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
  65 #include <sys/capsicum.h>
  66 #include <sys/procdesc.h>
  67 #include <sys/types.h>
  68 #include <sys/event.h>
  69 #include <sys/wait.h>
  70
  71 #include <capsicum_helpers.h>
  72 #include <ctype.h>
  73 #include <err.h>
  74 #include <getopt.h>
  75 #include <stdio.h>
  76 #include <stdlib.h>
  77 #include <limits.h>
  78 #include <inttypes.h>
  79 #include <string.h>
  80 #include <unistd.h>
  81
  82
  83 /*
  84  * "from" is first in range of changed lines; "to" is last+1
  85  * from=to=line after point of insertion for added lines.
  86  */
  87 struct range {
  88         int from;
  89         int to;
  90 };
  91
  92 struct diff {
  93 #define DIFF_TYPE2 2
  94 #define DIFF_TYPE3 3
  95         int type;
  96 #if DEBUG
  97         char *line;
  98 #endif  /* DEBUG */
  99
 100         /* Ranges as lines */
 101         struct range old;
 102         struct range new;
 103 };
 104
 105 #define EFLAG_NONE      0
 106 #define EFLAG_OVERLAP   1
 107 #define EFLAG_NOOVERLAP 2
 108 #define EFLAG_UNMERGED  3
 109
 110 static size_t szchanges;
 111
 112 static struct diff *d13;
 113 static struct diff *d23;
 114 /*
 115  * "de" is used to gather editing scripts.  These are later spewed out in
 116  * reverse order.  Its first element must be all zero, the "old" and "new"
 117  * components of "de" contain line positions. Array overlap indicates which
 118  * sections in "de" correspond to lines that are different in all three files.
 119  */
 120 static struct diff *de;
 121 static char *overlap;
 122 static int  overlapcnt;
 123 static FILE *fp[3];
 124 static int cline[3];            /* # of the last-read line in each file (0-2) */
 125 /*
 126  * The latest known correspondence between line numbers of the 3 files
 127  * is stored in last[1-3];
 128  */
 129 static int last[4];
 130 static int Aflag, eflag, iflag, mflag, Tflag;
 131 static int oflag;               /* indicates whether to mark overlaps (-E or -X) */
 132 static int strip_cr;
 133 static char *f1mark, *f2mark, *f3mark;
 134 static const char *oldmark = "<<<<<<<";
 135 static const char *orgmark = "|||||||";
 136 static const char *newmark = ">>>>>>>";
 137 static const char *divider = "=======";
 138
 139 static bool duplicate(struct range *, struct range *);
 140 static int edit(struct diff *, bool, int, int);
 141 static char *getchange(FILE *);
 142 static char *get_line(FILE *, size_t *);
 143 static int readin(int fd, struct diff **);
 144 static int skip(int, int, const char *);
 145 static void change(int, struct range *, bool);
 146 static void keep(int, struct range *);
 147 static void merge(int, int);
 148 static void prange(struct range *, bool);
 149 static void repos(int);
 150 static void edscript(int) __dead2;
 151 static void Ascript(int) __dead2;
 152 static void mergescript(int) __dead2;
 153 static void increase(void);
 154 static void usage(void);
 155 static void printrange(FILE *, struct range *);
 156
 157 static const char diff3_version[] = "FreeBSD diff3 20220517";
 158
 159 enum {
 160         DIFFPROG_OPT,
 161         STRIPCR_OPT,
 162         HELP_OPT,
 163         VERSION_OPT
 164 };
 165
 166 #define DIFF_PATH "/usr/bin/diff"
 167
 168 #define OPTIONS "3aAeEiL:mTxX"
 169 static struct option longopts[] = {
 170         { "ed",                 no_argument,            NULL,   'e' },
 171         { "show-overlap",       no_argument,            NULL,   'E' },
 172         { "overlap-only",       no_argument,            NULL,   'x' },
 173         { "initial-tab",        no_argument,            NULL,   'T' },
 174         { "text",               no_argument,            NULL,   'a' },
 175         { "strip-trailing-cr",  no_argument,            NULL,   STRIPCR_OPT },
 176         { "show-all",           no_argument,            NULL,   'A' },
 177         { "easy-only",          no_argument,            NULL,   '3' },
 178         { "merge",              no_argument,            NULL,   'm' },
 179         { "label",              required_argument,      NULL,   'L' },
 180         { "diff-program",       required_argument,      NULL,   DIFFPROG_OPT },
 181         { "help",               no_argument,            NULL,   HELP_OPT},
 182         { "version",            no_argument,            NULL,   VERSION_OPT}
 183 };
 184
 185 static void
 186 usage(void)
 187 {
 188         fprintf(stderr, "usage: diff3 [-3aAeEimTxX] [-L label1] [-L label2] "
 189             "[-L label3] file1 file2 file3\n");
 190 }
 191
 192 static int
 193 readin(int fd, struct diff **dd)
