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Add ifmedia(4) reference.
[dragonfly/netmp.git] / usr.bin / make / cond.c
blob6d6722b949b5dd06f1bea9c1c85e1b009b93032c
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 * $FreeBSD: src/usr.bin/make/cond.c,v 1.39 2005/02/07 07:49:16 harti Exp $
41 * $DragonFly: src/usr.bin/make/cond.c,v 1.51 2005/09/24 07:38:03 okumoto Exp $
42 */
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 bool CondProc(Parser *, 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 *, bool);
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(Parser *, bool);
124 static Token CondT(Parser *, bool);
125 static Token CondF(Parser *, bool);
126 static Token CondE(Parser *, bool);
127
128 static const struct If {
129 bool doNot; /* true if default function should be negated */
130 CondProc *defProc; /* Default function to apply */
131 bool 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 bool 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 bool 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 bool 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
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
188 CondGetArg(char **linePtr, char **argPtr, const char *func, bool parens)
189 {
190 char *cp;
191 size_t argLen;
192 Buffer *buf;
193
194 cp = *linePtr;
195 if (parens) {
196 while (*cp != OPEN_PAREN && *cp != '\0') {
197 cp++;
198 }
199 if (*cp == OPEN_PAREN) {
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 bool 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, *cp);
248 cp++;
249 }
250 }
251
252 while (*cp == ' ' || *cp == '\t') {
253 cp++;
254 }
255
256 Buf_AddByte(buf, '\0');
257 *argPtr = Buf_Data(buf);
258 argLen = Buf_Size(buf);
259 Buf_Destroy(buf, false);
260
261 if (parens) {
262 if (*cp == CLOSE_PAREN) {
263 /*
264 * Advance pointer past close parenthesis.
265 */
266 cp++;
267 *linePtr = cp;
268 return (argLen);
269 } else {
270 Parse_Error(PARSE_WARNING,
271 "Missing closing parenthesis for %s()", func);
272 return (0);
273 /* XXX memory leak of argPtr? */
274 }
275 } else {
276 *linePtr = cp;
277 return (argLen);
278 }
279 }
280
281 /**
282 * CondDoDefined
283 * Handle the 'defined' function for conditionals.
284 *
285 * Results:
286 * true if the given variable is defined.
287 */
288 static bool
289 CondDoDefined(Parser *parser __unused, int argLen, char *arg)
290 {
291 char savec = arg[argLen];
292 bool result;
293
294 arg[argLen] = '\0';
295 if (Var_Value(arg, VAR_CMD) != NULL) {
296 result = true;
297 } else {
298 result = false;
299 }
300 arg[argLen] = savec;
301 return (result);
302 }
303
304 /**
305 * CondDoMake
306 * Handle the 'make' function for conditionals.
307 *
308 * Results:
309 * true if the given target is being made.
310 */
311 static bool
312 CondDoMake(Parser *parser, int argLen, char *arg)
313 {
314 char savec = arg[argLen];
315 bool result;
316 const LstNode *ln;
317
318 arg[argLen] = '\0';
319 result = false;
320 LST_FOREACH(ln, parser->create) {
321 if (Str_Match(Lst_Datum(ln), arg)) {
322 result = true;
323 break;
324 }
325 }
326 arg[argLen] = savec;
327 return (result);
328 }
329
330 /**
331 * CondDoExists
332 * See if the given file exists.
333 *
334 * Results:
335 * true if the file exists and false if it does not.
336 */
337 static bool
338 CondDoExists(Parser *parser __unused, int argLen, char *arg)
339 {
340 char savec = arg[argLen];
341 bool result;
342 char *path;
343
344 arg[argLen] = '\0';
345 path = Path_FindFile(arg, &dirSearchPath);
346 if (path != NULL) {
347 result = true;
348 free(path);
349 } else {
350 result = false;
351 }
352 arg[argLen] = savec;
353 return (result);
354 }
355
356 /**
357 * CondDoTarget
358 * See if the given node exists and is an actual target.
