parser.py revision 6877:2a1a3d916ca8
1# Copyright (c) 2009 The Hewlett-Packard Development Company 2# All rights reserved. 3# 4# Redistribution and use in source and binary forms, with or without 5# modification, are permitted provided that the following conditions are 6# met: redistributions of source code must retain the above copyright 7# notice, this list of conditions and the following disclaimer; 8# redistributions in binary form must reproduce the above copyright 9# notice, this list of conditions and the following disclaimer in the 10# documentation and/or other materials provided with the distribution; 11# neither the name of the copyright holders nor the names of its 12# contributors may be used to endorse or promote products derived from 13# this software without specific prior written permission. 14# 15# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 16# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 17# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 18# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 19# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 20# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 21# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 22# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 23# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 24# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 25# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 26# 27# Authors: Nathan Binkert 28 29import os.path 30import re 31import sys 32 33from m5.util.grammar import Grammar, TokenError, ParseError 34 35import slicc.ast as ast 36import slicc.util as util 37from slicc.symbols import SymbolTable 38 39def read_slicc(sources): 40 if not isinstance(sources, (list,tuple)): 41 sources = [ sources ] 42 43 for source in sources: 44 for sm_file in file(source, "r"): 45 sm_file = sm_file.strip() 46 if not sm_file: 47 continue 48 if sm_file.startswith("#"): 49 continue 50 yield sm_file 51 52class SLICC(Grammar): 53 def __init__(self, **kwargs): 54 super(SLICC, self).__init__(**kwargs) 55 self.decl_list_vec = [] 56 self.current_file = None 57 self.symtab = SymbolTable() 58 59 def parse(self, filename): 60 self.current_file = filename 61 f = file(filename, 'r') 62 text = f.read() 63 try: 64 decl_list = super(SLICC, self).parse(text) 65 except (TokenError, ParseError), e: 66 sys.exit("%s: %s:%d" % (e, filename, e.token.lineno)) 67 self.decl_list_vec.append(decl_list) 68 self.current_file = None 69 70 def _load(self, *filenames): 71 filenames = list(filenames) 72 while filenames: 73 f = filenames.pop(0) 74 if isinstance(f, (list, tuple)): 75 filenames[0:0] = list(f) 76 continue 77 78 yield f 79 if f.endswith(".slicc"): 80 dirname,basename = os.path.split(f) 81 filenames[0:0] = [ os.path.join(dirname, x) \ 82 for x in read_slicc(f)] 83 else: 84 assert f.endswith(".sm") 85 self.parse(f) 86 87 def load(self, *filenames, **kwargs): 88 verbose = kwargs.pop("verbose", False) 89 if kwargs: 90 raise TypeError 91 92 gen = self._load(*filenames) 93 if verbose: 94 return gen 95 else: 96 # Run out the generator if we don't want the verbosity 