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 #include <sys/capsicum.h>
  74 #include <sys/procdesc.h>
  75 #include <sys/types.h>
  76 #include <sys/event.h>
  77 #include <sys/wait.h>
  78
  79 #include <capsicum_helpers.h>
  80 #include <ctype.h>
  81 #include <err.h>
  82 #include <getopt.h>
  83 #include <stdio.h>
  84 #include <stdlib.h>
  85 #include <limits.h>
  86 #include <inttypes.h>
  87 #include <string.h>
  88 #include <unistd.h>
  89
  90
  91 /*
  92  * "from" is first in range of changed lines; "to" is last+1
  93  * from=to=line after point of insertion for added lines.
  94  */
  95 struct range {
  96         int from;
  97         int to;
  98 };
  99
 100 struct diff {
 101 #define DIFF_TYPE2 2
 102 #define DIFF_TYPE3 3
 103         int type;
 104 #if DEBUG
 105         char *line;
 106 #endif  /* DEBUG */
 107
 108         /* Ranges as lines */
 109         struct range old;
 110         struct range new;
 111 };
 112
 113 #define EFLAG_NONE      0
 114 #define EFLAG_OVERLAP   1
 115 #define EFLAG_NOOVERLAP 2
 116 #define EFLAG_UNMERGED  3
 117
 118 static size_t szchanges;
 119
 120 static struct diff *d13;
 121 static struct diff *d23;
 122 /*
 123  * "de" is used to gather editing scripts.  These are later spewed out in
 124  * reverse order.  Its first element must be all zero, the "old" and "new"
 125  * components of "de" contain line positions. Array overlap indicates which
 126  * sections in "de" correspond to lines that are different in all three files.
 127  */
 128 static struct diff *de;
 129 static char *overlap;
 130 static int  overlapcnt;
 131 static FILE *fp[3];
 132 static int cline[3];            /* # of the last-read line in each file (0-2) */
 133 /*
 134  * The latest known correspondence between line numbers of the 3 files
 135  * is stored in last[1-3];
 136  */
 137 static int last[4];
 138 static int Aflag, eflag, iflag, mflag, Tflag;
 139 static int oflag;               /* indicates whether to mark overlaps (-E or -X) */
 140 static int strip_cr;
 141 static char *f1mark, *f2mark, *f3mark;
 142 static const char *oldmark = "<<<<<<<";
 143 static const char *orgmark = "|||||||";
 144 static const char *newmark = ">>>>>>>";
 145 static const char *divider = "=======";
 146
 147 static bool duplicate(struct range *, struct range *);
 148 static int edit(struct diff *, bool, int, int);
 149 static char *getchange(FILE *);
 150 static char *get_line(FILE *, size_t *);
 151 static int readin(int fd, struct diff **);
 152 static int skip(int, int, const char *);
 153 static void change(int, struct range *, bool);
 154 static void keep(int, struct range *);
 155 static void merge(int, int);
 156 static void prange(struct range *, bool);
 157 static void repos(int);
 158 static void edscript(int) __dead2;
 159 static void Ascript(int) __dead2;
 160 static void mergescript(int) __dead2;
 161 static void increase(void);
 162 static void usage(void);
 163 static void printrange(FILE *, struct range *);
 164
 165 static const char diff3_version[] = "FreeBSD diff3 20220517";
 166
 167 enum {
 168         DIFFPROG_OPT,
 169         STRIPCR_OPT,
 170         HELP_OPT,
 171         VERSION_OPT
 172 };
 173
 174 #define DIFF_PATH "/usr/bin/diff"
 175
 176 #define OPTIONS "3aAeEiL:mTxX"
 177 static struct option longopts[] = {
 178         { "ed",                 no_argument,            NULL,   'e' },
 179         { "show-overlap",       no_argument,            NULL,   'E' },
 180         { "overlap-only",       no_argument,            NULL,   'x' },
 181         { "initial-tab",        no_argument,            NULL,   'T' },
 182         { "text",               no_argument,            NULL,   'a' },
 183         { "strip-trailing-cr",  no_argument,            NULL,   STRIPCR_OPT },
 184         { "show-all",           no_argument,            NULL,   'A' },
 185         { "easy-only",          no_argument,            NULL,   '3' },
 186         { "merge",              no_argument,            NULL,   'm' },
 187         { "label",              required_argument,      NULL,   'L' },
 188         { "diff-program",       required_argument,      NULL,   DIFFPROG_OPT },
 189         { "help",               no_argument,            NULL,   HELP_OPT},
 190         { "version",            no_argument,            NULL,   VERSION_OPT}
