extract.c

   1 /*
   2  * wiggle - apply rejected patches
   3  *
   4  * Copyright (C) 2003 Neil Brown <neilb@cse.unsw.edu.au>
   5  * Copyright (C) 2010-2013 Neil Brown <neilb@suse.de>
   6  *
   7  *
   8  *    This program is free software; you can redistribute it and/or modify
   9  *    it under the terms of the GNU General Public License as published by
  10  *    the Free Software Foundation; either version 2 of the License, or
  11  *    (at your option) any later version.
  12  *
  13  *    This program is distributed in the hope that it will be useful,
  14  *    but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  *    GNU General Public License for more details.
  17  *
  18  *    You should have received a copy of the GNU General Public License
  19  *    along with this program.
  20  *
  21  *    Author: Neil Brown
  22  *    Email: <neilb@suse.de>
  23  */
  24
  25 /*
  26  * split patch or merge files.
  27  */
  28
  29 #include        "wiggle.h"
  30 #include        <stdlib.h>
  31
  32 /* skip 'cp' past the new '\n', or all the way to 'end' */
  33 static void skip_eol(char **cp, char *end)
  34 {
  35         char *c = *cp;
  36         while (c < end && *c != '\n')
  37                 c++;
  38         if (c < end)
  39                 c++;
  40         *cp = c;
  41 }
  42
  43 /* copy one line, or to end, from 'cp' into the stream, extending
  44  * the stream.
  45  */
  46 static void copyline(struct stream *s, char **cp, char *end)
  47 {
  48         char *from = *cp;
  49         char *to = s->body+s->len;
  50
  51         while (from < end && *from != '\n')
  52                 *to++ = *from++;
  53         if (from < end)
  54                 *to++ = *from++;
  55         s->len = to-s->body;
  56         *cp = from;
  57 }
  58
  59 int split_patch(struct stream f, struct stream *f1, struct stream *f2)
  60 {
  61         struct stream r1, r2;
  62         int chunks = 0;
  63         char *cp, *end;
  64         int state = 0;
  65         int acnt = 0, bcnt = 0;
  66         int a, b, c, d;
  67         int lineno = 0;
  68         char before[100], after[100];
  69         char func[100];
  70
  71         f1->body = f2->body = NULL;
  72
  73         r1.body = xmalloc(f.len);
  74         r2.body = xmalloc(f.len);
  75         r1.len = r2.len = 0;
  76         func[0] = 0;
  77
  78         cp = f.body;
  79         end = f.body+f.len;
  80         while (cp < end) {
  81                 /* state:
  82                  *   0   not in a patch
  83                  *   1   first half of context
  84                  *   2   second half of context
  85                  *   3   unified
  86                  */
  87                 lineno++;
  88                 switch (state) {
  89                 case 0:
  90                         if (sscanf(cp, "@@ -%99s +%99s @@%99[^\n]", before, after, func) >= 2) {
  91                                 int ok = 1;
  92                                 if (sscanf(before, "%d,%d", &a, &b) == 2)
  93                                         acnt = b;
  94                                 else if (sscanf(before, "%d", &a) == 1)
  95                                         acnt = 1;
  96                                 else
  97                                         ok = 0;
  98
  99                                 if (sscanf(after, "%d,%d", &c, &d) == 2)
 100                                         bcnt = d;
 101                                 else if (sscanf(after, "%d", &c) == 1)
 102                                         bcnt = 1;
 103                                 else
 104                                         ok = 0;
 105                                 if (ok)
 106                                         state = 3;
 107                                 else
 108                                         state = 0;
 109                         } else if (sscanf(cp, "*** %d,%d ****", &a, &b) == 2) {
 110                                 acnt = b-a+1;
 111                                 state = 1;
 112                         } else if (sscanf(cp, "--- %d,%d ----", &c, &d) == 2) {
 113                                 bcnt = d-c+1;
 114                                 state = 2;
 115                         } else
 116                                 sscanf(cp, "***************%99[^\n]", func);
 117
 118                         skip_eol(&cp, end);
 119                         if (state == 1 || state == 3) {
 120                                 char *f;
 121                                 int slen;
 122                                 /* Reserve enough space for 3 integers separated
 123                                  * by a single space, and prefixed and terminated
 124                                  * with a null character.
