From 1d119cb63e55121673e813b12316de7765fefd92 Mon Sep 17 00:00:00 2001 From: Gerhard Hoffmann Date: Fri, 5 Apr 2024 11:41:26 +0200 Subject: [PATCH] continued merge --- CalculatorCInterface/git_library.cpp | 271 ++++++++++++++++++++++++++- 1 file changed, 270 insertions(+), 1 deletion(-) diff --git a/CalculatorCInterface/git_library.cpp b/CalculatorCInterface/git_library.cpp index eb71961..cb8e3f8 100644 --- a/CalculatorCInterface/git_library.cpp +++ b/CalculatorCInterface/git_library.cpp @@ -340,7 +340,8 @@ on_error: // // git merge // -struct merge_options { const char **heads; +struct merge_options { + const char **heads; size_t heads_count; git_annotated_commit **annotated; @@ -376,6 +377,208 @@ static void parse_options(const char **repo_path, struct merge_options *opts) { #endif } +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 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(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(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(err, "failed to DWIM reference", git_error_last()->message); + + /* Grab a signature */ + check(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(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(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(git_index_write_tree(&tree_oid, index), "failed to write merged tree", NULL); + check(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, parents); + check(err, "failed to create commit", NULL); + + /* We're done merging, cleanup the repository state */ + git_repository_state_cleanup(repo); + +cleanup: + free(parents); + return err; +} + static int merge(git_repository *repo) { struct merge_options opts; git_index *index; @@ -388,6 +591,72 @@ static int merge(git_repository *repo) { merge_options_init(&opts); parse_options(&path, &opts); + 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(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(err, "merge failed", NULL); + } + + /* If we get here, we actually performed the merge above */ + + check(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);