Coverage for /pythoncovmergedfiles/medio/medio/usr/local/lib/python3.9/dist-packages/cffi/cparser.py: 61%

1from . import model 

2from .commontypes import COMMON_TYPES, resolve_common_type 

3from .error import FFIError, CDefError 

4try: 

5 from . import _pycparser as pycparser 

6except ImportError: 

7 import pycparser 

8import weakref, re, sys 

9 

10try: 

11 if sys.version_info < (3,): 

12 import thread as _thread 

13 else: 

14 import _thread 

15 lock = _thread.allocate_lock() 

16except ImportError: 

17 lock = None 

18 

19def _workaround_for_static_import_finders(): 

20 # Issue #392: packaging tools like cx_Freeze can not find these 

21 # because pycparser uses exec dynamic import. This is an obscure 

22 # workaround. This function is never called. 

23 import pycparser.yacctab 

24 import pycparser.lextab 

25 

26CDEF_SOURCE_STRING = "<cdef source string>" 

27_r_comment = re.compile(r"/\*.*?\*/|//([^\n\\]|\\.)*?$", 

28 re.DOTALL | re.MULTILINE) 

29_r_define = re.compile(r"^\s*#\s*define\s+([A-Za-z_][A-Za-z_0-9]*)" 

30 r"\b((?:[^\n\\]|\\.)*?)$", 

31 re.DOTALL | re.MULTILINE) 

32_r_line_directive = re.compile(r"^[ \t]*#[ \t]*(?:line|\d+)\b.*$", re.MULTILINE) 

33_r_partial_enum = re.compile(r"=\s*\.\.\.\s*[,}]|\.\.\.\s*\}") 

34_r_enum_dotdotdot = re.compile(r"__dotdotdot\d+__$") 

35_r_partial_array = re.compile(r"\[\s*\.\.\.\s*\]") 

36_r_words = re.compile(r"\w+|\S") 

37_parser_cache = None 

38_r_int_literal = re.compile(r"-?0?x?[0-9a-f]+[lu]*$", re.IGNORECASE) 

39_r_stdcall1 = re.compile(r"\b(__stdcall|WINAPI)\b") 

40_r_stdcall2 = re.compile(r"[(]\s*(__stdcall|WINAPI)\b") 

41_r_cdecl = re.compile(r"\b__cdecl\b") 

42_r_extern_python = re.compile(r'\bextern\s*"' 

43 r'(Python|Python\s*\+\s*C|C\s*\+\s*Python)"\s*.') 

44_r_star_const_space = re.compile( # matches "* const " 

45 r"[*]\s*((const|volatile|restrict)\b\s*)+") 

46_r_int_dotdotdot = re.compile(r"(\b(int|long|short|signed|unsigned|char)\s*)+" 

47 r"\.\.\.") 

48_r_float_dotdotdot = re.compile(r"\b(double|float)\s*\.\.\.") 

49 

50def _get_parser(): 

51 global _parser_cache 

52 if _parser_cache is None: 

53 _parser_cache = pycparser.CParser() 

54 return _parser_cache 

55 

56def _workaround_for_old_pycparser(csource): 

57 # Workaround for a pycparser issue (fixed between pycparser 2.10 and 

58 # 2.14): "char*const***" gives us a wrong syntax tree, the same as 

59 # for "char***(*const)". This means we can't tell the difference 

60 # afterwards. But "char(*const(***))" gives us the right syntax 

61 # tree. The issue only occurs if there are several stars in 

62 # sequence with no parenthesis inbetween, just possibly qualifiers. 

63 # Attempt to fix it by adding some parentheses in the source: each 

64 # time we see "* const" or "* const *", we add an opening 

65 # parenthesis before each star---the hard part is figuring out where 

66 # to close them. 