97 for foo in gen: 98 pass 99 100 def findMachines(self): 101 for decl_list in self.decl_list_vec: 102 decl_list.findMachines() 103 104 def generate(self): 105 for decl_list in self.decl_list_vec: 106 decl_list.generate() 107 108 def writeCodeFiles(self, code_path): 109 util.makeDir(code_path) 110 self.symtab.writeCodeFiles(code_path) 111 112 def writeHTMLFiles(self, code_path): 113 util.makeDir(code_path) 114 self.symtab.writeHTMLFiles(code_path) 115 116 def files(self): 117 f = set([ 118 'MachineType.cc', 119 'MachineType.hh', 120 'Types.hh' ]) 121 122 for decl_list in self.decl_list_vec: 123 f |= decl_list.files() 124 125 return f 126 127 t_ignore = '\t ' 128 129 # C or C++ comment (ignore) 130 def t_c_comment(self, t): 131 r'/\*(.|\n)*?\*/' 132 t.lexer.lineno += t.value.count('\n') 133 134 def t_cpp_comment(self, t): 135 r'//.*' 136 137 # Define a rule so we can track line numbers 138 def t_newline(self, t): 139 r'\n+' 140 t.lexer.lineno += len(t.value) 141 142 reserved = { 143 'global' : 'GLOBAL', 144 'machine' : 'MACHINE', 145 'in_port' : 'IN_PORT', 146 'out_port' : 'OUT_PORT', 147 'action' : 'ACTION', 148 'transition' : 'TRANS', 149 'structure' : 'STRUCT', 150 'external_type' : 'EXTERN_TYPE', 151 'enumeration' : 'ENUM', 152 'peek' : 'PEEK', 153 'enqueue' : 'ENQUEUE', 154 'copy_head' : 'COPY_HEAD', 155 'check_allocate' : 'CHECK_ALLOCATE', 156 'check_stop_slots' : 'CHECK_STOP_SLOTS', 157 'if' : 'IF', 158 'else' : 'ELSE', 159 'return' : 'RETURN', 160 'THIS' : 'THIS', 161 'CHIP' : 'CHIP', 162 'void' : 'VOID', 163 'new' : 'NEW', 164 } 165 166 literals = ':[]{}(),=' 167 168 tokens = [ 'EQ', 'NE', 'LT', 'GT', 'LE', 'GE', 169 'LEFTSHIFT', 'RIGHTSHIFT', 170 'NOT', 'AND', 'OR', 171 'PLUS', 'DASH', 'STAR', 'SLASH', 172 'DOUBLE_COLON', 'SEMI', 173 'ASSIGN', 'DOT', 174 'IDENT', 'LIT_BOOL', 'FLOATNUMBER', 'NUMBER', 'STRING' ] 175 tokens += reserved.values() 176 177 t_EQ = r'==' 178 t_NE = r'!=' 179 t_LT = r'<' 180 t_GT = r'>' 181 t_LE = r'<=' 182 t_GE = r'>=' 183 t_LEFTSHIFT = r'<<' 184 t_RIGHTSHIFT = r'>>' 185 t_NOT = r'!' 186 t_AND = r'&&' 187 t_OR = r'\|\|' 188 t_PLUS = r'\+' 189 t_DASH = r'-' 190 t_STAR = r'\*' 191 t_SLASH = r'/' 192 t_DOUBLE_COLON = r'::' 193 t_SEMI = r';' 194 t_ASSIGN = r':=' 195 t_DOT = r'\.' 196 197 precedence = ( 198 ('left', 'AND', 'OR'), 199 ('left', 'EQ', 'NE'), 200 ('left', 'LT', 'GT', 'LE', 'GE'), 201 ('left', 'RIGHTSHIFT', 'LEFTSHIFT'), 202 ('left', 'PLUS', 'DASH'), 203 ('left', 'STAR', 'SLASH'), 204 ('right', 'NOT', 'UMINUS'), 205 ) 206 207 def t_IDENT(self, t): 208 r'[a-zA-Z_][a-zA-Z_0-9]*' 209 if t.value == 'true': 210 t.type = 'LIT_BOOL' 211 t.value = True 212 return t 213 214 if t.value == 'false': 215 t.type = 'LIT_BOOL' 216 t.value = False 217 return t 218 219 # Check for reserved words 220 t.type = self.reserved.get(t.value, 'IDENT') 221 return t 222 223 def t_FLOATNUMBER(self, t): 224 '[0-9]+[.][0-9]+' 225 try: 226 t.value = float(t.value) 227 except ValueError: 228 raise TokenError("Illegal float", t) 229 return t 230 231 def t_NUMBER(self, t): 232 r'[0-9]+' 233 try: 234 t.value = int(t.value) 235 except ValueError: 236 raise TokenError("Illegal