Andrew's git - gitweb.git/blob

   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        if (!priv->line_fn)
  99                return 0;
 100
 101        for (i = 0; i < nbuf; i++) {
 102                if (mb[i].ptr[mb[i].size-1] != '\n') {
 103                        /* Incomplete line */
 104                        strbuf_add(&priv->remainder, mb[i].ptr, mb[i].size);
 105                        continue;
 106                }
 107
 108                /* we have a complete line */
 109                if (!priv->remainder.len) {
 110                        consume_one(priv, mb[i].ptr, mb[i].size);
 111                        continue;
 112                }
 113                strbuf_add(&priv->remainder, mb[i].ptr, mb[i].size);
 114                consume_one(priv, priv->remainder.buf, priv->remainder.len);
 115                strbuf_reset(&priv->remainder);
 116        }
 117        if (priv->remainder.len) {
 118                consume_one(priv, priv->remainder.buf, priv->remainder.len);
 119                strbuf_reset(&priv->remainder);
 120        }
 121        return 0;
 122}
 123
 124/*
 125 * Trim down common substring at the end of the buffers,
 126 * but end on a complete line.
 127 */
 128static void trim_common_tail(mmfile_t *a, mmfile_t *b)
 129{
 130        const int blk = 1024;
 131        long trimmed = 0, recovered = 0;
 132        char *ap = a->ptr + a->size;
 133        char *bp = b->ptr + b->size;
 134        long smaller = (a->size < b->size) ? a->size : b->size;
 135
 136        while (blk + trimmed <= smaller && !memcmp(ap - blk, bp - blk, blk)) {
 137                trimmed += blk;
 138                ap -= blk;
 139                bp -= blk;
 140        }
 141
 142        while (recovered < trimmed)
 143                if (ap[recovered++] == '\n')
 144                        break;
 145        a->size -= trimmed - recovered;
 146        b->size -= trimmed - recovered;
 147}
 148
 149int xdi_diff(mmfile_t *mf1, mmfile_t *mf2, xpparam_t const *xpp, xdemitconf_t const *xecfg, xdemitcb_t *xecb)
 150{
 151        mmfile_t a = *mf1;
 152        mmfile_t b = *mf2;
 153
 154        if (mf1->size > MAX_XDIFF_SIZE || mf2->size > MAX_XDIFF_SIZE)
 155                return -1;
 156
 157        if (!xecfg->ctxlen && !(xecfg->flags & XDL_EMIT_FUNCCONTEXT))
 158                trim_common_tail(&a, &b);
 159
 160        return xdl_diff(&a, &b, xpp, xecfg, xecb);
 161}
 162
 163void discard_hunk_line(void *priv,
 164                       long ob, long on, long nb, long nn,
 165                       const char *func, long funclen)
 166{
 167}
 168
 169int xdi_diff_outf(mmfile_t *mf1, mmfile_t *mf2,
 170                  xdiff_emit_hunk_fn hunk_fn,
 171                  xdiff_emit_line_fn line_fn,
 172                  void *consume_callback_data,
 173                  xpparam_t const *xpp, xdemitconf_t const *xecfg)
 174{
 175        int ret;
 176        struct xdiff_emit_state state;
 177        xdemitcb_t ecb;
 178
 179        memset(&state, 0, sizeof(state));
 180        state.hunk_fn = hunk_fn;
 181        state.line_fn = line_fn;
 182        state.consume_callback_data = consume_callback_data;
 183        memset(&ecb, 0, sizeof(ecb));
 184        if (hunk_fn)
 185                ecb.out_hunk = xdiff_out_hunk;
 186        ecb.out_line = xdiff_outf;
 187        ecb.priv = &state;
 188        strbuf_init(&state.remainder, 0);
 189        ret = xdi_diff(mf1, mf2, xpp, xecfg, &ecb);
 190        strbuf_release(&state.remainder);
 191        return ret;
 192}
 193
 194int read_mmfile(mmfile_t *ptr, const char *filename)
 195{
 196        struct stat st;
 197        FILE *f;
 198        size_t sz;
 199
 200        if (stat(filename, &st))
 201                return error_errno("Could not stat %s", filename);
 202        if ((f = fopen(filename, "rb")) == NULL)
 203                return error_errno("Could not open %s", filename);
 204        sz = xsize_t(st.st_size);
 205        ptr->ptr = xmalloc(sz ? sz : 1);
 206        if (sz && fread(ptr->ptr, sz, 1, f) != 1) {
 207                fclose(f);
 208                return error("Could not read %s", filename);
 209        }
 210        fclose(f);
 211        ptr->size = sz;
 212        return 0;
 213}
 214
 215void read_mmblob(mmfile_t *ptr, const struct object_id *oid)
 216{
 217        unsigned long size;
 218        enum object_type type;
 219
 220        if (!oidcmp(oid, &null_oid)) {
 221                ptr->ptr = xstrdup("");
 222                ptr->size = 0;
 223                return;
 224        }
 225
 226        ptr->ptr = read_object_file(oid, &type, &size);
 227        if (!ptr->ptr || type != OBJ_BLOB)
 228                die("unable to read blob object %s", oid_to_hex(oid));
