cond.c revision 138264
1/* 2 * Copyright (c) 1988, 1989, 1990, 1993 3 * The Regents of the University of California. All rights reserved. 4 * Copyright (c) 1988, 1989 by Adam de Boor 5 * Copyright (c) 1989 by Berkeley Softworks 6 * All rights reserved. 7 * 8 * This code is derived from software contributed to Berkeley by 9 * Adam de Boor. 10 * 11 * Redistribution and use in source and binary forms, with or without 12 * modification, are permitted provided that the following conditions 13 * are met: 14 * 1. Redistributions of source code must retain the above copyright 15 * notice, this list of conditions and the following disclaimer. 16 * 2. Redistributions in binary form must reproduce the above copyright 17 * notice, this list of conditions and the following disclaimer in the 18 * documentation and/or other materials provided with the distribution. 19 * 3. All advertising materials mentioning features or use of this software 20 * must display the following acknowledgement: 21 * This product includes software developed by the University of 22 * California, Berkeley and its contributors. 23 * 4. Neither the name of the University nor the names of its contributors 24 * may be used to endorse or promote products derived from this software 25 * without specific prior written permission. 26 * 27 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 28 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 29 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 30 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 31 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 32 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 33 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 34 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 35 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 36 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 37 * SUCH DAMAGE. 38 * 39 * @(#)cond.c 8.2 (Berkeley) 1/2/94 40 */ 41 42#include <sys/cdefs.h> 43__FBSDID("$FreeBSD: head/usr.bin/make/cond.c 138264 2004-12-01 10:29:20Z harti $"); 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(Token); 100static int CondGetArg(char **, char **, char *, Boolean); 101static Boolean CondDoDefined(int, char *); 102static int CondStrMatch(void *, void *); 103static Boolean CondDoMake(int, char *); 104static Boolean CondDoExists(int, char *); 105static Boolean CondDoTarget(int, char *); 106static char * CondCvtArg(char *, double *); 107static Token CondToken(Boolean); 108static Token CondT(Boolean); 109static Token CondF(Boolean); 110static Token CondE(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)(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(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 condLineno[MAXIF]; /* Line numbers of the opening .if */ 137static int condTop = MAXIF; /* Top-most conditional */ 138static int skipIfLevel=0; /* Depth of skipped conditionals */ 139static int skipIfLineno[MAXIF]; /* Line numbers of skipped .ifs */ 140static Boolean skipLine = FALSE; /* Whether the parse module is skipping 141 * lines */ 142 143/*- 144 *----------------------------------------------------------------------- 145 * CondPushBack -- 146 * Push back the most recent token read. We only need one level of 147 * this, so the thing is just stored in 'condPushback'. 148 * 149 * Results: 150 * None. 151 * 152 * Side Effects: 153 * condPushback is overwritten. 154 * 155 *----------------------------------------------------------------------- 156 */ 157static void 158CondPushBack(Token t) 159{ 160 161 condPushBack = t; 162} 163 164/*- 165 *----------------------------------------------------------------------- 166 * CondGetArg -- 167 * Find the argument of a built-in function. parens is set to TRUE 168 * if the arguments are bounded by parens. 