cond.c revision 143959
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 143959 2005-03-22 07:50:40Z 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 <string.h> 56#include <stdlib.h> 57 58#include "buf.h" 59#include "cond.h" 60#include "dir.h" 61#include "globals.h" 62#include "GNode.h" 63#include "make.h" 64#include "parse.h" 65#include "sprite.h" 66#include "str.h" 67#include "targ.h" 68#include "util.h" 69#include "var.h" 70 71/* 72 * The parsing of conditional expressions is based on this grammar: 73 * E -> F || E 74 * E -> F 75 * F -> T && F 76 * F -> T 77 * T -> defined(variable) 78 * T -> make(target) 79 * T -> exists(file) 80 * T -> empty(varspec) 81 * T -> target(name) 82 * T -> symbol 83 * T -> $(varspec) op value 84 * T -> $(varspec) == "string" 85 * T -> $(varspec) != "string" 86 * T -> ( E ) 87 * T -> ! T 88 * op -> == | != | > | < | >= | <= 89 * 90 * 'symbol' is some other symbol to which the default function (condDefProc) 91 * is applied. 92 * 93 * Tokens are scanned from the 'condExpr' string. The scanner (CondToken) 94 * will return And for '&' and '&&', Or for '|' and '||', Not for '!', 95 * LParen for '(', RParen for ')' and will evaluate the other terminal 96 * symbols, using either the default function or the function given in the 97 * terminal, and return the result as either True or False. 98 * 99 * All Non-Terminal functions (CondE, CondF and CondT) return Err on error. 100 */ 101typedef enum { 102 And, Or, Not, True, False, LParen, RParen, EndOfFile, None, Err 103} Token; 104 105typedef Boolean CondProc(int, char *); 106 107/*- 108 * Structures to handle elegantly the different forms of #if's. The 109 * last two fields are stored in condInvert and condDefProc, respectively. 110 */ 111static void CondPushBack(Token); 112static int CondGetArg(char **, char **, const char *, Boolean); 113static CondProc CondDoDefined; 114static CondProc CondDoMake; 115static CondProc CondDoExists; 116static CondProc CondDoTarget; 117static char *CondCvtArg(char *, double *); 118static Token CondToken(Boolean); 119static Token CondT(Boolean); 120static Token CondF(Boolean); 121static Token CondE(Boolean); 122 123static struct If { 124 char *form; /* Form of if */ 125 int formlen; /* Length of form */ 126 Boolean doNot; /* TRUE if default function should be negated */ 127 CondProc *defProc; /* Default function to apply */ 128} ifs[] = { 129 { "ifdef", 5, FALSE, CondDoDefined }, 130 { "ifndef", 6, TRUE, CondDoDefined }, 131 { "ifmake", 6, FALSE, CondDoMake }, 132 { "ifnmake", 7, TRUE, CondDoMake }, 133 { "if", 2, FALSE, CondDoDefined }, 134 { NULL, 0, FALSE, NULL } 135}; 136 137static Boolean condInvert; /* Invert the default function */ 138static Boolean (*condDefProc) /* Default function to apply */ 139(int, char *); 140static char *condExpr; /* The expression to parse */ 141static Token condPushBack=None; /* Single push-back token used in 142 * parsing */ 143 144#define MAXIF 30 /* greatest depth of #if'ing */ 145 146static Boolean condStack[MAXIF]; /* Stack of conditionals's values */ 147static int condLineno[MAXIF]; /* Line numbers of the opening .if */ 148static int condTop = MAXIF; /* Top-most conditional */ 149static int skipIfLevel=0; /* Depth of skipped conditionals */ 150static int skipIfLineno[MAXIF]; /* Line numbers of skipped .ifs */ 151static Boolean skipLine = FALSE; /* Whether the parse module is skipping 152 * lines */ 153 154/*- 155 *----------------------------------------------------------------------- 156 * CondPushBack -- 157 * Push back the most recent token read. We only need one level of 158 * this, so the thing is just stored in 'condPushback'. 