xdiff-interface.c

   1 #include "cache.h"
   2 #include "xdiff-interface.h"
   3 #include "xdiff/xtypes.h"
   4 #include "xdiff/xdiffi.h"
   5 #include "xdiff/xemit.h"
   6 #include "xdiff/xmacros.h"
   7
   8 struct xdiff_emit_state {
   9         xdiff_emit_consume_fn consume;
  10         void *consume_callback_data;
  11         struct strbuf remainder;
  12 };
  13
  14 static int parse_num(char **cp_p, int *num_p)
  15 {
  16         char *cp = *cp_p;
  17         int num = 0;
  18         int read_some;
  19
  20         while ('0' <= *cp && *cp <= '9')
  21                 num = num * 10 + *cp++ - '0';
  22         if (!(read_some = cp - *cp_p))
  23                 return -1;
  24         *cp_p = cp;
  25         *num_p = num;
  26         return 0;
  27 }
  28
  29 int parse_hunk_header(char *line, int len,
  30                       int *ob, int *on,
  31                       int *nb, int *nn)
  32 {
  33         char *cp;
  34         cp = line + 4;
  35         if (parse_num(&cp, ob)) {
  36         bad_line:
  37                 return error("malformed diff output: %s", line);
  38         }
  39         if (*cp == ',') {
  40                 cp++;
  41                 if (parse_num(&cp, on))
  42                         goto bad_line;
  43         }
  44         else
  45                 *on = 1;
  46         if (*cp++ != ' ' || *cp++ != '+')
  47                 goto bad_line;
  48         if (parse_num(&cp, nb))
  49                 goto bad_line;
  50         if (*cp == ',') {
  51                 cp++;
  52                 if (parse_num(&cp, nn))
  53                         goto bad_line;
  54         }
  55         else
  56                 *nn = 1;
  57         return -!!memcmp(cp, " @@", 3);
  58 }
  59
  60 static void consume_one(void *priv_, char *s, unsigned long size)
  61 {
  62         struct xdiff_emit_state *priv = priv_;
  63         char *ep;
  64         while (size) {
  65                 unsigned long this_size;
  66                 ep = memchr(s, '\n', size);
  67                 this_size = (ep == NULL) ? size : (ep - s + 1);
  68                 priv->consume(priv->consume_callback_data, s, this_size);
  69                 size -= this_size;
  70                 s += this_size;
  71         }
  72 }
  73
  74 static int xdiff_outf(void *priv_, mmbuffer_t *mb, int nbuf)
  75 {
  76         struct xdiff_emit_state *priv = priv_;
  77         int i;
  78
  79         for (i = 0; i < nbuf; i++) {
  80                 if (mb[i].ptr[mb[i].size-1] != '\n') {
  81                         /* Incomplete line */
  82                         strbuf_add(&priv->remainder, mb[i].ptr, mb[i].size);
  83                         continue;
  84                 }
  85
  86                 /* we have a complete line */
  87                 if (!priv->remainder.len) {
  88                         consume_one(priv, mb[i].ptr, mb[i].size);
  89                         continue;
  90                 }
  91                 strbuf_add(&priv->remainder, mb[i].ptr, mb[i].size);
  92                 consume_one(priv, priv->remainder.buf, priv->remainder.len);
  93                 strbuf_reset(&priv->remainder);
  94         }
  95         if (priv->remainder.len) {
  96                 consume_one(priv, priv->remainder.buf, priv->remainder.len);
  97                 strbuf_reset(&priv->remainder);
  98         }
  99         return 0;
 100 }
 101
 102 /*
 103  * Trim down common substring at the end of the buffers,
 104  * but leave at least ctx lines at the end.