169 * 170 * Results: 171 * The length of the argument and the address of the argument. 172 * 173 * Side Effects: 174 * The pointer is set to point to the closing parenthesis of the 175 * function call. 176 * 177 *----------------------------------------------------------------------- 178 */ 179static int 180CondGetArg(char **linePtr, char **argPtr, char *func, Boolean parens) 181{ 182 char *cp; 183 int argLen; 184 Buffer buf; 185 186 cp = *linePtr; 187 if (parens) { 188 while (*cp != '(' && *cp != '\0') { 189 cp++; 190 } 191 if (*cp == '(') { 192 cp++; 193 } 194 } 195 196 if (*cp == '\0') { 197 /* 198 * No arguments whatsoever. Because 'make' and 'defined' aren't really 199 * "reserved words", we don't print a message. I think this is better 200 * than hitting the user with a warning message every time s/he uses 201 * the word 'make' or 'defined' at the beginning of a symbol... 202 */ 203 *argPtr = cp; 204 return (0); 205 } 206 207 while (*cp == ' ' || *cp == '\t') { 208 cp++; 209 } 210 211 /* 212 * Create a buffer for the argument and start it out at 16 characters 213 * long. Why 16? Why not? 214 */ 215 buf = Buf_Init(16); 216 217 while ((strchr(" \t)&|", *cp) == NULL) && (*cp != '\0')) { 218 if (*cp == '$') { 219 /* 220 * Parse the variable spec and install it as part of the argument 221 * if it's valid. We tell Var_Parse to complain on an undefined 222 * variable, so we don't do it too. Nor do we return an error, 223 * though perhaps we should... 224 */ 225 char *cp2; 226 int len; 227 Boolean doFree; 228 229 cp2 = Var_Parse(cp, VAR_CMD, TRUE, &len, &doFree); 230 231 Buf_AddBytes(buf, strlen(cp2), (Byte *)cp2); 232 if (doFree) { 233 free(cp2); 234 } 235 cp += len; 236 } else { 237 Buf_AddByte(buf, (Byte)*cp); 238 cp++; 239 } 240 } 241 242 Buf_AddByte(buf, (Byte)'\0'); 243 *argPtr = (char *)Buf_GetAll(buf, &argLen); 244 Buf_Destroy(buf, FALSE); 245 246 while (*cp == ' ' || *cp == '\t') { 247 cp++; 248 } 249 if (parens && *cp != ')') { 250 Parse_Error(PARSE_WARNING, "Missing closing parenthesis for %s()", 251 func); 252 return (0); 253 } else if (parens) { 254 /* 255 * Advance pointer past close parenthesis. 256 */ 257 cp++; 258 } 259 260 *linePtr = cp; 261 return (argLen); 262} 263 264/*- 265 *----------------------------------------------------------------------- 266 * CondDoDefined -- 267 * Handle the 'defined' function for conditionals. 268 * 269 * Results: 270 * TRUE if the given variable is defined. 271 * 272 * Side Effects: 273 * None. 274 * 275 *----------------------------------------------------------------------- 276 */ 277static Boolean 278CondDoDefined(int argLen, char *arg) 279{ 280 char savec = arg[argLen]; 281 char *p1; 282 Boolean result; 283 284 arg[argLen] = '\0'; 285 if (Var_Value(arg, VAR_CMD, &p1) != NULL) { 286 result = TRUE; 287 } else { 288 result = FALSE; 289 } 290 free(p1); 291 arg[argLen] = savec; 292 return (result); 293} 294 295/*- 296 *----------------------------------------------------------------------- 297 * CondStrMatch -- 298 * Front-end for Str_Match so it returns 0 on match and non-zero 299 * on mismatch. Callback function for CondDoMake via Lst_Find 300 * 301 * Results: 302 * 0 if string matches pattern 303 * 304 * Side Effects: 305 * None 306 * 307 *----------------------------------------------------------------------- 308 */ 309static int 310CondStrMatch(void *string, void *pattern) 311{ 312 313 return (!Str_Match((char *)string, (char *)pattern)); 314} 315 316/*- 317 *----------------------------------------------------------------------- 318 * CondDoMake -- 319 * Handle the 'make' function for conditionals. 