builtin/merge-file.c

   1 #include "builtin.h"
   2 #include "abspath.h"
   3 #include "diff.h"
   4 #include "hex.h"
   5 #include "object-name.h"
   6 #include "object-store.h"
   7 #include "config.h"
   8 #include "gettext.h"
   9 #include "setup.h"
  10 #include "xdiff/xdiff.h"
  11 #include "xdiff-interface.h"
  12 #include "parse-options.h"
  13
  14 static const char *const merge_file_usage[] = {
  15         N_("git merge-file [<options>] [-L <name1> [-L <orig> [-L <name2>]]] <file1> <orig-file> <file2>"),
  16         NULL
  17 };
  18
  19 static int label_cb(const struct option *opt, const char *arg, int unset)
  20 {
  21         static int label_count = 0;
  22         const char **names = (const char **)opt->value;
  23
  24         BUG_ON_OPT_NEG(unset);
  25
  26         if (label_count >= 3)
  27                 return error("too many labels on the command line");
  28         names[label_count++] = arg;
  29         return 0;
  30 }
  31
  32 static int set_diff_algorithm(xpparam_t *xpp,
  33                               const char *alg)
  34 {
  35         long diff_algorithm = parse_algorithm_value(alg);
  36         if (diff_algorithm < 0)
  37                 return -1;
  38         xpp->flags = (xpp->flags & ~XDF_DIFF_ALGORITHM_MASK) | diff_algorithm;
  39         return 0;
  40 }
  41
  42 static int diff_algorithm_cb(const struct option *opt,
  43                                 const char *arg, int unset)
  44 {
  45         xpparam_t *xpp = opt->value;
  46
  47         BUG_ON_OPT_NEG(unset);
  48
  49         if (set_diff_algorithm(xpp, arg))
  50                 return error(_("option diff-algorithm accepts \"myers\", "
  51                                "\"minimal\", \"patience\" and \"histogram\""));
  52
  53         return 0;
  54 }
  55
  56 int cmd_merge_file(int argc, const char **argv, const char *prefix)
  57 {
  58         const char *names[3] = { 0 };
  59         mmfile_t mmfs[3] = { 0 };
  60         mmbuffer_t result = { 0 };
  61         xmparam_t xmp = { 0 };
  62         int ret = 0, i = 0, to_stdout = 0, object_id = 0;
  63         int quiet = 0;
  64         struct option options[] = {
  65                 OPT_BOOL('p', "stdout", &to_stdout, N_("send results to standard output")),
  66                 OPT_BOOL(0,   "object-id", &object_id, N_("use object IDs instead of filenames")),
  67                 OPT_SET_INT(0, "diff3", &xmp.style, N_("use a diff3 based merge"), XDL_MERGE_DIFF3),
  68                 OPT_SET_INT(0, "zdiff3", &xmp.style, N_("use a zealous diff3 based merge"),
  69                                 XDL_MERGE_ZEALOUS_DIFF3),
  70                 OPT_SET_INT(0, "ours", &xmp.favor, N_("for conflicts, use our version"),
  71                             XDL_MERGE_FAVOR_OURS),
  72                 OPT_SET_INT(0, "theirs", &xmp.favor, N_("for conflicts, use their version"),
  73                             XDL_MERGE_FAVOR_THEIRS),
  74                 OPT_SET_INT(0, "union", &xmp.favor, N_("for conflicts, use a union version"),
  75                             XDL_MERGE_FAVOR_UNION),
  76                 OPT_CALLBACK_F(0, "diff-algorithm", &xmp.xpp, N_("<algorithm>"),
  77                              N_("choose a diff algorithm"),
  78                              PARSE_OPT_NONEG, diff_algorithm_cb),
  79                 OPT_INTEGER(0, "marker-size", &xmp.marker_size,
  80                             N_("for conflicts, use this marker size")),
  81                 OPT__QUIET(&quiet, N_("do not warn about conflicts")),
  82                 OPT_CALLBACK('L', NULL, names, N_("name"),
  83                              N_("set labels for file1/orig-file/file2"), &label_cb),
  84                 OPT_END(),
  85         };
  86
  87         xmp.level = XDL_MERGE_ZEALOUS_ALNUM;
  88         xmp.style = 0;
  89         xmp.favor = 0;
  90
  91         if (startup_info->have_repository) {
  92                 /* Read the configuration file */