 191 };
 192
 193 static void
 194 usage(void)
 195 {
 196         fprintf(stderr, "usage: diff3 [-3aAeEimTxX] [-L label1] [-L label2] "
 197             "[-L label3] file1 file2 file3\n");
 198 }
 199
 200 static int
 201 readin(int fd, struct diff **dd)
 202 {
 203         int a, b, c, d;
 204         size_t i;
 205         char kind, *p;
 206         FILE *f;
 207
 208         f = fdopen(fd, "r");
 209         if (f == NULL)
 210                 err(2, "fdopen");
 211         for (i = 0; (p = getchange(f)); i++) {
 212 #if DEBUG
 213                 (*dd)[i].line = strdup(p);
 214 #endif  /* DEBUG */
 215
 216                 if (i >= szchanges - 1)
 217                         increase();
 218                 a = b = (int)strtoimax(p, &p, 10);
 219                 if (*p == ',') {
 220                         p++;
 221                         b = (int)strtoimax(p, &p, 10);
 222                 }
 223                 kind = *p++;
 224                 c = d = (int)strtoimax(p, &p, 10);
 225                 if (*p == ',') {
 226                         p++;
 227                         d = (int)strtoimax(p, &p, 10);
 228                 }
 229                 if (kind == 'a')
 230                         a++;
 231                 if (kind == 'd')
 232                         c++;
 233                 b++;
 234                 d++;
 235                 (*dd)[i].old.from = a;
 236                 (*dd)[i].old.to = b;
 237                 (*dd)[i].new.from = c;
 238                 (*dd)[i].new.to = d;
 239         }
 240         if (i) {
 241                 (*dd)[i].old.from = (*dd)[i - 1].old.to;
 242                 (*dd)[i].new.from = (*dd)[i - 1].new.to;
 243         }
 244         fclose(f);
 245         return (i);
 246 }
 247
 248 static int
 249 diffexec(const char *diffprog, char **diffargv, int fd[])
 250 {
 251         int pd;
 252
 253         switch (pdfork(&pd, PD_CLOEXEC)) {
 254         case 0:
 255                 close(fd[0]);
 256                 if (dup2(fd[1], STDOUT_FILENO) == -1)
 257                         err(2, "child could not duplicate descriptor");
 258                 close(fd[1]);
 259                 execvp(diffprog, diffargv);
 260                 err(2, "could not execute diff: %s", diffprog);
 261                 break;
 262         case -1:
 263                 err(2, "could not fork");
 264                 break;
 265         }
 266         close(fd[1]);
 267         return (pd);
 268 }
 269
 270 static char *
 271 getchange(FILE *b)
 272 {
 273         char *line;
 274
 275         while ((line = get_line(b, NULL))) {
 276                 if (isdigit((unsigned char)line[0]))
 277                         return (line);
 278         }
 279         return (NULL);
 280 }
 281
 282
 283 static char *
 284 get_line(FILE *b, size_t *n)
 285 {
 286         ssize_t len;
 287         static char *buf = NULL;
 288         static size_t bufsize = 0;
 289
 290         if ((len = getline(&buf, &bufsize, b)) < 0)
 291                 return (NULL);
 292
 293         if (strip_cr && len >= 2 && strcmp("\r\n", &(buf[len - 2])) == 0) {
 294                 buf[len - 2] = '\n';
 295                 buf[len - 1] = '\0';
 296                 len--;
 297         }
 298
 299         if (n != NULL)
 300                 *n = len;
 301
 302         return (buf);
 303 }
 304
 305 static void
 306 merge(int m1, int m2)
 307 {
 308         struct diff *d1, *d2, *d3;
 309         int j, t1, t2;
 310         bool dup = false;
 311
 312         d1 = d13;
 313         d2 = d23;
 314         j = 0;
 315
 316         while (t1 = d1 < d13 + m1, t2 = d2 < d23 + m2, t1 || t2) {
 317                 /* first file is different from the others */
 318                 if (!t2 || (t1 && d1->new.to < d2->new.from)) {
 319                         /* stuff peculiar to 1st file */
 320                         if (eflag == EFLAG_NONE) {
 321                                 printf("====1\n");
 322                                 change(1, &d1->old, false);
 323                                 keep(2, &d1->new);
 324                                 change(3, &d1->new, false);
 325                         }
 326                         d1++;
 327                         continue;
 328                 }
