cond.c revision 18804
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 * $Id$ 39 */ 40 41#ifndef lint 42static char sccsid[] = "@(#)cond.c 8.2 (Berkeley) 1/2/94"; 43#endif /* not lint */ 44 45/*- 46 * cond.c -- 47 * Functions to handle conditionals in a makefile. 48 * 49 * Interface: 50 * Cond_Eval Evaluate the conditional in the passed line. 51 * 52 */ 53 54#include <ctype.h> 55#include <math.h> 56#include "make.h" 57#include "hash.h" 58#include "dir.h" 59#include "buf.h" 60 61/* 62 * The parsing of conditional expressions is based on this grammar: 63 * E -> F || E 64 * E -> F 65 * F -> T && F 66 * F -> T 67 * T -> defined(variable) 68 * T -> make(target) 69 * T -> exists(file) 70 * T -> empty(varspec) 71 * T -> target(name) 72 * T -> symbol 73 * T -> $(varspec) op value 74 * T -> $(varspec) == "string" 75 * T -> $(varspec) != "string" 76 * T -> ( E ) 77 * T -> ! T 78 * op -> == | != | > | < | >= | <= 79 * 80 * 'symbol' is some other symbol to which the default function (condDefProc) 81 * is applied. 82 * 83 * Tokens are scanned from the 'condExpr' string. The scanner (CondToken) 84 * will return And for '&' and '&&', Or for '|' and '||', Not for '!', 85 * LParen for '(', RParen for ')' and will evaluate the other terminal 86 * symbols, using either the default function or the function given in the 87 * terminal, and return the result as either True or False. 88 * 89 * All Non-Terminal functions (CondE, CondF and CondT) return Err on error. 90 */ 91typedef enum { 92 And, Or, Not, True, False, LParen, RParen, EndOfFile, None, Err 93} Token; 94 95/*- 96 * Structures to handle elegantly the different forms of #if's. The 97 * last two fields are stored in condInvert and condDefProc, respectively. 98 */ 99static void CondPushBack __P((Token)); 100static int CondGetArg __P((char **, char **, char *, Boolean)); 101static Boolean CondDoDefined __P((int, char *)); 102static int CondStrMatch __P((ClientData, ClientData)); 103static Boolean CondDoMake __P((int, char *)); 104static Boolean CondDoExists __P((int, char *)); 105static Boolean CondDoTarget __P((int, char *)); 106static Boolean CondCvtArg __P((char *, double *)); 107static Token CondToken __P((Boolean)); 108static Token CondT __P((Boolean)); 109static Token CondF __P((Boolean)); 110static Token CondE __P((Boolean)); 111 112static struct If { 113 char *form; /* Form of if */ 114 int formlen; /* Length of form */ 115 Boolean doNot; /* TRUE if default function should be negated */ 116 Boolean (*defProc) __P((int, char *)); /* Default function to apply */ 117} ifs[] = { 118 { "ifdef", 5, FALSE, CondDoDefined }, 119 { "ifndef", 6, TRUE, CondDoDefined }, 120 { "ifmake", 6, FALSE, CondDoMake }, 121 { "ifnmake", 7, TRUE, CondDoMake }, 122 { "if", 2, FALSE, CondDoDefined }, 123 { NULL, 0, FALSE, NULL } 124}; 125 126static Boolean condInvert; /* Invert the default function */ 127static Boolean (*condDefProc) /* Default function to apply */ 128 __P((int, char *)); 129static char *condExpr; /* The expression to parse */ 130static Token condPushBack=None; /* Single push-back token used in 131 * parsing */ 132 133#define MAXIF 30 /* greatest depth of #if'ing */ 134 135static Boolean condStack[MAXIF]; /* Stack of conditionals's values */ 136static int condTop = MAXIF; /* Top-most conditional */ 137static int skipIfLevel=0; /* Depth of skipped conditionals */ 138static Boolean skipLine = FALSE; /* Whether the parse module is skipping 139 * lines */ 140 141/*- 142 *----------------------------------------------------------------------- 143 * CondPushBack -- 144 * Push back the most recent token read. We only need one level of 145 * this, so the thing is just stored in 'condPushback'. 