1 /* 2 * Copyright (c) 1988, 1989, 1990 The Regents of the University of California. 3 * Copyright (c) 1988, 1989 by Adam de Boor 4 * Copyright (c) 1989 by Berkeley Softworks 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to Berkeley by 8 * Adam de Boor. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. All advertising materials mentioning features or use of this software 19 * must display the following acknowledgement: 20 * This product includes software developed by the University of 21 * California, Berkeley and its contributors. 22 * 4. Neither the name of the University nor the names of its contributors 23 * may be used to endorse or promote products derived from this software 24 * without specific prior written permission. 25 * 26 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 28 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 29 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 30 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 31 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 32 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 36 * SUCH DAMAGE. 37 */ 38 39 #ifndef lint 40 /* from: static char sccsid[] = "@(#)cond.c 5.6 (Berkeley) 6/1/90"; */ 41 static char *rcsid = "$Id: cond.c,v 1.4 1994/03/05 00:34:39 cgd Exp $"; 42 #endif /* not lint */ 43 44 /*- 45 * cond.c -- 46 * Functions to handle conditionals in a makefile. 47 * 48 * Interface: 49 * Cond_Eval Evaluate the conditional in the passed line. 50 * 51 */ 52 53 #include <ctype.h> 54 #include <math.h> 55 #include "make.h" 56 #include "hash.h" 57 #include "dir.h" 58 #include "buf.h" 59 60 /* 61 * The parsing of conditional expressions is based on this grammar: 62 * E -> F || E 63 * E -> F 64 * F -> T && F 65 * F -> T 66 * T -> defined(variable) 67 * T -> make(target) 68 * T -> exists(file) 69 * T -> empty(varspec) 70 * T -> target(name) 71 * T -> symbol 72 * T -> $(varspec) op value 73 * T -> $(varspec) == "string" 74 * T -> $(varspec) != "string" 75 * T -> ( E ) 76 * T -> ! T 77 * op -> == | != | > | < | >= | <= 78 * 79 * 'symbol' is some other symbol to which the default function (condDefProc) 80 * is applied. 81 * 82 * Tokens are scanned from the 'condExpr' string. The scanner (CondToken) 83 * will return And for '&' and '&&', Or for '|' and '||', Not for '!', 84 * LParen for '(', RParen for ')' and will evaluate the other terminal 85 * symbols, using either the default function or the function given in the 86 * terminal, and return the result as either True or False. 87 * 88 * All Non-Terminal functions (CondE, CondF and CondT) return Err on error. 89 */ 90 typedef enum { 91 And, Or, Not, True, False, LParen, RParen, EndOfFile, None, Err 92 } Token; 93 94 /*- 95 * Structures to handle elegantly the different forms of #if's. The 96 * last two fields are stored in condInvert and condDefProc, respectively. 97 */ 98 static int CondGetArg __P((char **, char **, char *, Boolean)); 99 static Boolean CondDoDefined __P((int, char *)); 100 static int CondStrMatch __P((char *, char *)); 101 static Boolean CondDoMake __P((int, char *)); 102 static Boolean CondDoExists __P((int, char *)); 103 static Boolean CondDoTarget __P((int, char *)); 104 static Boolean CondCvtArg __P((char *, double *)); 105 static Token CondToken __P((Boolean)); 106 static Token CondT __P((Boolean)); 107 static Token CondF __P((Boolean)); 108 static Token CondE __P((Boolean)); 109 110 static struct If { 111 char *form; /* Form of if */ 112 int formlen; /* Length of form */ 113 Boolean doNot; /* TRUE if default function should be negated */ 114 Boolean (*defProc)(); /* Default function to apply */ 115 } ifs[] = { 116 { "ifdef", 5, FALSE, CondDoDefined }, 117 { "ifndef", 6, TRUE, CondDoDefined }, 118 { "ifmake", 6, FALSE, CondDoMake }, 119 { "ifnmake", 7, TRUE, CondDoMake }, 120 { "if", 2, FALSE, CondDoDefined }, 121 { (char *)0, 0, FALSE, (Boolean (*)())0 } 122 }; 123 124 static Boolean condInvert; /* Invert the default function */ 125 static Boolean (*condDefProc)(); /* Default function to apply */ 126 static char *condExpr; /* The expression to parse */ 127 static Token condPushBack=None; /* Single push-back token used in 128 * parsing */ 129 130 #define MAXIF 30 /* greatest depth of #if'ing */ 131 132 static Boolean condStack[MAXIF]; /* Stack of conditionals's values */ 133 static int condTop = MAXIF; /* Top-most conditional */ 134 static int skipIfLevel=0; /* Depth of skipped conditionals */ 135 static Boolean skipLine = FALSE; /* Whether the parse module is skipping 136 * lines */ 137 138 /*- 139 *----------------------------------------------------------------------- 140 * CondPushBack -- 141 * Push back the most recent token read. We only need one level of 142 * this, so the thing is just stored in 'condPushback'. 143 * 144 * Results: 145 * None. 146 * 147 * Side Effects: 148 * condPushback is overwritten. 149 * 150 *----------------------------------------------------------------------- 151 */ 152 static void 153 CondPushBack (t) 154 Token t; /* Token to push back into the "stream" */ 155 { 156 condPushBack = t; 157 } 158 159 /*- 160 *----------------------------------------------------------------------- 161 * CondGetArg -- 162 * Find the argument of a built-in function. 163 * 164 * Results: 165 * The length of the argument and the address of the argument. 166 * 167 * Side Effects: 168 * The pointer is set to point to the closing parenthesis of the 169 * function call. 170 * 171 *----------------------------------------------------------------------- 172 */ 173 static int 174 CondGetArg (linePtr, argPtr, func, parens) 175 char **linePtr; 176 char **argPtr; 177 char *func; 178 Boolean parens; /* TRUE if arg should be bounded by parens */ 179 { 180 register char *cp; 181 int argLen; 182 register Buffer buf; 183 184 cp = *linePtr; 185 if (parens) { 186 while (*cp != '(' && *cp != '\0') { 187 cp++; 188 } 189 if (*cp == '(') { 190 cp++; 191 } 192 } 193 194 if (*cp == '\0') { 195 /* 196 * No arguments whatsoever. Because 'make' and 'defined' aren't really 197 * "reserved words", we don't print a message. I think this is better 198 * than hitting the user with a warning message every time s/he uses 199 * the word 'make' or 'defined' at the beginning of a symbol... 200 */ 201 *argPtr = cp; 202 return (0); 203 } 204 205 while (*cp == ' ' || *cp == '\t') { 206 cp++; 207 } 208 209 /* 210 * Create a buffer for the argument and start it out at 16 characters 211 * long. Why 16? Why not? 212 */ 213 buf = Buf_Init(16); 214 215 while ((strchr(" \t)&|", *cp) == (char *)NULL) && (*cp != '\0')) { 216 if (*cp == '$') { 217 /* 218 * Parse the variable spec and install it as part of the argument 219 * if it's valid. We tell Var_Parse to complain on an undefined 220 * variable, so we don't do it too. Nor do we return an error, 221 * though perhaps we should... 222 */ 223 char *cp2; 224 int len; 225 Boolean doFree; 226 227 cp2 = Var_Parse(cp, VAR_CMD, TRUE, &len, &doFree); 228 229 Buf_AddBytes(buf, strlen(cp2), (Byte *)cp2); 230 if (doFree) { 231 free(cp2); 232 } 233 cp += len; 234 } else { 235 Buf_AddByte(buf, (Byte)*cp); 236 cp++; 237 } 238 } 239 240 Buf_AddByte(buf, (Byte)'\0'); 241 *argPtr = (char *)Buf_GetAll(buf, &argLen); 242 Buf_Destroy(buf, FALSE); 243 244 while (*cp == ' ' || *cp == '\t') { 245 cp++; 246 } 247 if (parens && *cp != ')') { 248 Parse_Error (PARSE_WARNING, "Missing closing parenthesis for %s()", 249 func); 250 return (0); 251 } else if (parens) { 252 /* 253 * Advance pointer past close parenthesis. 254 */ 255 cp++; 256 } 257 258 *linePtr = cp; 259 return (argLen); 260 } 261 262 /*- 263 *----------------------------------------------------------------------- 264 * CondDoDefined -- 265 * Handle the 'defined' function for conditionals. 