#include "cache.h"
#include "merge-ort.h"
+#include "alloc.h"
+#include "blob.h"
+#include "cache-tree.h"
+#include "commit.h"
+#include "commit-reach.h"
+#include "diff.h"
+#include "diffcore.h"
+#include "dir.h"
+#include "ll-merge.h"
+#include "object-store.h"
+#include "revision.h"
+#include "strmap.h"
+#include "submodule.h"
+#include "tree.h"
+#include "unpack-trees.h"
+#include "xdiff-interface.h"
+
+/*
+ * We have many arrays of size 3. Whenever we have such an array, the
+ * indices refer to one of the sides of the three-way merge. This is so
+ * pervasive that the constants 0, 1, and 2 are used in many places in the
+ * code (especially in arithmetic operations to find the other side's index
+ * or to compute a relevant mask), but sometimes these enum names are used
+ * to aid code clarity.
+ *
+ * See also 'filemask' and 'dirmask' in struct conflict_info; the "ith side"
+ * referred to there is one of these three sides.
+ */
+enum merge_side {
+ MERGE_BASE = 0,
+ MERGE_SIDE1 = 1,
+ MERGE_SIDE2 = 2
+};
+
+struct rename_info {
+ /*
+ * pairs: pairing of filenames from diffcore_rename()
+ *
+ * Index 1 and 2 correspond to sides 1 & 2 as used in
+ * conflict_info.stages. Index 0 unused.
+ */
+ struct diff_queue_struct pairs[3];
+
+ /*
+ * needed_limit: value needed for inexact rename detection to run
+ *
+ * If the current rename limit wasn't high enough for inexact
+ * rename detection to run, this records the limit needed. Otherwise,
+ * this value remains 0.
+ */
+ int needed_limit;
+};
+
+struct merge_options_internal {
+ /*
+ * paths: primary data structure in all of merge ort.
+ *
+ * The keys of paths:
+ * * are full relative paths from the toplevel of the repository
+ * (e.g. "drivers/firmware/raspberrypi.c").
+ * * store all relevant paths in the repo, both directories and
+ * files (e.g. drivers, drivers/firmware would also be included)
+ * * these keys serve to intern all the path strings, which allows
+ * us to do pointer comparison on directory names instead of
+ * strcmp; we just have to be careful to use the interned strings.
+ * (Technically paths_to_free may track some strings that were
+ * removed from froms paths.)
+ *
+ * The values of paths:
+ * * either a pointer to a merged_info, or a conflict_info struct
+ * * merged_info contains all relevant information for a
+ * non-conflicted entry.
+ * * conflict_info contains a merged_info, plus any additional
+ * information about a conflict such as the higher orders stages
+ * involved and the names of the paths those came from (handy
+ * once renames get involved).
+ * * a path may start "conflicted" (i.e. point to a conflict_info)
+ * and then a later step (e.g. three-way content merge) determines
+ * it can be cleanly merged, at which point it'll be marked clean
+ * and the algorithm will ignore any data outside the contained
+ * merged_info for that entry
+ * * If an entry remains conflicted, the merged_info portion of a
+ * conflict_info will later be filled with whatever version of
+ * the file should be placed in the working directory (e.g. an
+ * as-merged-as-possible variation that contains conflict markers).
+ */
+ struct strmap paths;
+
+ /*
+ * conflicted: a subset of keys->values from "paths"
+ *
+ * conflicted is basically an optimization between process_entries()
+ * and record_conflicted_index_entries(); the latter could loop over
+ * ALL the entries in paths AGAIN and look for the ones that are
+ * still conflicted, but since process_entries() has to loop over
+ * all of them, it saves the ones it couldn't resolve in this strmap
+ * so that record_conflicted_index_entries() can iterate just the
+ * relevant entries.
+ */
+ struct strmap conflicted;
+
+ /*
+ * paths_to_free: additional list of strings to free
+ *
+ * If keys are removed from "paths", they are added to paths_to_free
+ * to ensure they are later freed. We avoid free'ing immediately since
+ * other places (e.g. conflict_info.pathnames[]) may still be
+ * referencing these paths.
+ */
+ struct string_list paths_to_free;
+
+ /*
+ * output: special messages and conflict notices for various paths
+ *
+ * This is a map of pathnames (a subset of the keys in "paths" above)
+ * to strbufs. It gathers various warning/conflict/notice messages
+ * for later processing.
+ */
+ struct strmap output;
+
+ /*
+ * renames: various data relating to rename detection
+ */
+ struct rename_info renames;
+
+ /*
+ * current_dir_name: temporary var used in collect_merge_info_callback()
+ *
+ * Used to set merged_info.directory_name; see documentation for that
+ * variable and the requirements placed on that field.
+ */
+ const char *current_dir_name;
+
+ /* call_depth: recursion level counter for merging merge bases */
+ int call_depth;
+};
+
+struct version_info {
+ struct object_id oid;
+ unsigned short mode;
+};
+
+struct merged_info {
+ /* if is_null, ignore result. otherwise result has oid & mode */
+ struct version_info result;
+ unsigned is_null:1;
+
+ /*
+ * clean: whether the path in question is cleanly merged.
+ *
+ * see conflict_info.merged for more details.
+ */
+ unsigned clean:1;
+
+ /*
+ * basename_offset: offset of basename of path.
+ *
+ * perf optimization to avoid recomputing offset of final '/'
+ * character in pathname (0 if no '/' in pathname).
+ */
+ size_t basename_offset;
+
+ /*
+ * directory_name: containing directory name.
+ *
+ * Note that we assume directory_name is constructed such that
+ * strcmp(dir1_name, dir2_name) == 0 iff dir1_name == dir2_name,
+ * i.e. string equality is equivalent to pointer equality. For this
+ * to hold, we have to be careful setting directory_name.
+ */
+ const char *directory_name;
+};
+
+struct conflict_info {
+ /*
+ * merged: the version of the path that will be written to working tree
+ *
+ * WARNING: It is critical to check merged.clean and ensure it is 0
+ * before reading any conflict_info fields outside of merged.
+ * Allocated merge_info structs will always have clean set to 1.
+ * Allocated conflict_info structs will have merged.clean set to 0
+ * initially. The merged.clean field is how we know if it is safe
+ * to access other parts of conflict_info besides merged; if a
+ * conflict_info's merged.clean is changed to 1, the rest of the
+ * algorithm is not allowed to look at anything outside of the
+ * merged member anymore.
+ */
+ struct merged_info merged;
+
+ /* oids & modes from each of the three trees for this path */
+ struct version_info stages[3];
+
+ /* pathnames for each stage; may differ due to rename detection */
+ const char *pathnames[3];
+
+ /* Whether this path is/was involved in a directory/file conflict */
+ unsigned df_conflict:1;
+
+ /*
+ * Whether this path is/was involved in a non-content conflict other
+ * than a directory/file conflict (e.g. rename/rename, rename/delete,
+ * file location based on possible directory rename).
+ */
+ unsigned path_conflict:1;
+
+ /*
+ * For filemask and dirmask, the ith bit corresponds to whether the
+ * ith entry is a file (filemask) or a directory (dirmask). Thus,
+ * filemask & dirmask is always zero, and filemask | dirmask is at
+ * most 7 but can be less when a path does not appear as either a
+ * file or a directory on at least one side of history.
+ *
+ * Note that these masks are related to enum merge_side, as the ith
+ * entry corresponds to side i.
+ *
+ * These values come from a traverse_trees() call; more info may be
+ * found looking at tree-walk.h's struct traverse_info,
+ * particularly the documentation above the "fn" member (note that
+ * filemask = mask & ~dirmask from that documentation).
+ */
+ unsigned filemask:3;
+ unsigned dirmask:3;
+
+ /*
+ * Optimization to track which stages match, to avoid the need to
+ * recompute it in multiple steps. Either 0 or at least 2 bits are
+ * set; if at least 2 bits are set, their corresponding stages match.
+ */
+ unsigned match_mask:3;
+};
+
+/*** Function Grouping: various utility functions ***/
+
+/*
+ * For the next three macros, see warning for conflict_info.merged.
+ *
+ * In each of the below, mi is a struct merged_info*, and ci was defined
+ * as a struct conflict_info* (but we need to verify ci isn't actually
+ * pointed at a struct merged_info*).
+ *
+ * INITIALIZE_CI: Assign ci to mi but only if it's safe; set to NULL otherwise.
+ * VERIFY_CI: Ensure that something we assigned to a conflict_info* is one.