146 * 147 * Results: 148 * None. 149 * 150 * Side Effects: 151 * condPushback is overwritten. 152 * 153 *----------------------------------------------------------------------- 154 */ 155static void 156CondPushBack (t) 157 Token t; /* Token to push back into the "stream" */ 158{ 159 condPushBack = t; 160} 161 162/*- 163 *----------------------------------------------------------------------- 164 * CondGetArg -- 165 * Find the argument of a built-in function. 166 * 167 * Results: 168 * The length of the argument and the address of the argument. 169 * 170 * Side Effects: 171 * The pointer is set to point to the closing parenthesis of the 172 * function call. 173 * 174 *----------------------------------------------------------------------- 175 */ 176static int 177CondGetArg (linePtr, argPtr, func, parens) 178 char **linePtr; 179 char **argPtr; 180 char *func; 181 Boolean parens; /* TRUE if arg should be bounded by parens */ 182{ 183 register char *cp; 184 int argLen; 185 register Buffer buf; 186 187 cp = *linePtr; 188 if (parens) { 189 while (*cp != '(' && *cp != '\0') { 190 cp++; 191 } 192 if (*cp == '(') { 193 cp++; 194 } 195 } 196 197 if (*cp == '\0') { 198 /* 199 * No arguments whatsoever. Because 'make' and 'defined' aren't really 200 * "reserved words", we don't print a message. I think this is better 201 * than hitting the user with a warning message every time s/he uses 202 * the word 'make' or 'defined' at the beginning of a symbol... 203 */ 204 *argPtr = cp; 205 return (0); 206 } 207 208 while (*cp == ' ' || *cp == '\t') { 209 cp++; 210 } 211 212 /* 213 * Create a buffer for the argument and start it out at 16 characters 214 * long. Why 16? Why not? 215 */ 216 buf = Buf_Init(16); 217 218 while ((strchr(" \t)&|", *cp) == (char *)NULL) && (*cp != '\0')) { 219 if (*cp == '$') { 220 /* 221 * Parse the variable spec and install it as part of the argument 222 * if it's valid. We tell Var_Parse to complain on an undefined 223 * variable, so we don't do it too. Nor do we return an error, 224 * though perhaps we should... 225 */ 226 char *cp2; 227 int len; 228 Boolean doFree; 229 230 cp2 = Var_Parse(cp, VAR_CMD, TRUE, &len, &doFree); 231 232 Buf_AddBytes(buf, strlen(cp2), (Byte *)cp2); 233 if (doFree) { 234 free(cp2); 235 } 236 cp += len; 237 } else { 238 Buf_AddByte(buf, (Byte)*cp); 239 cp++; 240 } 241 } 242 243 Buf_AddByte(buf, (Byte)'\0'); 244 *argPtr = (char *)Buf_GetAll(buf, &argLen); 245 Buf_Destroy(buf, FALSE); 246 247 while (*cp == ' ' || *cp == '\t') { 248 cp++; 249 } 250 if (parens && *cp != ')') { 251 Parse_Error (PARSE_WARNING, "Missing closing parenthesis for %s()", 252 func); 253 return (0); 254 } else if (parens) { 255 /* 256 * Advance pointer past close parenthesis. 257 */ 258 cp++; 259 } 260 261 *linePtr = cp; 262 return (argLen); 263} 264 265/*- 266 *----------------------------------------------------------------------- 267 * CondDoDefined -- 268 * Handle the 'defined' function for conditionals. 269 * 270 * Results: 271 * TRUE if the given variable is defined. 272 * 273 * Side Effects: 274 * None. 275 * 276 *----------------------------------------------------------------------- 277 */ 278static Boolean 279CondDoDefined (argLen, arg) 280 int argLen; 281 char *arg; 282{ 283 char savec = arg[argLen]; 284 char *p1; 285 Boolean result; 286 287 arg[argLen] = '\0'; 288 if (Var_Value (arg, VAR_CMD, &p1) != (char *)NULL) { 289 result = TRUE; 290 } else { 291 result = FALSE; 292 } 293 if (p1) 294 free(p1); 295 arg[argLen] = savec; 296 return (result); 297} 298 299/*- 300 *----------------------------------------------------------------------- 301 * CondStrMatch -- 302 * Front-end for Str_Match so it returns 0 on match and non-zero 303 * on mismatch. Callback function for CondDoMake via Lst_Find 304 * 305 * Results: 306 * 0 if string matches pattern 307 * 308 * Side Effects: 309 * None 310 * 311 *----------------------------------------------------------------------- 312 */ 313static int 314CondStrMatch(string, pattern) 315 ClientData string; 316 ClientData pattern; 317{ 318 return(!Str_Match((char *) string,(char *) pattern)); 319} 320 321/*- 322 *----------------------------------------------------------------------- 323 * CondDoMake -- 324 * Handle the 'make' function for conditionals. 