320 * 321 * Results: 322 * TRUE if the given target is being made. 323 * 324 * Side Effects: 325 * None. 326 * 327 *----------------------------------------------------------------------- 328 */ 329static Boolean 330CondDoMake(int argLen, char *arg) 331{ 332 char savec = arg[argLen]; 333 Boolean result; 334 335 arg[argLen] = '\0'; 336 if (Lst_Find(create, arg, CondStrMatch) == NULL) { 337 result = FALSE; 338 } else { 339 result = TRUE; 340 } 341 arg[argLen] = savec; 342 return (result); 343} 344 345/*- 346 *----------------------------------------------------------------------- 347 * CondDoExists -- 348 * See if the given file exists. 349 * 350 * Results: 351 * TRUE if the file exists and FALSE if it does not. 352 * 353 * Side Effects: 354 * None. 355 * 356 *----------------------------------------------------------------------- 357 */ 358static Boolean 359CondDoExists(int argLen, char *arg) 360{ 361 char savec = arg[argLen]; 362 Boolean result; 363 char *path; 364 365 arg[argLen] = '\0'; 366 path = Dir_FindFile(arg, dirSearchPath); 367 if (path != NULL) { 368 result = TRUE; 369 free(path); 370 } else { 371 result = FALSE; 372 } 373 arg[argLen] = savec; 374 return (result); 375} 376 377/*- 378 *----------------------------------------------------------------------- 379 * CondDoTarget -- 380 * See if the given node exists and is an actual target. 381 * 382 * Results: 383 * TRUE if the node exists as a target and FALSE if it does not. 384 * 385 * Side Effects: 386 * None. 387 * 388 *----------------------------------------------------------------------- 389 */ 390static Boolean 391CondDoTarget(int argLen, char *arg) 392{ 393 char savec = arg[argLen]; 394 Boolean result; 395 GNode *gn; 396 397 arg[argLen] = '\0'; 398 gn = Targ_FindNode(arg, TARG_NOCREATE); 399 if ((gn != NULL) && !OP_NOP(gn->type)) { 400 result = TRUE; 401 } else { 402 result = FALSE; 403 } 404 arg[argLen] = savec; 405 return (result); 406} 407 408/*- 409 *----------------------------------------------------------------------- 410 * CondCvtArg -- 411 * Convert the given number into a double. If the number begins 412 * with 0x, it is interpreted as a hexadecimal integer 413 * and converted to a double from there. All other strings just have 414 * strtod called on them. 415 * 416 * Results: 417 * Sets 'value' to double value of string. 418 * Returns address of the first character after the last valid 419 * character of the converted number. 420 * 421 * Side Effects: 422 * Can change 'value' even if string is not a valid number. 423 * 424 * 425 *----------------------------------------------------------------------- 426 */ 427static char * 428CondCvtArg(char *str, double *value) 429{ 430 if ((*str == '0') && (str[1] == 'x')) { 431 long i; 432 433 for (str += 2, i = 0; ; str++) { 434 int x; 435 if (isdigit((unsigned char)*str)) 436 x = *str - '0'; 437 else if (isxdigit((unsigned char)*str)) 438 x = 10 + *str - isupper((unsigned char)*str) ? 'A' : 'a'; 439 else { 440 *value = (double)i; 441 return (str); 442 } 443 i = (i << 4) + x; 444 } 445 } 446 else { 447 char *eptr; 448 *value = strtod(str, &eptr); 449 return (eptr); 450 } 451} 452 453/*- 454 *----------------------------------------------------------------------- 455 * CondToken -- 456 * Return the next token from the input. 457 * 458 * Results: 459 * A Token for the next lexical token in the stream. 