159 * 160 * Results: 161 * None. 162 * 163 * Side Effects: 164 * condPushback is overwritten. 165 * 166 *----------------------------------------------------------------------- 167 */ 168static void 169CondPushBack(Token t) 170{ 171 172 condPushBack = t; 173} 174 175/*- 176 *----------------------------------------------------------------------- 177 * CondGetArg -- 178 * Find the argument of a built-in function. parens is set to TRUE 179 * if the arguments are bounded by parens. 180 * 181 * Results: 182 * The length of the argument and the address of the argument. 183 * 184 * Side Effects: 185 * The pointer is set to point to the closing parenthesis of the 186 * function call. 187 * 188 *----------------------------------------------------------------------- 189 */ 190static int 191CondGetArg(char **linePtr, char **argPtr, const char *func, Boolean parens) 192{ 193 char *cp; 194 size_t argLen; 195 Buffer *buf; 196 197 cp = *linePtr; 198 if (parens) { 199 while (*cp != '(' && *cp != '\0') { 200 cp++; 201 } 202 if (*cp == '(') { 203 cp++; 204 } 205 } 206 207 if (*cp == '\0') { 208 /* 209 * No arguments whatsoever. Because 'make' and 'defined' aren't really 210 * "reserved words", we don't print a message. I think this is better 211 * than hitting the user with a warning message every time s/he uses 212 * the word 'make' or 'defined' at the beginning of a symbol... 213 */ 214 *argPtr = cp; 215 return (0); 216 } 217 218 while (*cp == ' ' || *cp == '\t') { 219 cp++; 220 } 221 222 /* 223 * Create a buffer for the argument and start it out at 16 characters 224 * long. Why 16? Why not? 225 */ 226 buf = Buf_Init(16); 227 228 while ((strchr(" \t)&|", *cp) == NULL) && (*cp != '\0')) { 229 if (*cp == '$') { 230 /* 231 * Parse the variable spec and install it as part of the argument 232 * if it's valid. We tell Var_Parse to complain on an undefined 233 * variable, so we don't do it too. Nor do we return an error, 234 * though perhaps we should... 235 */ 236 char *cp2; 237 size_t len = 0; 238 Boolean doFree; 239 240 cp2 = Var_Parse(cp, VAR_CMD, TRUE, &len, &doFree); 241 242 Buf_Append(buf, cp2); 243 if (doFree) { 244 free(cp2); 245 } 246 cp += len; 247 } else { 248 Buf_AddByte(buf, (Byte)*cp); 249 cp++; 250 } 251 } 252 253 Buf_AddByte(buf, (Byte)'\0'); 254 *argPtr = (char *)Buf_GetAll(buf, &argLen); 255 Buf_Destroy(buf, FALSE); 256 257 while (*cp == ' ' || *cp == '\t') { 258 cp++; 259 } 260 if (parens && *cp != ')') { 261 Parse_Error(PARSE_WARNING, "Missing closing parenthesis for %s()", 262 func); 263 return (0); 264 } else if (parens) { 265 /* 266 * Advance pointer past close parenthesis. 267 */ 268 cp++; 269 } 270 271 *linePtr = cp; 272 return (argLen); 273} 274 275/*- 276 *----------------------------------------------------------------------- 277 * CondDoDefined -- 278 * Handle the 'defined' function for conditionals. 279 * 280 * Results: 281 * TRUE if the given variable is defined. 282 * 283 * Side Effects: 284 * None. 285 * 286 *----------------------------------------------------------------------- 287 */ 288static Boolean 289CondDoDefined(int argLen, char *arg) 290{ 291 char savec = arg[argLen]; 292 char *p1; 293 Boolean result; 294 295 arg[argLen] = '\0'; 296 if (Var_Value(arg, VAR_CMD, &p1) != NULL) { 297 result = TRUE; 298 } else { 299 result = FALSE; 300 } 301 free(p1); 302 arg[argLen] = savec; 303 return (result); 304} 305 306/*- 307 *----------------------------------------------------------------------- 308 * CondDoMake -- 309 * Handle the 'make' function for conditionals. 