+ * ASSIGN_AND_VERIFY_CI: Similar to VERIFY_CI but do assignment first.
+ */
+#define INITIALIZE_CI(ci, mi) do { \
+ (ci) = (!(mi) || (mi)->clean) ? NULL : (struct conflict_info *)(mi); \
+} while (0)
+#define VERIFY_CI(ci) assert(ci && !ci->merged.clean);
+#define ASSIGN_AND_VERIFY_CI(ci, mi) do { \
+ (ci) = (struct conflict_info *)(mi); \
+ assert((ci) && !(mi)->clean); \
+} while (0)
+
+static void free_strmap_strings(struct strmap *map)
+{
+ struct hashmap_iter iter;
+ struct strmap_entry *entry;
+
+ strmap_for_each_entry(map, &iter, entry) {
+ free((char*)entry->key);
+ }
+}
+
+static void clear_or_reinit_internal_opts(struct merge_options_internal *opti,
+ int reinitialize)
+{
+ void (*strmap_func)(struct strmap *, int) =
+ reinitialize ? strmap_partial_clear : strmap_clear;
+
+ /*
+ * We marked opti->paths with strdup_strings = 0, so that we
+ * wouldn't have to make another copy of the fullpath created by
+ * make_traverse_path from setup_path_info(). But, now that we've
+ * used it and have no other references to these strings, it is time
+ * to deallocate them.
+ */
+ free_strmap_strings(&opti->paths);
+ strmap_func(&opti->paths, 1);
+
+ /*
+ * All keys and values in opti->conflicted are a subset of those in
+ * opti->paths. We don't want to deallocate anything twice, so we
+ * don't free the keys and we pass 0 for free_values.
+ */
+ strmap_func(&opti->conflicted, 0);
+
+ /*
+ * opti->paths_to_free is similar to opti->paths; we created it with
+ * strdup_strings = 0 to avoid making _another_ copy of the fullpath
+ * but now that we've used it and have no other references to these
+ * strings, it is time to deallocate them. We do so by temporarily
+ * setting strdup_strings to 1.
+ */
+ opti->paths_to_free.strdup_strings = 1;
+ string_list_clear(&opti->paths_to_free, 0);
+ opti->paths_to_free.strdup_strings = 0;
+
+ if (!reinitialize) {
+ struct hashmap_iter iter;
+ struct strmap_entry *e;
+
+ /* Release and free each strbuf found in output */
+ strmap_for_each_entry(&opti->output, &iter, e) {
+ struct strbuf *sb = e->value;
+ strbuf_release(sb);
+ /*
+ * While strictly speaking we don't need to free(sb)
+ * here because we could pass free_values=1 when
+ * calling strmap_clear() on opti->output, that would
+ * require strmap_clear to do another
+ * strmap_for_each_entry() loop, so we just free it
+ * while we're iterating anyway.
+ */
+ free(sb);
+ }
+ strmap_clear(&opti->output, 0);
+ }
+}
+
+static int err(struct merge_options *opt, const char *err, ...)
+{
+ va_list params;
+ struct strbuf sb = STRBUF_INIT;
+
+ strbuf_addstr(&sb, "error: ");
+ va_start(params, err);
+ strbuf_vaddf(&sb, err, params);
+ va_end(params);
+
+ error("%s", sb.buf);
+ strbuf_release(&sb);
+
+ return -1;
+}
+
+static void format_commit(struct strbuf *sb,
+ int indent,
+ struct commit *commit)
+{
+ struct merge_remote_desc *desc;
+ struct pretty_print_context ctx = {0};
+ ctx.abbrev = DEFAULT_ABBREV;
+
+ strbuf_addchars(sb, ' ', indent);
+ desc = merge_remote_util(commit);
+ if (desc) {
+ strbuf_addf(sb, "virtual %s\n", desc->name);
+ return;
+ }
+
+ format_commit_message(commit, "%h %s", sb, &ctx);
+ strbuf_addch(sb, '\n');
+}
+
+__attribute__((format (printf, 4, 5)))
+static void path_msg(struct merge_options *opt,
+ const char *path,
+ int omittable_hint, /* skippable under --remerge-diff */
+ const char *fmt, ...)
+{
+ va_list ap;
+ struct strbuf *sb = strmap_get(&opt->priv->output, path);
+ if (!sb) {
+ sb = xmalloc(sizeof(*sb));
+ strbuf_init(sb, 0);
+ strmap_put(&opt->priv->output, path, sb);
+ }
+
+ va_start(ap, fmt);
+ strbuf_vaddf(sb, fmt, ap);
+ va_end(ap);
+
+ strbuf_addch(sb, '\n');
+}
+
+/* add a string to a strbuf, but converting "/" to "_" */
+static void add_flattened_path(struct strbuf *out, const char *s)
+{
+ size_t i = out->len;
+ strbuf_addstr(out, s);
+ for (; i < out->len; i++)
+ if (out->buf[i] == '/')
+ out->buf[i] = '_';
+}
+
+static char *unique_path(struct strmap *existing_paths,
+ const char *path,
+ const char *branch)
+{
+ struct strbuf newpath = STRBUF_INIT;
+ int suffix = 0;
+ size_t base_len;
+
+ strbuf_addf(&newpath, "%s~", path);
+ add_flattened_path(&newpath, branch);
+
+ base_len = newpath.len;
+ while (strmap_contains(existing_paths, newpath.buf)) {
+ strbuf_setlen(&newpath, base_len);
+ strbuf_addf(&newpath, "_%d", suffix++);
+ }
+
+ return strbuf_detach(&newpath, NULL);
+}
+
+/*** Function Grouping: functions related to collect_merge_info() ***/
+
+static void setup_path_info(struct merge_options *opt,
+ struct string_list_item *result,
+ const char *current_dir_name,
+ int current_dir_name_len,
+ char *fullpath, /* we'll take over ownership */
+ struct name_entry *names,
+ struct name_entry *merged_version,
+ unsigned is_null, /* boolean */
+ unsigned df_conflict, /* boolean */
+ unsigned filemask,
+ unsigned dirmask,
+ int resolved /* boolean */)
+{
+ /* result->util is void*, so mi is a convenience typed variable */
+ struct merged_info *mi;
+
+ assert(!is_null || resolved);
+ assert(!df_conflict || !resolved); /* df_conflict implies !resolved */
+ assert(resolved == (merged_version != NULL));
+
+ mi = xcalloc(1, resolved ? sizeof(struct merged_info) :
+ sizeof(struct conflict_info));
+ mi->directory_name = current_dir_name;
+ mi->basename_offset = current_dir_name_len;
+ mi->clean = !!resolved;
+ if (resolved) {
+ mi->result.mode = merged_version->mode;
+ oidcpy(&mi->result.oid, &merged_version->oid);
+ mi->is_null = !!is_null;
+ } else {
+ int i;
+ struct conflict_info *ci;
+
+ ASSIGN_AND_VERIFY_CI(ci, mi);
+ for (i = MERGE_BASE; i <= MERGE_SIDE2; i++) {
+ ci->pathnames[i] = fullpath;
+ ci->stages[i].mode = names[i].mode;
+ oidcpy(&ci->stages[i].oid, &names[i].oid);
+ }
+ ci->filemask = filemask;
+ ci->dirmask = dirmask;
+ ci->df_conflict = !!df_conflict;
+ if (dirmask)
+ /*
+ * Assume is_null for now, but if we have entries
+ * under the directory then when it is complete in
+ * write_completed_directory() it'll update this.
+ * Also, for D/F conflicts, we have to handle the
+ * directory first, then clear this bit and process
+ * the file to see how it is handled -- that occurs
+ * near the top of process_entry().
+ */
+ mi->is_null = 1;
+ }
+ strmap_put(&opt->priv->paths, fullpath, mi);
+ result->string = fullpath;
+ result->util = mi;
+}
+
+static int collect_merge_info_callback(int n,
+ unsigned long mask,
+ unsigned long dirmask,
+ struct name_entry *names,
+ struct traverse_info *info)
+{
+ /*
+ * n is 3. Always.
