Andrew's git - gitweb.git/blob

   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
   8struct xdiff_emit_state {
   9        xdiff_emit_consume_fn consume;
  10        void *consume_callback_data;
  11        struct strbuf remainder;
  12};
  13
  14static int parse_num(char **cp_p, int *num_p)
  15{
  16        char *cp = *cp_p;
  17        int num = 0;
  18
  19        while ('0' <= *cp && *cp <= '9')
  20                num = num * 10 + *cp++ - '0';
  21        if (!(cp - *cp_p))
  22                return -1;
  23        *cp_p = cp;
  24        *num_p = num;
  25        return 0;
  26}
  27
  28int parse_hunk_header(char *line, int len,
  29                      int *ob, int *on,
  30                      int *nb, int *nn)
  31{
  32        char *cp;
  33        cp = line + 4;
  34        if (parse_num(&cp, ob)) {
  35        bad_line:
  36                return error("malformed diff output: %s", line);
  37        }
  38        if (*cp == ',') {
  39                cp++;
  40                if (parse_num(&cp, on))
  41                        goto bad_line;
  42        }
  43        else
  44                *on = 1;
  45        if (*cp++ != ' ' || *cp++ != '+')
  46                goto bad_line;
  47        if (parse_num(&cp, nb))
  48                goto bad_line;
  49        if (*cp == ',') {
  50                cp++;
  51                if (parse_num(&cp, nn))
  52                        goto bad_line;
  53        }
  54        else
  55                *nn = 1;
  56        return -!!memcmp(cp, " @@", 3);
  57}
  58
  59static void consume_one(void *priv_, char *s, unsigned long size)
  60{
  61        struct xdiff_emit_state *priv = priv_;
  62        char *ep;
  63        while (size) {
  64                unsigned long this_size;
  65                ep = memchr(s, '\n', size);
  66                this_size = (ep == NULL) ? size : (ep - s + 1);
  67                priv->consume(priv->consume_callback_data, s, this_size);
  68                size -= this_size;
  69                s += this_size;
  70        }
  71}
  72
  73static int xdiff_outf(void *priv_, mmbuffer_t *mb, int nbuf)
  74{
  75        struct xdiff_emit_state *priv = priv_;
  76        int i;
  77
  78        for (i = 0; i < nbuf; i++) {
  79                if (mb[i].ptr[mb[i].size-1] != '\n') {
  80                        /* Incomplete line */
  81                        strbuf_add(&priv->remainder, mb[i].ptr, mb[i].size);
  82                        continue;
  83                }
  84
  85                /* we have a complete line */
  86                if (!priv->remainder.len) {
  87                        consume_one(priv, mb[i].ptr, mb[i].size);
  88                        continue;
  89                }
  90                strbuf_add(&priv->remainder, mb[i].ptr, mb[i].size);
  91                consume_one(priv, priv->remainder.buf, priv->remainder.len);
  92                strbuf_reset(&priv->remainder);
  93        }
  94        if (priv->remainder.len) {
  95                consume_one(priv, priv->remainder.buf, priv->remainder.len);
  96                strbuf_reset(&priv->remainder);
  97        }
  98        return 0;
  99}
 100
 101/*
 102 * Trim down common substring at the end of the buffers,
 103 * but end on a complete line.
 104 */
 105static void trim_common_tail(mmfile_t *a, mmfile_t *b)
 106{
 107        const int blk = 1024;
 108        long trimmed = 0, recovered = 0;
 109        char *ap = a->ptr + a->size;
 110        char *bp = b->ptr + b->size;
 111        long smaller = (a->size < b->size) ? a->size : b->size;
 112
 113        while (blk + trimmed <= smaller && !memcmp(ap - blk, bp - blk, blk)) {
 114                trimmed += blk;
 115                ap -= blk;
 116                bp -= blk;
 117        }
 118
 119        while (recovered < trimmed)
 120                if (ap[recovered++] == '\n')
 121                        break;
 122        a->size -= trimmed - recovered;
 123        b->size -= trimmed - recovered;
 124}
 125
 126int xdi_diff(mmfile_t *mf1, mmfile_t *mf2, xpparam_t const *xpp, xdemitconf_t const *xecfg, xdemitcb_t *xecb)
 127{
 128        mmfile_t a = *mf1;
 129        mmfile_t b = *mf2;
 130
 131        if (mf1->size > MAX_XDIFF_SIZE || mf2->size > MAX_XDIFF_SIZE)
 132                return -1;
 133
 134        if (!xecfg->ctxlen && !(xecfg->flags & XDL_EMIT_FUNCCONTEXT))
 135                trim_common_tail(&a, &b);
 136
 137        return xdl_diff(&a, &b, xpp, xecfg, xecb);
 138}
 139
 140int xdi_diff_outf(mmfile_t *mf1, mmfile_t *mf2,
 141                  xdiff_emit_consume_fn fn, void *consume_callback_data,
 142                  xpparam_t const *xpp, xdemitconf_t const *xecfg)
 143{
 144        int ret;
 145        struct xdiff_emit_state state;
 146        xdemitcb_t ecb;
 147
 148        memset(&state, 0, sizeof(state));
 149        state.consume = fn;
 150        state.consume_callback_data = consume_callback_data;
 151        memset(&ecb, 0, sizeof(ecb));
 152        ecb.outf = xdiff_outf;
 153        ecb.priv = &state;
 154        strbuf_init(&state.remainder, 0);
 155        ret = xdi_diff(mf1, mf2, xpp, xecfg, &ecb);
 156        strbuf_release(&state.remainder);
 157        return ret;
 158}
 159
 160int read_mmfile(mmfile_t *ptr, const char *filename)
 161{
 162        struct stat st;
 163        FILE *f;