266 * 267 * Results: 268 * TRUE if the given variable is defined. 269 * 270 * Side Effects: 271 * None. 272 * 273 *----------------------------------------------------------------------- 274 */ 275 static Boolean 276 CondDoDefined (argLen, arg) 277 int argLen; 278 char *arg; 279 { 280 char savec = arg[argLen]; 281 Boolean result; 282 283 arg[argLen] = '\0'; 284 if (Var_Value (arg, VAR_CMD) != (char *)NULL) { 285 result = TRUE; 286 } else { 287 result = FALSE; 288 } 289 arg[argLen] = savec; 290 return (result); 291 } 292 293 /*- 294 *----------------------------------------------------------------------- 295 * CondStrMatch -- 296 * Front-end for Str_Match so it returns 0 on match and non-zero 297 * on mismatch. Callback function for CondDoMake via Lst_Find 298 * 299 * Results: 300 * 0 if string matches pattern 301 * 302 * Side Effects: 303 * None 304 * 305 *----------------------------------------------------------------------- 306 */ 307 static int 308 CondStrMatch(string, pattern) 309 char *string; 310 char *pattern; 311 { 312 return(!Str_Match(string,pattern)); 313 } 314 315 /*- 316 *----------------------------------------------------------------------- 317 * CondDoMake -- 318 * Handle the 'make' function for conditionals. 319 * 320 * Results: 321 * TRUE if the given target is being made. 322 * 323 * Side Effects: 324 * None. 325 * 326 *----------------------------------------------------------------------- 327 */ 328 static Boolean 329 CondDoMake (argLen, arg) 330 int argLen; 331 char *arg; 332 { 333 char savec = arg[argLen]; 334 Boolean result; 335 336 arg[argLen] = '\0'; 337 if (Lst_Find (create, (ClientData)arg, CondStrMatch) == NILLNODE) { 338 result = FALSE; 339 } else { 340 result = TRUE; 341 } 342 arg[argLen] = savec; 343 return (result); 344 } 345 346 /*- 347 *----------------------------------------------------------------------- 348 * CondDoExists -- 349 * See if the given file exists. 350 * 351 * Results: 352 * TRUE if the file exists and FALSE if it does not. 353 * 354 * Side Effects: 355 * None. 356 * 357 *----------------------------------------------------------------------- 358 */ 359 static Boolean 360 CondDoExists (argLen, arg) 361 int argLen; 362 char *arg; 363 { 364 char savec = arg[argLen]; 365 Boolean result; 366 char *path; 367 368 arg[argLen] = '\0'; 369 path = Dir_FindFile(arg, dirSearchPath); 370 if (path != (char *)NULL) { 371 result = TRUE; 372 free(path); 373 } else { 374 result = FALSE; 375 } 376 arg[argLen] = savec; 377 return (result); 378 } 379 380 /*- 381 *----------------------------------------------------------------------- 382 * CondDoTarget -- 383 * See if the given node exists and is an actual target. 384 * 385 * Results: 386 * TRUE if the node exists as a target and FALSE if it does not. 387 * 388 * Side Effects: 389 * None. 390 * 391 *----------------------------------------------------------------------- 392 */ 393 static Boolean 394 CondDoTarget (argLen, arg) 395 int argLen; 396 char *arg; 397 { 398 char savec = arg[argLen]; 399 Boolean result; 400 GNode *gn; 401 402 arg[argLen] = '\0'; 403 gn = Targ_FindNode(arg, TARG_NOCREATE); 404 if ((gn != NILGNODE) && !OP_NOP(gn->type)) { 405 result = TRUE; 406 } else { 407 result = FALSE; 408 } 409 arg[argLen] = savec; 410 return (result); 411 } 412 413 414 /*- 415 *----------------------------------------------------------------------- 416 * CondCvtArg -- 417 * Convert the given number into a double. If the number begins 418 * with 0x, it is interpreted as a hexadecimal integer 419 * and converted to a double from there. All other strings just have 420 * strtod called on them. 421 * 422 * Results: 423 * Sets 'value' to double value of string. 424 * Returns true if the string was a valid number, false o.w. 425 * 426 * Side Effects: 427 * Can change 'value' even if string is not a valid number. 