usr.bin/diff3/diff3.c

   1 /*      $OpenBSD: diff3prog.c,v 1.11 2009/10/27 23:59:37 deraadt Exp $  */
   2
   3 /*
   4  * Copyright (C) Caldera International Inc.  2001-2002.
   5  * All rights reserved.
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  * 1. Redistributions of source code and documentation must retain the above
  11  *    copyright notice, this list of conditions and the following disclaimer.
  12  * 2. Redistributions in binary form must reproduce the above copyright
  13  *    notice, this list of conditions and the following disclaimer in the
  14  *    documentation and/or other materials provided with the distribution.
  15  * 3. All advertising materials mentioning features or use of this software
  16  *    must display the following acknowledgement:
  17  *      This product includes software developed or owned by Caldera
  18  *      International, Inc.
  19  * 4. Neither the name of Caldera International, Inc. nor the names of other
  20  *    contributors may be used to endorse or promote products derived from
  21  *    this software without specific prior written permission.
  22  *
  23  * USE OF THE SOFTWARE PROVIDED FOR UNDER THIS LICENSE BY CALDERA
  24  * INTERNATIONAL, INC. AND CONTRIBUTORS ``AS IS'' AND ANY EXPRESS OR
  25  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  26  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  27  * IN NO EVENT SHALL CALDERA INTERNATIONAL, INC. BE LIABLE FOR ANY DIRECT,
  28  * INDIRECT INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
  29  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
  30  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  31  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
  32  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
  33  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  34  * POSSIBILITY OF SUCH DAMAGE.
  35  */
  36 /*-
  37  * Copyright (c) 1991, 1993
  38  *      The Regents of the University of California.  All rights reserved.
  39  *
  40  * Redistribution and use in source and binary forms, with or without
  41  * modification, are permitted provided that the following conditions
  42  * are met:
  43  * 1. Redistributions of source code must retain the above copyright
  44  *    notice, this list of conditions and the following disclaimer.
  45  * 2. Redistributions in binary form must reproduce the above copyright
  46  *    notice, this list of conditions and the following disclaimer in the
  47  *    documentation and/or other materials provided with the distribution.
  48  * 3. Neither the name of the University nor the names of its contributors
  49  *    may be used to endorse or promote products derived from this software
  50  *    without specific prior written permission.
  51  *
  52  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  53  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  54  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  55  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  56  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  57  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  58  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  59  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  60  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  61  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  62  * SUCH DAMAGE.
  63  *
  64  *      @(#)diff3.c     8.1 (Berkeley) 6/6/93
  65  */
  66
  67 #if 0
  68 #ifndef lint
  69 static char sccsid[] = "@(#)diff3.c     8.1 (Berkeley) 6/6/93";
  70 #endif
  71 #endif /* not lint */
  72 #include <sys/cdefs.h>
  73 __FBSDID("$FreeBSD$");
  74
  75 #include <sys/capsicum.h>
  76 #include <sys/procdesc.h>
  77 #include <sys/types.h>
  78 #include <sys/event.h>
  79 #include <sys/wait.h>
  80
  81 #include <capsicum_helpers.h>
  82 #include <ctype.h>
  83 #include <err.h>
  84 #include <getopt.h>
  85 #include <stdio.h>
  86 #include <stdlib.h>
  87 #include <limits.h>
  88 #include <inttypes.h>
  89 #include <string.h>
  90 #include <unistd.h>
  91
  92
  93 /*
  94  * "from" is first in range of changed lines; "to" is last+1
  95  * from=to=line after point of insertion for added lines.
  96  */
  97 struct range {
  98         int from;
  99         int to;
 100 };
 101
 102 struct diff {
 103 #define DIFF_TYPE2 2
 104 #define DIFF_TYPE3 3
 105         int type;
 106 #if DEBUG
 107         char *line;
 108 #endif  /* DEBUG */
 109
 110         /* Ranges as lines */
 111         struct range old;
 112         struct range new;
 113 };
 114
 115 #define EFLAG_NONE      0
 116 #define EFLAG_OVERLAP   1
 117 #define EFLAG_NOOVERLAP 2
 118 #define EFLAG_UNMERGED  3
 119
 120 static size_t szchanges;
 121
 122 static struct diff *d13;
 123 static struct diff *d23;
 124 /*
 125  * "de" is used to gather editing scripts.  These are later spewed out in
 126  * reverse order.  Its first element must be all zero, the "old" and "new"
 127  * components of "de" contain line positions. Array overlap indicates which
 128  * sections in "de" correspond to lines that are different in all three files.
