Andrew's git - gitweb.git/blob

   1/*
   2 * "git reset" builtin command
   3 *
   4 * Copyright (c) 2007 Carlos Rica
   5 *
   6 * Based on git-reset.sh, which is
   7 *
   8 * Copyright (c) 2005, 2006 Linus Torvalds and Junio C Hamano
   9 */
  10#include "cache.h"
  11#include "tag.h"
  12#include "object.h"
  13#include "commit.h"
  14#include "run-command.h"
  15#include "refs.h"
  16#include "diff.h"
  17#include "diffcore.h"
  18#include "tree.h"
  19#include "branch.h"
  20
  21static const char builtin_reset_usage[] =
  22"git-reset [--mixed | --soft | --hard] [-q] [<commit-ish>] [ [--] <paths>...]";
  23
  24static char *args_to_str(const char **argv)
  25{
  26        char *buf = NULL;
  27        unsigned long len, space = 0, nr = 0;
  28
  29        for (; *argv; argv++) {
  30                len = strlen(*argv);
  31                ALLOC_GROW(buf, nr + 1 + len, space);
  32                if (nr)
  33                        buf[nr++] = ' ';
  34                memcpy(buf + nr, *argv, len);
  35                nr += len;
  36        }
  37        ALLOC_GROW(buf, nr + 1, space);
  38        buf[nr] = '\0';
  39
  40        return buf;
  41}
  42
  43static inline int is_merge(void)
  44{
  45        return !access(git_path("MERGE_HEAD"), F_OK);
  46}
  47
  48static int reset_index_file(const unsigned char *sha1, int is_hard_reset)
  49{
  50        int i = 0;
  51        const char *args[6];
  52
  53        args[i++] = "read-tree";
  54        args[i++] = "-v";
  55        args[i++] = "--reset";
  56        if (is_hard_reset)
  57                args[i++] = "-u";
  58        args[i++] = sha1_to_hex(sha1);
  59        args[i] = NULL;
  60
  61        return run_command_v_opt(args, RUN_GIT_CMD);
  62}
  63
  64static void print_new_head_line(struct commit *commit)
  65{
  66        const char *hex, *body;
  67
  68        hex = find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV);
  69        printf("HEAD is now at %s", hex);
  70        body = strstr(commit->buffer, "\n\n");
  71        if (body) {
  72                const char *eol;
  73                size_t len;
  74                body += 2;
  75                eol = strchr(body, '\n');
  76                len = eol ? eol - body : strlen(body);
  77                printf(" %.*s\n", (int) len, body);
  78        }
  79        else
  80                printf("\n");
  81}
  82
  83static int update_index_refresh(int fd, struct lock_file *index_lock)
  84{
  85        int result;
  86
  87        if (!index_lock) {
  88                index_lock = xcalloc(1, sizeof(struct lock_file));
  89                fd = hold_locked_index(index_lock, 1);
  90        }
  91
  92        if (read_cache() < 0)
  93                return error("Could not read index");
  94        result = refresh_cache(0) ? 1 : 0;
  95        if (write_cache(fd, active_cache, active_nr) ||
  96                        commit_locked_index(index_lock))
  97                return error ("Could not refresh index");
  98        return result;
  99}
 100
 101static void update_index_from_diff(struct diff_queue_struct *q,
 102                struct diff_options *opt, void *data)
 103{
 104        int i;
 105        int *discard_flag = data;
 106
 107        /* do_diff_cache() mangled the index */
 108        discard_cache();
 109        *discard_flag = 1;
 110        read_cache();
 111
 112        for (i = 0; i < q->nr; i++) {
 113                struct diff_filespec *one = q->queue[i]->one;
 114                if (one->mode) {
 115                        struct cache_entry *ce;
 116                        ce = make_cache_entry(one->mode, one->sha1, one->path,
 117                                0, 0);
 118                        add_cache_entry(ce, ADD_CACHE_OK_TO_ADD |
 119                                ADD_CACHE_OK_TO_REPLACE);
 120                } else
 121                        remove_file_from_cache(one->path);
 122        }
 123}
 124
 125static int read_from_tree(const char *prefix, const char **argv,
 126                unsigned char *tree_sha1)
 127{
 128        struct lock_file *lock = xcalloc(1, sizeof(struct lock_file));
 129        int index_fd, index_was_discarded = 0;
 130        struct diff_options opt;
 131
 132        memset(&opt, 0, sizeof(opt));
 133        diff_tree_setup_paths(get_pathspec(prefix, (const char **)argv), &opt);
 134        opt.output_format = DIFF_FORMAT_CALLBACK;
 135        opt.format_callback = update_index_from_diff;
 136        opt.format_callback_data = &index_was_discarded;
 137
 138        index_fd = hold_locked_index(lock, 1);
 139        index_was_discarded = 0;
 140        read_cache();
 141        if (do_diff_cache(tree_sha1, &opt))
 142                return 1;
 143        diffcore_std(&opt);
 144        diff_flush(&opt);
 145        diff_tree_release_paths(&opt);
 146
 147        if (!index_was_discarded)
 148                /* The index is still clobbered from do_diff_cache() */
 149                discard_cache();
 150        return update_index_refresh(index_fd, lock);
 151}
 152
 153static void prepend_reflog_action(const char *action, char *buf, size_t size)
