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  * Copyright (C) 2014-2020 Neil Brown <neil@brown.name>
   7  *
   8  *
   9  *    This program is free software; you can redistribute it and/or modify
  10  *    it under the terms of the GNU General Public License as published by
  11  *    the Free Software Foundation; either version 2 of the License, or
  12  *    (at your option) any later version.
  13  *
  14  *    This program is distributed in the hope that it will be useful,
  15  *    but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17  *    GNU General Public License for more details.
  18  *
  19  *    You should have received a copy of the GNU General Public License
  20  *    along with this program.
  21  *
  22  *    Author: Neil Brown
  23  *    Email: <neil@brown.name>
  24  */
  25
  26 /*
  27  * split patch or merge files.
  28  */
  29
  30 #include        "wiggle.h"
  31 #include        <stdlib.h>
  32
  33 /* skip 'cp' past the new '\n', or all the way to 'end' */
  34 static void skip_eol(char **cp, char *end)
  35 {
  36         char *c = *cp;
  37         while (c < end && *c != '\n')
  38                 c++;
  39         if (c < end)
  40                 c++;
  41         *cp = c;
  42 }
  43
  44 /* copy one line, or to end, from 'cp' into the stream, extending
  45  * the stream.
  46  */
  47 static void copyline(struct stream *s, char **cp, char *end)
  48 {
  49         char *from = *cp;
  50         char *to = s->body+s->len;
  51
  52         while (from < end && *from != '\n')
  53                 *to++ = *from++;
  54         if (from < end)
  55                 *to++ = *from++;
  56         s->len = to-s->body;
  57         *cp = from;
  58 }
  59
  60 int wiggle_split_patch(struct stream f, struct stream *f1, struct stream *f2)
  61 {
  62         struct stream r1, r2;
  63         int chunks = 0;
  64         char *cp, *end;
  65         int state = 0;
  66         int acnt = 0, bcnt = 0;
  67         int a, b, c, d;
  68         int lineno = 0;
  69         char before[100], after[100];
  70         char func[100];
  71
  72         f1->body = f2->body = NULL;
  73
  74         r1.body = wiggle_xmalloc(f.len);
  75         r2.body = wiggle_xmalloc(f.len);
  76         r1.len = r2.len = 0;
  77         func[0] = 0;
  78
  79         cp = f.body;
  80         end = f.body+f.len;
  81         while (cp < end) {
  82                 /* state:
  83                  *   0   not in a patch
  84                  *   1   first half of context
  85                  *   2   second half of context
  86                  *   3   unified
  87                  */
  88                 lineno++;
  89                 switch (state) {
  90                 case 0:
  91                         if (sscanf(cp, "@@ -%99s +%99s @@%99[^\n]", before, after, func) >= 2) {
  92                                 int ok = 1;
  93                                 if (sscanf(before, "%d,%d", &a, &b) == 2)
  94                                         acnt = b;
  95                                 else if (sscanf(before, "%d", &a) == 1)
  96                                         acnt = 1;
  97                                 else
  98                                         ok = 0;
  99
 100                                 if (sscanf(after, "%d,%d", &c, &d) == 2)
 101                                         bcnt = d;
 102                                 else if (sscanf(after, "%d", &c) == 1)
 103                                         bcnt = 1;
 104                                 else
 105                                         ok = 0;
 106                                 if (ok)
 107                                         state = 3;
 108                                 else
 109                                         state = 0;
 110                         } else if (sscanf(cp, "*** %d,%d ****", &a, &b) == 2) {
 111                                 acnt = b-a+1;
 112                                 state = 1;
 113                         } else if (sscanf(cp, "--- %d,%d ----", &c, &d) == 2) {
 114                                 bcnt = d-c+1;
 115                                 state = 2;
 116                         } else
 117                                 sscanf(cp, "***************%99[^\n]", func);
 118
 119                         skip_eol(&cp, end);
 120                         if (state == 1 || state == 3) {
 121                                 char *f;
 122                                 int slen;
 123                                 /* Reserve enough space for 3 integers separated
 124                                  * by a single space, and prefixed and terminated
 125                                  * with a null character.