359 *
360 * Results:
361 * true if the node exists as a target and false if it does not.
362 */
363 static bool
364 CondDoTarget(Parser *parser __unused, int argLen, char *arg)
365 {
366 char savec = arg[argLen];
367 bool result;
368 GNode *gn;
369
370 arg[argLen] = '\0';
371 gn = Targ_FindNode(arg, TARG_NOCREATE);
372 if ((gn != NULL) && !OP_NOP(gn->type)) {
373 result = true;
374 } else {
375 result = false;
376 }
377 arg[argLen] = savec;
378 return (result);
379 }
380
381 /**
382 * CondCvtArg
383 * Convert the given number into a double. If the number begins
384 * with 0x, it is interpreted as a hexadecimal integer
385 * and converted to a double from there. All other strings just have
386 * strtod called on them.
387 *
388 * Results:
389 * Sets 'value' to double value of string.
390 * Returns address of the first character after the last valid
391 * character of the converted number.
392 *
393 * Side Effects:
394 * Can change 'value' even if string is not a valid number.
395 */
396 static char *
397 CondCvtArg(char *str, double *value)
398 {
399
400 if ((*str == '0') && (str[1] == 'x')) {
401 long i;
402
403 for (str += 2, i = 0; ; str++) {
404 int x;
405
406 if (isdigit((unsigned char)*str))
407 x = *str - '0';
408 else if (isxdigit((unsigned char)*str))
409 x = 10 + *str -
410 isupper((unsigned char)*str) ? 'A' : 'a';
411 else {
412 *value = (double)i;
413 return (str);
414 }
415 i = (i << 4) + x;
416 }
417
418 } else {
419 char *eptr;
420
421 *value = strtod(str, &eptr);
422 return (eptr);
423 }
424 }
425
426 /**
427 * CondToken
428 * Return the next token from the input.
429 *
430 * Results:
431 * A Token for the next lexical token in the stream.
432 *
433 * Side Effects:
434 * condPushback will be set back to None if it is used.
435 */
436 static Token
437 CondToken(Parser *parser, bool doEval)
438 {
439 Token t;
440
441 if (condPushBack != None) {
442 t = condPushBack;
443 condPushBack = None;
444 return (t);
445 }
446
447 while (*condExpr == ' ' || *condExpr == '\t') {
448 condExpr++;
449 }
450
451 switch (*condExpr) {
452 case OPEN_PAREN:
453 t = LParen;
454 condExpr++;
455 break;
456 case CLOSE_PAREN:
457 t = RParen;
458 condExpr++;
459 break;
460 case '|':
461 if (condExpr[1] == '|') {
462 condExpr++;
463 }
464 condExpr++;
465 t = Or;
466 break;
467 case '&':
468 if (condExpr[1] == '&') {
469 condExpr++;
470 }
471 condExpr++;
472 t = And;
473 break;
474 case '!':
475 t = Not;
476 condExpr++;
477 break;
478 case '\n':
479 case '\0':
480 t = EndOfFile;
481 break;
482 case '$':{
483 char *lhs;
484 const char *op;
485 char *rhs;
486 char zero[] = "0";
487 size_t varSpecLen = 0;
488 bool doFree;
489
490 /*
491 * Parse the variable spec and skip over it, saving
492 * its value in lhs.
493 */
494 t = Err;
495 lhs = Var_Parse(condExpr, VAR_CMD, doEval,
496 &varSpecLen, &doFree);
497 if (lhs == var_Error) {
498 /*
499 * Even if !doEval, we still report syntax
500 * errors, which is what getting var_Error
501 * back with !doEval means.