325 * 326 * Results: 327 * TRUE if the given target is being made. 328 * 329 * Side Effects: 330 * None. 331 * 332 *----------------------------------------------------------------------- 333 */ 334static Boolean 335CondDoMake (argLen, arg) 336 int argLen; 337 char *arg; 338{ 339 char savec = arg[argLen]; 340 Boolean result; 341 342 arg[argLen] = '\0'; 343 if (Lst_Find (create, (ClientData)arg, CondStrMatch) == NILLNODE) { 344 result = FALSE; 345 } else { 346 result = TRUE; 347 } 348 arg[argLen] = savec; 349 return (result); 350} 351 352/*- 353 *----------------------------------------------------------------------- 354 * CondDoExists -- 355 * See if the given file exists. 356 * 357 * Results: 358 * TRUE if the file exists and FALSE if it does not. 359 * 360 * Side Effects: 361 * None. 362 * 363 *----------------------------------------------------------------------- 364 */ 365static Boolean 366CondDoExists (argLen, arg) 367 int argLen; 368 char *arg; 369{ 370 char savec = arg[argLen]; 371 Boolean result; 372 char *path; 373 374 arg[argLen] = '\0'; 375 path = Dir_FindFile(arg, dirSearchPath); 376 if (path != (char *)NULL) { 377 result = TRUE; 378 free(path); 379 } else { 380 result = FALSE; 381 } 382 arg[argLen] = savec; 383 return (result); 384} 385 386/*- 387 *----------------------------------------------------------------------- 388 * CondDoTarget -- 389 * See if the given node exists and is an actual target. 390 * 391 * Results: 392 * TRUE if the node exists as a target and FALSE if it does not. 393 * 394 * Side Effects: 395 * None. 396 * 397 *----------------------------------------------------------------------- 398 */ 399static Boolean 400CondDoTarget (argLen, arg) 401 int argLen; 402 char *arg; 403{ 404 char savec = arg[argLen]; 405 Boolean result; 406 GNode *gn; 407 408 arg[argLen] = '\0'; 409 gn = Targ_FindNode(arg, TARG_NOCREATE); 410 if ((gn != NILGNODE) && !OP_NOP(gn->type)) { 411 result = TRUE; 412 } else { 413 result = FALSE; 414 } 415 arg[argLen] = savec; 416 return (result); 417} 418 419 420/*- 421 *----------------------------------------------------------------------- 422 * CondCvtArg -- 423 * Convert the given number into a double. If the number begins 424 * with 0x, it is interpreted as a hexadecimal integer 425 * and converted to a double from there. All other strings just have 426 * strtod called on them. 427 * 428 * Results: 429 * Sets 'value' to double value of string. 430 * Returns true if the string was a valid number, false o.w. 431 * 432 * Side Effects: 433 * Can change 'value' even if string is not a valid number. 434 * 435 * 436 *----------------------------------------------------------------------- 437 */ 438static Boolean 439CondCvtArg(str, value) 440 register char *str; 441 double *value; 442{ 443 if ((*str == '0') && (str[1] == 'x')) { 444 register long i; 445 446 for (str += 2, i = 0; *str; str++) { 447 int x; 448 if (isdigit((unsigned char) *str)) 449 x = *str - '0'; 450 else if (isxdigit((unsigned char) *str)) 451 x = 10 + *str - isupper((unsigned char) *str) ? 