  93                 git_config(git_xmerge_config, NULL);
  94                 if (0 <= git_xmerge_style)
  95                         xmp.style = git_xmerge_style;
  96         }
  97
  98         argc = parse_options(argc, argv, prefix, options, merge_file_usage, 0);
  99         if (argc != 3)
 100                 usage_with_options(merge_file_usage, options);
 101         if (quiet) {
 102                 if (!freopen("/dev/null", "w", stderr))
 103                         return error_errno("failed to redirect stderr to /dev/null");
 104         }
 105
 106         if (object_id)
 107                 setup_git_directory();
 108
 109         for (i = 0; i < 3; i++) {
 110                 char *fname;
 111                 struct object_id oid;
 112                 mmfile_t *mmf = mmfs + i;
 113
 114                 if (!names[i])
 115                         names[i] = argv[i];
 116
 117                 fname = prefix_filename(prefix, argv[i]);
 118
 119                 if (object_id) {
 120                         if (repo_get_oid(the_repository, argv[i], &oid))
 121                                 ret = error(_("object '%s' does not exist"),
 122                                               argv[i]);
 123                         else if (!oideq(&oid, the_hash_algo->empty_blob))
 124                                 read_mmblob(mmf, &oid);
 125                         else
 126                                 read_mmfile(mmf, "/dev/null");
 127                 } else if (read_mmfile(mmf, fname)) {
 128                         ret = -1;
 129                 }
 130                 if (ret != -1 && (mmf->size > MAX_XDIFF_SIZE ||
 131                     buffer_is_binary(mmf->ptr, mmf->size))) {
 132                         ret = error("Cannot merge binary files: %s",
 133                                     argv[i]);
 134                 }
 135
 136                 free(fname);
 137                 if (ret)
 138                         goto cleanup;
 139
 140         }
 141
 142         xmp.ancestor = names[1];
 143         xmp.file1 = names[0];
 144         xmp.file2 = names[2];
 145         ret = xdl_merge(mmfs + 1, mmfs + 0, mmfs + 2, &xmp, &result);
 146
 147         if (ret >= 0) {
 148                 if (object_id && !to_stdout) {
 149                         struct object_id oid;
 150                         if (result.size) {
 151                                 if (write_object_file(result.ptr, result.size, OBJ_BLOB, &oid) < 0)
 152                                         ret = error(_("Could not write object file"));
 153                         } else {
 154                                 oidcpy(&oid, the_hash_algo->empty_blob);
 155                         }
 156                         if (ret >= 0)
 157                                 printf("%s\n", oid_to_hex(&oid));
 158                 } else {
 159                         const char *filename = argv[0];
 160                         char *fpath = prefix_filename(prefix, argv[0]);
 161                         FILE *f = to_stdout ? stdout : fopen(fpath, "wb");
 162
 163                         if (!f)
 164                                 ret = error_errno("Could not open %s for writing",
 165                                                   filename);
 166                         else if (result.size &&
 167                                  fwrite(result.ptr, result.size, 1, f) != 1)
 168                                 ret = error_errno("Could not write to %s", filename);
 169                         else if (fclose(f))
 170                                 ret = error_errno("Could not close %s", filename);
 171                         free(fpath);
 172                 }
 173                 free(result.ptr);
 174         }
 175
 176         if (ret > 127)
 177                 ret = 127;
 178
 179 cleanup:
 180         for (i = 0; i < 3; i++)
 181                 free(mmfs[i].ptr);
 182
 183         return ret;
 184 }