67 parts = [] 

68 while True: 

69 match = _r_star_const_space.search(csource) 

70 if not match: 

71 break 

72 #print repr(''.join(parts)+csource), '=>', 

73 parts.append(csource[:match.start()]) 

74 parts.append('('); closing = ')' 

75 parts.append(match.group()) # e.g. "* const " 

76 endpos = match.end() 

77 if csource.startswith('*', endpos): 

78 parts.append('('); closing += ')' 

79 level = 0 

80 i = endpos 

81 while i < len(csource): 

82 c = csource[i] 

83 if c == '(': 

84 level += 1 

85 elif c == ')': 

86 if level == 0: 

87 break 

88 level -= 1 

89 elif c in ',;=': 

90 if level == 0: 

91 break 

92 i += 1 

93 csource = csource[endpos:i] + closing + csource[i:] 

94 #print repr(''.join(parts)+csource) 

95 parts.append(csource) 

96 return ''.join(parts) 

97 

98def _preprocess_extern_python(csource): 

99 # input: `extern "Python" int foo(int);` or 

100 # `extern "Python" { int foo(int); }` 

101 # output: 

102 # void __cffi_extern_python_start; 

103 # int foo(int); 

104 # void __cffi_extern_python_stop; 

105 # 

106 # input: `extern "Python+C" int foo(int);` 

107 # output: 

108 # void __cffi_extern_python_plus_c_start; 

109 # int foo(int); 

110 # void __cffi_extern_python_stop; 

111 parts = [] 

112 while True: 

113 match = _r_extern_python.search(csource) 

114 if not match: 

115 break 

116 endpos = match.end() - 1 

117 #print 

118 #print ''.join(parts)+csource 

119 #print '=>' 

120 parts.append(csource[:match.start()]) 

121 if 'C' in match.group(1): 

122 parts.append('void __cffi_extern_python_plus_c_start; ') 

123 else: 

124 parts.append('void __cffi_extern_python_start; ') 

125 if csource[endpos] == '{': 

126 # grouping variant 

127 closing = csource.find('}', endpos) 

128 if closing < 0: 

129 raise CDefError("'extern \"Python\" {': no '}' found") 

130 if csource.find('{', endpos + 1, closing) >= 0: 

131 raise NotImplementedError("cannot use { } inside a block " 

132 "'extern \"Python\" { ... }'") 

133 parts.append(csource[endpos+1:closing]) 

134 csource = csource[closing+1:] 

135 else: 

136 # non-grouping variant 

137 semicolon = csource.find(';', endpos) 

138 if semicolon < 0: 

139 raise CDefError("'extern \"Python\": no ';' found") 

140 parts.append(csource[endpos:semicolon+1]) 

141 csource = csource[semicolon+1:] 

142 parts.append(' void __cffi_extern_python_stop;') 

143 #print ''.join(parts)+csource 

144 #print 

145 parts.append(csource) 

146 return ''.join(parts) 

147 

148def _warn_for_string_literal(csource): 

149 if '"' not in csource: 

150 return 

151 for line in csource.splitlines(): 

152 if '"' in line and not line.lstrip().startswith('#'): 

153 import warnings 

154 warnings.warn("String literal found in cdef() or type source. " 

155 "String literals are ignored here, but you should " 

156 "remove them anyway because some character sequences " 

157 "confuse pre-parsing.") 

158 break 

159 

160def _warn_for_non_extern_non_static_global_variable(decl): 

161 if not decl.storage: 

162 import warnings 

163 warnings.warn("Global variable '%s' in cdef(): for consistency " 

164 "with C it should have a storage class specifier " 

165 "(usually 'extern')" % (decl.name,)) 

166 

167def _remove_line_directives(csource): 

168 # _r_line_directive matches whole lines, without the final \n, if they 

169 # start with '#line' with some spacing allowed, or '#NUMBER'. This 

170 # function stores them away and replaces them with exactly the string 

171 # '#line@N', where N is the index in the list 'line_directives'. 

172 line_directives = [] 

173 def replace(m): 

174 i = len(line_directives) 

175 line_directives.append(m.group()) 

176 return '#line@%d' % i 

177 csource = _r_line_directive.sub(replace, csource) 

178 return csource, line_directives 

179 

180def _put_back_line_directives(csource, line_directives): 

181 def replace(m): 

182 s = m.group() 

183 if not s.startswith('#line@'): 

184 raise AssertionError("unexpected #line directive " 

185 "(should have been processed and removed") 

186 return line_directives[int(s[6:])] 

187 return _r_line_directive.sub(replace, csource) 

188 

189def _preprocess(csource): 

190 # First, remove the lines of the form '#line N "filename"' because 

191 # the "filename" part could confuse the rest 

192 csource, line_directives = _remove_line_directives(csource) 

193 # Remove comments. NOTE: this only work because the cdef() section 

194 # should not contain any string literals (except in line directives)! 

