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