rev-parse.c

   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
  10 static char *def = NULL;
  11 static int no_revs = 0;
  12 static int single_rev = 0;
  13 static int revs_only = 0;
  14 static int do_rev_argument = 1;
  15 static int output_revs = 0;
  16
  17 #define NORMAL 0
  18 #define REVERSED 1
  19 static int show_type = NORMAL;
  20
  21 static 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  */
  28 static 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
  50 static 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
  58 static void show_rev_arg(char *rev)
  59 {
  60         if (no_revs)
  61                 return;
  62         puts(rev);
  63 }
  64
  65 static void show_norev(char *norev)
  66 {
  67         if (revs_only)
  68                 return;
  69         puts(norev);
  70 }
  71
  72 static 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
  80 static 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
 105 static 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
 134 static int find_short_packed_object(int len, const unsigned char *match, unsigned char *sha1)
 135 {
 136         return 0;
 137 }
 138
 139 static 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  */
 180 static 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
 203 static 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
 219 static int show_reference(const char *refname, const unsigned char *sha1)
 220 {
 221         show_rev(NORMAL, sha1);
 222         return 0;
 223 }
 224
 225 int 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 }