gnu/usr.bin/rcs/lib/merger.c

   1 /*      $NetBSD: merger.c,v 1.1.1.2 1996/10/13 21:57:08 veego Exp $     */
   2
   3 /* three-way file merge internals */
   4
   5 /* Copyright 1991, 1992, 1993, 1994, 1995 Paul Eggert
   6    Distributed under license by the Free Software Foundation, Inc.
   7
   8 This file is part of RCS.
   9
  10 RCS is free software; you can redistribute it and/or modify
  11 it under the terms of the GNU General Public License as published by
  12 the Free Software Foundation; either version 2, or (at your option)
  13 any later version.
  14
  15 RCS is distributed in the hope that it will be useful,
  16 but WITHOUT ANY WARRANTY; without even the implied warranty of
  17 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18 GNU General Public License for more details.
  19
  20 You should have received a copy of the GNU General Public License
  21 along with RCS; see the file COPYING.
  22 If not, write to the Free Software Foundation,
  23 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  24
  25 Report problems and direct all questions to:
  26
  27     rcs-bugs@cs.purdue.edu
  28
  29 */
  30
  31 #include "rcsbase.h"
  32
  33 libId(mergerId, "Id: merger.c,v 1.7 1995/06/16 06:19:24 eggert Exp")
  34
  35         static char const *normalize_arg P((char const*,char**));
  36         static char const *
  37 normalize_arg(s, b)
  38         char const *s;
  39         char **b;
  40 /*
  41  * If S looks like an option, prepend ./ to it.  Yield the result.
  42  * Set *B to the address of any storage that was allocated.
  43  */
  44 {
  45         char *t;
  46         if (*s == '-') {
  47                 *b = t = testalloc(strlen(s) + 3);
  48                 VOID sprintf(t, ".%c%s", SLASH, s);
  49                 return t;
  50         } else {
  51                 *b = 0;
  52                 return s;
  53         }
  54 }
  55
  56         int
  57 merge(tostdout, edarg, label, argv)
  58         int tostdout;
  59         char const *edarg;
  60         char const *const label[3];
  61         char const *const argv[3];
  62 /*
  63  * Do `merge [-p] EDARG -L l0 -L l1 -L l2 a0 a1 a2',
  64  * where TOSTDOUT specifies whether -p is present,
  65  * EDARG gives the editing type (e.g. "-A", or null for the default),
  66  * LABEL gives l0, l1 and l2, and ARGV gives a0, a1 and a2.
  67  * Yield DIFF_SUCCESS or DIFF_FAILURE.
  68  */
  69 {
  70         register int i;
  71         FILE *f;
  72         RILE *rt;
  73         char const *a[3], *t;
  74         char *b[3];
  75         int s;
  76 #if !DIFF3_BIN
  77         char const *d[2];
  78 #endif
  79
  80         for (i=3; 0<=--i; )
  81                 a[i] = normalize_arg(argv[i], &b[i]);
  82
  83         if (!edarg)
  84                 edarg = "-E";
  85
  86 #if DIFF3_BIN
  87         t = 0;
  88         if (!tostdout)
  89                 t = maketemp(0);
  90         s = run(
  91                 -1, t,
  92                 DIFF3, edarg, "-am",
  93                 "-L", label[0],
  94                 "-L", label[1],
  95                 "-L", label[2],
  96                 a[0], a[1], a[2], (char*)0
  97         );
  98         switch (s) {
  99                 case DIFF_SUCCESS:
 100                         break;
 101                 case DIFF_FAILURE:
 102                         warn("conflicts during merge");
 103                         break;
 104                 default:
 105                         exiterr();
 106         }
 107         if (t) {
 108                 if (!(f = fopenSafer(argv[0], "w")))
 109                         efaterror(argv[0]);
 110                 if (!(rt = Iopen(t, "r", (struct stat*)0)))
 111                         efaterror(t);
 112                 fastcopy(rt, f);
 113                 Ifclose(rt);
 114                 Ofclose(f);
 115         }
 116 #else
 117         for (i=0; i<2; i++)
 118                 switch (run(
 119                         -1, d[i]=maketemp(i),
 120                         DIFF, a[i], a[2], (char*)0
 121                 )) {
 122                         case DIFF_FAILURE: case DIFF_SUCCESS: break;
 123                         default: faterror("diff failed");
 124                 }
 125         t = maketemp(2);
 126         s = run(
 127                 -1, t,
 128                 DIFF3, edarg, d[0], d[1], a[0], a[1], a[2],
 129                 label[0], label[2], (char*)0
 130         );
 131         if (s != DIFF_SUCCESS) {
 132                 s = DIFF_FAILURE;
 133                 warn("overlaps or other problems during merge");
 134         }
 135         if (!(f = fopenSafer(t, "a+")))
 136                 efaterror(t);
 137         aputs(tostdout ? "1,$p\n" : "w\n",  f);
 138         Orewind(f);
 139         aflush(f);
 140         if (run(fileno(f), (char*)0, ED, "-", a[0], (char*)0))
 141                 exiterr();
 142         Ofclose(f);
 143 #endif
 144
 145         tempunlink();
 146         for (i=3; 0<=--i; )
 147                 if (b[i])
 148                         tfree(b[i]);
 149         return s;
 150 }