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/*
* Builtin "git merge"
*
* Copyright (c) 2008 Miklos Vajna <vmiklos@frugalware.org>
*
* Based on git-merge.sh by Junio C Hamano.
*/
#include "cache.h"
#include "parse-options.h"
#include "builtin.h"
#include "run-command.h"
#include "diff.h"
#include "refs.h"
#include "commit.h"
#include "diffcore.h"
#include "revision.h"
#include "unpack-trees.h"
#include "cache-tree.h"
#include "dir.h"
#include "utf8.h"
#include "log-tree.h"
#include "color.h"
#include "rerere.h"
#include "help.h"
#include "merge-recursive.h"
#include "resolve-undo.h"
#include "remote.h"
#define DEFAULT_TWOHEAD (1<<0)
#define DEFAULT_OCTOPUS (1<<1)
#define NO_FAST_FORWARD (1<<2)
#define NO_TRIVIAL (1<<3)
struct strategy {
const char *name;
unsigned attr;
};
static const char * const builtin_merge_usage[] = {
"git merge [options] [<commit>...]",
"git merge [options] <msg> HEAD <commit>",
"git merge --abort",
NULL
};
static int show_diffstat = 1, shortlog_len, squash;
static int option_commit = 1, allow_fast_forward = 1;
static int fast_forward_only, option_edit;
static int allow_trivial = 1, have_message;
static struct strbuf merge_msg;
static struct commit_list *remoteheads;
static struct strategy **use_strategies;
static size_t use_strategies_nr, use_strategies_alloc;
static const char **xopts;
static size_t xopts_nr, xopts_alloc;
static const char *branch;
static char *branch_mergeoptions;
static int option_renormalize;
static int verbosity;
static int allow_rerere_auto;
static int abort_current_merge;
static int show_progress = -1;
static int default_to_upstream;
static struct strategy all_strategy[] = {
{ "recursive", DEFAULT_TWOHEAD | NO_TRIVIAL },
{ "octopus", DEFAULT_OCTOPUS },
{ "resolve", 0 },
{ "ours", NO_FAST_FORWARD | NO_TRIVIAL },
{ "subtree", NO_FAST_FORWARD | NO_TRIVIAL },
};
static const char *pull_twohead, *pull_octopus;
static int option_parse_message(const struct option *opt,
const char *arg, int unset)
{
struct strbuf *buf = opt->value;
if (unset)
strbuf_setlen(buf, 0);
else if (arg) {
strbuf_addf(buf, "%s%s", buf->len ? "\n\n" : "", arg);
have_message = 1;
} else
return error(_("switch `m' requires a value"));
return 0;
}
static struct strategy *get_strategy(const char *name)
{
int i;
struct strategy *ret;
static struct cmdnames main_cmds, other_cmds;
static int loaded;
if (!name)
return NULL;
for (i = 0; i < ARRAY_SIZE(all_strategy); i++)
if (!strcmp(name, all_strategy[i].name))
return &all_strategy[i];
if (!loaded) {
struct cmdnames not_strategies;
loaded = 1;
memset(&not_strategies, 0, sizeof(struct cmdnames));
load_command_list("git-merge-", &main_cmds, &other_cmds);
for (i = 0; i < main_cmds.cnt; i++) {
int j, found = 0;
struct cmdname *ent = main_cmds.names[i];
for (j = 0; j < ARRAY_SIZE(all_strategy); j++)
if (!strncmp(ent->name, all_strategy[j].name, ent->len)
&& !all_strategy[j].name[ent->len])
found = 1;
if (!found)
add_cmdname(&not_strategies, ent->name, ent->len);
}
exclude_cmds(&main_cmds, &not_strategies);
}
if (!is_in_cmdlist(&main_cmds, name) && !is_in_cmdlist(&other_cmds, name)) {
fprintf(stderr, _("Could not find merge strategy '%s'.\n"), name);
fprintf(stderr, _("Available strategies are:"));
for (i = 0; i < main_cmds.cnt; i++)
fprintf(stderr, " %s", main_cmds.names[i]->name);
fprintf(stderr, ".\n");
if (other_cmds.cnt) {
fprintf(stderr, _("Available custom strategies are:"));
for (i = 0; i < other_cmds.cnt; i++)
fprintf(stderr, " %s", other_cmds.names[i]->name);
fprintf(stderr, ".\n");
}
exit(1);
}
ret = xcalloc(1, sizeof(struct strategy));
ret->name = xstrdup(name);
ret->attr = NO_TRIVIAL;
return ret;
}
static void append_strategy(struct strategy *s)
{
ALLOC_GROW(use_strategies, use_strategies_nr + 1, use_strategies_alloc);
use_strategies[use_strategies_nr++] = s;
}
static int option_parse_strategy(const struct option *opt,
const char *name, int unset)
{
if (unset)
return 0;
append_strategy(get_strategy(name));
return 0;
}
static int option_parse_x(const struct option *opt,
const char *arg, int unset)
{
if (unset)
return 0;
ALLOC_GROW(xopts, xopts_nr + 1, xopts_alloc);
xopts[xopts_nr++] = xstrdup(arg);
return 0;
}
static int option_parse_n(const struct option *opt,
const char *arg, int unset)
{
show_diffstat = unset;
return 0;
}
static struct option builtin_merge_options[] = {
{ OPTION_CALLBACK, 'n', NULL, NULL, NULL,
"do not show a diffstat at the end of the merge",
PARSE_OPT_NOARG, option_parse_n },
OPT_BOOLEAN(0, "stat", &show_diffstat,
"show a diffstat at the end of the merge"),
OPT_BOOLEAN(0, "summary", &show_diffstat, "(synonym to --stat)"),
{ OPTION_INTEGER, 0, "log", &shortlog_len, "n",
"add (at most <n>) entries from shortlog to merge commit message",
PARSE_OPT_OPTARG, NULL, DEFAULT_MERGE_LOG_LEN },
OPT_BOOLEAN(0, "squash", &squash,
"create a single commit instead of doing a merge"),
OPT_BOOLEAN(0, "commit", &option_commit,
