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
   9 static char *def = NULL;
  10 static int no_revs = 0;
  11 static int single_rev = 0;
  12 static int revs_only = 0;
  13 static int do_rev_argument = 1;
  14 static int output_revs = 0;
  15
  16 static int get_extended_sha1(char *name, unsigned char *sha1);
  17
  18 /*
  19  * Some arguments are relevant "revision" arguments,
  20  * others are about output format or other details.
  21  * This sorts it all out.
  22  */
  23 static int is_rev_argument(const char *arg)
  24 {
  25         static const char *rev_args[] = {
  26                 "--max-count=",
  27                 "--max-age=",
  28                 "--min-age=",
  29                 "--merge-order",
  30                 NULL
  31         };
  32         const char **p = rev_args;
  33
  34         for (;;) {
  35                 const char *str = *p++;
  36                 int len;
  37                 if (!str)
  38                         return 0;
  39                 len = strlen(str);
  40                 if (!strncmp(arg, str, len))
  41                         return 1;
  42         }
  43 }
  44
  45 static void show_rev(unsigned char *sha1)
  46 {
  47         if (no_revs)
  48                 return;
  49         output_revs++;
  50         puts(sha1_to_hex(sha1));
  51 }
  52
  53 static void show_antirev(unsigned char *sha1)
  54 {
  55         if (no_revs)
  56                 return;
  57         output_revs++;
  58         printf("^%s\n", sha1_to_hex(sha1));
  59 }
  60
  61 static void show_rev_arg(char *rev)
  62 {
  63         if (no_revs)
  64                 return;
  65         puts(rev);
  66 }
  67
  68 static void show_norev(char *norev)
  69 {
  70         if (revs_only)
  71                 return;
  72         puts(norev);
  73 }
  74
  75 static void show_arg(char *arg)
  76 {
  77         if (do_rev_argument && is_rev_argument(arg))
  78                 show_rev_arg(arg);
  79         else
  80                 show_norev(arg);
  81 }
  82
  83 static int get_parent(char *name, unsigned char *result, int idx)
  84 {
  85         unsigned char sha1[20];
  86         int ret = get_extended_sha1(name, sha1);
  87         struct commit *commit;
  88         struct commit_list *p;
  89
  90         if (ret)
  91                 return ret;
  92         commit = lookup_commit_reference(sha1);
  93         if (!commit)
  94                 return -1;
  95         if (parse_commit(commit))
  96                 return -1;
  97         p = commit->parents;
  98         while (p) {
  99                 if (!--idx) {
 100                         memcpy(result, p->item->object.sha1, 20);
 101                         return 0;
 102                 }
 103                 p = p->next;
 104         }
 105         return -1;
 106 }
 107
 108 /*
 109  * This is like "get_sha1()", except it allows "sha1 expressions",
 110  * notably "xyz^" for "parent of xyz"
 111  */
 112 static int get_extended_sha1(char *name, unsigned char *sha1)
 113 {
 114         int parent;
 115         int len = strlen(name);
 116
 117         parent = 1;
 118         if (len > 2 && name[len-1] >= '1' && name[len-1] <= '9') {
 119                 parent = name[len-1] - '0';
 120                 len--;
 121         }
 122         if (len > 1 && name[len-1] == '^') {
 123                 int ret;
 124                 name[len-1] = 0;
 125                 ret = get_parent(name, sha1, parent);
 126                 name[len-1] = '^';
 127                 if (!ret)
 128                         return 0;
 129         }
 130         return get_sha1(name, sha1);
 131 }
 132
 133 static void show_default(void)
 134 {
 135         char *s = def;
 136
 137         if (s) {
 138                 unsigned char sha1[20];
 139
 140                 def = NULL;
 141                 if (!get_extended_sha1(s, sha1)) {
 142                         show_rev(sha1);
 143                         return;
 144                 }
 145                 show_arg(s);
 146         }
 147 }
 148
 149 int main(int argc, char **argv)
 150 {
 151         int i, as_is = 0;
 152         unsigned char sha1[20];
 153
 154         for (i = 1; i < argc; i++) {
 155                 char *arg = argv[i];
 156                 char *dotdot;
 157
 158                 if (as_is) {
 159                         show_norev(arg);
 160                         continue;
 161                 }
 162                 if (*arg == '-') {
 163                         if (!strcmp(arg, "--")) {
 164                                 show_default();
 165                                 if (revs_only)
 166                                         break;
 167                                 as_is = 1;
 168                         }
 169                         if (!strcmp(arg, "--default")) {
 170                                 def = argv[i+1];
 171                                 i++;
 172                                 continue;
 173                         }
 174                         if (!strcmp(arg, "--revs-only")) {
 175                                 revs_only = 1;
 176                                 continue;
 177                         }
 178                         if (!strcmp(arg, "--no-revs")) {
 179                                 no_revs = 1;
 180                                 continue;
 181                         }
 182                         if (!strcmp(arg, "--verify")) {
 183                                 revs_only = 1;
 184                                 do_rev_argument = 0;
 185                                 single_rev = 1;
 186                                 continue;
 187                         }
 188                         show_arg(arg);
 189                         continue;
 190                 }
 191                 dotdot = strstr(arg, "..");
 192                 if (dotdot) {
 193                         unsigned char end[20];
 194                         char *n = dotdot+2;
 195                         *dotdot = 0;
 196                         if (!get_extended_sha1(arg, sha1)) {
 197                                 if (!*n)
 198                                         n = "HEAD";
 199                                 if (!get_extended_sha1(n, end)) {
 200                                         if (no_revs)
 201                                                 continue;
 202                                         def = NULL;
 203                                         show_rev(end);
 204                                         show_antirev(sha1);
 205                                         continue;
 206                                 }
 207                         }
 208                         *dotdot = '.';
 209                 }
 210                 if (!get_extended_sha1(arg, sha1)) {
 211                         if (no_revs)
 212                                 continue;
 213                         def = NULL;
 214                         show_rev(sha1);
 215                         continue;
 216                 }
 217                 if (*arg == '^' && !get_extended_sha1(arg+1, sha1)) {
 218                         if (no_revs)
 219                                 continue;
 220                         def = NULL;
 221                         show_antirev(sha1);
 222                         continue;
 223                 }
 224                 show_default();
 225                 show_norev(arg);
 226         }
 227         show_default();
 228         if (single_rev && output_revs != 1) {
 229                 fprintf(stderr, "Needed a single revision\n");
 230                 exit(1);
 231         }
 232         return 0;
 233 }