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 static const char *divider = "=======";
 148
 149 static bool duplicate(struct range *, struct range *);
 150 static int edit(struct diff *, bool, int, int);
 151 static char *getchange(FILE *);
 152 static char *get_line(FILE *, size_t *);
 153 static int readin(int fd, struct diff **);
 154 static int skip(int, int, const char *);
 155 static void change(int, struct range *, bool);
 156 static void keep(int, struct range *);
 157 static void merge(int, int);
 158 static void prange(struct range *, bool);
 159 static void repos(int);
 160 static void edscript(int) __dead2;
 161 static void Ascript(int) __dead2;
 162 static void mergescript(int) __dead2;
 163 static void increase(void);
 164 static void usage(void);
 165 static void printrange(FILE *, struct range *);
 166
 167 static const char diff3_version[] = "FreeBSD diff3 20220517";
 168
 169 enum {
 170         DIFFPROG_OPT,
 171         STRIPCR_OPT,
 172         HELP_OPT,
 173         VERSION_OPT
 174 };
 175
 176 #define DIFF_PATH "/usr/bin/diff"
 177
 178 #define OPTIONS "3aAeEiL:mTxX"
 179 static struct option longopts[] = {
 180         { "ed",                 no_argument,            NULL,   'e' },
 181         { "show-overlap",       no_argument,            NULL,   'E' },
 182         { "overlap-only",       no_argument,            NULL,   'x' },
 183         { "initial-tab",        no_argument,            NULL,   'T' },
 184         { "text",               no_argument,            NULL,   'a' },
 185         { "strip-trailing-cr",  no_argument,            NULL,   STRIPCR_OPT },
 186         { "show-all",           no_argument,            NULL,   'A' },
 187         { "easy-only",          no_argument,            NULL,   '3' },
 188         { "merge",              no_argument,            NULL,   'm' },
 189         { "label",              required_argument,      NULL,   'L' },
 190         { "diff-program",       required_argument,      NULL,   DIFFPROG_OPT },
 191         { "help",               no_argument,            NULL,   HELP_OPT},
 192         { "version",            no_argument,            NULL,   VERSION_OPT}
 193 };
 194
 195 static void
 196 usage(void)
 197 {
 198         fprintf(stderr, "usage: diff3 [-3aAeEimTxX] [-L label1] [-L label2] "
 199             "[-L label3] file1 file2 file3\n");
 200 }
 201
 202 static int
 203 readin(int fd, struct diff **dd)
 204 {
 205         int a, b, c, d;
 206         size_t i;
 207         char kind, *p;
 208         FILE *f;
 209
 210         f = fdopen(fd, "r");
 211         if (f == NULL)
 212                 err(2, "fdopen");
 213         for (i = 0; (p = getchange(f)); i++) {
 214 #if DEBUG
 215                 (*dd)[i].line = strdup(p);
 216 #endif  /* DEBUG */
 217
 218                 if (i >= szchanges - 1)
 219                         increase();
 220                 a = b = (int)strtoimax(p, &p, 10);
 221                 if (*p == ',') {
 222                         p++;
 223                         b = (int)strtoimax(p, &p, 10);
 224                 }
 225                 kind = *p++;
 226                 c = d = (int)strtoimax(p, &p, 10);
 227                 if (*p == ',') {
 228                         p++;
 229                         d = (int)strtoimax(p, &p, 10);
 230                 }
 231                 if (kind == 'a')
 232                         a++;
 233                 if (kind == 'd')
 234                         c++;
 235                 b++;
 236                 d++;
 237                 (*dd)[i].old.from = a;
 238                 (*dd)[i].old.to = b;
 239                 (*dd)[i].new.from = c;
 240                 (*dd)[i].new.to = d;
 241         }
 242         if (i) {
 243                 (*dd)[i].old.from = (*dd)[i - 1].old.to;
 244                 (*dd)[i].new.from = (*dd)[i - 1].new.to;
 245         }
 246         fclose(f);
 247         return (i);
 248 }
 249
 250 static int
 251 diffexec(const char *diffprog, char **diffargv, int fd[])
 252 {
 253         int pd;
 254
 255         switch (pdfork(&pd, PD_CLOEXEC)) {
 256         case 0:
 257                 close(fd[0]);
 258                 if (dup2(fd[1], STDOUT_FILENO) == -1)
 259                         err(2, "child could not duplicate descriptor");
 260                 close(fd[1]);
 261                 execvp(diffprog, diffargv);
 262                 err(2, "could not execute diff: %s", diffprog);
 263                 break;
 264         case -1:
 265                 err(2, "could not fork");
 266                 break;
 267         }
 268         close(fd[1]);
 269         return (pd);
 270 }
 271
 272 static char *
 273 getchange(FILE *b)