195 def replace_keeping_newlines(m): 

196 return ' ' + m.group().count('\n') * '\n' 

197 csource = _r_comment.sub(replace_keeping_newlines, csource) 

198 # Remove the "#define FOO x" lines 

199 macros = {} 

200 for match in _r_define.finditer(csource): 

201 macroname, macrovalue = match.groups() 

202 macrovalue = macrovalue.replace('\\\n', '').strip() 

203 macros[macroname] = macrovalue 

204 csource = _r_define.sub('', csource) 

205 # 

206 if pycparser.__version__ < '2.14': 

207 csource = _workaround_for_old_pycparser(csource) 

208 # 

209 # BIG HACK: replace WINAPI or __stdcall with "volatile const". 

210 # It doesn't make sense for the return type of a function to be 

211 # "volatile volatile const", so we abuse it to detect __stdcall... 

212 # Hack number 2 is that "int(volatile *fptr)();" is not valid C 

213 # syntax, so we place the "volatile" before the opening parenthesis. 

214 csource = _r_stdcall2.sub(' volatile volatile const(', csource) 

215 csource = _r_stdcall1.sub(' volatile volatile const ', csource) 

216 csource = _r_cdecl.sub(' ', csource) 

217 # 

218 # Replace `extern "Python"` with start/end markers 

219 csource = _preprocess_extern_python(csource) 

220 # 

221 # Now there should not be any string literal left; warn if we get one 

222 _warn_for_string_literal(csource) 

223 # 

224 # Replace "[...]" with "[__dotdotdotarray__]" 

225 csource = _r_partial_array.sub('[__dotdotdotarray__]', csource) 

226 # 

227 # Replace "...}" with "__dotdotdotNUM__}". This construction should 

228 # occur only at the end of enums; at the end of structs we have "...;}" 

229 # and at the end of vararg functions "...);". Also replace "=...[,}]" 

230 # with ",__dotdotdotNUM__[,}]": this occurs in the enums too, when 

231 # giving an unknown value. 

232 matches = list(_r_partial_enum.finditer(csource)) 

233 for number, match in enumerate(reversed(matches)): 

234 p = match.start() 

235 if csource[p] == '=': 

236 p2 = csource.find('...', p, match.end()) 

237 assert p2 > p 

238 csource = '%s,__dotdotdot%d__ %s' % (csource[:p], number, 

239 csource[p2+3:]) 

240 else: 

241 assert csource[p:p+3] == '...' 

242 csource = '%s __dotdotdot%d__ %s' % (csource[:p], number, 

243 csource[p+3:]) 

244 # Replace "int ..." or "unsigned long int..." with "__dotdotdotint__" 

245 csource = _r_int_dotdotdot.sub(' __dotdotdotint__ ', csource) 

246 # Replace "float ..." or "double..." with "__dotdotdotfloat__" 

247 csource = _r_float_dotdotdot.sub(' __dotdotdotfloat__ ', csource) 

248 # Replace all remaining "..." with the same name, "__dotdotdot__", 

249 # which is declared with a typedef for the purpose of C parsing. 

250 csource = csource.replace('...', ' __dotdotdot__ ') 

251 # Finally, put back the line directives 

252 csource = _put_back_line_directives(csource, line_directives) 

253 return csource, macros 

254 

255def _common_type_names(csource): 

256 # Look in the source for what looks like usages of types from the 

257 # list of common types. A "usage" is approximated here as the 

258 # appearance of the word, minus a "definition" of the type, which 

259 # is the last word in a "typedef" statement. Approximative only 

260 # but should be fine for all the common types. 

