Andrew's git - gitweb.git/blob

   1#include <ctype.h>
   2#include "cache.h"
   3#include "diff.h"
   4
   5static int silent = 0;
   6static int verbose_header = 0;
   7static int ignore_merges = 1;
   8static int recursive = 0;
   9static int read_stdin = 0;
  10static int line_termination = '\n';
  11static int generate_patch = 0;
  12static const char *header = NULL;
  13static const char *header_prefix = "";
  14
  15// What paths are we interested in?
  16static int nr_paths = 0;
  17static char **paths = NULL;
  18static int *pathlens = NULL;
  19
  20static int diff_tree_sha1(const unsigned char *old, const unsigned char *new, const char *base);
  21
  22static void update_tree_entry(void **bufp, unsigned long *sizep)
  23{
  24        void *buf = *bufp;
  25        unsigned long size = *sizep;
  26        int len = strlen(buf) + 1 + 20;
  27
  28        if (size < len)
  29                die("corrupt tree file");
  30        *bufp = buf + len;
  31        *sizep = size - len;
  32}
  33
  34static const unsigned char *extract(void *tree, unsigned long size, const char **pathp, unsigned int *modep)
  35{
  36        int len = strlen(tree)+1;
  37        const unsigned char *sha1 = tree + len;
  38        const char *path = strchr(tree, ' ');
  39
  40        if (!path || size < len + 20 || sscanf(tree, "%o", modep) != 1)
  41                die("corrupt tree file");
  42        *pathp = path+1;
  43        return sha1;
  44}
  45
  46static char *malloc_base(const char *base, const char *path, int pathlen)
  47{
  48        int baselen = strlen(base);
  49        char *newbase = xmalloc(baselen + pathlen + 2);
  50        memcpy(newbase, base, baselen);
  51        memcpy(newbase + baselen, path, pathlen);
  52        memcpy(newbase + baselen + pathlen, "/", 2);
  53        return newbase;
  54}
  55
  56static void show_file(const char *prefix, void *tree, unsigned long size, const char *base);
  57
  58/* A whole sub-tree went away or appeared */
  59static void show_tree(const char *prefix, void *tree, unsigned long size, const char *base)
  60{
  61        while (size) {
  62                show_file(prefix, tree, size, base);
  63                update_tree_entry(&tree, &size);
  64        }
  65}
  66
  67/* A file entry went away or appeared */
  68static void show_file(const char *prefix, void *tree, unsigned long size, const char *base)
  69{
  70        unsigned mode;
  71        const char *path;
  72        const unsigned char *sha1 = extract(tree, size, &path, &mode);
  73
  74        if (header) {
  75                printf("%s", header);
  76                header = NULL;
  77        }
  78
  79        if (silent)
  80                return;
  81
  82        if (recursive && S_ISDIR(mode)) {
  83                char type[20];
  84                unsigned long size;
  85                char *newbase = malloc_base(base, path, strlen(path));
  86                void *tree;
  87
  88                tree = read_sha1_file(sha1, type, &size);
  89                if (!tree || strcmp(type, "tree"))
  90                        die("corrupt tree sha %s", sha1_to_hex(sha1));
  91
  92                show_tree(prefix, tree, size, newbase);
  93                
  94                free(tree);
  95                free(newbase);
  96                return;
  97        }
  98
  99        if (generate_patch) {
 100                if (!S_ISDIR(mode))
 101                        diff_addremove(prefix[0], mode, sha1, base, path);
 102        }
 103        else
 104                printf("%s%06o\t%s\t%s\t%s%s%c", prefix, mode,
 105                       S_ISDIR(mode) ? "tree" : "blob",
 106                       sha1_to_hex(sha1), base, path,
 107                       line_termination);
 108}
 109
 110static int compare_tree_entry(void *tree1, unsigned long size1, void *tree2, unsigned long size2, const char *base)
 111{
 112        unsigned mode1, mode2;
 113        const char *path1, *path2;
 114        const unsigned char *sha1, *sha2;
 115        int cmp, pathlen1, pathlen2;
 116        char old_sha1_hex[50];
 117
 118        sha1 = extract(tree1, size1, &path1, &mode1);
 119        sha2 = extract(tree2, size2, &path2, &mode2);
 120
 121        pathlen1 = strlen(path1);
 122        pathlen2 = strlen(path2);
 123        cmp = cache_name_compare(path1, pathlen1, path2, pathlen2);
 124        if (cmp < 0) {
 125                show_file("-", tree1, size1, base);
 126                return -1;
 127        }
 128        if (cmp > 0) {
 129                show_file("+", tree2, size2, base);
 130                return 1;
 131        }
 132        if (!memcmp(sha1, sha2, 20) && mode1 == mode2)
 133                return 0;
 134
 135        /*
 136         * If the filemode has changed to/from a directory from/to a regular
 137         * file, we need to consider it a remove and an add.
