builtin/patch-id.c

   1 #include "builtin.h"
   2
   3 static void flush_current_id(int patchlen, struct object_id *id, struct object_id *result)
   4 {
   5         char name[50];
   6
   7         if (!patchlen)
   8                 return;
   9
  10         memcpy(name, oid_to_hex(id), GIT_SHA1_HEXSZ + 1);
  11         printf("%s %s\n", oid_to_hex(result), name);
  12 }
  13
  14 static int remove_space(char *line)
  15 {
  16         char *src = line;
  17         char *dst = line;
  18         unsigned char c;
  19
  20         while ((c = *src++) != '\0') {
  21                 if (!isspace(c))
  22                         *dst++ = c;
  23         }
  24         return dst - line;
  25 }
  26
  27 static int scan_hunk_header(const char *p, int *p_before, int *p_after)
  28 {
  29         static const char digits[] = "0123456789";
  30         const char *q, *r;
  31         int n;
  32
  33         q = p + 4;
  34         n = strspn(q, digits);
  35         if (q[n] == ',') {
  36                 q += n + 1;
  37                 n = strspn(q, digits);
  38         }
  39         if (n == 0 || q[n] != ' ' || q[n+1] != '+')
  40                 return 0;
  41
  42         r = q + n + 2;
  43         n = strspn(r, digits);
  44         if (r[n] == ',') {
  45                 r += n + 1;
  46                 n = strspn(r, digits);
  47         }
  48         if (n == 0)
  49                 return 0;
  50
  51         *p_before = atoi(q);
  52         *p_after = atoi(r);
  53         return 1;
  54 }
  55
  56 static void flush_one_hunk(struct object_id *result, git_SHA_CTX *ctx)
  57 {
  58         unsigned char hash[GIT_SHA1_RAWSZ];
  59         unsigned short carry = 0;
  60         int i;
  61
  62         git_SHA1_Final(hash, ctx);
  63         git_SHA1_Init(ctx);
  64         /* 20-byte sum, with carry */
  65         for (i = 0; i < GIT_SHA1_RAWSZ; ++i) {
  66                 carry += result->hash[i] + hash[i];
  67                 result->hash[i] = carry;
  68                 carry >>= 8;
  69         }
  70 }
  71
  72 static int get_one_patchid(struct object_id *next_oid, struct object_id *result,
  73                            struct strbuf *line_buf, int stable)
  74 {
  75         int patchlen = 0, found_next = 0;
  76         int before = -1, after = -1;
  77         git_SHA_CTX ctx;
  78
  79         git_SHA1_Init(&ctx);
  80         oidclr(result);
  81
  82         while (strbuf_getwholeline(line_buf, stdin, '\n') != EOF) {
  83                 char *line = line_buf->buf;
  84                 const char *p = line;
  85                 int len;
  86
  87                 if (!skip_prefix(line, "diff-tree ", &p) &&
  88                     !skip_prefix(line, "commit ", &p) &&
  89                     !skip_prefix(line, "From ", &p) &&
  90                     starts_with(line, "\\ ") && 12 < strlen(line))
  91                         continue;
  92
  93                 if (!get_oid_hex(p, next_oid)) {
  94                         found_next = 1;
  95                         break;
  96                 }
  97
  98                 /* Ignore commit comments */
  99                 if (!patchlen && !starts_with(line, "diff "))
 100                         continue;
 101
 102                 /* Parsing diff header?  */
 103                 if (before == -1) {
 104                         if (starts_with(line, "index "))
 105                                 continue;
 106                         else if (starts_with(line, "--- "))
 107                                 before = after = 1;
 108                         else if (!isalpha(line[0]))
 109                                 break;
 110                 }
 111
 112                 /* Looking for a valid hunk header?  */
 113                 if (before == 0 && after == 0) {
 114                         if (starts_with(line, "@@ -")) {
 115                                 /* Parse next hunk, but ignore line numbers.  */
 116                                 scan_hunk_header(line, &before, &after);
 117                                 continue;
 118                         }
 119
 120                         /* Split at the end of the patch.  */
 121                         if (!starts_with(line, "diff "))
 122                                 break;
 123
 124                         /* Else we're parsing another header.  */
 125                         if (stable)
 126                                 flush_one_hunk(result, &ctx);
 127                         before = after = -1;
 128                 }
 129
 130                 /* If we get here, we're inside a hunk.  */
 131                 if (line[0] == '-' || line[0] == ' ')
 132                         before--;
 133                 if (line[0] == '+' || line[0] == ' ')
 134                         after--;
 135
 136                 /* Compute the sha without whitespace */
 137                 len = remove_space(line);
 138                 patchlen += len;
 139                 git_SHA1_Update(&ctx, line, len);
 140         }
 141
 142         if (!found_next)
 143                 oidclr(next_oid);
 144
 145         flush_one_hunk(result, &ctx);
 146
 147         return patchlen;
 148 }
 149
 150 static void generate_id_list(int stable)
 151 {
 152         struct object_id oid, n, result;
 153         int patchlen;
 154         struct strbuf line_buf = STRBUF_INIT;
 155
 156         oidclr(&oid);
 157         while (!feof(stdin)) {
 158                 patchlen = get_one_patchid(&n, &result, &line_buf, stable);
 159                 flush_current_id(patchlen, &oid, &result);
 160                 oidcpy(&oid, &n);
 161         }
 162         strbuf_release(&line_buf);
 163 }
 164
 165 static const char patch_id_usage[] = "git patch-id [--stable | --unstable]";
 166
 167 static int git_patch_id_config(const char *var, const char *value, void *cb)
 168 {
 169         int *stable = cb;
 170
 171         if (!strcmp(var, "patchid.stable")) {
 172                 *stable = git_config_bool(var, value);
 173                 return 0;
 174         }
 175
 176         return git_default_config(var, value, cb);
 177 }
 178
 179 int cmd_patch_id(int argc, const char **argv, const char *prefix)
 180 {
 181         int stable = -1;
 182
 183         git_config(git_patch_id_config, &stable);
 184
 185         /* If nothing is set, default to unstable. */
 186         if (stable < 0)
 187                 stable = 0;
 188
 189         if (argc == 2 && !strcmp(argv[1], "--stable"))
 190                 stable = 1;
 191         else if (argc == 2 && !strcmp(argv[1], "--unstable"))
 192                 stable = 0;
 193         else if (argc != 1)
 194                 usage(patch_id_usage);
 195
 196         generate_id_list(stable);
 197         return 0;
 198 }