 329                 /* second file is different from others */
 330                 if (!t1 || (t2 && d2->new.to < d1->new.from)) {
 331                         if (eflag == EFLAG_NONE) {
 332                                 printf("====2\n");
 333                                 keep(1, &d2->new);
 334                                 change(3, &d2->new, false);
 335                                 change(2, &d2->old, false);
 336                         } else if (Aflag || mflag) {
 337                                 // XXX-THJ: What does it mean for the second file to differ?
 338                                 if (eflag == EFLAG_UNMERGED)
 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         struct range *new, *old;
 596
 597         for (; n > 0; n--) {
 598                 new = &de[n].new;
 599                 old = &de[n].old;
 600
 601                 delete = (new->from == new->to);
 602                 if (!oflag || !overlap[n]) {
 603                         prange(old, delete);
 604                 } else {
 605                         printf("%da\n", old->to - 1);
 606                         printf("%s\n", divider);
 607                 }
 608                 printrange(fp[2], new);
 609                 if (!oflag || !overlap[n]) {
 610                         if (!delete)
 611                                 printf(".\n");
 612                 } else {
 613                         printf("%s %s\n.\n", newmark, f3mark);
 614                         printf("%da\n%s %s\n.\n", old->from - 1,
 615                                 oldmark, f1mark);
 616                 }
 617         }
 618         if (iflag)
 619                 printf("w\nq\n");
 620
 621         exit(eflag == EFLAG_NONE ? overlapcnt : 0);
 622 }
 623
 624 /*
 625  * Output an edit script to turn mine into yours, when there is a conflict
 626  * between the 3 files bracket the changes. Regurgitate the diffs in reverse
 627  * order to allow the ed script to track down where the lines are as changes
 628  * are made.
 629  */
 630 static void
 631 Ascript(int n)
 632 {
 633         int startmark;
 634         bool deletenew;
 635         bool deleteold;
 636
 637         struct range *new, *old;
 638
 639         for (; n > 0; n--) {
 640                 new = &de[n].new;
 641                 old = &de[n].old;
 642                 deletenew = (new->from == new->to);
 643                 deleteold = (old->from == old->to);
 644
 645                 if (de[n].type == DIFF_TYPE2) {
 646                         if (!oflag || !overlap[n]) {
 647                                 prange(old, deletenew);
 648                                 printrange(fp[2], new);
 649                         } else {
 650                                 startmark = new->to;
 651
 652                                 if (!deletenew)
 653                                         startmark--;
 654
 655                                 printf("%da\n", startmark);
 656                                 printf("%s %s\n", newmark, f3mark);
 657
 658                                 printf(".\n");
 659
 660                                 printf("%da\n", startmark -
 661                                         (new->to - new->from));
 662                                 printf("%s %s\n", oldmark, f2mark);
 663                                 if (!deleteold)
 664                                         printrange(fp[1], old);
 665                                 printf("%s\n.\n", divider);
 666                         }
 667
 668                 } else if (de[n].type == DIFF_TYPE3) {
 669                         startmark = old->to - 1;
 670
 671                         if (!oflag || !overlap[n]) {
 672                                 prange(old, deletenew);
 673                                 printrange(fp[2], new);
 674                         } else {
 675                                 printf("%da\n", startmark);
 676                                 printf("%s %s\n", orgmark, f2mark);
 677
 678                                 if (deleteold) {
 679                                         struct range r;
 680                                         r.from = old->from-1;
 681                                         r.to = new->to;
 682                                         printrange(fp[1], &r);