261 look_for_words = set(COMMON_TYPES) 

262 look_for_words.add(';') 

263 look_for_words.add(',') 

264 look_for_words.add('(') 

265 look_for_words.add(')') 

266 look_for_words.add('typedef') 

267 words_used = set() 

268 is_typedef = False 

269 paren = 0 

270 previous_word = '' 

271 for word in _r_words.findall(csource): 

272 if word in look_for_words: 

273 if word == ';': 

274 if is_typedef: 

275 words_used.discard(previous_word) 

276 look_for_words.discard(previous_word) 

277 is_typedef = False 

278 elif word == 'typedef': 

279 is_typedef = True 

280 paren = 0 

281 elif word == '(': 

282 paren += 1 

283 elif word == ')': 

284 paren -= 1 

285 elif word == ',': 

286 if is_typedef and paren == 0: 

287 words_used.discard(previous_word) 

288 look_for_words.discard(previous_word) 

289 else: # word in COMMON_TYPES 

290 words_used.add(word) 

291 previous_word = word 

292 return words_used 

293 

294 

295class Parser(object): 

296 

297 def __init__(self): 

298 self._declarations = {} 

299 self._included_declarations = set() 

300 self._anonymous_counter = 0 

301 self._structnode2type = weakref.WeakKeyDictionary() 

302 self._options = {} 

303 self._int_constants = {} 

304 self._recomplete = [] 

305 self._uses_new_feature = None 

306 

307 def _parse(self, csource): 

308 csource, macros = _preprocess(csource) 

309 # XXX: for more efficiency we would need to poke into the 

310 # internals of CParser... the following registers the 

311 # typedefs, because their presence or absence influences the 

312 # parsing itself (but what they are typedef'ed to plays no role) 

313 ctn = _common_type_names(csource) 

314 typenames = [] 

315 for name in sorted(self._declarations): 

316 if name.startswith('typedef '): 

317 name = name[8:] 

318 typenames.append(name) 

319 ctn.discard(name) 

320 typenames += sorted(ctn) 

321 # 

322 csourcelines = [] 

323 csourcelines.append('# 1 "<cdef automatic initialization code>"') 

324 for typename in typenames: 

325 csourcelines.append('typedef int %s;' % typename) 

326 csourcelines.append('typedef int __dotdotdotint__, __dotdotdotfloat__,' 

327 ' __dotdotdot__;') 

328 # this forces pycparser to consider the following in the file 

329 # called <cdef source string> from line 1 

330 csourcelines.append('# 1 "%s"' % (CDEF_SOURCE_STRING,)) 

331 csourcelines.append(csource) 

332 fullcsource = '\n'.join(csourcelines) 

333 if lock is not None: 

334 lock.acquire() # pycparser is not thread-safe... 

335 try: 

336 ast = _get_parser().parse(fullcsource) 

337 except pycparser.c_parser.ParseError as e: 

338 self.convert_pycparser_error(e, csource) 

339 finally: 

340 if lock is not None: 

341 lock.release() 

342 # csource will be used to find buggy source text 

343 return ast, macros, csource 

344 

345 def _convert_pycparser_error(self, e, csource): 

346 # xxx look for "<cdef source string>:NUM:" at the start of str(e) 

347 # and interpret that as a line number. This will not work if 

348 # the user gives explicit ``# NUM "FILE"`` directives. 

349 line = None 

350 msg = str(e) 

351 match = re.match(r"%s:(\d+):" % (CDEF_SOURCE_STRING,), msg) 

352 if match: 

353 linenum = int(match.group(1), 10) 

354 csourcelines = csource.splitlines() 

355 if 1 <= linenum <= len(csourcelines): 

356 line = csourcelines[linenum-1] 

357 return line 

358 

359 def convert_pycparser_error(self, e, csource): 

360 line = self._convert_pycparser_error(e, csource) 

361 

362 msg = str(e) 

363 if line: 

364 msg = 'cannot parse "%s"\n%s' % (line.strip(), msg) 

365 else: 

366 msg = 'parse error\n%s' % (msg,) 

367 raise CDefError(msg) 

368 

369 def parse(self, csource, override=False, packed=False, pack=None, 

370 dllexport=False): 

371 if packed: 

372 if packed != True: 

373 raise ValueError("'packed' should be False or True; use " 