+ * common ancestor (mbase) has mask 1, and stored in index 0 of names
+ * head of side 1 (side1) has mask 2, and stored in index 1 of names
+ * head of side 2 (side2) has mask 4, and stored in index 2 of names
+ */
+ struct merge_options *opt = info->data;
+ struct merge_options_internal *opti = opt->priv;
+ struct string_list_item pi; /* Path Info */
+ struct conflict_info *ci; /* typed alias to pi.util (which is void*) */
+ struct name_entry *p;
+ size_t len;
+ char *fullpath;
+ const char *dirname = opti->current_dir_name;
+ unsigned filemask = mask & ~dirmask;
+ unsigned match_mask = 0; /* will be updated below */
+ unsigned mbase_null = !(mask & 1);
+ unsigned side1_null = !(mask & 2);
+ unsigned side2_null = !(mask & 4);
+ unsigned side1_matches_mbase = (!side1_null && !mbase_null &&
+ names[0].mode == names[1].mode &&
+ oideq(&names[0].oid, &names[1].oid));
+ unsigned side2_matches_mbase = (!side2_null && !mbase_null &&
+ names[0].mode == names[2].mode &&
+ oideq(&names[0].oid, &names[2].oid));
+ unsigned sides_match = (!side1_null && !side2_null &&
+ names[1].mode == names[2].mode &&
+ oideq(&names[1].oid, &names[2].oid));
+
+ /*
+ * Note: When a path is a file on one side of history and a directory
+ * in another, we have a directory/file conflict. In such cases, if
+ * the conflict doesn't resolve from renames and deletions, then we
+ * always leave directories where they are and move files out of the
+ * way. Thus, while struct conflict_info has a df_conflict field to
+ * track such conflicts, we ignore that field for any directories at
+ * a path and only pay attention to it for files at the given path.
+ * The fact that we leave directories were they are also means that
+ * we do not need to worry about getting additional df_conflict
+ * information propagated from parent directories down to children
+ * (unlike, say traverse_trees_recursive() in unpack-trees.c, which
+ * sets a newinfo.df_conflicts field specifically to propagate it).
+ */
+ unsigned df_conflict = (filemask != 0) && (dirmask != 0);
+
+ /* n = 3 is a fundamental assumption. */
+ if (n != 3)
+ BUG("Called collect_merge_info_callback wrong");
+
+ /*
+ * A bunch of sanity checks verifying that traverse_trees() calls
+ * us the way I expect. Could just remove these at some point,
+ * though maybe they are helpful to future code readers.
+ */
+ assert(mbase_null == is_null_oid(&names[0].oid));
+ assert(side1_null == is_null_oid(&names[1].oid));
+ assert(side2_null == is_null_oid(&names[2].oid));
+ assert(!mbase_null || !side1_null || !side2_null);
+ assert(mask > 0 && mask < 8);
+
+ /* Determine match_mask */
+ if (side1_matches_mbase)
+ match_mask = (side2_matches_mbase ? 7 : 3);
+ else if (side2_matches_mbase)
+ match_mask = 5;
+ else if (sides_match)
+ match_mask = 6;
+
+ /*
+ * Get the name of the relevant filepath, which we'll pass to
+ * setup_path_info() for tracking.
+ */
+ p = names;
+ while (!p->mode)
+ p++;
+ len = traverse_path_len(info, p->pathlen);
+
+ /* +1 in both of the following lines to include the NUL byte */
+ fullpath = xmalloc(len + 1);
+ make_traverse_path(fullpath, len + 1, info, p->path, p->pathlen);
+
+ /*
+ * If mbase, side1, and side2 all match, we can resolve early. Even
+ * if these are trees, there will be no renames or anything
+ * underneath.
+ */
+ if (side1_matches_mbase && side2_matches_mbase) {
+ /* mbase, side1, & side2 all match; use mbase as resolution */
+ setup_path_info(opt, &pi, dirname, info->pathlen, fullpath,
+ names, names+0, mbase_null, 0,
+ filemask, dirmask, 1);
+ return mask;
+ }
+
+ /*
+ * Record information about the path so we can resolve later in
+ * process_entries.
+ */
+ setup_path_info(opt, &pi, dirname, info->pathlen, fullpath,
+ names, NULL, 0, df_conflict, filemask, dirmask, 0);
+
+ ci = pi.util;
+ VERIFY_CI(ci);
+ ci->match_mask = match_mask;
+
+ /* If dirmask, recurse into subdirectories */
+ if (dirmask) {
+ struct traverse_info newinfo;
+ struct tree_desc t[3];
+ void *buf[3] = {NULL, NULL, NULL};
+ const char *original_dir_name;
+ int i, ret;
+
+ ci->match_mask &= filemask;
+ newinfo = *info;
+ newinfo.prev = info;
+ newinfo.name = p->path;
+ newinfo.namelen = p->pathlen;
+ newinfo.pathlen = st_add3(newinfo.pathlen, p->pathlen, 1);
+ /*
+ * If this directory we are about to recurse into cared about
+ * its parent directory (the current directory) having a D/F
+ * conflict, then we'd propagate the masks in this way:
+ * newinfo.df_conflicts |= (mask & ~dirmask);
+ * But we don't worry about propagating D/F conflicts. (See
+ * comment near setting of local df_conflict variable near
+ * the beginning of this function).
+ */
+
+ for (i = MERGE_BASE; i <= MERGE_SIDE2; i++) {
+ if (i == 1 && side1_matches_mbase)
+ t[1] = t[0];
+ else if (i == 2 && side2_matches_mbase)
+ t[2] = t[0];
+ else if (i == 2 && sides_match)
+ t[2] = t[1];
+ else {
+ const struct object_id *oid = NULL;
+ if (dirmask & 1)
+ oid = &names[i].oid;
+ buf[i] = fill_tree_descriptor(opt->repo,
+ t + i, oid);
+ }
+ dirmask >>= 1;
+ }
+
+ original_dir_name = opti->current_dir_name;
+ opti->current_dir_name = pi.string;
+ ret = traverse_trees(NULL, 3, t, &newinfo);
+ opti->current_dir_name = original_dir_name;
+
+ for (i = MERGE_BASE; i <= MERGE_SIDE2; i++)
+ free(buf[i]);
+
+ if (ret < 0)
+ return -1;
+ }
+
+ return mask;
+}
+
+static int collect_merge_info(struct merge_options *opt,
+ struct tree *merge_base,
+ struct tree *side1,
+ struct tree *side2)
+{
+ int ret;
+ struct tree_desc t[3];
+ struct traverse_info info;
+ const char *toplevel_dir_placeholder = "";
+
+ opt->priv->current_dir_name = toplevel_dir_placeholder;
+ setup_traverse_info(&info, toplevel_dir_placeholder);
+ info.fn = collect_merge_info_callback;
+ info.data = opt;
+ info.show_all_errors = 1;
+
+ parse_tree(merge_base);
+ parse_tree(side1);
+ parse_tree(side2);
+ init_tree_desc(t + 0, merge_base->buffer, merge_base->size);
+ init_tree_desc(t + 1, side1->buffer, side1->size);
+ init_tree_desc(t + 2, side2->buffer, side2->size);
+
+ ret = traverse_trees(NULL, 3, t, &info);
+
+ return ret;
+}
+
+/*** Function Grouping: functions related to threeway content merges ***/
+
+static int find_first_merges(struct repository *repo,
+ const char *path,
+ struct commit *a,
+ struct commit *b,
+ struct object_array *result)
+{
+ int i, j;
+ struct object_array merges = OBJECT_ARRAY_INIT;
+ struct commit *commit;
+ int contains_another;
+
+ char merged_revision[GIT_MAX_HEXSZ + 2];
+ const char *rev_args[] = { "rev-list", "--merges", "--ancestry-path",
+ "--all", merged_revision, NULL };
+ struct rev_info revs;
+ struct setup_revision_opt rev_opts;
+
+ memset(result, 0, sizeof(struct object_array));
+ memset(&rev_opts, 0, sizeof(rev_opts));
+
+ /* get all revisions that merge commit a */
+ xsnprintf(merged_revision, sizeof(merged_revision), "^%s",
+ oid_to_hex(&a->object.oid));
+ repo_init_revisions(repo, &revs, NULL);
+ rev_opts.submodule = path;
+ /* FIXME: can't handle linked worktrees in submodules yet */
+ revs.single_worktree = path != NULL;
+ setup_revisions(ARRAY_SIZE(rev_args)-1, rev_args, &revs, &rev_opts);
+
+ /* save all revisions from the above list that contain b */
+ if (prepare_revision_walk(&revs))
+ die("revision walk setup failed");
+ while ((commit = get_revision(&revs)) != NULL) {
+ struct object *o = &(commit->object);
+ if (in_merge_bases(b, commit))
+ add_object_array(o, NULL, &merges);
+ }
+ reset_revision_walk();
+
+ /* Now we've got all merges that contain a and b. Prune all
+ * merges that contain another found merge and save them in
+ * result.
