xdiff-interface.c

   1 #include "cache.h"
   2 #include "config.h"
   3 #include "xdiff-interface.h"
   4 #include "xdiff/xtypes.h"
   5 #include "xdiff/xdiffi.h"
   6 #include "xdiff/xemit.h"
   7 #include "xdiff/xmacros.h"
   8 #include "xdiff/xutils.h"
   9
  10 struct xdiff_emit_state {
  11         xdiff_emit_consume_fn consume;
  12         void *consume_callback_data;
  13         struct strbuf remainder;
  14 };
  15
  16 static int parse_num(char **cp_p, int *num_p)
  17 {
  18         char *cp = *cp_p;
  19         int num = 0;
  20
  21         while ('0' <= *cp && *cp <= '9')
  22                 num = num * 10 + *cp++ - '0';
  23         if (!(cp - *cp_p))
  24                 return -1;
  25         *cp_p = cp;
  26         *num_p = num;
  27         return 0;
  28 }
  29
  30 int parse_hunk_header(char *line, int len,
  31                       int *ob, int *on,
  32                       int *nb, int *nn)
  33 {
  34         char *cp;
  35         cp = line + 4;
  36         if (parse_num(&cp, ob)) {
  37         bad_line:
  38                 return error("malformed diff output: %s", line);
  39         }
  40         if (*cp == ',') {
  41                 cp++;
  42                 if (parse_num(&cp, on))
  43                         goto bad_line;
  44         }
  45         else
  46                 *on = 1;
  47         if (*cp++ != ' ' || *cp++ != '+')
  48                 goto bad_line;
  49         if (parse_num(&cp, nb))
  50                 goto bad_line;
  51         if (*cp == ',') {
  52                 cp++;
  53                 if (parse_num(&cp, nn))
  54                         goto bad_line;
  55         }
  56         else
  57                 *nn = 1;
  58         return -!!memcmp(cp, " @@", 3);
  59 }
  60
  61 static void consume_one(void *priv_, char *s, unsigned long size)
  62 {
  63         struct xdiff_emit_state *priv = priv_;
  64         char *ep;
  65         while (size) {
  66                 unsigned long this_size;
  67                 ep = memchr(s, '\n', size);
  68                 this_size = (ep == NULL) ? size : (ep - s + 1);
  69                 priv->consume(priv->consume_callback_data, s, this_size);
  70                 size -= this_size;
  71                 s += this_size;
  72         }
  73 }
  74
  75 static int xdiff_outf(void *priv_, mmbuffer_t *mb, int nbuf)
  76 {
  77         struct xdiff_emit_state *priv = priv_;
  78         int i;
  79
  80         for (i = 0; i < nbuf; i++) {
  81                 if (mb[i].ptr[mb[i].size-1] != '\n') {
  82                         /* Incomplete line */
  83                         strbuf_add(&priv->remainder, mb[i].ptr, mb[i].size);
  84                         continue;
  85                 }
  86
  87                 /* we have a complete line */
  88                 if (!priv->remainder.len) {
  89                         consume_one(priv, mb[i].ptr, mb[i].size);
  90                         continue;
  91                 }
  92                 strbuf_add(&priv->remainder, mb[i].ptr, mb[i].size);
  93                 consume_one(priv, priv->remainder.buf, priv->remainder.len);
  94                 strbuf_reset(&priv->remainder);
  95         }
  96         if (priv->remainder.len) {
  97                 consume_one(priv, priv->remainder.buf, priv->remainder.len);
  98                 strbuf_reset(&priv->remainder);
  99         }
 100         return 0;
 101 }
 102
 103 /*
 104  * Trim down common substring at the end of the buffers,
 105  * but end on a complete line.