 138         */
 139        if (S_ISDIR(mode1) != S_ISDIR(mode2)) {
 140                show_file("-", tree1, size1, base);
 141                show_file("+", tree2, size2, base);
 142                return 0;
 143        }
 144
 145        if (recursive && S_ISDIR(mode1)) {
 146                int retval;
 147                char *newbase = malloc_base(base, path1, pathlen1);
 148                retval = diff_tree_sha1(sha1, sha2, newbase);
 149                free(newbase);
 150                return retval;
 151        }
 152
 153        if (header) {
 154                printf("%s", header);
 155                header = NULL;
 156        }
 157        if (silent)
 158                return 0;
 159
 160        if (generate_patch) {
 161                if (!S_ISDIR(mode1))
 162                        diff_change(mode1, mode2, sha1, sha2, base, path1);
 163        }
 164        else {
 165                strcpy(old_sha1_hex, sha1_to_hex(sha1));
 166                printf("*%06o->%06o\t%s\t%s->%s\t%s%s%c", mode1, mode2,
 167                       S_ISDIR(mode1) ? "tree" : "blob",
 168                       old_sha1_hex, sha1_to_hex(sha2), base, path1,
 169                       line_termination);
 170        }
 171        return 0;
 172}
 173
 174static int interesting(void *tree, unsigned long size, const char *base)
 175{
 176        const char *path;
 177        unsigned mode;
 178        int i;
 179        int baselen, pathlen;
 180
 181        if (!nr_paths)
 182                return 1;
 183
 184        (void)extract(tree, size, &path, &mode);
 185
 186        pathlen = strlen(path);
 187        baselen = strlen(base);
 188
 189        for (i=0; i < nr_paths; i++) {
 190                const char *match = paths[i];
 191                int matchlen = pathlens[i];
 192
 193                if (baselen >= matchlen) {
 194                        /* If it doesn't match, move along... */
 195                        if (strncmp(base, match, matchlen))
 196                                continue;
 197
 198                        /* The base is a subdirectory of a path which was specified. */
 199                        return 1;
 200                }
 201
 202                /* Does the base match? */
 203                if (strncmp(base, match, baselen))
 204                        continue;
 205
 206                match += baselen;
 207                matchlen -= baselen;
 208
 209                if (pathlen > matchlen)
 210                        continue;
 211
 212                if (strncmp(path, match, pathlen))
 213                        continue;
 214
 215                return 1;
 216        }
 217        return 0; /* No matches */
 218}
 219
 220static int diff_tree(void *tree1, unsigned long size1, void *tree2, unsigned long size2, const char *base)
 221{
 222        while (size1 | size2) {
 223                if (nr_paths && size1 && !interesting(tree1, size1, base)) {
 224                        update_tree_entry(&tree1, &size1);
 225                        continue;
 226                }
 227                if (nr_paths && size2 && !interesting(tree2, size2, base)) {
 228                        update_tree_entry(&tree2, &size2);
 229                        continue;
 230                }
 231                if (!size1) {
 232                        show_file("+", tree2, size2, base);
 233                        update_tree_entry(&tree2, &size2);
 234                        continue;
 235                }
 236                if (!size2) {
 237                        show_file("-", tree1, size1, base);
 238                        update_tree_entry(&tree1, &size1);
 239                        continue;
 240                }
 241                switch (compare_tree_entry(tree1, size1, tree2, size2, base)) {
 242                case -1:
 243                        update_tree_entry(&tree1, &size1);
 244                        continue;
 245                case 0:
 246                        update_tree_entry(&tree1, &size1);
 247                        /* Fallthrough */
 248                case 1:
 249                        update_tree_entry(&tree2, &size2);
 250                        continue;
 251                }
 252                die("diff-tree: internal error");
 253        }
 254        return 0;
 255}
 256
 257static int diff_tree_sha1(const unsigned char *old, const unsigned char *new, const char *base)
 258{
 259        void *tree1, *tree2;
 260        unsigned long size1, size2;
 261        int retval;
 262
 263        tree1 = read_object_with_reference(old, "tree", &size1, 0);
 264        if (!tree1)
 265                die("unable to read source tree (%s)", sha1_to_hex(old));
 266        tree2 = read_object_with_reference(new, "tree", &size2, 0);
 267        if (!tree2)
 268                die("unable to read destination tree (%s)", sha1_to_hex(new));
 269        retval = diff_tree(tree1, size1, tree2, size2, base);
 270        free(tree1);
 271        free(tree2);
 272        return retval;
 273}
 274
 275static int get_one_line(const char *msg, unsigned long len)
 276{
 277        int ret = 0;
 278
 279        while (len--) {
 280                ret++;
 281                if (*msg++ == '\n')
 282                        break;
 283        }
 284        return ret;
 285}
 286
 287static char *generate_header(const char *commit, const char *parent, const char *msg, unsigned long len)
 288{
 289        static char this_header[1000];
 290        int offset;