+ */
+ for (i = 0; i < merges.nr; i++) {
+ struct commit *m1 = (struct commit *) merges.objects[i].item;
+
+ contains_another = 0;
+ for (j = 0; j < merges.nr; j++) {
+ struct commit *m2 = (struct commit *) merges.objects[j].item;
+ if (i != j && in_merge_bases(m2, m1)) {
+ contains_another = 1;
+ break;
+ }
+ }
+
+ if (!contains_another)
+ add_object_array(merges.objects[i].item, NULL, result);
+ }
+
+ object_array_clear(&merges);
+ return result->nr;
+}
+
+static int merge_submodule(struct merge_options *opt,
+ const char *path,
+ const struct object_id *o,
+ const struct object_id *a,
+ const struct object_id *b,
+ struct object_id *result)
+{
+ struct commit *commit_o, *commit_a, *commit_b;
+ int parent_count;
+ struct object_array merges;
+ struct strbuf sb = STRBUF_INIT;
+
+ int i;
+ int search = !opt->priv->call_depth;
+
+ /* store fallback answer in result in case we fail */
+ oidcpy(result, opt->priv->call_depth ? o : a);
+
+ /* we can not handle deletion conflicts */
+ if (is_null_oid(o))
+ return 0;
+ if (is_null_oid(a))
+ return 0;
+ if (is_null_oid(b))
+ return 0;
+
+ if (add_submodule_odb(path)) {
+ path_msg(opt, path, 0,
+ _("Failed to merge submodule %s (not checked out)"),
+ path);
+ return 0;
+ }
+
+ if (!(commit_o = lookup_commit_reference(opt->repo, o)) ||
+ !(commit_a = lookup_commit_reference(opt->repo, a)) ||
+ !(commit_b = lookup_commit_reference(opt->repo, b))) {
+ path_msg(opt, path, 0,
+ _("Failed to merge submodule %s (commits not present)"),
+ path);
+ return 0;
+ }
+
+ /* check whether both changes are forward */
+ if (!in_merge_bases(commit_o, commit_a) ||
+ !in_merge_bases(commit_o, commit_b)) {
+ path_msg(opt, path, 0,
+ _("Failed to merge submodule %s "
+ "(commits don't follow merge-base)"),
+ path);
+ return 0;
+ }
+
+ /* Case #1: a is contained in b or vice versa */
+ if (in_merge_bases(commit_a, commit_b)) {
+ oidcpy(result, b);
+ path_msg(opt, path, 1,
+ _("Note: Fast-forwarding submodule %s to %s"),
+ path, oid_to_hex(b));
+ return 1;
+ }
+ if (in_merge_bases(commit_b, commit_a)) {
+ oidcpy(result, a);
+ path_msg(opt, path, 1,
+ _("Note: Fast-forwarding submodule %s to %s"),
+ path, oid_to_hex(a));
+ return 1;
+ }
+
+ /*
+ * Case #2: There are one or more merges that contain a and b in
+ * the submodule. If there is only one, then present it as a
+ * suggestion to the user, but leave it marked unmerged so the
+ * user needs to confirm the resolution.
+ */
+
+ /* Skip the search if makes no sense to the calling context. */
+ if (!search)
+ return 0;
+
+ /* find commit which merges them */
+ parent_count = find_first_merges(opt->repo, path, commit_a, commit_b,
+ &merges);
+ switch (parent_count) {
+ case 0:
+ path_msg(opt, path, 0, _("Failed to merge submodule %s"), path);
+ break;
+
+ case 1:
+ format_commit(&sb, 4,
+ (struct commit *)merges.objects[0].item);
+ path_msg(opt, path, 0,
+ _("Failed to merge submodule %s, but a possible merge "
+ "resolution exists:\n%s\n"),
+ path, sb.buf);
+ path_msg(opt, path, 1,
+ _("If this is correct simply add it to the index "
+ "for example\n"
+ "by using:\n\n"
+ " git update-index --cacheinfo 160000 %s \"%s\"\n\n"
+ "which will accept this suggestion.\n"),
+ oid_to_hex(&merges.objects[0].item->oid), path);
+ strbuf_release(&sb);
+ break;
+ default:
+ for (i = 0; i < merges.nr; i++)
+ format_commit(&sb, 4,
+ (struct commit *)merges.objects[i].item);
+ path_msg(opt, path, 0,
+ _("Failed to merge submodule %s, but multiple "
+ "possible merges exist:\n%s"), path, sb.buf);
+ strbuf_release(&sb);
+ }
+
+ object_array_clear(&merges);
+ return 0;
+}
+
+static int merge_3way(struct merge_options *opt,
+ const char *path,
+ const struct object_id *o,
+ const struct object_id *a,
+ const struct object_id *b,
+ const char *pathnames[3],
+ const int extra_marker_size,
+ mmbuffer_t *result_buf)
+{
+ mmfile_t orig, src1, src2;
+ struct ll_merge_options ll_opts = {0};
+ char *base, *name1, *name2;
+ int merge_status;
+
+ ll_opts.renormalize = opt->renormalize;
+ ll_opts.extra_marker_size = extra_marker_size;
+ ll_opts.xdl_opts = opt->xdl_opts;
+
+ if (opt->priv->call_depth) {
+ ll_opts.virtual_ancestor = 1;
+ ll_opts.variant = 0;
+ } else {
+ switch (opt->recursive_variant) {
+ case MERGE_VARIANT_OURS:
+ ll_opts.variant = XDL_MERGE_FAVOR_OURS;
+ break;
+ case MERGE_VARIANT_THEIRS:
+ ll_opts.variant = XDL_MERGE_FAVOR_THEIRS;
+ break;
+ default:
+ ll_opts.variant = 0;
+ break;
+ }
+ }
+
+ assert(pathnames[0] && pathnames[1] && pathnames[2] && opt->ancestor);
+ if (pathnames[0] == pathnames[1] && pathnames[1] == pathnames[2]) {
+ base = mkpathdup("%s", opt->ancestor);
+ name1 = mkpathdup("%s", opt->branch1);
+ name2 = mkpathdup("%s", opt->branch2);
+ } else {
+ base = mkpathdup("%s:%s", opt->ancestor, pathnames[0]);
+ name1 = mkpathdup("%s:%s", opt->branch1, pathnames[1]);
+ name2 = mkpathdup("%s:%s", opt->branch2, pathnames[2]);
+ }
+
+ read_mmblob(&orig, o);
+ read_mmblob(&src1, a);
+ read_mmblob(&src2, b);
+
+ merge_status = ll_merge(result_buf, path, &orig, base,
+ &src1, name1, &src2, name2,
+ opt->repo->index, &ll_opts);
+
+ free(base);
+ free(name1);
+ free(name2);
+ free(orig.ptr);
+ free(src1.ptr);
+ free(src2.ptr);
+ return merge_status;
+}
+
+static int handle_content_merge(struct merge_options *opt,
+ const char *path,
+ const struct version_info *o,
+ const struct version_info *a,
+ const struct version_info *b,
+ const char *pathnames[3],
+ const int extra_marker_size,
+ struct version_info *result)
+{
+ /*
+ * path is the target location where we want to put the file, and
+ * is used to determine any normalization rules in ll_merge.
+ *
+ * The normal case is that path and all entries in pathnames are
+ * identical, though renames can affect which path we got one of
+ * the three blobs to merge on various sides of history.
+ *
+ * extra_marker_size is the amount to extend conflict markers in
+ * ll_merge; this is neeed if we have content merges of content
+ * merges, which happens for example with rename/rename(2to1) and
+ * rename/add conflicts.
+ */
+ unsigned clean = 1;
+
+ /*
+ * handle_content_merge() needs both files to be of the same type, i.e.
+ * both files OR both submodules OR both symlinks. Conflicting types
+ * needs to be handled elsewhere.
+ */
+ assert((S_IFMT & a->mode) == (S_IFMT & b->mode));
+
+ /* Merge modes */
+ if (a->mode == b->mode || a->mode == o->mode)
+ result->mode = b->mode;
+ else {
+ /* must be the 100644/100755 case */
+ assert(S_ISREG(a->mode));
+ result->mode = a->mode;
+ clean = (b->mode == o->mode);
+ /*
+ * FIXME: If opt->priv->call_depth && !clean, then we really
+ * should not make result->mode match either a->mode or
+ * b->mode; that causes t6036 "check conflicting mode for
+ * regular file" to fail. It would be best to use some other
+ * mode, but we'll confuse all kinds of stuff if we use one
+ * where S_ISREG(result->mode) isn't true, and if we use
+ * something like 0100666, then tree-walk.c's calls to
+ * canon_mode() will just normalize that to 100644 for us and
+ * thus not solve anything.