number", t) 237 return t 238 239 def t_STRING1(self, t): 240 r'\"[^"\n]*\"' 241 t.type = 'STRING' 242 t.value = t.value[1:-1] 243 return t 244 245 def t_STRING2(self, t): 246 r"\'[^'\n]*\'" 247 t.type = 'STRING' 248 t.value = t.value[1:-1] 249 return t 250 251 def p_file(self, p): 252 "file : decls" 253 p[0] = p[1] 254 255 def p_empty(self, p): 256 "empty :" 257 258 def p_decls(self, p): 259 "decls : declsx" 260 p[0] = ast.DeclListAST(self, p[1]) 261 262 def p_declsx__list(self, p): 263 "declsx : decl declsx" 264 p[0] = [ p[1] ] + p[2] 265 266 def p_declsx__none(self, p): 267 "declsx : empty" 268 p[0] = [] 269 270 def p_decl__machine(self, p): 271 "decl : MACHINE '(' ident pairs ')' ':' params '{' decls '}'" 272 p[0] = ast.MachineAST(self, p[3], p[4], p[7], p[9]) 273 274 def p_decl__action(self, p): 275 "decl : ACTION '(' ident pairs ')' statements" 276 p[0] = ast.ActionDeclAST(self, p[3], p[4], p[6]) 277 278 def p_decl__in_port(self, p): 279 "decl : IN_PORT '(' ident ',' type ',' var pairs ')' statements" 280 p[0] = ast.InPortDeclAST(self, p[3], p[5], p[7], p[8], p[10]) 281 282 def p_decl__out_port(self, p): 283 "decl : OUT_PORT '(' ident ',' type ',' var pairs ')' SEMI" 284 p[0] = ast.OutPortDeclAST(self, p[3], p[5], p[7], p[8]) 285 286 def p_decl__trans0(self, p): 287 "decl : TRANS '(' idents ',' idents ',' ident pairs ')' idents" 288 p[0] = ast.TransitionDeclAST(self, p[3], p[5], p[7], p[8], p[10]) 289 290 def p_decl__trans1(self, p): 291 "decl : TRANS '(' idents ',' idents pairs ')' idents" 292 p[0] = ast.TransitionDeclAST(self, p[3], p[5], None, p[6], p[8]) 293 294 def p_decl__extern0(self, p): 295 "decl : EXTERN_TYPE '(' type pairs ')' SEMI" 296 p[4]["external"] = "yes" 297 p[0] = ast.TypeDeclAST(self, p[3], p[4], []) 298 299 def p_decl__extern1(self, p): 300 "decl : EXTERN_TYPE '(' type pairs ')' '{' type_methods '}'" 301 p[4]["external"] = "yes" 302 p[0] = ast.TypeDeclAST(self, p[3], p[4], p[7]) 303 304 def p_decl__global(self, p): 305 "decl : GLOBAL '(' type pairs ')' '{' type_members '}'" 306 p[4]["global"] = "yes" 307 p[0] = ast.TypeDeclAST(self, p[3], p[4], p[7]) 308 309 def p_decl__struct(self, p): 310 "decl : STRUCT '(' type pairs ')' '{' type_members '}'" 311 p[0] = ast.TypeDeclAST(self, p[3], p[4], p[7]) 312 313 def p_decl__enum(self, p): 314 "decl : ENUM '(' type pairs ')' '{' type_enums '}'" 315 p[4]["enumeration"] = "yes" 316 p[0] = ast.EnumDeclAST(self, p[3], p[4], p[7]) 317 318 def p_decl__object(self, p): 319 "decl : type ident pairs SEMI" 320 p[0] = ast.ObjDeclAST(self, p[1], p[2], p[3]) 321 322 def p_decl__func_decl(self, p): 323 """decl : void ident '(' params ')' pairs SEMI 324 | type ident '(' params ')' pairs SEMI""" 325 p[0] = ast.FuncDeclAST(self, p[1], p[2], p[4], p[6], None) 326 327 def p_decl__func_def(self, p): 328 """decl : void ident '(' params ')' pairs statements 329 | type ident '(' params ')' pairs statements""" 330 p[0] = ast.FuncDeclAST(self, p[1], p[2], p[4], p[6], p[7]) 331 332 # Type fields 333 def p_type_members__list(self, p): 334 "type_members : type_member type_members" 335 p[0] = [ p[1] ] + p[2] 336 337 def