Andrew's git - gitweb.git/blob

eb9c05a1e34d6d9921bcb379ff0bdf7fe6c643bf
   1#include "cache.h"
   2#include "config.h"
   3#include "object-store.h"
   4#include "xdiff-interface.h"
   5#include "xdiff/xtypes.h"
   6#include "xdiff/xdiffi.h"
   7#include "xdiff/xemit.h"
   8#include "xdiff/xmacros.h"
   9#include "xdiff/xutils.h"
  10
  11struct xdiff_emit_state {
  12        xdiff_emit_hunk_fn hunk_fn;
  13        xdiff_emit_line_fn line_fn;
  14        void *consume_callback_data;
  15        struct strbuf remainder;
  16};
  17
  18static int parse_num(char **cp_p, int *num_p)
  19{
  20        char *cp = *cp_p;
  21        int num = 0;
  22
  23        while ('0' <= *cp && *cp <= '9')
  24                num = num * 10 + *cp++ - '0';
  25        if (!(cp - *cp_p))
  26                return -1;
  27        *cp_p = cp;
  28        *num_p = num;
  29        return 0;
  30}
  31
  32int parse_hunk_header(char *line, int len,
  33                      int *ob, int *on,
  34                      int *nb, int *nn)
  35{
  36        char *cp;
  37        cp = line + 4;
  38        if (parse_num(&cp, ob)) {
  39        bad_line:
  40                return error("malformed diff output: %s", line);
  41        }
  42        if (*cp == ',') {
  43                cp++;
  44                if (parse_num(&cp, on))
  45                        goto bad_line;
  46        }
  47        else
  48                *on = 1;
  49        if (*cp++ != ' ' || *cp++ != '+')
  50                goto bad_line;
  51        if (parse_num(&cp, nb))
  52                goto bad_line;
  53        if (*cp == ',') {
  54                cp++;
  55                if (parse_num(&cp, nn))
  56                        goto bad_line;
  57        }
  58        else
  59                *nn = 1;
  60        return -!!memcmp(cp, " @@", 3);
  61}
  62
  63static int xdiff_out_hunk(void *priv_,
  64                          long old_begin, long old_nr,
  65                          long new_begin, long new_nr,
  66                          const char *func, long funclen)
  67{
  68        struct xdiff_emit_state *priv = priv_;
  69
  70        if (priv->remainder.len)
  71                BUG("xdiff emitted hunk in the middle of a line");
  72
  73        priv->hunk_fn(priv->consume_callback_data,
  74                      old_begin, old_nr, new_begin, new_nr,
  75                      func, funclen);
  76        return 0;
  77}
  78
  79static void consume_one(void *priv_, char *s, unsigned long size)
  80{
  81        struct xdiff_emit_state *priv = priv_;
  82        char *ep;
  83        while (size) {
  84                unsigned long this_size;
  85                ep = memchr(s, '\n', size);
  86                this_size = (ep == NULL) ? size : (ep - s + 1);
  87                priv->line_fn(priv->consume_callback_data, s, this_size);
  88                size -= this_size;
  89                s += this_size;
  90        }
  91}
  92
  93static int xdiff_outf(void *priv_, mmbuffer_t *mb, int nbuf)
  94{
  95        struct xdiff_emit_state *priv = priv_;
  96        int i;
  97
  98        for (i = 0; i < nbuf; i++) {
  99                if (mb[i].ptr[mb[i].size-1] != '\n') {
 100                        /* Incomplete line */
 101                        strbuf_add(&priv->remainder, mb[i].ptr, mb[i].size);
 102                        continue;
 103                }
 104
 105                /* we have a complete line */
 106                if (!priv->remainder.len) {
 107                        consume_one(priv, mb[i].ptr, mb[i].size);
 108                        continue;
 109                }
 110                strbuf_add(&priv->remainder, mb[i].ptr, mb[i].size);
 111                consume_one(priv, priv->remainder.buf, priv->remainder.len);
 112                strbuf_reset(&priv->remainder);
 113        }
 114        if (priv->remainder.len) {
 115                consume_one(priv, priv->remainder.buf, priv->remainder.len);
 116                strbuf_reset(&priv->remainder);
 117        }
 118        return 0;
 119}
 120
 121/*
 122 * Trim down common substring at the end of the buffers,
 123 * but end on a complete line.