374 "'pack' to give another value") 

375 if pack: 

376 raise ValueError("cannot give both 'pack' and 'packed'") 

377 pack = 1 

378 elif pack: 

379 if pack & (pack - 1): 

380 raise ValueError("'pack' must be a power of two, not %r" % 

381 (pack,)) 

382 else: 

383 pack = 0 

384 prev_options = self._options 

385 try: 

386 self._options = {'override': override, 

387 'packed': pack, 

388 'dllexport': dllexport} 

389 self._internal_parse(csource) 

390 finally: 

391 self._options = prev_options 

392 

393 def _internal_parse(self, csource): 

394 ast, macros, csource = self._parse(csource) 

395 # add the macros 

396 self._process_macros(macros) 

397 # find the first "__dotdotdot__" and use that as a separator 

398 # between the repeated typedefs and the real csource 

399 iterator = iter(ast.ext) 

400 for decl in iterator: 

401 if decl.name == '__dotdotdot__': 

402 break 

403 else: 

404 assert 0 

405 current_decl = None 

406 # 

407 try: 

408 self._inside_extern_python = '__cffi_extern_python_stop' 

409 for decl in iterator: 

410 current_decl = decl 

411 if isinstance(decl, pycparser.c_ast.Decl): 

412 self._parse_decl(decl) 

413 elif isinstance(decl, pycparser.c_ast.Typedef): 

414 if not decl.name: 

415 raise CDefError("typedef does not declare any name", 

416 decl) 

417 quals = 0 

418 if (isinstance(decl.type.type, pycparser.c_ast.IdentifierType) and 

419 decl.type.type.names[-1].startswith('__dotdotdot')): 

420 realtype = self._get_unknown_type(decl) 

421 elif (isinstance(decl.type, pycparser.c_ast.PtrDecl) and 

422 isinstance(decl.type.type, pycparser.c_ast.TypeDecl) and 

423 isinstance(decl.type.type.type, 

424 pycparser.c_ast.IdentifierType) and 

425 decl.type.type.type.names[-1].startswith('__dotdotdot')): 

426 realtype = self._get_unknown_ptr_type(decl) 

427 else: 

428 realtype, quals = self._get_type_and_quals( 

429 decl.type, name=decl.name, partial_length_ok=True, 

430 typedef_example="*(%s *)0" % (decl.name,)) 

431 self._declare('typedef ' + decl.name, realtype, quals=quals) 

432 elif decl.__class__.__name__ == 'Pragma': 

433 pass # skip pragma, only in pycparser 2.15 

434 else: 

435 raise CDefError("unexpected <%s>: this construct is valid " 

436 "C but not valid in cdef()" % 

437 decl.__class__.__name__, decl) 

438 except CDefError as e: 

439 if len(e.args) == 1: 

440 e.args = e.args + (current_decl,) 

441 raise 

442 except FFIError as e: 

443 msg = self._convert_pycparser_error(e, csource) 

444 if msg: 

445 e.args = (e.args[0] + "\n *** Err: %s" % msg,) 

446 raise 

447 

448 def _add_constants(self, key, val): 

449 if key in self._int_constants: 

450 if self._int_constants[key] == val: 

451 return # ignore identical double declarations 

452 raise FFIError( 

453 "multiple declarations of constant: %s" % (key,)) 

454 self._int_constants[key] = val 

455 

456 def _add_integer_constant(self, name, int_str): 

457 int_str = int_str.lower().rstrip("ul") 

458 neg = int_str.startswith('-') 

459 if neg: 

460 int_str = int_str[1:] 

461 # "010" is not valid oct in py3 

462 if (int_str.startswith("0") and int_str != '0' 

463 and not int_str.startswith("0x")): 

464 int_str = "0o" + int_str[1:] 

465 pyvalue = int(int_str, 0) 

466 if neg: 

467 pyvalue = -pyvalue 

468 self._add_constants(name, pyvalue) 

469 self._declare('macro ' + name, pyvalue) 

470 

471 def _process_macros(self, macros): 

472 for key, value in macros.items(): 

473 value = value.strip() 

474 if _r_int_literal.match(value): 