 194 {
 195         int a, b, c, d;
 196         size_t i;
 197         char kind, *p;
 198         FILE *f;
 199
 200         f = fdopen(fd, "r");
 201         if (f == NULL)
 202                 err(2, "fdopen");
 203         for (i = 0; (p = getchange(f)); i++) {
 204 #if DEBUG
 205                 (*dd)[i].line = strdup(p);
 206 #endif  /* DEBUG */
 207
 208                 if (i >= szchanges - 1)
 209                         increase();
 210                 a = b = (int)strtoimax(p, &p, 10);
 211                 if (*p == ',') {
 212                         p++;
 213                         b = (int)strtoimax(p, &p, 10);
 214                 }
 215                 kind = *p++;
 216                 c = d = (int)strtoimax(p, &p, 10);
 217                 if (*p == ',') {
 218                         p++;
 219                         d = (int)strtoimax(p, &p, 10);
 220                 }
 221                 if (kind == 'a')
 222                         a++;
 223                 if (kind == 'd')
 224                         c++;
 225                 b++;
 226                 d++;
 227                 (*dd)[i].old.from = a;
 228                 (*dd)[i].old.to = b;
 229                 (*dd)[i].new.from = c;
 230                 (*dd)[i].new.to = d;
 231         }
 232         if (i) {
 233                 (*dd)[i].old.from = (*dd)[i - 1].old.to;
 234                 (*dd)[i].new.from = (*dd)[i - 1].new.to;
 235         }
 236         fclose(f);
 237         return (i);
 238 }
 239
 240 static int
 241 diffexec(const char *diffprog, char **diffargv, int fd[])
 242 {
 243         int pd;
 244
 245         switch (pdfork(&pd, PD_CLOEXEC)) {
 246         case 0:
 247                 close(fd[0]);
 248                 if (dup2(fd[1], STDOUT_FILENO) == -1)
 249                         err(2, "child could not duplicate descriptor");
 250                 close(fd[1]);
 251                 execvp(diffprog, diffargv);
 252                 err(2, "could not execute diff: %s", diffprog);
 253                 break;
 254         case -1:
 255                 err(2, "could not fork");
 256                 break;
 257         }
 258         close(fd[1]);
 259         return (pd);
 260 }
 261
 262 static char *
 263 getchange(FILE *b)
 264 {
 265         char *line;
 266
 267         while ((line = get_line(b, NULL))) {
 268                 if (isdigit((unsigned char)line[0]))
 269                         return (line);
 270         }
 271         return (NULL);
 272 }
 273
 274
 275 static char *
 276 get_line(FILE *b, size_t *n)
 277 {
 278         ssize_t len;
 279         static char *buf = NULL;
 280         static size_t bufsize = 0;
 281
 282         if ((len = getline(&buf, &bufsize, b)) < 0)
 283                 return (NULL);
 284
 285         if (strip_cr && len >= 2 && strcmp("\r\n", &(buf[len - 2])) == 0) {
 286                 buf[len - 2] = '\n';
 287                 buf[len - 1] = '\0';
 288                 len--;
 289         }
 290
 291         if (n != NULL)
 292                 *n = len;
 293
 294         return (buf);
 295 }
 296
 297 static void
 298 merge(int m1, int m2)
 299 {
 300         struct diff *d1, *d2, *d3;
 301         int j, t1, t2;
 302         bool dup = false;
 303
 304         d1 = d13;
 305         d2 = d23;
 306         j = 0;
 307
 308         while (t1 = d1 < d13 + m1, t2 = d2 < d23 + m2, t1 || t2) {
 309                 /* first file is different from the others */
 310                 if (!t2 || (t1 && d1->new.to < d2->new.from)) {
 311                         /* stuff peculiar to 1st file */
 312                         if (eflag == EFLAG_NONE) {
 313                                 printf("====1\n");
 314                                 change(1, &d1->old, false);
 315                                 keep(2, &d1->new);
 316                                 change(3, &d1->new, false);
 317                         }
 318                         d1++;
 319                         continue;
 320                 }
 321                 /* second file is different from others */
 322                 if (!t1 || (t2 && d2->new.to < d1->new.from)) {
 323                         if (eflag == EFLAG_NONE) {
 324                                 printf("====2\n");
 325                                 keep(1, &d2->new);
 326                                 change(3, &d2->new, false);
 327                                 change(2, &d2->old, false);
 328                         } else if (Aflag || mflag) {
 329                                 // XXX-THJ: What does it mean for the second file to differ?