 274 {
 275         char *line;
 276
 277         while ((line = get_line(b, NULL))) {
 278                 if (isdigit((unsigned char)line[0]))
 279                         return (line);
 280         }
 281         return (NULL);
 282 }
 283
 284
 285 static char *
 286 get_line(FILE *b, size_t *n)
 287 {
 288         ssize_t len;
 289         static char *buf = NULL;
 290         static size_t bufsize = 0;
 291
 292         if ((len = getline(&buf, &bufsize, b)) < 0)
 293                 return (NULL);
 294
 295         if (strip_cr && len >= 2 && strcmp("\r\n", &(buf[len - 2])) == 0) {
 296                 buf[len - 2] = '\n';
 297                 buf[len - 1] = '\0';
 298                 len--;
 299         }
 300
 301         if (n != NULL)
 302                 *n = len;
 303
 304         return (buf);
 305 }
 306
 307 static void
 308 merge(int m1, int m2)
 309 {
 310         struct diff *d1, *d2, *d3;
 311         int j, t1, t2;
 312         bool dup = false;
 313
 314         d1 = d13;
 315         d2 = d23;
 316         j = 0;
 317
 318         while (t1 = d1 < d13 + m1, t2 = d2 < d23 + m2, t1 || t2) {
 319                 /* first file is different from the others */
 320                 if (!t2 || (t1 && d1->new.to < d2->new.from)) {
 321                         /* stuff peculiar to 1st file */
 322                         if (eflag == EFLAG_NONE) {
 323                                 printf("====1\n");
 324                                 change(1, &d1->old, false);
 325                                 keep(2, &d1->new);
 326                                 change(3, &d1->new, false);
 327                         }
 328                         d1++;
 329                         continue;
 330                 }
 331                 /* second file is different from others */
 332                 if (!t1 || (t2 && d2->new.to < d1->new.from)) {
 333                         if (eflag == EFLAG_NONE) {
 334                                 printf("====2\n");
 335                                 keep(1, &d2->new);
 336                                 change(3, &d2->new, false);
 337                                 change(2, &d2->old, false);
 338                         } else if (Aflag || mflag) {
 339                                 // XXX-THJ: What does it mean for the second file to differ?
 340                                 j = edit(d2, dup, j, DIFF_TYPE2);
 341                         }
 342                         d2++;
 343                         continue;
 344                 }
 345                 /*
 346                  * Merge overlapping changes in first file
 347                  * this happens after extension (see below).
 348                  */
 349                 if (d1 + 1 < d13 + m1 && d1->new.to >= d1[1].new.from) {
 350                         d1[1].old.from = d1->old.from;
 351                         d1[1].new.from = d1->new.from;
 352                         d1++;
 353                         continue;
 354                 }
 355
 356                 /* merge overlapping changes in second */
 357                 if (d2 + 1 < d23 + m2 && d2->new.to >= d2[1].new.from) {
 358                         d2[1].old.from = d2->old.from;
 359                         d2[1].new.from = d2->new.from;
 360                         d2++;
 361                         continue;
 362                 }
 363                 /* stuff peculiar to third file or different in all */
 364                 if (d1->new.from == d2->new.from && d1->new.to == d2->new.to) {
 365                         dup = duplicate(&d1->old, &d2->old);
 366                         /*
 367                          * dup = 0 means all files differ
 368                          * dup = 1 means files 1 and 2 identical
 369                          */
 370                         if (eflag == EFLAG_NONE) {
 371                                 printf("====%s\n", dup ? "3" : "");
 372                                 change(1, &d1->old, dup);
 373                                 change(2, &d2->old, false);
 374                                 d3 = d1->old.to > d1->old.from ? d1 : d2;
 375                                 change(3, &d3->new, false);
 376                         } else {
 377                                 j = edit(d1, dup, j, DIFF_TYPE3);
 378                         }
 379                         dup = false;
 380                         d1++;
 381                         d2++;
 382                         continue;
 383                 }
 384                 /*
 385                  * Overlapping changes from file 1 and 2; extend changes
 386                  * appropriately to make them coincide.