310 * 311 * Results: 312 * TRUE if the given target is being made. 313 * 314 * Side Effects: 315 * None. 316 * 317 *----------------------------------------------------------------------- 318 */ 319static Boolean 320CondDoMake(int argLen, char *arg) 321{ 322 char savec = arg[argLen]; 323 Boolean result; 324 const LstNode *ln; 325 326 arg[argLen] = '\0'; 327 result = FALSE; 328 LST_FOREACH(ln, &create) { 329 if (Str_Match(Lst_Datum(ln), arg)) { 330 result = TRUE; 331 break; 332 } 333 } 334 arg[argLen] = savec; 335 return (result); 336} 337 338/*- 339 *----------------------------------------------------------------------- 340 * CondDoExists -- 341 * See if the given file exists. 342 * 343 * Results: 344 * TRUE if the file exists and FALSE if it does not. 345 * 346 * Side Effects: 347 * None. 348 * 349 *----------------------------------------------------------------------- 350 */ 351static Boolean 352CondDoExists(int argLen, char *arg) 353{ 354 char savec = arg[argLen]; 355 Boolean result; 356 char *path; 357 358 arg[argLen] = '\0'; 359 path = Dir_FindFile(arg, &dirSearchPath); 360 if (path != NULL) { 361 result = TRUE; 362 free(path); 363 } else { 364 result = FALSE; 365 } 366 arg[argLen] = savec; 367 return (result); 368} 369 370/*- 371 *----------------------------------------------------------------------- 372 * CondDoTarget -- 373 * See if the given node exists and is an actual target. 374 * 375 * Results: 376 * TRUE if the node exists as a target and FALSE if it does not. 377 * 378 * Side Effects: 379 * None. 380 * 381 *----------------------------------------------------------------------- 382 */ 383static Boolean 384CondDoTarget(int argLen, char *arg) 385{ 386 char savec = arg[argLen]; 387 Boolean result; 388 GNode *gn; 389 390 arg[argLen] = '\0'; 391 gn = Targ_FindNode(arg, TARG_NOCREATE); 392 if ((gn != NULL) && !OP_NOP(gn->type)) { 393 result = TRUE; 394 } else { 395 result = FALSE; 396 } 397 arg[argLen] = savec; 398 return (result); 399} 400 401/*- 402 *----------------------------------------------------------------------- 403 * CondCvtArg -- 404 * Convert the given number into a double. If the number begins 405 * with 0x, it is interpreted as a hexadecimal integer 406 * and converted to a double from there. All other strings just have 407 * strtod called on them. 408 * 409 * Results: 410 * Sets 'value' to double value of string. 411 * Returns address of the first character after the last valid 412 * character of the converted number. 413 * 414 * Side Effects: 415 * Can change 'value' even if string is not a valid number. 416 * 417 * 418 *----------------------------------------------------------------------- 419 */ 420static char * 421CondCvtArg(char *str, double *value) 422{ 423 if ((*str == '0') && (str[1] == 'x')) { 424 long i; 425 426 for (str += 2, i = 0; ; str++) { 427 int x; 428 if (isdigit((unsigned char)*str)) 429 x = *str - '0'; 430 else if (isxdigit((unsigned char)*str)) 431 x = 10 + *str - isupper((unsigned char)*str) ? 'A' : 'a'; 432 else { 433 *value = (double)i; 434 return (str); 435 } 436 i = (i << 4) + x; 437 } 438 } 439 else { 440 char *eptr; 441 *value = strtod(str, &eptr); 442 return (eptr); 443 } 444} 445 446/*- 447 *----------------------------------------------------------------------- 448 * CondToken -- 449 * Return the next token from the input. 450 * 451 * Results: 452 * A Token for the next lexical token in the stream. 