475 self._add_integer_constant(key, value) 

476 elif value == '...': 

477 self._declare('macro ' + key, value) 

478 else: 

479 raise CDefError( 

480 'only supports one of the following syntax:\n' 

481 ' #define %s ... (literally dot-dot-dot)\n' 

482 ' #define %s NUMBER (with NUMBER an integer' 

483 ' constant, decimal/hex/octal)\n' 

484 'got:\n' 

485 ' #define %s %s' 

486 % (key, key, key, value)) 

487 

488 def _declare_function(self, tp, quals, decl): 

489 tp = self._get_type_pointer(tp, quals) 

490 if self._options.get('dllexport'): 

491 tag = 'dllexport_python ' 

492 elif self._inside_extern_python == '__cffi_extern_python_start': 

493 tag = 'extern_python ' 

494 elif self._inside_extern_python == '__cffi_extern_python_plus_c_start': 

495 tag = 'extern_python_plus_c ' 

496 else: 

497 tag = 'function ' 

498 self._declare(tag + decl.name, tp) 

499 

500 def _parse_decl(self, decl): 

501 node = decl.type 

502 if isinstance(node, pycparser.c_ast.FuncDecl): 

503 tp, quals = self._get_type_and_quals(node, name=decl.name) 

504 assert isinstance(tp, model.RawFunctionType) 

505 self._declare_function(tp, quals, decl) 

506 else: 

507 if isinstance(node, pycparser.c_ast.Struct): 

508 self._get_struct_union_enum_type('struct', node) 

509 elif isinstance(node, pycparser.c_ast.Union): 

510 self._get_struct_union_enum_type('union', node) 

511 elif isinstance(node, pycparser.c_ast.Enum): 

512 self._get_struct_union_enum_type('enum', node) 

513 elif not decl.name: 

514 raise CDefError("construct does not declare any variable", 

515 decl) 

516 # 

517 if decl.name: 

518 tp, quals = self._get_type_and_quals(node, 

519 partial_length_ok=True) 

520 if tp.is_raw_function: 

521 self._declare_function(tp, quals, decl) 

522 elif (tp.is_integer_type() and 

523 hasattr(decl, 'init') and 

524 hasattr(decl.init, 'value') and 

525 _r_int_literal.match(decl.init.value)): 

526 self._add_integer_constant(decl.name, decl.init.value) 

527 elif (tp.is_integer_type() and 

528 isinstance(decl.init, pycparser.c_ast.UnaryOp) and 

529 decl.init.op == '-' and 

530 hasattr(decl.init.expr, 'value') and 

531 _r_int_literal.match(decl.init.expr.value)): 

532 self._add_integer_constant(decl.name, 

533 '-' + decl.init.expr.value) 

534 elif (tp is model.void_type and 

535 decl.name.startswith('__cffi_extern_python_')): 

536 # hack: `extern "Python"` in the C source is replaced 

537 # with "void __cffi_extern_python_start;" and 

538 # "void __cffi_extern_python_stop;" 

539 self._inside_extern_python = decl.name 

540 else: 

541 if self._inside_extern_python !='__cffi_extern_python_stop': 

542 raise CDefError( 

543 "cannot declare constants or " 

544 "variables with 'extern \"Python\"'") 

545 if (quals & model.Q_CONST) and not tp.is_array_type: 

546 self._declare('constant ' + decl.name, tp, quals=quals) 

547 else: 

548 _warn_for_non_extern_non_static_global_variable(decl) 

549 self._declare('variable ' + decl.name, tp, quals=quals) 

550 

551 def parse_type(self, cdecl): 

552 return self.parse_type_and_quals(cdecl)[0] 

553 

554 def parse_type_and_quals(self, cdecl): 

555 ast, macros = self._parse('void __dummy(\n%s\n);' % cdecl)[:2] 

556 assert not macros 

557 exprnode = ast.ext[-1].type.args.params[0] 

558 if isinstance(exprnode, pycparser.c_ast.ID): 

559 raise CDefError("unknown identifier '%s'" % (exprnode.name,)) 

560 return self._get_type_and_quals(exprnode.type) 