460 * 461 * Side Effects: 462 * condPushback will be set back to None if it is used. 463 * 464 *----------------------------------------------------------------------- 465 */ 466static Token 467CondToken(Boolean doEval) 468{ 469 Token t; 470 471 if (condPushBack == None) { 472 while (*condExpr == ' ' || *condExpr == '\t') { 473 condExpr++; 474 } 475 switch (*condExpr) { 476 case '(': 477 t = LParen; 478 condExpr++; 479 break; 480 case ')': 481 t = RParen; 482 condExpr++; 483 break; 484 case '|': 485 if (condExpr[1] == '|') { 486 condExpr++; 487 } 488 condExpr++; 489 t = Or; 490 break; 491 case '&': 492 if (condExpr[1] == '&') { 493 condExpr++; 494 } 495 condExpr++; 496 t = And; 497 break; 498 case '!': 499 t = Not; 500 condExpr++; 501 break; 502 case '\n': 503 case '\0': 504 t = EndOfFile; 505 break; 506 case '$': { 507 char *lhs; 508 char *rhs; 509 char *op; 510 int varSpecLen; 511 Boolean doFree; 512 513 /* 514 * Parse the variable spec and skip over it, saving its 515 * value in lhs. 516 */ 517 t = Err; 518 lhs = Var_Parse(condExpr, VAR_CMD, doEval, 519 &varSpecLen, &doFree); 520 if (lhs == var_Error) { 521 /* 522 * Even if !doEval, we still report syntax errors, which 523 * is what getting var_Error back with !doEval means. 524 */ 525 return (Err); 526 } 527 condExpr += varSpecLen; 528 529 if (!isspace((unsigned char)*condExpr) && 530 strchr("!=><", *condExpr) == NULL) { 531 Buffer buf; 532 char *cp; 533 534 buf = Buf_Init(0); 535 536 for (cp = lhs; *cp; cp++) 537 Buf_AddByte(buf, (Byte)*cp); 538 539 if (doFree) 540 free(lhs); 541 542 for (;*condExpr && !isspace((unsigned char) *condExpr); 543 condExpr++) 544 Buf_AddByte(buf, (Byte)*condExpr); 545 546 Buf_AddByte(buf, (Byte)'\0'); 547 lhs = (char *)Buf_GetAll(buf, &varSpecLen); 548 Buf_Destroy(buf, FALSE); 549 550 doFree = TRUE; 551 } 552 553 /* 554 * Skip whitespace to get to the operator 555 */ 556 while (isspace((unsigned char)*condExpr)) 557 condExpr++; 558 559 /* 560 * Make sure the operator is a valid one. If it isn't a 561 * known relational operator, pretend we got a 562 * != 0 comparison. 563 */ 564 op = condExpr; 565 switch (*condExpr) { 566 case '!': 567 case '=': 568 case '<': 569 case '>': 570 if (condExpr[1] == '=') { 571 condExpr += 2; 572 } else { 573 condExpr += 1; 574 } 575 break; 576 default: 577 op = "!="; 578 rhs = "0"; 579 580 goto do_compare; 581 } 582 while (isspace((unsigned char)*condExpr)) { 583 condExpr++; 584 } 585 if (*condExpr == '\0') { 586 Parse_Error(PARSE_WARNING, 587 "Missing right-hand-side of operator"); 588 goto error; 589 } 590 rhs = condExpr; 591do_compare: 592 if (*rhs == '"') { 593 /* 594 * Doing a string comparison. Only allow == and != for 595 * operators. 596 */ 597 char *string; 598 char *cp, *cp2; 599 int qt; 600 Buffer buf; 601 602do_string_compare: 603 if (((*op != '!') && (*op != '=')) || (op[1] != '=')) { 604 Parse_Error(PARSE_WARNING, 605 "String comparison operator should be either == or !="); 606 goto error; 607 } 608 609 buf = Buf_Init(0); 610 qt = *rhs == '"' ? 1 : 0; 611 612 for (cp = &rhs[qt]; 613 ((qt && (*cp != '"')) || 614 (!qt && strchr(" \t)", *cp) == NULL)) && 615 (*cp != '\0'); cp++) { 616 if ((*cp == '\\') && (cp[1] != '\0')) { 617 /* 618 * Backslash escapes things -- skip over next 619 * character, if it exists. 620 */ 621 cp++; 622 Buf_AddByte(buf, (Byte)*cp); 623 } else if (*cp == '$') { 624 int len; 625 Boolean freeIt; 626 627 cp2 = Var_Parse(cp, VAR_CMD, doEval, &len, &freeIt); 628 if (cp2 != var_Error) { 629 Buf_AddBytes(buf, strlen(cp2), (Byte *)cp2); 630 if (freeIt) { 631 free(cp2); 632 } 633 cp += len - 1; 634 } else { 635 Buf_AddByte(buf, (Byte)*cp); 636 } 637 } else { 638 Buf_AddByte(buf, (Byte)*cp); 639 } 640 } 641 642 Buf_AddByte(buf, (Byte)0); 643 644 string = (char *)Buf_GetAll(buf, (int *)NULL); 645 Buf_Destroy(buf, FALSE); 646 647 DEBUGF(COND, ("lhs = \"%s\", rhs = \"%s\", op = %.2s\n", 648 lhs, string, op)); 649 /* 650 * Null-terminate rhs and perform the comparison. 651 * t is set to the result. 