502 */
503 return (Err);
504 }
505 condExpr += varSpecLen;
506
507 if (!isspace((unsigned char)*condExpr) &&
508 strchr("!=><", *condExpr) == NULL) {
509 Buffer *buf;
510
511 buf = Buf_Init(0);
512
513 Buf_Append(buf, lhs);
514
515 if (doFree)
516 free(lhs);
517
518 for (; *condExpr &&
519 !isspace((unsigned char)*condExpr);
520 condExpr++)
521 Buf_AddByte(buf, *condExpr);
522
523 Buf_AddByte(buf, '\0');
524 lhs = Buf_Data(buf);
525 Buf_Destroy(buf, false);
526
527 doFree = true;
528 }
529
530 /*
531 * Skip whitespace to get to the operator
532 */
533 while (isspace((unsigned char)*condExpr))
534 condExpr++;
535
536 /*
537 * Make sure the operator is a valid one. If it isn't
538 * a known relational operator, pretend we got a != 0
539 * comparison.
540 */
541 op = condExpr;
542 switch (*condExpr) {
543 case '!':
544 case '=':
545 case '<':
546 case '>':
547 if (condExpr[1] == '=') {
548 condExpr += 2;
549 } else {
550 condExpr += 1;
551 }
552 while (isspace((unsigned char)*condExpr)) {
553 condExpr++;
554 }
555 if (*condExpr == '\0') {
556 Parse_Error(PARSE_WARNING,
557 "Missing right-hand-side of operator");
558 goto error;
559 }
560 rhs = condExpr;
561 break;
562 default:
563 op = "!=";
564 rhs = zero;
565 break;
566 }
567
568 if (*rhs == '"') {
569 /*
570 * Doing a string comparison. Only allow ==
571 * and != for * operators.
572 */
573 char *string;
574 char *cp, *cp2;
575 int qt;
576 Buffer *buf;
577
578 do_string_compare:
579 if (((*op != '!') && (*op != '=')) ||
580 (op[1] != '=')) {
581 Parse_Error(PARSE_WARNING,
582 "String comparison operator should "
583 "be either == or !=");
584 goto error;
585 }
586 buf = Buf_Init(0);
587 qt = *rhs == '"' ? 1 : 0;
588
589 for (cp = &rhs[qt];
590 ((qt && (*cp != '"')) ||
591 (!qt && strchr(" \t)", *cp) == NULL)) &&
592 (*cp != '\0'); cp++) {
593 if ((*cp == '\\') && (cp[1] != '\0')) {
594 /*
595 * Backslash escapes things
596 * -- skip over next
597 * character, *
598 * if it exists.
599 */
600 cp++;
601 Buf_AddByte(buf, *cp);
602
603 } else if (*cp == '$') {
604 size_t len = 0;
605 bool freeIt;
606
607 cp2 = Var_Parse(cp, VAR_CMD,
608 doEval, &len, &freeIt);
609 if (cp2 != var_Error) {
610 Buf_Append(buf, cp2);
611 if (freeIt) {
612 free(cp2);
613 }
614 cp += len - 1;
615 } else {
616 Buf_AddByte(buf, *cp);
617 }
618 } else {
619 Buf_AddByte(buf, *cp);
620 }
621 }
622
623 string = Buf_Peel(buf);
624
625 DEBUGF(COND, ("lhs = \"%s\", rhs = \"%s\", "
626 "op = %.2s\n", lhs, string, op));
627 /*
628 * Null-terminate rhs and perform the
629 * comparison. t is set to the result.
630 */
631 if (*op == '=') {
632 t = strcmp(lhs, string) ? False : True;
633 } else {
634 t = strcmp(lhs, string) ? True : False;
635 }
636 free(string);
637 if (rhs == condExpr) {
638 if (*cp == '\0' || (!qt && *cp == CLOSE_PAREN))
639 condExpr = cp;
640 else
641 condExpr = cp + 1;
642 }
643 } else {
644 /*
645 * rhs is either a float or an integer.
646 * Convert both the lhs and the rhs to a
647 * double and compare the two.