"perform a commit if the merge succeeds (default)"),
OPT_BOOLEAN('e', "edit", &option_edit,
"edit message before committing"),
OPT_BOOLEAN(0, "ff", &allow_fast_forward,
"allow fast-forward (default)"),
OPT_BOOLEAN(0, "ff-only", &fast_forward_only,
"abort if fast-forward is not possible"),
OPT_RERERE_AUTOUPDATE(&allow_rerere_auto),
OPT_CALLBACK('s', "strategy", &use_strategies, "strategy",
"merge strategy to use", option_parse_strategy),
OPT_CALLBACK('X', "strategy-option", &xopts, "option=value",
"option for selected merge strategy", option_parse_x),
OPT_CALLBACK('m', "message", &merge_msg, "message",
"merge commit message (for a non-fast-forward merge)",
option_parse_message),
OPT__VERBOSITY(&verbosity),
OPT_BOOLEAN(0, "abort", &abort_current_merge,
"abort the current in-progress merge"),
OPT_SET_INT(0, "progress", &show_progress, "force progress reporting", 1),
OPT_END()
};
/* Cleans up metadata that is uninteresting after a succeeded merge. */
static void drop_save(void)
{
unlink(git_path("MERGE_HEAD"));
unlink(git_path("MERGE_MSG"));
unlink(git_path("MERGE_MODE"));
}
static int save_state(unsigned char *stash)
{
int len;
struct child_process cp;
struct strbuf buffer = STRBUF_INIT;
const char *argv[] = {"stash", "create", NULL};
memset(&cp, 0, sizeof(cp));
cp.argv = argv;
cp.out = -1;
cp.git_cmd = 1;
if (start_command(&cp))
die(_("could not run stash."));
len = strbuf_read(&buffer, cp.out, 1024);
close(cp.out);
if (finish_command(&cp) || len < 0)
die(_("stash failed"));
else if (!len) /* no changes */
return -1;
strbuf_setlen(&buffer, buffer.len-1);
if (get_sha1(buffer.buf, stash))
die(_("not a valid object: %s"), buffer.buf);
return 0;
}
static void read_empty(unsigned const char *sha1, int verbose)
{
int i = 0;
const char *args[7];
args[i++] = "read-tree";
if (verbose)
args[i++] = "-v";
args[i++] = "-m";
args[i++] = "-u";
args[i++] = EMPTY_TREE_SHA1_HEX;
args[i++] = sha1_to_hex(sha1);
args[i] = NULL;
if (run_command_v_opt(args, RUN_GIT_CMD))
die(_("read-tree failed"));
}
static void reset_hard(unsigned const char *sha1, int verbose)
{
int i = 0;
const char *args[6];
args[i++] = "read-tree";
if (verbose)
args[i++] = "-v";
args[i++] = "--reset";
args[i++] = "-u";
args[i++] = sha1_to_hex(sha1);
args[i] = NULL;
if (run_command_v_opt(args, RUN_GIT_CMD))
die(_("read-tree failed"));
}
static void restore_state(const unsigned char *head,
const unsigned char *stash)
{
struct strbuf sb = STRBUF_INIT;
const char *args[] = { "stash", "apply", NULL, NULL };
if (is_null_sha1(stash))
return;
reset_hard(head, 1);
args[2] = sha1_to_hex(stash);
/*
* It is OK to ignore error here, for example when there was
* nothing to restore.
*/
run_command_v_opt(args, RUN_GIT_CMD);
strbuf_release(&sb);
refresh_cache(REFRESH_QUIET);
}
/* This is called when no merge was necessary. */
static void finish_up_to_date(const char *msg)
{
if (verbosity >= 0)
printf("%s%s\n", squash ? _(" (nothing to squash)") : "", msg);
drop_save();
}
static void squash_message(struct commit *commit)
{
struct rev_info rev;
struct strbuf out = STRBUF_INIT;
struct commit_list *j;
const char *filename;
int fd;
struct pretty_print_context ctx = {0};
printf(_("Squash commit -- not updating HEAD\n"));
filename = git_path("SQUASH_MSG");
fd = open(filename, O_WRONLY | O_CREAT, 0666);
if (fd < 0)
die_errno(_("Could not write to '%s'"), filename);
init_revisions(&rev, NULL);
rev.ignore_merges = 1;
rev.commit_format = CMIT_FMT_MEDIUM;
commit->object.flags |= UNINTERESTING;
add_pending_object(&rev, &commit->object, NULL);
for (j = remoteheads; j; j = j->next)
add_pending_object(&rev, &j->item->object, NULL);
setup_revisions(0, NULL, &rev, NULL);
if (prepare_revision_walk(&rev))
die(_("revision walk setup failed"));
ctx.abbrev = rev.abbrev;
ctx.date_mode = rev.date_mode;
ctx.fmt = rev.commit_format;
strbuf_addstr(&out, "Squashed commit of the following:\n");
while ((commit = get_revision(&rev)) != NULL) {
strbuf_addch(&out, '\n');
strbuf_addf(&out, "commit %s\n",
sha1_to_hex(commit->object.sha1));
pretty_print_commit(&ctx, commit, &out);
}
if (write(fd, out.buf, out.len) < 0)
die_errno(_("Writing SQUASH_MSG"));
if (close(fd))
die_errno(_("Finishing SQUASH_MSG"));
strbuf_release(&out);
}
static void finish(struct commit *head_commit,
const unsigned char *new_head, const char *msg)
{
struct strbuf reflog_message = STRBUF_INIT;
const unsigned char *head = head_commit->object.sha1;
if (!msg)
strbuf_addstr(&reflog_message, getenv("GIT_REFLOG_ACTION"));
else {
if (verbosity >= 0)
printf("%s\n", msg);
strbuf_addf(&reflog_message, "%s: %s",
getenv("GIT_REFLOG_ACTION"), msg);
}
if (squash) {
squash_message(head_commit);
} else {
if (verbosity >= 0 && !merge_msg.len)
printf(_("No merge message -- not updating HEAD\n"));
else {
const char *argv_gc_auto[] = { "gc", "--auto", NULL };
update_ref(reflog_message.buf, "HEAD",
new_head, head, 0,
DIE_ON_ERR);
/*
* We ignore errors in 'gc --auto', since the
* user should see them.