652 */ 653 if (*op == '=') { 654 t = strcmp(lhs, string) ? False : True; 655 } else { 656 t = strcmp(lhs, string) ? True : False; 657 } 658 free(string); 659 if (rhs == condExpr) { 660 if (!qt && *cp == ')') 661 condExpr = cp; 662 else 663 condExpr = cp + 1; 664 } 665 } else { 666 /* 667 * rhs is either a float or an integer. Convert both the 668 * lhs and the rhs to a double and compare the two. 669 */ 670 double left, right; 671 char *string; 672 673 if (*CondCvtArg(lhs, &left) != '\0') 674 goto do_string_compare; 675 if (*rhs == '$') { 676 int len; 677 Boolean freeIt; 678 679 string = Var_Parse(rhs, VAR_CMD, doEval, &len, &freeIt); 680 if (string == var_Error) { 681 right = 0.0; 682 } else { 683 if (*CondCvtArg(string, &right) != '\0') { 684 if (freeIt) 685 free(string); 686 goto do_string_compare; 687 } 688 if (freeIt) 689 free(string); 690 if (rhs == condExpr) 691 condExpr += len; 692 } 693 } else { 694 char *c = CondCvtArg(rhs, &right); 695 if (c == rhs) 696 goto do_string_compare; 697 if (rhs == condExpr) { 698 /* 699 * Skip over the right-hand side 700 */ 701 condExpr = c; 702 } 703 } 704 705 DEBUGF(COND, ("left = %f, right = %f, op = %.2s\n", left, 706 right, op)); 707 switch (op[0]) { 708 case '!': 709 if (op[1] != '=') { 710 Parse_Error(PARSE_WARNING, 711 "Unknown operator"); 712 goto error; 713 } 714 t = (left != right ? True : False); 715 break; 716 case '=': 717 if (op[1] != '=') { 718 Parse_Error(PARSE_WARNING, 719 "Unknown operator"); 720 goto error; 721 } 722 t = (left == right ? True : False); 723 break; 724 case '<': 725 if (op[1] == '=') { 726 t = (left <= right ? True : False); 727 } else { 728 t = (left < right ? True : False); 729 } 730 break; 731 case '>': 732 if (op[1] == '=') { 733 t = (left >= right ? True : False); 734 } else { 735 t = (left > right ? True : False); 736 } 737 break; 738 default: 739 break; 740 } 741 } 742error: 743 if (doFree) 744 free(lhs); 745 break; 746 } 747 default: { 748 Boolean (*evalProc)(int, char *); 749 Boolean invert = FALSE; 750 char *arg; 751 int arglen; 752 753 if (strncmp(condExpr, "defined", 7) == 0) { 754 /* 755 * Use CondDoDefined to evaluate the argument and 756 * CondGetArg to extract the argument from the 'function 757 * call'. 758 */ 759 evalProc = CondDoDefined; 760 condExpr += 7; 761 arglen = CondGetArg(&condExpr, &arg, "defined", TRUE); 762 if (arglen == 0) { 763 condExpr -= 7; 764 goto use_default; 765 } 766 } else if (strncmp(condExpr, "make", 4) == 0) { 767 /* 768 * Use CondDoMake to evaluate the argument and 769 * CondGetArg to extract the argument from the 'function 770 * call'. 771 */ 772 evalProc = CondDoMake; 773 condExpr += 4; 774 arglen = CondGetArg(&condExpr, &arg, "make", TRUE); 775 if (arglen == 0) { 776 condExpr -= 4; 777 goto use_default; 778 } 779 } else if (strncmp(condExpr, "exists", 6) == 0) { 780 /* 781 * Use CondDoExists to evaluate the argument and 782 * CondGetArg to extract the argument from the 783 * 'function call'. 784 */ 785 evalProc = CondDoExists; 786 condExpr += 6; 787 arglen = CondGetArg(&condExpr, &arg, "exists", TRUE); 788 if (arglen == 0) { 789 condExpr -= 6; 790 goto use_default; 791 } 792 } else if (strncmp(condExpr, "empty", 5) == 0) { 793 /* 794 * Use Var_Parse to parse the spec in parens and return 795 * True if the resulting string is empty. 796 */ 797 int length; 798 Boolean doFree; 799 char *val; 800 801 condExpr += 5; 802 803 for (arglen = 0; 804 condExpr[arglen] != '(' && condExpr[arglen] != '\0'; 805 arglen += 1) 806 continue; 807 808 if (condExpr[arglen] != '\0') { 809 val = Var_Parse(&condExpr[arglen - 1], VAR_CMD, 810 FALSE, &length, &doFree); 811 if (val == var_Error) { 812 t = Err; 813 } else { 814 /* 815 * A variable is empty when it just contains 816 * spaces... 