 683                                 } else
 684                                         printrange(fp[1], old);
 685
 686                                 printf("%s\n", divider);
 687                                 printrange(fp[2], new);
 688                         }
 689
 690                         if (!oflag || !overlap[n]) {
 691                                 if (!deletenew)
 692                                         printf(".\n");
 693                         } else {
 694                                 printf("%s %s\n.\n", newmark, f3mark);
 695
 696                                 /*
 697                                  * Go to the start of the conflict in original
 698                                  * file and append lines
 699                                  */
 700                                 printf("%da\n%s %s\n.\n",
 701                                         startmark - (old->to - old->from),
 702                                         oldmark, f1mark);
 703                         }
 704                 }
 705         }
 706         if (iflag)
 707                 printf("w\nq\n");
 708
 709         exit(overlapcnt > 0);
 710 }
 711
 712 /*
 713  * Output the merged file directly (don't generate an ed script). When
 714  * regurgitating diffs we need to walk forward through the file and print any
 715  * inbetween lines.
 716  */
 717 static void
 718 mergescript(int i)
 719 {
 720         struct range r, *new, *old;
 721         int n;
 722
 723         r.from = 1;
 724         r.to = 1;
 725
 726         for (n = 1; n < i+1; n++) {
 727                 new = &de[n].new;
 728                 old = &de[n].old;
 729
 730                 /* print any lines leading up to here */
 731                 r.to = old->from;
 732                 printrange(fp[0], &r);
 733
 734                 if (de[n].type == DIFF_TYPE2) {
 735                         printf("%s %s\n", oldmark, f2mark);
 736                         printrange(fp[1], old);
 737                         printf("%s\n", divider);
 738                         printrange(fp[2], new);
 739                         printf("%s %s\n", newmark, f3mark);
 740                 } else if (de[n].type == DIFF_TYPE3) {
 741                         if (!oflag || !overlap[n]) {
 742                                 printrange(fp[2], new);
 743                         } else {
 744
 745                                 printf("%s %s\n", oldmark, f1mark);
 746                                 printrange(fp[0], old);
 747
 748                                 printf("%s %s\n", orgmark, f2mark);
 749                                 if (old->from == old->to) {
 750                                         struct range or;
 751                                         or.from = old->from - 1;
 752                                         or.to = new->to;
 753                                         printrange(fp[1], &or);
 754                                 } else
 755                                         printrange(fp[1], old);
 756
 757                                 printf("%s\n", divider);
 758
 759                                 printrange(fp[2], new);
 760                                 printf("%s %s\n", newmark, f3mark);
 761                         }
 762                 }
 763
 764                 if (old->from == old->to)
 765                         r.from = new->to;
 766                 else
 767                         r.from = old->to;
 768         }
 769         /*
 770          * Print from the final range to the end of 'myfile'. Any deletions or
 771          * additions to this file should have been handled by now.
 772          *
 773          * If the ranges are the same we need to rewind a line.
 774          * If the new range is 0 length (from == to), we need to use the old
 775          * range.
 776          */
 777         new = &de[n-1].new;
 778         old = &de[n-1].old;
 779         if ((old->from == new->from) &&
 780                 (old->to == new->to))
 781                 r.from--;
 782         else if (new->from == new->to)
 783                 r.from = old->from;
 784
 785         /*
 786          * If the range is a 3 way merge then we need to skip a line in the
 787          * trailing output.
