use delta index data when finding best delta matches

[git.git] / update-index.c

/*
 * GIT - The information manager from hell
 *
 * Copyright (C) Linus Torvalds, 2005
 */
#include "cache.h"
#include "strbuf.h"
#include "quote.h"
#include "tree-walk.h"

/*
 * Default to not allowing changes to the list of files. The
 * tool doesn't actually care, but this makes it harder to add
 * files to the revision control by mistake by doing something
 * like "git-update-index *" and suddenly having all the object
 * files be revision controlled.
 */
static int allow_add;
static int allow_remove;
static int allow_replace;
static int allow_unmerged; /* --refresh needing merge is not error */
static int not_new; /* --refresh not having working tree files is not error */
static int quiet; /* --refresh needing update is not error */
static int info_only;
static int force_remove;
static int verbose;
static int mark_valid_only = 0;
#define MARK_VALID 1
#define UNMARK_VALID 2


/* Three functions to allow overloaded pointer return; see linux/err.h */
static inline void *ERR_PTR(long error)
{
        return (void *) error;
}

static inline long PTR_ERR(const void *ptr)
{
        return (long) ptr;
}

static inline long IS_ERR(const void *ptr)
{
        return (unsigned long)ptr > (unsigned long)-1000L;
}

static void report(const char *fmt, ...)
{
        va_list vp;

        if (!verbose)
                return;

        va_start(vp, fmt);
        vprintf(fmt, vp);
        putchar('\n');
        va_end(vp);
}

static int mark_valid(const char *path)
{
        int namelen = strlen(path);
        int pos = cache_name_pos(path, namelen);
        if (0 <= pos) {
                switch (mark_valid_only) {
                case MARK_VALID:
                        active_cache[pos]->ce_flags |= htons(CE_VALID);
                        break;
                case UNMARK_VALID:
                        active_cache[pos]->ce_flags &= ~htons(CE_VALID);
                        break;
                }
                active_cache_changed = 1;
                return 0;
        }
        return -1;
}

static int add_file_to_cache(const char *path)
{
        int size, namelen, option, status;
        struct cache_entry *ce;
        struct stat st;

        status = lstat(path, &st);
        if (status < 0 || S_ISDIR(st.st_mode)) {
                /* When we used to have "path" and now we want to add
                 * "path/file", we need a way to remove "path" before
                 * being able to add "path/file".  However,
                 * "git-update-index --remove path" would not work.
                 * --force-remove can be used but this is more user
                 * friendly, especially since we can do the opposite
                 * case just fine without --force-remove.
                 */
                if (status == 0 || (errno == ENOENT || errno == ENOTDIR)) {
                        if (allow_remove) {
                                if (remove_file_from_cache(path))
                                        return error("%s: cannot remove from the index",
                                                     path);
                                else
                                        return 0;
                        } else if (status < 0) {
                                return error("%s: does not exist and --remove not passed",
                                             path);
                        }
                }
                if (0 == status)
                        return error("%s: is a directory - add files inside instead",
                                     path);
                else
                        return error("lstat(\"%s\"): %s", path,
                                     strerror(errno));
        }

        namelen = strlen(path);
        size = cache_entry_size(namelen);
        ce = xcalloc(1, size);
        memcpy(ce->name, path, namelen);
        ce->ce_flags = htons(namelen);
        fill_stat_cache_info(ce, &st);

        ce->ce_mode = create_ce_mode(st.st_mode);
        if (!trust_executable_bit) {
                /* If there is an existing entry, pick the mode bits
                 * from it.
                 */
                int pos = cache_name_pos(path, namelen);
                if (0 <= pos)
                        ce->ce_mode = active_cache[pos]->ce_mode;
        }

        if (index_path(ce->sha1, path, &st, !info_only))
                return -1;
        option = allow_add ? ADD_CACHE_OK_TO_ADD : 0;
        option |= allow_replace ? ADD_CACHE_OK_TO_REPLACE : 0;
        if (add_cache_entry(ce, option))
                return error("%s: cannot add to the index - missing --add option?",
                             path);
        return 0;
}

