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 /*
 106  * This is like "get_sha1()", except it allows "sha1 expressions",
 107  * notably "xyz^" for "parent of xyz"
 108  */
 109 static int get_extended_sha1(char *name, unsigned char *sha1)
 110 {
 111         int parent;
 112         int len = strlen(name);
 113
 114         parent = 1;
 115         if (len > 2 && name[len-1] >= '1' && name[len-1] <= '9') {
 116                 parent = name[len-1] - '0';
 117                 len--;
 118         }
 119         if (len > 1 && name[len-1] == '^') {
 120                 int ret;
 121                 name[len-1] = 0;
 122                 ret = get_parent(name, sha1, parent);
 123                 name[len-1] = '^';
 124                 if (!ret)
 125                         return 0;
 126         }
 127         return get_sha1(name, sha1);
 128 }
 129
 130 static void show_default(void)
 131 {
 132         char *s = def;
 133
 134         if (s) {
 135                 unsigned char sha1[20];
 136
 137                 def = NULL;
 138                 if (!get_extended_sha1(s, sha1)) {
 139                         show_rev(NORMAL, sha1);
 140                         return;
 141                 }
 142                 show_arg(s);
 143         }
 144 }
 145
 146 static int show_reference(const char *refname, const unsigned char *sha1)
 147 {
 148         show_rev(NORMAL, sha1);
 149         return 0;
 150 }
 151
 152 int main(int argc, char **argv)
 153 {
 154         int i, as_is = 0;
 155         unsigned char sha1[20];
 156
 157         for (i = 1; i < argc; i++) {
 158                 char *arg = argv[i];
 159                 char *dotdot;
 160
 161                 if (as_is) {
 162                         show_norev(arg);
 163                         continue;
 164                 }
 165                 if (*arg == '-') {
 166                         if (!strcmp(arg, "--")) {
 167                                 show_default();
 168                                 if (revs_only)
 169                                         break;
 170                                 as_is = 1;
 171                         }
 172                         if (!strcmp(arg, "--default")) {
 173                                 def = argv[i+1];
 174                                 i++;
 175                                 continue;
 176                         }
 177                         if (!strcmp(arg, "--revs-only")) {
 178                                 revs_only = 1;
 179                                 continue;
 180                         }
 181                         if (!strcmp(arg, "--no-revs")) {
 182                                 no_revs = 1;
 183                                 continue;
 184                         }
 185                         if (!strcmp(arg, "--verify")) {
 186                                 revs_only = 1;
 187                                 do_rev_argument = 0;
 188                                 single_rev = 1;
 189                                 continue;
 190                         }
 191                         if (!strcmp(arg, "--not")) {
 192                                 show_type ^= REVERSED;
 193                                 continue;
 194                         }
 195                         if (!strcmp(arg, "--all")) {
 196                                 for_each_ref(show_reference);
 197                                 continue;
 198                         }
 199                         show_arg(arg);
 200                         continue;
 201                 }
 202                 dotdot = strstr(arg, "..");
 203                 if (dotdot) {
 204                         unsigned char end[20];
 205                         char *n = dotdot+2;
 206                         *dotdot = 0;
 207                         if (!get_extended_sha1(arg, sha1)) {
 208                                 if (!*n)
 209                                         n = "HEAD";
 210                                 if (!get_extended_sha1(n, end)) {
 211                                         if (no_revs)
 212                                                 continue;
 213                                         def = NULL;
 214                                         show_rev(NORMAL, end);
 215                                         show_rev(REVERSED, sha1);
 216                                         continue;
 217                                 }
 218                         }
 219                         *dotdot = '.';
 220                 }
 221                 if (!get_extended_sha1(arg, sha1)) {
 222                         if (no_revs)
 223                                 continue;
 224                         def = NULL;
 225                         show_rev(NORMAL, sha1);
 226                         continue;
 227                 }
 228                 if (*arg == '^' && !get_extended_sha1(arg+1, sha1)) {
 229                         if (no_revs)
 230                                 continue;
 231                         def = NULL;
 232                         show_rev(REVERSED, sha1);
 233                         continue;
 234                 }
 235                 show_default();
 236                 show_norev(arg);
 237         }
 238         show_default();
 239         if (single_rev && output_revs != 1) {
 240                 fprintf(stderr, "Needed a single revision\n");
 241                 exit(1);
 242         }
 243         return 0;
 244 }