 125                                  */
 126                                 char buf[(3*12)+1];
 127                                 buf[0] = 0;
 128                                 chunks++;
 129                                 slen = sprintf(buf+1, "%5d %5d %5d", chunks, a, acnt)+1;
 130                                 memcpy(r1.body+r1.len, buf, slen);
 131                                 r1.len += slen;
 132                                 f = func;
 133                                 while (*f == ' ')
 134                                         f++;
 135                                 if (*f) {
 136                                         r1.body[r1.len++] = ' ';
 137                                         strcpy(r1.body + r1.len, f);
 138                                         r1.len += strlen(f);
 139                                 }
 140                                 r1.body[r1.len++] = '\n';
 141                                 r1.body[r1.len++] = '\0';
 142                         }
 143                         if (state == 2 || state == 3) {
 144                                 int slen;
 145                                 /* Reserve enough space for 3 integers separated
 146                                  * by a single space, prefixed with a null character
 147                                  * and terminated with a new line and null character.
 148                                  */
 149                                 char buf[(3*12)+2];
 150                                 buf[0] = 0;
 151                                 slen = sprintf(buf+1, "%5d %5d %5d\n", chunks, c, bcnt)+2;
 152                                 memcpy(r2.body+r2.len, buf, slen);
 153                                 r2.len += slen;
 154                         }
 155                         if (state)
 156                                 func[0] = 0;
 157                         break;
 158                 case 1:
 159                         if ((*cp == ' ' || *cp == '!' || *cp == '-' || *cp == '+')
 160                             && cp[1] == ' ') {
 161                                 cp += 2;
 162                                 copyline(&r1, &cp, end);
 163                                 acnt--;
 164                                 if (acnt == 0)
 165                                         state = 0;
 166                         } else {
 167                                 fprintf(stderr, "%s: bad context patch at line %d\n",
 168                                         Cmd, lineno);
 169                                 return 0;
 170                         }
 171                         break;
 172                 case 2:
 173                         if ((*cp == ' ' || *cp == '!' || *cp == '-' || *cp == '+')
 174                             && cp[1] == ' ') {
 175                                 cp += 2;
 176                                 copyline(&r2, &cp, end);
 177                                 bcnt--;
 178                                 if (bcnt == 0)
 179                                         state = 0;
 180                         } else {
 181                                 fprintf(stderr, "%s: bad context patch/2 at line %d\n",
 182                                         Cmd, lineno);
 183                                 return 0;
 184                         }
 185                         break;
 186                 case 3:
 187                         if (*cp == ' ') {
 188                                 char *cp2;
 189                                 cp++;
 190                                 cp2 = cp;
 191                                 copyline(&r1, &cp, end);
 192                                 copyline(&r2, &cp2, end);
 193                                 acnt--; bcnt--;
 194                         } else if (*cp == '-') {
 195                                 cp++;
 196                                 copyline(&r1, &cp, end);
 197                                 acnt--;
 198                         } else if (*cp == '+') {
 199                                 cp++;
 200                                 copyline(&r2, &cp, end);
 201                                 bcnt--;
 202                         } else if (*cp == '\n') {
 203                                 /* Empty line - treat like " \n" - a blank line in both */
 204                                 char *cp2 = cp;
 205                                 copyline(&r1, &cp, end);
 206                                 copyline(&r2, &cp2, end);
 207                                 acnt --; bcnt--;
 208                         } else {
 209                                 fprintf(stderr, "%s: bad unified patch at line %d\n",
 210                                         Cmd, lineno);
 211                                 return 0;
 212                         }
 213                         if (acnt <= 0 && bcnt <= 0)
 214                                 state = 0;
 215                         break;
 216                 }
 217         }
 218         if (r1.len > f.len || r2.len > f.len)
 219                 abort();
 220         *f1 = r1;
 221         *f2 = r2;
 222         return chunks;
 223 }
 224
 225 /*
 226  * extract parts of a "diff3 -m" or "wiggle -m" output
 227  */
 228 int split_merge(struct stream f, struct stream *f1, struct stream *f2, struct stream *f3)
 229 {
 230         int state = 0;
 231         char *cp, *end;
 232         struct stream r1, r2, r3;
 233         f1->body = NULL;
 234         f2->body = NULL;
 235
 236         r1.body = xmalloc(f.len);
 237         r2.body = xmalloc(f.len);
 238         r3.body = xmalloc(f.len);
 239         r1.len = r2.len = r3.len = 0;
 240
 241         cp = f.body;
 242         end = f.body+f.len;
 243         while (cp < end) {
 244                 /* state:
 245                  *  0 not in conflict
 246                  *  1 in file 1 of conflict
 247                  *  2 in file 2 of conflict
 248                  *  3 in file 3 of conflict
 249                  *  4 in file 2 but expecting 1/3 next
 250                  *  5 in file 1/3
 251                  */
 252                 int len = end-cp;
 253                 switch (state) {
 254                 case 0:
 255                         if (len >= 8 &&
 256                             strncmp(cp, "<<<<<<<", 7) == 0 &&
 257                             (cp[7] == ' ' || cp[7] == '\n')
 258                                 ) {
 259                                 char *peek;
 260                                 state = 1;
 261                                 skip_eol(&cp, end);
 262                                 /* diff3 will do something a bit strange in
 263                                  * the 1st and 3rd sections are the same.
