parser.py revision 6657
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 cc = set([ 118 'ControllerFactory.cc', 119 'MachineType.cc']) 120 121 hh = set([ 122 'ControllerFactory.hh', 123 'MachineType.hh', 124 'Types.hh' ]) 125 126 for decl_list in self.decl_list_vec: 127 decl_list.files(hh, cc) 128 129 return hh, cc 130 131 t_ignore = '\t ' 132 133 # C or C++ comment (ignore) 134 def t_c_comment(self, t): 135 r'/\*(.|\n)*?\*/' 136 t.lexer.lineno += t.value.count('\n') 137 138 def t_cpp_comment(self, t): 139 r'//.*' 140 141 # Define a rule so we can track line numbers 142 def t_newline(self, t): 143 r'\n+' 144 t.lexer.lineno += len(t.value) 145 146 reserved = { 147 'global' : 'GLOBAL', 148 'machine' : 'MACHINE', 149 'in_port' : 'IN_PORT', 150 'out_port' : 'OUT_PORT', 151 'action' : 'ACTION', 152 'transition' : 'TRANS', 153 'structure' : 'STRUCT', 154 'external_type' : 'EXTERN_TYPE', 155 'enumeration' : 'ENUM', 156 'peek' : 'PEEK', 157 'enqueue' : 'ENQUEUE', 158 'copy_head' : 'COPY_HEAD', 159 'check_allocate' : 'CHECK_ALLOCATE', 160 'check_stop_slots' : 'CHECK_STOP_SLOTS', 161 'if' : 'IF', 162 'else' : 'ELSE', 163 'return' : 'RETURN', 164 'THIS' : 'THIS', 165 'CHIP' : 'CHIP', 166 'void' : 'VOID', 167 'new' : 'NEW', 168 } 169 170 literals = ':[]{}(),=' 171 172 tokens = [ 'EQ', 'NE', 'LT', 'GT', 'LE', 'GE', 173 'LEFTSHIFT', 'RIGHTSHIFT', 174 'NOT', 'AND', 'OR', 175 'PLUS', 'DASH', 'STAR', 'SLASH', 176 'DOUBLE_COLON', 'SEMI', 177 'ASSIGN', 'DOT', 178 'IDENT', 'LIT_BOOL', 'FLOATNUMBER', 'NUMBER', 'STRING' ] 179 tokens += reserved.values() 180 181 t_EQ = r'==' 182 t_NE = r'!=' 183 t_LT = r'<' 184 t_GT = r'>' 185 t_LE = r'<=' 186 t_GE = r'>=' 187 t_LEFTSHIFT = r'<<' 188 t_RIGHTSHIFT = r'>>' 189 t_NOT = r'!' 190 t_AND = r'&&' 191 t_OR = r'\|\|' 192 t_PLUS = r'\+' 193 t_DASH = r'-' 194 t_STAR = r'\*' 195 t_SLASH = r'/' 196 t_DOUBLE_COLON = r'::' 197 t_SEMI = r';' 198 t_ASSIGN = r':=' 199 t_DOT = r'\.' 200 201 precedence = ( 202 ('left', 'AND', 'OR'), 203 ('left', 'EQ', 'NE'), 204 ('left', 'LT', 'GT', 'LE', 'GE'), 205 ('left', 'RIGHTSHIFT', 'LEFTSHIFT'), 206 ('left', 'PLUS', 'DASH'), 207 ('left', 'STAR', 'SLASH'), 208 ('right', 'NOT', 'UMINUS'), 209 ) 210 211 def t_IDENT(self, t): 212 r'[a-zA-Z_][a-zA-Z_0-9]*' 213 if t.value == 'true': 214 t.type = 'LIT_BOOL' 215 t.value = True 216 return t 217 218 if t.value == 'false': 219 t.type = 'LIT_BOOL' 220 t.value = False 221 return t 222 223 # Check for reserved words 224 t.type = self.reserved.get(t.value, 'IDENT') 225 return t 226 227 def t_FLOATNUMBER(self, t): 228 '[0-9]+[.][0-9]+' 229 try: 230 t.value = float(t.value) 231 except ValueError: 232 raise TokenError("Illegal float", t) 233 return t 234 235 def t_NUMBER(self, t): 236 r'[0-9]+' 237 try: 238 t.value = int(t.value) 239 except ValueError: 240 raise TokenError("Illegal number", t) 241 return t 242 243 def t_STRING1(self, t): 244 r'\"[^"\n]*\"' 245 t.type = 'STRING' 246 t.value = t.value[1:-1] 247 return t 248 249 def t_STRING2(self, t): 250 r"\'[^'\n]*\'" 251 t.type = 'STRING' 252 t.value = t.value[1:-1] 253 return t 254 255 def p_file(self, p): 256 "file : decls" 257 p[0] = p[1] 258 259 def p_empty(self, p): 260 "empty :" 261 262 def p_decls(self, p): 263 "decls : declsx" 264 p[0] = ast.DeclListAST(self, p[1]) 265 266 def p_declsx__list(self, p): 267 "declsx : decl declsx" 268 p[0] = [ p[1] ] + p[2] 269 270 def p_declsx__none(self, p): 271 "declsx : empty" 272 p[0] = [] 273 274 def p_decl__machine(self, p): 275 "decl : MACHINE '(' ident pairs ')' ':' params '{' decls '}'" 276 p[0] = ast.MachineAST(self, p[3], p[4], p[7], p[9]) 277 278 def p_decl__action(self, p): 279 "decl : ACTION '(' ident pairs ')' statements" 280 p[0] = ast.ActionDeclAST(self, p[3], p[4], p[6]) 281 282 def p_decl__in_port(self, p): 283 "decl : IN_PORT '(' ident ',' type ',' var pairs ')' statements" 284 p[0] = ast.InPortDeclAST(self, p[3], p[5], p[7], p[8], p[10]) 285 286 def p_decl__out_port(self, p): 287 "decl : OUT_PORT '(' ident ',' type ',' var pairs ')' SEMI" 288 