builtin/pull.c

   1 /*
   2  * Builtin "git pull"
   3  *
   4  * Based on git-pull.sh by Junio C Hamano
   5  *
   6  * Fetch one or more remote refs and merge it/them into the current HEAD.
   7  */
   8 #include "cache.h"
   9 #include "builtin.h"
  10 #include "parse-options.h"
  11 #include "exec_cmd.h"
  12 #include "run-command.h"
  13
  14 static const char * const pull_usage[] = {
  15         N_("git pull [options] [<repository> [<refspec>...]]"),
  16         NULL
  17 };
  18
  19 static struct option pull_options[] = {
  20         OPT_END()
  21 };
  22
  23 /**
  24  * Parses argv into [<repo> [<refspecs>...]], returning their values in `repo`
  25  * as a string and `refspecs` as a null-terminated array of strings. If `repo`
  26  * is not provided in argv, it is set to NULL.
  27  */
  28 static void parse_repo_refspecs(int argc, const char **argv, const char **repo,
  29                 const char ***refspecs)
  30 {
  31         if (argc > 0) {
  32                 *repo = *argv++;
  33                 argc--;
  34         } else
  35                 *repo = NULL;
  36         *refspecs = argv;
  37 }
  38
  39 /**
  40  * Runs git-fetch, returning its exit status. `repo` and `refspecs` are the
  41  * repository and refspecs to fetch, or NULL if they are not provided.
  42  */
  43 static int run_fetch(const char *repo, const char **refspecs)
  44 {
  45         struct argv_array args = ARGV_ARRAY_INIT;
  46         int ret;
  47
  48         argv_array_pushl(&args, "fetch", "--update-head-ok", NULL);
  49         if (repo) {
  50                 argv_array_push(&args, repo);
  51                 argv_array_pushv(&args, refspecs);
  52         } else if (*refspecs)
  53                 die("BUG: refspecs without repo?");
  54         ret = run_command_v_opt(args.argv, RUN_GIT_CMD);
  55         argv_array_clear(&args);
  56         return ret;
  57 }
  58
  59 /**
  60  * Runs git-merge, returning its exit status.
  61  */
  62 static int run_merge(void)
  63 {
  64         int ret;
  65         struct argv_array args = ARGV_ARRAY_INIT;
  66
  67         argv_array_pushl(&args, "merge", NULL);
  68         argv_array_push(&args, "FETCH_HEAD");
  69         ret = run_command_v_opt(args.argv, RUN_GIT_CMD);
  70         argv_array_clear(&args);
  71         return ret;
  72 }
  73
  74 int cmd_pull(int argc, const char **argv, const char *prefix)
  75 {
  76         const char *repo, **refspecs;
  77
  78         if (!getenv("_GIT_USE_BUILTIN_PULL")) {
  79                 const char *path = mkpath("%s/git-pull", git_exec_path());
  80
  81                 if (sane_execvp(path, (char **)argv) < 0)
  82                         die_errno("could not exec %s", path);
  83         }
  84
  85         argc = parse_options(argc, argv, prefix, pull_options, pull_usage, 0);
  86
  87         parse_repo_refspecs(argc, argv, &repo, &refspecs);
  88
  89         if (run_fetch(repo, refspecs))
  90                 return 1;
  91
  92         return run_merge();
  93 }