+ *
+ * Figure out if there's some kind of way we can work around
+ * this...
+ */
+ }
+
+ /*
+ * Trivial oid merge.
+ *
+ * Note: While one might assume that the next four lines would
+ * be unnecessary due to the fact that match_mask is often
+ * setup and already handled, renames don't always take care
+ * of that.
+ */
+ if (oideq(&a->oid, &b->oid) || oideq(&a->oid, &o->oid))
+ oidcpy(&result->oid, &b->oid);
+ else if (oideq(&b->oid, &o->oid))
+ oidcpy(&result->oid, &a->oid);
+
+ /* Remaining rules depend on file vs. submodule vs. symlink. */
+ else if (S_ISREG(a->mode)) {
+ mmbuffer_t result_buf;
+ int ret = 0, merge_status;
+ int two_way;
+
+ /*
+ * If 'o' is different type, treat it as null so we do a
+ * two-way merge.
+ */
+ two_way = ((S_IFMT & o->mode) != (S_IFMT & a->mode));
+
+ merge_status = merge_3way(opt, path,
+ two_way ? &null_oid : &o->oid,
+ &a->oid, &b->oid,
+ pathnames, extra_marker_size,
+ &result_buf);
+
+ if ((merge_status < 0) || !result_buf.ptr)
+ ret = err(opt, _("Failed to execute internal merge"));
+
+ if (!ret &&
+ write_object_file(result_buf.ptr, result_buf.size,
+ blob_type, &result->oid))
+ ret = err(opt, _("Unable to add %s to database"),
+ path);
+
+ free(result_buf.ptr);
+ if (ret)
+ return -1;
+ clean &= (merge_status == 0);
+ path_msg(opt, path, 1, _("Auto-merging %s"), path);
+ } else if (S_ISGITLINK(a->mode)) {
+ int two_way = ((S_IFMT & o->mode) != (S_IFMT & a->mode));
+ clean = merge_submodule(opt, pathnames[0],
+ two_way ? &null_oid : &o->oid,
+ &a->oid, &b->oid, &result->oid);
+ if (opt->priv->call_depth && two_way && !clean) {
+ result->mode = o->mode;
+ oidcpy(&result->oid, &o->oid);
+ }
+ } else if (S_ISLNK(a->mode)) {
+ if (opt->priv->call_depth) {
+ clean = 0;
+ result->mode = o->mode;
+ oidcpy(&result->oid, &o->oid);
+ } else {
+ switch (opt->recursive_variant) {
+ case MERGE_VARIANT_NORMAL:
+ clean = 0;
+ oidcpy(&result->oid, &a->oid);
+ break;
+ case MERGE_VARIANT_OURS:
+ oidcpy(&result->oid, &a->oid);
+ break;
+ case MERGE_VARIANT_THEIRS:
+ oidcpy(&result->oid, &b->oid);
+ break;
+ }
+ }
+ } else
+ BUG("unsupported object type in the tree: %06o for %s",
+ a->mode, path);
+
+ return clean;
+}
+
+/*** Function Grouping: functions related to detect_and_process_renames(), ***
+ *** which are split into directory and regular rename detection sections. ***/
+
+/*** Function Grouping: functions related to directory rename detection ***/
+
+/*** Function Grouping: functions related to regular rename detection ***/
+
+static int process_renames(struct merge_options *opt,
+ struct diff_queue_struct *renames)
+{
+ int clean_merge = 1, i;
+
+ for (i = 0; i < renames->nr; ++i) {
+ const char *oldpath = NULL, *newpath;
+ struct diff_filepair *pair = renames->queue[i];
+ struct conflict_info *oldinfo = NULL, *newinfo = NULL;
+ struct strmap_entry *old_ent, *new_ent;
+ unsigned int old_sidemask;
+ int target_index, other_source_index;
+ int source_deleted, collision, type_changed;
+ const char *rename_branch = NULL, *delete_branch = NULL;
+
+ old_ent = strmap_get_entry(&opt->priv->paths, pair->one->path);
+ oldpath = old_ent->key;
+ oldinfo = old_ent->value;
+
+ new_ent = strmap_get_entry(&opt->priv->paths, pair->two->path);
+ newpath = new_ent->key;
+ newinfo = new_ent->value;
+
+ /*
+ * diff_filepairs have copies of pathnames, thus we have to
+ * use standard 'strcmp()' (negated) instead of '=='.
+ */
+ if (i + 1 < renames->nr &&
+ !strcmp(oldpath, renames->queue[i+1]->one->path)) {
+ /* Handle rename/rename(1to2) or rename/rename(1to1) */
+ const char *pathnames[3];
+ struct version_info merged;
+ struct conflict_info *base, *side1, *side2;
+ unsigned was_binary_blob = 0;
+
+ pathnames[0] = oldpath;
+ pathnames[1] = newpath;
+ pathnames[2] = renames->queue[i+1]->two->path;
+
+ base = strmap_get(&opt->priv->paths, pathnames[0]);
+ side1 = strmap_get(&opt->priv->paths, pathnames[1]);
+ side2 = strmap_get(&opt->priv->paths, pathnames[2]);
+
+ VERIFY_CI(base);
+ VERIFY_CI(side1);
+ VERIFY_CI(side2);
+
+ if (!strcmp(pathnames[1], pathnames[2])) {
+ /* Both sides renamed the same way */
+ assert(side1 == side2);
+ memcpy(&side1->stages[0], &base->stages[0],
+ sizeof(merged));
+ side1->filemask |= (1 << MERGE_BASE);
+ /* Mark base as resolved by removal */
+ base->merged.is_null = 1;
+ base->merged.clean = 1;
+
+ /* We handled both renames, i.e. i+1 handled */
+ i++;
+ /* Move to next rename */
+ continue;
+ }
+
+ /* This is a rename/rename(1to2) */
+ clean_merge = handle_content_merge(opt,
+ pair->one->path,
+ &base->stages[0],
+ &side1->stages[1],
+ &side2->stages[2],
+ pathnames,
+ 1 + 2 * opt->priv->call_depth,
+ &merged);
+ if (!clean_merge &&
+ merged.mode == side1->stages[1].mode &&
+ oideq(&merged.oid, &side1->stages[1].oid))
+ was_binary_blob = 1;
+ memcpy(&side1->stages[1], &merged, sizeof(merged));
+ if (was_binary_blob) {
+ /*
+ * Getting here means we were attempting to
+ * merge a binary blob.
+ *
+ * Since we can't merge binaries,
+ * handle_content_merge() just takes one
+ * side. But we don't want to copy the
+ * contents of one side to both paths. We
+ * used the contents of side1 above for
+ * side1->stages, let's use the contents of
+ * side2 for side2->stages below.
+ */
+ oidcpy(&merged.oid, &side2->stages[2].oid);
+ merged.mode = side2->stages[2].mode;
+ }
+ memcpy(&side2->stages[2], &merged, sizeof(merged));
+
+ side1->path_conflict = 1;
+ side2->path_conflict = 1;
+ /*
+ * TODO: For renames we normally remove the path at the
+ * old name. It would thus seem consistent to do the
+ * same for rename/rename(1to2) cases, but we haven't
+ * done so traditionally and a number of the regression
+ * tests now encode an expectation that the file is
+ * left there at stage 1. If we ever decide to change
+ * this, add the following two lines here:
+ * base->merged.is_null = 1;
+ * base->merged.clean = 1;
+ * and remove the setting of base->path_conflict to 1.
+ */
+ base->path_conflict = 1;
+ path_msg(opt, oldpath, 0,
+ _("CONFLICT (rename/rename): %s renamed to "
+ "%s in %s and to %s in %s."),
+ pathnames[0],
+ pathnames[1], opt->branch1,
+ pathnames[2], opt->branch2);
+
+ i++; /* We handled both renames, i.e. i+1 handled */
+ continue;
+ }
+
+ VERIFY_CI(oldinfo);
+ VERIFY_CI(newinfo);
+ target_index = pair->score; /* from collect_renames() */
+ assert(target_index == 1 || target_index == 2);
+ other_source_index = 3 - target_index;
+ old_sidemask = (1 << other_source_index); /* 2 or 4 */
+ source_deleted = (oldinfo->filemask == 1);
+ collision = ((newinfo->filemask & old_sidemask) != 0);
+ type_changed = !source_deleted &&
+ (S_ISREG(oldinfo->stages[other_source_index].mode) !=
+ S_ISREG(newinfo->stages[target_index].mode));
+ if (type_changed && collision) {
+ /*
+ * special handling so later blocks can handle this...