 387                  */
 388                 if (d1->new.from < d2->new.from) {
 389                         d2->old.from -= d2->new.from - d1->new.from;
 390                         d2->new.from = d1->new.from;
 391                 } else if (d2->new.from < d1->new.from) {
 392                         d1->old.from -= d1->new.from - d2->new.from;
 393                         d1->new.from = d2->new.from;
 394                 }
 395                 if (d1->new.to > d2->new.to) {
 396                         d2->old.to += d1->new.to - d2->new.to;
 397                         d2->new.to = d1->new.to;
 398                 } else if (d2->new.to > d1->new.to) {
 399                         d1->old.to += d2->new.to - d1->new.to;
 400                         d1->new.to = d2->new.to;
 401                 }
 402         }
 403
 404         if (mflag)
 405                 mergescript(j);
 406         else if (Aflag)
 407                 Ascript(j);
 408         else if (eflag)
 409                 edscript(j);
 410 }
 411
 412 /*
 413  * The range of lines rold.from thru rold.to in file i is to be changed.
 414  * It is to be printed only if it does not duplicate something to be
 415  * printed later.
 416  */
 417 static void
 418 change(int i, struct range *rold, bool dup)
 419 {
 420
 421         printf("%d:", i);
 422         last[i] = rold->to;
 423         prange(rold, false);
 424         if (dup)
 425                 return;
 426         i--;
 427         skip(i, rold->from, NULL);
 428         skip(i, rold->to, "  ");
 429 }
 430
 431 /*
 432  * Print the range of line numbers, rold.from thru rold.to, as n1,n2 or
 433  * n1.
 434  */
 435 static void
 436 prange(struct range *rold, bool delete)
 437 {
 438
 439         if (rold->to <= rold->from)
 440                 printf("%da\n", rold->from - 1);
 441         else {
 442                 printf("%d", rold->from);
 443                 if (rold->to > rold->from + 1)
 444                         printf(",%d", rold->to - 1);
 445                 if (delete)
 446                         printf("d\n");
 447                 else
 448                         printf("c\n");
 449         }
 450 }
 451
 452 /*
 453  * No difference was reported by diff between file 1 (or 2) and file 3,
 454  * and an artificial dummy difference (trange) must be ginned up to
 455  * correspond to the change reported in the other file.
 456  */
 457 static void
 458 keep(int i, struct range *rnew)
 459 {
 460         int delta;
 461         struct range trange;
 462
 463         delta = last[3] - last[i];
 464         trange.from = rnew->from - delta;
 465         trange.to = rnew->to - delta;
 466         change(i, &trange, true);
 467 }
 468
 469 /*
 470  * skip to just before line number from in file "i".  If "pr" is non-NULL,
 471  * print all skipped stuff with string pr as a prefix.
 472  */
 473 static int
 474 skip(int i, int from, const char *pr)
 475 {
 476         size_t j, n;
 477         char *line;
 478
 479         for (n = 0; cline[i] < from - 1; n += j) {
 480                 if ((line = get_line(fp[i], &j)) == NULL)
 481                         errx(EXIT_FAILURE, "logic error");
 482                 if (pr != NULL)
 483                         printf("%s%s", Tflag == 1 ? "\t" : pr, line);
 484                 cline[i]++;
 485         }
 486         return ((int) n);
 487 }
 488
 489 /*
 490  * Return 1 or 0 according as the old range (in file 1) contains exactly
 491  * the same data as the new range (in file 2).
