cond.c revision 94584
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 * @(#)cond.c 8.2 (Berkeley) 1/2/94 39 */ 40 41#ifndef lint 42#include <sys/cdefs.h> 43__RCSID("$FreeBSD: head/usr.bin/make/cond.c 94584 2002-04-13 10:05:30Z obrien $"); 44#endif /* not lint */ 45 46/*- 47 * cond.c -- 48 * Functions to handle conditionals in a makefile. 49 * 50 * Interface: 51 * Cond_Eval Evaluate the conditional in the passed line. 52 * 53 */ 54 55#include <ctype.h> 56#include <math.h> 57#include "make.h" 58#include "hash.h" 59#include "dir.h" 60#include "buf.h" 61 62/* 63 * The parsing of conditional expressions is based on this grammar: 64 * E -> F || E 65 * E -> F 66 * F -> T && F 67 * F -> T 68 * T -> defined(variable) 69 * T -> make(target) 70 * T -> exists(file) 71 * T -> empty(varspec) 72 * T -> target(name) 73 * T -> symbol 74 * T -> $(varspec) op value 75 * T -> $(varspec) == "string" 76 * T -> $(varspec) != "string" 77 * T -> ( E ) 78 * T -> ! T 79 * op -> == | != | > | < | >= | <= 80 * 81 * 'symbol' is some other symbol to which the default function (condDefProc) 82 * is applied. 83 * 84 * Tokens are scanned from the 'condExpr' string. The scanner (CondToken) 85 * will return And for '&' and '&&', Or for '|' and '||', Not for '!', 86 * LParen for '(', RParen for ')' and will evaluate the other terminal 87 * symbols, using either the default function or the function given in the 88 * terminal, and return the result as either True or False. 89 * 90 * All Non-Terminal functions (CondE, CondF and CondT) return Err on error. 91 */ 92typedef enum { 93 And, Or, Not, True, False, LParen, RParen, EndOfFile, None, Err 94} Token; 95 96/*- 97 * Structures to handle elegantly the different forms of #if's. The 98 * last two fields are stored in condInvert and condDefProc, respectively. 99 */ 100static void CondPushBack(Token); 101static int CondGetArg(char **, char **, char *, Boolean); 102static Boolean CondDoDefined(int, char *); 103static int CondStrMatch(void *, void *); 104static Boolean CondDoMake(int, char *); 105static Boolean CondDoExists(int, char *); 106static Boolean CondDoTarget(int, char *); 107static char * CondCvtArg(char *, double *); 108static Token CondToken(Boolean); 109static Token CondT(Boolean); 110static Token CondF(Boolean); 111static Token CondE(Boolean); 112 113static struct If { 114 char *form; /* Form of if */ 115 int formlen; /* Length of form */ 116 Boolean doNot; /* TRUE if default function should be negated */ 117 Boolean (*defProc)(int, char *); /* Default function to apply */ 118} ifs[] = { 119 { "ifdef", 5, FALSE, CondDoDefined }, 120 { "ifndef", 6, TRUE, CondDoDefined }, 121 { "ifmake", 6, FALSE, CondDoMake }, 122 { "ifnmake", 7, TRUE, CondDoMake }, 123 { "if", 2, FALSE, CondDoDefined }, 124 { NULL, 0, FALSE, NULL } 125}; 126 127static Boolean condInvert; /* Invert the default function */ 128static Boolean (*condDefProc) /* Default function to apply */ 129(int, char *); 130static char *condExpr; /* The expression to parse */ 131static Token condPushBack=None; /* Single push-back token used in 132 * parsing */ 133 134#define MAXIF 30 /* greatest depth of #if'ing */ 135 136static Boolean condStack[MAXIF]; /* Stack of conditionals's values */ 137static int condTop = MAXIF; /* Top-most conditional */ 138static int skipIfLevel=0; /* Depth of skipped conditionals */ 139static Boolean skipLine = FALSE; /* Whether the parse module is skipping 140 * lines */ 141 142/*- 143 *----------------------------------------------------------------------- 144 * CondPushBack -- 145 * Push back the most recent token read. We only need one level of 146 * this, so the thing is just stored in 'condPushback'. 