 126                                  */
 127                                 char buf[(3*12)+1];
 128                                 buf[0] = 0;
 129                                 chunks++;
 130                                 slen = sprintf(buf+1, "%5d %5d %5d", chunks, a, acnt)+1;
 131                                 memcpy(r1.body+r1.len, buf, slen);
 132                                 r1.len += slen;
 133                                 f = func;
 134                                 while (*f == ' ')
 135                                         f++;
 136                                 if (*f) {
 137                                         r1.body[r1.len++] = ' ';
 138                                         strcpy(r1.body + r1.len, f);
 139                                         r1.len += strlen(f);
 140                                 }
 141                                 r1.body[r1.len++] = '\n';
 142                                 r1.body[r1.len++] = '\0';
 143                         }
 144                         if (state == 2 || state == 3) {
 145                                 int slen;
 146                                 /* Reserve enough space for 3 integers separated
 147                                  * by a single space, prefixed with a null character
 148                                  * and terminated with a new line and null character.
 149                                  */
 150                                 char buf[(3*12)+2];
 151                                 buf[0] = 0;
 152                                 slen = sprintf(buf+1, "%5d %5d %5d\n", chunks, c, bcnt)+2;
 153                                 memcpy(r2.body+r2.len, buf, slen);
 154                                 r2.len += slen;
 155                         }
 156                         if (state)
 157                                 func[0] = 0;
 158                         break;
 159                 case 1:
 160                         if ((*cp == ' ' || *cp == '!' || *cp == '-' || *cp == '+')
 161                             && cp[1] == ' ') {
 162                                 cp += 2;
 163                                 copyline(&r1, &cp, end);
 164                                 acnt--;
 165                                 if (acnt == 0)
 166                                         state = 0;
 167                         } else {
 168                                 fprintf(stderr, "%s: bad context patch at line %d\n",
 169                                         wiggle_Cmd, lineno);
 170                                 return 0;
 171                         }
 172                         break;
 173                 case 2:
 174                         if ((*cp == ' ' || *cp == '!' || *cp == '-' || *cp == '+')
 175                             && cp[1] == ' ') {
 176                                 cp += 2;
 177                                 copyline(&r2, &cp, end);
 178                                 bcnt--;
 179                                 if (bcnt == 0)
 180                                         state = 0;
 181                         } else {
 182                                 fprintf(stderr, "%s: bad context patch/2 at line %d\n",
 183                                         wiggle_Cmd, lineno);
 184                                 return 0;
 185                         }
 186                         break;
 187                 case 3:
 188                         if (*cp == ' ') {
 189                                 char *cp2;
 190                                 cp++;
 191                                 cp2 = cp;
 192                                 copyline(&r1, &cp, end);
 193                                 copyline(&r2, &cp2, end);
 194                                 acnt--; bcnt--;
 195                         } else if (*cp == '-') {
 196                                 cp++;
 197                                 copyline(&r1, &cp, end);
 198                                 acnt--;
 199                         } else if (*cp == '+') {
 200                                 cp++;
 201                                 copyline(&r2, &cp, end);
 202                                 bcnt--;
 203                         } else if (*cp == '\n') {
 204                                 /* Empty line - treat like " \n" - a blank line in both */
 205                                 char *cp2 = cp;
 206                                 copyline(&r1, &cp, end);
 207                                 copyline(&r2, &cp2, end);
 208                                 acnt --; bcnt--;
 209                         } else {
 210                                 fprintf(stderr, "%s: bad unified patch at line %d\n",
 211                                         wiggle_Cmd, lineno);
 212                                 return 0;
 213                         }
 214                         if (acnt <= 0 && bcnt <= 0)
 215                                 state = 0;
 216                         break;
 217                 }
 218         }
 219         if (r1.len > f.len || r2.len > f.len)
 220                 abort();
 221         *f1 = r1;
 222         *f2 = r2;
 223         return chunks;
 224 }
 225
 226 /*
 227  * extract parts of a "diff3 -m" or "wiggle -m" output
 228  */
 229 int wiggle_split_merge(struct stream f, struct stream *f1, struct stream *f2,
 230                        struct stream *f3)
 231 {
 232         int state = 0;
 233         char *cp, *end;
 234         struct stream r1, r2, r3;
 235         f1->body = NULL;
 236         f2->body = NULL;
 237
 238         r1.body = wiggle_xmalloc(f.len);
 239         r2.body = wiggle_xmalloc(f.len);
 240         r3.body = wiggle_xmalloc(f.len);
 241         r1.len = r2.len = r3.len = 0;
 242
 243         cp = f.body;
 244         end = f.body+f.len;
 245         while (cp < end) {
 246                 /* state:
 247                  *  0 not in conflict
 248                  *  1 in file 1 of conflict
 249                  *  2 in file 2 of conflict
 250                  *  3 in file 3 of conflict
 251                  *  4 in file 2 but expecting 1/3 next
 252                  *  5 in file 1/3
 253                  */
 254                 int len = end-cp;
 255                 switch (state) {
 256                 case 0:
 257                         if (len >= 8 &&
 258                             strncmp(cp, "<<<<<<<", 7) == 0 &&
 259                             (cp[7] == ' ' || cp[7] == '\n')
 260                                 ) {
 261                                 char *peek;
 262                                 state = 1;
 263                                 skip_eol(&cp, end);
 264                                 /* diff3 will do something a bit strange in
 265                                  * the 1st and 3rd sections are the same.