648 */
649 double left, right;
650 char *string;
651
652 if (*CondCvtArg(lhs, &left) != '\0')
653 goto do_string_compare;
654 if (*rhs == '$') {
655 size_t len = 0;
656 bool freeIt;
657
658 string = Var_Parse(rhs, VAR_CMD, doEval,
659 &len, &freeIt);
660 if (string == var_Error) {
661 right = 0.0;
662 } else {
663 if (*CondCvtArg(string,
664 &right) != '\0') {
665 if (freeIt)
666 free(string);
667 goto do_string_compare;
668 }
669 if (freeIt)
670 free(string);
671 if (rhs == condExpr)
672 condExpr += len;
673 }
674 } else {
675 char *c = CondCvtArg(rhs, &right);
676
677 if (c == rhs)
678 goto do_string_compare;
679 if (rhs == condExpr) {
680 /*
681 * Skip over the right-hand
682 * side
683 */
684 condExpr = c;
685 }
686 }
687
688 DEBUGF(COND, ("left = %f, right = %f, "
689 "op = %.2s\n", left, right, op));
690 switch (op[0]) {
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 Parse_Error(PARSE_WARNING,
702 "Unknown operator");
703 goto error;
704 }
705 t = (left == right ? True : False);
706 break;
707 case '<':
708 if (op[1] == '=') {
709 t = (left <= right ? True : False);
710 } else {
711 t = (left < right ? True : False);
712 }
713 break;
714 case '>':
715 if (op[1] == '=') {
716 t = (left >= right ? True : False);
717 } else {
718 t = (left > right ? True : False);
719 }
720 break;
721 default:
722 break;
723 }
724 }
725 error:
726 if (doFree)
727 free(lhs);
728 break;
729 }
730
731 default:{
732 CondProc *evalProc;
733 bool invert = false;
734 char *arg;
735 int arglen;
736
737 if (strncmp(condExpr, "defined", 7) == 0) {
738 /*
739 * Use CondDoDefined to evaluate the argument
740 * and CondGetArg to extract the argument
741 * from the 'function call'.
742 */
743 evalProc = CondDoDefined;
744 condExpr += 7;
745 arglen = CondGetArg(&condExpr, &arg,
746 "defined", true);
747 if (arglen == 0) {
748 condExpr -= 7;
749 goto use_default;
750 }
751 } else if (strncmp(condExpr, "make", 4) == 0) {
752 /*
753 * Use CondDoMake to evaluate the argument
754 * and CondGetArg to extract the argument
755 * from the 'function call'.
756 */
757 evalProc = CondDoMake;
758 condExpr += 4;
759 arglen = CondGetArg(&condExpr, &arg,
760 "make", true);
761 if (arglen == 0) {
762 condExpr -= 4;
763 goto use_default;
764 }
765 } else if (strncmp(condExpr, "exists", 6) == 0) {
766 /*
767 * Use CondDoExists to evaluate the argument
768 * and CondGetArg to extract the argument
769 * from the 'function call'.
770 */
771 evalProc = CondDoExists;
772 condExpr += 6;
773 arglen = CondGetArg(&condExpr, &arg,
774 "exists", true);
775 if (arglen == 0) {
776 condExpr -= 6;
777 goto use_default;
778 }
779 } else if (strncmp(condExpr, "empty", 5) == 0) {
780 /*
781 * Use Var_Parse to parse the spec in parens
782 * and return True if the resulting string is
783 * empty.
784 */
785 size_t length;
786 bool doFree;
787 char *val;
788
789 condExpr += 5;
790
791 for (arglen = 0;
792 condExpr[arglen] != OPEN_PAREN &&
793 condExpr[arglen] != '\0'; arglen += 1)
794 continue;
795
796 if (condExpr[arglen] != '\0') {
797 length = 0;
798 val = Var_Parse(&condExpr[arglen - 1],
799 VAR_CMD, false, &length, &doFree);
800 if (val == var_Error) {
801 t = Err;
802 } else {
803 /*
804 * A variable is empty when
805 * it just contains spaces...