 330                                 if (eflag == EFLAG_UNMERGED)
 331                                         j = edit(d2, dup, j, DIFF_TYPE2);
 332                         }
 333                         d2++;
 334                         continue;
 335                 }
 336                 /*
 337                  * Merge overlapping changes in first file
 338                  * this happens after extension (see below).
 339                  */
 340                 if (d1 + 1 < d13 + m1 && d1->new.to >= d1[1].new.from) {
 341                         d1[1].old.from = d1->old.from;
 342                         d1[1].new.from = d1->new.from;
 343                         d1++;
 344                         continue;
 345                 }
 346
 347                 /* merge overlapping changes in second */
 348                 if (d2 + 1 < d23 + m2 && d2->new.to >= d2[1].new.from) {
 349                         d2[1].old.from = d2->old.from;
 350                         d2[1].new.from = d2->new.from;
 351                         d2++;
 352                         continue;
 353                 }
 354                 /* stuff peculiar to third file or different in all */
 355                 if (d1->new.from == d2->new.from && d1->new.to == d2->new.to) {
 356                         dup = duplicate(&d1->old, &d2->old);
 357                         /*
 358                          * dup = 0 means all files differ
 359                          * dup = 1 means files 1 and 2 identical
 360                          */
 361                         if (eflag == EFLAG_NONE) {
 362                                 printf("====%s\n", dup ? "3" : "");
 363                                 change(1, &d1->old, dup);
 364                                 change(2, &d2->old, false);
 365                                 d3 = d1->old.to > d1->old.from ? d1 : d2;
 366                                 change(3, &d3->new, false);
 367                         } else {
 368                                 j = edit(d1, dup, j, DIFF_TYPE3);
 369                         }
 370                         dup = false;
 371                         d1++;
 372                         d2++;
 373                         continue;
 374                 }
 375                 /*
 376                  * Overlapping changes from file 1 and 2; extend changes
 377                  * appropriately to make them coincide.
 378                  */
 379                 if (d1->new.from < d2->new.from) {
 380                         d2->old.from -= d2->new.from - d1->new.from;
 381                         d2->new.from = d1->new.from;
 382                 } else if (d2->new.from < d1->new.from) {
 383                         d1->old.from -= d1->new.from - d2->new.from;
 384                         d1->new.from = d2->new.from;
 385                 }
 386                 if (d1->new.to > d2->new.to) {
 387                         d2->old.to += d1->new.to - d2->new.to;
 388                         d2->new.to = d1->new.to;
 389                 } else if (d2->new.to > d1->new.to) {
 390                         d1->old.to += d2->new.to - d1->new.to;
 391                         d1->new.to = d2->new.to;
 392                 }
 393         }
 394
 395         if (mflag)
 396                 mergescript(j);
 397         else if (Aflag)
 398                 Ascript(j);
 399         else if (eflag)
 400                 edscript(j);
 401 }
 402
 403 /*
 404  * The range of lines rold.from thru rold.to in file i is to be changed.