 492  */
 493 static bool
 494 duplicate(struct range *r1, struct range *r2)
 495 {
 496         int c, d;
 497         int nchar;
 498         int nline;
 499
 500         if (r1->to-r1->from != r2->to-r2->from)
 501                 return (0);
 502         skip(0, r1->from, NULL);
 503         skip(1, r2->from, NULL);
 504         nchar = 0;
 505         for (nline = 0; nline < r1->to - r1->from; nline++) {
 506                 do {
 507                         c = getc(fp[0]);
 508                         d = getc(fp[1]);
 509                         if (c == -1 && d == -1)
 510                                 break;
 511                         if (c == -1 || d == -1)
 512                                 errx(EXIT_FAILURE, "logic error");
 513                         nchar++;
 514                         if (c != d) {
 515                                 repos(nchar);
 516                                 return (0);
 517                         }
 518                 } while (c != '\n');
 519         }
 520         repos(nchar);
 521         return (1);
 522 }
 523
 524 static void
 525 repos(int nchar)
 526 {
 527         int i;
 528
 529         for (i = 0; i < 2; i++)
 530                 (void)fseek(fp[i], (long)-nchar, SEEK_CUR);
 531 }
 532
 533 /*
 534  * collect an editing script for later regurgitation
 535  */
 536 static int
 537 edit(struct diff *diff, bool dup, int j, int difftype)
 538 {
 539         if (!(eflag == EFLAG_UNMERGED ||
 540                 (!dup && eflag == EFLAG_OVERLAP ) ||
 541                 (dup && eflag == EFLAG_NOOVERLAP))) {
 542                 return (j);
 543         }
 544         j++;
 545         overlap[j] = !dup;
 546         if (!dup)
 547                 overlapcnt++;
 548
 549         de[j].type = difftype;
 550 #if DEBUG
 551         de[j].line = strdup(diff->line);
 552 #endif  /* DEBUG */
 553
 554         de[j].old.from = diff->old.from;
 555         de[j].old.to = diff->old.to;
 556         de[j].new.from = diff->new.from;
 557         de[j].new.to = diff->new.to;
 558         return (j);
 559 }
 560
 561 static void
 562 printrange(FILE *p, struct range *r)
 563 {
 564         char *line = NULL;
 565         size_t len = 0;
 566         int i = 1;
 567         ssize_t rlen = 0;
 568
 569         /* We haven't been asked to print anything */
 570         if (r->from == r->to)
 571                 return;
 572
 573         if (r->from > r->to)
 574                 errx(EXIT_FAILURE, "invalid print range");
 575
 576         /*
 577          * XXX-THJ: We read through all of the file for each range printed.
 578          * This duplicates work and will probably impact performance on large
 579          * files with lots of ranges.
 580          */
 581         fseek(p, 0L, SEEK_SET);
 582         while ((rlen = getline(&line, &len, p)) > 0) {
 583                 if (i >= r->from)
 584                         printf("%s", line);
 585                 if (++i > r->to - 1)
 586                         break;
 587         }
 588         free(line);
 589 }
 590
 591 /* regurgitate */
 592 static void
 593 edscript(int n)
 594 {
 595         bool delete;
 596         struct range *new, *old;
 597
 598         for (; n > 0; n--) {
 599                 new = &de[n].new;
 600                 old = &de[n].old;
 601
 602                 delete = (new->from == new->to);
 603                 if (!oflag || !overlap[n]) {
 604                         prange(old, delete);
 605                 } else {
 606                         printf("%da\n", old->to - 1);
 607                         printf("%s\n", divider);
 608                 }
 609                 printrange(fp[2], new);
 610                 if (!oflag || !overlap[n]) {
 611                         if (!delete)
 612                                 printf(".\n");
 613                 } else {
 614                         printf("%s %s\n.\n", newmark, f3mark);
 615                         printf("%da\n%s %s\n.\n", old->from - 1,
 616                                 oldmark, f1mark);
 617                 }
 618         }
 619         if (iflag)
 620                 printf("w\nq\n");
 621
 622         exit(eflag == EFLAG_NONE ? overlapcnt : 0);
 623 }
 624
 625 /*
 626  * Output an edit script to turn mine into yours, when there is a conflict
 627  * between the 3 files bracket the changes. Regurgitate the diffs in reverse
 628  * order to allow the ed script to track down where the lines are as changes
 629  * are made.