453 * 454 * Side Effects: 455 * condPushback will be set back to None if it is used. 456 * 457 *----------------------------------------------------------------------- 458 */ 459static Token 460CondToken(Boolean doEval) 461{ 462 Token t; 463 464 if (condPushBack == None) { 465 while (*condExpr == ' ' || *condExpr == '\t') { 466 condExpr++; 467 } 468 switch (*condExpr) { 469 case '(': 470 t = LParen; 471 condExpr++; 472 break; 473 case ')': 474 t = RParen; 475 condExpr++; 476 break; 477 case '|': 478 if (condExpr[1] == '|') { 479 condExpr++; 480 } 481 condExpr++; 482 t = Or; 483 break; 484 case '&': 485 if (condExpr[1] == '&') { 486 condExpr++; 487 } 488 condExpr++; 489 t = And; 490 break; 491 case '!': 492 t = Not; 493 condExpr++; 494 break; 495 case '\n': 496 case '\0': 497 t = EndOfFile; 498 break; 499 case '$': { 500 char *lhs; 501 char *rhs; 502 const char *op; 503 size_t varSpecLen = 0; 504 Boolean doFree; 505 506 /* 507 * Parse the variable spec and skip over it, saving its 508 * value in lhs. 509 */ 510 t = Err; 511 lhs = Var_Parse(condExpr, VAR_CMD, doEval, 512 &varSpecLen, &doFree); 513 if (lhs == var_Error) { 514 /* 515 * Even if !doEval, we still report syntax errors, which 516 * is what getting var_Error back with !doEval means. 517 */ 518 return (Err); 519 } 520 condExpr += varSpecLen; 521 522 if (!isspace((unsigned char)*condExpr) && 523 strchr("!=><", *condExpr) == NULL) { 524 Buffer *buf; 525 526 buf = Buf_Init(0); 527 528 Buf_Append(buf, lhs); 529 530 if (doFree) 531 free(lhs); 532 533 for (;*condExpr && !isspace((unsigned char) *condExpr); 534 condExpr++) 535 Buf_AddByte(buf, (Byte)*condExpr); 536 537 Buf_AddByte(buf, (Byte)'\0'); 538 lhs = (char *)Buf_GetAll(buf, &varSpecLen); 539 Buf_Destroy(buf, FALSE); 540 541 doFree = TRUE; 542 } 543 544 /* 545 * Skip whitespace to get to the operator 546 */ 547 while (isspace((unsigned char)*condExpr)) 548 condExpr++; 549 550 /* 551 * Make sure the operator is a valid one. If it isn't a 552 * known relational operator, pretend we got a 553 * != 0 comparison. 554 */ 555 op = condExpr; 556 switch (*condExpr) { 557 case '!': 558 case '=': 559 case '<': 560 case '>': 561 if (condExpr[1] == '=') { 562 condExpr += 2; 563 } else { 564 condExpr += 1; 565 } 566 break; 567 default: 568 op = "!="; 569 rhs = "0"; 570 571 goto do_compare; 572 } 573 while (isspace((unsigned char)*condExpr)) { 574 condExpr++; 575 } 576 if (*condExpr == '\0') { 577 Parse_Error(PARSE_WARNING, 578 "Missing right-hand-side of operator"); 579 goto error; 580 } 581 rhs = condExpr; 582do_compare: 583 if (*rhs == '"') { 584 /* 585 * Doing a string comparison. Only allow == and != for 586 * operators. 587 */ 588 char *string; 589 char *cp, *cp2; 590 int qt; 591 Buffer *buf; 592 593do_string_compare: 594 if (((*op != '!') && (*op != '=')) || (op[1] != '=')) { 595 Parse_Error(PARSE_WARNING, 596 "String comparison operator should be either == or !="); 597 goto error; 598 } 599 600 buf = Buf_Init(0); 601 qt = *rhs == '"' ? 1 : 0; 602 603 for (cp = &rhs[qt]; 604 ((qt && (*cp != '"')) || 605 (!qt && strchr(" \t)", *cp) == NULL)) && 606 (*cp != '\0'); cp++) { 607 if ((*cp == '\\') && (cp[1] != '\0')) { 608 /* 609 * Backslash escapes things -- skip over next 610 * character, if it exists. 611 */ 612 cp++; 613 Buf_AddByte(buf, (Byte)*cp); 614 } else if (*cp == '$') { 615 size_t len = 0; 616 Boolean freeIt; 617 618 cp2 = Var_Parse(cp, VAR_CMD, doEval, &len, &freeIt); 619 if (cp2 != var_Error) { 620 Buf_Append(buf, cp2); 621 if (freeIt) { 622 free(cp2); 623 } 624 cp += len - 1; 625 } else { 626 Buf_AddByte(buf, (Byte)*cp); 627 } 628 } else { 629 Buf_AddByte(buf, (Byte)*cp); 630 } 631 } 632 633 string = Buf_Peel(buf); 634 635 DEBUGF(COND, ("lhs = \"%s\", rhs = \"%s\", op = %.2s\n", 636 lhs, string, op)); 637 /* 638 * Null-terminate rhs and perform the comparison. 639 * t is set to the result. 