 129  */
 130 static struct diff *de;
 131 static char *overlap;
 132 static int  overlapcnt;
 133 static FILE *fp[3];
 134 static int cline[3];            /* # of the last-read line in each file (0-2) */
 135 /*
 136  * The latest known correspondence between line numbers of the 3 files
 137  * is stored in last[1-3];
 138  */
 139 static int last[4];
 140 static int Aflag, eflag, iflag, mflag, Tflag;
 141 static int oflag;               /* indicates whether to mark overlaps (-E or -X) */
 142 static int strip_cr;
 143 static char *f1mark, *f2mark, *f3mark;
 144 static const char *oldmark = "<<<<<<<";
 145 static const char *orgmark = "|||||||";
 146 static const char *newmark = ">>>>>>>";
 147
 148 static bool duplicate(struct range *, struct range *);
 149 static int edit(struct diff *, bool, int, int);
 150 static char *getchange(FILE *);
 151 static char *get_line(FILE *, size_t *);
 152 static int readin(int fd, struct diff **);
 153 static int skip(int, int, const char *);
 154 static void change(int, struct range *, bool);
 155 static void keep(int, struct range *);
 156 static void merge(int, int);
 157 static void prange(struct range *, bool);
 158 static void repos(int);
 159 static void edscript(int) __dead2;
 160 static void Ascript(int) __dead2;
 161 static void mergescript(int) __dead2;
 162 static void increase(void);
 163 static void usage(void);
 164 static void printrange(FILE *, struct range *);
 165
 166 static const char diff3_version[] = "FreeBSD diff3 20220517";
 167
 168 enum {
 169         DIFFPROG_OPT,
 170         STRIPCR_OPT,
 171         HELP_OPT,
 172         VERSION_OPT
 173 };
 174
 175 #define DIFF_PATH "/usr/bin/diff"
 176
 177 #define OPTIONS "3aAeEiL:mTxX"
 178 static struct option longopts[] = {
 179         { "ed",                 no_argument,            NULL,   'e' },
 180         { "show-overlap",       no_argument,            NULL,   'E' },
 181         { "overlap-only",       no_argument,            NULL,   'x' },
 182         { "initial-tab",        no_argument,            NULL,   'T' },
 183         { "text",               no_argument,            NULL,   'a' },
 184         { "strip-trailing-cr",  no_argument,            NULL,   STRIPCR_OPT },
 185         { "show-all",           no_argument,            NULL,   'A' },
 186         { "easy-only",          no_argument,            NULL,   '3' },
 187         { "merge",              no_argument,            NULL,   'm' },
 188         { "label",              required_argument,      NULL,   'L' },
 189         { "diff-program",       required_argument,      NULL,   DIFFPROG_OPT },
 190         { "help",               no_argument,            NULL,   HELP_OPT},
 191         { "version",            no_argument,            NULL,   VERSION_OPT}
 192 };
 193
 194 static void
 195 usage(void)
 196 {
 197         fprintf(stderr, "usage: diff3 [-3aAeEimTxX] [-L label1] [-L label2] "
 198             "[-L label3] file1 file2 file3\n");
 199 }
 200
 201 static int
 202 readin(int fd, struct diff **dd)
 203 {
 204         int a, b, c, d;
 205         size_t i;
 206         char kind, *p;
 207         FILE *f;
 208
 209         f = fdopen(fd, "r");
 210         if (f == NULL)
 211                 err(2, "fdopen");
 212         for (i = 0; (p = getchange(f)); i++) {
 213 #if DEBUG
 214                 (*dd)[i].line = strdup(p);
 215 #endif  /* DEBUG */
 216
 217                 if (i >= szchanges - 1)
 218                         increase();
 219                 a = b = (int)strtoimax(p, &p, 10);
 220                 if (*p == ',') {
 221                         p++;
 222                         b = (int)strtoimax(p, &p, 10);
 223                 }
 224                 kind = *p++;
 225                 c = d = (int)strtoimax(p, &p, 10);
 226                 if (*p == ',') {
 227                         p++;
 228                         d = (int)strtoimax(p, &p, 10);
 229                 }
 230                 if (kind == 'a')
 231                         a++;
 232                 if (kind == 'd')
 233                         c++;
 234                 b++;
 235                 d++;
 236                 (*dd)[i].old.from = a;
 237                 (*dd)[i].old.to = b;
 238                 (*dd)[i].new.from = c;
 239                 (*dd)[i].new.to = d;
 240         }
 241         if (i) {
 242                 (*dd)[i].old.from = (*dd)[i - 1].old.to;
 243                 (*dd)[i].new.from = (*dd)[i - 1].new.to;
 244         }
 245         fclose(f);
 246         return (i);
 247 }
 248
 249 static int
 250 diffexec(const char *diffprog, char **diffargv, int fd[])
 251 {
 252         int pd;
 253
 254         switch (pdfork(&pd, PD_CLOEXEC)) {
 255         case 0:
 256                 close(fd[0]);
 257                 if (dup2(fd[1], STDOUT_FILENO) == -1)
 258                         err(2, "child could not duplicate descriptor");
 259                 close(fd[1]);
 260                 execvp(diffprog, diffargv);