147 * 148 * Results: 149 * None. 150 * 151 * Side Effects: 152 * condPushback is overwritten. 153 * 154 *----------------------------------------------------------------------- 155 */ 156static void 157CondPushBack (t) 158 Token t; /* Token to push back into the "stream" */ 159{ 160 condPushBack = t; 161} 162 163/*- 164 *----------------------------------------------------------------------- 165 * CondGetArg -- 166 * Find the argument of a built-in function. 167 * 168 * Results: 169 * The length of the argument and the address of the argument. 170 * 171 * Side Effects: 172 * The pointer is set to point to the closing parenthesis of the 173 * function call. 174 * 175 *----------------------------------------------------------------------- 176 */ 177static int 178CondGetArg (linePtr, argPtr, func, parens) 179 char **linePtr; 180 char **argPtr; 181 char *func; 182 Boolean parens; /* TRUE if arg should be bounded by parens */ 183{ 184 char *cp; 185 int argLen; 186 Buffer buf; 187 188 cp = *linePtr; 189 if (parens) { 190 while (*cp != '(' && *cp != '\0') { 191 cp++; 192 } 193 if (*cp == '(') { 194 cp++; 195 } 196 } 197 198 if (*cp == '\0') { 199 /* 200 * No arguments whatsoever. Because 'make' and 'defined' aren't really 201 * "reserved words", we don't print a message. I think this is better 202 * than hitting the user with a warning message every time s/he uses 203 * the word 'make' or 'defined' at the beginning of a symbol... 204 */ 205 *argPtr = cp; 206 return (0); 207 } 208 209 while (*cp == ' ' || *cp == '\t') { 210 cp++; 211 } 212 213 /* 214 * Create a buffer for the argument and start it out at 16 characters 215 * long. Why 16? Why not? 216 */ 217 buf = Buf_Init(16); 218 219 while ((strchr(" \t)&|", *cp) == (char *)NULL) && (*cp != '\0')) { 220 if (*cp == '$') { 221 /* 222 * Parse the variable spec and install it as part of the argument 223 * if it's valid. We tell Var_Parse to complain on an undefined 224 * variable, so we don't do it too. Nor do we return an error, 225 * though perhaps we should... 226 */ 227 char *cp2; 228 int len; 229 Boolean doFree; 230 231 cp2 = Var_Parse(cp, VAR_CMD, TRUE, &len, &doFree); 232 233 Buf_AddBytes(buf, strlen(cp2), (Byte *)cp2); 234 if (doFree) { 235 free(cp2); 236 } 237 cp += len; 238 } else { 239 Buf_AddByte(buf, (Byte)*cp); 240 cp++; 241 } 242 } 243 244 Buf_AddByte(buf, (Byte)'\0'); 245 *argPtr = (char *)Buf_GetAll(buf, &argLen); 246 Buf_Destroy(buf, FALSE); 247 248 while (*cp == ' ' || *cp == '\t') { 249 cp++; 250 } 251 if (parens && *cp != ')') { 252 Parse_Error (PARSE_WARNING, "Missing closing parenthesis for %s()", 253 func); 254 return (0); 255 } else if (parens) { 256 /* 257 * Advance pointer past close parenthesis. 258 */ 259 cp++; 260 } 261 262 *linePtr = cp; 263 return (argLen); 264} 265 266/*- 267 *----------------------------------------------------------------------- 268 * CondDoDefined -- 269 * Handle the 'defined' function for conditionals. 270 * 271 * Results: 272 * TRUE if the given variable is defined. 