561 

562 def _declare(self, name, obj, included=False, quals=0): 

563 if name in self._declarations: 

564 prevobj, prevquals = self._declarations[name] 

565 if prevobj is obj and prevquals == quals: 

566 return 

567 if not self._options.get('override'): 

568 raise FFIError( 

569 "multiple declarations of %s (for interactive usage, " 

570 "try cdef(xx, override=True))" % (name,)) 

571 assert '__dotdotdot__' not in name.split() 

572 self._declarations[name] = (obj, quals) 

573 if included: 

574 self._included_declarations.add(obj) 

575 

576 def _extract_quals(self, type): 

577 quals = 0 

578 if isinstance(type, (pycparser.c_ast.TypeDecl, 

579 pycparser.c_ast.PtrDecl)): 

580 if 'const' in type.quals: 

581 quals |= model.Q_CONST 

582 if 'volatile' in type.quals: 

583 quals |= model.Q_VOLATILE 

584 if 'restrict' in type.quals: 

585 quals |= model.Q_RESTRICT 

586 return quals 

587 

588 def _get_type_pointer(self, type, quals, declname=None): 

589 if isinstance(type, model.RawFunctionType): 

590 return type.as_function_pointer() 

591 if (isinstance(type, model.StructOrUnionOrEnum) and 

592 type.name.startswith('$') and type.name[1:].isdigit() and 

593 type.forcename is None and declname is not None): 

594 return model.NamedPointerType(type, declname, quals) 

595 return model.PointerType(type, quals) 

596 

597 def _get_type_and_quals(self, typenode, name=None, partial_length_ok=False, 

598 typedef_example=None): 

599 # first, dereference typedefs, if we have it already parsed, we're good 

600 if (isinstance(typenode, pycparser.c_ast.TypeDecl) and 

601 isinstance(typenode.type, pycparser.c_ast.IdentifierType) and 

602 len(typenode.type.names) == 1 and 

603 ('typedef ' + typenode.type.names[0]) in self._declarations): 

604 tp, quals = self._declarations['typedef ' + typenode.type.names[0]] 

605 quals |= self._extract_quals(typenode) 

606 return tp, quals 

607 # 

608 if isinstance(typenode, pycparser.c_ast.ArrayDecl): 

609 # array type 

610 if typenode.dim is None: 

611 length = None 

612 else: 

613 length = self._parse_constant( 

614 typenode.dim, partial_length_ok=partial_length_ok) 

615 # a hack: in 'typedef int foo_t[...][...];', don't use '...' as 

616 # the length but use directly the C expression that would be 

617 # generated by recompiler.py. This lets the typedef be used in 

618 # many more places within recompiler.py 

619 if typedef_example is not None: 

620 if length == '...': 

621 length = '_cffi_array_len(%s)' % (typedef_example,) 

622 typedef_example = "*" + typedef_example 

623 # 

624 tp, quals = self._get_type_and_quals(typenode.type, 

625 partial_length_ok=partial_length_ok, 

626 typedef_example=typedef_example) 

627 return model.ArrayType(tp, length), quals 

628 # 

629 if isinstance(typenode, pycparser.c_ast.PtrDecl): 

630 # pointer type 

631 itemtype, itemquals = self._get_type_and_quals(typenode.type) 

632 tp = self._get_type_pointer(itemtype, itemquals, declname=name) 

633 quals = self._extract_quals(typenode) 

634 return tp, quals 

635 # 

636 if isinstance(typenode, pycparser.c_ast.TypeDecl): 

637 quals = self._extract_quals(typenode) 

638 type = typenode.type 

639 if isinstance(type, pycparser.c_ast.IdentifierType): 

640 # assume a primitive type. get it from .names, but reduce 

641 # synonyms to a single chosen combination 

642 names = list(type.names) 

643 if names != ['signed', 'char']: # keep this unmodified 

644 prefixes = {} 

645 while names: 

646 name = names[0] 

647 if name in ('short', 'long', 'signed', 'unsigned'): 

648 prefixes[name] = prefixes.get(name, 0) + 1 

649 del names[0] 

650 else: 

651 break 

652 # ignore the 'signed' prefix below, and reorder the others 

653 newnames = [] 