428 * 429 * 430 *----------------------------------------------------------------------- 431 */ 432 static Boolean 433 CondCvtArg(str, value) 434 register char *str; 435 double *value; 436 { 437 if ((*str == '0') && (str[1] == 'x')) { 438 register long i; 439 440 for (str += 2, i = 0; *str; str++) { 441 int x; 442 if (isdigit((unsigned char) *str)) 443 x = *str - '0'; 444 else if (isxdigit((unsigned char) *str)) 445 x = 10 + *str - isupper((unsigned char) *str) ? 'A' : 'a'; 446 else 447 return FALSE; 448 i = (i << 4) + x; 449 } 450 *value = (double) i; 451 return TRUE; 452 } 453 else { 454 char *eptr; 455 *value = strtod(str, &eptr); 456 return *eptr == '\0'; 457 } 458 } 459 460 /*- 461 *----------------------------------------------------------------------- 462 * CondToken -- 463 * Return the next token from the input. 464 * 465 * Results: 466 * A Token for the next lexical token in the stream. 467 * 468 * Side Effects: 469 * condPushback will be set back to None if it is used. 470 * 471 *----------------------------------------------------------------------- 472 */ 473 static Token 474 CondToken(doEval) 475 Boolean doEval; 476 { 477 Token t; 478 479 if (condPushBack == None) { 480 while (*condExpr == ' ' || *condExpr == '\t') { 481 condExpr++; 482 } 483 switch (*condExpr) { 484 case '(': 485 t = LParen; 486 condExpr++; 487 break; 488 case ')': 489 t = RParen; 490 condExpr++; 491 break; 492 case '|': 493 if (condExpr[1] == '|') { 494 condExpr++; 495 } 496 condExpr++; 497 t = Or; 498 break; 499 case '&': 500 if (condExpr[1] == '&') { 501 condExpr++; 502 } 503 condExpr++; 504 t = And; 505 break; 506 case '!': 507 t = Not; 508 condExpr++; 509 break; 510 case '\n': 511 case '\0': 512 t = EndOfFile; 513 break; 514 case '$': { 515 char *lhs; 516 char *rhs; 517 char *op; 518 int varSpecLen; 519 Boolean doFree; 520 521 /* 522 * Parse the variable spec and skip over it, saving its 523 * value in lhs. 524 */ 525 t = Err; 526 lhs = Var_Parse(condExpr, VAR_CMD, doEval,&varSpecLen,&doFree); 527 if (lhs == var_Error) { 528 /* 529 * Even if !doEval, we still report syntax errors, which 530 * is what getting var_Error back with !doEval means. 531 */ 532 return(Err); 533 } 534 condExpr += varSpecLen; 535 536 if (!isspace(*condExpr) && strchr("!=><", *condExpr) == NULL) { 537 Buffer buf; 538 char *cp; 539 540 buf = Buf_Init(0); 541 542 for (cp = lhs; *cp; cp++) 543 Buf_AddByte(buf, (Byte)*cp); 544 545 if (doFree) 546 free(lhs); 547 548 for (;*condExpr && !isspace(*condExpr); condExpr++) 549 Buf_AddByte(buf, (Byte)*condExpr); 550 551 Buf_AddByte(buf, (Byte)'\0'); 552 lhs = (char *)Buf_GetAll(buf, &varSpecLen); 553 Buf_Destroy(buf, FALSE); 554 555 doFree = TRUE; 556 } 557 558 /* 559 * Skip whitespace to get to the operator 560 */ 561 while (isspace(*condExpr)) 562 condExpr++; 563 564 /* 565 * Make sure the operator is a valid one. If it isn't a 566 * known relational operator, pretend we got a 567 * != 0 comparison. 568 */ 569 op = condExpr; 570 switch (*condExpr) { 571 case '!': 572 case '=': 573 case '<': 574 case '>': 575 if (condExpr[1] == '=') { 576 condExpr += 2; 577 } else { 578 condExpr += 1; 579 } 580 break; 581 default: 582 op = "!="; 583 rhs = "0"; 584 585 goto do_compare; 586 } 587 while (isspace(*condExpr)) { 588 condExpr++; 589 } 590 if (*condExpr == '\0') { 591 Parse_Error(PARSE_WARNING, 592 "Missing right-hand-side of operator"); 593 goto error; 594 } 595 rhs = condExpr; 596 do_compare: 597 if (*rhs == '"') { 598 /* 599 * Doing a string comparison. Only allow == and != for 600 * operators. 601 */ 602 char *string; 603 char *cp, *cp2; 604 int qt; 605 Buffer buf; 606 607 do_string_compare: 608 if (((*op != '!') && (*op != '=')) || (op[1] != '=')) { 609 Parse_Error(PARSE_WARNING, 610 "String comparison operator should be either == or !