*/
run_command_v_opt(argv_gc_auto, RUN_GIT_CMD);
}
}
if (new_head && show_diffstat) {
struct diff_options opts;
diff_setup(&opts);
opts.output_format |=
DIFF_FORMAT_SUMMARY | DIFF_FORMAT_DIFFSTAT;
opts.detect_rename = DIFF_DETECT_RENAME;
if (diff_setup_done(&opts) < 0)
die(_("diff_setup_done failed"));
diff_tree_sha1(head, new_head, "", &opts);
diffcore_std(&opts);
diff_flush(&opts);
}
/* Run a post-merge hook */
run_hook(NULL, "post-merge", squash ? "1" : "0", NULL);
strbuf_release(&reflog_message);
}
static struct object *want_commit(const char *name)
{
struct object *obj;
unsigned char sha1[20];
if (get_sha1(name, sha1))
return NULL;
obj = parse_object(sha1);
return peel_to_type(name, 0, obj, OBJ_COMMIT);
}
/* Get the name for the merge commit's message. */
static void merge_name(const char *remote, struct strbuf *msg)
{
struct object *remote_head;
unsigned char branch_head[20], buf_sha[20];
struct strbuf buf = STRBUF_INIT;
struct strbuf bname = STRBUF_INIT;
const char *ptr;
char *found_ref;
int len, early;
strbuf_branchname(&bname, remote);
remote = bname.buf;
memset(branch_head, 0, sizeof(branch_head));
remote_head = want_commit(remote);
if (!remote_head)
die(_("'%s' does not point to a commit"), remote);
if (dwim_ref(remote, strlen(remote), branch_head, &found_ref) > 0) {
if (!prefixcmp(found_ref, "refs/heads/")) {
strbuf_addf(msg, "%s\t\tbranch '%s' of .\n",
sha1_to_hex(branch_head), remote);
goto cleanup;
}
if (!prefixcmp(found_ref, "refs/remotes/")) {
strbuf_addf(msg, "%s\t\tremote-tracking branch '%s' of .\n",
sha1_to_hex(branch_head), remote);
goto cleanup;
}
}
/* See if remote matches <name>^^^.. or <name>~<number> */
for (len = 0, ptr = remote + strlen(remote);
remote < ptr && ptr[-1] == '^';
ptr--)
len++;
if (len)
early = 1;
else {
early = 0;
ptr = strrchr(remote, '~');
if (ptr) {
int seen_nonzero = 0;
len++; /* count ~ */
while (*++ptr && isdigit(*ptr)) {
seen_nonzero |= (*ptr != '0');
len++;
}
if (*ptr)
len = 0; /* not ...~<number> */
else if (seen_nonzero)
early = 1;
else if (len == 1)
early = 1; /* "name~" is "name~1"! */
}
}
if (len) {
struct strbuf truname = STRBUF_INIT;
strbuf_addstr(&truname, "refs/heads/");
strbuf_addstr(&truname, remote);
strbuf_setlen(&truname, truname.len - len);
if (resolve_ref(truname.buf, buf_sha, 1, NULL)) {
strbuf_addf(msg,
"%s\t\tbranch '%s'%s of .\n",
sha1_to_hex(remote_head->sha1),
truname.buf + 11,
(early ? " (early part)" : ""));
strbuf_release(&truname);
goto cleanup;
}
}
if (!strcmp(remote, "FETCH_HEAD") &&
!access(git_path("FETCH_HEAD"), R_OK)) {
const char *filename;
FILE *fp;
struct strbuf line = STRBUF_INIT;
char *ptr;
filename = git_path("FETCH_HEAD");
fp = fopen(filename, "r");
if (!fp)
die_errno(_("could not open '%s' for reading"),
filename);
strbuf_getline(&line, fp, '\n');
fclose(fp);
ptr = strstr(line.buf, "\tnot-for-merge\t");
if (ptr)
strbuf_remove(&line, ptr-line.buf+1, 13);
strbuf_addbuf(msg, &line);
strbuf_release(&line);
goto cleanup;
}
strbuf_addf(msg, "%s\t\tcommit '%s'\n",
sha1_to_hex(remote_head->sha1), remote);
cleanup:
strbuf_release(&buf);
strbuf_release(&bname);
}
static void parse_branch_merge_options(char *bmo)
{
const char **argv;
int argc;
if (!bmo)
return;
argc = split_cmdline(bmo, &argv);
if (argc < 0)
die(_("Bad branch.%s.mergeoptions string: %s"), branch,
split_cmdline_strerror(argc));
argv = xrealloc(argv, sizeof(*argv) * (argc + 2));
memmove(argv + 1, argv, sizeof(*argv) * (argc + 1));
argc++;
argv[0] = "branch.*.mergeoptions";
parse_options(argc, argv, NULL, builtin_merge_options,
builtin_merge_usage, 0);
free(argv);
}
static int git_merge_config(const char *k, const char *v, void *cb)
{
if (branch && !prefixcmp(k, "branch.") &&
!prefixcmp(k + 7, branch) &&
!strcmp(k + 7 + strlen(branch), ".mergeoptions")) {
free(branch_mergeoptions);
branch_mergeoptions = xstrdup(v);
return 0;
}
if (!strcmp(k, "merge.diffstat") || !strcmp(k, "merge.stat"))
show_diffstat = git_config_bool(k, v);
else if (!strcmp(k, "pull.twohead"))
return git_config_string(&pull_twohead, k, v);
else if (!strcmp(k, "pull.octopus"))
return git_config_string(&pull_octopus, k, v);
else if (!strcmp(k, "merge.renormalize"))
option_renormalize = git_config_bool(k, v);
else if (!strcmp(k, "merge.log") || !strcmp(k, "merge.summary")) {
int is_bool;
shortlog_len = git_config_bool_or_int(k, v, &is_bool);
if (!is_bool && shortlog_len < 0)
return error(_("%s: negative length %s"), k, v);
if (is_bool && shortlog_len)
shortlog_len = DEFAULT_MERGE_LOG_LEN;