 405  * It is to be printed only if it does not duplicate something to be
 406  * printed later.
 407  */
 408 static void
 409 change(int i, struct range *rold, bool dup)
 410 {
 411
 412         printf("%d:", i);
 413         last[i] = rold->to;
 414         prange(rold, false);
 415         if (dup)
 416                 return;
 417         i--;
 418         skip(i, rold->from, NULL);
 419         skip(i, rold->to, "  ");
 420 }
 421
 422 /*
 423  * Print the range of line numbers, rold.from thru rold.to, as n1,n2 or
 424  * n1.
 425  */
 426 static void
 427 prange(struct range *rold, bool delete)
 428 {
 429
 430         if (rold->to <= rold->from)
 431                 printf("%da\n", rold->from - 1);
 432         else {
 433                 printf("%d", rold->from);
 434                 if (rold->to > rold->from + 1)
 435                         printf(",%d", rold->to - 1);
 436                 if (delete)
 437                         printf("d\n");
 438                 else
 439                         printf("c\n");
 440         }
 441 }
 442
 443 /*
 444  * No difference was reported by diff between file 1 (or 2) and file 3,
 445  * and an artificial dummy difference (trange) must be ginned up to
 446  * correspond to the change reported in the other file.
 447  */
 448 static void
 449 keep(int i, struct range *rnew)
 450 {
 451         int delta;
 452         struct range trange;
 453
 454         delta = last[3] - last[i];
 455         trange.from = rnew->from - delta;
 456         trange.to = rnew->to - delta;
 457         change(i, &trange, true);
 458 }
 459
 460 /*
 461  * skip to just before line number from in file "i".  If "pr" is non-NULL,
 462  * print all skipped stuff with string pr as a prefix.
 463  */
 464 static int
 465 skip(int i, int from, const char *pr)
 466 {
 467         size_t j, n;
 468         char *line;
 469
 470         for (n = 0; cline[i] < from - 1; n += j) {
 471                 if ((line = get_line(fp[i], &j)) == NULL)
 472                         errx(EXIT_FAILURE, "logic error");
 473                 if (pr != NULL)
 474                         printf("%s%s", Tflag == 1 ? "\t" : pr, line);
 475                 cline[i]++;
 476         }
 477         return ((int) n);
 478 }
 479
 480 /*
 481  * Return 1 or 0 according as the old range (in file 1) contains exactly
 482  * the same data as the new range (in file 2).
 483  */
 484 static bool
 485 duplicate(struct range *r1, struct range *r2)
 486 {
 487         int c, d;
 488         int nchar;
 489         int nline;
 490
 491         if (r1->to-r1->from != r2->to-r2->from)
 492                 return (0);
 493         skip(0, r1->from, NULL);
 494         skip(1, r2->from, NULL);
 495         nchar = 0;
 496         for (nline = 0; nline < r1->to - r1->from; nline++) {
 497                 do {
 498                         c = getc(fp[0]);
 499                         d = getc(fp[1]);
 500                         if (c == -1 && d == -1)
 501                                 break;
 502                         if (c == -1 || d == -1)
 503                                 errx(EXIT_FAILURE, "logic error");
 504                         nchar++;
 505                         if (c != d) {
 506                                 repos(nchar);
 507                                 return (0);
 508                         }
 509                 } while (c != '\n');
 510         }
 511         repos(nchar);
 512         return (1);
 513 }
 514
 515 static void
 516 repos(int nchar)
 517 {
 518         int i;
 519
 520         for (i = 0; i < 2; i++)
 521                 (void)fseek(fp[i], (long)-nchar, SEEK_CUR);
 522 }
 523
 524 /*
 525  * collect an editing script for later regurgitation
 526  */
 527 static int
 528 edit(struct diff *diff, bool dup, int j, int difftype)
 529 {
 530         if (!(eflag == EFLAG_UNMERGED ||
 531                 (!dup && eflag == EFLAG_OVERLAP ) ||
 532                 (dup && eflag == EFLAG_NOOVERLAP))) {
 533                 return (j);
 534         }
 535         j++;
 536         overlap[j] = !dup;
 537         if (!dup)
 538                 overlapcnt++;
 539
 540         de[j].type = difftype;
 541 #if DEBUG
 542         de[j].line = strdup(diff->line);
 543 #endif  /* DEBUG */
 544
 545         de[j].old.from = diff->old.from;
 546         de[j].old.to = diff->old.to;
 547         de[j].new.from = diff->new.from;
 548         de[j].new.to = diff->new.to;
 549         return (j);
 550 }
 551
 552 static void
 553 printrange(FILE *p, struct range *r)
 554 {
 555         char *line = NULL;
 556         size_t len = 0;
 557         int i = 1;
 558         ssize_t rlen = 0;
 559
 560         /* We haven't been asked to print anything */
 561         if (r->from == r->to)
 562                 return;
 563
 564         if (r->from > r->to)
 565                 errx(EXIT_FAILURE, "invalid print range");
 566
 567         /*
 568          * XXX-THJ: We read through all of the file for each range printed.