="); 611 goto error; 612 } 613 614 buf = Buf_Init(0); 615 qt = *rhs == '"' ? 1 : 0; 616 617 for (cp = &rhs[qt]; 618 ((qt && (*cp != '"')) || 619 (!qt && strchr(" \t)", *cp) == NULL)) && 620 (*cp != '\0'); cp++) { 621 if ((*cp == '\\') && (cp[1] != '\0')) { 622 /* 623 * Backslash escapes things -- skip over next 624 * character, if it exists. 625 */ 626 cp++; 627 Buf_AddByte(buf, (Byte)*cp); 628 } else if (*cp == '$') { 629 int len; 630 Boolean freeIt; 631 632 cp2 = Var_Parse(cp, VAR_CMD, doEval,&len, &freeIt); 633 if (cp2 != var_Error) { 634 Buf_AddBytes(buf, strlen(cp2), (Byte *)cp2); 635 if (freeIt) { 636 free(cp2); 637 } 638 cp += len - 1; 639 } else { 640 Buf_AddByte(buf, (Byte)*cp); 641 } 642 } else { 643 Buf_AddByte(buf, (Byte)*cp); 644 } 645 } 646 647 Buf_AddByte(buf, (Byte)0); 648 649 string = (char *)Buf_GetAll(buf, (int *)0); 650 Buf_Destroy(buf, FALSE); 651 652 if (DEBUG(COND)) { 653 printf("lhs = \"%s\", rhs = \"%s\", op = %.2s\n", 654 lhs, string, op); 655 } 656 /* 657 * Null-terminate rhs and perform the comparison. 658 * t is set to the result. 659 */ 660 if (*op == '=') { 661 t = strcmp(lhs, string) ? False : True; 662 } else { 663 t = strcmp(lhs, string) ? True : False; 664 } 665 free(string); 666 if (rhs == condExpr) { 667 if (!qt && *cp == ')') 668 condExpr = cp; 669 else 670 condExpr = cp + 1; 671 } 672 } else { 673 /* 674 * rhs is either a float or an integer. Convert both the 675 * lhs and the rhs to a double and compare the two. 676 */ 677 double left, right; 678 char *string; 679 680 if (!CondCvtArg(lhs, &left)) 681 goto do_string_compare; 682 if (*rhs == '$') { 683 int len; 684 Boolean freeIt; 685 686 string = Var_Parse(rhs, VAR_CMD, doEval,&len,&freeIt); 687 if (string == var_Error) { 688 right = 0.0; 689 } else { 690 if (!CondCvtArg(string, &right)) { 691 if (freeIt) 692 free(string); 693 goto do_string_compare; 694 } 695 if (freeIt) 696 free(string); 697 if (rhs == condExpr) 698 condExpr += len; 699 } 700 } else { 701 if (!CondCvtArg(rhs, &right)) 702 goto do_string_compare; 703 if (rhs == condExpr) { 704 /* 705 * Skip over the right-hand side 706 */ 707 while(!isspace(*condExpr) && (*condExpr != '\0')) { 708 condExpr++; 709 } 710 } 711 } 712 713 if (DEBUG(COND)) { 714 printf("left = %f, right = %f, op = %.2s\n", left, 715 right, op); 716 } 717 switch(op[0]) { 718 case '!': 719 if (op[1] != '=') { 720 Parse_Error(PARSE_WARNING, 721 "Unknown operator"); 722 goto error; 723 } 724 t = (left != right ? True : False); 725 break; 726 case '=': 727 if (op[1] != '=') { 728 Parse_Error(PARSE_WARNING, 729 "Unknown operator"); 730 goto error; 731 } 732 t = (left == right ? True : False); 733 break; 734 case '<': 735 if (op[1] == '=') { 736 t = (left <= right ? True : False); 737 } else { 738 t = (left < right ? True : False); 739 } 740 break; 741 case '>': 742 if (op[1] == '=') { 743 t = (left >= right ? True : False); 744 } else { 745 t = (left > right ? True : False); 746 } 747 break; 748 } 749 } 750 error: 751 if (doFree) 752 free(lhs); 753 break; 754 } 755 default: { 756 Boolean (*evalProc)(); 757 Boolean invert = FALSE; 758 char *arg; 759 int arglen; 760 761 if (strncmp (condExpr, "defined", 7) == 0) { 762 /* 763 * Use CondDoDefined to evaluate the argument and 764 * CondGetArg to extract the argument from the 'function 765 * call'. 766 */ 767 evalProc = CondDoDefined; 768 condExpr += 7; 769 arglen = CondGetArg (&condExpr, &arg, "defined", TRUE); 770 if (arglen == 0) { 771 condExpr -= 7; 772 goto use_default; 773 } 774 } else if (strncmp (condExpr, "make", 4) == 0) { 775 /* 776 * Use CondDoMake to evaluate the argument and 777 * CondGetArg to extract the argument from the 'function 778 * call'. 