 264                                  * it reports
 265                                  * <<<<<<<
 266                                  * 2nd
 267                                  * =======
 268                                  * 1st and 3rd
 269                                  * >>>>>>>
 270                                  * Without a ||||||| at all.
 271                                  * so to know if we are in '1' or '2', skip forward
 272                                  * having a peek.
 273                                  */
 274                                 peek = cp;
 275                                 while (peek < end) {
 276                                         if (end-peek >= 8 &&
 277                                             (peek[7] == ' ' || peek[7] == '\n')) {
 278                                                 if (strncmp(peek, "|||||||", 7) == 0 ||
 279                                                     strncmp(peek, ">>>>>>>", 7) == 0)
 280                                                         break;
 281                                                 else if (strncmp(peek, "=======", 7) == 0) {
 282                                                         state = 4;
 283                                                         break;
 284                                                 }
 285                                         }
 286                                         skip_eol(&peek, end);
 287                                 }
 288                         } else {
 289                                 char *cp2 = cp;
 290                                 copyline(&r1, &cp2, end);
 291                                 cp2 = cp;
 292                                 copyline(&r2, &cp2, end);
 293                                 copyline(&r3, &cp, end);
 294                         }
 295                         break;
 296                 case 1:
 297                         if (len >= 8 &&
 298                             strncmp(cp, "|||||||", 7) == 0 &&
 299                             (cp[7] == ' ' || cp[7] == '\n')
 300                                 ) {
 301                                 state = 2;
 302                                 skip_eol(&cp, end);
 303                         } else
 304                                 copyline(&r1, &cp, end);
 305                         break;
 306                 case 2:
 307                         if (len >= 8 &&
 308                             strncmp(cp, "=======", 7) == 0 &&
 309                             (cp[7] == ' ' || cp[7] == '\n')
 310                                 ) {
 311                                 state = 3;
 312                                 skip_eol(&cp, end);
 313                         } else
 314                                 copyline(&r2, &cp, end);
 315                         break;
 316                 case 3:
 317                         if (len >= 8 &&
 318                             strncmp(cp, ">>>>>>>", 7) == 0 &&
 319                             (cp[7] == ' ' || cp[7] == '\n')
 320                                 ) {
 321                                 state = 0;
 322                                 skip_eol(&cp, end);
 323                         } else
 324                                 copyline(&r3, &cp, end);
 325                         break;
 326                 case 4:
 327                         if (len >= 8 &&
 328                             strncmp(cp, "=======", 7) == 0 &&
 329                             (cp[7] == ' ' || cp[7] == '\n')
 330                                 ) {
 331                                 state = 5;
 332                                 skip_eol(&cp, end);
 333                         } else
 334                                 copyline(&r2, &cp, end);
 335                         break;
 336                 case 5:
 337                         if (len >= 8 &&
 338                             strncmp(cp, ">>>>>>>", 7) == 0 &&
 339                             (cp[7] == ' ' || cp[7] == '\n')
 340                                 ) {
 341                                 state = 0;
 342                                 skip_eol(&cp, end);
 343                         } else {
 344                                 char *t = cp;
 345                                 copyline(&r1, &t, end);
 346                                 copyline(&r3, &cp, end);
 347                         }
 348                         break;
 349                 }
 350         }
 351         if (cp > end)
 352                 abort();
 353         *f1 = r1;
 354         *f2 = r2;
 355         *f3 = r3;
 356         return state == 0;
 357 }