'A' : 'a'; 452 else 453 return FALSE; 454 i = (i << 4) + x; 455 } 456 *value = (double) i; 457 return TRUE; 458 } 459 else { 460 char *eptr; 461 *value = strtod(str, &eptr); 462 return *eptr == '\0'; 463 } 464} 465 466/*- 467 *----------------------------------------------------------------------- 468 * CondToken -- 469 * Return the next token from the input. 470 * 471 * Results: 472 * A Token for the next lexical token in the stream. 473 * 474 * Side Effects: 475 * condPushback will be set back to None if it is used. 476 * 477 *----------------------------------------------------------------------- 478 */ 479static Token 480CondToken(doEval) 481 Boolean doEval; 482{ 483 Token t; 484 485 if (condPushBack == None) { 486 while (*condExpr == ' ' || *condExpr == '\t') { 487 condExpr++; 488 } 489 switch (*condExpr) { 490 case '(': 491 t = LParen; 492 condExpr++; 493 break; 494 case ')': 495 t = RParen; 496 condExpr++; 497 break; 498 case '|': 499 if (condExpr[1] == '|') { 500 condExpr++; 501 } 502 condExpr++; 503 t = Or; 504 break; 505 case '&': 506 if (condExpr[1] == '&') { 507 condExpr++; 508 } 509 condExpr++; 510 t = And; 511 break; 512 case '!': 513 t = Not; 514 condExpr++; 515 break; 516 case '\n': 517 case '\0': 518 t = EndOfFile; 519 break; 520 case '$': { 521 char *lhs; 522 char *rhs; 523 char *op; 524 int varSpecLen; 525 Boolean doFree; 526 527 /* 528 * Parse the variable spec and skip over it, saving its 529 * value in lhs. 530 */ 531 t = Err; 532 lhs = Var_Parse(condExpr, VAR_CMD, doEval,&varSpecLen,&doFree); 533 if (lhs == var_Error) { 534 /* 535 * Even if !doEval, we still report syntax errors, which 536 * is what getting var_Error back with !doEval means. 537 */ 538 return(Err); 539 } 540 condExpr += varSpecLen; 541 542 if (!isspace((unsigned char) *condExpr) && 543 strchr("!=><", *condExpr) == NULL) { 544 Buffer buf; 545 char *cp; 546 547 buf = Buf_Init(0); 548 549 for (cp = lhs; *cp; cp++) 550 Buf_AddByte(buf, (Byte)*cp); 551 552 if (doFree) 553 free(lhs); 554 555 for (;*condExpr && !isspace((unsigned char) *condExpr); 556 condExpr++) 557 Buf_AddByte(buf, (Byte)*condExpr); 558 559 Buf_AddByte(buf, (Byte)'\0'); 560 lhs = (char *)Buf_GetAll(buf, &varSpecLen); 561 Buf_Destroy(buf, FALSE); 562 563 doFree = TRUE; 564 } 565 566 /* 567 * Skip whitespace to get to the operator 568 */ 569 while (isspace((unsigned char) *condExpr)) 570 condExpr++; 571 572 /* 573 * Make sure the operator is a valid one. If it isn't a 574 * known relational operator, pretend we got a 575 * != 0 comparison. 576 */ 577 op = condExpr; 578 switch (*condExpr) { 579 case '!': 580 case '=': 581 case '<': 582 case '>': 583 if (condExpr[1] == '=') { 584 condExpr += 2; 585 } else { 586 condExpr += 1; 587 } 588 break; 589 default: 590 op = "!="; 591 rhs = "0"; 592 593 goto do_compare; 594 } 595 while (isspace((unsigned char) *condExpr)) { 596 condExpr++; 597 } 598 if (*condExpr == '\0') { 599 Parse_Error(PARSE_WARNING, 600 "Missing right-hand-side of operator"); 601 goto error; 602 } 603 rhs = condExpr; 604do_compare: 605 if (*rhs == '"') { 606 /* 607 * Doing a string comparison. Only allow == and != for 608 * operators. 609 */ 610 char *string; 611 char *cp, *cp2; 612 int qt; 613 Buffer buf; 614 615do_string_compare: 616 if (((*op != '!') && (*op != '=')) || (op[1] != '=')) { 617 Parse_Error(PARSE_WARNING, 618 "String comparison operator should be either == or !="); 619 goto error; 620 } 621 622 buf = Buf_Init(0); 623 qt = *rhs == '"' ? 1 : 0; 624 625 for (cp = &rhs[qt]; 626 ((qt && (*cp != '"')) || 627 (!qt && strchr(" \t)", *cp) == NULL)) && 628 (*cp != '\0'); cp++) { 629 if ((*cp == '\\') && (cp[1] != '\0')) { 630 /* 631 * Backslash escapes things -- skip over next 632 * character, if it exists. 