 569          * This duplicates work and will probably impact performance on large
 570          * files with lots of ranges.
 571          */
 572         fseek(p, 0L, SEEK_SET);
 573         while ((rlen = getline(&line, &len, p)) > 0) {
 574                 if (i >= r->from)
 575                         printf("%s", line);
 576                 if (++i > r->to - 1)
 577                         break;
 578         }
 579         free(line);
 580 }
 581
 582 /* regurgitate */
 583 static void
 584 edscript(int n)
 585 {
 586         bool delete;
 587         struct range *new, *old;
 588
 589         for (; n > 0; n--) {
 590                 new = &de[n].new;
 591                 old = &de[n].old;
 592
 593                 delete = (new->from == new->to);
 594                 if (!oflag || !overlap[n]) {
 595                         prange(old, delete);
 596                 } else {
 597                         printf("%da\n", old->to - 1);
 598                         printf("%s\n", divider);
 599                 }
 600                 printrange(fp[2], new);
 601                 if (!oflag || !overlap[n]) {
 602                         if (!delete)
 603                                 printf(".\n");
 604                 } else {
 605                         printf("%s %s\n.\n", newmark, f3mark);
 606                         printf("%da\n%s %s\n.\n", old->from - 1,
 607                                 oldmark, f1mark);
 608                 }
 609         }
 610         if (iflag)
 611                 printf("w\nq\n");
 612
 613         exit(eflag == EFLAG_NONE ? overlapcnt : 0);
 614 }
 615
 616 /*
 617  * Output an edit script to turn mine into yours, when there is a conflict
 618  * between the 3 files bracket the changes. Regurgitate the diffs in reverse
 619  * order to allow the ed script to track down where the lines are as changes
 620  * are made.
 621  */
 622 static void
 623 Ascript(int n)
 624 {
 625         int startmark;
 626         bool deletenew;
 627         bool deleteold;
 628
 629         struct range *new, *old;
 630
 631         for (; n > 0; n--) {
 632                 new = &de[n].new;
 633                 old = &de[n].old;
 634                 deletenew = (new->from == new->to);
 635                 deleteold = (old->from == old->to);
 636
 637                 if (de[n].type == DIFF_TYPE2) {
 638                         if (!oflag || !overlap[n]) {
 639                                 prange(old, deletenew);
 640                                 printrange(fp[2], new);
 641                         } else {
 642                                 startmark = new->to;
 643
 644                                 if (!deletenew)
 645                                         startmark--;
 646
 647                                 printf("%da\n", startmark);
 648                                 printf("%s %s\n", newmark, f3mark);
 649
 650                                 printf(".\n");
 651
 652                                 printf("%da\n", startmark -
 653                                         (new->to - new->from));
 654                                 printf("%s %s\n", oldmark, f2mark);
 655                                 if (!deleteold)
 656                                         printrange(fp[1], old);
 657                                 printf("%s\n.\n", divider);
 658                         }
 659
 660                 } else if (de[n].type == DIFF_TYPE3) {
 661                         startmark = old->to - 1;
 662
 663                         if (!oflag || !overlap[n]) {
 664                                 prange(old, deletenew);
 665                                 printrange(fp[2], new);
 666                         } else {
 667                                 printf("%da\n", startmark);
 668                                 printf("%s %s\n", orgmark, f2mark);
 669
 670                                 if (deleteold) {
 671                                         struct range r;
 672                                         r.from = old->from-1;
 673                                         r.to = new->to;
 674                                         printrange(fp[1], &r);
 675                                 } else
