Andrew's git - gitweb.git/blob

95da465f14d2dbe8cd923bf64746e1f0bcab6407
   1/*
   2 * rev-parse.c
   3 *
   4 * Copyright (C) Linus Torvalds, 2005
   5 */
   6#include "cache.h"
   7#include "commit.h"
   8#include "refs.h"
   9
  10static char *def = NULL;
  11static int no_revs = 0;
  12static int single_rev = 0;
  13static int revs_only = 0;
  14static int do_rev_argument = 1;
  15static int output_revs = 0;
  16
  17#define NORMAL 0
  18#define REVERSED 1
  19static int show_type = NORMAL;
  20
  21static int get_extended_sha1(char *name, unsigned char *sha1);
  22
  23/*
  24 * Some arguments are relevant "revision" arguments,
  25 * others are about output format or other details.
  26 * This sorts it all out.
  27 */
  28static int is_rev_argument(const char *arg)
  29{
  30        static const char *rev_args[] = {
  31                "--max-count=",
  32                "--max-age=",
  33                "--min-age=",
  34                "--merge-order",
  35                NULL
  36        };
  37        const char **p = rev_args;
  38
  39        for (;;) {
  40                const char *str = *p++;
  41                int len;
  42                if (!str)
  43                        return 0;
  44                len = strlen(str);
  45                if (!strncmp(arg, str, len))
  46                        return 1;
  47        }
  48}
  49
  50static void show_rev(int type, const unsigned char *sha1)
  51{
  52        if (no_revs)
  53                return;
  54        output_revs++;
  55        printf("%s%s\n", type == show_type ? "" : "^", sha1_to_hex(sha1));
  56}
  57
  58static void show_rev_arg(char *rev)
  59{
  60        if (no_revs)
  61                return;
  62        puts(rev);
  63}
  64
  65static void show_norev(char *norev)
  66{
  67        if (revs_only)
  68                return;
  69        puts(norev);
  70}
  71
  72static void show_arg(char *arg)
  73{
  74        if (do_rev_argument && is_rev_argument(arg))
  75                show_rev_arg(arg);
  76        else
  77                show_norev(arg);
  78}
  79
  80static int get_parent(char *name, unsigned char *result, int idx)
  81{
  82        unsigned char sha1[20];
  83        int ret = get_extended_sha1(name, sha1);
  84        struct commit *commit;
  85        struct commit_list *p;
  86
  87        if (ret)
  88                return ret;
  89        commit = lookup_commit_reference(sha1);
  90        if (!commit)
  91                return -1;
  92        if (parse_commit(commit))
  93                return -1;
  94        p = commit->parents;
  95        while (p) {
  96                if (!--idx) {
  97                        memcpy(result, p->item->object.sha1, 20);
  98                        return 0;
  99                }
 100                p = p->next;
 101        }
 102        return -1;
 103}
 104
 105static int find_short_object_filename(int len, const char *name, unsigned char *sha1)
 106{
 107        static char dirname[PATH_MAX];
 108        char hex[40];
 109        DIR *dir;
 110        int found;
 111
 112        snprintf(dirname, sizeof(dirname), "%s/%.2s", get_object_directory(), name);
 113        dir = opendir(dirname);
 114        sprintf(hex, "%.2s", name);
 115        found = 0;
 116        if (dir) {
 117                struct dirent *de;
 118                while ((de = readdir(dir)) != NULL) {
 119                        if (strlen(de->d_name) != 38)
 120                                continue;
 121                        if (memcmp(de->d_name, name + 2, len-2))
 122                                continue;
 123                        memcpy(hex + 2, de->d_name, 38);
 124                        if (++found > 1)
 125                                break;
 126                }
 127                closedir(dir);
 128        }
 129        if (found == 1)
 130                return get_sha1_hex(hex, sha1) == 0;
 131        return 0;
 132}
 133
 134static int find_short_packed_object(int len, const unsigned char *match, unsigned char *sha1)
 135{
 136        return 0;
 137}
 138
 139static int get_short_sha1(char *name, unsigned char *sha1)
 140{
 141        int i;
 142        char canonical[40];
 143        unsigned char res[20];
 144
 145        memset(res, 0, 20);
 146        memset(canonical, 'x', 40);
 147        for (i = 0;;i++) {
 148                unsigned char c = name[i];
 149                unsigned char val;
 150                if (!c || i > 40)
 151                        break;
 152                if (c >= '0' && c <= '9')
 153                        val = c - '0';
 154                else if (c >= 'a' && c <= 'f')
 155                        val = c - 'a' + 10;
 156                else if (c >= 'A' && c <='F') {
 157                        val = c - 'A' + 10;
 158                        c -= 'A' - 'a';
 159                }
 160                else
 161                        return -1;
 162                canonical[i] = c;
 163                if (!(i & 1))
 164                        val <<= 4;
 165                res[i >> 1] |= val;
 166        }
 167        if (i < 4)
 168                return -1;
 169        if (find_short_object_filename(i, canonical, sha1))
 170                return 0;
 171        if (find_short_packed_object(i, res, sha1))
 172                return 0;
 173        return -1;
 174}
 175
 176/*