633 */ 634 cp++; 635 Buf_AddByte(buf, (Byte)*cp); 636 } else if (*cp == '$') { 637 int len; 638 Boolean freeIt; 639 640 cp2 = Var_Parse(cp, VAR_CMD, doEval,&len, &freeIt); 641 if (cp2 != var_Error) { 642 Buf_AddBytes(buf, strlen(cp2), (Byte *)cp2); 643 if (freeIt) { 644 free(cp2); 645 } 646 cp += len - 1; 647 } else { 648 Buf_AddByte(buf, (Byte)*cp); 649 } 650 } else { 651 Buf_AddByte(buf, (Byte)*cp); 652 } 653 } 654 655 Buf_AddByte(buf, (Byte)0); 656 657 string = (char *)Buf_GetAll(buf, (int *)0); 658 Buf_Destroy(buf, FALSE); 659 660 if (DEBUG(COND)) { 661 printf("lhs = \"%s\", rhs = \"%s\", op = %.2s\n", 662 lhs, string, op); 663 } 664 /* 665 * Null-terminate rhs and perform the comparison. 666 * t is set to the result. 667 */ 668 if (*op == '=') { 669 t = strcmp(lhs, string) ? False : True; 670 } else { 671 t = strcmp(lhs, string) ? True : False; 672 } 673 free(string); 674 if (rhs == condExpr) { 675 if (!qt && *cp == ')') 676 condExpr = cp; 677 else 678 condExpr = cp + 1; 679 } 680 } else { 681 /* 682 * rhs is either a float or an integer. Convert both the 683 * lhs and the rhs to a double and compare the two. 684 */ 685 double left, right; 686 char *string; 687 688 if (!CondCvtArg(lhs, &left)) 689 goto do_string_compare; 690 if (*rhs == '$') { 691 int len; 692 Boolean freeIt; 693 694 string = Var_Parse(rhs, VAR_CMD, doEval,&len,&freeIt); 695 if (string == var_Error) { 696 right = 0.0; 697 } else { 698 if (!CondCvtArg(string, &right)) { 699 if (freeIt) 700 free(string); 701 goto do_string_compare; 702 } 703 if (freeIt) 704 free(string); 705 if (rhs == condExpr) 706 condExpr += len; 707 } 708 } else { 709 if (!CondCvtArg(rhs, &right)) 710 goto do_string_compare; 711 if (rhs == condExpr) { 712 /* 713 * Skip over the right-hand side 714 */ 715 while(!isspace((unsigned char) *condExpr) && 716 (*condExpr != '\0')) { 717 condExpr++; 718 } 719 } 720 } 721 722 if (DEBUG(COND)) { 723 printf("left = %f, right = %f, op = %.2s\n", left, 724 right, op); 725 } 726 switch(op[0]) { 727 case '!': 728 if (op[1] != '=') { 729 Parse_Error(PARSE_WARNING, 730 "Unknown operator"); 731 goto error; 732 } 733 t = (left != right ? True : False); 734 break; 735 case '=': 736 if (op[1] != '=') { 737 Parse_Error(PARSE_WARNING, 738 "Unknown operator"); 739 goto error; 740 } 741 t = (left == right ? True : False); 742 break; 743 case '<': 744 if (op[1] == '=') { 745 t = (left <= right ? True : False); 746 } else { 747 t = (left < right ? True : False); 748 } 749 break; 750 case '>': 751 if (op[1] == '=') { 752 t = (left >= right ? True : False); 753 } else { 754 t = (left > right ? True : False); 755 } 756 break; 757 } 758 } 759error: 760 if (doFree) 761 free(lhs); 762 break; 763 } 764 default: { 765 Boolean (*evalProc) __P((int, char *)); 766 Boolean invert = FALSE; 767 char *arg; 768 int arglen; 769 770 if (strncmp (condExpr, "defined", 7) == 0) { 771 /* 772 * Use CondDoDefined to evaluate the argument and 773 * CondGetArg to extract the argument from the 'function 774 * call'. 775 */ 776 evalProc = CondDoDefined; 777 condExpr += 7; 778 arglen = CondGetArg (&condExpr, &arg, "defined", TRUE); 779 if (arglen == 0) { 780 condExpr -= 7; 781 goto use_default; 782 } 783 } else if (strncmp (condExpr, "make", 4) == 0) { 784 /* 785 * Use CondDoMake to evaluate the argument and 786 * CondGetArg to extract the argument from the 'function 787 * call'. 788 */ 789 evalProc = CondDoMake; 790 condExpr += 4; 791 arglen = CondGetArg (&condExpr, &arg, "make", TRUE); 792 if (arglen == 0) { 793 condExpr -= 4; 794 goto use_default; 795 } 796 } else if (strncmp (condExpr, "exists", 6) == 0) { 797 /* 798 * Use CondDoExists to evaluate the argument and 799 * CondGetArg to extract the argument from the 800 * 'function call'. 