 164        size_t sz;
 165
 166        if (stat(filename, &st))
 167                return error("Could not stat %s", filename);
 168        if ((f = fopen(filename, "rb")) == NULL)
 169                return error("Could not open %s", filename);
 170        sz = xsize_t(st.st_size);
 171        ptr->ptr = xmalloc(sz ? sz : 1);
 172        if (sz && fread(ptr->ptr, sz, 1, f) != 1) {
 173                fclose(f);
 174                return error("Could not read %s", filename);
 175        }
 176        fclose(f);
 177        ptr->size = sz;
 178        return 0;
 179}
 180
 181void read_mmblob(mmfile_t *ptr, const unsigned char *sha1)
 182{
 183        unsigned long size;
 184        enum object_type type;
 185
 186        if (!hashcmp(sha1, null_sha1)) {
 187                ptr->ptr = xstrdup("");
 188                ptr->size = 0;
 189                return;
 190        }
 191
 192        ptr->ptr = read_sha1_file(sha1, &type, &size);
 193        if (!ptr->ptr || type != OBJ_BLOB)
 194                die("unable to read blob object %s", sha1_to_hex(sha1));
 195        ptr->size = size;
 196}
 197
 198#define FIRST_FEW_BYTES 8000
 199int buffer_is_binary(const char *ptr, unsigned long size)
 200{
 201        if (FIRST_FEW_BYTES < size)
 202                size = FIRST_FEW_BYTES;
 203        return !!memchr(ptr, 0, size);
 204}
 205
 206struct ff_regs {
 207        int nr;
 208        struct ff_reg {
 209                regex_t re;
 210                int negate;
 211        } *array;
 212};
 213
 214static long ff_regexp(const char *line, long len,
 215                char *buffer, long buffer_size, void *priv)
 216{
 217        char *line_buffer;
 218        struct ff_regs *regs = priv;
 219        regmatch_t pmatch[2];
 220        int i;
 221        int result = -1;
 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        line_buffer = xstrndup(line, len); /* make NUL terminated */
 232
 233        for (i = 0; i < regs->nr; i++) {
 234                struct ff_reg *reg = regs->array + i;
 235                if (!regexec(&reg->re, line_buffer, 2, pmatch, 0)) {
 236                        if (reg->negate)
 237                                goto fail;
 238                        break;
 239                }
 240        }
 241        if (regs->nr <= i)
 242                goto fail;
 243        i = pmatch[1].rm_so >= 0 ? 1 : 0;
 244        line += pmatch[i].rm_so;
 245        result = pmatch[i].rm_eo - pmatch[i].rm_so;
 246        if (result > buffer_size)
 247                result = buffer_size;
 248        while (result > 0 && (isspace(line[result - 1])))
 249                result--;
 250        memcpy(buffer, line, result);
 251 fail:
 252        free(line_buffer);
 253        return result;
 254}
 255
 256void xdiff_set_find_func(xdemitconf_t *xecfg, const char *value, int cflags)
 257{
 258        int i;
 259        struct ff_regs *regs;
 260
 261        xecfg->find_func = ff_regexp;
 262        regs = xecfg->find_func_priv = xmalloc(sizeof(struct ff_regs));
 263        for (i = 0, regs->nr = 1; value[i]; i++)
 264                if (value[i] == '\n')
 265                        regs->nr++;
 266        ALLOC_ARRAY(regs->array, regs->nr);
 267        for (i = 0; i < regs->nr; i++) {
 268                struct ff_reg *reg = regs->array + i;
 269                const char *ep = strchr(value, '\n'), *expression;
 270                char *buffer = NULL;
 271
 272                reg->negate = (*value == '!');
 273                if (reg->negate && i == regs->nr - 1)
 274                        die("Last expression must not be negated: %s", value);
 275                if (*value == '!')
 276                        value++;
 277                if (ep)
 278                        expression = buffer = xstrndup(value, ep - value);
 279                else
 280                        expression = value;
 281                if (regcomp(&reg->re, expression, cflags))
 282                        die("Invalid regexp to look for hunk header: %s", expression);
 283                free(buffer);
 284                value = ep + 1;
 285        }
 286}
 287
 288void xdiff_clear_find_func(xdemitconf_t *xecfg)
 289{
 290        if (xecfg->find_func) {
 291                int i;
 292                struct ff_regs *regs = xecfg->find_func_priv;
 293
 294                for (i = 0; i < regs->nr; i++)
 295                        regfree(&regs->array[i].re);
 296                free(regs->array);
 297                free(regs);
 298                xecfg->find_func = NULL;
 299                xecfg->find_func_priv = NULL;
 300        }
 301}
 302
 303int git_xmerge_style = -1;
 304
 305int git_xmerge_config(const char *var, const char *value, void *cb)
 306{
 307        if (!strcmp(var, "merge.conflictstyle")) {
 308                if (!value)
 309                        die("'%s' is not a boolean", var);
 310                if (!strcmp(value, "diff3"))
 311                        git_xmerge_style = XDL_MERGE_DIFF3;
 312                else if (!strcmp(value, "merge"))
 313                        git_xmerge_style = 0;
 314                else
 315                        die("unknown style '%s' given for '%s'",
 316                            value, var);
 317                return 0;
 318        }
 319        return git_default_config(var, value, cb);
 320}