return 0;
} else if (!strcmp(k, "merge.ff")) {
int boolval = git_config_maybe_bool(k, v);
if (0 <= boolval) {
allow_fast_forward = boolval;
} else if (v && !strcmp(v, "only")) {
allow_fast_forward = 1;
fast_forward_only = 1;
} /* do not barf on values from future versions of git */
return 0;
} else if (!strcmp(k, "merge.defaulttoupstream")) {
default_to_upstream = git_config_bool(k, v);
return 0;
}
return git_diff_ui_config(k, v, cb);
}
static int read_tree_trivial(unsigned char *common, unsigned char *head,
unsigned char *one)
{
int i, nr_trees = 0;
struct tree *trees[MAX_UNPACK_TREES];
struct tree_desc t[MAX_UNPACK_TREES];
struct unpack_trees_options opts;
memset(&opts, 0, sizeof(opts));
opts.head_idx = 2;
opts.src_index = &the_index;
opts.dst_index = &the_index;
opts.update = 1;
opts.verbose_update = 1;
opts.trivial_merges_only = 1;
opts.merge = 1;
trees[nr_trees] = parse_tree_indirect(common);
if (!trees[nr_trees++])
return -1;
trees[nr_trees] = parse_tree_indirect(head);
if (!trees[nr_trees++])
return -1;
trees[nr_trees] = parse_tree_indirect(one);
if (!trees[nr_trees++])
return -1;
opts.fn = threeway_merge;
cache_tree_free(&active_cache_tree);
for (i = 0; i < nr_trees; i++) {
parse_tree(trees[i]);
init_tree_desc(t+i, trees[i]->buffer, trees[i]->size);
}
if (unpack_trees(nr_trees, t, &opts))
return -1;
return 0;
}
static void write_tree_trivial(unsigned char *sha1)
{
if (write_cache_as_tree(sha1, 0, NULL))
die(_("git write-tree failed to write a tree"));
}
static const char *merge_argument(struct commit *commit)
{
if (commit)
return sha1_to_hex(commit->object.sha1);
else
return EMPTY_TREE_SHA1_HEX;
}
int try_merge_command(const char *strategy, size_t xopts_nr,
const char **xopts, struct commit_list *common,
const char *head_arg, struct commit_list *remotes)
{
const char **args;
int i = 0, x = 0, ret;
struct commit_list *j;
struct strbuf buf = STRBUF_INIT;
args = xmalloc((4 + xopts_nr + commit_list_count(common) +
commit_list_count(remotes)) * sizeof(char *));
strbuf_addf(&buf, "merge-%s", strategy);
args[i++] = buf.buf;
for (x = 0; x < xopts_nr; x++) {
char *s = xmalloc(strlen(xopts[x])+2+1);
strcpy(s, "--");
strcpy(s+2, xopts[x]);
args[i++] = s;
}
for (j = common; j; j = j->next)
args[i++] = xstrdup(merge_argument(j->item));
args[i++] = "--";
args[i++] = head_arg;
for (j = remotes; j; j = j->next)
args[i++] = xstrdup(merge_argument(j->item));
args[i] = NULL;
ret = run_command_v_opt(args, RUN_GIT_CMD);
strbuf_release(&buf);
i = 1;
for (x = 0; x < xopts_nr; x++)
free((void *)args[i++]);
for (j = common; j; j = j->next)
free((void *)args[i++]);
i += 2;
for (j = remotes; j; j = j->next)
free((void *)args[i++]);
free(args);
discard_cache();
if (read_cache() < 0)
die(_("failed to read the cache"));
resolve_undo_clear();
return ret;
}
static int try_merge_strategy(const char *strategy, struct commit_list *common,
struct commit *head, const char *head_arg)
{
int index_fd;
struct lock_file *lock = xcalloc(1, sizeof(struct lock_file));
index_fd = hold_locked_index(lock, 1);
refresh_cache(REFRESH_QUIET);
if (active_cache_changed &&
(write_cache(index_fd, active_cache, active_nr) ||
commit_locked_index(lock)))
return error(_("Unable to write index."));
rollback_lock_file(lock);
if (!strcmp(strategy, "recursive") || !strcmp(strategy, "subtree")) {
int clean, x;
struct commit *result;
struct lock_file *lock = xcalloc(1, sizeof(struct lock_file));
int index_fd;
struct commit_list *reversed = NULL;
struct merge_options o;
struct commit_list *j;
if (remoteheads->next) {
error(_("Not handling anything other than two heads merge."));
return 2;
}
init_merge_options(&o);
if (!strcmp(strategy, "subtree"))
o.subtree_shift = "";
o.renormalize = option_renormalize;
o.show_rename_progress =
show_progress == -1 ? isatty(2) : show_progress;
for (x = 0; x < xopts_nr; x++)
if (parse_merge_opt(&o, xopts[x]))
die(_("Unknown option for merge-recursive: -X%s"), xopts[x]);
o.branch1 = head_arg;
o.branch2 = remoteheads->item->util;
for (j = common; j; j = j->next)
commit_list_insert(j->item, &reversed);
index_fd = hold_locked_index(lock, 1);
clean = merge_recursive(&o, head,
remoteheads->item, reversed, &result);
if (active_cache_changed &&
(write_cache(index_fd, active_cache, active_nr) ||
commit_locked_index(lock)))
die (_("unable to write %s"), get_index_file());
rollback_lock_file(lock);
return clean ? 0 : 1;
} else {
return try_merge_command(strategy, xopts_nr, xopts,
common, head_arg, remoteheads);