273 * 274 * Side Effects: 275 * None. 276 * 277 *----------------------------------------------------------------------- 278 */ 279static Boolean 280CondDoDefined (argLen, arg) 281 int argLen; 282 char *arg; 283{ 284 char savec = arg[argLen]; 285 char *p1; 286 Boolean result; 287 288 arg[argLen] = '\0'; 289 if (Var_Value (arg, VAR_CMD, &p1) != (char *)NULL) { 290 result = TRUE; 291 } else { 292 result = FALSE; 293 } 294 efree(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 void * string; 316 void * 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, (void *)arg, CondStrMatch) == NULL) { 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 != NULL) && !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 address of the first character after the last valid 431 * character of the converted number. 432 * 433 * Side Effects: 434 * Can change 'value' even if string is not a valid number. 435 * 436 * 437 *----------------------------------------------------------------------- 438 */ 439static char * 440CondCvtArg(str, value) 441 char *str; 442 double *value; 443{ 444 if ((*str == '0') && (str[1] == 'x')) { 445 long i; 446 447 for (str += 2, i = 0; ; str++) { 448 int x; 449 if (isdigit((unsigned char) *str)) 450 x = *str - '0'; 451 else if (isxdigit((unsigned char) *str)) 452 x = 10 + *str - isupper((unsigned char) *str) ? 'A' : 'a'; 453 else { 454 *value = (double) i; 455 return str; 456 } 457 i = (i << 4) + x; 458 } 459 } 460 else { 461 char *eptr; 462 *value = strtod(str, &eptr); 463 return eptr; 464 } 465} 466 467/*- 468 *----------------------------------------------------------------------- 469 * CondToken -- 470 * Return the next token from the input. 471 * 472 * Results: 473 * A Token for the next lexical token in the stream. 474 * 475 * Side Effects: 476 * condPushback will be set back to None if it is used. 477 * 478 *----------------------------------------------------------------------- 479 */ 480static Token 481CondToken(doEval) 482 Boolean doEval; 483{ 484 Token t; 485 486 if (condPushBack == None) { 487 while (*condExpr == ' ' || *condExpr == '\t') { 488 condExpr++; 489 } 490 switch (*condExpr) { 491 case '(': 492 t = LParen; 493 condExpr++; 494 break; 495 case ')': 496 t = RParen; 497 condExpr++; 498 break; 499 case '|': 500 if (condExpr[1] == '|') { 501 condExpr++; 502 } 503 condExpr++; 504 t = Or; 505 break; 506 case '&': 507 if (condExpr[1] == '&') { 508 condExpr++; 509 } 510 condExpr++; 511 t = And; 512 break; 513 case '!': 514 t = Not; 515 condExpr++; 516 break; 517 case '\n': 518 case '\0': 519 t = EndOfFile; 520 break; 521 case '$': { 522 char *lhs; 523 char *rhs; 524 char *op; 525 int varSpecLen; 526 Boolean doFree; 527 528 /* 529 * Parse the variable spec and skip over it, saving its 530 * value in lhs. 531 */ 532 t = Err; 533 lhs = Var_Parse(condExpr, VAR_CMD, doEval,&varSpecLen,&doFree); 534 if (lhs == var_Error) { 535 /* 536 * Even if !doEval, we still report syntax errors, which 537 * is what getting var_Error back with !doEval means. 538 */ 539 return(Err); 540 } 541 condExpr += varSpecLen; 542 543 if (!isspace((unsigned char) *condExpr) && 544 strchr("!