 676                                         printrange(fp[1], old);
 677
 678                                 printf("%s\n", divider);
 679                                 printrange(fp[2], new);
 680                         }
 681
 682                         if (!oflag || !overlap[n]) {
 683                                 if (!deletenew)
 684                                         printf(".\n");
 685                         } else {
 686                                 printf("%s %s\n.\n", newmark, f3mark);
 687
 688                                 /*
 689                                  * Go to the start of the conflict in original
 690                                  * file and append lines
 691                                  */
 692                                 printf("%da\n%s %s\n.\n",
 693                                         startmark - (old->to - old->from),
 694                                         oldmark, f1mark);
 695                         }
 696                 }
 697         }
 698         if (iflag)
 699                 printf("w\nq\n");
 700
 701         exit(overlapcnt > 0);
 702 }
 703
 704 /*
 705  * Output the merged file directly (don't generate an ed script). When
 706  * regurgitating diffs we need to walk forward through the file and print any
 707  * inbetween lines.
 708  */
 709 static void
 710 mergescript(int i)
 711 {
 712         struct range r, *new, *old;
 713         int n;
 714
 715         r.from = 1;
 716         r.to = 1;
 717
 718         for (n = 1; n < i+1; n++) {
 719                 new = &de[n].new;
 720                 old = &de[n].old;
 721
 722                 /* print any lines leading up to here */
 723                 r.to = old->from;
 724                 printrange(fp[0], &r);
 725
 726                 if (de[n].type == DIFF_TYPE2) {
 727                         printf("%s %s\n", oldmark, f2mark);
 728                         printrange(fp[1], old);
 729                         printf("%s\n", divider);
 730                         printrange(fp[2], new);
 731                         printf("%s %s\n", newmark, f3mark);
 732                 } else if (de[n].type == DIFF_TYPE3) {
 733                         if (!oflag || !overlap[n]) {
 734                                 printrange(fp[2], new);
 735                         } else {
 736
 737                                 printf("%s %s\n", oldmark, f1mark);
 738                                 printrange(fp[0], old);
 739
 740                                 printf("%s %s\n", orgmark, f2mark);
 741                                 if (old->from == old->to) {
 742                                         struct range or;
 743                                         or.from = old->from - 1;
 744                                         or.to = new->to;
 745                                         printrange(fp[1], &or);
 746                                 } else
 747                                         printrange(fp[1], old);
 748
 749                                 printf("%s\n", divider);
 750
 751                                 printrange(fp[2], new);
 752                                 printf("%s %s\n", newmark, f3mark);
 753                         }
 754                 }
 755
 756                 if (old->from == old->to)
 757                         r.from = new->to;
 758                 else
 759                         r.from = old->to;
 760         }
 761         /*
 762          * Print from the final range to the end of 'myfile'. Any deletions or
 763          * additions to this file should have been handled by now.
 764          *
 765          * If the ranges are the same we need to rewind a line.
 766          * If the new range is 0 length (from == to), we need to use the old
 767          * range.
 768          */
 769         new = &de[n-1].new;
 770         old = &de[n-1].old;
 771         if ((old->from == new->from) &&
 772                 (old->to == new->to))
 773                 r.from--;
 774         else if (new->from == new->to)
 775                 r.from = old->from;
 776
 777         /*
 778          * If the range is a 3 way merge then we need to skip a line in the
 779          * trailing output.