4/15/92, christos 817 */ 818 char *p; 819 for (p = val; *p && isspace((unsigned char)*p); p++) 820 continue; 821 t = (*p == '\0') ? True : False; 822 } 823 if (doFree) { 824 free(val); 825 } 826 /* 827 * Advance condExpr to beyond the closing ). Note that 828 * we subtract one from arglen + length b/c length 829 * is calculated from condExpr[arglen - 1]. 830 */ 831 condExpr += arglen + length - 1; 832 } else { 833 condExpr -= 5; 834 goto use_default; 835 } 836 break; 837 } else if (strncmp(condExpr, "target", 6) == 0) { 838 /* 839 * Use CondDoTarget to evaluate the argument and 840 * CondGetArg to extract the argument from the 841 * 'function call'. 842 */ 843 evalProc = CondDoTarget; 844 condExpr += 6; 845 arglen = CondGetArg(&condExpr, &arg, "target", TRUE); 846 if (arglen == 0) { 847 condExpr -= 6; 848 goto use_default; 849 } 850 } else { 851 /* 852 * The symbol is itself the argument to the default 853 * function. We advance condExpr to the end of the symbol 854 * by hand (the next whitespace, closing paren or 855 * binary operator) and set to invert the evaluation 856 * function if condInvert is TRUE. 857 */ 858 use_default: 859 invert = condInvert; 860 evalProc = condDefProc; 861 arglen = CondGetArg(&condExpr, &arg, "", FALSE); 862 } 863 864 /* 865 * Evaluate the argument using the set function. If invert 866 * is TRUE, we invert the sense of the function. 867 */ 868 t = (!doEval || (* evalProc) (arglen, arg) ? 869 (invert ? False : True) : 870 (invert ? True : False)); 871 free(arg); 872 break; 873 } 874 } 875 } else { 876 t = condPushBack; 877 condPushBack = None; 878 } 879 return (t); 880} 881 882/*- 883 *----------------------------------------------------------------------- 884 * CondT -- 885 * Parse a single term in the expression. This consists of a terminal 886 * symbol or Not and a terminal symbol (not including the binary 887 * operators): 888 * T -> defined(variable) | make(target) | exists(file) | symbol 889 * T -> ! T | ( E ) 890 * 891 * Results: 892 * True, False or Err. 893 * 894 * Side Effects: 895 * Tokens are consumed. 896 * 897 *----------------------------------------------------------------------- 898 */ 899static Token 900CondT(Boolean doEval) 901{ 902 Token t; 903 904 t = CondToken(doEval); 905 906 if (t == EndOfFile) { 907 /* 908 * If we reached the end of the expression, the expression 909 * is malformed... 910 */ 911 t = Err; 912 } else if (t == LParen) { 913 /* 914 * T -> ( E ) 915 */ 916 t = CondE(doEval); 917 if (t != Err) { 918 if (CondToken(doEval) != RParen) { 919 t = Err; 920 } 921 } 922 } else if (t == Not) { 923 t = CondT(doEval); 924 if (t == True) { 925 t = False; 926 } else if (t == False) { 927 t = True; 928 } 929 } 930 return (t); 931} 932 933/*- 934 *----------------------------------------------------------------------- 935 * CondF -- 936 * Parse a conjunctive factor (nice name, wot?) 937 * F -> T && F | T 938 * 939 * Results: 940 * True, False or Err 941 * 942 * Side Effects: 943 * Tokens are consumed. 944 * 945 *----------------------------------------------------------------------- 946 */ 947static Token 948CondF(Boolean doEval) 949{ 950 Token l, o; 951 952 l = CondT(doEval); 953 if (l != Err) { 954 o = CondToken(doEval); 955 956 if (o == And) { 957 /* 958 * F -> T && F 959 * 960 * If T is False, the whole thing will be False, but we have to 961 * parse the r.h.s. anyway (to throw it away). 962 * If T is True, the result is the r.h.s., be it an Err or no. 963 */ 964 if (l == True) { 965 l = CondF(doEval); 966 } else { 967 CondF(FALSE); 968 } 969 } else { 970 /* 971 * F -> T 972 */ 973 CondPushBack(o); 974 } 975 } 976 return (l); 977} 978 979/*- 980 *----------------------------------------------------------------------- 981 * CondE -- 982 * Main expression production. 