p_type_members__empty(self, p): 338 "type_members : empty" 339 p[0] = [] 340 341 def p_type_member__1(self, p): 342 "type_member : type ident pairs SEMI" 343 p[0] = ast.TypeFieldMemberAST(self, p[1], p[2], p[3], None) 344 345 def p_type_member__2(self, p): 346 "type_member : type ident ASSIGN expr SEMI" 347 p[0] = ast.TypeFieldMemberAST(self, p[1], p[2], 348 ast.PairListAST(self), p[4]) 349 350 # Methods 351 def p_type_methods__list(self, p): 352 "type_methods : type_method type_methods" 353 p[0] = [ p[1] ] + p[2] 354 355 def p_type_methods(self, p): 356 "type_methods : empty" 357 p[0] = [] 358 359 def p_type_method(self, p): 360 "type_method : type_or_void ident '(' types ')' pairs SEMI" 361 p[0] = ast.TypeFieldMethodAST(self, p[1], p[2], p[4], p[6]) 362 363 # Enum fields 364 def p_type_enums__list(self, p): 365 "type_enums : type_enum type_enums" 366 p[0] = [ p[1] ] + p[2] 367 368 def p_type_enums__empty(self, p): 369 "type_enums : empty" 370 p[0] = [] 371 372 def p_type_enum(self, p): 373 "type_enum : ident pairs SEMI" 374 p[0] = ast.TypeFieldEnumAST(self, p[1], p[2]) 375 376 # Type 377 def p_types__multiple(self, p): 378 "types : type ',' types" 379 p[0] = [ p[1] ] + p[3] 380 381 def p_types__one(self, p): 382 "types : type" 383 p[0] = [ p[1] ] 384 385 def p_types__empty(self, p): 386 "types : empty" 387 p[0] = [] 388 389 def p_type(self, p): 390 "type : ident" 391 p[0] = ast.TypeAST(self, p[1]) 392 393 def p_void(self, p): 394 "void : VOID" 395 p[0] = ast.TypeAST(self, p[1]) 396 397 def p_type_or_void(self, p): 398 """type_or_void : type 399 | void""" 400 p[0] = p[1] 401 402 # Formal Param 403 def p_params__many(self, p): 404 "params : param ',' params" 405 p[0] = [ p[1] ] + p[3] 406 407 def p_params__one(self, p): 408 "params : param" 409 p[0] = [ p[1] ] 410 411 def p_params__none(self, p): 412 "params : empty" 413 p[0] = [] 414 415 def p_param(self, p): 416 "param : type ident" 417 p[0] = ast.FormalParamAST(self, p[1], p[2]) 418 419 def p_param__default(self, p): 420 "param : type ident '=' NUMBER" 421 p[0] = ast.FormalParamAST(self, p[1], p[2], p[4]) 422 423 # Idents and lists 424 def p_idents__braced(self, p): 425 "idents : '{' identx '}'" 426 p[0] = p[2] 427 428 def p_idents__bare(self, p): 429 "idents : ident" 430 p[0] = [ p[1] ] 431 432 def p_identx__multiple_1(self, p): 433 """identx : ident SEMI identx 434 | ident ',' identx""" 435 p[0] = [ p[1] ] + p[3] 436 437 def p_identx__multiple_2(self, p): 438 "identx : ident identx" 439 p[0] = [ p[1] ] + p[2] 440 441 def p_identx__single(self, p): 442 "identx : empty" 443 p[0] = [ ] 444 445 def p_ident(self, p): 446 "ident : IDENT" 447 p[0] = p[1] 448 449 # Pair and pair lists 450 def p_pairs__list(self, p): 451 "pairs : ',' pairsx" 452 p[0] = p[2] 453 454 def p_pairs__empty(self, p): 455 "pairs : empty" 456 p[0] = ast.PairListAST(self) 457 458 def p_pairsx__many(self, p): 459 "pairsx : pair ',' pairsx" 460 p[0] = p[3] 461 p[0].addPair(p[1]) 462 463 def p_pairsx__one(self, p): 464 "pairsx : pair" 465 p[0] = ast.PairListAST(self) 466 p[0].addPair(p[1]) 467 468 def p_pair__assign(self, p): 469 """pair : ident '=' STRING 470 | ident '=' ident""" 471 p[0] = ast.PairAST(self, p[1], p[3]) 472 473 def p_pair__literal(self, p): 474 "pair : STRING" 475 p[0] = ast.PairAST(self, "short", p[1]) 476 477 # Below are the rules for action descriptions 478 def p_statements__inner(self, p): 479 "statements : '{' statements_inner '}'" 480 p[0] = ast.StatementListAST(self, p[2]) 481 482 def p_statements__none(self, p): 483 "statements : '{' '}'" 484 p[0] = ast.StatementListAST(self, []) 485 486 def p_statements_inner__many(self, p): 487 "statements_inner : statement statements_inner" 488 p[0] = [ p[1] ] + p[2] 489 490 def p_statements_inner__one(self, p): 491 "statements_inner : statement" 492 p[0] = [ p[1] ] 493 494 def p_exprs__multiple(self, p): 495 "exprs : expr ',' exprs" 496 p[0] = [ p[1] ] + p[3] 497 498 def p_exprs__one(self, p): 499 "exprs : expr" 500 p[0] = [ p[1] ] 501 502 def p_exprs__empty(self, p): 503 "exprs : empty""" 504 p[0] = [] 505 506 def p_statement__expression(self, p): 507 "statement : expr SEMI" 508 p[0] = ast.ExprStatementAST(self, p[1]) 509 510 def p_statement__assign(self, p): 511 "statement : expr ASSIGN expr SEMI" 512 p[0] = ast.AssignStatementAST(self, p[1], p[3]) 513 514 def p_statement__enqueue(self, p): 515 "statement : ENQUEUE '(' var ',' type pairs ')' statements" 516 p[0] = ast.EnqueueStatementAST(self, p[3], p[5], p[6], p[8]) 517 518 def p_statement__peek(self, p): 519 "statement : PEEK '(' var ',' type pairs ')' statements" 520 p[0] = ast.PeekStatementAST(self, p[3], p[5], p[6], p[8], "peek") 521 522 def p_statement__copy_head(self, p): 523 "statement : COPY_HEAD '(' var ',' var pairs ')' SEMI" 524 p[0] = ast.CopyHeadStatementAST(self, p[3], p[5], p[6]) 525 526 def p_statement__check_allocate(self, p): 527 "statement : CHECK_ALLOCATE '(' var ')' SEMI" 528 p[0] = ast.CheckAllocateStatementAST(self, p[3]) 529 530 def p_statement__check_stop(self, p): 531 "statement : CHECK_STOP_SLOTS '(' var ',' STRING ',' STRING ')' SEMI" 532 p[0] = ast.CheckStopStatementAST(self, p[3], p[5], p[7]) 533 534 def p_statement__return(self, p): 535 "statement : RETURN expr SEMI" 536 p[0] = ast.ReturnStatementAST(self, p[2]) 537 538 def p_statement__if(self, p): 539 "statement : if_statement" 540 p[0] = p[1] 541 542 def p_if_statement__if(self, p): 543 "if_statement : IF '(' expr ')' statements" 544 p[0] = ast.IfStatementAST(self, p[3], p[5], None) 545 546 def p_if_statement__if_else(self, p): 547 "if_statement : IF '(' expr ')' statements ELSE statements" 548 p[0] = ast.IfStatementAST(self, p[3], p[5], p[7]) 549 550 def p_statement__if_else_if(self, p): 551 "if_statement : IF '(' expr ')' statements ELSE if_statement" 552 p[0] = ast.IfStatementAST(self, p[3], p[5], 553 ast.StatementListAST(self, p[7])) 554 555 def p_expr__var(self, p): 556 "aexpr : var" 557 p[0] = p[1] 558 559 def p_expr__literal(self, p): 560 "aexpr : literal" 561 p[0] = p[1] 562 563 def p_expr__enumeration(self, p): 564 "aexpr : enumeration" 565 p[0] = p[1] 566 567 def p_expr__func_call(self, p): 568 "aexpr : ident '(' exprs ')'" 569 p[0] = ast.FuncCallExprAST(self, p[1], p[3]) 570 571 def p_expr__new(self, p): 572 "aexpr : NEW type" 573 