+ *
+ * if type_changed && collision are both true, then this
+ * was really a double rename, but one side wasn't
+ * detected due to lack of break detection. I.e.
+ * something like
+ * orig: has normal file 'foo'
+ * side1: renames 'foo' to 'bar', adds 'foo' symlink
+ * side2: renames 'foo' to 'bar'
+ * In this case, the foo->bar rename on side1 won't be
+ * detected because the new symlink named 'foo' is
+ * there and we don't do break detection. But we detect
+ * this here because we don't want to merge the content
+ * of the foo symlink with the foo->bar file, so we
+ * have some logic to handle this special case. The
+ * easiest way to do that is make 'bar' on side1 not
+ * be considered a colliding file but the other part
+ * of a normal rename. If the file is very different,
+ * well we're going to get content merge conflicts
+ * anyway so it doesn't hurt. And if the colliding
+ * file also has a different type, that'll be handled
+ * by the content merge logic in process_entry() too.
+ *
+ * See also t6430, 'rename vs. rename/symlink'
+ */
+ collision = 0;
+ }
+ if (source_deleted) {
+ if (target_index == 1) {
+ rename_branch = opt->branch1;
+ delete_branch = opt->branch2;
+ } else {
+ rename_branch = opt->branch2;
+ delete_branch = opt->branch1;
+ }
+ }
+
+ assert(source_deleted || oldinfo->filemask & old_sidemask);
+
+ /* Need to check for special types of rename conflicts... */
+ if (collision && !source_deleted) {
+ /* collision: rename/add or rename/rename(2to1) */
+ const char *pathnames[3];
+ struct version_info merged;
+
+ struct conflict_info *base, *side1, *side2;
+ unsigned clean;
+
+ pathnames[0] = oldpath;
+ pathnames[other_source_index] = oldpath;
+ pathnames[target_index] = newpath;
+
+ base = strmap_get(&opt->priv->paths, pathnames[0]);
+ side1 = strmap_get(&opt->priv->paths, pathnames[1]);
+ side2 = strmap_get(&opt->priv->paths, pathnames[2]);
+
+ VERIFY_CI(base);
+ VERIFY_CI(side1);
+ VERIFY_CI(side2);
+
+ clean = handle_content_merge(opt, pair->one->path,
+ &base->stages[0],
+ &side1->stages[1],
+ &side2->stages[2],
+ pathnames,
+ 1 + 2 * opt->priv->call_depth,
+ &merged);
+
+ memcpy(&newinfo->stages[target_index], &merged,
+ sizeof(merged));
+ if (!clean) {
+ path_msg(opt, newpath, 0,
+ _("CONFLICT (rename involved in "
+ "collision): rename of %s -> %s has "
+ "content conflicts AND collides "
+ "with another path; this may result "
+ "in nested conflict markers."),
+ oldpath, newpath);
+ }
+ } else if (collision && source_deleted) {
+ /*
+ * rename/add/delete or rename/rename(2to1)/delete:
+ * since oldpath was deleted on the side that didn't
+ * do the rename, there's not much of a content merge
+ * we can do for the rename. oldinfo->merged.is_null
+ * was already set, so we just leave things as-is so
+ * they look like an add/add conflict.
+ */
+
+ newinfo->path_conflict = 1;
+ path_msg(opt, newpath, 0,
+ _("CONFLICT (rename/delete): %s renamed "
+ "to %s in %s, but deleted in %s."),
+ oldpath, newpath, rename_branch, delete_branch);
+ } else {
+ /*
+ * a few different cases...start by copying the
+ * existing stage(s) from oldinfo over the newinfo
+ * and update the pathname(s).
+ */
+ memcpy(&newinfo->stages[0], &oldinfo->stages[0],
+ sizeof(newinfo->stages[0]));
+ newinfo->filemask |= (1 << MERGE_BASE);
+ newinfo->pathnames[0] = oldpath;
+ if (type_changed) {
+ /* rename vs. typechange */
+ /* Mark the original as resolved by removal */
+ memcpy(&oldinfo->stages[0].oid, &null_oid,
+ sizeof(oldinfo->stages[0].oid));
+ oldinfo->stages[0].mode = 0;
+ oldinfo->filemask &= 0x06;
+ } else if (source_deleted) {
+ /* rename/delete */
+ newinfo->path_conflict = 1;
+ path_msg(opt, newpath, 0,
+ _("CONFLICT (rename/delete): %s renamed"
+ " to %s in %s, but deleted in %s."),
+ oldpath, newpath,
+ rename_branch, delete_branch);
+ } else {
+ /* normal rename */
+ memcpy(&newinfo->stages[other_source_index],
+ &oldinfo->stages[other_source_index],
+ sizeof(newinfo->stages[0]));
+ newinfo->filemask |= (1 << other_source_index);
+ newinfo->pathnames[other_source_index] = oldpath;
+ }
+ }
+
+ if (!type_changed) {
+ /* Mark the original as resolved by removal */
+ oldinfo->merged.is_null = 1;
+ oldinfo->merged.clean = 1;
+ }
+
+ }
+
+ return clean_merge;
+}
+
+static int compare_pairs(const void *a_, const void *b_)
+{
+ const struct diff_filepair *a = *((const struct diff_filepair **)a_);
+ const struct diff_filepair *b = *((const struct diff_filepair **)b_);
+
+ return strcmp(a->one->path, b->one->path);
+}
+
+/* Call diffcore_rename() to compute which files have changed on given side */
+static void detect_regular_renames(struct merge_options *opt,
+ struct tree *merge_base,
+ struct tree *side,
+ unsigned side_index)
+{
+ struct diff_options diff_opts;
+ struct rename_info *renames = &opt->priv->renames;
+
+ repo_diff_setup(opt->repo, &diff_opts);
+ diff_opts.flags.recursive = 1;
+ diff_opts.flags.rename_empty = 0;
+ diff_opts.detect_rename = DIFF_DETECT_RENAME;
+ diff_opts.rename_limit = opt->rename_limit;
+ if (opt->rename_limit <= 0)
+ diff_opts.rename_limit = 1000;
+ diff_opts.rename_score = opt->rename_score;
+ diff_opts.show_rename_progress = opt->show_rename_progress;
+ diff_opts.output_format = DIFF_FORMAT_NO_OUTPUT;
+ diff_setup_done(&diff_opts);
+ diff_tree_oid(&merge_base->object.oid, &side->object.oid, "",
+ &diff_opts);
+ diffcore_std(&diff_opts);
+
+ if (diff_opts.needed_rename_limit > renames->needed_limit)
+ renames->needed_limit = diff_opts.needed_rename_limit;
+
+ renames->pairs[side_index] = diff_queued_diff;
+
+ diff_opts.output_format = DIFF_FORMAT_NO_OUTPUT;
+ diff_queued_diff.nr = 0;
+ diff_queued_diff.queue = NULL;
+ diff_flush(&diff_opts);
+}
+
+/*
+ * Get information of all renames which occurred in 'side_pairs', discarding
+ * non-renames.
+ */
+static int collect_renames(struct merge_options *opt,
+ struct diff_queue_struct *result,
+ unsigned side_index)
+{
+ int i, clean = 1;
+ struct diff_queue_struct *side_pairs;
+ struct rename_info *renames = &opt->priv->renames;
+
+ side_pairs = &renames->pairs[side_index];
+
+ for (i = 0; i < side_pairs->nr; ++i) {
+ struct diff_filepair *p = side_pairs->queue[i];
+
+ if (p->status != 'R') {
+ diff_free_filepair(p);
+ continue;
+ }
+
+ /*
+ * p->score comes back from diffcore_rename_extended() with
+ * the similarity of the renamed file. The similarity is
+ * was used to determine that the two files were related
+ * and are a rename, which we have already used, but beyond
+ * that we have no use for the similarity. So p->score is
+ * now irrelevant. However, process_renames() will need to
+ * know which side of the merge this rename was associated
+ * with, so overwrite p->score with that value.