p[0] = ast.OutPortDeclAST(self, p[3], p[5], p[7], p[8]) 289 290 def p_decl__trans0(self, p): 291 "decl : TRANS '(' idents ',' idents ',' ident pairs ')' idents" 292 p[0] = ast.TransitionDeclAST(self, p[3], p[5], p[7], p[8], p[10]) 293 294 def p_decl__trans1(self, p): 295 "decl : TRANS '(' idents ',' idents pairs ')' idents" 296 p[0] = ast.TransitionDeclAST(self, p[3], p[5], None, p[6], p[8]) 297 298 def p_decl__extern0(self, p): 299 "decl : EXTERN_TYPE '(' type pairs ')' SEMI" 300 p[4]["external"] = "yes" 301 p[0] = ast.TypeDeclAST(self, p[3], p[4], []) 302 303 def p_decl__extern1(self, p): 304 "decl : EXTERN_TYPE '(' type pairs ')' '{' type_methods '}'" 305 p[4]["external"] = "yes" 306 p[0] = ast.TypeDeclAST(self, p[3], p[4], p[7]) 307 308 def p_decl__global(self, p): 309 "decl : GLOBAL '(' type pairs ')' '{' type_members '}'" 310 p[4]["global"] = "yes" 311 p[0] = ast.TypeDeclAST(self, p[3], p[4], p[7]) 312 313 def p_decl__struct(self, p): 314 "decl : STRUCT '(' type pairs ')' '{' type_members '}'" 315 p[0] = ast.TypeDeclAST(self, p[3], p[4], p[7]) 316 317 def p_decl__enum(self, p): 318 "decl : ENUM '(' type pairs ')' '{' type_enums '}'" 319 p[4]["enumeration"] = "yes" 320 p[0] = ast.EnumDeclAST(self, p[3], p[4], p[7]) 321 322 def p_decl__object(self, p): 323 "decl : type ident pairs SEMI" 324 p[0] = ast.ObjDeclAST(self, p[1], p[2], p[3]) 325 326 def p_decl__func_decl(self, p): 327 """decl : void ident '(' params ')' pairs SEMI 328 | type ident '(' params ')' pairs SEMI""" 329 p[0] = ast.FuncDeclAST(self, p[1], p[2], p[4], p[6], None) 330 331 def p_decl__func_def(self, p): 332 """decl : void ident '(' params ')' pairs statements 333 | type ident '(' params ')' pairs statements""" 334 p[0] = ast.FuncDeclAST(self, p[1], p[2], p[4], p[6], p[7]) 335 336 # Type fields 337 def p_type_members__list(self, p): 338 "type_members : type_member type_members" 339 p[0] = [ p[1] ] + p[2] 340 341 def p_type_members__empty(self, p): 342 "type_members : empty" 343 p[0] = [] 344 345 def p_type_member__1(self, p): 346 "type_member : type ident pairs SEMI" 347 p[0] = ast.TypeFieldMemberAST(self, p[1], p[2], p[3], None) 348 349 def p_type_member__2(self, p): 350 "type_member : type ident ASSIGN expr SEMI" 351 p[0] = ast.TypeFieldMemberAST(self, p[1], p[2], 352 ast.PairListAST(self), p[4]) 353 354 # Methods 355 def p_type_methods__list(self, p): 356 "type_methods : type_method type_methods" 357 p[0] = [ p[1] ] + p[2] 358 359 def p_type_methods(self, p): 360 "type_methods : empty" 361 p[0] = [] 362 363 def p_type_method(self, p): 364 "type_method : type_or_void ident '(' types ')' pairs SEMI" 365 p[0] = ast.TypeFieldMethodAST(self, p[1], p[2], p[4], p[6]) 366 367 # Enum fields 368 def p_type_enums__list(self, p): 369 "type_enums : type_enum type_enums" 370 p[0] = [ p[1] ] + p[2] 371 372 def p_type_enums__empty(self, p): 373 "type_enums : empty" 374 p[0] = [] 375 376 def p_type_enum(self, p): 377 "type_enum : ident pairs SEMI" 378 p[0] = ast.TypeFieldEnumAST(self, p[1], p[2]) 379 380 # Type 381 def p_types__multiple(self, p): 382 "types : type ',' types" 383 p[0] = [ p[1] ] + p[3] 384 385 def p_types__one(self, p): 386 "types : type" 387 p[0] = [ p[1] ] 388 389 def p_types__empty(self, p): 390 "types : empty" 391 p[0] = [] 392 393 def p_type(self, p): 394 "type : ident" 395 p[0] = ast.TypeAST(self, p[1]) 396 397 def p_void(self, p): 398 "void : VOID" 399 p[0] = ast.TypeAST(self, p[1]) 400 401 def p_type_or_void(self, p): 402 """type_or_void : type 403 | void""" 404 p[0] = p[1] 405 406 # Formal Param 407 def p_params__many(self, p): 408 "params : param ',' params" 409 p[0] = [ p[1] ] + p[3] 410 411 def p_params__one(self, p): 412 "params : param" 413 p[0] = [ p[1] ] 414 415 def p_params__none(self, p): 416 "params : empty" 417 p[0] = [] 418 419 def p_param(self, p): 420 "param : type ident" 421 p[0] = ast.FormalParamAST(self, p[1], p[2]) 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 ')' statements" 520 p[0] = ast.PeekStatementAST(self, p[3], p[5], p[7], "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