654 for prefix in ('unsigned', 'short', 'long'): 

655 for i in range(prefixes.get(prefix, 0)): 

656 newnames.append(prefix) 

657 if not names: 

658 names = ['int'] # implicitly 

659 if names == ['int']: # but kill it if 'short' or 'long' 

660 if 'short' in prefixes or 'long' in prefixes: 

661 names = [] 

662 names = newnames + names 

663 ident = ' '.join(names) 

664 if ident == 'void': 

665 return model.void_type, quals 

666 if ident == '__dotdotdot__': 

667 raise FFIError(':%d: bad usage of "..."' % 

668 typenode.coord.line) 

669 tp0, quals0 = resolve_common_type(self, ident) 

670 return tp0, (quals | quals0) 

671 # 

672 if isinstance(type, pycparser.c_ast.Struct): 

673 # 'struct foobar' 

674 tp = self._get_struct_union_enum_type('struct', type, name) 

675 return tp, quals 

676 # 

677 if isinstance(type, pycparser.c_ast.Union): 

678 # 'union foobar' 

679 tp = self._get_struct_union_enum_type('union', type, name) 

680 return tp, quals 

681 # 

682 if isinstance(type, pycparser.c_ast.Enum): 

683 # 'enum foobar' 

684 tp = self._get_struct_union_enum_type('enum', type, name) 

685 return tp, quals 

686 # 

687 if isinstance(typenode, pycparser.c_ast.FuncDecl): 

688 # a function type 

689 return self._parse_function_type(typenode, name), 0 

690 # 

691 # nested anonymous structs or unions end up here 

692 if isinstance(typenode, pycparser.c_ast.Struct): 

693 return self._get_struct_union_enum_type('struct', typenode, name, 

694 nested=True), 0 

695 if isinstance(typenode, pycparser.c_ast.Union): 

696 return self._get_struct_union_enum_type('union', typenode, name, 

697 nested=True), 0 

698 # 

699 raise FFIError(":%d: bad or unsupported type declaration" % 

700 typenode.coord.line) 

701 

702 def _parse_function_type(self, typenode, funcname=None): 

703 params = list(getattr(typenode.args, 'params', [])) 

704 for i, arg in enumerate(params): 

705 if not hasattr(arg, 'type'): 

706 raise CDefError("%s arg %d: unknown type '%s'" 

707 " (if you meant to use the old C syntax of giving" 

708 " untyped arguments, it is not supported)" 

709 % (funcname or 'in expression', i + 1, 

710 getattr(arg, 'name', '?'))) 

711 ellipsis = ( 

712 len(params) > 0 and 

713 isinstance(params[-1].type, pycparser.c_ast.TypeDecl) and 

714 isinstance(params[-1].type.type, 

715 pycparser.c_ast.IdentifierType) and 

716 params[-1].type.type.names == ['__dotdotdot__']) 

717 if ellipsis: 

718 params.pop() 

719 if not params: 

720 raise CDefError( 

721 "%s: a function with only '(...)' as argument" 

722 " is not correct C" % (funcname or 'in expression')) 

723 args = [self._as_func_arg(*self._get_type_and_quals(argdeclnode.type)) 

724 for argdeclnode in params] 

725 if not ellipsis and args == [model.void_type]: 

726 args = [] 

727 result, quals = self._get_type_and_quals(typenode.type) 

728 # the 'quals' on the result type are ignored. HACK: we absure them 

729 # to detect __stdcall functions: we textually replace "__stdcall" 

730 # with "volatile volatile const" above. 

731 abi = None 

732 if hasattr(typenode.type, 'quals'): # else, probable syntax error anyway 

733 if typenode.type.quals[-3:] == ['volatile', 'volatile', 'const']: 

734 abi = '__stdcall' 

735 return model.RawFunctionType(tuple(args), result, ellipsis, abi) 

736 

737 def _as_func_arg(self, type, quals): 

738 if isinstance(type, model.ArrayType): 

739 return model.PointerType(type.item, quals) 

740 elif isinstance(type, model.RawFunctionType): 

741 return type.as_function_pointer()