 105  */
 106 static void trim_common_tail(mmfile_t *a, mmfile_t *b, long ctx)
 107 {
 108         const int blk = 1024;
 109         long trimmed = 0, recovered = 0;
 110         char *ap = a->ptr + a->size;
 111         char *bp = b->ptr + b->size;
 112         long smaller = (a->size < b->size) ? a->size : b->size;
 113
 114         if (ctx)
 115                 return;
 116
 117         while (blk + trimmed <= smaller && !memcmp(ap - blk, bp - blk, blk)) {
 118                 trimmed += blk;
 119                 ap -= blk;
 120                 bp -= blk;
 121         }
 122
 123         while (recovered < trimmed)
 124                 if (ap[recovered++] == '\n')
 125                         break;
 126         a->size -= trimmed - recovered;
 127         b->size -= trimmed - recovered;
 128 }
 129
 130 int xdi_diff(mmfile_t *mf1, mmfile_t *mf2, xpparam_t const *xpp, xdemitconf_t const *xecfg, xdemitcb_t *xecb)
 131 {
 132         mmfile_t a = *mf1;
 133         mmfile_t b = *mf2;
 134
 135         trim_common_tail(&a, &b, xecfg->ctxlen);
 136
 137         return xdl_diff(&a, &b, xpp, xecfg, xecb);
 138 }
 139
 140 int xdi_diff_outf(mmfile_t *mf1, mmfile_t *mf2,
 141                   xdiff_emit_consume_fn fn, void *consume_callback_data,
 142                   xpparam_t const *xpp,
 143                   xdemitconf_t const *xecfg, xdemitcb_t *xecb)
 144 {
 145         int ret;
 146         struct xdiff_emit_state state;
 147
 148         memset(&state, 0, sizeof(state));
 149         state.consume = fn;
 150         state.consume_callback_data = consume_callback_data;
 151         xecb->outf = xdiff_outf;
 152         xecb->priv = &state;
 153         strbuf_init(&state.remainder, 0);
 154         ret = xdi_diff(mf1, mf2, xpp, xecfg, xecb);
 155         strbuf_release(&state.remainder);
 156         return ret;
 157 }
 158
 159 struct xdiff_emit_hunk_state {
 160         xdiff_emit_hunk_consume_fn consume;
 161         void *consume_callback_data;
 162 };
 163
 164 static int process_diff(xdfenv_t *xe, xdchange_t *xscr, xdemitcb_t *ecb,
 165                         xdemitconf_t const *xecfg)
 166 {
 167         long s1, s2, same, p_next, t_next;
 168         xdchange_t *xch, *xche;
 169         struct xdiff_emit_hunk_state *state = ecb->priv;
 170         xdiff_emit_hunk_consume_fn fn = state->consume;
 171         void *consume_callback_data = state->consume_callback_data;
 172
 173         for (xch = xscr; xch; xch = xche->next) {
 174                 xche = xdl_get_hunk(xch, xecfg);
 175
 176                 s1 = XDL_MAX(xch->i1 - xecfg->ctxlen, 0);
 177                 s2 = XDL_MAX(xch->i2 - xecfg->ctxlen, 0);
 178                 same = s2 + XDL_MAX(xch->i1 - s1, 0);
 179                 p_next = xche->i1 + xche->chg1;
 180                 t_next = xche->i2 + xche->chg2;
 181
 182                 fn(consume_callback_data, same, p_next, t_next);
 183         }
 184         return 0;
 185 }
 186
 187 int xdi_diff_hunks(mmfile_t *mf1, mmfile_t *mf2,
 188                    xdiff_emit_hunk_consume_fn fn, void *consume_callback_data,
 189                    xpparam_t const *xpp, xdemitconf_t *xecfg)
 190 {
 191         struct xdiff_emit_hunk_state state;
 192         xdemitcb_t ecb;
 193
 194         memset(&state, 0, sizeof(state));
 195         memset(&ecb, 0, sizeof(ecb));
 196         state.consume = fn;
 197         state.consume_callback_data = consume_callback_data;
 198         xecfg->emit_func = (void (*)())process_diff;
 199         ecb.priv = &state;
 200         return xdi_diff(mf1, mf2, xpp, xecfg, &ecb);
 201 }
 202
 203 int read_mmfile(mmfile_t *ptr, const char *filename)
 204 {
 205         struct stat st;
 206         FILE *f;
 207         size_t sz;
 208
 209         if (stat(filename, &st))
 210                 return error("Could not stat %s", filename);
 211         if ((f = fopen(filename, "rb")) == NULL)
 212                 return error("Could not open %s", filename);
 213         sz = xsize_t(st.st_size);
 214         ptr->ptr = xmalloc(sz ? sz : 1);
 215         if (sz && fread(ptr->ptr, sz, 1, f) != 1)
 216                 return error("Could not read %s", filename);
 217         fclose(f);
