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-rw-r--r--examples/merge.c361
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diff --git a/examples/merge.c b/examples/merge.c
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+/*
+ * libgit2 "merge" example - shows how to perform merges
+ *
+ * Written by the libgit2 contributors
+ *
+ * To the extent possible under law, the author(s) have dedicated all copyright
+ * and related and neighboring rights to this software to the public domain
+ * worldwide. This software is distributed without any warranty.
+ *
+ * You should have received a copy of the CC0 Public Domain Dedication along
+ * with this software. If not, see
+ * <http://creativecommons.org/publicdomain/zero/1.0/>.
+ */
+
+#include "common.h"
+
+/** The following example demonstrates how to do merges with libgit2.
+ *
+ * It will merge whatever commit-ish you pass in into the current branch.
+ *
+ * Recognized options are :
+ * --no-commit: don't actually commit the merge.
+ *
+ */
+
+struct merge_options {
+ const char **heads;
+ size_t heads_count;
+
+ git_annotated_commit **annotated;
+ size_t annotated_count;
+
+ int no_commit : 1;
+};
+
+static void print_usage(void)
+{
+ fprintf(stderr, "usage: merge [--no-commit] <commit...>\n");
+ exit(1);
+}
+
+static void merge_options_init(struct merge_options *opts)
+{
+ memset(opts, 0, sizeof(*opts));
+
+ opts->heads = NULL;
+ opts->heads_count = 0;
+ opts->annotated = NULL;
+ opts->annotated_count = 0;
+}
+
+static void opts_add_refish(struct merge_options *opts, const char *refish)
+{
+ size_t sz;
+
+ assert(opts != NULL);
+
+ sz = ++opts->heads_count * sizeof(opts->heads[0]);
+ opts->heads = xrealloc((void *) opts->heads, sz);
+ opts->heads[opts->heads_count - 1] = refish;
+}
+
+static void parse_options(const char **repo_path, struct merge_options *opts, int argc, char **argv)
+{
+ struct args_info args = ARGS_INFO_INIT;
+
+ if (argc <= 1)
+ print_usage();
+
+ for (args.pos = 1; args.pos < argc; ++args.pos) {
+ const char *curr = argv[args.pos];
+
+ if (curr[0] != '-') {
+ opts_add_refish(opts, curr);
+ } else if (!strcmp(curr, "--no-commit")) {
+ opts->no_commit = 1;
+ } else if (match_str_arg(repo_path, &args, "--git-dir")) {
+ continue;
+ } else {
+ print_usage();
+ }
+ }
+}
+
+static int resolve_heads(git_repository *repo, struct merge_options *opts)
+{
+ git_annotated_commit **annotated = calloc(opts->heads_count, sizeof(git_annotated_commit *));
+ size_t annotated_count = 0, i;
+ int err = 0;
+
+ for (i = 0; i < opts->heads_count; i++) {
+ err = resolve_refish(&annotated[annotated_count++], repo, opts->heads[i]);
+ if (err != 0) {
+ fprintf(stderr, "failed to resolve refish %s: %s\n", opts->heads[i], git_error_last()->message);
+ annotated_count--;
+ continue;
+ }
+ }
+
+ if (annotated_count != opts->heads_count) {
+ fprintf(stderr, "unable to parse some refish\n");
+ free(annotated);
+ return -1;
+ }
+
+ opts->annotated = annotated;
+ opts->annotated_count = annotated_count;
+ return 0;
+}
+
+static int perform_fastforward(git_repository *repo, const git_oid *target_oid, int is_unborn)
+{
+ git_checkout_options ff_checkout_options = GIT_CHECKOUT_OPTIONS_INIT;
+ git_reference *target_ref;
+ git_reference *new_target_ref;
+ git_object *target = NULL;
+ int err = 0;
+
+ if (is_unborn) {
+ const char *symbolic_ref;
+ git_reference *head_ref;
+
+ /* HEAD reference is unborn, lookup manually so we don't try to resolve it */
+ err = git_reference_lookup(&head_ref, repo, "HEAD");
+ if (err != 0) {
+ fprintf(stderr, "failed to lookup HEAD ref\n");
+ return -1;
+ }
+
+ /* Grab the reference HEAD should be pointing to */
