Andrew's git - gitweb.git/blob

   1#include "cache.h"
   2#include "commit.h"
   3#include "diff.h"
   4#include "diffcore.h"
   5#include "quote.h"
   6
   7struct path_list {
   8        struct path_list *next;
   9        int len;
  10        char *path;
  11        unsigned char sha1[20];
  12        unsigned char parent_sha1[FLEX_ARRAY][20];
  13};
  14
  15static int uninteresting(struct diff_filepair *p)
  16{
  17        if (diff_unmodified_pair(p))
  18                return 1;
  19        if (!S_ISREG(p->one->mode) || !S_ISREG(p->two->mode))
  20                return 1;
  21        return 0;
  22}
  23
  24static struct path_list *intersect_paths(struct path_list *curr,
  25                                         int n, int num_parent)
  26{
  27        struct diff_queue_struct *q = &diff_queued_diff;
  28        struct path_list *p;
  29        int i;
  30
  31        if (!n) {
  32                struct path_list *list = NULL, *tail = NULL;
  33                for (i = 0; i < q->nr; i++) {
  34                        int len;
  35                        const char *path;
  36                        if (uninteresting(q->queue[i]))
  37                                continue;
  38                        path = q->queue[i]->two->path;
  39                        len = strlen(path);
  40
  41                        p = xmalloc(sizeof(*p) + len + 1 + num_parent * 20);
  42                        p->path = (char*) &(p->parent_sha1[num_parent][0]);
  43                        memcpy(p->path, path, len);
  44                        p->path[len] = 0;
  45                        p->len = len;
  46                        p->next = NULL;
  47                        memcpy(p->sha1, q->queue[i]->two->sha1, 20);
  48                        memcpy(p->parent_sha1[n], q->queue[i]->one->sha1, 20);
  49                        if (!tail)
  50                                list = tail = p;
  51                        else {
  52                                tail->next = p;
  53                                p = tail;
  54                        }
  55                }
  56                return list;
  57        }
  58
  59        for (p = curr; p; p = p->next) {
  60                int found = 0;
  61                if (!p->len)
  62                        continue;
  63                for (i = 0; i < q->nr; i++) {
  64                        const char *path;
  65                        int len;
  66
  67                        if (uninteresting(q->queue[i]))
  68                                continue;
  69                        path = q->queue[i]->two->path;
  70                        len = strlen(path);
  71                        if (len == p->len && !memcmp(path, p->path, len)) {
  72                                found = 1;
  73                                memcpy(p->parent_sha1[n],
  74                                       q->queue[i]->one->sha1, 20);
  75                                break;
  76                        }
  77                }
  78                if (!found)
  79                        p->len = 0;
  80        }
  81        return curr;
  82}
  83
  84struct lline {
  85        struct lline *next;
  86        int len;
  87        unsigned long parent_map;
  88        char line[FLEX_ARRAY];
  89};
  90
  91struct sline {
  92        struct lline *lost_head, **lost_tail;
  93        char *bol;
  94        int len;
  95        unsigned long flag;
  96};
  97
  98static char *grab_blob(const unsigned char *sha1, unsigned long *size)
  99{
 100        char *blob;
 101        char type[20];
 102        if (!memcmp(sha1, null_sha1, 20)) {
 103                /* deleted blob */
 104                *size = 0;
 105                return xcalloc(1, 1);
 106        }
 107        blob = read_sha1_file(sha1, type, size);
 108        if (strcmp(type, "blob"))
 109                die("object '%s' is not a blob!", sha1_to_hex(sha1));
 110        return blob;
 111}
 112
 113#define TMPPATHLEN 50
 114#define MAXLINELEN 10240
 115
 116static void write_to_temp_file(char *tmpfile, void *blob, unsigned long size)
 117{
 118        int fd = git_mkstemp(tmpfile, TMPPATHLEN, ".diff_XXXXXX");
 119        if (fd < 0)
 120                die("unable to create temp-file");
 121        if (write(fd, blob, size) != size)
 122                die("unable to write temp-file");
 123        close(fd);
 124}
 125
 126static void write_temp_blob(char *tmpfile, const unsigned char *sha1)
 127{