=><", *condExpr) == NULL) { 545 Buffer buf; 546 char *cp; 547 548 buf = Buf_Init(0); 549 550 for (cp = lhs; *cp; cp++) 551 Buf_AddByte(buf, (Byte)*cp); 552 553 if (doFree) 554 free(lhs); 555 556 for (;*condExpr && !isspace((unsigned char) *condExpr); 557 condExpr++) 558 Buf_AddByte(buf, (Byte)*condExpr); 559 560 Buf_AddByte(buf, (Byte)'\0'); 561 lhs = (char *)Buf_GetAll(buf, &varSpecLen); 562 Buf_Destroy(buf, FALSE); 563 564 doFree = TRUE; 565 } 566 567 /* 568 * Skip whitespace to get to the operator 569 */ 570 while (isspace((unsigned char) *condExpr)) 571 condExpr++; 572 573 /* 574 * Make sure the operator is a valid one. If it isn't a 575 * known relational operator, pretend we got a 576 * != 0 comparison. 577 */ 578 op = condExpr; 579 switch (*condExpr) { 580 case '!': 581 case '=': 582 case '<': 583 case '>': 584 if (condExpr[1] == '=') { 585 condExpr += 2; 586 } else { 587 condExpr += 1; 588 } 589 break; 590 default: 591 op = "!="; 592 rhs = "0"; 593 594 goto do_compare; 595 } 596 while (isspace((unsigned char) *condExpr)) { 597 condExpr++; 598 } 599 if (*condExpr == '\0') { 600 Parse_Error(PARSE_WARNING, 601 "Missing right-hand-side of operator"); 602 goto error; 603 } 604 rhs = condExpr; 605do_compare: 606 if (*rhs == '"') { 607 /* 608 * Doing a string comparison. Only allow == and != for 609 * operators. 610 */ 611 char *string; 612 char *cp, *cp2; 613 int qt; 614 Buffer buf; 615 616do_string_compare: 617 if (((*op != '!') && (*op != '=')) || (op[1] != '=')) { 618 Parse_Error(PARSE_WARNING, 619 "String comparison operator should be either == or !="); 620 goto error; 621 } 622 623 buf = Buf_Init(0); 624 qt = *rhs == '"' ? 1 : 0; 625 626 for (cp = &rhs[qt]; 627 ((qt && (*cp != '"')) || 628 (!qt && strchr(" \t)", *cp) == NULL)) && 629 (*cp != '\0'); cp++) { 630 if ((*cp == '\\') && (cp[1] != '\0')) { 631 /* 632 * Backslash escapes things -- skip over next 633 * character, if it exists. 634 */ 635 cp++; 636 Buf_AddByte(buf, (Byte)*cp); 637 } else if (*cp == '$') { 638 int len; 639 Boolean freeIt; 640 641 cp2 = Var_Parse(cp, VAR_CMD, doEval,&len, &freeIt); 642 if (cp2 != var_Error) { 643 Buf_AddBytes(buf, strlen(cp2), (Byte *)cp2); 644 if (freeIt) { 645 free(cp2); 646 } 647 cp += len - 1; 648 } else { 649 Buf_AddByte(buf, (Byte)*cp); 650 } 651 } else { 652 Buf_AddByte(buf, (Byte)*cp); 653 } 654 } 655 656 Buf_AddByte(buf, (Byte)0); 657 658 string = (char *)Buf_GetAll(buf, (int *)0); 659 Buf_Destroy(buf, FALSE); 660 661 if (DEBUG(COND)) { 662 printf("lhs = \"%s\", rhs = \"%s\", op = %.2s\n", 663 lhs, string, op); 664 } 665 /* 666 * Null-terminate rhs and perform the comparison. 667 * t is set to the result. 668 */ 669 if (*op == '=') { 670 t = strcmp(lhs, string) ? False : True; 671 } else { 672 t = strcmp(lhs, string) ? True : False; 673 } 674 free(string); 675 if (rhs == condExpr) { 676 if (!qt && *cp == ')') 677 condExpr = cp; 678 else 679 condExpr = cp + 1; 680 } 681 } else { 682 /* 683 * rhs is either a float or an integer. Convert both the 684 * lhs and the rhs to a double and compare the two. 685 */ 686 double left, right; 687 char *string; 688 689 if (*CondCvtArg(lhs, &left) != '\0') 690 goto do_string_compare; 691 if (*rhs == '$') { 692 int len; 693 Boolean freeIt; 694 695 string = Var_Parse(rhs, VAR_CMD, doEval,&len,&freeIt); 696 if (string == var_Error) { 697 right = 0.0; 698 } else { 699 if (*CondCvtArg(string, &right) != '\0') { 700 if (freeIt) 701 free(string); 702 goto do_string_compare; 703 } 704 if (freeIt) 705 free(string); 706 if (rhs == condExpr) 707 condExpr += len; 708 } 709 } else { 710 char *c = CondCvtArg(rhs, &right); 711 if (*c != '\0' && !isspace(*c)) 712 goto do_string_compare; 713 if (rhs == condExpr) { 714 /* 715 * Skip over the right-hand side 716 */ 717 while(!isspace((unsigned char) *condExpr) && 718 (*condExpr != '\0')) { 719 condExpr++; 720 } 721 } 722 } 723 724 if (DEBUG(COND)) { 725 printf("left = %f, right = %f, op = %.2s\n", left, 726 right, op); 727 } 728 switch(op[0]) { 729 case '!': 730 if (op[1] != '=') { 731 Parse_Error(PARSE_WARNING, 732 "Unknown operator"); 733 goto error; 734 } 735 t = (left != right ? True : False); 736 break; 737 case '=': 738 if (op[1] != '=') { 739 Parse_Error(PARSE_WARNING, 740 "Unknown operator"); 741 goto error; 742 } 743 t = (left == right ? True : False); 744 break; 745 case '<': 746 if (op[1] == '=') { 747 t = (left <= right ? True : False); 748 } else { 749 t = (left < right ? True : False); 750 } 751 break; 752 case '>': 753 if (op[1] == '=') { 754 t = (left >= right ? True : False); 755 } else { 756 t = (left > right ? True : False); 757 } 758 break; 759 } 760 } 761error: 762 if (doFree) 763 free(lhs); 764 break; 765 } 766 default: { 767 Boolean (*evalProc)(int, char *); 768 Boolean invert = FALSE; 769 char *arg; 770 int arglen; 771 772 if (strncmp (condExpr, "defined", 7) == 0) { 773 /* 774 * Use CondDoDefined to evaluate the argument and 775 * CondGetArg to extract the argument from the 'function 776 * call'. 777 */ 778 evalProc = CondDoDefined; 779 condExpr += 7; 780 arglen = CondGetArg (&condExpr, &arg, "defined", TRUE); 781 if (arglen == 0) { 782 condExpr -= 7; 783 goto use_default; 784 } 785 } else if (strncmp (condExpr, "make", 4) == 0) { 786 /* 787 * Use CondDoMake to evaluate the argument and 788 * CondGetArg to extract the argument from the 'function 789 * call'. 790 */ 791 evalProc = CondDoMake; 792 condExpr += 4; 793 arglen = CondGetArg (&condExpr, &arg, "make", TRUE); 794 if (arglen == 0) { 795 condExpr -= 4; 796 goto use_default; 797 } 798 } else if (strncmp (condExpr, "exists", 6) == 0) { 799 /* 800 * Use CondDoExists to evaluate the argument and 801 * CondGetArg to extract the argument from the 802 * 'function call'. 803 */ 804 evalProc = CondDoExists; 805 condExpr += 6; 806 arglen = CondGetArg(&condExpr, &arg, "exists", TRUE); 807 if (arglen == 0) { 808 condExpr -= 6; 809 goto use_default; 810 } 811 } else if (strncmp(condExpr, "empty", 5) == 0) { 812 /* 813 * Use Var_Parse to parse the spec in parens and return 814 * True if the resulting string is empty. 815 */ 816 int length; 817 Boolean doFree; 818 char *val; 819 820 condExpr += 5; 821 822 for (arglen = 0; 823 condExpr[arglen] != '(' && condExpr[arglen] != '\0'; 824 arglen += 1) 825 continue; 826 827 if (condExpr[arglen] != '\0') { 828 val = Var_Parse(&condExpr[arglen - 1], VAR_CMD, 829 doEval, &length, &doFree); 830 if (val == var_Error) { 831 t = Err; 832 } else { 833 /* 834 * A variable is empty when it just contains 835 * spaces... 4/15/92, christos 836 */ 837 char *p; 838 for (p = val; *p && isspace((unsigned char)*p); p++) 839 continue; 840 t = (*p == '\0') ? True : False; 841 } 842 if (doFree) { 843 free(val); 844 } 845 /* 846 * Advance condExpr to beyond the closing ). Note that 847 * we subtract one from arglen + length b/c length 848 * is calculated from condExpr[arglen - 1]. 