}
}
static void count_diff_files(struct diff_queue_struct *q,
struct diff_options *opt, void *data)
{
int *count = data;
(*count) += q->nr;
}
static int count_unmerged_entries(void)
{
int i, ret = 0;
for (i = 0; i < active_nr; i++)
if (ce_stage(active_cache[i]))
ret++;
return ret;
}
int checkout_fast_forward(const unsigned char *head, const unsigned char *remote)
{
struct tree *trees[MAX_UNPACK_TREES];
struct unpack_trees_options opts;
struct tree_desc t[MAX_UNPACK_TREES];
int i, fd, nr_trees = 0;
struct dir_struct dir;
struct lock_file *lock_file = xcalloc(1, sizeof(struct lock_file));
refresh_cache(REFRESH_QUIET);
fd = hold_locked_index(lock_file, 1);
memset(&trees, 0, sizeof(trees));
memset(&opts, 0, sizeof(opts));
memset(&t, 0, sizeof(t));
memset(&dir, 0, sizeof(dir));
dir.flags |= DIR_SHOW_IGNORED;
dir.exclude_per_dir = ".gitignore";
opts.dir = &dir;
opts.head_idx = 1;
opts.src_index = &the_index;
opts.dst_index = &the_index;
opts.update = 1;
opts.verbose_update = 1;
opts.merge = 1;
opts.fn = twoway_merge;
setup_unpack_trees_porcelain(&opts, "merge");
trees[nr_trees] = parse_tree_indirect(head);
if (!trees[nr_trees++])
return -1;
trees[nr_trees] = parse_tree_indirect(remote);
if (!trees[nr_trees++])
return -1;
for (i = 0; i < nr_trees; i++) {
parse_tree(trees[i]);
init_tree_desc(t+i, trees[i]->buffer, trees[i]->size);
}
if (unpack_trees(nr_trees, t, &opts))
return -1;
if (write_cache(fd, active_cache, active_nr) ||
commit_locked_index(lock_file))
die(_("unable to write new index file"));
return 0;
}
static void split_merge_strategies(const char *string, struct strategy **list,
int *nr, int *alloc)
{
char *p, *q, *buf;
if (!string)
return;
buf = xstrdup(string);
q = buf;
for (;;) {
p = strchr(q, ' ');
if (!p) {
ALLOC_GROW(*list, *nr + 1, *alloc);
(*list)[(*nr)++].name = xstrdup(q);
free(buf);
return;
} else {
*p = '\0';
ALLOC_GROW(*list, *nr + 1, *alloc);
(*list)[(*nr)++].name = xstrdup(q);
q = ++p;
}
}
}
static void add_strategies(const char *string, unsigned attr)
{
struct strategy *list = NULL;
int list_alloc = 0, list_nr = 0, i;
memset(&list, 0, sizeof(list));
split_merge_strategies(string, &list, &list_nr, &list_alloc);
if (list) {
for (i = 0; i < list_nr; i++)
append_strategy(get_strategy(list[i].name));
return;
}
for (i = 0; i < ARRAY_SIZE(all_strategy); i++)
if (all_strategy[i].attr & attr)
append_strategy(&all_strategy[i]);
}
static void write_merge_msg(struct strbuf *msg)
{
const char *filename = git_path("MERGE_MSG");
int fd = open(filename, O_WRONLY | O_CREAT, 0666);
if (fd < 0)
die_errno(_("Could not open '%s' for writing"),
filename);
if (write_in_full(fd, msg->buf, msg->len) != msg->len)
die_errno(_("Could not write to '%s'"), filename);
close(fd);
}
static void read_merge_msg(struct strbuf *msg)
{
const char *filename = git_path("MERGE_MSG");
strbuf_reset(msg);
if (strbuf_read_file(msg, filename, 0) < 0)
die_errno(_("Could not read from '%s'"), filename);
}
static void write_merge_state(void);
static void abort_commit(const char *err_msg)
{
if (err_msg)
error("%s", err_msg);
fprintf(stderr,
_("Not committing merge; use 'git commit' to complete the merge.\n"));
write_merge_state();
exit(1);
}
static void prepare_to_commit(void)
{
struct strbuf msg = STRBUF_INIT;
strbuf_addbuf(&msg, &merge_msg);
strbuf_addch(&msg, '\n');
write_merge_msg(&msg);
run_hook(get_index_file(), "prepare-commit-msg",
git_path("MERGE_MSG"), "merge", NULL, NULL);
if (option_edit) {
if (launch_editor(git_path("MERGE_MSG"), NULL, NULL))
abort_commit(NULL);
}
read_merge_msg(&msg);
stripspace(&msg, option_edit);
if (!msg.len)
abort_commit(_("Empty commit message."));
strbuf_release(&merge_msg);
strbuf_addbuf(&merge_msg, &msg);
strbuf_release(&msg);
}
static int merge_trivial(struct commit *head)
{
unsigned char result_tree[20], result_commit[20];
struct commit_list *parent = xmalloc(sizeof(*parent));
write_tree_trivial(result_tree);
printf(_("Wonderful.\n"));
parent->item = head;
parent->next = xmalloc(sizeof(*parent->next));
parent->next->item = remoteheads->item;
parent->next->next = NULL;
prepare_to_commit();
if (commit_tree(&merge_msg, result_tree, parent, result_commit, NULL))
die(_("failed to write commit object"));
finish(head, result_commit, "In-index merge");
drop_save();
return 0;
}
static int finish_automerge(struct commit *head,
struct commit_list *common,
unsigned char *result_tree,
const char *wt_strategy)
{
struct commit_list *parents = NULL, *j;
struct strbuf buf = STRBUF_INIT;