 154{
 155        const char *sep = ": ";
 156        const char *rla = getenv("GIT_REFLOG_ACTION");
 157        if (!rla)
 158                rla = sep = "";
 159        if (snprintf(buf, size, "%s%s%s", rla, sep, action) >= size)
 160                warning("Reflog action message too long: %.*s...", 50, buf);
 161}
 162
 163enum reset_type { MIXED, SOFT, HARD, NONE };
 164static const char *reset_type_names[] = { "mixed", "soft", "hard", NULL };
 165
 166int cmd_reset(int argc, const char **argv, const char *prefix)
 167{
 168        int i = 1, reset_type = NONE, update_ref_status = 0, quiet = 0;
 169        const char *rev = "HEAD";
 170        unsigned char sha1[20], *orig = NULL, sha1_orig[20],
 171                                *old_orig = NULL, sha1_old_orig[20];
 172        struct commit *commit;
 173        char *reflog_action, msg[1024];
 174
 175        git_config(git_default_config);
 176
 177        reflog_action = args_to_str(argv);
 178        setenv("GIT_REFLOG_ACTION", reflog_action, 0);
 179
 180        while (i < argc) {
 181                if (!strcmp(argv[i], "--mixed")) {
 182                        reset_type = MIXED;
 183                        i++;
 184                }
 185                else if (!strcmp(argv[i], "--soft")) {
 186                        reset_type = SOFT;
 187                        i++;
 188                }
 189                else if (!strcmp(argv[i], "--hard")) {
 190                        reset_type = HARD;
 191                        i++;
 192                }
 193                else if (!strcmp(argv[i], "-q")) {
 194                        quiet = 1;
 195                        i++;
 196                }
 197                else
 198                        break;
 199        }
 200
 201        if (i < argc && argv[i][0] != '-')
 202                rev = argv[i++];
 203
 204        if (get_sha1(rev, sha1))
 205                die("Failed to resolve '%s' as a valid ref.", rev);
 206
 207        commit = lookup_commit_reference(sha1);
 208        if (!commit)
 209                die("Could not parse object '%s'.", rev);
 210        hashcpy(sha1, commit->object.sha1);
 211
 212        if (i < argc && !strcmp(argv[i], "--"))
 213                i++;
 214        else if (i < argc && argv[i][0] == '-')
 215                usage(builtin_reset_usage);
 216
 217        /* git reset tree [--] paths... can be used to
 218         * load chosen paths from the tree into the index without
 219         * affecting the working tree nor HEAD. */
 220        if (i < argc) {
 221                if (reset_type == MIXED)
 222                        warning("--mixed option is deprecated with paths.");
 223                else if (reset_type != NONE)
 224                        die("Cannot do %s reset with paths.",
 225                                        reset_type_names[reset_type]);
 226                return read_from_tree(prefix, argv + i, sha1);
 227        }
 228        if (reset_type == NONE)
 229                reset_type = MIXED; /* by default */
 230
 231        if (reset_type == HARD && is_bare_repository())
 232                die("hard reset makes no sense in a bare repository");
 233
 234        /* Soft reset does not touch the index file nor the working tree
 235         * at all, but requires them in a good order.  Other resets reset
 236         * the index file to the tree object we are switching to. */
 237        if (reset_type == SOFT) {
 238                if (is_merge() || read_cache() < 0 || unmerged_cache())
 239                        die("Cannot do a soft reset in the middle of a merge.");
 240        }
 241        else if (reset_index_file(sha1, (reset_type == HARD)))
 242                die("Could not reset index file to revision '%s'.", rev);
 243
 244        /* Any resets update HEAD to the head being switched to,
 245         * saving the previous head in ORIG_HEAD before. */
 246        if (!get_sha1("ORIG_HEAD", sha1_old_orig))
 247                old_orig = sha1_old_orig;
 248        if (!get_sha1("HEAD", sha1_orig)) {
 249                orig = sha1_orig;
 250                prepend_reflog_action("updating ORIG_HEAD", msg, sizeof(msg));
 251                update_ref(msg, "ORIG_HEAD", orig, old_orig, 0, MSG_ON_ERR);
 252        }
 253        else if (old_orig)
 254                delete_ref("ORIG_HEAD", old_orig);
 255        prepend_reflog_action("updating HEAD", msg, sizeof(msg));
 256        update_ref_status = update_ref(msg, "HEAD", sha1, orig, 0, MSG_ON_ERR);
 257
 258        switch (reset_type) {
 259        case HARD:
 260                if (!update_ref_status && !quiet)
 261                        print_new_head_line(commit);
 262                break;
 263        case SOFT: /* Nothing else to do. */
 264                break;
 265        case MIXED: /* Report what has not been updated. */
 266                update_index_refresh(0, NULL);
 267                break;
 268        }
 269
 270        remove_branch_state();
 271
 272        free(reflog_action);
 273
 274        return update_ref_status;
 275}