 124 */
 125static void trim_common_tail(mmfile_t *a, mmfile_t *b)
 126{
 127        const int blk = 1024;
 128        long trimmed = 0, recovered = 0;
 129        char *ap = a->ptr + a->size;
 130        char *bp = b->ptr + b->size;
 131        long smaller = (a->size < b->size) ? a->size : b->size;
 132
 133        while (blk + trimmed <= smaller && !memcmp(ap - blk, bp - blk, blk)) {
 134                trimmed += blk;
 135                ap -= blk;
 136                bp -= blk;
 137        }
 138
 139        while (recovered < trimmed)
 140                if (ap[recovered++] == '\n')
 141                        break;
 142        a->size -= trimmed - recovered;
 143        b->size -= trimmed - recovered;
 144}
 145
 146int xdi_diff(mmfile_t *mf1, mmfile_t *mf2, xpparam_t const *xpp, xdemitconf_t const *xecfg, xdemitcb_t *xecb)
 147{
 148        mmfile_t a = *mf1;
 149        mmfile_t b = *mf2;
 150
 151        if (mf1->size > MAX_XDIFF_SIZE || mf2->size > MAX_XDIFF_SIZE)
 152                return -1;
 153
 154        if (!xecfg->ctxlen && !(xecfg->flags & XDL_EMIT_FUNCCONTEXT))
 155                trim_common_tail(&a, &b);
 156
 157        return xdl_diff(&a, &b, xpp, xecfg, xecb);
 158}
 159
 160int xdi_diff_outf(mmfile_t *mf1, mmfile_t *mf2,
 161                  xdiff_emit_hunk_fn hunk_fn,
 162                  xdiff_emit_line_fn line_fn,
 163                  void *consume_callback_data,
 164                  xpparam_t const *xpp, xdemitconf_t const *xecfg)
 165{
 166        int ret;
 167        struct xdiff_emit_state state;
 168        xdemitcb_t ecb;
 169
 170        memset(&state, 0, sizeof(state));
 171        state.hunk_fn = hunk_fn;
 172        state.line_fn = line_fn;
 173        state.consume_callback_data = consume_callback_data;
 174        memset(&ecb, 0, sizeof(ecb));
 175        if (hunk_fn)
 176                ecb.out_hunk = xdiff_out_hunk;
 177        ecb.out_line = xdiff_outf;
 178        ecb.priv = &state;
 179        strbuf_init(&state.remainder, 0);
 180        ret = xdi_diff(mf1, mf2, xpp, xecfg, &ecb);
 181        strbuf_release(&state.remainder);
 182        return ret;
 183}
 184
 185int read_mmfile(mmfile_t *ptr, const char *filename)
 186{
 187        struct stat st;
 188        FILE *f;
 189        size_t sz;
 190
 191        if (stat(filename, &st))
 192                return error_errno("Could not stat %s", filename);
 193        if ((f = fopen(filename, "rb")) == NULL)
 194                return error_errno("Could not open %s", filename);
 195        sz = xsize_t(st.st_size);
 196        ptr->ptr = xmalloc(sz ? sz : 1);
 197        if (sz && fread(ptr->ptr, sz, 1, f) != 1) {
 198                fclose(f);
 199                return error("Could not read %s", filename);
 200        }
 201        fclose(f);
 202        ptr->size = sz;
 203        return 0;
 204}
 205
 206void read_mmblob(mmfile_t *ptr, const struct object_id *oid)
 207{
 208        unsigned long size;
 209        enum object_type type;
 210
 211        if (!oidcmp(oid, &null_oid)) {
 212                ptr->ptr = xstrdup("");
 213                ptr->size = 0;
 214                return;
 215        }
 216
 217        ptr->ptr = read_object_file(oid, &type, &size);
 218        if (!ptr->ptr || type != OBJ_BLOB)
 219                die("unable to read blob object %s", oid_to_hex(oid));
 220        ptr->size = size;
 221}
 222
 223#define FIRST_FEW_BYTES 8000
 224int buffer_is_binary(const char *ptr, unsigned long size)
 225{
 226        if (FIRST_FEW_BYTES < size)
 227                size = FIRST_FEW_BYTES;
 228        return !!memchr(ptr, 0, size);
 229}
 230
 231struct ff_regs {
 232        int nr;
 233        struct ff_reg {
 234                regex_t re;
 235                int negate;
 236        } *array;
 237};
 238
 239static long ff_regexp(const char *line, long len,
 240                char *buffer, long buffer_size, void *priv)