640 */ 641 if (*op == '=') { 642 t = strcmp(lhs, string) ? False : True; 643 } else { 644 t = strcmp(lhs, string) ? True : False; 645 } 646 free(string); 647 if (rhs == condExpr) { 648 if (!qt && *cp == ')') 649 condExpr = cp; 650 else 651 condExpr = cp + 1; 652 } 653 } else { 654 /* 655 * rhs is either a float or an integer. Convert both the 656 * lhs and the rhs to a double and compare the two. 657 */ 658 double left, right; 659 char *string; 660 661 if (*CondCvtArg(lhs, &left) != '\0') 662 goto do_string_compare; 663 if (*rhs == '$') { 664 size_t len = 0; 665 Boolean freeIt; 666 667 string = Var_Parse(rhs, VAR_CMD, doEval, &len, &freeIt); 668 if (string == var_Error) { 669 right = 0.0; 670 } else { 671 if (*CondCvtArg(string, &right) != '\0') { 672 if (freeIt) 673 free(string); 674 goto do_string_compare; 675 } 676 if (freeIt) 677 free(string); 678 if (rhs == condExpr) 679 condExpr += len; 680 } 681 } else { 682 char *c = CondCvtArg(rhs, &right); 683 if (c == rhs) 684 goto do_string_compare; 685 if (rhs == condExpr) { 686 /* 687 * Skip over the right-hand side 688 */ 689 condExpr = c; 690 } 691 } 692 693 DEBUGF(COND, ("left = %f, right = %f, op = %.2s\n", left, 694 right, op)); 695 switch (op[0]) { 696 case '!': 697 if (op[1] != '=') { 698 Parse_Error(PARSE_WARNING, 699 "Unknown operator"); 700 goto error; 701 } 702 t = (left != right ? True : False); 703 break; 704 case '=': 705 if (op[1] != '=') { 706 Parse_Error(PARSE_WARNING, 707 "Unknown operator"); 708 goto error; 709 } 710 t = (left == right ? True : False); 711 break; 712 case '<': 713 if (op[1] == '=') { 714 t = (left <= right ? True : False); 715 } else { 716 t = (left < right ? True : False); 717 } 718 break; 719 case '>': 720 if (op[1] == '=') { 721 t = (left >= right ? True : False); 722 } else { 723 t = (left > right ? True : False); 724 } 725 break; 726 default: 727 break; 728 } 729 } 730error: 731 if (doFree) 732 free(lhs); 733 break; 734 } 735 default: { 736 CondProc *evalProc; 737 Boolean invert = FALSE; 738 char *arg; 739 int arglen; 740 741 if (strncmp(condExpr, "defined", 7) == 0) { 742 /* 743 * Use CondDoDefined to evaluate the argument and 744 * CondGetArg to extract the argument from the 'function 745 * call'. 746 */ 747 evalProc = CondDoDefined; 748 condExpr += 7; 749 arglen = CondGetArg(&condExpr, &arg, "defined", TRUE); 750 if (arglen == 0) { 751 condExpr -= 7; 752 goto use_default; 753 } 754 } else if (strncmp(condExpr, "make", 4) == 0) { 755 /* 756 * Use CondDoMake to evaluate the argument and 757 * CondGetArg to extract the argument from the 'function 758 * call'. 759 */ 760 evalProc = CondDoMake; 761 condExpr += 4; 762 arglen = CondGetArg(&condExpr, &arg, "make", TRUE); 763 if (arglen == 0) { 764 condExpr -= 4; 765 goto use_default; 766 } 767 } else if (strncmp(condExpr, "exists", 6) == 0) { 768 /* 769 * Use CondDoExists to evaluate the argument and 770 * CondGetArg to extract the argument from the 771 * 'function call'. 772 */ 773 evalProc = CondDoExists; 774 condExpr += 6; 775 arglen = CondGetArg(&condExpr, &arg, "exists", TRUE); 776 if (arglen == 0) { 777 condExpr -= 6; 778 goto use_default; 779 } 780 } else if (strncmp(condExpr, "empty", 5) == 0) { 781 /* 782 * Use Var_Parse to parse the spec in parens and return 783 * True if the resulting string is empty. 784 */ 785 size_t length; 786 Boolean doFree; 787 char *val; 788 789 condExpr += 5; 790 791 for (arglen = 0; 792 condExpr[arglen] != '(' && condExpr[arglen] != '\0'; 793 arglen += 1) 794 continue; 795 796 if (condExpr[arglen] != '\0') { 797 length = 0; 798 val = Var_Parse(&condExpr[arglen - 1], VAR_CMD, 799 FALSE, &length, &doFree); 800 if (val == var_Error) { 801 t = Err; 802 } else { 803 /* 804 * A variable is empty when it just contains 805 * spaces... 