 780          */
 781         if (de[n-1].type == DIFF_TYPE3)
 782                 r.from++;
 783
 784         r.to = INT_MAX;
 785         printrange(fp[0], &r);
 786         exit(overlapcnt > 0);
 787 }
 788
 789 static void
 790 increase(void)
 791 {
 792         struct diff *p;
 793         char *q;
 794         size_t newsz, incr;
 795
 796         /* are the memset(3) calls needed? */
 797         newsz = szchanges == 0 ? 64 : 2 * szchanges;
 798         incr = newsz - szchanges;
 799
 800         p = reallocarray(d13, newsz, sizeof(struct diff));
 801         if (p == NULL)
 802                 err(1, NULL);
 803         memset(p + szchanges, 0, incr * sizeof(struct diff));
 804         d13 = p;
 805         p = reallocarray(d23, newsz, sizeof(struct diff));
 806         if (p == NULL)
 807                 err(1, NULL);
 808         memset(p + szchanges, 0, incr * sizeof(struct diff));
 809         d23 = p;
 810         p = reallocarray(de, newsz, sizeof(struct diff));
 811         if (p == NULL)
 812                 err(1, NULL);
 813         memset(p + szchanges, 0, incr * sizeof(struct diff));
 814         de = p;
 815         q = reallocarray(overlap, newsz, sizeof(char));
 816         if (q == NULL)
 817                 err(1, NULL);
 818         memset(q + szchanges, 0, incr * sizeof(char));
 819         overlap = q;
 820         szchanges = newsz;
 821 }
 822
 823
 824 int
 825 main(int argc, char **argv)
 826 {
 827         int ch, nblabels, status, m, n, kq, nke, nleft, i;
 828         char *labels[] = { NULL, NULL, NULL };
 829         const char *diffprog = DIFF_PATH;
 830         char *file1, *file2, *file3;
 831         char *diffargv[7];
 832         int diffargc = 0;
 833         int fd13[2], fd23[2];
 834         int pd13, pd23;
 835         cap_rights_t rights_ro;
 836         struct kevent *e;
 837
 838         nblabels = 0;
 839         eflag = EFLAG_NONE;
 840         oflag = 0;
 841         diffargv[diffargc++] = __DECONST(char *, diffprog);
 842         while ((ch = getopt_long(argc, argv, OPTIONS, longopts, NULL)) != -1) {
 843                 switch (ch) {
 844                 case '3':
 845                         eflag = EFLAG_NOOVERLAP;
 846                         break;
 847                 case 'a':
 848                         diffargv[diffargc++] = __DECONST(char *, "-a");
 849                         break;
 850                 case 'A':
 851                         Aflag = 1;
 852                         break;
 853                 case 'e':
 854                         eflag = EFLAG_UNMERGED;
 855                         break;
 856                 case 'E':
 857                         eflag = EFLAG_OVERLAP;
 858                         oflag = 1;
 859                         break;
 860                 case 'i':
 861                         iflag = 1;
 862                         break;
 863                 case 'L':
 864                         oflag = 1;
 865                         if (nblabels >= 3)
 866                                 errx(2, "too many file label options");
 867                         labels[nblabels++] = optarg;
 868                         break;
 869                 case 'm':
 870                         Aflag = 1;
 871                         oflag = 1;
 872                         mflag = 1;
 873                         break;
 874                 case 'T':
 875                         Tflag = 1;
 876                         break;
 877                 case 'x':
 878                         eflag = EFLAG_OVERLAP;
 879                         break;
 880                 case 'X':
 881                         oflag = 1;
 882                         eflag = EFLAG_OVERLAP;
 883                         break;
 884                 case DIFFPROG_OPT:
 885                         diffprog = optarg;
 886                         break;
 887                 case STRIPCR_OPT:
 888                         strip_cr = 1;
 889                         diffargv[diffargc++] = __DECONST(char *, "--strip-trailing-cr");
 890                         break;
 891                 case HELP_OPT:
 892                         usage();
 893                         exit(0);
 894                 case VERSION_OPT:
 895                         printf("%s\n", diff3_version);
 896                         exit(0);