983 * E -> F || E | F 984 * 985 * Results: 986 * True, False or Err. 987 * 988 * Side Effects: 989 * Tokens are, of course, consumed. 990 * 991 *----------------------------------------------------------------------- 992 */ 993static Token 994CondE(Boolean doEval) 995{ 996 Token l, o; 997 998 l = CondF(doEval); 999 if (l != Err) { 1000 o = CondToken(doEval); 1001 1002 if (o == Or) { 1003 /* 1004 * E -> F || E 1005 * 1006 * A similar thing occurs for ||, except that here we make sure 1007 * the l.h.s. is False before we bother to evaluate the r.h.s. 1008 * Once again, if l is False, the result is the r.h.s. and once 1009 * again if l is True, we parse the r.h.s. to throw it away. 1010 */ 1011 if (l == False) { 1012 l = CondE(doEval); 1013 } else { 1014 CondE(FALSE); 1015 } 1016 } else { 1017 /* 1018 * E -> F 1019 */ 1020 CondPushBack(o); 1021 } 1022 } 1023 return (l); 1024} 1025 1026/*- 1027 *----------------------------------------------------------------------- 1028 * Cond_Eval -- 1029 * Evaluate the conditional in the passed line. The line 1030 * looks like this: 1031 * #<cond-type> <expr> 1032 * where <cond-type> is any of if, ifmake, ifnmake, ifdef, 1033 * ifndef, elif, elifmake, elifnmake, elifdef, elifndef 1034 * and <expr> consists of &&, ||, !, make(target), defined(variable) 1035 * and parenthetical groupings thereof. 1036 * 1037 * Results: 1038 * COND_PARSE if should parse lines after the conditional 1039 * COND_SKIP if should skip lines after the conditional 1040 * COND_INVALID if not a valid conditional. 1041 * 1042 * Side Effects: 1043 * None. 1044 * 1045 *----------------------------------------------------------------------- 1046 */ 1047int 1048Cond_Eval(char *line) 1049{ 1050 struct If *ifp; 1051 Boolean isElse; 1052 Boolean value = FALSE; 1053 int level; /* Level at which to report errors. */ 1054 int lineno; 1055 1056 level = PARSE_FATAL; 1057 lineno = curFile.lineno; 1058 1059 for (line++; *line == ' ' || *line == '\t'; line++) { 1060 continue; 1061 } 1062 1063 /* 1064 * Find what type of if we're dealing with. The result is left 1065 * in ifp and isElse is set TRUE if it's an elif line. 1066 */ 1067 if (line[0] == 'e' && line[1] == 'l') { 1068 line += 2; 1069 isElse = TRUE; 1070 } else if (strncmp(line, "endif", 5) == 0) { 1071 /* 1072 * End of a conditional section. If skipIfLevel is non-zero, that 1073 * conditional was skipped, so lines following it should also be 1074 * skipped. Hence, we return COND_SKIP. Otherwise, the conditional 1075 * was read so succeeding lines should be parsed (think about it...) 1076 * so we return COND_PARSE, unless this endif isn't paired with 1077 * a decent if. 1078 */ 1079 if (skipIfLevel != 0) { 1080 skipIfLevel -= 1; 1081 return (COND_SKIP); 1082 } else { 1083 if (condTop == MAXIF) { 1084 Parse_Error(level, "if-less endif"); 1085 return (COND_INVALID); 1086 } else { 1087 skipLine = FALSE; 1088 condTop += 1; 1089 return (COND_PARSE); 1090 } 1091 } 1092 } else { 1093 isElse = FALSE; 1094 } 1095 1096 /* 1097 * Figure out what sort of conditional it is -- what its default 1098 * function is, etc. -- by looking in the table of valid "ifs" 1099 */ 1100 for (ifp = ifs; ifp->form != NULL; ifp++) { 1101 if (strncmp(ifp->form, line, ifp->formlen) == 0) { 1102 break; 1103 } 1104 } 1105 1106 if (ifp->form == NULL) { 1107 /* 1108 * Nothing fit. If the first word on the line is actually 1109 * "else", it's a valid conditional whose value is the inverse 1110 * of the previous if we parsed. 