unsigned char result_commit[20];
free_commit_list(common);
if (allow_fast_forward) {
parents = remoteheads;
commit_list_insert(head, &parents);
parents = reduce_heads(parents);
} else {
struct commit_list **pptr = &parents;
pptr = &commit_list_insert(head,
pptr)->next;
for (j = remoteheads; j; j = j->next)
pptr = &commit_list_insert(j->item, pptr)->next;
}
strbuf_addch(&merge_msg, '\n');
prepare_to_commit();
free_commit_list(remoteheads);
if (commit_tree(&merge_msg, result_tree, parents, result_commit, NULL))
die(_("failed to write commit object"));
strbuf_addf(&buf, "Merge made by the '%s' strategy.", wt_strategy);
finish(head, result_commit, buf.buf);
strbuf_release(&buf);
drop_save();
return 0;
}
static int suggest_conflicts(int renormalizing)
{
const char *filename;
FILE *fp;
int pos;
filename = git_path("MERGE_MSG");
fp = fopen(filename, "a");
if (!fp)
die_errno(_("Could not open '%s' for writing"), filename);
fprintf(fp, "\nConflicts:\n");
for (pos = 0; pos < active_nr; pos++) {
struct cache_entry *ce = active_cache[pos];
if (ce_stage(ce)) {
fprintf(fp, "\t%s\n", ce->name);
while (pos + 1 < active_nr &&
!strcmp(ce->name,
active_cache[pos + 1]->name))
pos++;
}
}
fclose(fp);
rerere(allow_rerere_auto);
printf(_("Automatic merge failed; "
"fix conflicts and then commit the result.\n"));
return 1;
}
static struct commit *is_old_style_invocation(int argc, const char **argv,
const unsigned char *head)
{
struct commit *second_token = NULL;
if (argc > 2) {
unsigned char second_sha1[20];
if (get_sha1(argv[1], second_sha1))
return NULL;
second_token = lookup_commit_reference_gently(second_sha1, 0);
if (!second_token)
die(_("'%s' is not a commit"), argv[1]);
if (hashcmp(second_token->object.sha1, head))
return NULL;
}
return second_token;
}
static int evaluate_result(void)
{
int cnt = 0;
struct rev_info rev;
/* Check how many files differ. */
init_revisions(&rev, "");
setup_revisions(0, NULL, &rev, NULL);
rev.diffopt.output_format |=
DIFF_FORMAT_CALLBACK;
rev.diffopt.format_callback = count_diff_files;
rev.diffopt.format_callback_data = &cnt;
run_diff_files(&rev, 0);
/*
* Check how many unmerged entries are
* there.
*/
cnt += count_unmerged_entries();
return cnt;
}
/*
* Pretend as if the user told us to merge with the tracking
* branch we have for the upstream of the current branch
*/
static int setup_with_upstream(const char ***argv)
{
struct branch *branch = branch_get(NULL);
int i;
const char **args;
if (!branch)
die(_("No current branch."));
if (!branch->remote)
die(_("No remote for the current branch."));
if (!branch->merge_nr)
die(_("No default upstream defined for the current branch."));
args = xcalloc(branch->merge_nr + 1, sizeof(char *));
for (i = 0; i < branch->merge_nr; i++) {
if (!branch->merge[i]->dst)
die(_("No remote tracking branch for %s from %s"),
branch->merge[i]->src, branch->remote_name);
args[i] = branch->merge[i]->dst;
}
args[i] = NULL;
*argv = args;
return i;
}
static void write_merge_state(void)
{
const char *filename;
int fd;
struct commit_list *j;
struct strbuf buf = STRBUF_INIT;
for (j = remoteheads; j; j = j->next)
strbuf_addf(&buf, "%s\n",
sha1_to_hex(j->item->object.sha1));
filename = git_path("MERGE_HEAD");
fd = open(filename, O_WRONLY | O_CREAT, 0666);
if (fd < 0)
die_errno(_("Could not open '%s' for writing"), filename);
if (write_in_full(fd, buf.buf, buf.len) != buf.len)
die_errno(_("Could not write to '%s'"), filename);
close(fd);
strbuf_addch(&merge_msg, '\n');
write_merge_msg(&merge_msg);
filename = git_path("MERGE_MODE");
fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC, 0666);
if (fd < 0)
die_errno(_("Could not open '%s' for writing"), filename);
strbuf_reset(&buf);
if (!allow_fast_forward)
strbuf_addf(&buf, "no-ff");
if (write_in_full(fd, buf.buf, buf.len) != buf.len)
die_errno(_("Could not write to '%s'"), filename);
close(fd);
}
int cmd_merge(int argc, const char **argv, const char *prefix)
{
unsigned char result_tree[20];
unsigned char stash[20];
unsigned char head_sha1[20];
struct commit *head_commit;
struct strbuf buf = STRBUF_INIT;
const char *head_arg;
int flag, i;
int best_cnt = -1, merge_was_ok = 0, automerge_was_ok = 0;
struct commit_list *common = NULL;
const char *best_strategy = NULL, *wt_strategy = NULL;
struct commit_list **remotes = &remoteheads;
if (argc == 2 && !strcmp(argv[1], "-h"))
usage_with_options(builtin_merge_usage, builtin_merge_options);
/*
* Check if we are _not_ on a detached HEAD, i.e. if there is a
* current branch.