779 */ 780 evalProc = CondDoMake; 781 condExpr += 4; 782 arglen = CondGetArg (&condExpr, &arg, "make", TRUE); 783 if (arglen == 0) { 784 condExpr -= 4; 785 goto use_default; 786 } 787 } else if (strncmp (condExpr, "exists", 6) == 0) { 788 /* 789 * Use CondDoExists to evaluate the argument and 790 * CondGetArg to extract the argument from the 791 * 'function call'. 792 */ 793 evalProc = CondDoExists; 794 condExpr += 6; 795 arglen = CondGetArg(&condExpr, &arg, "exists", TRUE); 796 if (arglen == 0) { 797 condExpr -= 6; 798 goto use_default; 799 } 800 } else if (strncmp(condExpr, "empty", 5) == 0) { 801 /* 802 * Use Var_Parse to parse the spec in parens and return 803 * True if the resulting string is empty. 804 */ 805 int length; 806 Boolean doFree; 807 char *val; 808 809 condExpr += 5; 810 811 for (arglen = 0; 812 condExpr[arglen] != '(' && condExpr[arglen] != '\0'; 813 arglen += 1) 814 { 815 /* void */ ; 816 } 817 if (condExpr[arglen] != '\0') { 818 val = Var_Parse(&condExpr[arglen - 1], VAR_CMD, 819 doEval, &length, &doFree); 820 if (val == var_Error) { 821 t = Err; 822 } else { 823 /* 824 * A variable is empty when it just contains 825 * spaces... 4/15/92, christos 826 */ 827 char *p; 828 for (p = val; *p && isspace(*p); p++) 829 continue; 830 t = (*p == '\0') ? True : False; 831 } 832 if (doFree) { 833 free(val); 834 } 835 /* 836 * Advance condExpr to beyond the closing ). Note that 837 * we subtract one from arglen + length b/c length 838 * is calculated from condExpr[arglen - 1]. 839 */ 840 condExpr += arglen + length - 1; 841 } else { 842 condExpr -= 5; 843 goto use_default; 844 } 845 break; 846 } else if (strncmp (condExpr, "target", 6) == 0) { 847 /* 848 * Use CondDoTarget to evaluate the argument and 849 * CondGetArg to extract the argument from the 850 * 'function call'. 851 */ 852 evalProc = CondDoTarget; 853 condExpr += 6; 854 arglen = CondGetArg(&condExpr, &arg, "target", TRUE); 855 if (arglen == 0) { 856 condExpr -= 6; 857 goto use_default; 858 } 859 } else { 860 /* 861 * The symbol is itself the argument to the default 862 * function. We advance condExpr to the end of the symbol 863 * by hand (the next whitespace, closing paren or 864 * binary operator) and set to invert the evaluation 865 * function if condInvert is TRUE. 866 */ 867 use_default: 868 invert = condInvert; 869 evalProc = condDefProc; 870 arglen = CondGetArg(&condExpr, &arg, "", FALSE); 871 } 872 873 /* 874 * Evaluate the argument using the set function. If invert 875 * is TRUE, we invert the sense of the function. 876 */ 877 t = (!doEval || (* evalProc) (arglen, arg) ? 878 (invert ? False : True) : 879 (invert ? True : False)); 880 free(arg); 881 break; 882 } 883 } 884 } else { 885 t = condPushBack; 886 condPushBack = None; 887 } 888 return (t); 889 } 890 891 /*- 892 *----------------------------------------------------------------------- 893 * CondT -- 894 * Parse a single term in the expression. This consists of a terminal 895 * symbol or Not and a terminal symbol (not including the binary 896 * operators): 897 * T -> defined(variable) | make(target) | exists(file) | symbol 898 * T -> ! T | ( E ) 899 * 900 * Results: 901 * True, False or Err. 902 * 903 * Side Effects: 904 * Tokens are consumed. 905 * 906 *----------------------------------------------------------------------- 907 */ 908 static Token 909 CondT(doEval) 910 Boolean doEval; 911 { 912 Token t; 913 914 t = CondToken(doEval); 915 916 if (t == EndOfFile) { 917 /* 918 * If we reached the end of the expression, the expression 919 * is malformed... 920 */ 921 t = Err; 922 } else if (t == LParen) { 923 /* 924 * T -> ( E ) 925 */ 926 t = CondE(doEval); 927 if (t != Err) { 928 if (CondToken(doEval) != RParen) { 929 t = Err; 930 } 931 } 932 } else if (t == Not) { 933 t = CondT(doEval); 934 if (t == True) { 935 t = False; 936 } else if (t == False) { 937 t = True; 938 } 939 } 940 return (t); 941 } 942 943 /*- 944 *----------------------------------------------------------------------- 945 * CondF -- 946 * Parse a conjunctive factor (nice name, wot?) 947 * F -> T && F | T 948 * 949 * Results: 950 * True, False or Err 951 * 952 * Side Effects: 953 * Tokens are consumed. 