 261                 err(2, "could not execute diff: %s", diffprog);
 262                 break;
 263         case -1:
 264                 err(2, "could not fork");
 265                 break;
 266         }
 267         close(fd[1]);
 268         return (pd);
 269 }
 270
 271 static char *
 272 getchange(FILE *b)
 273 {
 274         char *line;
 275
 276         while ((line = get_line(b, NULL))) {
 277                 if (isdigit((unsigned char)line[0]))
 278                         return (line);
 279         }
 280         return (NULL);
 281 }
 282
 283
 284 static char *
 285 get_line(FILE *b, size_t *n)
 286 {
 287         ssize_t len;
 288         static char *buf = NULL;
 289         static size_t bufsize = 0;
 290
 291         if ((len = getline(&buf, &bufsize, b)) < 0)
 292                 return (NULL);
 293
 294         if (strip_cr && len >= 2 && strcmp("\r\n", &(buf[len - 2])) == 0) {
 295                 buf[len - 2] = '\n';
 296                 buf[len - 1] = '\0';
 297                 len--;
 298         }
 299
 300         if (n != NULL)
 301                 *n = len;
 302
 303         return (buf);
 304 }
 305
 306 static void
 307 merge(int m1, int m2)
 308 {
 309         struct diff *d1, *d2, *d3;
 310         int j, t1, t2;
 311         bool dup = false;
 312
 313         d1 = d13;
 314         d2 = d23;
 315         j = 0;
 316
 317         while (t1 = d1 < d13 + m1, t2 = d2 < d23 + m2, t1 || t2) {
 318                 /* first file is different from the others */
 319                 if (!t2 || (t1 && d1->new.to < d2->new.from)) {
 320                         /* stuff peculiar to 1st file */
 321                         if (eflag == EFLAG_NONE) {
 322                                 printf("====1\n");
 323                                 change(1, &d1->old, false);
 324                                 keep(2, &d1->new);
 325                                 change(3, &d1->new, false);
 326                         }
 327                         d1++;
 328                         continue;
 329                 }
 330                 /* second file is different from others */
 331                 if (!t1 || (t2 && d2->new.to < d1->new.from)) {
 332                         if (eflag == EFLAG_NONE) {
 333                                 printf("====2\n");
 334                                 keep(1, &d2->new);
 335                                 change(3, &d2->new, false);
 336                                 change(2, &d2->old, false);
 337                         } else if (Aflag || mflag) {
 338                                 // XXX-THJ: What does it mean for the second file to differ?
 339                                 j = edit(d2, dup, j, DIFF_TYPE2);
 340                         }
 341                         d2++;
 342                         continue;
 343                 }
 344                 /*
 345                  * Merge overlapping changes in first file
 346                  * this happens after extension (see below).
 347                  */
 348                 if (d1 + 1 < d13 + m1 && d1->new.to >= d1[1].new.from) {
 349                         d1[1].old.from = d1->old.from;
 350                         d1[1].new.from = d1->new.from;
 351                         d1++;
 352                         continue;
 353                 }
 354
 355                 /* merge overlapping changes in second */
 356                 if (d2 + 1 < d23 + m2 && d2->new.to >= d2[1].new.from) {
 357                         d2[1].old.from = d2->old.from;
 358                         d2[1].new.from = d2->new.from;
 359                         d2++;
 360                         continue;
 361                 }
 362                 /* stuff peculiar to third file or different in all */
 363                 if (d1->new.from == d2->new.from && d1->new.to == d2->new.to) {
 364                         dup = duplicate(&d1->old, &d2->old);
 365                         /*
 366                          * dup = 0 means all files differ
 367                          * dup = 1 means files 1 and 2 identical
 368                          */
 369                         if (eflag == EFLAG_NONE) {
 370                                 printf("====%s\n", dup ? "3" : "");
 371                                 change(1, &d1->old, dup);
 372                                 change(2, &d2->old, false);
 373                                 d3 = d1->old.to > d1->old.from ? d1 : d2;
 374                                 change(3, &d3->new, false);
 375                         } else {
 376                                 j = edit(d1, dup, j, DIFF_TYPE3);
 377                         }
 378                         dup = false;
 379                         d1++;
 380                         d2++;
 381                         continue;
 382                 }
 383                 /*
 384                  * Overlapping changes from file 1 and 2; extend changes
 385                  * appropriately to make them coincide.