1111 */ 1112 if (isElse && (line[0] == 's') && (line[1] == 'e')) { 1113 if (condTop == MAXIF) { 1114 Parse_Error(level, "if-less else"); 1115 return (COND_INVALID); 1116 } else if (skipIfLevel == 0) { 1117 value = !condStack[condTop]; 1118 lineno = condLineno[condTop]; 1119 } else { 1120 return (COND_SKIP); 1121 } 1122 } else { 1123 /* 1124 * Not a valid conditional type. No error... 1125 */ 1126 return (COND_INVALID); 1127 } 1128 } else { 1129 if (isElse) { 1130 if (condTop == MAXIF) { 1131 Parse_Error(level, "if-less elif"); 1132 return (COND_INVALID); 1133 } else if (skipIfLevel != 0) { 1134 /* 1135 * If skipping this conditional, just ignore the whole thing. 1136 * If we don't, the user might be employing a variable that's 1137 * undefined, for which there's an enclosing ifdef that 1138 * we're skipping... 1139 */ 1140 skipIfLineno[skipIfLevel - 1] = lineno; 1141 return (COND_SKIP); 1142 } 1143 } else if (skipLine) { 1144 /* 1145 * Don't even try to evaluate a conditional that's not an else if 1146 * we're skipping things... 1147 */ 1148 skipIfLineno[skipIfLevel] = lineno; 1149 skipIfLevel += 1; 1150 return (COND_SKIP); 1151 } 1152 1153 /* 1154 * Initialize file-global variables for parsing 1155 */ 1156 condDefProc = ifp->defProc; 1157 condInvert = ifp->doNot; 1158 1159 line += ifp->formlen; 1160 1161 while (*line == ' ' || *line == '\t') { 1162 line++; 1163 } 1164 1165 condExpr = line; 1166 condPushBack = None; 1167 1168 switch (CondE(TRUE)) { 1169 case True: 1170 if (CondToken(TRUE) == EndOfFile) { 1171 value = TRUE; 1172 break; 1173 } 1174 goto err; 1175 /*FALLTHRU*/ 1176 case False: 1177 if (CondToken(TRUE) == EndOfFile) { 1178 value = FALSE; 1179 break; 1180 } 1181 /*FALLTHRU*/ 1182 case Err: 1183 err: 1184 Parse_Error(level, "Malformed conditional (%s)", 1185 line); 1186 return (COND_INVALID); 1187 default: 1188 break; 1189 } 1190 } 1191 if (!isElse) { 1192 condTop -= 1; 1193 } else if ((skipIfLevel != 0) || condStack[condTop]) { 1194 /* 1195 * If this is an else-type conditional, it should only take effect 1196 * if its corresponding if was evaluated and FALSE. If its if was 1197 * TRUE or skipped, we return COND_SKIP (and start skipping in case 1198 * we weren't already), leaving the stack unmolested so later elif's 1199 * don't screw up... 1200 */ 1201 skipLine = TRUE; 1202 return (COND_SKIP); 1203 } 1204 1205 if (condTop < 0) { 1206 /* 1207 * This is the one case where we can definitely proclaim a fatal 1208 * error. If we don't, we're hosed. 1209 */ 1210 Parse_Error(PARSE_FATAL, "Too many nested if's. %d max.", MAXIF); 1211 return (COND_INVALID); 1212 } else { 1213 condStack[condTop] = value; 1214 condLineno[condTop] = lineno; 1215 skipLine = !value; 1216 return (value ? COND_PARSE : COND_SKIP); 1217 } 1218} 1219 1220/*- 1221 *----------------------------------------------------------------------- 1222 * Cond_End -- 1223 * Make sure everything's clean at the end of a makefile. 1224 * 1225 * Results: 1226 * None. 1227 * 1228 * Side Effects: 1229 * Parse_Error will be called if open conditionals are around. 1230 * 1231 *----------------------------------------------------------------------- 1232 */ 1233void 1234Cond_End(void) 1235{ 1236 int level; 1237 1238 if (condTop != MAXIF) { 1239 Parse_Error(PARSE_FATAL, "%d open conditional%s:", 1240 MAXIF - condTop + skipIfLevel, 1241 MAXIF - condTop + skipIfLevel== 1 ? "" : "s"); 1242 1243 for (level = skipIfLevel; level > 0; level--) 1244 Parse_Error(PARSE_FATAL, "\t%*sat line %d (skipped)", 1245 MAXIF - condTop + level + 1, "", skipIfLineno[level - 1]); 1246 for (level = condTop; level < MAXIF; level++) 1247 Parse_Error(PARSE_FATAL, "\t%*sat line %d " 1248 "(evaluated to %s)", MAXIF - level + skipIfLevel, "", 1249 condLineno[level], condStack[level] ? "true" : "false"); 1250 } 1251 condTop = MAXIF; 1252} 1253