801 */ 802 evalProc = CondDoExists; 803 condExpr += 6; 804 arglen = CondGetArg(&condExpr, &arg, "exists", TRUE); 805 if (arglen == 0) { 806 condExpr -= 6; 807 goto use_default; 808 } 809 } else if (strncmp(condExpr, "empty", 5) == 0) { 810 /* 811 * Use Var_Parse to parse the spec in parens and return 812 * True if the resulting string is empty. 813 */ 814 int length; 815 Boolean doFree; 816 char *val; 817 818 condExpr += 5; 819 820 for (arglen = 0; 821 condExpr[arglen] != '(' && condExpr[arglen] != '\0'; 822 arglen += 1) 823 continue; 824 825 if (condExpr[arglen] != '\0') { 826 val = Var_Parse(&condExpr[arglen - 1], VAR_CMD, 827 doEval, &length, &doFree); 828 if (val == var_Error) { 829 t = Err; 830 } else { 831 /* 832 * A variable is empty when it just contains 833 * spaces... 4/15/92, christos 834 */ 835 char *p; 836 for (p = val; *p && isspace((unsigned char)*p); p++) 837 continue; 838 t = (*p == '\0') ? True : False; 839 } 840 if (doFree) { 841 free(val); 842 } 843 /* 844 * Advance condExpr to beyond the closing ). Note that 845 * we subtract one from arglen + length b/c length 846 * is calculated from condExpr[arglen - 1]. 847 */ 848 condExpr += arglen + length - 1; 849 } else { 850 condExpr -= 5; 851 goto use_default; 852 } 853 break; 854 } else if (strncmp (condExpr, "target", 6) == 0) { 855 /* 856 * Use CondDoTarget to evaluate the argument and 857 * CondGetArg to extract the argument from the 858 * 'function call'. 859 */ 860 evalProc = CondDoTarget; 861 condExpr += 6; 862 arglen = CondGetArg(&condExpr, &arg, "target", TRUE); 863 if (arglen == 0) { 864 condExpr -= 6; 865 goto use_default; 866 } 867 } else { 868 /* 869 * The symbol is itself the argument to the default 870 * function. We advance condExpr to the end of the symbol 871 * by hand (the next whitespace, closing paren or 872 * binary operator) and set to invert the evaluation 873 * function if condInvert is TRUE. 874 */ 875 use_default: 876 invert = condInvert; 877 evalProc = condDefProc; 878 arglen = CondGetArg(&condExpr, &arg, "", FALSE); 879 } 880 881 /* 882 * Evaluate the argument using the set function. If invert 883 * is TRUE, we invert the sense of the function. 884 */ 885 t = (!doEval || (* evalProc) (arglen, arg) ? 886 (invert ? False : True) : 887 (invert ? True : False)); 888 free(arg); 889 break; 890 } 891 } 892 } else { 893 t = condPushBack; 894 condPushBack = None; 895 } 896 return (t); 897} 898 899/*- 900 *----------------------------------------------------------------------- 901 * CondT -- 902 * Parse a single term in the expression. This consists of a terminal 903 * symbol or Not and a terminal symbol (not including the binary 904 * operators): 905 * T -> defined(variable) | make(target) | exists(file) | symbol 906 * T -> ! T | ( E ) 907 * 908 * Results: 909 * True, False or Err. 910 * 911 * Side Effects: 912 * Tokens are consumed. 913 * 914 *----------------------------------------------------------------------- 915 */ 916static Token 917CondT(doEval) 918 Boolean doEval; 919{ 920 Token t; 921 922 t = CondToken(doEval); 923 924 if (t == EndOfFile) { 925 /* 926 * If we reached the end of the expression, the expression 927 * is malformed... 928 */ 929 t = Err; 930 } else if (t == LParen) { 931 /* 932 * T -> ( E ) 933 */ 934 t = CondE(doEval); 935 if (t != Err) { 936 if (CondToken(doEval) != RParen) { 937 t = Err; 938 } 939 } 940 } else if (t == Not) { 941 t = CondT(doEval); 942 if (t == True) { 943 t = False; 944 } else if (t == False) { 945 t = True; 946 } 947 } 948 return (t); 949} 950 951/*- 952 *----------------------------------------------------------------------- 953 * CondF -- 954 * Parse a conjunctive factor (nice name, wot?) 955 * F -> T && F | T 956 * 957 * Results: 958 * True, False or Err 959 * 960 * Side Effects: 961 * Tokens are consumed. 