/* * Builtin "git merge" * * Copyright (c) 2008 Miklos Vajna * * 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" #include "fmt-merge-msg.h" #include "gpg-interface.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] [...]", "git merge [options] HEAD ", "git merge --abort", NULL }; static int show_diffstat = 1, shortlog_len = -1, squash; static int option_commit = 1, allow_fast_forward = 1; static int fast_forward_only, option_edit = -1; static int allow_trivial = 1, have_message; static int overwrite_ignore = 1; static struct strbuf merge_msg = STRBUF_INIT; 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 const char *sign_commit; 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(¬_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(¬_strategies, ent->name, ent->len); } exclude_cmds(&main_cmds, ¬_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 ) 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_BOOL('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), { OPTION_STRING, 'S', "gpg-sign", &sign_commit, "key id", "GPG sign commit", PARSE_OPT_OPTARG, NULL, (intptr_t) "" }, OPT_BOOLEAN(0, "overwrite-ignore", &overwrite_ignore, "update ignored files (default)"), 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); } /* Get the name for the merge commit's message. */ static void merge_name(const char *remote, struct strbuf *msg) { struct commit *remote_head; unsigned char branch_head[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 = get_merge_parent(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/tags/")) { strbuf_addf(msg, "%s\t\ttag '%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 ^^^.. or ~ */ 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 ...~ */ 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 (ref_exists(truname.buf)) { strbuf_addf(msg, "%s\t\tbranch '%s'%s of .\n", sha1_to_hex(remote_head->object.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->object.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) { int status; 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.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; } status = fmt_merge_msg_config(k, v, cb); if (status) return status; status = git_gpg_config(k, v, NULL); if (status) return status; 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 = merge_remote_util(remoteheads->item)->name; 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)); if (overwrite_ignore) { memset(&dir, 0, sizeof(dir)); dir.flags |= DIR_SHOW_IGNORED; setup_standard_excludes(&dir); 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 const char merge_editor_comment[] = N_("Please enter a commit message to explain why this merge is necessary,\n" "especially if it merges an updated upstream into a topic branch.\n" "\n" "Lines starting with '#' will be ignored, and an empty message aborts\n" "the commit.\n"); static void prepare_to_commit(void) { struct strbuf msg = STRBUF_INIT; const char *comment = _(merge_editor_comment); strbuf_addbuf(&msg, &merge_msg); strbuf_addch(&msg, '\n'); if (0 < option_edit) strbuf_add_lines(&msg, "# ", comment, strlen(comment)); 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, sign_commit)) 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, sign_commit)) 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) { unsigned const char *sha1; struct commit *c = j->item; if (c->util && merge_remote_util(c)->obj) { sha1 = merge_remote_util(c)->obj->sha1; } else { sha1 = c->object.sha1; } strbuf_addf(&buf, "%s\n", sha1_to_hex(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, ret = 0; 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; void *branch_to_free; 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 = branch_to_free = resolve_refdup("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 (shortlog_len < 0) shortlog_len = (merge_log_config > 0) ? merge_log_config : 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' */ ret = cmd_reset(nargc, nargv, prefix); goto done; } 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 ', 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) { if (default_to_upstream) argc = setup_with_upstream(&argv); else die(_("No commit specified and merge.defaultToUpstream not set.")); } 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 HEAD ..." 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 commit *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 = get_merge_parent(argv[0]); if (!remote_head) die(_("%s - not something we can merge"), argv[0]); read_empty(remote_head->object.sha1, 0); update_ref("initial pull", "HEAD", remote_head->object.sha1, NULL, 0, DIE_ON_ERR); goto done; } 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. */ for (i = 0; i < argc; i++) merge_name(argv[i], &merge_names); if (!have_message || shortlog_len) { struct fmt_merge_msg_opts opts; memset(&opts, 0, sizeof(opts)); opts.add_title = !have_message; opts.shortlog_len = shortlog_len; fmt_merge_msg(&merge_names, &merge_msg, &opts); 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 commit *commit = get_merge_parent(argv[i]); if (!commit) die(_("%s - not something we can merge"), argv[i]); remotes = &commit_list_insert(commit, remotes)->next; strbuf_addf(&buf, "GITHEAD_%s", sha1_to_hex(commit->object.sha1)); setenv(buf.buf, argv[i], 1); strbuf_reset(&buf); if (!fast_forward_only && merge_remote_util(commit) && merge_remote_util(commit)->obj && merge_remote_util(commit)->obj->type == OBJ_TAG) { if (option_edit < 0) option_edit = 1; allow_fast_forward = 0; } } if (option_edit < 0) option_edit = 0; 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."); goto done; } 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 commit *commit; 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)"); commit = remoteheads->item; if (!commit) { ret = 1; goto done; } if (checkout_fast_forward(head_commit->object.sha1, commit->object.sha1)) { ret = 1; goto done; } finish(head_commit, commit->object.sha1, msg.buf); drop_save(); goto done; } 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)) { ret = merge_trivial(head_commit); goto done; } 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!"); goto done; } } 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) { ret = finish_automerge(head_commit, common, result_tree, wt_strategy); goto done; } /* * 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); ret = 2; goto done; } 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")); else ret = suggest_conflicts(option_renormalize); done: free(branch_to_free); return ret; }