 106  */
 107 static void trim_common_tail(mmfile_t *a, mmfile_t *b)
 108 {
 109         const int blk = 1024;
 110         long trimmed = 0, recovered = 0;
 111         char *ap = a->ptr + a->size;
 112         char *bp = b->ptr + b->size;
 113         long smaller = (a->size < b->size) ? a->size : b->size;
 114
 115         while (blk + trimmed <= smaller && !memcmp(ap - blk, bp - blk, blk)) {
 116                 trimmed += blk;
 117                 ap -= blk;
 118                 bp -= blk;
 119         }
 120
 121         while (recovered < trimmed)
 122                 if (ap[recovered++] == '\n')
 123                         break;
 124         a->size -= trimmed - recovered;
 125         b->size -= trimmed - recovered;
 126 }
 127
 128 int xdi_diff(mmfile_t *mf1, mmfile_t *mf2, xpparam_t const *xpp, xdemitconf_t const *xecfg, xdemitcb_t *xecb)
 129 {
 130         mmfile_t a = *mf1;
 131         mmfile_t b = *mf2;
 132
 133         if (mf1->size > MAX_XDIFF_SIZE || mf2->size > MAX_XDIFF_SIZE)
 134                 return -1;
 135
 136         if (!xecfg->ctxlen && !(xecfg->flags & XDL_EMIT_FUNCCONTEXT))
 137                 trim_common_tail(&a, &b);
 138
 139         return xdl_diff(&a, &b, xpp, xecfg, xecb);
 140 }
 141
 142 int xdi_diff_outf(mmfile_t *mf1, mmfile_t *mf2,
 143                   xdiff_emit_consume_fn fn, void *consume_callback_data,
 144                   xpparam_t const *xpp, xdemitconf_t const *xecfg)
 145 {
 146         int ret;
 147         struct xdiff_emit_state state;
 148         xdemitcb_t ecb;
 149
 150         memset(&state, 0, sizeof(state));
 151         state.consume = fn;
 152         state.consume_callback_data = consume_callback_data;
 153         memset(&ecb, 0, sizeof(ecb));
 154         ecb.outf = xdiff_outf;
 155         ecb.priv = &state;
 156         strbuf_init(&state.remainder, 0);
 157         ret = xdi_diff(mf1, mf2, xpp, xecfg, &ecb);
 158         strbuf_release(&state.remainder);
 159         return ret;
 160 }
 161
 162 int read_mmfile(mmfile_t *ptr, const char *filename)
 163 {
 164         struct stat st;
 165         FILE *f;
 166         size_t sz;
 167
 168         if (stat(filename, &st))
 169                 return error_errno("Could not stat %s", filename);
 170         if ((f = fopen(filename, "rb")) == NULL)
 171                 return error_errno("Could not open %s", filename);
 172         sz = xsize_t(st.st_size);
 173         ptr->ptr = xmalloc(sz ? sz : 1);
 174         if (sz && fread(ptr->ptr, sz, 1, f) != 1) {
 175                 fclose(f);
 176                 return error("Could not read %s", filename);
 177         }
 178         fclose(f);
 179         ptr->size = sz;
 180         return 0;
 181 }
 182
 183 void read_mmblob(mmfile_t *ptr, const struct object_id *oid)
 184 {
 185         unsigned long size;
 186         enum object_type type;
 187
 188         if (!oidcmp(oid, &null_oid)) {
 189                 ptr->ptr = xstrdup("");
 190                 ptr->size = 0;
 191                 return;
 192         }
 193
 194         ptr->ptr = read_sha1_file(oid->hash, &type, &size);
 195         if (!ptr->ptr || type != OBJ_BLOB)
 196                 die("unable to read blob object %s", oid_to_hex(oid));
 197         ptr->size = size;
 198 }
 199
 200 #define FIRST_FEW_BYTES 8000
 201 int buffer_is_binary(const char *ptr, unsigned long size)
 202 {
 203         if (FIRST_FEW_BYTES < size)
 204                 size = FIRST_FEW_BYTES;
 205         return !!memchr(ptr, 0, size);
 206 }
 207
 208 struct ff_regs {
 209         int nr;
 210         struct ff_reg {
 211                 regex_t re;
 212                 int negate;
 213         } *array;
 214 };
 215
 216 static long ff_regexp(const char *line, long len,
 217                 char *buffer, long buffer_size, void *priv)
 218 {
 219         struct ff_regs *regs = priv;
 220         regmatch_t pmatch[2];
 221         int i;
 222         int result;
 223
 224         /* Exclude terminating newline (and cr) from matching */