954 * 955 *----------------------------------------------------------------------- 956 */ 957 static Token 958 CondF(doEval) 959 Boolean doEval; 960 { 961 Token l, o; 962 963 l = CondT(doEval); 964 if (l != Err) { 965 o = CondToken(doEval); 966 967 if (o == And) { 968 /* 969 * F -> T && F 970 * 971 * If T is False, the whole thing will be False, but we have to 972 * parse the r.h.s. anyway (to throw it away). 973 * If T is True, the result is the r.h.s., be it an Err or no. 974 */ 975 if (l == True) { 976 l = CondF(doEval); 977 } else { 978 (void) CondF(FALSE); 979 } 980 } else { 981 /* 982 * F -> T 983 */ 984 CondPushBack (o); 985 } 986 } 987 return (l); 988 } 989 990 /*- 991 *----------------------------------------------------------------------- 992 * CondE -- 993 * Main expression production. 994 * E -> F || E | F 995 * 996 * Results: 997 * True, False or Err. 998 * 999 * Side Effects: 1000 * Tokens are, of course, consumed. 1001 * 1002 *----------------------------------------------------------------------- 1003 */ 1004 static Token 1005 CondE(doEval) 1006 Boolean doEval; 1007 { 1008 Token l, o; 1009 1010 l = CondF(doEval); 1011 if (l != Err) { 1012 o = CondToken(doEval); 1013 1014 if (o == Or) { 1015 /* 1016 * E -> F || E 1017 * 1018 * A similar thing occurs for ||, except that here we make sure 1019 * the l.h.s. is False before we bother to evaluate the r.h.s. 1020 * Once again, if l is False, the result is the r.h.s. and once 1021 * again if l is True, we parse the r.h.s. to throw it away. 1022 */ 1023 if (l == False) { 1024 l = CondE(doEval); 1025 } else { 1026 (void) CondE(FALSE); 1027 } 1028 } else { 1029 /* 1030 * E -> F 1031 */ 1032 CondPushBack (o); 1033 } 1034 } 1035 return (l); 1036 } 1037 1038 /*- 1039 *----------------------------------------------------------------------- 1040 * Cond_Eval -- 1041 * Evaluate the conditional in the passed line. The line 1042 * looks like this: 1043 * #<cond-type> <expr> 1044 * where <cond-type> is any of if, ifmake, ifnmake, ifdef, 1045 * ifndef, elif, elifmake, elifnmake, elifdef, elifndef 1046 * and <expr> consists of &&, ||, !, make(target), defined(variable) 1047 * and parenthetical groupings thereof. 1048 * 1049 * Results: 1050 * COND_PARSE if should parse lines after the conditional 1051 * COND_SKIP if should skip lines after the conditional 1052 * COND_INVALID if not a valid conditional. 1053 * 1054 * Side Effects: 1055 * None. 1056 * 1057 *----------------------------------------------------------------------- 1058 */ 1059 int 1060 Cond_Eval (line) 1061 char *line; /* Line to parse */ 1062 { 1063 struct If *ifp; 1064 Boolean isElse; 1065 Boolean value = FALSE; 1066 int level; /* Level at which to report errors. */ 1067 1068 level = PARSE_FATAL; 1069 1070 for (line++; *line == ' ' || *line == '\t'; line++) { 1071 continue; 1072 } 1073 1074 /* 1075 * Find what type of if we're dealing with. The result is left 1076 * in ifp and isElse is set TRUE if it's an elif line. 1077 */ 1078 if (line[0] == 'e' && line[1] == 'l') { 1079 line += 2; 1080 isElse = TRUE; 1081 } else if (strncmp (line, "endif", 5) == 0) { 1082 /* 1083 * End of a conditional section. If skipIfLevel is non-zero, that 1084 * conditional was skipped, so lines following it should also be 1085 * skipped. Hence, we return COND_SKIP. Otherwise, the conditional 1086 * was read so succeeding lines should be parsed (think about it...) 1087 * so we return COND_PARSE, unless this endif isn't paired with 1088 * a decent if. 1089 */ 1090 if (skipIfLevel != 0) { 1091 skipIfLevel -= 1; 1092 return (COND_SKIP); 1093 } else { 1094 if (condTop == MAXIF) { 1095 Parse_Error (level, "if-less endif"); 1096 return (COND_INVALID); 1097 } else { 1098 