 241{
 242        struct ff_regs *regs = priv;
 243        regmatch_t pmatch[2];
 244        int i;
 245        int result;
 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        for (i = 0; i < regs->nr; i++) {
 256                struct ff_reg *reg = regs->array + i;
 257                if (!regexec_buf(&reg->re, line, len, 2, pmatch, 0)) {
 258                        if (reg->negate)
 259                                return -1;
 260                        break;
 261                }
 262        }
 263        if (regs->nr <= i)
 264                return -1;
 265        i = pmatch[1].rm_so >= 0 ? 1 : 0;
 266        line += pmatch[i].rm_so;
 267        result = pmatch[i].rm_eo - pmatch[i].rm_so;
 268        if (result > buffer_size)
 269                result = buffer_size;
 270        while (result > 0 && (isspace(line[result - 1])))
 271                result--;
 272        memcpy(buffer, line, result);
 273        return result;
 274}
 275
 276void xdiff_set_find_func(xdemitconf_t *xecfg, const char *value, int cflags)
 277{
 278        int i;
 279        struct ff_regs *regs;
 280
 281        xecfg->find_func = ff_regexp;
 282        regs = xecfg->find_func_priv = xmalloc(sizeof(struct ff_regs));
 283        for (i = 0, regs->nr = 1; value[i]; i++)
 284                if (value[i] == '\n')
 285                        regs->nr++;
 286        ALLOC_ARRAY(regs->array, regs->nr);
 287        for (i = 0; i < regs->nr; i++) {
 288                struct ff_reg *reg = regs->array + i;
 289                const char *ep = strchr(value, '\n'), *expression;
 290                char *buffer = NULL;
 291
 292                reg->negate = (*value == '!');
 293                if (reg->negate && i == regs->nr - 1)
 294                        die("Last expression must not be negated: %s", value);
 295                if (*value == '!')
 296                        value++;
 297                if (ep)
 298                        expression = buffer = xstrndup(value, ep - value);
 299                else
 300                        expression = value;
 301                if (regcomp(&reg->re, expression, cflags))
 302                        die("Invalid regexp to look for hunk header: %s", expression);
 303                free(buffer);
 304                value = ep + 1;
 305        }
 306}
 307
 308void xdiff_clear_find_func(xdemitconf_t *xecfg)
 309{
 310        if (xecfg->find_func) {
 311                int i;
 312                struct ff_regs *regs = xecfg->find_func_priv;
 313
 314                for (i = 0; i < regs->nr; i++)
 315                        regfree(&regs->array[i].re);
 316                free(regs->array);
 317                free(regs);
 318                xecfg->find_func = NULL;
 319                xecfg->find_func_priv = NULL;
 320        }
 321}
 322
 323unsigned long xdiff_hash_string(const char *s, size_t len, long flags)
 324{
 325        return xdl_hash_record(&s, s + len, flags);
 326}
 327
 328int xdiff_compare_lines(const char *l1, long s1,
 329                        const char *l2, long s2, long flags)
 330{
 331        return xdl_recmatch(l1, s1, l2, s2, flags);
 332}
 333
 334int git_xmerge_style = -1;
 335
 336int git_xmerge_config(const char *var, const char *value, void *cb)
 337{
 338        if (!strcmp(var, "merge.conflictstyle")) {
 339                if (!value)
 340                        die("'%s' is not a boolean", var);
 341                if (!strcmp(value, "diff3"))
 342                        git_xmerge_style = XDL_MERGE_DIFF3;
 343                else if (!strcmp(value, "merge"))
 344                        git_xmerge_style = 0;
 345                else
 346                        die("unknown style '%s' given for '%s'",
 347                            value, var);
 348                return 0;
 349        }
 350        return git_default_config(var, value, cb);
 351}