 225         if (len > 0 && line[len-1] == '\n') {
 226                 if (len > 1 && line[len-2] == '\r')
 227                         len -= 2;
 228                 else
 229                         len--;
 230         }
 231
 232         for (i = 0; i < regs->nr; i++) {
 233                 struct ff_reg *reg = regs->array + i;
 234                 if (!regexec_buf(&reg->re, line, len, 2, pmatch, 0)) {
 235                         if (reg->negate)
 236                                 return -1;
 237                         break;
 238                 }
 239         }
 240         if (regs->nr <= i)
 241                 return -1;
 242         i = pmatch[1].rm_so >= 0 ? 1 : 0;
 243         line += pmatch[i].rm_so;
 244         result = pmatch[i].rm_eo - pmatch[i].rm_so;
 245         if (result > buffer_size)
 246                 result = buffer_size;
 247         while (result > 0 && (isspace(line[result - 1])))
 248                 result--;
 249         memcpy(buffer, line, result);
 250         return result;
 251 }
 252
 253 void xdiff_set_find_func(xdemitconf_t *xecfg, const char *value, int cflags)
 254 {
 255         int i;
 256         struct ff_regs *regs;
 257
 258         xecfg->find_func = ff_regexp;
 259         regs = xecfg->find_func_priv = xmalloc(sizeof(struct ff_regs));
 260         for (i = 0, regs->nr = 1; value[i]; i++)
 261                 if (value[i] == '\n')
 262                         regs->nr++;
 263         ALLOC_ARRAY(regs->array, regs->nr);
 264         for (i = 0; i < regs->nr; i++) {
 265                 struct ff_reg *reg = regs->array + i;
 266                 const char *ep = strchr(value, '\n'), *expression;
 267                 char *buffer = NULL;
 268
 269                 reg->negate = (*value == '!');
 270                 if (reg->negate && i == regs->nr - 1)
 271                         die("Last expression must not be negated: %s", value);
 272                 if (*value == '!')
 273                         value++;
 274                 if (ep)
 275                         expression = buffer = xstrndup(value, ep - value);
 276                 else
 277                         expression = value;
 278                 if (regcomp(&reg->re, expression, cflags))
 279                         die("Invalid regexp to look for hunk header: %s", expression);
 280                 free(buffer);
 281                 value = ep + 1;
 282         }
 283 }
 284
 285 void xdiff_clear_find_func(xdemitconf_t *xecfg)
 286 {
 287         if (xecfg->find_func) {
 288                 int i;
 289                 struct ff_regs *regs = xecfg->find_func_priv;
 290
 291                 for (i = 0; i < regs->nr; i++)
 292                         regfree(&regs->array[i].re);
 293                 free(regs->array);
 294                 free(regs);
 295                 xecfg->find_func = NULL;
 296                 xecfg->find_func_priv = NULL;
 297         }
 298 }
 299
 300 unsigned long xdiff_hash_string(const char *s, size_t len, long flags)
 301 {
 302         return xdl_hash_record(&s, s + len, flags);
 303 }
 304
 305 int xdiff_compare_lines(const char *l1, long s1,
 306                         const char *l2, long s2, long flags)
 307 {
 308         return xdl_recmatch(l1, s1, l2, s2, flags);
 309 }
 310
 311 int git_xmerge_style = -1;
 312
 313 int git_xmerge_config(const char *var, const char *value, void *cb)
 314 {
 315         if (!strcmp(var, "merge.conflictstyle")) {
 316                 if (!value)
 317                         die("'%s' is not a boolean", var);
 318                 if (!strcmp(value, "diff3"))
 319                         git_xmerge_style = XDL_MERGE_DIFF3;
 320                 else if (!strcmp(value, "merge"))
 321                         git_xmerge_style = 0;
 322                 else
 323                         die("unknown style '%s' given for '%s'",
 324                             value, var);
 325                 return 0;
 326         }
 327         return git_default_config(var, value, cb);
 328 }