+ */
+ p->score = side_index;
+ result->queue[result->nr++] = p;
+ }
+
+ return clean;
+}
+
+static int detect_and_process_renames(struct merge_options *opt,
+ struct tree *merge_base,
+ struct tree *side1,
+ struct tree *side2)
+{
+ struct diff_queue_struct combined;
+ struct rename_info *renames = &opt->priv->renames;
+ int s, clean = 1;
+
+ memset(&combined, 0, sizeof(combined));
+
+ detect_regular_renames(opt, merge_base, side1, MERGE_SIDE1);
+ detect_regular_renames(opt, merge_base, side2, MERGE_SIDE2);
+
+ ALLOC_GROW(combined.queue,
+ renames->pairs[1].nr + renames->pairs[2].nr,
+ combined.alloc);
+ clean &= collect_renames(opt, &combined, MERGE_SIDE1);
+ clean &= collect_renames(opt, &combined, MERGE_SIDE2);
+ QSORT(combined.queue, combined.nr, compare_pairs);
+
+ clean &= process_renames(opt, &combined);
+
+ /* Free memory for renames->pairs[] and combined */
+ for (s = MERGE_SIDE1; s <= MERGE_SIDE2; s++) {
+ free(renames->pairs[s].queue);
+ DIFF_QUEUE_CLEAR(&renames->pairs[s]);
+ }
+ if (combined.nr) {
+ int i;
+ for (i = 0; i < combined.nr; i++)
+ diff_free_filepair(combined.queue[i]);
+ free(combined.queue);
+ }
+
+ return clean;
+}
+
+/*** Function Grouping: functions related to process_entries() ***/
+
+static int string_list_df_name_compare(const char *one, const char *two)
+{
+ int onelen = strlen(one);
+ int twolen = strlen(two);
+ /*
+ * Here we only care that entries for D/F conflicts are
+ * adjacent, in particular with the file of the D/F conflict
+ * appearing before files below the corresponding directory.
+ * The order of the rest of the list is irrelevant for us.
+ *
+ * To achieve this, we sort with df_name_compare and provide
+ * the mode S_IFDIR so that D/F conflicts will sort correctly.
+ * We use the mode S_IFDIR for everything else for simplicity,
+ * since in other cases any changes in their order due to
+ * sorting cause no problems for us.
+ */
+ int cmp = df_name_compare(one, onelen, S_IFDIR,
+ two, twolen, S_IFDIR);
+ /*
+ * Now that 'foo' and 'foo/bar' compare equal, we have to make sure
+ * that 'foo' comes before 'foo/bar'.
+ */
+ if (cmp)
+ return cmp;
+ return onelen - twolen;
+}
+
+struct directory_versions {
+ /*
+ * versions: list of (basename -> version_info)
+ *
+ * The basenames are in reverse lexicographic order of full pathnames,
+ * as processed in process_entries(). This puts all entries within
+ * a directory together, and covers the directory itself after
+ * everything within it, allowing us to write subtrees before needing
+ * to record information for the tree itself.
+ */
+ struct string_list versions;
+
+ /*
+ * offsets: list of (full relative path directories -> integer offsets)
+ *
+ * Since versions contains basenames from files in multiple different
+ * directories, we need to know which entries in versions correspond
+ * to which directories. Values of e.g.
+ * "" 0
+ * src 2
+ * src/moduleA 5
+ * Would mean that entries 0-1 of versions are files in the toplevel
+ * directory, entries 2-4 are files under src/, and the remaining
+ * entries starting at index 5 are files under src/moduleA/.
+ */
+ struct string_list offsets;
+
+ /*
+ * last_directory: directory that previously processed file found in
+ *
+ * last_directory starts NULL, but records the directory in which the
+ * previous file was found within. As soon as
+ * directory(current_file) != last_directory
+ * then we need to start updating accounting in versions & offsets.
+ * Note that last_directory is always the last path in "offsets" (or
+ * NULL if "offsets" is empty) so this exists just for quick access.
+ */
+ const char *last_directory;
+
+ /* last_directory_len: cached computation of strlen(last_directory) */
+ unsigned last_directory_len;
+};
+
+static int tree_entry_order(const void *a_, const void *b_)
+{
+ const struct string_list_item *a = a_;
+ const struct string_list_item *b = b_;
+
+ const struct merged_info *ami = a->util;
+ const struct merged_info *bmi = b->util;
+ return base_name_compare(a->string, strlen(a->string), ami->result.mode,
+ b->string, strlen(b->string), bmi->result.mode);
+}
+
+static void write_tree(struct object_id *result_oid,
+ struct string_list *versions,
+ unsigned int offset,
+ size_t hash_size)
+{
+ size_t maxlen = 0, extra;
+ unsigned int nr = versions->nr - offset;
+ struct strbuf buf = STRBUF_INIT;
+ struct string_list relevant_entries = STRING_LIST_INIT_NODUP;
+ int i;
+
+ /*
+ * We want to sort the last (versions->nr-offset) entries in versions.
+ * Do so by abusing the string_list API a bit: make another string_list
+ * that contains just those entries and then sort them.
+ *
+ * We won't use relevant_entries again and will let it just pop off the
+ * stack, so there won't be allocation worries or anything.
+ */
+ relevant_entries.items = versions->items + offset;
+ relevant_entries.nr = versions->nr - offset;
+ QSORT(relevant_entries.items, relevant_entries.nr, tree_entry_order);
+
+ /* Pre-allocate some space in buf */
+ extra = hash_size + 8; /* 8: 6 for mode, 1 for space, 1 for NUL char */
+ for (i = 0; i < nr; i++) {
+ maxlen += strlen(versions->items[offset+i].string) + extra;
+ }
+ strbuf_grow(&buf, maxlen);
+
+ /* Write each entry out to buf */
+ for (i = 0; i < nr; i++) {
+ struct merged_info *mi = versions->items[offset+i].util;
+ struct version_info *ri = &mi->result;
+ strbuf_addf(&buf, "%o %s%c",
+ ri->mode,
+ versions->items[offset+i].string, '\0');
+ strbuf_add(&buf, ri->oid.hash, hash_size);
+ }
+
+ /* Write this object file out, and record in result_oid */
+ write_object_file(buf.buf, buf.len, tree_type, result_oid);
+ strbuf_release(&buf);
+}
+
+static void record_entry_for_tree(struct directory_versions *dir_metadata,
+ const char *path,
+ struct merged_info *mi)
+{
+ const char *basename;
+
+ if (mi->is_null)
+ /* nothing to record */
+ return;
+
+ basename = path + mi->basename_offset;
+ assert(strchr(basename, '/') == NULL);
+ string_list_append(&dir_metadata->versions,
+ basename)->util = &mi->result;
+}
+
+static void write_completed_directory(struct merge_options *opt,
+ const char *new_directory_name,
+ struct directory_versions *info)
+{
+ const char *prev_dir;
+ struct merged_info *dir_info = NULL;
+ unsigned int offset;
+
+ /*
+ * Some explanation of info->versions and info->offsets...
+ *
+ * process_entries() iterates over all relevant files AND
+ * directories in reverse lexicographic order, and calls this
+ * function. Thus, an example of the paths that process_entries()
+ * could operate on (along with the directories for those paths
+ * being shown) is:
+ *
+ * xtract.c ""
+ * tokens.txt ""
+ * src/moduleB/umm.c src/moduleB
+ * src/moduleB/stuff.h src/moduleB
+ * src/moduleB/baz.c src/moduleB
+ * src/moduleB src
+ * src/moduleA/foo.c src/moduleA
+ * src/moduleA/bar.c src/moduleA
+ * src/moduleA src
+ * src ""
+ * Makefile ""
+ *
+ * info->versions:
+ *
+ * always contains the unprocessed entries and their
+ * version_info information. For example, after the first five
+ * entries above, info->versions would be:
+ *
+ * xtract.c <xtract.c's version_info>
+ * token.txt <token.txt's version_info>
+ * umm.c <src/moduleB/umm.c's version_info>
+ * stuff.h <src/moduleB/stuff.h's version_info>
+ * baz.c <src/moduleB/baz.c's version_info>
+ *
+ * Once a subdirectory is completed we remove the entries in
+ * that subdirectory from info->versions, writing it as a tree
+ * (write_tree()). Thus, as soon as we get to src/moduleB,
+ * info->versions would be updated to
+ *
+ * xtract.c <xtract.c's version_info>
+ * token.txt <token.txt's version_info>
+ * moduleB <src/moduleB's version_info>
+ *
+ * info->offsets:
+ *
+ * helps us track which entries in info->versions correspond to
+ * which directories. When we are N directories deep (e.g. 4
+ * for src/modA/submod/subdir/), we have up to N+1 unprocessed
+ * directories (+1 because of toplevel dir). Corresponding to
+ * the info->versions example above, after processing five entries
+ * info->offsets will be:
+ *
+ * "" 0
+ * src/moduleB 2
+ *
+ * which is used to know that xtract.c & token.txt are from the
+ * toplevel dirctory, while umm.c & stuff.h & baz.c are from the
+ * src/moduleB directory. Again, following the example above,
+ * once we need to process src/moduleB, then info->offsets is
+ * updated to
+ *
+ * "" 0
+ * src 2
+ *
+ * which says that moduleB (and only moduleB so far) is in the
+ * src directory.
