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
   9 struct xdiff_emit_state {
  10         xdiff_emit_consume_fn consume;
  11         void *consume_callback_data;
  12         struct strbuf remainder;
  13 };
  14
  15 static int parse_num(char **cp_p, int *num_p)
  16 {
  17         char *cp = *cp_p;
  18         int num = 0;
  19
  20         while ('0' <= *cp && *cp <= '9')
  21                 num = num * 10 + *cp++ - '0';
  22         if (!(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 end on a complete line.
 105  */
 106 static void trim_common_tail(mmfile_t *a, mmfile_t *b)
 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         while (blk + trimmed <= smaller && !memcmp(ap - blk, bp - blk, blk)) {
 115                 trimmed += blk;
 116                 ap -= blk;
 117                 bp -= blk;
 118         }
 119
 120         while (recovered < trimmed)
 121                 if (ap[recovered++] == '\n')
 122                         break;
 123         a->size -= trimmed - recovered;
 124         b->size -= trimmed - recovered;
 125 }
 126
 127 int xdi_diff(mmfile_t *mf1, mmfile_t *mf2, xpparam_t const *xpp, xdemitconf_t const *xecfg, xdemitcb_t *xecb)
 128 {
 129         mmfile_t a = *mf1;
 130         mmfile_t b = *mf2;
 131
 132         if (mf1->size > MAX_XDIFF_SIZE || mf2->size > MAX_XDIFF_SIZE)
 133                 return -1;
 134
 135         if (!xecfg->ctxlen && !(xecfg->flags & XDL_EMIT_FUNCCONTEXT))
 136                 trim_common_tail(&a, &b);
 137
 138         return xdl_diff(&a, &b, xpp, xecfg, xecb);
 139 }
 140
 141 int xdi_diff_outf(mmfile_t *mf1, mmfile_t *mf2,
 142                   xdiff_emit_consume_fn fn, void *consume_callback_data,
 143                   xpparam_t const *xpp, xdemitconf_t const *xecfg)
 144 {
 145         int ret;
 146         struct xdiff_emit_state state;
 147         xdemitcb_t ecb;
 148
 149         memset(&state, 0, sizeof(state));
 150         state.consume = fn;
 151         state.consume_callback_data = consume_callback_data;
 152         memset(&ecb, 0, sizeof(ecb));
 153         ecb.outf = xdiff_outf;
 154         ecb.priv = &state;
 155         strbuf_init(&state.remainder, 0);
 156         ret = xdi_diff(mf1, mf2, xpp, xecfg, &ecb);
 157         strbuf_release(&state.remainder);
 158         return ret;
 159 }
 160
 161 int read_mmfile(mmfile_t *ptr, const char *filename)
 162 {
 163         struct stat st;
 164         FILE *f;
 165         size_t sz;
 166
 167         if (stat(filename, &st))
 168                 return error_errno("Could not stat %s", filename);
 169         if ((f = fopen(filename, "rb")) == NULL)
 170                 return error_errno("Could not open %s", filename);
 171         sz = xsize_t(st.st_size);
 172         ptr->ptr = xmalloc(sz ? sz : 1);
 173         if (sz && fread(ptr->ptr, sz, 1, f) != 1) {
 174                 fclose(f);
 175                 return error("Could not read %s", filename);
 176         }
 177         fclose(f);
 178         ptr->size = sz;
 179         return 0;
 180 }
 181
 182 void read_mmblob(mmfile_t *ptr, const struct object_id *oid)
 183 {
 184         unsigned long size;
 185         enum object_type type;
 186
 187         if (!oidcmp(oid, &null_oid)) {
 188                 ptr->ptr = xstrdup("");
 189                 ptr->size = 0;
 190                 return;
 191         }
 192
 193         ptr->ptr = read_sha1_file(oid->hash, &type, &size);
 194         if (!ptr->ptr || type != OBJ_BLOB)
 195                 die("unable to read blob object %s", oid_to_hex(oid));
 196         ptr->size = size;
 197 }
 198
 199 #define FIRST_FEW_BYTES 8000
 200 int buffer_is_binary(const char *ptr, unsigned long size)
 201 {
 202         if (FIRST_FEW_BYTES < size)
 203                 size = FIRST_FEW_BYTES;
 204         return !!memchr(ptr, 0, size);
 205 }
 206
 207 struct ff_regs {
 208         int nr;
 209         struct ff_reg {
 210                 regex_t re;
 211                 int negate;
 212         } *array;