*/
branch = resolve_ref("HEAD", head_sha1, 0, &flag);
if (branch && !prefixcmp(branch, "refs/heads/"))
branch += 11;
if (!branch || is_null_sha1(head_sha1))
head_commit = NULL;
else
head_commit = lookup_commit_or_die(head_sha1, "HEAD");
git_config(git_merge_config, NULL);
if (branch_mergeoptions)
parse_branch_merge_options(branch_mergeoptions);
argc = parse_options(argc, argv, prefix, builtin_merge_options,
builtin_merge_usage, 0);
if (verbosity < 0 && show_progress == -1)
show_progress = 0;
if (abort_current_merge) {
int nargc = 2;
const char *nargv[] = {"reset", "--merge", NULL};
if (!file_exists(git_path("MERGE_HEAD")))
die(_("There is no merge to abort (MERGE_HEAD missing)."));
/* Invoke 'git reset --merge' */
return cmd_reset(nargc, nargv, prefix);
}
if (read_cache_unmerged())
die_resolve_conflict("merge");
if (file_exists(git_path("MERGE_HEAD"))) {
/*
* There is no unmerged entry, don't advise 'git
* add/rm <file>', just 'git commit'.
*/
if (advice_resolve_conflict)
die(_("You have not concluded your merge (MERGE_HEAD exists).\n"
"Please, commit your changes before you can merge."));
else
die(_("You have not concluded your merge (MERGE_HEAD exists)."));
}
if (file_exists(git_path("CHERRY_PICK_HEAD"))) {
if (advice_resolve_conflict)
die(_("You have not concluded your cherry-pick (CHERRY_PICK_HEAD exists).\n"
"Please, commit your changes before you can merge."));
else
die(_("You have not concluded your cherry-pick (CHERRY_PICK_HEAD exists)."));
}
resolve_undo_clear();
if (verbosity < 0)
show_diffstat = 0;
if (squash) {
if (!allow_fast_forward)
die(_("You cannot combine --squash with --no-ff."));
option_commit = 0;
}
if (!allow_fast_forward && fast_forward_only)
die(_("You cannot combine --no-ff with --ff-only."));
if (!abort_current_merge) {
if (!argc && default_to_upstream)
argc = setup_with_upstream(&argv);
else if (argc == 1 && !strcmp(argv[0], "-"))
argv[0] = "@{-1}";
}
if (!argc)
usage_with_options(builtin_merge_usage,
builtin_merge_options);
/*
* This could be traditional "merge <msg> HEAD <commit>..." and
* the way we can tell it is to see if the second token is HEAD,
* but some people might have misused the interface and used a
* committish that is the same as HEAD there instead.
* Traditional format never would have "-m" so it is an
* additional safety measure to check for it.
*/
if (!have_message && head_commit &&
is_old_style_invocation(argc, argv, head_commit->object.sha1)) {
strbuf_addstr(&merge_msg, argv[0]);
head_arg = argv[1];
argv += 2;
argc -= 2;
} else if (!head_commit) {
struct object *remote_head;
/*
* If the merged head is a valid one there is no reason
* to forbid "git merge" into a branch yet to be born.
* We do the same for "git pull".
*/
if (argc != 1)
die(_("Can merge only exactly one commit into "
"empty head"));
if (squash)
die(_("Squash commit into empty head not supported yet"));
if (!allow_fast_forward)
die(_("Non-fast-forward commit does not make sense into "
"an empty head"));
remote_head = want_commit(argv[0]);
if (!remote_head)
die(_("%s - not something we can merge"), argv[0]);
read_empty(remote_head->sha1, 0);
update_ref("initial pull", "HEAD", remote_head->sha1, NULL, 0,
DIE_ON_ERR);
return 0;
} else {
struct strbuf merge_names = STRBUF_INIT;
/* We are invoked directly as the first-class UI. */
head_arg = "HEAD";
/*
* All the rest are the commits being merged;
* prepare the standard merge summary message to
* be appended to the given message. If remote
* is invalid we will die later in the common
* codepath so we discard the error in this
* loop.
*/
for (i = 0; i < argc; i++)
merge_name(argv[i], &merge_names);
if (!have_message || shortlog_len) {
fmt_merge_msg(&merge_names, &merge_msg, !have_message,
shortlog_len);
if (merge_msg.len)
strbuf_setlen(&merge_msg, merge_msg.len - 1);
}
}
if (!head_commit || !argc)
usage_with_options(builtin_merge_usage,
builtin_merge_options);
strbuf_addstr(&buf, "merge");
for (i = 0; i < argc; i++)
strbuf_addf(&buf, " %s", argv[i]);
setenv("GIT_REFLOG_ACTION", buf.buf, 0);
strbuf_reset(&buf);
for (i = 0; i < argc; i++) {
struct object *o;
struct commit *commit;
o = want_commit(argv[i]);
if (!o)
die(_("%s - not something we can merge"), argv[i]);
commit = lookup_commit(o->sha1);
commit->util = (void *)argv[i];
remotes = &commit_list_insert(commit, remotes)->next;
strbuf_addf(&buf, "GITHEAD_%s", sha1_to_hex(o->sha1));
setenv(buf.buf, argv[i], 1);
strbuf_reset(&buf);
}
if (!use_strategies) {
if (!remoteheads->next)
add_strategies(pull_twohead, DEFAULT_TWOHEAD);
else
add_strategies(pull_octopus, DEFAULT_OCTOPUS);
}
for (i = 0; i < use_strategies_nr; i++) {
if (use_strategies[i]->attr & NO_FAST_FORWARD)
allow_fast_forward = 0;
if (use_strategies[i]->attr & NO_TRIVIAL)
allow_trivial = 0;
}
if (!remoteheads->next)
common = get_merge_bases(head_commit, remoteheads->item, 1);
else {
struct commit_list *list = remoteheads;
commit_list_insert(head_commit, &list);
common = get_octopus_merge_bases(list);
free(list);
}
update_ref("updating ORIG_HEAD", "ORIG_HEAD", head_commit->object.sha1,
NULL, 0, DIE_ON_ERR);
if (!common)
; /* No common ancestors found. We need a real merge. */
else if (!remoteheads->next && !common->next &&
common->item == remoteheads->item) {
/*
* If head can reach all the merge then we are up to date.