849 */ 850 condExpr += arglen + length - 1; 851 } else { 852 condExpr -= 5; 853 goto use_default; 854 } 855 break; 856 } else if (strncmp (condExpr, "target", 6) == 0) { 857 /* 858 * Use CondDoTarget to evaluate the argument and 859 * CondGetArg to extract the argument from the 860 * 'function call'. 861 */ 862 evalProc = CondDoTarget; 863 condExpr += 6; 864 arglen = CondGetArg(&condExpr, &arg, "target", TRUE); 865 if (arglen == 0) { 866 condExpr -= 6; 867 goto use_default; 868 } 869 } else { 870 /* 871 * The symbol is itself the argument to the default 872 * function. We advance condExpr to the end of the symbol 873 * by hand (the next whitespace, closing paren or 874 * binary operator) and set to invert the evaluation 875 * function if condInvert is TRUE. 876 */ 877 use_default: 878 invert = condInvert; 879 evalProc = condDefProc; 880 arglen = CondGetArg(&condExpr, &arg, "", FALSE); 881 } 882 883 /* 884 * Evaluate the argument using the set function. If invert 885 * is TRUE, we invert the sense of the function. 886 */ 887 t = (!doEval || (* evalProc) (arglen, arg) ? 888 (invert ? False : True) : 889 (invert ? True : False)); 890 free(arg); 891 break; 892 } 893 } 894 } else { 895 t = condPushBack; 896 condPushBack = None; 897 } 898 return (t); 899} 900 901/*- 902 *----------------------------------------------------------------------- 903 * CondT -- 904 * Parse a single term in the expression. This consists of a terminal 905 * symbol or Not and a terminal symbol (not including the binary 906 * operators): 907 * T -> defined(variable) | make(target) | exists(file) | symbol 908 * T -> ! T | ( E ) 909 * 910 * Results: 911 * True, False or Err. 912 * 913 * Side Effects: 914 * Tokens are consumed. 915 * 916 *----------------------------------------------------------------------- 917 */ 918static Token 919CondT(doEval) 920 Boolean doEval; 921{ 922 Token t; 923 924 t = CondToken(doEval); 925 926 if (t == EndOfFile) { 927 /* 928 * If we reached the end of the expression, the expression 929 * is malformed... 930 */ 931 t = Err; 932 } else if (t == LParen) { 933 /* 934 * T -> ( E ) 935 */ 936 t = CondE(doEval); 937 if (t != Err) { 938 if (CondToken(doEval) != RParen) { 939 t = Err; 940 } 941 } 942 } else if (t == Not) { 943 t = CondT(doEval); 944 if (t == True) { 945 t = False; 946 } else if (t == False) { 947 t = True; 948 } 949 } 950 return (t); 951} 952 953/*- 954 *----------------------------------------------------------------------- 955 * CondF -- 956 * Parse a conjunctive factor (nice name, wot?) 957 * F -> T && F | T 958 * 959 * Results: 960 * True, False or Err 961 * 962 * Side Effects: 963 * Tokens are consumed. 964 * 965 *----------------------------------------------------------------------- 966 */ 967static Token 968CondF(doEval) 969 Boolean doEval; 970{ 971 Token l, o; 972 973 l = CondT(doEval); 974 if (l != Err) { 975 o = CondToken(doEval); 976 977 if (o == And) { 978 /* 979 * F -> T && F 980 * 981 * If T is False, the whole thing will be False, but we have to 982 * parse the r.h.s. anyway (to throw it away). 983 * If T is True, the result is the r.h.s., be it an Err or no. 984 */ 985 if (l == True) { 986 l = CondF(doEval); 987 } else { 988 (void) CondF(FALSE); 989 } 990 } else { 991 /* 992 * F -> T 993 */ 994 CondPushBack (o); 995 } 996 } 997 return (l); 998} 999 1000/*- 1001 *----------------------------------------------------------------------- 1002 * CondE -- 1003 * Main expression production. 