 213 };
 214
 215 static long ff_regexp(const char *line, long len,
 216                 char *buffer, long buffer_size, void *priv)
 217 {
 218         struct ff_regs *regs = priv;
 219         regmatch_t pmatch[2];
 220         int i;
 221         int result;
 222
 223         /* Exclude terminating newline (and cr) from matching */
 224         if (len > 0 && line[len-1] == '\n') {
 225                 if (len > 1 && line[len-2] == '\r')
 226                         len -= 2;
 227                 else
 228                         len--;
 229         }
 230
 231         for (i = 0; i < regs->nr; i++) {
 232                 struct ff_reg *reg = regs->array + i;
 233                 if (!regexec_buf(&reg->re, line, len, 2, pmatch, 0)) {
 234                         if (reg->negate)
 235                                 return -1;
 236                         break;
 237                 }
 238         }
 239         if (regs->nr <= i)
 240                 return -1;
 241         i = pmatch[1].rm_so >= 0 ? 1 : 0;
 242         line += pmatch[i].rm_so;
 243         result = pmatch[i].rm_eo - pmatch[i].rm_so;
 244         if (result > buffer_size)
 245                 result = buffer_size;
 246         while (result > 0 && (isspace(line[result - 1])))
 247                 result--;
 248         memcpy(buffer, line, result);
 249         return result;
 250 }
 251
 252 void xdiff_set_find_func(xdemitconf_t *xecfg, const char *value, int cflags)
 253 {
 254         int i;
 255         struct ff_regs *regs;
 256
 257         xecfg->find_func = ff_regexp;
 258         regs = xecfg->find_func_priv = xmalloc(sizeof(struct ff_regs));
 259         for (i = 0, regs->nr = 1; value[i]; i++)
 260                 if (value[i] == '\n')
 261                         regs->nr++;
 262         ALLOC_ARRAY(regs->array, regs->nr);
 263         for (i = 0; i < regs->nr; i++) {
 264                 struct ff_reg *reg = regs->array + i;
 265                 const char *ep = strchr(value, '\n'), *expression;
 266                 char *buffer = NULL;
 267
 268                 reg->negate = (*value == '!');
 269                 if (reg->negate && i == regs->nr - 1)
 270                         die("Last expression must not be negated: %s", value);
 271                 if (*value == '!')
 272                         value++;
 273                 if (ep)
 274                         expression = buffer = xstrndup(value, ep - value);
 275                 else
 276                         expression = value;
 277                 if (regcomp(&reg->re, expression, cflags))
 278                         die("Invalid regexp to look for hunk header: %s", expression);
 279                 free(buffer);
 280                 value = ep + 1;
 281         }
 282 }
 283
 284 void xdiff_clear_find_func(xdemitconf_t *xecfg)
 285 {
 286         if (xecfg->find_func) {
 287                 int i;
 288                 struct ff_regs *regs = xecfg->find_func_priv;
 289
 290                 for (i = 0; i < regs->nr; i++)
 291                         regfree(&regs->array[i].re);
 292                 free(regs->array);
 293                 free(regs);
 294                 xecfg->find_func = NULL;
 295                 xecfg->find_func_priv = NULL;
 296         }
 297 }
 298
 299 int git_xmerge_style = -1;
 300
 301 int git_xmerge_config(const char *var, const char *value, void *cb)
 302 {
 303         if (!strcmp(var, "merge.conflictstyle")) {
 304                 if (!value)
 305                         die("'%s' is not a boolean", var);
 306                 if (!strcmp(value, "diff3"))
 307                         git_xmerge_style = XDL_MERGE_DIFF3;
 308                 else if (!strcmp(value, "merge"))
 309                         git_xmerge_style = 0;
 310                 else
 311                         die("unknown style '%s' given for '%s'",
 312                             value, var);
 313                 return 0;
 314         }
 315         return git_default_config(var, value, cb);
 316 }