806 * 4/15/92, christos
807 */
808 char *p;
809
810 for (p = val;
811 *p &&
812 isspace((unsigned char)*p);
813 p++)
814 continue;
815 t = (*p == '\0') ? True : False;
816 }
817 if (doFree) {
818 free(val);
819 }
820 /*
821 * Advance condExpr to beyond the
822 * closing ). Note that we subtract
823 * one from arglen + length b/c
824 * length is calculated from
825 * condExpr[arglen - 1].
826 */
827 condExpr += arglen + length - 1;
828 } else {
829 condExpr -= 5;
830 goto use_default;
831 }
832 break;
833
834 } else if (strncmp(condExpr, "target", 6) == 0) {
835 /*
836 * Use CondDoTarget to evaluate the argument
837 * and CondGetArg to extract the argument
838 * from the 'function call'.
839 */
840 evalProc = CondDoTarget;
841 condExpr += 6;
842 arglen = CondGetArg(&condExpr, &arg,
843 "target", true);
844 if (arglen == 0) {
845 condExpr -= 6;
846 goto use_default;
847 }
848 } else {
849 /*
850 * The symbol is itself the argument to the
851 * default function. We advance condExpr to
852 * the end of the symbol by hand (the next
853 * whitespace, closing paren or binary
854 * operator) and set to invert the evaluation
855 * function if condInvert is true.
856 */
857 use_default:
858 invert = condInvert;
859 evalProc = condDefProc;
860 arglen = CondGetArg(&condExpr, &arg, "", false);
861 }
862
863 /*
864 * Evaluate the argument using the set function. If
865 * invert is true, we invert the sense of the
866 * function.
867 */
868 t = (!doEval || evalProc(parser, arglen, arg) ?
869 (invert ? False : True) :
870 (invert ? True : False));
871 free(arg);
872 break;
873 }
874 }
875 return (t);
876 }
877
878 /**
879 * CondT
880 * Parse a single term in the expression. This consists of a terminal
881 * symbol or Not and a terminal symbol (not including the binary
882 * operators):
883 * T -> defined(variable) | make(target) | exists(file) | symbol
884 * T -> ! T | ( E )
885 *
886 * Results:
887 * True, False or Err.
888 *
889 * Side Effects:
890 * Tokens are consumed.
891 */
892 static Token
893 CondT(Parser *parser, bool doEval)
894 {
895 Token t;
896
897 t = CondToken(parser, doEval);
898 if (t == EndOfFile) {
899 /*
900 * If we reached the end of the expression, the expression
901 * is malformed...
902 */
903 t = Err;
904 } else if (t == LParen) {
905 /*
906 * T -> ( E )
907 */
908 t = CondE(parser, doEval);
909 if (t != Err) {
910 if (CondToken(parser, doEval) != RParen) {
911 t = Err;
912 }
913 }
914 } else if (t == Not) {
915 t = CondT(parser, doEval);
916 if (t == True) {
917 t = False;
918 } else if (t == False) {
919 t = True;
920 }
921 }
922 return (t);
923 }
924
925 /**
926 * CondF --
927 * Parse a conjunctive factor (nice name, wot?)
928 * F -> T && F | T
929 *
930 * Results:
931 * True, False or Err
932 *
933 * Side Effects:
934 * Tokens are consumed.
935 */
936 static Token
937 CondF(Parser *parser, bool doEval)
938 {
939 Token l, o;
940
941 l = CondT(parser, doEval);
942 if (l != Err) {
943 o = CondToken(parser, doEval);
944
945 if (o == And) {
946 /*
947 * F -> T && F
948 *
949 * If T is False, the whole thing will be False, but
950 * we have to parse the r.h.s. anyway (to throw it
951 * away). If T is True, the result is the r.h.s.,
952 * be it an Err or no.