1004 * E -> F || E | F 1005 * 1006 * Results: 1007 * True, False or Err. 1008 * 1009 * Side Effects: 1010 * Tokens are, of course, consumed. 1011 * 1012 *----------------------------------------------------------------------- 1013 */ 1014static Token 1015CondE(doEval) 1016 Boolean doEval; 1017{ 1018 Token l, o; 1019 1020 l = CondF(doEval); 1021 if (l != Err) { 1022 o = CondToken(doEval); 1023 1024 if (o == Or) { 1025 /* 1026 * E -> F || E 1027 * 1028 * A similar thing occurs for ||, except that here we make sure 1029 * the l.h.s. is False before we bother to evaluate the r.h.s. 1030 * Once again, if l is False, the result is the r.h.s. and once 1031 * again if l is True, we parse the r.h.s. to throw it away. 1032 */ 1033 if (l == False) { 1034 l = CondE(doEval); 1035 } else { 1036 (void) CondE(FALSE); 1037 } 1038 } else { 1039 /* 1040 * E -> F 1041 */ 1042 CondPushBack (o); 1043 } 1044 } 1045 return (l); 1046} 1047 1048/*- 1049 *----------------------------------------------------------------------- 1050 * Cond_Eval -- 1051 * Evaluate the conditional in the passed line. The line 1052 * looks like this: 1053 * #<cond-type> <expr> 1054 * where <cond-type> is any of if, ifmake, ifnmake, ifdef, 1055 * ifndef, elif, elifmake, elifnmake, elifdef, elifndef 1056 * and <expr> consists of &&, ||, !, make(target), defined(variable) 1057 * and parenthetical groupings thereof. 1058 * 1059 * Results: 1060 * COND_PARSE if should parse lines after the conditional 1061 * COND_SKIP if should skip lines after the conditional 1062 * COND_INVALID if not a valid conditional. 1063 * 1064 * Side Effects: 1065 * None. 1066 * 1067 *----------------------------------------------------------------------- 1068 */ 1069int 1070Cond_Eval (line) 1071 char *line; /* Line to parse */ 1072{ 1073 struct If *ifp; 1074 Boolean isElse; 1075 Boolean value = FALSE; 1076 int level; /* Level at which to report errors. */ 1077 1078 level = PARSE_FATAL; 1079 1080 for (line++; *line == ' ' || *line == '\t'; line++) { 1081 continue; 1082 } 1083 1084 /* 1085 * Find what type of if we're dealing with. The result is left 1086 * in ifp and isElse is set TRUE if it's an elif line. 1087 */ 1088 if (line[0] == 'e' && line[1] == 'l') { 1089 line += 2; 1090 isElse = TRUE; 1091 } else if (strncmp (line, "endif", 5) == 0) { 1092 /* 1093 * End of a conditional section. If skipIfLevel is non-zero, that 1094 * conditional was skipped, so lines following it should also be 1095 * skipped. Hence, we return COND_SKIP. Otherwise, the conditional 1096 * was read so succeeding lines should be parsed (think about it...) 1097 * so we return COND_PARSE, unless this endif isn't paired with 1098 * a decent if. 1099 */ 1100 if (skipIfLevel != 0) { 1101 skipIfLevel -= 1; 1102 return (COND_SKIP); 1103 } else { 1104 if (condTop == MAXIF) { 1105 Parse_Error (level, "if-less endif"); 1106 return (COND_INVALID); 1107 } else { 1108 skipLine = FALSE; 1109 condTop += 1; 1110 return (COND_PARSE); 1111 } 1112 } 1113 } else { 1114 isElse = FALSE; 1115 } 1116 1117 /* 1118 * Figure out what sort of conditional it is -- what its default 1119 * function is, etc. -- by looking in the table of valid "ifs" 1120 */ 1121 for (ifp = ifs; ifp->form != (char *)0; ifp++) { 1122 if (strncmp (ifp->form, line, ifp->formlen) == 0) { 1123 break; 1124 } 1125 } 1126 1127 if (ifp->form == (char *) 0) { 1128 /* 1129 * Nothing fit. If the first word on the line is actually 1130 * "else", it's a valid conditional whose value is the inverse 1131 * of the previous if we parsed. 