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