builtin/patch-id.c

   1 #include "builtin.h"
   2 #include "config.h"
   3
   4 static void flush_current_id(int patchlen, struct object_id *id, struct object_id *result)
   5 {
   6         char name[50];
   7
   8         if (!patchlen)
   9                 return;
  10
  11         memcpy(name, oid_to_hex(id), GIT_SHA1_HEXSZ + 1);
  12         printf("%s %s\n", oid_to_hex(result), name);
  13 }
  14
  15 static int remove_space(char *line)
  16 {
  17         char *src = line;
  18         char *dst = line;
  19         unsigned char c;
  20
  21         while ((c = *src++) != '\0') {
  22                 if (!isspace(c))
  23                         *dst++ = c;
  24         }
  25         return dst - line;
  26 }
  27
  28 static int scan_hunk_header(const char *p, int *p_before, int *p_after)
  29 {
  30         static const char digits[] = "0123456789";
  31         const char *q, *r;
  32         int n;
  33
  34         q = p + 4;
  35         n = strspn(q, digits);
  36         if (q[n] == ',') {
  37                 q += n + 1;
  38                 n = strspn(q, digits);
  39         }
  40         if (n == 0 || q[n] != ' ' || q[n+1] != '+')
  41                 return 0;
  42
  43         r = q + n + 2;
  44         n = strspn(r, digits);
  45         if (r[n] == ',') {
  46                 r += n + 1;
  47                 n = strspn(r, digits);
  48         }
  49         if (n == 0)
  50                 return 0;
  51
  52         *p_before = atoi(q);
  53         *p_after = atoi(r);
  54         return 1;
  55 }
  56
  57 static void flush_one_hunk(struct object_id *result, git_SHA_CTX *ctx)
  58 {
  59         unsigned char hash[GIT_MAX_RAWSZ];
  60         unsigned short carry = 0;
  61         int i;
  62
  63         git_SHA1_Final(hash, ctx);
  64         git_SHA1_Init(ctx);
  65         /* 20-byte sum, with carry */
  66         for (i = 0; i < GIT_SHA1_RAWSZ; ++i) {
  67                 carry += result->hash[i] + hash[i];
  68                 result->hash[i] = carry;
  69                 carry >>= 8;
  70         }
  71 }
  72
  73 static int get_one_patchid(struct object_id *next_oid, struct object_id *result,
  74                            struct strbuf *line_buf, int stable)
  75 {
  76         int patchlen = 0, found_next = 0;
  77         int before = -1, after = -1;
  78         git_SHA_CTX ctx;
  79
  80         git_SHA1_Init(&ctx);
  81         oidclr(result);
  82
  83         while (strbuf_getwholeline(line_buf, stdin, '\n') != EOF) {
  84                 char *line = line_buf->buf;
  85                 const char *p = line;
  86                 int len;
  87
  88                 if (!skip_prefix(line, "diff-tree ", &p) &&
  89                     !skip_prefix(line, "commit ", &p) &&
  90                     !skip_prefix(line, "From ", &p) &&
  91                     starts_with(line, "\\ ") && 12 < strlen(line))
  92                         continue;
  93
  94                 if (!get_oid_hex(p, next_oid)) {
  95                         found_next = 1;
  96                         break;
  97                 }
  98
  99                 /* Ignore commit comments */
 100                 if (!patchlen && !starts_with(line, "diff "))
 101                         continue;
 102
 103                 /* Parsing diff header?  */
 104                 if (before == -1) {
 105                         if (starts_with(line, "index "))
 106                                 continue;
 107                         else if (starts_with(line, "--- "))
 108                                 before = after = 1;
 109                         else if (!isalpha(line[0]))
 110                                 break;
 111                 }
 112
 113                 /* Looking for a valid hunk header?  */
 114                 if (before == 0 && after == 0) {
 115                         if (starts_with(line, "@@ -")) {
 116                                 /* Parse next hunk, but ignore line numbers.  */
 117                                 scan_hunk_header(line, &before, &after);
 118                                 continue;
 119                         }
 120
 121                         /* Split at the end of the patch.  */
 122                         if (!starts_with(line, "diff "))
 123                                 break;
 124
 125                         /* Else we're parsing another header.  */
 126                         if (stable)
 127                                 flush_one_hunk(result, &ctx);
 128                         before = after = -1;
 129                 }
 130
 131                 /* If we get here, we're inside a hunk.  */
 132                 if (line[0] == '-' || line[0] == ' ')
 133                         before--;
 134                 if (line[0] == '+' || line[0] == ' ')
 135                         after--;
 136
 137                 /* Compute the sha without whitespace */
 138                 len = remove_space(line);
 139                 patchlen += len;
 140                 git_SHA1_Update(&ctx, line, len);
 141         }
 142
 143         if (!found_next)
 144                 oidclr(next_oid);
 145
 146         flush_one_hunk(result, &ctx);
 147
 148         return patchlen;
 149 }
 150
 151 static void generate_id_list(int stable)
 152 {
 153         struct object_id oid, n, result;
 154         int patchlen;
 155         struct strbuf line_buf = STRBUF_INIT;
 156
 157         oidclr(&oid);
 158         while (!feof(stdin)) {
 159                 patchlen = get_one_patchid(&n, &result, &line_buf, stable);
 160                 flush_current_id(patchlen, &oid, &result);
 161                 oidcpy(&oid, &n);
 162         }
 163         strbuf_release(&line_buf);
 164 }
 165
 166 static const char patch_id_usage[] = "git patch-id [--stable | --unstable]";
 167
 168 static int git_patch_id_config(const char *var, const char *value, void *cb)
 169 {
 170         int *stable = cb;
 171
 172         if (!strcmp(var, "patchid.stable")) {
 173                 *stable = git_config_bool(var, value);
 174                 return 0;
 175         }
 176
 177         return git_default_config(var, value, cb);
 178 }
 179
 180 int cmd_patch_id(int argc, const char **argv, const char *prefix)
 181 {
 182         int stable = -1;
 183
 184         git_config(git_patch_id_config, &stable);
 185
 186         /* If nothing is set, default to unstable. */
 187         if (stable < 0)
 188                 stable = 0;
 189
 190         if (argc == 2 && !strcmp(argv[1], "--stable"))
 191                 stable = 1;
 192         else if (argc == 2 && !strcmp(argv[1], "--unstable"))
 193                 stable = 0;
 194         else if (argc != 1)
 195                 usage(patch_id_usage);
 196
 197         generate_id_list(stable);
 198         return 0;
 199 }