 218         ptr->size = sz;
 219         return 0;
 220 }
 221
 222 #define FIRST_FEW_BYTES 8000
 223 int buffer_is_binary(const char *ptr, unsigned long size)
 224 {
 225         if (FIRST_FEW_BYTES < size)
 226                 size = FIRST_FEW_BYTES;
 227         return !!memchr(ptr, 0, size);
 228 }
 229
 230 struct ff_regs {
 231         int nr;
 232         struct ff_reg {
 233                 regex_t re;
 234                 int negate;
 235         } *array;
 236 };
 237
 238 static long ff_regexp(const char *line, long len,
 239                 char *buffer, long buffer_size, void *priv)
 240 {
 241         char *line_buffer;
 242         struct ff_regs *regs = priv;
 243         regmatch_t pmatch[2];
 244         int i;
 245         int result = -1;
 246
 247         /* Exclude terminating newline (and cr) from matching */
 248         if (len > 0 && line[len-1] == '\n') {
 249                 if (len > 1 && line[len-2] == '\r')
 250                         len -= 2;
 251                 else
 252                         len--;
 253         }
 254
 255         line_buffer = xstrndup(line, len); /* make NUL terminated */
 256
 257         for (i = 0; i < regs->nr; i++) {
 258                 struct ff_reg *reg = regs->array + i;
 259                 if (!regexec(&reg->re, line_buffer, 2, pmatch, 0)) {
 260                         if (reg->negate)
 261                                 goto fail;
 262                         break;
 263                 }
 264         }
 265         if (regs->nr <= i)
 266                 goto fail;
 267         i = pmatch[1].rm_so >= 0 ? 1 : 0;
 268         line += pmatch[i].rm_so;
 269         result = pmatch[i].rm_eo - pmatch[i].rm_so;
 270         if (result > buffer_size)
 271                 result = buffer_size;
 272         else
 273                 while (result > 0 && (isspace(line[result - 1])))
 274                         result--;
 275         memcpy(buffer, line, result);
 276  fail:
 277         free(line_buffer);
 278         return result;
 279 }
 280
 281 void xdiff_set_find_func(xdemitconf_t *xecfg, const char *value, int cflags)
 282 {
 283         int i;
 284         struct ff_regs *regs;
 285
 286         xecfg->find_func = ff_regexp;
 287         regs = xecfg->find_func_priv = xmalloc(sizeof(struct ff_regs));
 288         for (i = 0, regs->nr = 1; value[i]; i++)
 289                 if (value[i] == '\n')
 290                         regs->nr++;
 291         regs->array = xmalloc(regs->nr * sizeof(struct ff_reg));
 292         for (i = 0; i < regs->nr; i++) {
 293                 struct ff_reg *reg = regs->array + i;
 294                 const char *ep = strchr(value, '\n'), *expression;
 295                 char *buffer = NULL;
 296
 297                 reg->negate = (*value == '!');
 298                 if (reg->negate && i == regs->nr - 1)
 299                         die("Last expression must not be negated: %s", value);
 300                 if (*value == '!')
 301                         value++;
 302                 if (ep)
 303                         expression = buffer = xstrndup(value, ep - value);
 304                 else
 305                         expression = value;
 306                 if (regcomp(&reg->re, expression, cflags))
 307                         die("Invalid regexp to look for hunk header: %s", expression);
 308                 free(buffer);
 309                 value = ep + 1;
 310         }
 311 }
 312
 313 int git_xmerge_style = -1;
 314
 315 int git_xmerge_config(const char *var, const char *value, void *cb)
 316 {
 317         if (!strcasecmp(var, "merge.conflictstyle")) {
 318                 if (!value)
 319                         die("'%s' is not a boolean", var);
 320                 if (!strcmp(value, "diff3"))
 321                         git_xmerge_style = XDL_MERGE_DIFF3;
 322                 else if (!strcmp(value, "merge"))
 323                         git_xmerge_style = 0;
 324                 else
 325                         die("unknown style '%s' given for '%s'",
 326                             value, var);
 327                 return 0;
 328         }
 329         return git_default_config(var, value, cb);
 330 }