1132 */ 1133 if (isElse && (line[0] == 's') && (line[1] == 'e')) { 1134 if (condTop == MAXIF) { 1135 Parse_Error (level, "if-less else"); 1136 return (COND_INVALID); 1137 } else if (skipIfLevel == 0) { 1138 value = !condStack[condTop]; 1139 } else { 1140 return (COND_SKIP); 1141 } 1142 } else { 1143 /* 1144 * Not a valid conditional type. No error... 1145 */ 1146 return (COND_INVALID); 1147 } 1148 } else { 1149 if (isElse) { 1150 if (condTop == MAXIF) { 1151 Parse_Error (level, "if-less elif"); 1152 return (COND_INVALID); 1153 } else if (skipIfLevel != 0) { 1154 /* 1155 * If skipping this conditional, just ignore the whole thing. 1156 * If we don't, the user might be employing a variable that's 1157 * undefined, for which there's an enclosing ifdef that 1158 * we're skipping... 1159 */ 1160 return(COND_SKIP); 1161 } 1162 } else if (skipLine) { 1163 /* 1164 * Don't even try to evaluate a conditional that's not an else if 1165 * we're skipping things... 1166 */ 1167 skipIfLevel += 1; 1168 return(COND_SKIP); 1169 } 1170 1171 /* 1172 * Initialize file-global variables for parsing 1173 */ 1174 condDefProc = ifp->defProc; 1175 condInvert = ifp->doNot; 1176 1177 line += ifp->formlen; 1178 1179 while (*line == ' ' || *line == '\t') { 1180 line++; 1181 } 1182 1183 condExpr = line; 1184 condPushBack = None; 1185 1186 switch (CondE(TRUE)) { 1187 case True: 1188 if (CondToken(TRUE) == EndOfFile) { 1189 value = TRUE; 1190 break; 1191 } 1192 goto err; 1193 /*FALLTHRU*/ 1194 case False: 1195 if (CondToken(TRUE) == EndOfFile) { 1196 value = FALSE; 1197 break; 1198 } 1199 /*FALLTHRU*/ 1200 case Err: 1201 err: 1202 Parse_Error (level, "Malformed conditional (%s)", 1203 line); 1204 return (COND_INVALID); 1205 default: 1206 break; 1207 } 1208 } 1209 if (!isElse) { 1210 condTop -= 1; 1211 } else if ((skipIfLevel != 0) || condStack[condTop]) { 1212 /* 1213 * If this is an else-type conditional, it should only take effect 1214 * if its corresponding if was evaluated and FALSE. If its if was 1215 * TRUE or skipped, we return COND_SKIP (and start skipping in case 1216 * we weren't already), leaving the stack unmolested so later elif's 1217 * don't screw up... 1218 */ 1219 skipLine = TRUE; 1220 return (COND_SKIP); 1221 } 1222 1223 if (condTop < 0) { 1224 /* 1225 * This is the one case where we can definitely proclaim a fatal 1226 * error. If we don't, we're hosed. 1227 */ 1228 Parse_Error (PARSE_FATAL, "Too many nested if's. %d max.", MAXIF); 1229 return (COND_INVALID); 1230 } else { 1231 condStack[condTop] = value; 1232 skipLine = !value; 1233 return (value ? COND_PARSE : COND_SKIP); 1234 } 1235} 1236 1237/*- 1238 *----------------------------------------------------------------------- 1239 * Cond_End -- 1240 * Make sure everything's clean at the end of a makefile. 1241 * 1242 * Results: 1243 * None. 1244 * 1245 * Side Effects: 1246 * Parse_Error will be called if open conditionals are around. 1247 * 1248 *----------------------------------------------------------------------- 1249 */ 1250void 1251Cond_End() 1252{ 1253 if (condTop != MAXIF) { 1254 Parse_Error(PARSE_FATAL, "%d open conditional%s", MAXIF-condTop, 1255 MAXIF-condTop == 1 ? "" : "s"); 1256 } 1257 condTop = MAXIF; 1258} 1259