953 */
954 if (l == True) {
955 l = CondF(parser, doEval);
956 } else {
957 CondF(parser, false);
958 }
959 } else {
960 /*
961 * F -> T
962 */
963 CondPushBack(o);
964 }
965 }
966 return (l);
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 static Token
981 CondE(Parser *parser, bool doEval)
982 {
983 Token l, o;
984
985 l = CondF(parser, doEval);
986 if (l != Err) {
987 o = CondToken(parser, doEval);
988
989 if (o == Or) {
990 /*
991 * E -> F || E
992 *
993 * A similar thing occurs for ||, except that here we
994 * make sure the l.h.s. is False before we bother to
995 * evaluate the r.h.s. Once again, if l is False, the
996 * result is the r.h.s. and once again if l is True,
997 * we parse the r.h.s. to throw it away.
998 */
999 if (l == False) {
1000 l = CondE(parser, doEval);
1001 } else {
1002 CondE(parser, false);
1003 }
1004 } else {
1005 /*
1006 * E -> F
1007 */
1008 CondPushBack(o);
1009 }
1010 }
1011 return (l);
1012 }
1013
1014 /**
1015 * Cond_If
1016 * Handle .if<X> and .elif<X> directives.
1017 * This function is called even when we're skipping.
1018 */
1019 void
1020 Cond_If(Parser *parser, char *line, int code, int lineno)
1021 {
1022 const struct If *ifp;
1023 bool value;
1024
1025 ifp = &ifs[code];
1026
1027 if (ifp->isElse) {
1028 if (condTop == MAXIF) {
1029 Parse_Error(PARSE_FATAL, "if-less elif");
1030 return;
1031 }
1032 if (skipIfLevel != 0) {
1033 /*
1034 * If skipping this conditional, just ignore
1035 * the whole thing. If we don't, the user
1036 * might be employing a variable that's
1037 * undefined, for which there's an enclosing
1038 * ifdef that we're skipping...
1039 */
1040 skipIfLineno[skipIfLevel - 1] = lineno;
1041 return;
1042 }
1043
1044 } else if (skipLine) {
1045 /*
1046 * Don't even try to evaluate a conditional that's
1047 * not an else if we're skipping things...
1048 */
1049 skipIfLineno[skipIfLevel] = lineno;
1050 skipIfLevel += 1;
1051 return;
1052 }
1053
1054 /*
1055 * Initialize file-global variables for parsing
1056 */
1057 condDefProc = ifp->defProc;
1058 condInvert = ifp->doNot;
1059
1060 while (*line == ' ' || *line == '\t') {
1061 line++;
1062 }
1063
1064 condExpr = line;
1065 condPushBack = None;
1066
1067 switch (CondE(parser, true)) {
1068 case True:
1069 if (CondToken(parser, true) != EndOfFile)
1070 goto err;
1071 value = true;
1072 break;
1073
1074 case False:
1075 if (CondToken(parser, true) != EndOfFile)
1076 goto err;
1077 value = false;
1078 break;
1079
1080 case Err:
1081 err: Parse_Error(PARSE_FATAL, "Malformed conditional (%s)", line);
1082 return;
1083
1084 default:
1085 abort();
1086 }
1087
1088 if (!ifp->isElse) {
1089 /* push this value */
1090 condTop -= 1;
1091
1092 } else if (skipIfLevel != 0 || condStack[condTop]) {
1093 /*
1094 * If this is an else-type conditional, it should only take
1095 * effect if its corresponding if was evaluated and false.
1096 * If its if was true or skipped, we return COND_SKIP (and
1097 * start skipping in case we weren't already), leaving the
1098 * stack unmolested so later elif's don't screw up...
1099 */
1100 skipLine = true;
1101 return;
1102 }
1103
1104 if (condTop < 0) {
1105 /*
1106 * This is the one case where we can definitely proclaim a fatal
1107 * error. If we don't, we're hosed.
1108 */
1109 Parse_Error(PARSE_FATAL, "Too many nested if's. %d max.",MAXIF);
1110 return;
1111 }
1112
1113 /* push */
1114 condStack[condTop] = value;
1115 condLineno[condTop] = lineno;
1116 skipLine = !value;
1117 }
1118
1119 /**
1120 * Cond_Else
1121 * Handle .else statement.
