scripts/qapi/gen.py

   1 # -*- coding: utf-8 -*-
   2 #
   3 # QAPI code generation
   4 #
   5 # Copyright (c) 2018-2019 Red Hat Inc.
   6 #
   7 # Authors:
   8 #  Markus Armbruster <[email protected]>
   9 #  Marc-André Lureau <[email protected]>
  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
  15 import errno
  16 import os
  17 import re
  18 from contextlib import contextmanager
  19
  20 from qapi.common import *
  21 from qapi.schema import QAPISchemaVisitor
  22
  23
  24 class QAPIGen:
  25
  26     def __init__(self, fname):
  27         self.fname = fname
  28         self._preamble = ''
  29         self._body = ''
  30
  31     def preamble_add(self, text):
  32         self._preamble += text
  33
  34     def add(self, text):
  35         self._body += text
  36
  37     def get_content(self):
  38         return self._top() + self._preamble + self._body + self._bottom()
  39
  40     def _top(self):
  41         return ''
  42
  43     def _bottom(self):
  44         return ''
  45
  46     def write(self, output_dir):
  47         # Include paths starting with ../ are used to reuse modules of the main
  48         # schema in specialised schemas. Don't overwrite the files that are
  49         # already generated for the main schema.
  50         if self.fname.startswith('../'):
  51             return
  52         pathname = os.path.join(output_dir, self.fname)
  53         odir = os.path.dirname(pathname)
  54         if odir:
  55             try:
  56                 os.makedirs(odir)
  57             except os.error as e:
  58                 if e.errno != errno.EEXIST:
  59                     raise
  60         fd = os.open(pathname, os.O_RDWR | os.O_CREAT, 0o666)
  61         f = open(fd, 'r+', encoding='utf-8')
  62         text = self.get_content()
  63         oldtext = f.read(len(text) + 1)
  64         if text != oldtext:
  65             f.seek(0)
  66             f.truncate(0)
  67             f.write(text)
  68         f.close()
  69
  70
  71 def _wrap_ifcond(ifcond, before, after):
  72     if before == after:
  73         return after   # suppress empty #if ... #endif
  74
  75     assert after.startswith(before)
  76     out = before
  77     added = after[len(before):]
  78     if added[0] == '\n':
  79         out += '\n'
  80         added = added[1:]
  81     out += gen_if(ifcond)
  82     out += added
  83     out += gen_endif(ifcond)
  84     return out
  85
  86
  87 class QAPIGenCCode(QAPIGen):
  88
  89     def __init__(self, fname):
  90         super().__init__(fname)
  91         self._start_if = None
  92
  93     def start_if(self, ifcond):
  94         assert self._start_if is None
  95         self._start_if = (ifcond, self._body, self._preamble)
  96
  97     def end_if(self):
  98         assert self._start_if
  99         self._wrap_ifcond()
 100         self._start_if = None
 101
 102     def _wrap_ifcond(self):
 103         self._body = _wrap_ifcond(self._start_if[0],
 104                                   self._start_if[1], self._body)
 105         self._preamble = _wrap_ifcond(self._start_if[0],
 106                                       self._start_if[2], self._preamble)
 107
 108     def get_content(self):
 109         assert self._start_if is None
 110         return super().get_content()
 111
 112
 113 class QAPIGenC(QAPIGenCCode):
 114
 115     def __init__(self, fname, blurb, pydoc):
 116         super().__init__(fname)
 117         self._blurb = blurb
 118         self._copyright = '\n * '.join(re.findall(r'^Copyright .*', pydoc,
 119                                                   re.MULTILINE))
 120
 121     def _top(self):
 122         return mcgen('''
 123 /* AUTOMATICALLY GENERATED, DO NOT MODIFY */
 124
 125 /*
 126 %(blurb)s
 127  *
 128  * %(copyright)s
 129  *
 130  * This work is licensed under the terms of the GNU LGPL, version 2.1 or later.
 131  * See the COPYING.LIB file in the top-level directory.
 132  */
 133
 134 ''',
 135                      blurb=self._blurb, copyright=self._copyright)
 136
 137     def _bottom(self):
 138         return mcgen('''
 139
 140 /* Dummy declaration to prevent empty .o file */
 141 char qapi_dummy_%(name)s;
 142 ''',
 143                      name=c_fname(self.fname))
 144
 145
 146 class QAPIGenH(QAPIGenC):
 147
 148     def _top(self):
 149         return super()._top() + guardstart(self.fname)
 150
 151     def _bottom(self):
 152         return guardend(self.fname)
 153
 154
 155 @contextmanager
 156 def ifcontext(ifcond, *args):
 157     """
 158     A with-statement context manager that wraps with `start_if()` / `end_if()`.
 159
 160     :param ifcond: A list of conditionals, passed to `start_if()`.