/*
 * "refresh" does not calculate a new sha1 file or bring the
 * cache up-to-date for mode/content changes. But what it
 * _does_ do is to "re-match" the stat information of a file
 * with the cache, so that you can refresh the cache for a
 * file that hasn't been changed but where the stat entry is
 * out of date.
 *
 * For example, you'd want to do this after doing a "git-read-tree",
 * to link up the stat cache details with the proper files.
 */
static struct cache_entry *refresh_entry(struct cache_entry *ce, int really)
{
        struct stat st;
        struct cache_entry *updated;
        int changed, size;

        if (lstat(ce->name, &st) < 0)
                return ERR_PTR(-errno);

        changed = ce_match_stat(ce, &st, really);
        if (!changed) {
                if (really && assume_unchanged &&
                    !(ce->ce_flags & htons(CE_VALID)))
                        ; /* mark this one VALID again */
                else
                        return NULL;
        }

        if (ce_modified(ce, &st, really))
                return ERR_PTR(-EINVAL);

        size = ce_size(ce);
        updated = xmalloc(size);
        memcpy(updated, ce, size);
        fill_stat_cache_info(updated, &st);

        /* In this case, if really is not set, we should leave
         * CE_VALID bit alone.  Otherwise, paths marked with
         * --no-assume-unchanged (i.e. things to be edited) will
         * reacquire CE_VALID bit automatically, which is not
         * really what we want.
         */
        if (!really && assume_unchanged && !(ce->ce_flags & htons(CE_VALID)))
                updated->ce_flags &= ~htons(CE_VALID);

        return updated;
}

static int refresh_cache(int really)
{
        int i;
        int has_errors = 0;

        for (i = 0; i < active_nr; i++) {
                struct cache_entry *ce, *new;
                ce = active_cache[i];
                if (ce_stage(ce)) {
                        while ((i < active_nr) &&
                               ! strcmp(active_cache[i]->name, ce->name))
                                i++;
                        i--;
                        if (allow_unmerged)
                                continue;
                        printf("%s: needs merge\n", ce->name);
                        has_errors = 1;
                        continue;
                }

                new = refresh_entry(ce, really);
                if (!new)
                        continue;
                if (IS_ERR(new)) {
                        if (not_new && PTR_ERR(new) == -ENOENT)
                                continue;
                        if (really && PTR_ERR(new) == -EINVAL) {
                                /* If we are doing --really-refresh that
                                 * means the index is not valid anymore.
                                 */
                                ce->ce_flags &= ~htons(CE_VALID);
                                active_cache_changed = 1;
                        }
                        if (quiet)
                                continue;
                        printf("%s: needs update\n", ce->name);
                        has_errors = 1;
                        continue;
                }
                active_cache_changed = 1;
                /* You can NOT just free active_cache[i] here, since it
                 * might not be necessarily malloc()ed but can also come
                 * from mmap(). */
                active_cache[i] = new;
        }
        return has_errors;
}

/*
 * We fundamentally don't like some paths: we don't want
 * dot or dot-dot anywhere, and for obvious reasons don't
 * want to recurse into ".git" either.
 *
 * Also, we don't want double slashes or slashes at the
 * end that can make pathnames ambiguous.
 */
static int verify_dotfile(const char *rest)
{
        /*
         * The first character was '.', but that
         * has already been discarded, we now test
         * the rest.
         */
        switch (*rest) {
        /* "." is not allowed */
        case '\0': case '/':
                return 0;

        /*
         * ".git" followed by  NUL or slash is bad. This
         * shares the path end test with the ".." case.
         */
        case 'g':
                if (rest[1] != 'i')
                        break;
                if (rest[2] != 't')
                        break;
                rest += 2;
        /* fallthrough */
        case '.':
                if (rest[1] == '\0' || rest[1] == '/')
                        return 0;
        }
        return 1;
}

static int verify_path(const char *path)
{
        char c;

        goto inside;
        for (;;) {
                if (!c)
                        return 1;
                if (c == '/') {
inside:
                        c = *path++;
                        switch (c) {
                        default:
                                continue;
                        case '/': case '\0':
                                break;
                        case '.':
                                if (verify_dotfile(path))
                                        continue;
                        }
                        return 0;
                }
                c = *path++;
        }
}

static int add_cacheinfo(unsigned int mode, const unsigned char *sha1,
                         const char *path, int stage)
{
        int size, len, option;
        struct cache_entry *ce;

        if (!verify_path(path))
                return -1;

        len = strlen(path);
        size = cache_entry_size(len);
        ce = xcalloc(1, size);

        memcpy(ce->sha1, sha1, 20);
        memcpy(ce->name, path, len);
        ce->ce_flags = create_ce_flags(len, stage);
        ce->ce_mode = create_ce_mode(mode);
        if (assume_unchanged)
                ce->ce_flags |= htons(CE_VALID);
        option = allow_add ? ADD_CACHE_OK_TO_ADD : 0;
        option |= allow_replace ? ADD_CACHE_OK_TO_REPLACE : 0;
        if (add_cache_entry(ce, option))
                return error("%s: cannot add to the index - missing --add option?",
                             path);
        report("add '%s'", path);
        return 0;
}