 128        unsigned long size;
 129        void *blob;
 130        blob = grab_blob(sha1, &size);
 131        write_to_temp_file(tmpfile, blob, size);
 132        free(blob);
 133}
 134
 135static int parse_num(char **cp_p, unsigned int *num_p)
 136{
 137        char *cp = *cp_p;
 138        unsigned int num = 0;
 139        int read_some;
 140
 141        while ('0' <= *cp && *cp <= '9')
 142                num = num * 10 + *cp++ - '0';
 143        if (!(read_some = cp - *cp_p))
 144                return -1;
 145        *cp_p = cp;
 146        *num_p = num;
 147        return 0;
 148}
 149
 150static int parse_hunk_header(char *line, int len,
 151                             unsigned int *ob, unsigned int *on,
 152                             unsigned int *nb, unsigned int *nn)
 153{
 154        char *cp;
 155        cp = line + 4;
 156        if (parse_num(&cp, ob)) {
 157        bad_line:
 158                return error("malformed diff output: %s", line);
 159        }
 160        if (*cp == ',') {
 161                cp++;
 162                if (parse_num(&cp, on))
 163                        goto bad_line;
 164        }
 165        else
 166                *on = 1;
 167        if (*cp++ != ' ' || *cp++ != '+')
 168                goto bad_line;
 169        if (parse_num(&cp, nb))
 170                goto bad_line;
 171        if (*cp == ',') {
 172                cp++;
 173                if (parse_num(&cp, nn))
 174                        goto bad_line;
 175        }
 176        else
 177                *nn = 1;
 178        return -!!memcmp(cp, " @@", 3);
 179}
 180
 181static void append_lost(struct sline *sline, int n, const char *line)
 182{
 183        struct lline *lline;
 184        int len = strlen(line);
 185        unsigned long this_mask = (1UL<<n);
 186        if (line[len-1] == '\n')
 187                len--;
 188
 189        /* Check to see if we can squash things */
 190        if (sline->lost_head) {
 191                struct lline *last_one = NULL;
 192                /* We cannot squash it with earlier one */
 193                for (lline = sline->lost_head;
 194                     lline;
 195                     lline = lline->next)
 196                        if (lline->parent_map & this_mask)
 197                                last_one = lline;
 198                lline = last_one ? last_one->next : sline->lost_head;
 199                while (lline) {
 200                        if (lline->len == len &&
 201                            !memcmp(lline->line, line, len)) {
 202                                lline->parent_map |= this_mask;
 203                                return;
 204                        }
 205                        lline = lline->next;
 206                }
 207        }
 208
 209        lline = xmalloc(sizeof(*lline) + len + 1);
 210        lline->len = len;
 211        lline->next = NULL;
 212        lline->parent_map = this_mask;
 213        memcpy(lline->line, line, len);
 214        lline->line[len] = 0;
 215        if (sline->lost_head)
 216                *(sline->lost_tail) = lline;
 217        else
 218                sline->lost_head = lline;
 219        sline->lost_tail = &lline->next;
 220}
 221
 222static void combine_diff(const unsigned char *parent, const char *ourtmp,
 223                         struct sline *sline, int cnt, int n)
 224{
 225        FILE *in;
 226        char parent_tmp[TMPPATHLEN];
 227        char cmd[TMPPATHLEN * 2 + 1024];
 228        char line[MAXLINELEN];
 229        unsigned int lno, ob, on, nb, nn;
 230        unsigned long pmask = ~(1UL << n);
 231        struct sline *lost_bucket = NULL;
 232
 233        write_temp_blob(parent_tmp, parent);
 234        sprintf(cmd, "diff --unified=0 -La/x -Lb/x '%s' '%s'",
 235                parent_tmp, ourtmp);
 236        in = popen(cmd, "r");
 237        if (!in)
 238                return;
 239
 240        lno = 1;
 241        while (fgets(line, sizeof(line), in) != NULL) {
 242                int len = strlen(line);
 243                if (5 < len && !memcmp("@@ -", line, 4)) {
 244                        if (parse_hunk_header(line, len,
 245                                              &ob, &on, &nb, &nn))
 246                                break;
 247                        lno = nb;
 248                        if (!nb) {
 249                                /* @@ -1,2 +0,0 @@ to remove the
 250                                 * first two lines...