 630  */
 631 static void
 632 Ascript(int n)
 633 {
 634         int startmark;
 635         bool deletenew;
 636         bool deleteold;
 637
 638         struct range *new, *old;
 639
 640         for (; n > 0; n--) {
 641                 new = &de[n].new;
 642                 old = &de[n].old;
 643                 deletenew = (new->from == new->to);
 644                 deleteold = (old->from == old->to);
 645
 646                 if (de[n].type == DIFF_TYPE2) {
 647                         if (!oflag || !overlap[n]) {
 648                                 prange(old, deletenew);
 649                                 printrange(fp[2], new);
 650                         } else {
 651                                 startmark = new->to;
 652
 653                                 if (!deletenew)
 654                                         startmark--;
 655
 656                                 printf("%da\n", startmark);
 657                                 printf("%s %s\n", newmark, f3mark);
 658
 659                                 printf(".\n");
 660
 661                                 printf("%da\n", startmark -
 662                                         (new->to - new->from));
 663                                 printf("%s %s\n", oldmark, f2mark);
 664                                 if (!deleteold)
 665                                         printrange(fp[1], old);
 666                                 printf("%s\n.\n", divider);
 667                         }
 668
 669                 } else if (de[n].type == DIFF_TYPE3) {
 670                         startmark = old->to - 1;
 671
 672                         if (!oflag || !overlap[n]) {
 673                                 prange(old, deletenew);
 674                                 printrange(fp[2], new);
 675                         } else {
 676                                 printf("%da\n", startmark);
 677                                 printf("%s %s\n", orgmark, f2mark);
 678
 679                                 if (deleteold) {
 680                                         struct range r;
 681                                         r.from = old->from-1;
 682                                         r.to = new->to;
 683                                         printrange(fp[1], &r);
 684                                 } else
 685                                         printrange(fp[1], old);
 686
 687                                 printf("%s\n", divider);
 688                                 printrange(fp[2], new);
 689                         }
 690
 691                         if (!oflag || !overlap[n]) {
 692                                 if (!deletenew)
 693                                         printf(".\n");
 694                         } else {
 695                                 printf("%s %s\n.\n", newmark, f3mark);
 696
 697                                 /*
 698                                  * Go to the start of the conflict in original
 699                                  * file and append lines
 700                                  */
 701                                 printf("%da\n%s %s\n.\n",
 702                                         startmark - (old->to - old->from),
 703                                         oldmark, f1mark);
 704                         }
 705                 }
 706         }
 707         if (iflag)
 708                 printf("w\nq\n");
 709
 710         exit(overlapcnt > 0);
 711 }
 712
 713 /*
 714  * Output the merged file directly (don't generate an ed script). When
 715  * regurgitating diffs we need to walk forward through the file and print any
 716  * inbetween lines.
 717  */
 718 static void
 719 mergescript(int i)
 720 {
 721         struct range r, *new, *old;
 722         int n;
 723
 724         r.from = 1;
 725         r.to = 1;
 726
 727         for (n = 1; n < i+1; n++) {
 728                 new = &de[n].new;
 729                 old = &de[n].old;
 730
 731                 /* print any lines leading up to here */
 732                 r.to = old->from;
 733                 printrange(fp[0], &r);
 734
 735                 if (de[n].type == DIFF_TYPE2) {
 736                         printf("%s %s\n", oldmark, f2mark);
 737                         printrange(fp[1], old);
 738                         printf("%s\n", divider);
 739                         printrange(fp[2], new);
 740                         printf("%s %s\n", newmark, f3mark);
 741                 } else if (de[n].type == DIFF_TYPE3) {
 742                         if (!oflag || !overlap[n]) {
 743                                 printrange(fp[2], new);
 744                         } else {
 745
 746                                 printf("%s %s\n", oldmark, f1mark);
 747                                 printrange(fp[0], old);
 748
 749                                 printf("%s %s\n", orgmark, f2mark);
 750                                 if (old->from == old->to) {
 751                                         struct range or;
 752                                         or.from = old->from - 1;
 753                                         or.to = new->to;
 754                                         printrange(fp[1], &or);
 755                                 } else
 756                                         printrange(fp[1], old);
 757
 758                                 printf("%s\n", divider);
 759
 760                                 printrange(fp[2], new);
 761                                 printf("%s %s\n", newmark, f3mark);
 762                         }
 763                 }
 764
 765                 if (old->from == old->to)
 766                         r.from = new->to;
 767                 else
 768                         r.from = old->to;
 769         }
 770         /*
 771          * Print from the final range to the end of 'myfile'. Any deletions or
 772          * additions to this file should have been handled by now.
 773          *
 774          * If the ranges are the same we need to rewind a line.
 775          * If the new range is 0 length (from == to), we need to use the old
 776          * range.
 777          */
 778         new = &de[n-1].new;
 779         old = &de[n-1].old;
 780         if ((old->from == new->from) &&
 781                 (old->to == new->to))
 782                 r.from--;
 783         else if (new->from == new->to)
 784                 r.from = old->from;
 785
 786         /*
 787          * If the range is a 3 way merge then we need to skip a line in the
 788          * trailing output.