4/15/92, christos 806 */ 807 char *p; 808 for (p = val; *p && isspace((unsigned char)*p); p++) 809 continue; 810 t = (*p == '\0') ? True : False; 811 } 812 if (doFree) { 813 free(val); 814 } 815 /* 816 * Advance condExpr to beyond the closing ). Note that 817 * we subtract one from arglen + length b/c length 818 * is calculated from condExpr[arglen - 1]. 819 */ 820 condExpr += arglen + length - 1; 821 } else { 822 condExpr -= 5; 823 goto use_default; 824 } 825 break; 826 } else if (strncmp(condExpr, "target", 6) == 0) { 827 /* 828 * Use CondDoTarget to evaluate the argument and 829 * CondGetArg to extract the argument from the 830 * 'function call'. 831 */ 832 evalProc = CondDoTarget; 833 condExpr += 6; 834 arglen = CondGetArg(&condExpr, &arg, "target", TRUE); 835 if (arglen == 0) { 836 condExpr -= 6; 837 goto use_default; 838 } 839 } else { 840 /* 841 * The symbol is itself the argument to the default 842 * function. We advance condExpr to the end of the symbol 843 * by hand (the next whitespace, closing paren or 844 * binary operator) and set to invert the evaluation 845 * function if condInvert is TRUE. 846 */ 847 use_default: 848 invert = condInvert; 849 evalProc = condDefProc; 850 arglen = CondGetArg(&condExpr, &arg, "", FALSE); 851 } 852 853 /* 854 * Evaluate the argument using the set function. If invert 855 * is TRUE, we invert the sense of the function. 856 */ 857 t = (!doEval || (* evalProc) (arglen, arg) ? 858 (invert ? False : True) : 859 (invert ? True : False)); 860 free(arg); 861 break; 862 } 863 } 864 } else { 865 t = condPushBack; 866 condPushBack = None; 867 } 868 return (t); 869} 870 871/*- 872 *----------------------------------------------------------------------- 873 * CondT -- 874 * Parse a single term in the expression. This consists of a terminal 875 * symbol or Not and a terminal symbol (not including the binary 876 * operators): 877 * T -> defined(variable) | make(target) | exists(file) | symbol 878 * T -> ! T | ( E ) 879 * 880 * Results: 881 * True, False or Err. 882 * 883 * Side Effects: 884 * Tokens are consumed. 885 * 886 *----------------------------------------------------------------------- 887 */ 888static Token 889CondT(Boolean doEval) 890{ 891 Token t; 892 893 t = CondToken(doEval); 894 895 if (t == EndOfFile) { 896 /* 897 * If we reached the end of the expression, the expression 898 * is malformed... 899 */ 900 t = Err; 901 } else if (t == LParen) { 902 /* 903 * T -> ( E ) 904 */ 905 t = CondE(doEval); 906 if (t != Err) { 907 if (CondToken(doEval) != RParen) { 908 t = Err; 909 } 910 } 911 } else if (t == Not) { 912 t = CondT(doEval); 913 if (t == True) { 914 t = False; 915 } else if (t == False) { 916 t = True; 917 } 918 } 919 return (t); 920} 921 922/*- 923 *----------------------------------------------------------------------- 924 * CondF -- 925 * Parse a conjunctive factor (nice name, wot?) 926 * F -> T && F | T 927 * 928 * Results: 929 * True, False or Err 930 * 931 * Side Effects: 932 * Tokens are consumed. 933 * 934 *----------------------------------------------------------------------- 935 */ 936static Token 937CondF(Boolean doEval) 938{ 939 Token l, o; 940 941 l = CondT(doEval); 942 if (l != Err) { 943 o = CondToken(doEval); 944 945 if (o == And) { 946 /* 947 * F -> T && F 948 * 949 * If T is False, the whole thing will be False, but we have to 950 * parse the r.h.s. anyway (to throw it away). 951 * If T is True, the result is the r.h.s., be it an Err or no. 952 */ 953 if (l == True) { 954 l = CondF(doEval); 955 } else { 956 CondF(FALSE); 957 } 958 } else { 959 /* 960 * F -> T 961 */ 962 CondPushBack(o); 963 } 964 } 965 return (l); 966} 967 968/*- 969 *----------------------------------------------------------------------- 970 * CondE -- 971 * Main expression production. 