 788          */
 789         if (de[n-1].type == DIFF_TYPE3)
 790                 r.from++;
 791
 792         r.to = INT_MAX;
 793         printrange(fp[0], &r);
 794         exit(overlapcnt > 0);
 795 }
 796
 797 static void
 798 increase(void)
 799 {
 800         struct diff *p;
 801         char *q;
 802         size_t newsz, incr;
 803
 804         /* are the memset(3) calls needed? */
 805         newsz = szchanges == 0 ? 64 : 2 * szchanges;
 806         incr = newsz - szchanges;
 807
 808         p = reallocarray(d13, newsz, sizeof(struct diff));
 809         if (p == NULL)
 810                 err(1, NULL);
 811         memset(p + szchanges, 0, incr * sizeof(struct diff));
 812         d13 = p;
 813         p = reallocarray(d23, newsz, sizeof(struct diff));
 814         if (p == NULL)
 815                 err(1, NULL);
 816         memset(p + szchanges, 0, incr * sizeof(struct diff));
 817         d23 = p;
 818         p = reallocarray(de, newsz, sizeof(struct diff));
 819         if (p == NULL)
 820                 err(1, NULL);
 821         memset(p + szchanges, 0, incr * sizeof(struct diff));
 822         de = p;
 823         q = reallocarray(overlap, newsz, sizeof(char));
 824         if (q == NULL)
 825                 err(1, NULL);
 826         memset(q + szchanges, 0, incr * sizeof(char));
 827         overlap = q;
 828         szchanges = newsz;
 829 }
 830
 831
 832 int
 833 main(int argc, char **argv)
 834 {
 835         int ch, nblabels, status, m, n, kq, nke, nleft, i;
 836         char *labels[] = { NULL, NULL, NULL };
 837         const char *diffprog = DIFF_PATH;
 838         char *file1, *file2, *file3;
 839         char *diffargv[7];
 840         int diffargc = 0;
 841         int fd13[2], fd23[2];
 842         int pd13, pd23;
 843         cap_rights_t rights_ro;
 844         struct kevent *e;
 845
 846         nblabels = 0;
 847         eflag = EFLAG_NONE;
 848         oflag = 0;
 849         diffargv[diffargc++] = __DECONST(char *, diffprog);
 850         while ((ch = getopt_long(argc, argv, OPTIONS, longopts, NULL)) != -1) {
 851                 switch (ch) {
 852                 case '3':
 853                         eflag = EFLAG_NOOVERLAP;
 854                         break;
 855                 case 'a':
 856                         diffargv[diffargc++] = __DECONST(char *, "-a");
 857                         break;
 858                 case 'A':
 859                         Aflag = 1;
 860                         break;
 861                 case 'e':
 862                         eflag = EFLAG_UNMERGED;
 863                         break;
 864                 case 'E':
 865                         eflag = EFLAG_OVERLAP;
 866                         oflag = 1;
 867                         break;
 868                 case 'i':
 869                         iflag = 1;
 870                         break;
 871                 case 'L':
 872                         oflag = 1;
 873                         if (nblabels >= 3)
 874                                 errx(2, "too many file label options");
 875                         labels[nblabels++] = optarg;
 876                         break;
 877                 case 'm':
 878                         Aflag = 1;
 879                         oflag = 1;
 880                         mflag = 1;
 881                         break;
 882                 case 'T':
 883                         Tflag = 1;
 884                         break;
 885                 case 'x':
 886                         eflag = EFLAG_OVERLAP;
 887                         break;
 888                 case 'X':
 889                         oflag = 1;
 890                         eflag = EFLAG_OVERLAP;
 891                         break;
 892                 case DIFFPROG_OPT:
 893                         diffprog = optarg;
 894                         break;
 895                 case STRIPCR_OPT:
 896                         strip_cr = 1;
 897                         diffargv[diffargc++] = __DECONST(char *, "--strip-trailing-cr");
 898                         break;
 899                 case HELP_OPT:
 900                         usage();
 901                         exit(0);
 902                 case VERSION_OPT:
 903                         printf("%s\n", diff3_version);
 904                         exit(0);
 905                 }
 906         }
 907         argc -= optind;
 908         argv += optind;
 909
 910         if (Aflag) {
 911                 if (eflag == EFLAG_NONE)
 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 }