 386                  */
 387                 if (d1->new.from < d2->new.from) {
 388                         d2->old.from -= d2->new.from - d1->new.from;
 389                         d2->new.from = d1->new.from;
 390                 } else if (d2->new.from < d1->new.from) {
 391                         d1->old.from -= d1->new.from - d2->new.from;
 392                         d1->new.from = d2->new.from;
 393                 }
 394                 if (d1->new.to > d2->new.to) {
 395                         d2->old.to += d1->new.to - d2->new.to;
 396                         d2->new.to = d1->new.to;
 397                 } else if (d2->new.to > d1->new.to) {
 398                         d1->old.to += d2->new.to - d1->new.to;
 399                         d1->new.to = d2->new.to;
 400                 }
 401         }
 402
 403         if (mflag)
 404                 mergescript(j);
 405         else if (Aflag)
 406                 Ascript(j);
 407         else if (eflag)
 408                 edscript(j);
 409 }
 410
 411 /*
 412  * The range of lines rold.from thru rold.to in file i is to be changed.
 413  * It is to be printed only if it does not duplicate something to be
 414  * printed later.
 415  */
 416 static void
 417 change(int i, struct range *rold, bool dup)
 418 {
 419
 420         printf("%d:", i);
 421         last[i] = rold->to;
 422         prange(rold, false);
 423         if (dup)
 424                 return;
 425         i--;
 426         skip(i, rold->from, NULL);
 427         skip(i, rold->to, "  ");
 428 }
 429
 430 /*
 431  * Print the range of line numbers, rold.from thru rold.to, as n1,n2 or
 432  * n1.
 433  */
 434 static void
 435 prange(struct range *rold, bool delete)
 436 {
 437
 438         if (rold->to <= rold->from)
 439                 printf("%da\n", rold->from - 1);
 440         else {
 441                 printf("%d", rold->from);
 442                 if (rold->to > rold->from + 1)
 443                         printf(",%d", rold->to - 1);
 444                 if (delete)
 445                         printf("d\n");
 446                 else
 447                         printf("c\n");
 448         }
 449 }
 450
 451 /*
 452  * No difference was reported by diff between file 1 (or 2) and file 3,
 453  * and an artificial dummy difference (trange) must be ginned up to
 454  * correspond to the change reported in the other file.
 455  */
 456 static void
 457 keep(int i, struct range *rnew)
 458 {
 459         int delta;
 460         struct range trange;
 461
 462         delta = last[3] - last[i];
 463         trange.from = rnew->from - delta;
 464         trange.to = rnew->to - delta;
 465         change(i, &trange, true);
 466 }
 467
 468 /*
 469  * skip to just before line number from in file "i".  If "pr" is non-NULL,
 470  * print all skipped stuff with string pr as a prefix.
 471  */
 472 static int
 473 skip(int i, int from, const char *pr)
 474 {
 475         size_t j, n;
 476         char *line;
 477
 478         for (n = 0; cline[i] < from - 1; n += j) {
 479                 if ((line = get_line(fp[i], &j)) == NULL)
 480                         errx(EXIT_FAILURE, "logic error");
 481                 if (pr != NULL)
 482                         printf("%s%s", Tflag == 1 ? "\t" : pr, line);
 483                 cline[i]++;
 484         }
 485         return ((int) n);
 486 }
 487
 488 /*
 489  * Return 1 or 0 according as the old range (in file 1) contains exactly
 490  * the same data as the new range (in file 2).