962 * 963 *----------------------------------------------------------------------- 964 */ 965static Token 966CondF(doEval) 967 Boolean doEval; 968{ 969 Token l, o; 970 971 l = CondT(doEval); 972 if (l != Err) { 973 o = CondToken(doEval); 974 975 if (o == And) { 976 /* 977 * F -> T && F 978 * 979 * If T is False, the whole thing will be False, but we have to 980 * parse the r.h.s. anyway (to throw it away). 981 * If T is True, the result is the r.h.s., be it an Err or no. 982 */ 983 if (l == True) { 984 l = CondF(doEval); 985 } else { 986 (void) CondF(FALSE); 987 } 988 } else { 989 /* 990 * F -> T 991 */ 992 CondPushBack (o); 993 } 994 } 995 return (l); 996} 997 998/*- 999 *----------------------------------------------------------------------- 1000 * CondE -- 1001 * Main expression production. 1002 * E -> F || E | F 1003 * 1004 * Results: 1005 * True, False or Err. 1006 * 1007 * Side Effects: 1008 * Tokens are, of course, consumed. 1009 * 1010 *----------------------------------------------------------------------- 1011 */ 1012static Token 1013CondE(doEval) 1014 Boolean doEval; 1015{ 1016 Token l, o; 1017 1018 l = CondF(doEval); 1019 if (l != Err) { 1020 o = CondToken(doEval); 1021 1022 if (o == Or) { 1023 /* 1024 * E -> F || E 1025 * 1026 * A similar thing occurs for ||, except that here we make sure 1027 * the l.h.s. is False before we bother to evaluate the r.h.s. 1028 * Once again, if l is False, the result is the r.h.s. and once 1029 * again if l is True, we parse the r.h.s. to throw it away. 1030 */ 1031 if (l == False) { 1032 l = CondE(doEval); 1033 } else { 1034 (void) CondE(FALSE); 1035 } 1036 } else { 1037 /* 1038 * E -> F 1039 */ 1040 CondPushBack (o); 1041 } 1042 } 1043 return (l); 1044} 1045 1046/*- 1047 *----------------------------------------------------------------------- 1048 * Cond_Eval -- 1049 * Evaluate the conditional in the passed line. The line 1050 * looks like this: 1051 * #<cond-type> <expr> 1052 * where <cond-type> is any of if, ifmake, ifnmake, ifdef, 1053 * ifndef, elif, elifmake, elifnmake, elifdef, elifndef 1054 * and <expr> consists of &&, ||, !, make(target), defined(variable) 1055 * and parenthetical groupings thereof. 1056 * 1057 * Results: 1058 * COND_PARSE if should parse lines after the conditional 1059 * COND_SKIP if should skip lines after the conditional 1060 * COND_INVALID if not a valid conditional. 1061 * 1062 * Side Effects: 1063 * None. 1064 * 1065 *----------------------------------------------------------------------- 1066 */ 1067int 1068Cond_Eval (line) 1069 char *line; /* Line to parse */ 1070{ 1071 struct If *ifp; 1072 Boolean isElse; 1073 Boolean value = FALSE; 1074 int level; /* Level at which to report errors. */ 1075 1076 level = PARSE_FATAL; 1077 1078 for (line++; *line == ' ' || *line == '\t'; line++) { 1079 continue; 1080 } 1081 1082 /* 1083 * Find what type of if we're dealing with. The result is left 1084 * in ifp and isElse is set TRUE if it's an elif line. 1085 */ 1086 if (line[0] == 'e' && line[1] == 'l') { 1087 line += 2; 1088 isElse = TRUE; 1089 } else if (strncmp (line, "endif", 5) == 0) { 1090 /* 1091 * End of a conditional section. If skipIfLevel is non-zero, that 1092 * conditional was skipped, so lines following it should also be 1093 * skipped. Hence, we return COND_SKIP. Otherwise, the conditional 1094 * was read so succeeding lines should be parsed (think about it...) 1095 * so we return COND_PARSE, unless this endif isn't paired with 1096 * a decent if. 1097 */ 1098 if (skipIfLevel != 0) { 1099 skipIfLevel -= 1; 1100 return (COND_SKIP); 1101 } else { 1102 if (condTop == MAXIF) { 1103 Parse_Error (level, "if-less endif"); 1104 return (COND_INVALID); 1105 } else { 1106 skipLine = FALSE; 1107 condTop += 1; 1108 return (COND_PARSE); 1109 } 1110 } 1111 } else { 1112 isElse = FALSE; 1113 } 1114 1115 /* 1116 * Figure out what sort of conditional it is -- what its default 1117 * function is, etc. -- by looking in the table of valid "ifs" 1118 */ 1119 for (ifp = ifs; ifp->form != (char *)0; ifp++) { 1120 if (strncmp (ifp->form, line, ifp->formlen) == 0) { 1121 break; 1122 } 1123 } 1124 1125 if (ifp->form == (char *) 0) { 1126 /* 1127 * Nothing fit. If the first word on the line is actually 1128 * "else", it's a valid conditional whose value is the inverse 1129 * of the previous if we parsed. 