 161     :param args: any number of `QAPIGenCCode`.
 162
 163     Example::
 164
 165         with ifcontext(ifcond, self._genh, self._genc):
 166             modify self._genh and self._genc ...
 167
 168     Is equivalent to calling::
 169
 170         self._genh.start_if(ifcond)
 171         self._genc.start_if(ifcond)
 172         modify self._genh and self._genc ...
 173         self._genh.end_if()
 174         self._genc.end_if()
 175     """
 176     for arg in args:
 177         arg.start_if(ifcond)
 178     yield
 179     for arg in args:
 180         arg.end_if()
 181
 182
 183 class QAPISchemaMonolithicCVisitor(QAPISchemaVisitor):
 184
 185     def __init__(self, prefix, what, blurb, pydoc):
 186         self._prefix = prefix
 187         self._what = what
 188         self._genc = QAPIGenC(self._prefix + self._what + '.c',
 189                               blurb, pydoc)
 190         self._genh = QAPIGenH(self._prefix + self._what + '.h',
 191                               blurb, pydoc)
 192
 193     def write(self, output_dir):
 194         self._genc.write(output_dir)
 195         self._genh.write(output_dir)
 196
 197
 198 class QAPISchemaModularCVisitor(QAPISchemaVisitor):
 199
 200     def __init__(self, prefix, what, user_blurb, builtin_blurb, pydoc):
 201         self._prefix = prefix
 202         self._what = what
 203         self._user_blurb = user_blurb
 204         self._builtin_blurb = builtin_blurb
 205         self._pydoc = pydoc
 206         self._genc = None
 207         self._genh = None
 208         self._module = {}
 209         self._main_module = None
 210
 211     @staticmethod
 212     def _is_user_module(name):
 213         return name and not name.startswith('./')
 214
 215     @staticmethod
 216     def _is_builtin_module(name):
 217         return not name
 218
 219     def _module_dirname(self, what, name):
 220         if self._is_user_module(name):
 221             return os.path.dirname(name)
 222         return ''
 223
 224     def _module_basename(self, what, name):
 225         ret = '' if self._is_builtin_module(name) else self._prefix
 226         if self._is_user_module(name):
 227             basename = os.path.basename(name)
 228             ret += what
 229             if name != self._main_module:
 230                 ret += '-' + os.path.splitext(basename)[0]
 231         else:
 232             name = name[2:] if name else 'builtin'
 233             ret += re.sub(r'-', '-' + name + '-', what)
 234         return ret
 235
 236     def _module_filename(self, what, name):
 237         return os.path.join(self._module_dirname(what, name),
 238                             self._module_basename(what, name))
 239
 240     def _add_module(self, name, blurb):
 241         basename = self._module_filename(self._what, name)
 242         genc = QAPIGenC(basename + '.c', blurb, self._pydoc)
 243         genh = QAPIGenH(basename + '.h', blurb, self._pydoc)
 244         self._module[name] = (genc, genh)
 245         self._genc, self._genh = self._module[name]
 246
 247     def _add_user_module(self, name, blurb):
 248         assert self._is_user_module(name)
 249         if self._main_module is None:
 250             self._main_module = name
 251         self._add_module(name, blurb)
 252
 253     def _add_system_module(self, name, blurb):
 254         self._add_module(name and './' + name, blurb)
 255
 256     def write(self, output_dir, opt_builtins=False):
 257         for name in self._module:
 258             if self._is_builtin_module(name) and not opt_builtins:
 259                 continue
 260             (genc, genh) = self._module[name]
 261             genc.write(output_dir)
 262             genh.write(output_dir)
 263
 264     def _begin_system_module(self, name):
 265         pass
 266
 267     def _begin_user_module(self, name):
 268         pass
 269
 270     def visit_module(self, name):
 271         if name is None:
 272             if self._builtin_blurb:
 273                 self._add_system_module(None, self._builtin_blurb)
 274                 self._begin_system_module(name)
 275             else:
 276                 # The built-in module has not been created.  No code may
 277                 # be generated.
 278                 self._genc = None
 279                 self._genh = None
 280         else:
 281             self._add_user_module(name, self._user_blurb)
 282             self._begin_user_module(name)
 283
 284     def visit_include(self, name, info):
 285         relname = os.path.relpath(self._module_filename(self._what, name),
 286                                   os.path.dirname(self._genh.fname))
 287         self._genh.preamble_add(mcgen('''
 288 #include "%(relname)s.h"
 289 ''',
 290                                       relname=relname))