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
  20static const char builtin_reset_usage[] =
  21"git-reset [--mixed | --soft | --hard] [-q] [<commit-ish>] [ [--] <paths>...]";
  22
  23static char *args_to_str(const char **argv)
  24{
  25        char *buf = NULL;
  26        unsigned long len, space = 0, nr = 0;
  27
  28        for (; *argv; argv++) {
  29                len = strlen(*argv);
  30                ALLOC_GROW(buf, nr + 1 + len, space);
  31                if (nr)
  32                        buf[nr++] = ' ';
  33                memcpy(buf + nr, *argv, len);
  34                nr += len;
  35        }
  36        ALLOC_GROW(buf, nr + 1, space);
  37        buf[nr] = '\0';
  38
  39        return buf;
  40}
  41
  42static inline int is_merge(void)
  43{
  44        return !access(git_path("MERGE_HEAD"), F_OK);
  45}
  46
  47static int unmerged_files(void)
  48{
  49        int i;
  50        read_cache();
  51        for (i = 0; i < active_nr; i++) {
  52                struct cache_entry *ce = active_cache[i];
  53                if (ce_stage(ce))
  54                        return 1;
  55        }
  56        return 0;
  57}
  58
  59static int reset_index_file(const unsigned char *sha1, int is_hard_reset)
  60{
  61        int i = 0;
  62        const char *args[6];
  63
  64        args[i++] = "read-tree";
  65        args[i++] = "-v";
  66        args[i++] = "--reset";
  67        if (is_hard_reset)
  68                args[i++] = "-u";
  69        args[i++] = sha1_to_hex(sha1);
  70        args[i] = NULL;
  71
  72        return run_command_v_opt(args, RUN_GIT_CMD);
  73}
  74
  75static void print_new_head_line(struct commit *commit)
  76{
  77        const char *hex, *dots = "...", *body;
  78
  79        hex = find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV);
  80        if (!hex) {
  81                hex = sha1_to_hex(commit->object.sha1);
  82                dots = "";
  83        }
  84        printf("HEAD is now at %s%s", hex, dots);
  85        body = strstr(commit->buffer, "\n\n");
  86        if (body) {
  87                const char *eol;
  88                size_t len;
  89                body += 2;
  90                eol = strchr(body, '\n');
  91                len = eol ? eol - body : strlen(body);
  92                printf(" %.*s\n", (int) len, body);
  93        }
  94        else
  95                printf("\n");
  96}
  97
  98static int update_index_refresh(int fd, struct lock_file *index_lock)
  99{
 100        int result;
 101
 102        if (!index_lock) {
 103                index_lock = xcalloc(1, sizeof(struct lock_file));
 104                fd = hold_locked_index(index_lock, 1);
 105        }
 106
 107        if (read_cache() < 0)
 108                return error("Could not read index");
 109        result = refresh_cache(0) ? 1 : 0;
 110        if (write_cache(fd, active_cache, active_nr) ||
 111                        close(fd) ||
 112                        commit_locked_index(index_lock))
 113                return error ("Could not refresh index");
 114        return result;
 115}
 116
 117static void update_index_from_diff(struct diff_queue_struct *q,
 118                struct diff_options *opt, void *data)
 119{
 120        int i;
 121        int *discard_flag = data;
 122
 123        /* do_diff_cache() mangled the index */
 124        discard_cache();
 125        *discard_flag = 1;
 126        read_cache();
 127
 128        for (i = 0; i < q->nr; i++) {
 129                struct diff_filespec *one = q->queue[i]->one;
 130                if (one->mode) {
 131                        struct cache_entry *ce;
 132                        ce = make_cache_entry(one->mode, one->sha1, one->path,
 133                                0, 0);
 134                        add_cache_entry(ce, ADD_CACHE_OK_TO_ADD |
 135                                ADD_CACHE_OK_TO_REPLACE);
 136                } else
 137                        remove_file_from_cache(one->path);
 138        }
 139}
 140
 141static int read_from_tree(const char *prefix, const char **argv,
 142                unsigned char *tree_sha1)
 143{
 144        struct lock_file *lock = xcalloc(1, sizeof(struct lock_file));
 145        int index_fd, index_was_discarded = 0;
 146        struct diff_options opt;
 147
 148        memset(&opt, 0, sizeof(opt));
 149        diff_tree_setup_paths(get_pathspec(prefix, (const char **)argv), &opt);
 150        opt.output_format = DIFF_FORMAT_CALLBACK;
 151        opt.format_callback = update_index_from_diff;
 152        opt.format_callback_data = &index_was_discarded;
 153
 154        index_fd = hold_locked_index(lock, 1);
 155        index_was_discarded = 0;
 156        read_cache();
 157        if (do_diff_cache(tree_sha1, &opt))
 158                return 1;
 159        diffcore_std(&opt);
 160        diff_flush(&opt);
 161        diff_tree_release_paths(&opt);
 162
 163        if (!index_was_discarded)
 164                /* The index is still clobbered from do_diff_cache() */
 165                discard_cache();
 166        return update_index_refresh(index_fd, lock);
 167}
 168
 169static void prepend_reflog_action(const char *action, char *buf, size_t size)