 897                 }
 898         }
 899         argc -= optind;
 900         argv += optind;
 901
 902         if (Aflag) {
 903                 if (eflag == EFLAG_NONE)
 904                         eflag = EFLAG_UNMERGED;
 905                 oflag = 1;
 906         }
 907
 908         if (argc != 3) {
 909                 usage();
 910                 exit(2);
 911         }
 912
 913         if (caph_limit_stdio() == -1)
 914                 err(2, "unable to limit stdio");
 915
 916         cap_rights_init(&rights_ro, CAP_READ, CAP_FSTAT, CAP_SEEK);
 917
 918         kq = kqueue();
 919         if (kq == -1)
 920                 err(2, "kqueue");
 921
 922         e = malloc(2 * sizeof(struct kevent));
 923         if (e == NULL)
 924                 err(2, "malloc");
 925
 926         /* TODO stdio */
 927         file1 = argv[0];
 928         file2 = argv[1];
 929         file3 = argv[2];
 930
 931         if (oflag) {
 932                 asprintf(&f1mark, "%s",
 933                     labels[0] != NULL ? labels[0] : file1);
 934                 if (f1mark == NULL)
 935                         err(2, "asprintf");
 936                 asprintf(&f2mark, "%s",
 937                     labels[1] != NULL ? labels[1] : file2);
 938                 if (f2mark == NULL)
 939                         err(2, "asprintf");
 940                 asprintf(&f3mark, "%s",
 941                     labels[2] != NULL ? labels[2] : file3);
 942                 if (f3mark == NULL)
 943                         err(2, "asprintf");
 944         }
 945         fp[0] = fopen(file1, "r");
 946         if (fp[0] == NULL)
 947                 err(2, "Can't open %s", file1);
 948         if (caph_rights_limit(fileno(fp[0]), &rights_ro) < 0)
 949                 err(2, "unable to limit rights on: %s", file1);
 950
 951         fp[1] = fopen(file2, "r");
 952         if (fp[1] == NULL)
 953                 err(2, "Can't open %s", file2);
 954         if (caph_rights_limit(fileno(fp[1]), &rights_ro) < 0)
 955                 err(2, "unable to limit rights on: %s", file2);
 956
 957         fp[2] = fopen(file3, "r");
 958         if (fp[2] == NULL)
 959                 err(2, "Can't open %s", file3);
 960         if (caph_rights_limit(fileno(fp[2]), &rights_ro) < 0)
 961                 err(2, "unable to limit rights on: %s", file3);
 962
 963         if (pipe(fd13))
 964                 err(2, "pipe");
 965         if (pipe(fd23))
 966                 err(2, "pipe");
 967
 968         diffargv[diffargc] = file1;
 969         diffargv[diffargc + 1] = file3;
 970         diffargv[diffargc + 2] = NULL;
 971
 972         nleft = 0;
 973         pd13 = diffexec(diffprog, diffargv, fd13);
 974         EV_SET(e + nleft , pd13, EVFILT_PROCDESC, EV_ADD, NOTE_EXIT, 0, NULL);
 975         if (kevent(kq, e + nleft, 1, NULL, 0, NULL) == -1)
 976                 err(2, "kevent1");
 977         nleft++;
 978
 979         diffargv[diffargc] = file2;
 980         pd23 = diffexec(diffprog, diffargv, fd23);
 981         EV_SET(e + nleft , pd23, EVFILT_PROCDESC, EV_ADD, NOTE_EXIT, 0, NULL);
 982         if (kevent(kq, e + nleft, 1, NULL, 0, NULL) == -1)
 983                 err(2, "kevent2");
 984         nleft++;
 985
 986         caph_cache_catpages();
 987         if (caph_enter() < 0)
 988                 err(2, "unable to enter capability mode");
 989
 990         /* parse diffs */
 991         increase();
 992         m = readin(fd13[0], &d13);
 993         n = readin(fd23[0], &d23);
 994
 995         /* waitpid cooked over pdforks */
 996         while (nleft > 0) {
 997                 nke = kevent(kq, NULL, 0, e, nleft, NULL);
 998                 if (nke == -1)
 999                         err(2, "kevent");
1000                 for (i = 0; i < nke; i++) {
1001                         status = e[i].data;
1002                         if (WIFEXITED(status) && WEXITSTATUS(status) >= 2)
1003                                 errx(2, "diff exited abnormally");
1004                         else if (WIFSIGNALED(status))
1005                                 errx(2, "diff killed by signal %d",
1006                                     WTERMSIG(status));
1007                 }
1008                 nleft -= nke;
1009         }
1010         merge(m, n);
1011
1012         return (EXIT_SUCCESS);
1013 }