 251                                 */
 252                                nb = 1;
 253                        }
 254                        lost_bucket = &sline[nb-1]; /* sline is 0 based */
 255                        continue;
 256                }
 257                if (!lost_bucket)
 258                        continue;
 259                switch (line[0]) {
 260                case '-':
 261                        append_lost(lost_bucket, n, line+1);
 262                        break;
 263                case '+':
 264                        sline[lno-1].flag &= pmask;
 265                        lno++;
 266                        break;
 267                }
 268        }
 269        fclose(in);
 270        unlink(parent_tmp);
 271}
 272
 273static unsigned long context = 3;
 274static char combine_marker = '@';
 275
 276static int interesting(struct sline *sline, unsigned long all_mask)
 277{
 278        return ((sline->flag & all_mask) != all_mask || sline->lost_head);
 279}
 280
 281static void make_hunks(struct sline *sline, unsigned long cnt, int num_parent)
 282{
 283        unsigned long all_mask = (1UL<<num_parent) - 1;
 284        unsigned long mark = (1UL<<num_parent);
 285        unsigned long i;
 286
 287        i = 0;
 288        while (i < cnt) {
 289                if (interesting(&sline[i], all_mask)) {
 290                        unsigned long j = (context < i) ? i - context : 0;
 291                        while (j <= i)
 292                                sline[j++].flag |= mark;
 293                        while (++i < cnt) {
 294                                if (!interesting(&sline[i], all_mask))
 295                                        break;
 296                                sline[i].flag |= mark;
 297                        }
 298                        j = (i + context < cnt) ? i + context : cnt;
 299                        while (i < j)
 300                                sline[i++].flag |= mark;
 301                        continue;
 302                }
 303                i++;
 304        }
 305}
 306
 307static void dump_sline(struct sline *sline, int cnt, int num_parent)
 308{
 309        unsigned long mark = (1UL<<num_parent);
 310        int i;
 311        int lno = 0;
 312
 313        while (1) {
 314                struct sline *sl = &sline[lno];
 315                int hunk_end;
 316                while (lno < cnt && !(sline[lno].flag & mark))
 317                        lno++;
 318                if (cnt <= lno)
 319                        break;
 320                for (hunk_end = lno + 1; hunk_end < cnt; hunk_end++)
 321                        if (!(sline[hunk_end].flag & mark))
 322                                break;
 323                for (i = 0; i <= num_parent; i++) putchar(combine_marker);
 324                printf(" +%d,%d ", lno+1, hunk_end-lno);
 325                for (i = 0; i <= num_parent; i++) putchar(combine_marker);
 326                putchar('\n');
 327                while (lno < hunk_end) {
 328                        struct lline *ll;
 329                        int j;
 330                        sl = &sline[lno++];
 331                        ll = sl->lost_head;
 332                        while (ll) {
 333                                for (j = 0; j < num_parent; j++) {
 334                                        if (ll->parent_map & (1UL<<j))
 335                                                putchar('-');
 336                                        else
 337                                                putchar(' ');
 338                                }
 339                                putchar(' ');
 340                                puts(ll->line);
 341                                ll = ll->next;
 342                        }
 343                        for (j = 0; j < num_parent; j++) {
 344                                if ((1UL<<j) & sl->flag)
 345                                        putchar(' ');
 346                                else
 347                                        putchar('+');
 348                        }
 349                        printf(" %.*s\n", sl->len, sl->bol);
 350                }
 351        }
 352}
 353
 354static void show_combined_diff(struct path_list *elem, int num_parent)
 355{
 356        unsigned long size, cnt, lno;