 789          */
 790         if (de[n-1].type == DIFF_TYPE3)
 791                 r.from++;
 792
 793         r.to = INT_MAX;
 794         printrange(fp[0], &r);
 795         exit(overlapcnt > 0);
 796 }
 797
 798 static void
 799 increase(void)
 800 {
 801         struct diff *p;
 802         char *q;
 803         size_t newsz, incr;
 804
 805         /* are the memset(3) calls needed? */
 806         newsz = szchanges == 0 ? 64 : 2 * szchanges;
 807         incr = newsz - szchanges;
 808
 809         p = reallocarray(d13, newsz, sizeof(struct diff));
 810         if (p == NULL)
 811                 err(1, NULL);
 812         memset(p + szchanges, 0, incr * sizeof(struct diff));
 813         d13 = p;
 814         p = reallocarray(d23, newsz, sizeof(struct diff));
 815         if (p == NULL)
 816                 err(1, NULL);
 817         memset(p + szchanges, 0, incr * sizeof(struct diff));
 818         d23 = p;
 819         p = reallocarray(de, newsz, sizeof(struct diff));
 820         if (p == NULL)
 821                 err(1, NULL);
 822         memset(p + szchanges, 0, incr * sizeof(struct diff));
 823         de = p;
 824         q = reallocarray(overlap, newsz, sizeof(char));
 825         if (q == NULL)
 826                 err(1, NULL);
 827         memset(q + szchanges, 0, incr * sizeof(char));
 828         overlap = q;
 829         szchanges = newsz;
 830 }
 831
 832
 833 int
 834 main(int argc, char **argv)
 835 {
 836         int ch, nblabels, status, m, n, kq, nke, nleft, i;
 837         char *labels[] = { NULL, NULL, NULL };
 838         const char *diffprog = DIFF_PATH;
 839         char *file1, *file2, *file3;
 840         char *diffargv[7];
 841         int diffargc = 0;
 842         int fd13[2], fd23[2];
 843         int pd13, pd23;
 844         cap_rights_t rights_ro;
 845         struct kevent *e;
 846
 847         nblabels = 0;
 848         eflag = EFLAG_NONE;
 849         oflag = 0;
 850         diffargv[diffargc++] = __DECONST(char *, diffprog);
 851         while ((ch = getopt_long(argc, argv, OPTIONS, longopts, NULL)) != -1) {
 852                 switch (ch) {
 853                 case '3':
 854                         eflag = EFLAG_NOOVERLAP;
 855                         break;
 856                 case 'a':
 857                         diffargv[diffargc++] = __DECONST(char *, "-a");
 858                         break;
 859                 case 'A':
 860                         Aflag = 1;
 861                         break;
 862                 case 'e':
 863                         eflag = EFLAG_UNMERGED;
 864                         break;
 865                 case 'E':
 866                         eflag = EFLAG_UNMERGED;
 867                         oflag = 1;
 868                         break;
 869                 case 'i':
 870                         iflag = 1;
 871                         break;
 872                 case 'L':
 873                         oflag = 1;
 874                         if (nblabels >= 3)
 875                                 errx(2, "too many file label options");
 876                         labels[nblabels++] = optarg;
 877                         break;
 878                 case 'm':
 879                         Aflag = 1;
 880                         oflag = 1;
 881                         mflag = 1;
 882                         break;
 883                 case 'T':
 884                         Tflag = 1;
 885                         break;
 886                 case 'x':
 887                         eflag = EFLAG_OVERLAP;
 888                         break;
 889                 case 'X':
 890                         oflag = 1;
 891                         eflag = EFLAG_OVERLAP;
 892                         break;
 893                 case DIFFPROG_OPT:
 894                         diffprog = optarg;
 895                         break;
 896                 case STRIPCR_OPT:
 897                         strip_cr = 1;
 898                         diffargv[diffargc++] = __DECONST(char *, "--strip-trailing-cr");
 899                         break;
 900                 case HELP_OPT:
 901                         usage();
 902                         exit(0);
 903                 case VERSION_OPT:
 904                         printf("%s\n", diff3_version);