static void chmod_path(int flip, const char *path)
{
        int pos;
        struct cache_entry *ce;
        unsigned int mode;

        pos = cache_name_pos(path, strlen(path));
        if (pos < 0)
                goto fail;
        ce = active_cache[pos];
        mode = ntohl(ce->ce_mode);
        if (!S_ISREG(mode))
                goto fail;
        switch (flip) {
        case '+':
                ce->ce_mode |= htonl(0111); break;
        case '-':
                ce->ce_mode &= htonl(~0111); break;
        default:
                goto fail;
        }
        active_cache_changed = 1;
        report("chmod %cx '%s'", flip, path);
        return;
 fail:
        die("git-update-index: cannot chmod %cx '%s'", flip, path);
}

static struct cache_file cache_file;

static void update_one(const char *path, const char *prefix, int prefix_length)
{
        const char *p = prefix_path(prefix, prefix_length, path);
        if (!verify_path(p)) {
                fprintf(stderr, "Ignoring path %s\n", path);
                return;
        }
        if (mark_valid_only) {
                if (mark_valid(p))
                        die("Unable to mark file %s", path);
                return;
        }

        if (force_remove) {
                if (remove_file_from_cache(p))
                        die("git-update-index: unable to remove %s", path);
                report("remove '%s'", path);
                return;
        }
        if (add_file_to_cache(p))
                die("Unable to process file %s", path);
        report("add '%s'", path);
}

static void read_index_info(int line_termination)
{
        struct strbuf buf;
        strbuf_init(&buf);
        while (1) {
                char *ptr, *tab;
                char *path_name;
                unsigned char sha1[20];
                unsigned int mode;
                int stage;

                /* This reads lines formatted in one of three formats:
                 *
                 * (1) mode         SP sha1          TAB path
                 * The first format is what "git-apply --index-info"
                 * reports, and used to reconstruct a partial tree
                 * that is used for phony merge base tree when falling
                 * back on 3-way merge.
                 *
                 * (2) mode SP type SP sha1          TAB path
                 * The second format is to stuff git-ls-tree output
                 * into the index file.
                 * 
                 * (3) mode         SP sha1 SP stage TAB path
                 * This format is to put higher order stages into the
                 * index file and matches git-ls-files --stage output.
                 */
                read_line(&buf, stdin, line_termination);
                if (buf.eof)
                        break;

                mode = strtoul(buf.buf, &ptr, 8);
                if (ptr == buf.buf || *ptr != ' ')
                        goto bad_line;

                tab = strchr(ptr, '\t');
                if (!tab || tab - ptr < 41)
                        goto bad_line;

                if (tab[-2] == ' ' && '0' <= tab[-1] && tab[-1] <= '3') {
                        stage = tab[-1] - '0';
                        ptr = tab + 1; /* point at the head of path */
                        tab = tab - 2; /* point at tail of sha1 */
                }
                else {
                        stage = 0;
                        ptr = tab + 1; /* point at the head of path */
                }

                if (get_sha1_hex(tab - 40, sha1) || tab[-41] != ' ')
                        goto bad_line;

                if (line_termination && ptr[0] == '"')
                        path_name = unquote_c_style(ptr, NULL);
                else
                        path_name = ptr;

                if (!verify_path(path_name)) {
                        fprintf(stderr, "Ignoring path %s\n", path_name);
                        if (path_name != ptr)
                                free(path_name);
                        continue;
                }

                if (!mode) {
                        /* mode == 0 means there is no such path -- remove */
                        if (remove_file_from_cache(path_name))
                                die("git-update-index: unable to remove %s",
                                    ptr);
                }
                else {
                        /* mode ' ' sha1 '\t' name
                         * ptr[-1] points at tab,
                         * ptr[-41] is at the beginning of sha1
                         */
                        ptr[-42] = ptr[-1] = 0;
                        if (add_cacheinfo(mode, sha1, path_name, stage))
                                die("git-update-index: unable to update %s",
                                    path_name);
                }
                if (path_name != ptr)
                        free(path_name);
                continue;