+ symbolic_ref = git_reference_symbolic_target(head_ref);
+
+ /* Create our master reference on the target OID */
+ err = git_reference_create(&target_ref, repo, symbolic_ref, target_oid, 0, NULL);
+ if (err != 0) {
+ fprintf(stderr, "failed to create master reference\n");
+ return -1;
+ }
+
+ git_reference_free(head_ref);
+ } else {
+ /* HEAD exists, just lookup and resolve */
+ err = git_repository_head(&target_ref, repo);
+ if (err != 0) {
+ fprintf(stderr, "failed to get HEAD reference\n");
+ return -1;
+ }
+ }
+
+ /* Lookup the target object */
+ err = git_object_lookup(&target, repo, target_oid, GIT_OBJECT_COMMIT);
+ if (err != 0) {
+ fprintf(stderr, "failed to lookup OID %s\n", git_oid_tostr_s(target_oid));
+ return -1;
+ }
+
+ /* Checkout the result so the workdir is in the expected state */
+ ff_checkout_options.checkout_strategy = GIT_CHECKOUT_SAFE;
+ err = git_checkout_tree(repo, target, &ff_checkout_options);
+ if (err != 0) {
+ fprintf(stderr, "failed to checkout HEAD reference\n");
+ return -1;
+ }
+
+ /* Move the target reference to the target OID */
+ err = git_reference_set_target(&new_target_ref, target_ref, target_oid, NULL);
+ if (err != 0) {
+ fprintf(stderr, "failed to move HEAD reference\n");
+ return -1;
+ }
+
+ git_reference_free(target_ref);
+ git_reference_free(new_target_ref);
+ git_object_free(target);
+
+ return 0;
+}
+
+static void output_conflicts(git_index *index)
+{
+ git_index_conflict_iterator *conflicts;
+ const git_index_entry *ancestor;
+ const git_index_entry *our;
+ const git_index_entry *their;
+ int err = 0;
+
+ check_lg2(git_index_conflict_iterator_new(&conflicts, index), "failed to create conflict iterator", NULL);
+
+ while ((err = git_index_conflict_next(&ancestor, &our, &their, conflicts)) == 0) {
+ fprintf(stderr, "conflict: a:%s o:%s t:%s\n",
+ ancestor ? ancestor->path : "NULL",
+ our->path ? our->path : "NULL",
+ their->path ? their->path : "NULL");
+ }
+
+ if (err != GIT_ITEROVER) {
+ fprintf(stderr, "error iterating conflicts\n");
+ }
+
+ git_index_conflict_iterator_free(conflicts);
+}
+
+static int create_merge_commit(git_repository *repo, git_index *index, struct merge_options *opts)
+{
+ git_oid tree_oid, commit_oid;
+ git_tree *tree;
+ git_signature *sign;
+ git_reference *merge_ref = NULL;
+ git_annotated_commit *merge_commit;
+ git_reference *head_ref;
+ git_commit **parents = calloc(opts->annotated_count + 1, sizeof(git_commit *));
+ const char *msg_target = NULL;
+ size_t msglen = 0;
+ char *msg;
+ size_t i;
+ int err;
+
+ /* Grab our needed references */
+ check_lg2(git_repository_head(&head_ref, repo), "failed to get repo HEAD", NULL);
+ if (resolve_refish(&merge_commit, repo, opts->heads[0])) {
+ fprintf(stderr, "failed to resolve refish %s", opts->heads[0]);
+ free(parents);
+ return -1;
+ }
+
+ /* Maybe that's a ref, so DWIM it */
+ err = git_reference_dwim(&merge_ref, repo, opts->heads[0]);
+ check_lg2(err, "failed to DWIM reference", git_error_last()->message);
+
+ /* Grab a signature */
+ check_lg2(git_signature_now(&sign, "Me", "me@example.com"), "failed to create signature", NULL);
+
+#define MERGE_COMMIT_MSG "Merge %s '%s'"
+ /* Prepare a standard merge commit message */
+ if (merge_ref != NULL) {
+ check_lg2(git_branch_name(&msg_target, merge_ref), "failed to get branch name of merged ref", NULL);
+ } else {
+ msg_target = git_oid_tostr_s(git_annotated_commit_id(merge_commit));
+ }
+
+ msglen = snprintf(NULL, 0, MERGE_COMMIT_MSG, (merge_ref ? "branch" : "commit"), msg_target);
+ if (msglen > 0) msglen++;
+ msg = malloc(msglen);