 491  */
 492 static bool
 493 duplicate(struct range *r1, struct range *r2)
 494 {
 495         int c, d;
 496         int nchar;
 497         int nline;
 498
 499         if (r1->to-r1->from != r2->to-r2->from)
 500                 return (0);
 501         skip(0, r1->from, NULL);
 502         skip(1, r2->from, NULL);
 503         nchar = 0;
 504         for (nline = 0; nline < r1->to - r1->from; nline++) {
 505                 do {
 506                         c = getc(fp[0]);
 507                         d = getc(fp[1]);
 508                         if (c == -1 && d == -1)
 509                                 break;
 510                         if (c == -1 || d == -1)
 511                                 errx(EXIT_FAILURE, "logic error");
 512                         nchar++;
 513                         if (c != d) {
 514                                 repos(nchar);
 515                                 return (0);
 516                         }
 517                 } while (c != '\n');
 518         }
 519         repos(nchar);
 520         return (1);
 521 }
 522
 523 static void
 524 repos(int nchar)
 525 {
 526         int i;
 527
 528         for (i = 0; i < 2; i++)
 529                 (void)fseek(fp[i], (long)-nchar, SEEK_CUR);
 530 }
 531
 532 /*
 533  * collect an editing script for later regurgitation
 534  */
 535 static int
 536 edit(struct diff *diff, bool dup, int j, int difftype)
 537 {
 538         if (!(eflag == EFLAG_UNMERGED ||
 539                 (!dup && eflag == EFLAG_OVERLAP ) ||
 540                 (dup && eflag == EFLAG_NOOVERLAP))) {
 541                 return (j);
 542         }
 543         j++;
 544         overlap[j] = !dup;
 545         if (!dup)
 546                 overlapcnt++;
 547
 548         de[j].type = difftype;
 549 #if DEBUG
 550         de[j].line = strdup(diff->line);
 551 #endif  /* DEBUG */
 552
 553         de[j].old.from = diff->old.from;
 554         de[j].old.to = diff->old.to;
 555         de[j].new.from = diff->new.from;
 556         de[j].new.to = diff->new.to;
 557         return (j);
 558 }
 559
 560 static void
 561 printrange(FILE *p, struct range *r)
 562 {
 563         char *line = NULL;
 564         size_t len = 0;
 565         int i = 1;
 566         ssize_t rlen = 0;
 567
 568         /* We haven't been asked to print anything */
 569         if (r->from == r->to)
 570                 return;
 571
 572         if (r->from > r->to)
 573                         errx(EXIT_FAILURE, "invalid print range");
 574
 575         /*
 576          * XXX-THJ: We read through all of the file for each range printed.
 577          * This duplicates work and will probably impact performance on large
 578          * files with lots of ranges.
 579          */
 580         fseek(p, 0L, SEEK_SET);
 581         while ((rlen = getline(&line, &len, p)) > 0) {
 582                 if (i >= r->from)
 583                         printf("%s", line);
 584                 if (++i > r->to - 1)
 585                         break;
 586         }
 587         free(line);
 588 }
 589
 590 /* regurgitate */
 591 static void
 592 edscript(int n)
 593 {
 594         bool delete;
 595
 596         for (; n > 0; n--) {
 597                 delete = (de[n].new.from == de[n].new.to);
 598                 if (!oflag || !overlap[n]) {
 599                         prange(&de[n].old, delete);
 600                 } else {
 601                         printf("%da\n", de[n].old.to - 1);
 602                         printf("=======\n");
 603                 }
 604                 printrange(fp[2], &de[n].new);
 605                 if (!oflag || !overlap[n]) {
 606                         if (!delete)
 607                                 printf(".\n");
 608                 } else {
 609                         printf("%s %s\n.\n", newmark, f3mark);
 610                         printf("%da\n%s %s\n.\n", de[n].old.from - 1,
 611                                 oldmark, f1mark);
 612                 }
 613         }
 614         if (iflag)
 615                 printf("w\nq\n");
 616
 617         exit(eflag == EFLAG_NONE ? overlapcnt : 0);
 618 }
 619
 620 /*
 621  * Output an edit script to turn mine into yours, when there is a conflict
 622  * between the 3 files bracket the changes. Regurgitate the diffs in reverse
 623  * order to allow the ed script to track down where the lines are as changes
 624  * are made.