 177 * This is like "get_sha1()", except it allows "sha1 expressions",
 178 * notably "xyz^" for "parent of xyz"
 179 */
 180static int get_extended_sha1(char *name, unsigned char *sha1)
 181{
 182        int parent, ret;
 183        int len = strlen(name);
 184
 185        parent = 1;
 186        if (len > 2 && name[len-1] >= '1' && name[len-1] <= '9') {
 187                parent = name[len-1] - '0';
 188                len--;
 189        }
 190        if (len > 1 && name[len-1] == '^') {
 191                name[len-1] = 0;
 192                ret = get_parent(name, sha1, parent);
 193                name[len-1] = '^';
 194                if (!ret)
 195                        return 0;
 196        }
 197        ret = get_sha1(name, sha1);
 198        if (!ret)
 199                return 0;
 200        return get_short_sha1(name, sha1);
 201}
 202
 203static void show_default(void)
 204{
 205        char *s = def;
 206
 207        if (s) {
 208                unsigned char sha1[20];
 209
 210                def = NULL;
 211                if (!get_extended_sha1(s, sha1)) {
 212                        show_rev(NORMAL, sha1);
 213                        return;
 214                }
 215                show_arg(s);
 216        }
 217}
 218
 219static int show_reference(const char *refname, const unsigned char *sha1)
 220{
 221        show_rev(NORMAL, sha1);
 222        return 0;
 223}
 224
 225int main(int argc, char **argv)
 226{
 227        int i, as_is = 0;
 228        unsigned char sha1[20];
 229
 230        for (i = 1; i < argc; i++) {
 231                char *arg = argv[i];
 232                char *dotdot;
 233        
 234                if (as_is) {
 235                        show_norev(arg);
 236                        continue;
 237                }
 238                if (*arg == '-') {
 239                        if (!strcmp(arg, "--")) {
 240                                show_default();
 241                                if (revs_only)
 242                                        break;
 243                                as_is = 1;
 244                        }
 245                        if (!strcmp(arg, "--default")) {
 246                                def = argv[i+1];
 247                                i++;
 248                                continue;
 249                        }
 250                        if (!strcmp(arg, "--revs-only")) {
 251                                revs_only = 1;
 252                                continue;
 253                        }
 254                        if (!strcmp(arg, "--no-revs")) {
 255                                no_revs = 1;
 256                                continue;
 257                        }
 258                        if (!strcmp(arg, "--verify")) {
 259                                revs_only = 1;
 260                                do_rev_argument = 0;
 261                                single_rev = 1;
 262                                continue;
 263                        }
 264                        if (!strcmp(arg, "--not")) {
 265                                show_type ^= REVERSED;
 266                                continue;
 267                        }
 268                        if (!strcmp(arg, "--all")) {
 269                                for_each_ref(show_reference);
 270                                continue;
 271                        }
 272                        show_arg(arg);
 273                        continue;
 274                }
 275                dotdot = strstr(arg, "..");
 276                if (dotdot) {
 277                        unsigned char end[20];
 278                        char *n = dotdot+2;
 279                        *dotdot = 0;
 280                        if (!get_extended_sha1(arg, sha1)) {
 281                                if (!*n)
 282                                        n = "HEAD";
 283                                if (!get_extended_sha1(n, end)) {
 284                                        if (no_revs)
 285                                                continue;
 286                                        def = NULL;
 287                                        show_rev(NORMAL, end);
 288                                        show_rev(REVERSED, sha1);
 289                                        continue;
 290                                }
 291                        }
 292                        *dotdot = '.';
 293                }
 294                if (!get_extended_sha1(arg, sha1)) {
 295                        if (no_revs)
 296                                continue;
 297                        def = NULL;
 298                        show_rev(NORMAL, sha1);
 299                        continue;
 300                }
 301                if (*arg == '^' && !get_extended_sha1(arg+1, sha1)) {
 302                        if (no_revs)
 303                                continue;
 304                        def = NULL;
 305                        show_rev(REVERSED, sha1);
 306                        continue;
 307                }
 308                show_default();
 309                show_norev(arg);
 310        }
 311        show_default();
 312        if (single_rev && output_revs != 1) {
 313                fprintf(stderr, "Needed a single revision\n");
 314                exit(1);
 315        }
 316        return 0;
 317}