* but first the most common case of merging one remote.
*/
finish_up_to_date("Already up-to-date.");
return 0;
} else if (allow_fast_forward && !remoteheads->next &&
!common->next &&
!hashcmp(common->item->object.sha1, head_commit->object.sha1)) {
/* Again the most common case of merging one remote. */
struct strbuf msg = STRBUF_INIT;
struct object *o;
char hex[41];
strcpy(hex, find_unique_abbrev(head_commit->object.sha1, DEFAULT_ABBREV));
if (verbosity >= 0)
printf(_("Updating %s..%s\n"),
hex,
find_unique_abbrev(remoteheads->item->object.sha1,
DEFAULT_ABBREV));
strbuf_addstr(&msg, "Fast-forward");
if (have_message)
strbuf_addstr(&msg,
" (no commit created; -m option ignored)");
o = want_commit(sha1_to_hex(remoteheads->item->object.sha1));
if (!o)
return 1;
if (checkout_fast_forward(head_commit->object.sha1, remoteheads->item->object.sha1))
return 1;
finish(head_commit, o->sha1, msg.buf);
drop_save();
return 0;
} else if (!remoteheads->next && common->next)
;
/*
* We are not doing octopus and not fast-forward. Need
* a real merge.
*/
else if (!remoteheads->next && !common->next && option_commit) {
/*
* We are not doing octopus, not fast-forward, and have
* only one common.
*/
refresh_cache(REFRESH_QUIET);
if (allow_trivial && !fast_forward_only) {
/* See if it is really trivial. */
git_committer_info(IDENT_ERROR_ON_NO_NAME);
printf(_("Trying really trivial in-index merge...\n"));
if (!read_tree_trivial(common->item->object.sha1,
head_commit->object.sha1, remoteheads->item->object.sha1))
return merge_trivial(head_commit);
printf(_("Nope.\n"));
}
} else {
/*
* An octopus. If we can reach all the remote we are up
* to date.
*/
int up_to_date = 1;
struct commit_list *j;
for (j = remoteheads; j; j = j->next) {
struct commit_list *common_one;
/*
* Here we *have* to calculate the individual
* merge_bases again, otherwise "git merge HEAD^
* HEAD^^" would be missed.
*/
common_one = get_merge_bases(head_commit, j->item, 1);
if (hashcmp(common_one->item->object.sha1,
j->item->object.sha1)) {
up_to_date = 0;
break;
}
}
if (up_to_date) {
finish_up_to_date("Already up-to-date. Yeeah!");
return 0;
}
}
if (fast_forward_only)
die(_("Not possible to fast-forward, aborting."));
/* We are going to make a new commit. */
git_committer_info(IDENT_ERROR_ON_NO_NAME);
/*
* At this point, we need a real merge. No matter what strategy
* we use, it would operate on the index, possibly affecting the
* working tree, and when resolved cleanly, have the desired
* tree in the index -- this means that the index must be in
* sync with the head commit. The strategies are responsible
* to ensure this.
*/
if (use_strategies_nr == 1 ||
/*
* Stash away the local changes so that we can try more than one.
*/
save_state(stash))
hashcpy(stash, null_sha1);
for (i = 0; i < use_strategies_nr; i++) {
int ret;
if (i) {
printf(_("Rewinding the tree to pristine...\n"));
restore_state(head_commit->object.sha1, stash);
}
if (use_strategies_nr != 1)
printf(_("Trying merge strategy %s...\n"),
use_strategies[i]->name);
/*
* Remember which strategy left the state in the working
* tree.
*/
wt_strategy = use_strategies[i]->name;
ret = try_merge_strategy(use_strategies[i]->name,
common, head_commit, head_arg);
if (!option_commit && !ret) {
merge_was_ok = 1;
/*
* This is necessary here just to avoid writing
* the tree, but later we will *not* exit with
* status code 1 because merge_was_ok is set.
*/
ret = 1;
}
if (ret) {
/*
* The backend exits with 1 when conflicts are
* left to be resolved, with 2 when it does not
* handle the given merge at all.
*/
if (ret == 1) {
int cnt = evaluate_result();
if (best_cnt <= 0 || cnt <= best_cnt) {
best_strategy = use_strategies[i]->name;
best_cnt = cnt;
}
}
if (merge_was_ok)
break;
else
continue;
}
/* Automerge succeeded. */
write_tree_trivial(result_tree);
automerge_was_ok = 1;
break;
}
/*
* If we have a resulting tree, that means the strategy module
* auto resolved the merge cleanly.
*/
if (automerge_was_ok)
return finish_automerge(head_commit, common, result_tree,
wt_strategy);
/*
* Pick the result from the best strategy and have the user fix
* it up.
*/
if (!best_strategy) {
restore_state(head_commit->object.sha1, stash);
if (use_strategies_nr > 1)
fprintf(stderr,
_("No merge strategy handled the merge.\n"));
else
fprintf(stderr, _("Merge with strategy %s failed.\n"),
use_strategies[0]->name);
return 2;
} else if (best_strategy == wt_strategy)
; /* We already have its result in the working tree. */
else {
printf(_("Rewinding the tree to pristine...\n"));
restore_state(head_commit->object.sha1, stash);
printf(_("Using the %s to prepare resolving by hand.\n"),
best_strategy);
try_merge_strategy(best_strategy, common, head_commit, head_arg);
}
if (squash)
finish(head_commit, NULL, NULL);
else
write_merge_state();
if (merge_was_ok) {
fprintf(stderr, _("Automatic merge went well; "
"stopped before committing as requested\n"));
return 0;
} else
return suggest_conflicts(option_renormalize);
}
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