 357        char *result, *cp, *ep;
 358        struct sline *sline; /* survived lines */
 359        int i;
 360        char ourtmp[TMPPATHLEN];
 361
 362        /* Read the result of merge first */
 363        result = grab_blob(elem->sha1, &size);
 364        write_to_temp_file(ourtmp, result, size);
 365
 366        for (cnt = 0, cp = result; cp - result < size; cp++) {
 367                if (*cp == '\n')
 368                        cnt++;
 369        }
 370        if (result[size-1] != '\n')
 371                cnt++; /* incomplete line */
 372
 373        sline = xcalloc(cnt, sizeof(*sline));
 374        ep = result;
 375        sline[0].bol = result;
 376        for (lno = 0, cp = result; cp - result < size; cp++) {
 377                if (*cp == '\n') {
 378                        sline[lno].len = cp - sline[lno].bol;
 379                        sline[lno].flag = (1UL<<num_parent) - 1;
 380                        lno++;
 381                        if (lno < cnt)
 382                                sline[lno].bol = cp + 1;
 383                }
 384        }
 385        if (result[size-1] != '\n') {
 386                sline[cnt-1].len = size - (sline[cnt-1].bol - result);
 387                sline[cnt-1].flag = (1UL<<num_parent) - 1;
 388        }
 389
 390        for (i = 0; i < num_parent; i++)
 391                combine_diff(elem->parent_sha1[i], ourtmp, sline, cnt, i);
 392
 393        make_hunks(sline, cnt, num_parent);
 394
 395        dump_sline(sline, cnt, num_parent);
 396        unlink(ourtmp);
 397        free(result);
 398
 399        for (i = 0; i < cnt; i++) {
 400                if (sline[i].lost_head) {
 401                        struct lline *ll = sline[i].lost_head;
 402                        while (ll) {
 403                                struct lline *tmp = ll;
 404                                ll = ll->next;
 405                                free(tmp);
 406                        }
 407                }
 408        }
 409        free(sline);
 410}
 411
 412int diff_tree_combined_merge(const unsigned char *sha1,
 413                             const char *header, int show_empty_merge)
 414{
 415        struct commit *commit = lookup_commit(sha1);
 416        struct diff_options diffopts;
 417        struct commit_list *parents;
 418        struct path_list *p, *paths = NULL;
 419        int num_parent, i, num_paths;
 420
 421        diff_setup(&diffopts);
 422        diffopts.output_format = DIFF_FORMAT_NO_OUTPUT;
 423        diffopts.recursive = 1;
 424
 425        /* count parents */
 426        for (parents = commit->parents, num_parent = 0;
 427             parents;
 428             parents = parents->next, num_parent++)
 429                ; /* nothing */
 430
 431        /* find set of paths that everybody touches */
 432        for (parents = commit->parents, i = 0;
 433             parents;
 434             parents = parents->next, i++) {
 435                struct commit *parent = parents->item;
 436                diff_tree_sha1(parent->object.sha1, commit->object.sha1, "",
 437                               &diffopts);
 438                paths = intersect_paths(paths, i, num_parent);
 439                diff_flush(&diffopts);
 440        }
 441
 442        /* find out surviving paths */
 443        for (num_paths = 0, p = paths; p; p = p->next) {
 444                if (p->len)
 445                        num_paths++;
 446        }
 447        if (num_paths || show_empty_merge) {
 448                puts(header);
 449                for (p = paths; p; p = p->next) {
 450                        if (!p->len)
 451                                continue;
 452                        printf("diff --combined ");
 453                        if (quote_c_style(p->path, NULL, NULL, 0))
 454                                quote_c_style(p->path, NULL, stdout, 0);
 455                        else
 456                                printf("%s", p->path);
 457                        putchar('\n');
 458                        show_combined_diff(p, num_parent);
 459                }
 460        }
 461
 462        /* Clean things up */
 463        while (paths) {
 464                struct path_list *tmp = paths;
 465                paths = paths->next;
 466                free(tmp);
 467        }
 468        return 0;
 469}