p[0] = ast.NewExprAST(self, p[2]) 574 575 # globally access a local chip component and call a method 576 def p_expr__local_chip_method(self, p): 577 "aexpr : THIS DOT var '[' expr ']' DOT var DOT ident '(' exprs ')'" 578 p[0] = ast.LocalChipMethodAST(self, p[3], p[5], p[8], p[10], p[12]) 579 580 # globally access a local chip component and access a data member 581 def p_expr__local_chip_member(self, p): 582 "aexpr : THIS DOT var '[' expr ']' DOT var DOT field" 583 p[0] = ast.LocalChipMemberAST(self, p[3], p[5], p[8], p[10]) 584 585 # globally access a specified chip component and call a method 586 def p_expr__specified_chip_method(self, p): 587 "aexpr : CHIP '[' expr ']' DOT var '[' expr ']' DOT var DOT ident '(' exprs ')'" 588 p[0] = ast.SpecifiedChipMethodAST(self, p[3], p[6], p[8], p[11], p[13], 589 p[15]) 590 591 # globally access a specified chip component and access a data member 592 def p_expr__specified_chip_member(self, p): 593 "aexpr : CHIP '[' expr ']' DOT var '[' expr ']' DOT var DOT field" 594 p[0] = ast.SpecifiedChipMemberAST(self, p[3], p[6], p[8], p[11], p[13]) 595 596 def p_expr__member(self, p): 597 "aexpr : aexpr DOT ident" 598 p[0] = ast.MemberExprAST(self, p[1], p[3]) 599 600 def p_expr__member_method_call(self, p): 601 "aexpr : aexpr DOT ident '(' exprs ')'" 602 p[0] = ast.MemberMethodCallExprAST(self, p[1], p[3], p[5]) 603 604 def p_expr__member_method_call_lookup(self, p): 605 "aexpr : aexpr '[' exprs ']'" 606 p[0] = ast.MemberMethodCallExprAST(self, p[1], "lookup", p[3]) 607 608 def p_expr__class_method_call(self, p): 609 "aexpr : type DOUBLE_COLON ident '(' exprs ')'" 610 p[0] = ast.ClassMethodCallExprAST(self, p[1], p[3], p[5]) 611 612 def p_expr__aexpr(self, p): 613 "expr : aexpr" 614 p[0] = p[1] 615 616 def p_expr__binary_op(self, p): 617 """expr : expr STAR expr 618 | expr SLASH expr 619 | expr PLUS expr 620 | expr DASH expr 621 | expr LT expr 622 | expr GT expr 623 | expr LE expr 624 | expr GE expr 625 | expr EQ expr 626 | expr NE expr 627 | expr AND expr 628 | expr OR expr 629 | expr RIGHTSHIFT expr 630 | expr LEFTSHIFT expr""" 631 p[0] = ast.InfixOperatorExprAST(self, p[1], p[2], p[3]) 632 633 # FIXME - unary not 634 def p_expr__unary_op(self, p): 635 """expr : NOT expr 636 | DASH expr %prec UMINUS""" 637 p[0] = PrefixOperatorExpr(p[1], p[2]) 638 639 def p_expr__parens(self, p): 640 "aexpr : '(' expr ')'" 641 p[0] = p[2] 642 643 def p_literal__string(self, p): 644 "literal : STRING" 645 p[0] = ast.LiteralExprAST(self, p[1], "string") 646 647 def p_literal__number(self, p): 648 "literal : NUMBER" 649 p[0] = ast.LiteralExprAST(self, p[1], "int") 650 651 def p_literal__float(self, p): 652 "literal : FLOATNUMBER" 653 p[0] = ast.LiteralExprAST(self, p[1], "int") 654 655 def p_literal__bool(self, p): 656 "literal : LIT_BOOL" 657 p[0] = ast.LiteralExprAST(self, p[1], "bool") 658 659 def p_enumeration(self, p): 660 "enumeration : ident ':' ident" 661 p[0] = ast.EnumExprAST(self, ast.TypeAST(self, p[1]), p[3]) 662 663 def p_var(self, p): 664 "var : ident" 665 p[0] = ast.VarExprAST(self, p[1]) 666 667 def p_field(self, p): 668 "field : ident" 669 p[0] = p[1] 670