 625  */
 626 static void
 627 Ascript(int n)
 628 {
 629         int startmark;
 630         bool deletenew;
 631         bool deleteold;
 632
 633         for (; n > 0; n--) {
 634
 635                 deletenew = (de[n].new.from == de[n].new.to);
 636                 deleteold = (de[n].old.from == de[n].old.to);
 637                 startmark = de[n].old.from + (de[n].old.to - de[n].old.from) - 1;
 638
 639                 if (de[n].type == DIFF_TYPE2) {
 640                         if (!oflag || !overlap[n]) {
 641                                 prange(&de[n].old, deletenew);
 642                                 printrange(fp[2], &de[n].new);
 643                         } else {
 644                                 startmark = de[n].new.from +
 645                                         (de[n].new.to - de[n].new.from);
 646
 647                                 if (!deletenew)
 648                                         startmark--;
 649
 650                                 printf("%da\n", startmark);
 651                                 printf("%s %s\n", newmark, f3mark);
 652
 653                                 printf(".\n");
 654
 655                                 printf("%da\n", startmark -
 656                                         (de[n].new.to - de[n].new.from));
 657                                 printf("%s %s\n", oldmark, f2mark);
 658                                 if (!deleteold)
 659                                         printrange(fp[1], &de[n].old);
 660                                 printf("=======\n.\n");
 661                         }
 662
 663                 } else if (de[n].type == DIFF_TYPE3) {
 664                         if (!oflag || !overlap[n]) {
 665                                 prange(&de[n].old, deletenew);
 666                                 printrange(fp[2], &de[n].new);
 667                         } else {
 668                                 printf("%da\n", startmark);
 669                                 printf("%s %s\n", orgmark, f2mark);
 670
 671                                 if (deleteold) {
 672                                         struct range r;
 673                                         r.from = de[n].old.from-1;
 674                                         r.to = de[n].new.to;
 675                                         printrange(fp[1], &r);
 676                                 } else
 677                                         printrange(fp[1], &de[n].old);
 678
 679                                 printf("=======\n");
 680                                 printrange(fp[2], &de[n].new);
 681                         }
 682
 683                         if (!oflag || !overlap[n]) {
 684                                 if (!deletenew)
 685                                         printf(".\n");
 686                         } else {
 687                                 printf("%s %s\n.\n", newmark, f3mark);
 688
 689                                 /*
 690                                  * Go to the start of the conflict in original
 691                                  * file and append lines
 692                                  */
 693                                 printf("%da\n%s %s\n.\n",
 694                                         startmark - (de[n].old.to - de[n].old.from),
 695                                         oldmark, f1mark);
 696                         }
 697                 }
 698         }
 699         if (iflag)
 700                 printf("w\nq\n");
 701
 702         exit(overlapcnt > 0);
 703 }
 704
 705 /*
 706  * Output the merged file directly (don't generate an ed script). When
 707  * regurgitating diffs we need to walk forward through the file and print any
 708  * inbetween lines.
 709  */
 710 static void
 711 mergescript(int i)
 712 {
 713         struct range r;
 714         int n;
 715
 716         r.from = 1;
 717         r.to = 1;
 718
 719         for (n = 1; n < i+1; n++) {
 720                 /* print any lines leading up to here */
 721                 r.to = de[n].old.from;
 722                 printrange(fp[0], &r);
 723
 724                 if (de[n].type == DIFF_TYPE2) {
 725                         printf("%s %s\n", oldmark, f2mark);
 726                         printrange(fp[1], &de[n].old);
 727                         printf("=======\n");
 728                         printrange(fp[2], &de[n].new);
 729                         printf("%s %s\n", newmark, f3mark);
 730                 } else if (de[n].type == DIFF_TYPE3) {
 731                         if (!oflag || !overlap[n]) {
 732                                 printrange(fp[2], &de[n].new);
 733                         } else {
 734
 735                                 printf("%s %s\n", oldmark, f1mark);
 736                                 printrange(fp[0], &de[n].old);
 737
 738                                 printf("%s %s\n", orgmark, f2mark);
 739                                 if (de[n].old.from == de[n].old.to) {
 740                                         struct range or;
 741                                         or.from = de[n].old.from -1;
 742                                         or.to = de[n].new.to;
 743                                         printrange(fp[1], &or);
 744                                 } else
 745                                         printrange(fp[1], &de[n].old);
 746
 747                                 printf("=======\n");
 748
 749                                 printrange(fp[2], &de[n].new);
 750                                 printf("%s %s\n", newmark, f3mark);
 751                         }
 752                 }
 753
 754                 if (de[n].old.from == de[n].old.to)
 755                         r.from = de[n].new.to;
 756                 else
 757                         r.from = de[n].old.to;
 758         }
 759         /*
 760          * Print from the final range to the end of 'myfile'. Any deletions or
 761          * additions to this file should have been handled by now.
 762          *
 763          * If the ranges are the same we need to rewind a line.
 764          * If the new range is 0 length (from == to), we need to use the old
 765          * range.