1130 */ 1131 if (isElse && (line[0] == 's') && (line[1] == 'e')) { 1132 if (condTop == MAXIF) { 1133 Parse_Error (level, "if-less else"); 1134 return (COND_INVALID); 1135 } else if (skipIfLevel == 0) { 1136 value = !condStack[condTop]; 1137 } else { 1138 return (COND_SKIP); 1139 } 1140 } else { 1141 /* 1142 * Not a valid conditional type. No error... 1143 */ 1144 return (COND_INVALID); 1145 } 1146 } else { 1147 if (isElse) { 1148 if (condTop == MAXIF) { 1149 Parse_Error (level, "if-less elif"); 1150 return (COND_INVALID); 1151 } else if (skipIfLevel != 0) { 1152 /* 1153 * If skipping this conditional, just ignore the whole thing. 1154 * If we don't, the user might be employing a variable that's 1155 * undefined, for which there's an enclosing ifdef that 1156 * we're skipping... 1157 */ 1158 return(COND_SKIP); 1159 } 1160 } else if (skipLine) { 1161 /* 1162 * Don't even try to evaluate a conditional that's not an else if 1163 * we're skipping things... 1164 */ 1165 skipIfLevel += 1; 1166 return(COND_SKIP); 1167 } 1168 1169 /* 1170 * Initialize file-global variables for parsing 1171 */ 1172 condDefProc = ifp->defProc; 1173 condInvert = ifp->doNot; 1174 1175 line += ifp->formlen; 1176 1177 while (*line == ' ' || *line == '\t') { 1178 line++; 1179 } 1180 1181 condExpr = line; 1182 condPushBack = None; 1183 1184 switch (CondE(TRUE)) { 1185 case True: 1186 if (CondToken(TRUE) == EndOfFile) { 1187 value = TRUE; 1188 break; 1189 } 1190 goto err; 1191 /*FALLTHRU*/ 1192 case False: 1193 if (CondToken(TRUE) == EndOfFile) { 1194 value = FALSE; 1195 break; 1196 } 1197 /*FALLTHRU*/ 1198 case Err: 1199 err: 1200 Parse_Error (level, "Malformed conditional (%s)", 1201 line); 1202 return (COND_INVALID); 1203 default: 1204 break; 1205 } 1206 } 1207 if (!isElse) { 1208 condTop -= 1; 1209 } else if ((skipIfLevel != 0) || condStack[condTop]) { 1210 /* 1211 * If this is an else-type conditional, it should only take effect 1212 * if its corresponding if was evaluated and FALSE. If its if was 1213 * TRUE or skipped, we return COND_SKIP (and start skipping in case 1214 * we weren't already), leaving the stack unmolested so later elif's 1215 * don't screw up... 1216 */ 1217 skipLine = TRUE; 1218 return (COND_SKIP); 1219 } 1220 1221 if (condTop < 0) { 1222 /* 1223 * This is the one case where we can definitely proclaim a fatal 1224 * error. If we don't, we're hosed. 1225 */ 1226 Parse_Error (PARSE_FATAL, "Too many nested if's. %d max.", MAXIF); 1227 return (COND_INVALID); 1228 } else { 1229 condStack[condTop] = value; 1230 skipLine = !value; 1231 return (value ? COND_PARSE : COND_SKIP); 1232 } 1233} 1234 1235/*- 1236 *----------------------------------------------------------------------- 1237 * Cond_End -- 1238 * Make sure everything's clean at the end of a makefile. 1239 * 1240 * Results: 1241 * None. 1242 * 1243 * Side Effects: 1244 * Parse_Error will be called if open conditionals are around. 1245 * 1246 *----------------------------------------------------------------------- 1247 */ 1248void 1249Cond_End() 1250{ 1251 if (condTop != MAXIF) { 1252 Parse_Error(PARSE_FATAL, "%d open conditional%s", MAXIF-condTop, 1253 MAXIF-condTop == 1 ? "" : "s"); 1254 } 1255 condTop = MAXIF; 1256} 1257