 905                         exit(0);
 906                 }
 907         }
 908         argc -= optind;
 909         argv += optind;
 910
 911         if (Aflag) {
 912                 eflag = EFLAG_UNMERGED;
 913                 oflag = 1;
 914         }
 915
 916         if (argc != 3) {
 917                 usage();
 918                 exit(2);
 919         }
 920
 921         if (caph_limit_stdio() == -1)
 922                 err(2, "unable to limit stdio");
 923
 924         cap_rights_init(&rights_ro, CAP_READ, CAP_FSTAT, CAP_SEEK);
 925
 926         kq = kqueue();
 927         if (kq == -1)
 928                 err(2, "kqueue");
 929
 930         e = malloc(2 * sizeof(struct kevent));
 931         if (e == NULL)
 932                 err(2, "malloc");
 933
 934         /* TODO stdio */
 935         file1 = argv[0];
 936         file2 = argv[1];
 937         file3 = argv[2];
 938
 939         if (oflag) {
 940                 asprintf(&f1mark, "%s",
 941                     labels[0] != NULL ? labels[0] : file1);
 942                 if (f1mark == NULL)
 943                         err(2, "asprintf");
 944                 asprintf(&f2mark, "%s",
 945                     labels[1] != NULL ? labels[1] : file2);
 946                 if (f2mark == NULL)
 947                         err(2, "asprintf");
 948                 asprintf(&f3mark, "%s",
 949                     labels[2] != NULL ? labels[2] : file3);
 950                 if (f3mark == NULL)
 951                         err(2, "asprintf");
 952         }
 953         fp[0] = fopen(file1, "r");
 954         if (fp[0] == NULL)
 955                 err(2, "Can't open %s", file1);
 956         if (caph_rights_limit(fileno(fp[0]), &rights_ro) < 0)
 957                 err(2, "unable to limit rights on: %s", file1);
 958
 959         fp[1] = fopen(file2, "r");
 960         if (fp[1] == NULL)
 961                 err(2, "Can't open %s", file2);
 962         if (caph_rights_limit(fileno(fp[1]), &rights_ro) < 0)
 963                 err(2, "unable to limit rights on: %s", file2);
 964
 965         fp[2] = fopen(file3, "r");
 966         if (fp[2] == NULL)
 967                 err(2, "Can't open %s", file3);
 968         if (caph_rights_limit(fileno(fp[2]), &rights_ro) < 0)
 969                 err(2, "unable to limit rights on: %s", file3);
 970
 971         if (pipe(fd13))
 972                 err(2, "pipe");
 973         if (pipe(fd23))
 974                 err(2, "pipe");
 975
 976         diffargv[diffargc] = file1;
 977         diffargv[diffargc + 1] = file3;
 978         diffargv[diffargc + 2] = NULL;
 979
 980         nleft = 0;
 981         pd13 = diffexec(diffprog, diffargv, fd13);
 982         EV_SET(e + nleft , pd13, EVFILT_PROCDESC, EV_ADD, NOTE_EXIT, 0, NULL);
 983         if (kevent(kq, e + nleft, 1, NULL, 0, NULL) == -1)
 984                 err(2, "kevent1");
 985         nleft++;
 986
 987         diffargv[diffargc] = file2;
 988         pd23 = diffexec(diffprog, diffargv, fd23);
 989         EV_SET(e + nleft , pd23, EVFILT_PROCDESC, EV_ADD, NOTE_EXIT, 0, NULL);
 990         if (kevent(kq, e + nleft, 1, NULL, 0, NULL) == -1)
 991                 err(2, "kevent2");
 992         nleft++;
 993
 994         caph_cache_catpages();
 995         if (caph_enter() < 0)
 996                 err(2, "unable to enter capability mode");
 997
 998         /* parse diffs */
 999         increase();
1000         m = readin(fd13[0], &d13);
1001         n = readin(fd23[0], &d23);
1002
1003         /* waitpid cooked over pdforks */
1004         while (nleft > 0) {
1005                 nke = kevent(kq, NULL, 0, e, nleft, NULL);
1006                 if (nke == -1)
1007                         err(2, "kevent");
1008                 for (i = 0; i < nke; i++) {
1009                         status = e[i].data;
1010                         if (WIFEXITED(status) && WEXITSTATUS(status) >= 2)
1011                                 errx(2, "diff exited abnormally");
1012                         else if (WIFSIGNALED(status))
1013                                 errx(2, "diff killed by signal %d",
1014                                     WTERMSIG(status));
1015                 }
1016                 nleft -= nke;
1017         }
1018         merge(m, n);
1019
1020         return (EXIT_SUCCESS);
1021 }