972 * E -> F || E | F 973 * 974 * Results: 975 * True, False or Err. 976 * 977 * Side Effects: 978 * Tokens are, of course, consumed. 979 * 980 *----------------------------------------------------------------------- 981 */ 982static Token 983CondE(Boolean doEval) 984{ 985 Token l, o; 986 987 l = CondF(doEval); 988 if (l != Err) { 989 o = CondToken(doEval); 990 991 if (o == Or) { 992 /* 993 * E -> F || E 994 * 995 * A similar thing occurs for ||, except that here we make sure 996 * the l.h.s. is False before we bother to evaluate the r.h.s. 997 * Once again, if l is False, the result is the r.h.s. and once 998 * again if l is True, we parse the r.h.s. to throw it away. 999 */ 1000 if (l == False) { 1001 l = CondE(doEval); 1002 } else { 1003 CondE(FALSE); 1004 } 1005 } else { 1006 /* 1007 * E -> F 1008 */ 1009 CondPushBack(o); 1010 } 1011 } 1012 return (l); 1013} 1014 1015/*- 1016 *----------------------------------------------------------------------- 1017 * Cond_Eval -- 1018 * Evaluate the conditional in the passed line. The line 1019 * looks like this: 1020 * #<cond-type> <expr> 1021 * where <cond-type> is any of if, ifmake, ifnmake, ifdef, 1022 * ifndef, elif, elifmake, elifnmake, elifdef, elifndef 1023 * and <expr> consists of &&, ||, !, make(target), defined(variable) 1024 * and parenthetical groupings thereof. 1025 * 1026 * Results: 1027 * COND_PARSE if should parse lines after the conditional 1028 * COND_SKIP if should skip lines after the conditional 1029 * COND_INVALID if not a valid conditional. 1030 * 1031 * Side Effects: 1032 * None. 1033 * 1034 *----------------------------------------------------------------------- 1035 */ 1036int 1037Cond_Eval(char *line) 1038{ 1039 struct If *ifp; 1040 Boolean isElse; 1041 Boolean value = FALSE; 1042 int level; /* Level at which to report errors. */ 1043 int lineno; 1044 1045 level = PARSE_FATAL; 1046 lineno = curFile.lineno; 1047 1048 for (line++; *line == ' ' || *line == '\t'; line++) { 1049 continue; 1050 } 1051 1052 /* 1053 * Find what type of if we're dealing with. The result is left 1054 * in ifp and isElse is set TRUE if it's an elif line. 1055 */ 1056 if (line[0] == 'e' && line[1] == 'l') { 1057 line += 2; 1058 isElse = TRUE; 1059 } else if (strncmp(line, "endif", 5) == 0) { 1060 /* 1061 * End of a conditional section. If skipIfLevel is non-zero, that 1062 * conditional was skipped, so lines following it should also be 1063 * skipped. Hence, we return COND_SKIP. Otherwise, the conditional 1064 * was read so succeeding lines should be parsed (think about it...) 1065 * so we return COND_PARSE, unless this endif isn't paired with 1066 * a decent if. 1067 */ 1068 if (skipIfLevel != 0) { 1069 skipIfLevel -= 1; 1070 return (COND_SKIP); 1071 } else { 1072 if (condTop == MAXIF) { 1073 Parse_Error(level, "if-less endif"); 1074 return (COND_INVALID); 1075 } else { 1076 skipLine = FALSE; 1077 condTop += 1; 1078 return (COND_PARSE); 1079 } 1080 } 1081 } else { 1082 isElse = FALSE; 1083 } 1084 1085 /* 1086 * Figure out what sort of conditional it is -- what its default 1087 * function is, etc. -- by looking in the table of valid "ifs" 1088 */ 1089 for (ifp = ifs; ifp->form != NULL; ifp++) { 1090 if (strncmp(ifp->form, line, ifp->formlen) == 0) { 1091 break; 1092 } 1093 } 1094 1095 if (ifp->form == NULL) { 1096 /* 1097 * Nothing fit. If the first word on the line is actually 1098 * "else", it's a valid conditional whose value is the inverse 1099 * of the previous if we parsed. 