 766          */
 767         if ((de[n-1].old.from == de[n-1].new.from) &&
 768                 (de[n-1].old.to == de[n-1].new.to))
 769                 r.from--;
 770         else if (de[n-1].new.from == de[n-1].new.to)
 771                 r.from = de[n-1].old.from;
 772
 773         /*
 774          * If the range is a 3 way merge then we need to skip a line in the
 775          * trailing output.
 776          */
 777         if (de[n-1].type == DIFF_TYPE3)
 778                 r.from++;
 779
 780         r.to = INT_MAX;
 781         printrange(fp[0], &r);
 782         exit(overlapcnt > 0);
 783 }
 784
 785 static void
 786 increase(void)
 787 {
 788         struct diff *p;
 789         char *q;
 790         size_t newsz, incr;
 791
 792         /* are the memset(3) calls needed? */
 793         newsz = szchanges == 0 ? 64 : 2 * szchanges;
 794         incr = newsz - szchanges;
 795
 796         p = reallocarray(d13, newsz, sizeof(struct diff));
 797         if (p == NULL)
 798                 err(1, NULL);
 799         memset(p + szchanges, 0, incr * sizeof(struct diff));
 800         d13 = p;
 801         p = reallocarray(d23, newsz, sizeof(struct diff));
 802         if (p == NULL)
 803                 err(1, NULL);
 804         memset(p + szchanges, 0, incr * sizeof(struct diff));
 805         d23 = p;
 806         p = reallocarray(de, newsz, sizeof(struct diff));
 807         if (p == NULL)
 808                 err(1, NULL);
 809         memset(p + szchanges, 0, incr * sizeof(struct diff));
 810         de = p;
 811         q = reallocarray(overlap, newsz, sizeof(char));
 812         if (q == NULL)
 813                 err(1, NULL);
 814         memset(q + szchanges, 0, incr * sizeof(char));
 815         overlap = q;
 816         szchanges = newsz;
 817 }
 818
 819
 820 int
 821 main(int argc, char **argv)
 822 {
 823         int ch, nblabels, status, m, n, kq, nke, nleft, i;
 824         char *labels[] = { NULL, NULL, NULL };
 825         const char *diffprog = DIFF_PATH;
 826         char *file1, *file2, *file3;
 827         char *diffargv[7];
 828         int diffargc = 0;
 829         int fd13[2], fd23[2];
 830         int pd13, pd23;
 831         cap_rights_t rights_ro;
 832         struct kevent *e;
 833
 834         nblabels = 0;
 835         eflag = EFLAG_NONE;
 836         oflag = 0;
 837         diffargv[diffargc++] = __DECONST(char *, diffprog);
 838         while ((ch = getopt_long(argc, argv, OPTIONS, longopts, NULL)) != -1) {
 839                 switch (ch) {
 840                 case '3':
 841                         eflag = EFLAG_NOOVERLAP;
 842                         break;
 843                 case 'a':
 844                         diffargv[diffargc++] = __DECONST(char *, "-a");
 845                         break;
 846                 case 'A':
 847                         Aflag = 1;
 848                         break;
 849                 case 'e':
 850                         eflag = EFLAG_UNMERGED;
 851                         break;
 852                 case 'E':
 853                         eflag = EFLAG_UNMERGED;
 854                         oflag = 1;
 855                         break;
 856                 case 'i':
 857                         iflag = 1;
 858                         break;
 859                 case 'L':
 860                         oflag = 1;
 861                         if (nblabels >= 3)
 862                                 errx(2, "too many file label options");
 863                         labels[nblabels++] = optarg;
 864                         break;
 865                 case 'm':
 866                         Aflag = 1;
 867                         oflag = 1;
 868                         mflag = 1;
 869                         break;
 870                 case 'T':
 871                         Tflag = 1;
 872                         break;
 873                 case 'x':
 874                         eflag = EFLAG_OVERLAP;
 875                         break;
 876                 case 'X':
 877                         oflag = 1;
 878                         eflag = EFLAG_OVERLAP;
 879                         break;
 880                 case DIFFPROG_OPT:
 881                         diffprog = optarg;
 882                         break;
 883                 case STRIPCR_OPT:
 884                         strip_cr = 1;
 885                         diffargv[diffargc++] = __DECONST(char *, "--strip-trailing-cr");
 886                         break;
 887                 case HELP_OPT:
 888                         usage();
 889                         exit(0);
 890                 case VERSION_OPT:
 891                         printf("%s\n", diff3_version);
 892                         exit(0);
 893                 }
 894         }
 895         argc -= optind;
 896         argv += optind;
 897
 898         if (Aflag) {
 899                 eflag = EFLAG_UNMERGED;
 900                 oflag = 1;
 901         }
 902
 903         if (argc != 3) {
 904                 usage();
 905                 exit(2);
 906         }
 907
 908         if (caph_limit_stdio() == -1)
 909                 err(2, "unable to limit stdio");
 910
 911         cap_rights_init(&rights_ro, CAP_READ, CAP_FSTAT, CAP_SEEK);
 912
 913         kq = kqueue();
 914         if (kq == -1)
 915                 err(2, "kqueue");
 916
 917         e = malloc(2 * sizeof(struct kevent));
 918         if (e == NULL)
 919                 err(2, "malloc");
 920
 921         /* TODO stdio */
 922         file1 = argv[0];
 923         file2 = argv[1];
 924         file3 = argv[2];
 925
 926         if (oflag) {
 927                 asprintf(&f1mark, "%s",
 928                     labels[0] != NULL ? labels[0] : file1);
 929                 if (f1mark == NULL)
 930                         err(2, "asprintf");
 931                 asprintf(&f2mark, "%s",
 932                     labels[1] != NULL ? labels[1] : file2);
 933                 if (f2mark == NULL)
 934                         err(2, "asprintf");
 935                 asprintf(&f3mark, "%s",
 936                     labels[2] != NULL ? labels[2] : file3);
 937                 if (f3mark == NULL)
 938                         err(2, "asprintf");
 939         }
 940         fp[0] = fopen(file1, "r");
 941         if (fp[0] == NULL)
 942                 err(2, "Can't open %s", file1);
 943         if (caph_rights_limit(fileno(fp[0]), &rights_ro) < 0)
 944                 err(2, "unable to limit rights on: %s", file1);
 945
 946         fp[1] = fopen(file2, "r");
 947         if (fp[1] == NULL)
 948                 err(2, "Can't open %s", file2);
 949         if (caph_rights_limit(fileno(fp[1]), &rights_ro) < 0)
 950                 err(2, "unable to limit rights on: %s", file2);
 951
 952         fp[2] = fopen(file3, "r");
 953         if (fp[2] == NULL)
 954                 err(2, "Can't open %s", file3);
 955         if (caph_rights_limit(fileno(fp[2]), &rights_ro) < 0)
 956                 err(2, "unable to limit rights on: %s", file3);
 957
 958         if (pipe(fd13))
 959                 err(2, "pipe");
 960         if (pipe(fd23))
 961                 err(2, "pipe");
 962
 963         diffargv[diffargc] = file1;
 964         diffargv[diffargc + 1] = file3;
 965         diffargv[diffargc + 2] = NULL;
 966
 967         nleft = 0;
 968         pd13 = diffexec(diffprog, diffargv, fd13);
 969         EV_SET(e + nleft , pd13, EVFILT_PROCDESC, EV_ADD, NOTE_EXIT, 0, NULL);
 970         if (kevent(kq, e + nleft, 1, NULL, 0, NULL) == -1)
 971                 err(2, "kevent1");
 972         nleft++;
 973
 974         diffargv[diffargc] = file2;
 975         pd23 = diffexec(diffprog, diffargv, fd23);
 976         EV_SET(e + nleft , pd23, EVFILT_PROCDESC, EV_ADD, NOTE_EXIT, 0, NULL);
 977         if (kevent(kq, e + nleft, 1, NULL, 0, NULL) == -1)
 978                 err(2, "kevent2");
 979         nleft++;
 980
 981         caph_cache_catpages();
 982         if (caph_enter() < 0)
 983                 err(2, "unable to enter capability mode");
 984
 985         /* parse diffs */
 986         increase();
 987         m = readin(fd13[0], &d13);
 988         n = readin(fd23[0], &d23);
 989
 990         /* waitpid cooked over pdforks */
 991         while (nleft > 0) {
 992                 nke = kevent(kq, NULL, 0, e, nleft, NULL);
 993                 if (nke == -1)
 994                         err(2, "kevent");
 995                 for (i = 0; i < nke; i++) {
 996                         status = e[i].data;
 997                         if (WIFEXITED(status) && WEXITSTATUS(status) >= 2)
 998                                 errx(2, "diff exited abnormally");
 999                         else if (WIFSIGNALED(status))
1000                                 errx(2, "diff killed by signal %d",
1001                                     WTERMSIG(status));
1002                 }
1003                 nleft -= nke;
1004         }
1005         merge(m, n);
1006
1007         return (EXIT_SUCCESS);
1008 }