        bad_line:
                die("malformed index info %s", buf.buf);
        }
}

static const char update_index_usage[] =
"git-update-index [-q] [--add] [--replace] [--remove] [--unmerged] [--refresh] [--cacheinfo] [--chmod=(+|-)x] [--info-only] [--force-remove] [--stdin] [--index-info] [--ignore-missing] [-z] [--verbose] [--] <file>...";

static unsigned char head_sha1[20];
static unsigned char merge_head_sha1[20];

static struct cache_entry *read_one_ent(const char *which,
                                        unsigned char *ent, const char *path,
                                        int namelen, int stage)
{
        unsigned mode;
        unsigned char sha1[20];
        int size;
        struct cache_entry *ce;

        if (get_tree_entry(ent, path, sha1, &mode)) {
                error("%s: not in %s branch.", path, which);
                return NULL;
        }
        if (mode == S_IFDIR) {
                error("%s: not a blob in %s branch.", path, which);
                return NULL;
        }
        size = cache_entry_size(namelen);
        ce = xcalloc(1, size);

        memcpy(ce->sha1, sha1, 20);
        memcpy(ce->name, path, namelen);
        ce->ce_flags = create_ce_flags(namelen, stage);
        ce->ce_mode = create_ce_mode(mode);
        return ce;
}

static int unresolve_one(const char *path)
{
        int namelen = strlen(path);
        int pos;
        int ret = 0;
        struct cache_entry *ce_2 = NULL, *ce_3 = NULL;

        /* See if there is such entry in the index. */
        pos = cache_name_pos(path, namelen);
        if (pos < 0) {
                /* If there isn't, either it is unmerged, or
                 * resolved as "removed" by mistake.  We do not
                 * want to do anything in the former case.
                 */
                pos = -pos-1;
                if (pos < active_nr) {
                        struct cache_entry *ce = active_cache[pos];
                        if (ce_namelen(ce) == namelen &&
                            !memcmp(ce->name, path, namelen)) {
                                fprintf(stderr,
                                        "%s: skipping still unmerged path.\n",
                                        path);
                                goto free_return;
                        }
                }
        }

        /* Grab blobs from given path from HEAD and MERGE_HEAD,
         * stuff HEAD version in stage #2,
         * stuff MERGE_HEAD version in stage #3.
         */
        ce_2 = read_one_ent("our", head_sha1, path, namelen, 2);
        ce_3 = read_one_ent("their", merge_head_sha1, path, namelen, 3);

        if (!ce_2 || !ce_3) {
                ret = -1;
                goto free_return;
        }
        if (!memcmp(ce_2->sha1, ce_3->sha1, 20) &&
            ce_2->ce_mode == ce_3->ce_mode) {
                fprintf(stderr, "%s: identical in both, skipping.\n",
                        path);
                goto free_return;
        }

        remove_file_from_cache(path);
        if (add_cache_entry(ce_2, ADD_CACHE_OK_TO_ADD)) {
                error("%s: cannot add our version to the index.", path);
                ret = -1;
                goto free_return;
        }
        if (!add_cache_entry(ce_3, ADD_CACHE_OK_TO_ADD))
                return 0;
        error("%s: cannot add their version to the index.", path);
        ret = -1;
 free_return:
        free(ce_2);
        free(ce_3);
        return ret;
}

static void read_head_pointers(void)
{
        if (read_ref(git_path("HEAD"), head_sha1))
                die("No HEAD -- no initial commit yet?\n");
        if (read_ref(git_path("MERGE_HEAD"), merge_head_sha1)) {
                fprintf(stderr, "Not in the middle of a merge.\n");
                exit(0);
        }
}

static int do_unresolve(int ac, const char **av)
{
        int i;
        int err = 0;

        /* Read HEAD and MERGE_HEAD; if MERGE_HEAD does not exist, we
         * are not doing a merge, so exit with success status.
         */
        read_head_pointers();

        for (i = 1; i < ac; i++) {
                const char *arg = av[i];
                err |= unresolve_one(arg);
        }
        return err;
}

int main(int argc, const char **argv)
{
        int i, newfd, entries, has_errors = 0, line_termination = '\n';
        int allow_options = 1;
        int read_from_stdin = 0;
        const char *prefix = setup_git_directory();
        int prefix_length = prefix ? strlen(prefix) : 0;
        char set_executable_bit = 0;

        git_config(git_default_config);

        newfd = hold_index_file_for_update(&cache_file, get_index_file());
        if (newfd < 0)
                die("unable to create new cachefile");

        entries = read_cache();
        if (entries < 0)
                die("cache corrupted");

