builtin/patch-id.c

   1 #include "cache.h"
   2 #include "builtin.h"
   3 #include "config.h"
   4 #include "diff.h"
   5
   6 static void flush_current_id(int patchlen, struct object_id *id, struct object_id *result)
   7 {
   8         if (patchlen)
   9                 printf("%s %s\n", oid_to_hex(result), oid_to_hex(id));
  10 }
  11
  12 static int remove_space(char *line)
  13 {
  14         char *src = line;
  15         char *dst = line;
  16         unsigned char c;
  17
  18         while ((c = *src++) != '\0') {
  19                 if (!isspace(c))
  20                         *dst++ = c;
  21         }
  22         return dst - line;
  23 }
  24
  25 static int scan_hunk_header(const char *p, int *p_before, int *p_after)
  26 {
  27         static const char digits[] = "0123456789";
  28         const char *q, *r;
  29         int n;
  30
  31         q = p + 4;
  32         n = strspn(q, digits);
  33         if (q[n] == ',') {
  34                 q += n + 1;
  35                 n = strspn(q, digits);
  36         }
  37         if (n == 0 || q[n] != ' ' || q[n+1] != '+')
  38                 return 0;
  39
  40         r = q + n + 2;
  41         n = strspn(r, digits);
  42         if (r[n] == ',') {
  43                 r += n + 1;
  44                 n = strspn(r, digits);
  45         }
  46         if (n == 0)
  47                 return 0;
  48
  49         *p_before = atoi(q);
  50         *p_after = atoi(r);
  51         return 1;
  52 }
  53
  54 static int get_one_patchid(struct object_id *next_oid, struct object_id *result,
  55                            struct strbuf *line_buf, int stable)
  56 {
  57         int patchlen = 0, found_next = 0;
  58         int before = -1, after = -1;
  59         git_hash_ctx ctx;
  60
  61         the_hash_algo->init_fn(&ctx);
  62         oidclr(result);
  63
  64         while (strbuf_getwholeline(line_buf, stdin, '\n') != EOF) {
  65                 char *line = line_buf->buf;
  66                 const char *p = line;
  67                 int len;
  68
  69                 if (!skip_prefix(line, "diff-tree ", &p) &&
  70                     !skip_prefix(line, "commit ", &p) &&
  71                     !skip_prefix(line, "From ", &p) &&
  72                     starts_with(line, "\\ ") && 12 < strlen(line))
  73                         continue;
  74
  75                 if (!get_oid_hex(p, next_oid)) {
  76                         found_next = 1;
  77                         break;
  78                 }
  79
  80                 /* Ignore commit comments */
  81                 if (!patchlen && !starts_with(line, "diff "))
  82                         continue;
  83
  84                 /* Parsing diff header?  */
  85                 if (before == -1) {
  86                         if (starts_with(line, "index "))
  87                                 continue;
  88                         else if (starts_with(line, "--- "))
  89                                 before = after = 1;
  90                         else if (!isalpha(line[0]))
  91                                 break;
  92                 }
  93
  94                 /* Looking for a valid hunk header?  */
  95                 if (before == 0 && after == 0) {
  96                         if (starts_with(line, "@@ -")) {
  97                                 /* Parse next hunk, but ignore line numbers.  */
  98                                 scan_hunk_header(line, &before, &after);
  99                                 continue;
 100                         }
 101
 102                         /* Split at the end of the patch.  */
 103                         if (!starts_with(line, "diff "))
 104                                 break;
 105
 106                         /* Else we're parsing another header.  */
 107                         if (stable)
 108                                 flush_one_hunk(result, &ctx);
 109                         before = after = -1;
 110                 }
 111
 112                 /* If we get here, we're inside a hunk.  */
 113                 if (line[0] == '-' || line[0] == ' ')
 114                         before--;
 115                 if (line[0] == '+' || line[0] == ' ')
 116                         after--;
 117
 118                 /* Compute the sha without whitespace */
 119                 len = remove_space(line);
 120                 patchlen += len;
 121                 the_hash_algo->update_fn(&ctx, line, len);
 122         }
 123
 124         if (!found_next)
 125                 oidclr(next_oid);
 126
 127         flush_one_hunk(result, &ctx);
 128
 129         return patchlen;
 130 }
 131
 132 static void generate_id_list(int stable)
 133 {
 134         struct object_id oid, n, result;
 135         int patchlen;
 136         struct strbuf line_buf = STRBUF_INIT;
 137
 138         oidclr(&oid);
 139         while (!feof(stdin)) {
 140                 patchlen = get_one_patchid(&n, &result, &line_buf, stable);
 141                 flush_current_id(patchlen, &oid, &result);
 142                 oidcpy(&oid, &n);
 143         }
 144         strbuf_release(&line_buf);
 145 }
 146
 147 static const char patch_id_usage[] = "git patch-id [--stable | --unstable]";
 148
 149 static int git_patch_id_config(const char *var, const char *value, void *cb)
 150 {
 151         int *stable = cb;
 152
 153         if (!strcmp(var, "patchid.stable")) {
 154                 *stable = git_config_bool(var, value);
 155                 return 0;
 156         }
 157
 158         return git_default_config(var, value, cb);
 159 }
 160
 161 int cmd_patch_id(int argc, const char **argv, const char *prefix)
 162 {
 163         int stable = -1;
 164
 165         git_config(git_patch_id_config, &stable);
 166
 167         /* If nothing is set, default to unstable. */
 168         if (stable < 0)
 169                 stable = 0;
 170
 171         if (argc == 2 && !strcmp(argv[1], "--stable"))
 172                 stable = 1;
 173         else if (argc == 2 && !strcmp(argv[1], "--unstable"))
 174                 stable = 0;
 175         else if (argc != 1)
 176                 usage(patch_id_usage);
 177
 178         generate_id_list(stable);
 179         return 0;
 180 }