1100 */ 1101 if (isElse && (line[0] == 's') && (line[1] == 'e')) { 1102 if (condTop == MAXIF) { 1103 Parse_Error(level, "if-less else"); 1104 return (COND_INVALID); 1105 } else if (skipIfLevel == 0) { 1106 value = !condStack[condTop]; 1107 lineno = condLineno[condTop]; 1108 } else { 1109 return (COND_SKIP); 1110 } 1111 } else { 1112 /* 1113 * Not a valid conditional type. No error... 1114 */ 1115 return (COND_INVALID); 1116 } 1117 } else { 1118 if (isElse) { 1119 if (condTop == MAXIF) { 1120 Parse_Error(level, "if-less elif"); 1121 return (COND_INVALID); 1122 } else if (skipIfLevel != 0) { 1123 /* 1124 * If skipping this conditional, just ignore the whole thing. 1125 * If we don't, the user might be employing a variable that's 1126 * undefined, for which there's an enclosing ifdef that 1127 * we're skipping... 1128 */ 1129 skipIfLineno[skipIfLevel - 1] = lineno; 1130 return (COND_SKIP); 1131 } 1132 } else if (skipLine) { 1133 /* 1134 * Don't even try to evaluate a conditional that's not an else if 1135 * we're skipping things... 1136 */ 1137 skipIfLineno[skipIfLevel] = lineno; 1138 skipIfLevel += 1; 1139 return (COND_SKIP); 1140 } 1141 1142 /* 1143 * Initialize file-global variables for parsing 1144 */ 1145 condDefProc = ifp->defProc; 1146 condInvert = ifp->doNot; 1147 1148 line += ifp->formlen; 1149 1150 while (*line == ' ' || *line == '\t') { 1151 line++; 1152 } 1153 1154 condExpr = line; 1155 condPushBack = None; 1156 1157 switch (CondE(TRUE)) { 1158 case True: 1159 if (CondToken(TRUE) == EndOfFile) { 1160 value = TRUE; 1161 break; 1162 } 1163 goto err; 1164 /*FALLTHRU*/ 1165 case False: 1166 if (CondToken(TRUE) == EndOfFile) { 1167 value = FALSE; 1168 break; 1169 } 1170 /*FALLTHRU*/ 1171 case Err: 1172 err: 1173 Parse_Error(level, "Malformed conditional (%s)", 1174 line); 1175 return (COND_INVALID); 1176 default: 1177 break; 1178 } 1179 } 1180 if (!isElse) { 1181 condTop -= 1; 1182 } else if ((skipIfLevel != 0) || condStack[condTop]) { 1183 /* 1184 * If this is an else-type conditional, it should only take effect 1185 * if its corresponding if was evaluated and FALSE. If its if was 1186 * TRUE or skipped, we return COND_SKIP (and start skipping in case 1187 * we weren't already), leaving the stack unmolested so later elif's 1188 * don't screw up... 1189 */ 1190 skipLine = TRUE; 1191 return (COND_SKIP); 1192 } 1193 1194 if (condTop < 0) { 1195 /* 1196 * This is the one case where we can definitely proclaim a fatal 1197 * error. If we don't, we're hosed. 1198 */ 1199 Parse_Error(PARSE_FATAL, "Too many nested if's. %d max.", MAXIF); 1200 return (COND_INVALID); 1201 } else { 1202 condStack[condTop] = value; 1203 condLineno[condTop] = lineno; 1204 skipLine = !value; 1205 return (value ? COND_PARSE : COND_SKIP); 1206 } 1207} 1208 1209/*- 1210 *----------------------------------------------------------------------- 1211 * Cond_End -- 1212 * Make sure everything's clean at the end of a makefile. 1213 * 1214 * Results: 1215 * None. 1216 * 1217 * Side Effects: 1218 * Parse_Error will be called if open conditionals are around. 1219 * 1220 *----------------------------------------------------------------------- 1221 */ 1222void 1223Cond_End(void) 1224{ 1225 int level; 1226 1227 if (condTop != MAXIF) { 1228 Parse_Error(PARSE_FATAL, "%d open conditional%s:", 1229 MAXIF - condTop + skipIfLevel, 1230 MAXIF - condTop + skipIfLevel== 1 ? "" : "s"); 1231 1232 for (level = skipIfLevel; level > 0; level--) 1233 Parse_Error(PARSE_FATAL, "\t%*sat line %d (skipped)", 1234 MAXIF - condTop + level + 1, "", skipIfLineno[level - 1]); 1235 for (level = condTop; level < MAXIF; level++) 1236 Parse_Error(PARSE_FATAL, "\t%*sat line %d " 1237 "(evaluated to %s)", MAXIF - level + skipIfLevel, "", 1238 condLineno[level], condStack[level] ? "true" : "false"); 1239 } 1240 condTop = MAXIF; 1241} 1242