skipLine = FALSE; 1099 condTop += 1; 1100 return (COND_PARSE); 1101 } 1102 } 1103 } else { 1104 isElse = FALSE; 1105 } 1106 1107 /* 1108 * Figure out what sort of conditional it is -- what its default 1109 * function is, etc. -- by looking in the table of valid "ifs" 1110 */ 1111 for (ifp = ifs; ifp->form != (char *)0; ifp++) { 1112 if (strncmp (ifp->form, line, ifp->formlen) == 0) { 1113 break; 1114 } 1115 } 1116 1117 if (ifp->form == (char *) 0) { 1118 /* 1119 * Nothing fit. If the first word on the line is actually 1120 * "else", it's a valid conditional whose value is the inverse 1121 * of the previous if we parsed. 1122 */ 1123 if (isElse && (line[0] == 's') && (line[1] == 'e')) { 1124 if (condTop == MAXIF) { 1125 Parse_Error (level, "if-less else"); 1126 return (COND_INVALID); 1127 } else if (skipIfLevel == 0) { 1128 value = !condStack[condTop]; 1129 } else { 1130 return (COND_SKIP); 1131 } 1132 } else { 1133 /* 1134 * Not a valid conditional type. No error... 1135 */ 1136 return (COND_INVALID); 1137 } 1138 } else { 1139 if (isElse) { 1140 if (condTop == MAXIF) { 1141 Parse_Error (level, "if-less elif"); 1142 return (COND_INVALID); 1143 } else if (skipIfLevel != 0) { 1144 /* 1145 * If skipping this conditional, just ignore the whole thing. 1146 * If we don't, the user might be employing a variable that's 1147 * undefined, for which there's an enclosing ifdef that 1148 * we're skipping... 1149 */ 1150 return(COND_SKIP); 1151 } 1152 } else if (skipLine) { 1153 /* 1154 * Don't even try to evaluate a conditional that's not an else if 1155 * we're skipping things... 1156 */ 1157 skipIfLevel += 1; 1158 return(COND_SKIP); 1159 } 1160 1161 /* 1162 * Initialize file-global variables for parsing 1163 */ 1164 condDefProc = ifp->defProc; 1165 condInvert = ifp->doNot; 1166 1167 line += ifp->formlen; 1168 1169 while (*line == ' ' || *line == '\t') { 1170 line++; 1171 } 1172 1173 condExpr = line; 1174 condPushBack = None; 1175 1176 switch (CondE(TRUE)) { 1177 case True: 1178 if (CondToken(TRUE) == EndOfFile) { 1179 value = TRUE; 1180 break; 1181 } 1182 goto err; 1183 /*FALLTHRU*/ 1184 case False: 1185 if (CondToken(TRUE) == EndOfFile) { 1186 value = FALSE; 1187 break; 1188 } 1189 /*FALLTHRU*/ 1190 case Err: 1191 err: 1192 Parse_Error (level, "Malformed conditional (%s)", 1193 line); 1194 return (COND_INVALID); 1195 default: 1196 break; 1197 } 1198 } 1199 if (!isElse) { 1200 condTop -= 1; 1201 } else if ((skipIfLevel != 0) || condStack[condTop]) { 1202 /* 1203 * If this is an else-type conditional, it should only take effect 1204 * if its corresponding if was evaluated and FALSE. If its if was 1205 * TRUE or skipped, we return COND_SKIP (and start skipping in case 1206 * we weren't already), leaving the stack unmolested so later elif's 1207 * don't screw up... 1208 */ 1209 skipLine = TRUE; 1210 return (COND_SKIP); 1211 } 1212 1213 if (condTop < 0) { 1214 /* 1215 * This is the one case where we can definitely proclaim a fatal 1216 * error. If we don't, we're hosed. 1217 */ 1218 Parse_Error (PARSE_FATAL, "Too many nested if's. %d max.", MAXIF); 1219 return (COND_INVALID); 1220 } else { 1221 condStack[condTop] = value; 1222 skipLine = !value; 1223 return (value ? COND_PARSE : COND_SKIP); 1224 } 1225 } 1226 1227 /*- 1228 *----------------------------------------------------------------------- 1229 * Cond_End -- 1230 * Make sure everything's clean at the end of a makefile. 1231 * 1232 * Results: 1233 * None. 1234 * 1235 * Side Effects: 1236 * Parse_Error will be called if open conditionals are around. 1237 * 1238 *----------------------------------------------------------------------- 1239 */ 1240 void 1241 Cond_End() 1242 { 1243 if (condTop != MAXIF) { 1244 Parse_Error(PARSE_FATAL, "%d open conditional%s", MAXIF-condTop, 1245 MAXIF-condTop == 1 ? "" : "s"); 1246 } 1247 condTop = MAXIF; 1248 } 1249