+ err = snprintf(msg, msglen, MERGE_COMMIT_MSG, (merge_ref ? "branch" : "commit"), msg_target);
+
+ /* This is only to silence the compiler */
+ if (err < 0) goto cleanup;
+
+ /* Setup our parent commits */
+ err = git_reference_peel((git_object **)&parents[0], head_ref, GIT_OBJECT_COMMIT);
+ check_lg2(err, "failed to peel head reference", NULL);
+ for (i = 0; i < opts->annotated_count; i++) {
+ git_commit_lookup(&parents[i + 1], repo, git_annotated_commit_id(opts->annotated[i]));
+ }
+
+ /* Prepare our commit tree */
+ check_lg2(git_index_write_tree(&tree_oid, index), "failed to write merged tree", NULL);
+ check_lg2(git_tree_lookup(&tree, repo, &tree_oid), "failed to lookup tree", NULL);
+
+ /* Commit time ! */
+ err = git_commit_create(&commit_oid,
+ repo, git_reference_name(head_ref),
+ sign, sign,
+ NULL, msg,
+ tree,
+ opts->annotated_count + 1, (const git_commit **)parents);
+ check_lg2(err, "failed to create commit", NULL);
+
+ /* We're done merging, cleanup the repository state */
+ git_repository_state_cleanup(repo);
+
+cleanup:
+ free(parents);
+ return err;
+}
+
+int lg2_merge(git_repository *repo, int argc, char **argv)
+{
+ struct merge_options opts;
+ git_index *index;
+ git_repository_state_t state;
+ git_merge_analysis_t analysis;
+ git_merge_preference_t preference;
+ const char *path = ".";
+ int err = 0;
+
+ merge_options_init(&opts);
+ parse_options(&path, &opts, argc, argv);
+
+ state = git_repository_state(repo);
+ if (state != GIT_REPOSITORY_STATE_NONE) {
+ fprintf(stderr, "repository is in unexpected state %d\n", state);
+ goto cleanup;
+ }
+
+ err = resolve_heads(repo, &opts);
+ if (err != 0)
+ goto cleanup;
+
+ err = git_merge_analysis(&analysis, &preference,
+ repo,
+ (const git_annotated_commit **)opts.annotated,
+ opts.annotated_count);
+ check_lg2(err, "merge analysis failed", NULL);
+
+ if (analysis & GIT_MERGE_ANALYSIS_UP_TO_DATE) {
+ printf("Already up-to-date\n");
+ return 0;
+ } else if (analysis & GIT_MERGE_ANALYSIS_UNBORN ||
+ (analysis & GIT_MERGE_ANALYSIS_FASTFORWARD &&
+ !(preference & GIT_MERGE_PREFERENCE_NO_FASTFORWARD))) {
+ const git_oid *target_oid;
+ if (analysis & GIT_MERGE_ANALYSIS_UNBORN) {
+ printf("Unborn\n");
+ } else {
+ printf("Fast-forward\n");
+ }
+
+ /* Since this is a fast-forward, there can be only one merge head */
+ target_oid = git_annotated_commit_id(opts.annotated[0]);
+ assert(opts.annotated_count == 1);
+
+ return perform_fastforward(repo, target_oid, (analysis & GIT_MERGE_ANALYSIS_UNBORN));
+ } else if (analysis & GIT_MERGE_ANALYSIS_NORMAL) {
+ git_merge_options merge_opts = GIT_MERGE_OPTIONS_INIT;
+ git_checkout_options checkout_opts = GIT_CHECKOUT_OPTIONS_INIT;
+
+ merge_opts.flags = 0;
+ merge_opts.file_flags = GIT_MERGE_FILE_STYLE_DIFF3;
+
+ checkout_opts.checkout_strategy = GIT_CHECKOUT_FORCE|GIT_CHECKOUT_ALLOW_CONFLICTS;
+
+ if (preference & GIT_MERGE_PREFERENCE_FASTFORWARD_ONLY) {
+ printf("Fast-forward is preferred, but only a merge is possible\n");
+ return -1;
+ }
+
+ err = git_merge(repo,
+ (const git_annotated_commit **)opts.annotated, opts.annotated_count,
+ &merge_opts, &checkout_opts);
+ check_lg2(err, "merge failed", NULL);
+ }
+
+ /* If we get here, we actually performed the merge above */
+
+ check_lg2(git_repository_index(&index, repo), "failed to get repository index", NULL);
+
+ if (git_index_has_conflicts(index)) {
+ /* Handle conflicts */
+ output_conflicts(index);
+ } else if (!opts.no_commit) {
+ create_merge_commit(repo, index, &opts);
+ printf("Merge made\n");
+ }
+
+cleanup:
+ free((char **)opts.heads);
+ free(opts.annotated);
+
+ return 0;
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-01 18:26:37 +0000