):
 248         self._prefix = prefix
 249         self._what = what
 250         self._user_blurb = user_blurb
 251         self._builtin_blurb = builtin_blurb
 252         self._pydoc = pydoc
 253         self._current_module: Optional[str] = None
 254         self._module: Dict[str, Tuple[QAPIGenC, QAPIGenH]] = {}
 255         self._main_module: Optional[str] = None
 256
 257     @property
 258     def _genc(self) -> QAPIGenC:
 259         assert self._current_module is not None
 260         return self._module[self._current_module][0]
 261
 262     @property
 263     def _genh(self) -> QAPIGenH:
 264         assert self._current_module is not None
 265         return self._module[self._current_module][1]
 266
 267     @staticmethod
 268     def _module_dirname(name: str) -> str:
 269         if QAPISchemaModule.is_user_module(name):
 270             return os.path.dirname(name)
 271         return ''
 272
 273     def _module_basename(self, what: str, name: str) -> str:
 274         ret = '' if QAPISchemaModule.is_builtin_module(name) else self._prefix
 275         if QAPISchemaModule.is_user_module(name):
 276             basename = os.path.basename(name)
 277             ret += what
 278             if name != self._main_module:
 279                 ret += '-' + os.path.splitext(basename)[0]
 280         else:
 281             assert QAPISchemaModule.is_system_module(name)
 282             ret += re.sub(r'-', '-' + name[2:] + '-', what)
 283         return ret
 284
 285     def _module_filename(self, what: str, name: str) -> str:
 286         return os.path.join(self._module_dirname(name),
 287                             self._module_basename(what, name))
 288
 289     def _add_module(self, name: str, blurb: str) -> None:
 290         if QAPISchemaModule.is_user_module(name):
 291             if self._main_module is None:
 292                 self._main_module = name
 293         basename = self._module_filename(self._what, name)
 294         genc = QAPIGenC(basename + '.c', blurb, self._pydoc)
 295         genh = QAPIGenH(basename + '.h', blurb, self._pydoc)
 296         self._module[name] = (genc, genh)
 297         self._current_module = name
 298
 299     @contextmanager
 300     def _temp_module(self, name: str) -> Iterator[None]:
 301         old_module = self._current_module
 302         self._current_module = name
 303         yield
 304         self._current_module = old_module
 305
 306     def write(self, output_dir: str, opt_builtins: bool = False) -> None:
 307         for name, (genc, genh) in self._module.items():
 308             if QAPISchemaModule.is_builtin_module(name) and not opt_builtins:
 309                 continue
 310             genc.write(output_dir)
 311             genh.write(output_dir)
 312
 313     def _begin_builtin_module(self) -> None:
 314         pass
 315
 316     def _begin_user_module(self, name: str) -> None:
 317         pass
 318
 319     def visit_module(self, name: str) -> None:
 320         if QAPISchemaModule.is_builtin_module(name):
 321             if self._builtin_blurb:
 322                 self._add_module(name, self._builtin_blurb)
 323                 self._begin_builtin_module()
 324             else:
 325                 # The built-in module has not been created.  No code may
 326                 # be generated.
 327                 self._current_module = None
 328         else:
 329             assert QAPISchemaModule.is_user_module(name)
 330             self._add_module(name, self._user_blurb)
 331             self._begin_user_module(name)
 332
 333     def visit_include(self, name: str, info: Optional[QAPISourceInfo]) -> None:
 334         relname = os.path.relpath(self._module_filename(self._what, name),
 335                                   os.path.dirname(self._genh.fname))
 336         self._genh.preamble_add(mcgen('''
 337 #include "%(relname)s.h"
 338 ''',
 339                                       relname=relname))