 229        ptr->size = size;
 230}
 231
 232#define FIRST_FEW_BYTES 8000
 233int buffer_is_binary(const char *ptr, unsigned long size)
 234{
 235        if (FIRST_FEW_BYTES < size)
 236                size = FIRST_FEW_BYTES;
 237        return !!memchr(ptr, 0, size);
 238}
 239
 240struct ff_regs {
 241        int nr;
 242        struct ff_reg {
 243                regex_t re;
 244                int negate;
 245        } *array;
 246};
 247
 248static long ff_regexp(const char *line, long len,
 249                char *buffer, long buffer_size, void *priv)
 250{
 251        struct ff_regs *regs = priv;
 252        regmatch_t pmatch[2];
 253        int i;
 254        int result;
 255
 256        /* Exclude terminating newline (and cr) from matching */
 257        if (len > 0 && line[len-1] == '\n') {
 258                if (len > 1 && line[len-2] == '\r')
 259                        len -= 2;
 260                else
 261                        len--;
 262        }
 263
 264        for (i = 0; i < regs->nr; i++) {
 265                struct ff_reg *reg = regs->array + i;
 266                if (!regexec_buf(&reg->re, line, len, 2, pmatch, 0)) {
 267                        if (reg->negate)
 268                                return -1;
 269                        break;
 270                }
 271        }
 272        if (regs->nr <= i)
 273                return -1;
 274        i = pmatch[1].rm_so >= 0 ? 1 : 0;
 275        line += pmatch[i].rm_so;
 276        result = pmatch[i].rm_eo - pmatch[i].rm_so;
 277        if (result > buffer_size)
 278                result = buffer_size;
 279        while (result > 0 && (isspace(line[result - 1])))
 280                result--;
 281        memcpy(buffer, line, result);
 282        return result;
 283}
 284
 285void xdiff_set_find_func(xdemitconf_t *xecfg, const char *value, int cflags)
 286{
 287        int i;
 288        struct ff_regs *regs;
 289
 290        xecfg->find_func = ff_regexp;
 291        regs = xecfg->find_func_priv = xmalloc(sizeof(struct ff_regs));
 292        for (i = 0, regs->nr = 1; value[i]; i++)
 293                if (value[i] == '\n')
 294                        regs->nr++;
 295        ALLOC_ARRAY(regs->array, regs->nr);
 296        for (i = 0; i < regs->nr; i++) {
 297                struct ff_reg *reg = regs->array + i;
 298                const char *ep = strchr(value, '\n'), *expression;
 299                char *buffer = NULL;
 300
 301                reg->negate = (*value == '!');
 302                if (reg->negate && i == regs->nr - 1)
 303                        die("Last expression must not be negated: %s", value);
 304                if (*value == '!')
 305                        value++;
 306                if (ep)
 307                        expression = buffer = xstrndup(value, ep - value);
 308                else
 309                        expression = value;
 310                if (regcomp(&reg->re, expression, cflags))
 311                        die("Invalid regexp to look for hunk header: %s", expression);
 312                free(buffer);
 313                value = ep + 1;
 314        }
 315}
 316
 317void xdiff_clear_find_func(xdemitconf_t *xecfg)
 318{
 319        if (xecfg->find_func) {
 320                int i;
 321                struct ff_regs *regs = xecfg->find_func_priv;
 322
 323                for (i = 0; i < regs->nr; i++)
 324                        regfree(&regs->array[i].re);
 325                free(regs->array);
 326                free(regs);
 327                xecfg->find_func = NULL;
 328                xecfg->find_func_priv = NULL;
 329        }
 330}
 331
 332unsigned long xdiff_hash_string(const char *s, size_t len, long flags)
 333{
 334        return xdl_hash_record(&s, s + len, flags);
 335}
 336
 337int xdiff_compare_lines(const char *l1, long s1,
 338                        const char *l2, long s2, long flags)
 339{
 340        return xdl_recmatch(l1, s1, l2, s2, flags);
 341}
 342
 343int git_xmerge_style = -1;
 344
 345int git_xmerge_config(const char *var, const char *value, void *cb)
 346{
 347        if (!strcmp(var, "merge.conflictstyle")) {
 348                if (!value)
 349                        die("'%s' is not a boolean", var);
 350                if (!strcmp(value, "diff3"))
 351                        git_xmerge_style = XDL_MERGE_DIFF3;
 352                else if (!strcmp(value, "merge"))
 353                        git_xmerge_style = 0;
 354                else
 355                        die("unknown style '%s' given for '%s'",
 356                            value, var);
 357                return 0;
 358        }
 359        return git_default_config(var, value, cb);
 360}