 291
 292        offset = sprintf(this_header, "%s%s (from %s)\n", header_prefix, commit, parent);
 293        if (verbose_header) {
 294                int hdr = 1;
 295
 296                for (;;) {
 297                        const char *line = msg;
 298                        int linelen = get_one_line(msg, len);
 299
 300                        if (!linelen)
 301                                break;
 302                        if (offset + linelen + 10 > sizeof(this_header))
 303                                break;
 304
 305                        msg += linelen;
 306                        len -= linelen;
 307                        if (linelen == 1)
 308                                hdr = 0;
 309                        if (hdr)
 310                                continue;
 311                        memset(this_header + offset, ' ', 4);
 312                        memcpy(this_header + offset + 4, line, linelen);
 313                        offset += linelen + 4;
 314                }
 315                this_header[offset++] = '\n';
 316                this_header[offset] = 0;
 317        }
 318
 319        return this_header;
 320}
 321
 322static int diff_tree_stdin(char *line)
 323{
 324        int len = strlen(line);
 325        unsigned char commit[20], parent[20];
 326        unsigned long size, offset;
 327        static char this_header[1000];
 328        char *buf;
 329
 330        if (!len || line[len-1] != '\n')
 331                return -1;
 332        line[len-1] = 0;
 333        if (get_sha1_hex(line, commit))
 334                return -1;
 335        if (isspace(line[40]) && !get_sha1_hex(line+41, parent)) {
 336                line[40] = 0;
 337                line[81] = 0;
 338                sprintf(this_header, "%s (from %s)\n", line, line+41);
 339                header = this_header;
 340                return diff_tree_sha1(parent, commit, "");
 341        }
 342        buf = read_object_with_reference(commit, "commit", &size, NULL);
 343        if (!buf)
 344                return -1;
 345
 346        /* More than one parent? */
 347        if (ignore_merges) {
 348                if (!memcmp(buf + 46 + 48, "parent ", 7))
 349                        return 0;
 350        }
 351
 352        line[40] = 0;
 353        offset = 46;
 354        while (offset + 48 < size && !memcmp(buf + offset, "parent ", 7)) {
 355                if (get_sha1_hex(buf + offset + 7, parent))
 356                        return -1;
 357                header = generate_header(line, sha1_to_hex(parent), buf, size);
 358                diff_tree_sha1(parent, commit, "");
 359                if (!header && verbose_header)
 360                        header_prefix = "\ndiff-tree ";
 361                offset += 48;
 362        }
 363        return -1;
 364}
 365
 366static char *diff_tree_usage =
 367"diff-tree [-p] [-r] [-z] [--stdin] [-m] [-s] [-v] <tree sha1> <tree sha1>";
 368
 369int main(int argc, char **argv)
 370{
 371        char line[1000];
 372        unsigned char old[20], new[20];
 373
 374        for (;;) {
 375                char *arg;
 376
 377                argv++;
 378                argc--;
 379                arg = *argv;
 380                if (!arg || *arg != '-')
 381                        break;
 382
 383                if (!strcmp(arg, "-")) {
 384                        argv++;
 385                        argc--;
 386                        break;
 387                }
 388                if (!strcmp(arg, "-r")) {
 389                        recursive = 1;
 390                        continue;
 391                }
 392                if (!strcmp(arg, "-p")) {
 393                        recursive = generate_patch = 1;
 394                        continue;
 395                }
 396                if (!strcmp(arg, "-z")) {
 397                        line_termination = '\0';
 398                        continue;
 399                }
 400                if (!strcmp(arg, "-m")) {
 401                        ignore_merges = 0;
 402                        continue;
 403                }
 404                if (!strcmp(arg, "-s")) {
 405                        silent = 1;
 406                        continue;
 407                }
 408                if (!strcmp(arg, "-v")) {
 409                        verbose_header = 1;
 410                        header_prefix = "diff-tree ";
 411                        continue;
 412                }
 413                if (!strcmp(arg, "--stdin")) {
 414                        read_stdin = 1;
 415                        continue;
 416                }
 417                usage(diff_tree_usage);
 418        }
 419
 420        if (!read_stdin) {
 421                if (argc < 2 || get_sha1(argv[0], old) || get_sha1(argv[1], new))
 422                        usage(diff_tree_usage);
 423                argv += 2;
 424                argc -= 2;
 425        }
 426
 427        if (argc > 0) {
 428                int i;
 429
 430                paths = argv;
 431                nr_paths = argc;
 432                pathlens = xmalloc(nr_paths * sizeof(int));
 433                for (i=0; i<nr_paths; i++)
 434                        pathlens[i] = strlen(paths[i]);
 435        }
 436
 437        if (!read_stdin)
 438                return diff_tree_sha1(old, new, "");
 439
 440        while (fgets(line, sizeof(line), stdin))
 441                diff_tree_stdin(line);
 442
 443        return 0;
 444}