 170{
 171        const char *sep = ": ";
 172        const char *rla = getenv("GIT_REFLOG_ACTION");
 173        if (!rla)
 174                rla = sep = "";
 175        if (snprintf(buf, size, "%s%s%s", rla, sep, action) >= size)
 176                warning("Reflog action message too long: %.*s...", 50, buf);
 177}
 178
 179enum reset_type { MIXED, SOFT, HARD, NONE };
 180static const char *reset_type_names[] = { "mixed", "soft", "hard", NULL };
 181
 182int cmd_reset(int argc, const char **argv, const char *prefix)
 183{
 184        int i = 1, reset_type = NONE, update_ref_status = 0, quiet = 0;
 185        const char *rev = "HEAD";
 186        unsigned char sha1[20], *orig = NULL, sha1_orig[20],
 187                                *old_orig = NULL, sha1_old_orig[20];
 188        struct commit *commit;
 189        char *reflog_action, msg[1024];
 190
 191        git_config(git_default_config);
 192
 193        reflog_action = args_to_str(argv);
 194        setenv("GIT_REFLOG_ACTION", reflog_action, 0);
 195
 196        while (i < argc) {
 197                if (!strcmp(argv[i], "--mixed")) {
 198                        reset_type = MIXED;
 199                        i++;
 200                }
 201                else if (!strcmp(argv[i], "--soft")) {
 202                        reset_type = SOFT;
 203                        i++;
 204                }
 205                else if (!strcmp(argv[i], "--hard")) {
 206                        reset_type = HARD;
 207                        i++;
 208                }
 209                else if (!strcmp(argv[i], "-q")) {
 210                        quiet = 1;
 211                        i++;
 212                }
 213                else
 214                        break;
 215        }
 216
 217        if (i < argc && argv[i][0] != '-')
 218                rev = argv[i++];
 219
 220        if (get_sha1(rev, sha1))
 221                die("Failed to resolve '%s' as a valid ref.", rev);
 222
 223        commit = lookup_commit_reference(sha1);
 224        if (!commit)
 225                die("Could not parse object '%s'.", rev);
 226        hashcpy(sha1, commit->object.sha1);
 227
 228        if (i < argc && !strcmp(argv[i], "--"))
 229                i++;
 230        else if (i < argc && argv[i][0] == '-')
 231                usage(builtin_reset_usage);
 232
 233        /* git reset tree [--] paths... can be used to
 234         * load chosen paths from the tree into the index without
 235         * affecting the working tree nor HEAD. */
 236        if (i < argc) {
 237                if (reset_type == MIXED)
 238                        warning("--mixed option is deprecated with paths.");
 239                else if (reset_type != NONE)
 240                        die("Cannot do %s reset with paths.",
 241                                        reset_type_names[reset_type]);
 242                return read_from_tree(prefix, argv + i, sha1);
 243        }
 244        if (reset_type == NONE)
 245                reset_type = MIXED; /* by default */
 246
 247        if (reset_type == HARD && is_bare_repository())
 248                die("hard reset makes no sense in a bare repository");
 249
 250        /* Soft reset does not touch the index file nor the working tree
 251         * at all, but requires them in a good order.  Other resets reset
 252         * the index file to the tree object we are switching to. */
 253        if (reset_type == SOFT) {
 254                if (is_merge() || unmerged_files())
 255                        die("Cannot do a soft reset in the middle of a merge.");
 256        }
 257        else if (reset_index_file(sha1, (reset_type == HARD)))
 258                die("Could not reset index file to revision '%s'.", rev);
 259
 260        /* Any resets update HEAD to the head being switched to,
 261         * saving the previous head in ORIG_HEAD before. */
 262        if (!get_sha1("ORIG_HEAD", sha1_old_orig))
 263                old_orig = sha1_old_orig;
 264        if (!get_sha1("HEAD", sha1_orig)) {
 265                orig = sha1_orig;
 266                prepend_reflog_action("updating ORIG_HEAD", msg, sizeof(msg));
 267                update_ref(msg, "ORIG_HEAD", orig, old_orig, 0, MSG_ON_ERR);
 268        }
 269        else if (old_orig)
 270                delete_ref("ORIG_HEAD", old_orig);
 271        prepend_reflog_action("updating HEAD", msg, sizeof(msg));
 272        update_ref_status = update_ref(msg, "HEAD", sha1, orig, 0, MSG_ON_ERR);
 273
 274        switch (reset_type) {
 275        case HARD:
 276                if (!update_ref_status && !quiet)
 277                        print_new_head_line(commit);
 278                break;
 279        case SOFT: /* Nothing else to do. */
 280                break;
 281        case MIXED: /* Report what has not been updated. */
 282                update_index_refresh(0, NULL);
 283                break;
 284        }
 285
 286        unlink(git_path("MERGE_HEAD"));
 287        unlink(git_path("rr-cache/MERGE_RR"));
 288        unlink(git_path("MERGE_MSG"));
 289        unlink(git_path("SQUASH_MSG"));
 290
 291        free(reflog_action);
 292
 293        return update_ref_status;
 294}