 266                                  * it reports
 267                                  * <<<<<<<
 268                                  * 2nd
 269                                  * =======
 270                                  * 1st and 3rd
 271                                  * >>>>>>>
 272                                  * Without a ||||||| at all.
 273                                  * so to know if we are in '1' or '2', skip forward
 274                                  * having a peek.
 275                                  */
 276                                 peek = cp;
 277                                 while (peek < end) {
 278                                         if (end-peek >= 8 &&
 279                                             (peek[7] == ' ' || peek[7] == '\n')) {
 280                                                 if (strncmp(peek, "|||||||", 7) == 0 ||
 281                                                     strncmp(peek, ">>>>>>>", 7) == 0)
 282                                                         break;
 283                                                 else if (strncmp(peek, "=======", 7) == 0) {
 284                                                         state = 4;
 285                                                         break;
 286                                                 }
 287                                         }
 288                                         skip_eol(&peek, end);
 289                                 }
 290                         } else {
 291                                 char *cp2 = cp;
 292                                 copyline(&r1, &cp2, end);
 293                                 cp2 = cp;
 294                                 copyline(&r2, &cp2, end);
 295                                 copyline(&r3, &cp, end);
 296                         }
 297                         break;
 298                 case 1:
 299                         if (len >= 8 &&
 300                             strncmp(cp, "|||||||", 7) == 0 &&
 301                             (cp[7] == ' ' || cp[7] == '\n')
 302                                 ) {
 303                                 state = 2;
 304                                 skip_eol(&cp, end);
 305                         } else
 306                                 copyline(&r1, &cp, end);
 307                         break;
 308                 case 2:
 309                         if (len >= 8 &&
 310                             strncmp(cp, "=======", 7) == 0 &&
 311                             (cp[7] == ' ' || cp[7] == '\n')
 312                                 ) {
 313                                 state = 3;
 314                                 skip_eol(&cp, end);
 315                         } else
 316                                 copyline(&r2, &cp, end);
 317                         break;
 318                 case 3:
 319                         if (len >= 8 &&
 320                             strncmp(cp, ">>>>>>>", 7) == 0 &&
 321                             (cp[7] == ' ' || cp[7] == '\n')
 322                                 ) {
 323                                 state = 0;
 324                                 skip_eol(&cp, end);
 325                         } else
 326                                 copyline(&r3, &cp, end);
 327                         break;
 328                 case 4:
 329                         if (len >= 8 &&
 330                             strncmp(cp, "=======", 7) == 0 &&
 331                             (cp[7] == ' ' || cp[7] == '\n')
 332                                 ) {
 333                                 state = 5;
 334                                 skip_eol(&cp, end);
 335                         } else
 336                                 copyline(&r2, &cp, end);
 337                         break;
 338                 case 5:
 339                         if (len >= 8 &&
 340                             strncmp(cp, ">>>>>>>", 7) == 0 &&
 341                             (cp[7] == ' ' || cp[7] == '\n')
 342                                 ) {
 343                                 state = 0;
 344                                 skip_eol(&cp, end);
 345                         } else {
 346                                 char *t = cp;
 347                                 copyline(&r1, &t, end);
 348                                 copyline(&r3, &cp, end);
 349                         }
 350                         break;
 351                 }
 352         }
 353         if (cp > end)
 354                 abort();
 355         *f1 = r1;
 356         *f2 = r2;
 357         *f3 = r3;
 358         return state == 0;
 359 }