        for (i = 1 ; i < argc; i++) {
                const char *path = argv[i];

                if (allow_options && *path == '-') {
                        if (!strcmp(path, "--")) {
                                allow_options = 0;
                                continue;
                        }
                        if (!strcmp(path, "-q")) {
                                quiet = 1;
                                continue;
                        }
                        if (!strcmp(path, "--add")) {
                                allow_add = 1;
                                continue;
                        }
                        if (!strcmp(path, "--replace")) {
                                allow_replace = 1;
                                continue;
                        }
                        if (!strcmp(path, "--remove")) {
                                allow_remove = 1;
                                continue;
                        }
                        if (!strcmp(path, "--unmerged")) {
                                allow_unmerged = 1;
                                continue;
                        }
                        if (!strcmp(path, "--refresh")) {
                                has_errors |= refresh_cache(0);
                                continue;
                        }
                        if (!strcmp(path, "--really-refresh")) {
                                has_errors |= refresh_cache(1);
                                continue;
                        }
                        if (!strcmp(path, "--cacheinfo")) {
                                unsigned char sha1[20];
                                unsigned int mode;

                                if (i+3 >= argc)
                                        die("git-update-index: --cacheinfo <mode> <sha1> <path>");

                                if ((sscanf(argv[i+1], "%o", &mode) != 1) ||
                                    get_sha1_hex(argv[i+2], sha1) ||
                                    add_cacheinfo(mode, sha1, argv[i+3], 0))
                                        die("git-update-index: --cacheinfo"
                                            " cannot add %s", argv[i+3]);
                                i += 3;
                                continue;
                        }
                        if (!strcmp(path, "--chmod=-x") ||
                            !strcmp(path, "--chmod=+x")) {
                                if (argc <= i+1)
                                        die("git-update-index: %s <path>", path);
                                set_executable_bit = path[8];
                                continue;
                        }
                        if (!strcmp(path, "--assume-unchanged")) {
                                mark_valid_only = MARK_VALID;
                                continue;
                        }
                        if (!strcmp(path, "--no-assume-unchanged")) {
                                mark_valid_only = UNMARK_VALID;
                                continue;
                        }
                        if (!strcmp(path, "--info-only")) {
                                info_only = 1;
                                continue;
                        }
                        if (!strcmp(path, "--force-remove")) {
                                force_remove = 1;
                                continue;
                        }
                        if (!strcmp(path, "-z")) {
                                line_termination = 0;
                                continue;
                        }
                        if (!strcmp(path, "--stdin")) {
                                if (i != argc - 1)
                                        die("--stdin must be at the end");
                                read_from_stdin = 1;
                                break;
                        }
                        if (!strcmp(path, "--index-info")) {
                                if (i != argc - 1)
                                        die("--index-info must be at the end");
                                allow_add = allow_replace = allow_remove = 1;
                                read_index_info(line_termination);
                                break;
                        }
                        if (!strcmp(path, "--unresolve")) {
                                has_errors = do_unresolve(argc - i, argv + i);
                                if (has_errors)
                                        active_cache_changed = 0;
                                goto finish;
                        }
                        if (!strcmp(path, "--ignore-missing")) {
                                not_new = 1;
                                continue;
                        }
                        if (!strcmp(path, "--verbose")) {
                                verbose = 1;
                                continue;
                        }
                        if (!strcmp(path, "-h") || !strcmp(path, "--help"))
                                usage(update_index_usage);
                        die("unknown option %s", path);
                }
                update_one(path, prefix, prefix_length);
                if (set_executable_bit)
                        chmod_path(set_executable_bit, path);
        }
        if (read_from_stdin) {
                struct strbuf buf;
                strbuf_init(&buf);
                while (1) {
                        char *path_name;
                        read_line(&buf, stdin, line_termination);
                        if (buf.eof)
                                break;
                        if (line_termination && buf.buf[0] == '"')
                                path_name = unquote_c_style(buf.buf, NULL);
                        else
                                path_name = buf.buf;
                        update_one(path_name, prefix, prefix_length);
                        if (set_executable_bit) {
                                const char *p = prefix_path(prefix, prefix_length, path_name);
                                chmod_path(set_executable_bit, p);
                        }
                        if (path_name != buf.buf)
                                free(path_name);
                }
        }

 finish:
        if (active_cache_changed) {
                if (write_cache(newfd, active_cache, active_nr) ||
                    commit_index_file(&cache_file))
                        die("Unable to write new cachefile");
        }

        return has_errors ? 1 : 0;
}