1122 */
1123 void
1124 Cond_Else(Parser *parser __unused, char *line __unused, int code __unused, int lineno __unused)
1125 {
1126
1127 while (isspace((u_char)*line))
1128 line++;
1129
1130 if (*line != '\0' && (warn_flags & WARN_DIRSYNTAX)) {
1131 Parse_Error(PARSE_WARNING, "junk after .else ignored '%s'",
1132 line);
1133 }
1134
1135 if (condTop == MAXIF) {
1136 Parse_Error(PARSE_FATAL, "if-less else");
1137 return;
1138 }
1139 if (skipIfLevel != 0)
1140 return;
1141
1142 if (skipIfLevel != 0 || condStack[condTop]) {
1143 /*
1144 * An else should only take effect if its corresponding if was
1145 * evaluated and false.
1146 * If its if was true or skipped, we return COND_SKIP (and
1147 * start skipping in case we weren't already), leaving the
1148 * stack unmolested so later elif's don't screw up...
1149 * XXX How does this work with two .else's?
1150 */
1151 skipLine = true;
1152 return;
1153 }
1154
1155 /* inverse value */
1156 condStack[condTop] = !condStack[condTop];
1157 skipLine = !condStack[condTop];
1158 }
1159
1160 /**
1161 * Cond_Endif
1162 * Handle .endif statement.
1163 */
1164 void
1165 Cond_Endif(Parser *parser __unused, char *line __unused, int code __unused, int lineno __unused)
1166 {
1167
1168 while (isspace((u_char)*line))
1169 line++;
1170
1171 if (*line != '\0' && (warn_flags & WARN_DIRSYNTAX)) {
1172 Parse_Error(PARSE_WARNING, "junk after .endif ignored '%s'",
1173 line);
1174 }
1175
1176 /*
1177 * End of a conditional section. If skipIfLevel is non-zero,
1178 * that conditional was skipped, so lines following it should
1179 * also be skipped. Hence, we return COND_SKIP. Otherwise,
1180 * the conditional was read so succeeding lines should be
1181 * parsed (think about it...) so we return COND_PARSE, unless
1182 * this endif isn't paired with a decent if.
1183 */
1184 if (skipIfLevel != 0) {
1185 skipIfLevel -= 1;
1186 return;
1187 }
1188
1189 if (condTop == MAXIF) {
1190 Parse_Error(PARSE_FATAL, "if-less endif");
1191 return;
1192 }
1193
1194 /* pop */
1195 skipLine = false;
1196 condTop += 1;
1197 }
1198
1199 /**
1200 * Cond_End
1201 * Make sure everything's clean at the end of a makefile.
1202 *
1203 * Side Effects:
1204 * Parse_Error will be called if open conditionals are around.
1205 */
1206 void
1207 Cond_End(Parser *parser __unused, char *line __unused, int code __unused, int lineno __unused)
1208 {
1209 int level;
1210
1211 if (condTop != MAXIF) {
1212 Parse_Error(PARSE_FATAL, "%d open conditional%s:",
1213 MAXIF - condTop + skipIfLevel,
1214 MAXIF - condTop + skipIfLevel== 1 ? "" : "s");
1215
1216 for (level = skipIfLevel; level > 0; level--)
1217 Parse_Error(PARSE_FATAL, "\t%*sat line %d (skipped)",
1218 MAXIF - condTop + level + 1, "",
1219 skipIfLineno[level - 1]);
1220 for (level = condTop; level < MAXIF; level++)
1221 Parse_Error(PARSE_FATAL, "\t%*sat line %d "
1222 "(evaluated to %s)", MAXIF - level + skipIfLevel,
1223 "", condLineno[level],
1224 condStack[level] ? "true" : "false");
1225 }
1226 condTop = MAXIF;
1227 }
MP support for (parts of) the network stack