+ *
+ * One unique thing to note about info->offsets here is that
+ * "src" was not added to info->offsets until there was a path
+ * (a file OR directory) immediately below src/ that got
+ * processed.
+ *
+ * Since process_entry() just appends new entries to info->versions,
+ * write_completed_directory() only needs to do work if the next path
+ * is in a directory that is different than the last directory found
+ * in info->offsets.
+ */
+
+ /*
+ * If we are working with the same directory as the last entry, there
+ * is no work to do. (See comments above the directory_name member of
+ * struct merged_info for why we can use pointer comparison instead of
+ * strcmp here.)
+ */
+ if (new_directory_name == info->last_directory)
+ return;
+
+ /*
+ * If we are just starting (last_directory is NULL), or last_directory
+ * is a prefix of the current directory, then we can just update
+ * info->offsets to record the offset where we started this directory
+ * and update last_directory to have quick access to it.
+ */
+ if (info->last_directory == NULL ||
+ !strncmp(new_directory_name, info->last_directory,
+ info->last_directory_len)) {
+ uintptr_t offset = info->versions.nr;
+
+ info->last_directory = new_directory_name;
+ info->last_directory_len = strlen(info->last_directory);
+ /*
+ * Record the offset into info->versions where we will
+ * start recording basenames of paths found within
+ * new_directory_name.
+ */
+ string_list_append(&info->offsets,
+ info->last_directory)->util = (void*)offset;
+ return;
+ }
+
+ /*
+ * The next entry that will be processed will be within
+ * new_directory_name. Since at this point we know that
+ * new_directory_name is within a different directory than
+ * info->last_directory, we have all entries for info->last_directory
+ * in info->versions and we need to create a tree object for them.
+ */
+ dir_info = strmap_get(&opt->priv->paths, info->last_directory);
+ assert(dir_info);
+ offset = (uintptr_t)info->offsets.items[info->offsets.nr-1].util;
+ if (offset == info->versions.nr) {
+ /*
+ * Actually, we don't need to create a tree object in this
+ * case. Whenever all files within a directory disappear
+ * during the merge (e.g. unmodified on one side and
+ * deleted on the other, or files were renamed elsewhere),
+ * then we get here and the directory itself needs to be
+ * omitted from its parent tree as well.
+ */
+ dir_info->is_null = 1;
+ } else {
+ /*
+ * Write out the tree to the git object directory, and also
+ * record the mode and oid in dir_info->result.
+ */
+ dir_info->is_null = 0;
+ dir_info->result.mode = S_IFDIR;
+ write_tree(&dir_info->result.oid, &info->versions, offset,
+ opt->repo->hash_algo->rawsz);
+ }
+
+ /*
+ * We've now used several entries from info->versions and one entry
+ * from info->offsets, so we get rid of those values.
+ */
+ info->offsets.nr--;
+ info->versions.nr = offset;
+
+ /*
+ * Now we've taken care of the completed directory, but we need to
+ * prepare things since future entries will be in
+ * new_directory_name. (In particular, process_entry() will be
+ * appending new entries to info->versions.) So, we need to make
+ * sure new_directory_name is the last entry in info->offsets.
+ */
+ prev_dir = info->offsets.nr == 0 ? NULL :
+ info->offsets.items[info->offsets.nr-1].string;
+ if (new_directory_name != prev_dir) {
+ uintptr_t c = info->versions.nr;
+ string_list_append(&info->offsets,
+ new_directory_name)->util = (void*)c;
+ }
+
+ /* And, of course, we need to update last_directory to match. */
+ info->last_directory = new_directory_name;
+ info->last_directory_len = strlen(info->last_directory);
+}
+
+/* Per entry merge function */
+static void process_entry(struct merge_options *opt,
+ const char *path,
+ struct conflict_info *ci,
+ struct directory_versions *dir_metadata)
+{
+ int df_file_index = 0;
+
+ VERIFY_CI(ci);
+ assert(ci->filemask >= 0 && ci->filemask <= 7);
+ /* ci->match_mask == 7 was handled in collect_merge_info_callback() */
+ assert(ci->match_mask == 0 || ci->match_mask == 3 ||
+ ci->match_mask == 5 || ci->match_mask == 6);
+
+ if (ci->dirmask) {
+ record_entry_for_tree(dir_metadata, path, &ci->merged);
+ if (ci->filemask == 0)
+ /* nothing else to handle */
+ return;
+ assert(ci->df_conflict);
+ }
+
+ if (ci->df_conflict && ci->merged.result.mode == 0) {
+ int i;
+
+ /*
+ * directory no longer in the way, but we do have a file we
+ * need to place here so we need to clean away the "directory
+ * merges to nothing" result.
+ */
+ ci->df_conflict = 0;
+ assert(ci->filemask != 0);
+ ci->merged.clean = 0;
+ ci->merged.is_null = 0;
+ /* and we want to zero out any directory-related entries */
+ ci->match_mask = (ci->match_mask & ~ci->dirmask);
+ ci->dirmask = 0;
+ for (i = MERGE_BASE; i <= MERGE_SIDE2; i++) {
+ if (ci->filemask & (1 << i))
+ continue;
+ ci->stages[i].mode = 0;
+ oidcpy(&ci->stages[i].oid, &null_oid);
+ }
+ } else if (ci->df_conflict && ci->merged.result.mode != 0) {
+ /*
+ * This started out as a D/F conflict, and the entries in
+ * the competing directory were not removed by the merge as
+ * evidenced by write_completed_directory() writing a value
+ * to ci->merged.result.mode.
+ */
+ struct conflict_info *new_ci;
+ const char *branch;
+ const char *old_path = path;
+ int i;
+
+ assert(ci->merged.result.mode == S_IFDIR);
+
+ /*
+ * If filemask is 1, we can just ignore the file as having
+ * been deleted on both sides. We do not want to overwrite
+ * ci->merged.result, since it stores the tree for all the
+ * files under it.
+ */
+ if (ci->filemask == 1) {
+ ci->filemask = 0;
+ return;
+ }
+
+ /*
+ * This file still exists on at least one side, and we want
+ * the directory to remain here, so we need to move this
+ * path to some new location.
+ */
+ new_ci = xcalloc(1, sizeof(*new_ci));
+ /* We don't really want new_ci->merged.result copied, but it'll
+ * be overwritten below so it doesn't matter. We also don't
+ * want any directory mode/oid values copied, but we'll zero
+ * those out immediately. We do want the rest of ci copied.
+ */
+ memcpy(new_ci, ci, sizeof(*ci));
+ new_ci->match_mask = (new_ci->match_mask & ~new_ci->dirmask);
+ new_ci->dirmask = 0;
+ for (i = MERGE_BASE; i <= MERGE_SIDE2; i++) {
+ if (new_ci->filemask & (1 << i))
+ continue;
+ /* zero out any entries related to directories */
+ new_ci->stages[i].mode = 0;
+ oidcpy(&new_ci->stages[i].oid, &null_oid);
+ }
+
+ /*
+ * Find out which side this file came from; note that we
+ * cannot just use ci->filemask, because renames could cause
+ * the filemask to go back to 7. So we use dirmask, then
+ * pick the opposite side's index.
+ */
+ df_file_index = (ci->dirmask & (1 << 1)) ? 2 : 1;
+ branch = (df_file_index == 1) ? opt->branch1 : opt->branch2;
+ path = unique_path(&opt->priv->paths, path, branch);
+ strmap_put(&opt->priv->paths, path, new_ci);
+
+ path_msg(opt, path, 0,
+ _("CONFLICT (file/directory): directory in the way "
+ "of %s from %s; moving it to %s instead."),
+ old_path, branch, path);
+
+ /*
+ * Zero out the filemask for the old ci. At this point, ci
+ * was just an entry for a directory, so we don't need to
+ * do anything more with it.
+ */
+ ci->filemask = 0;
+
+ /*
+ * Now note that we're working on the new entry (path was
+ * updated above.
+ */
+ ci = new_ci;
+ }
+
+ /*
+ * NOTE: Below there is a long switch-like if-elseif-elseif... block
+ * which the code goes through even for the df_conflict cases
+ * above.
+ */
+ if (ci->match_mask) {
+ ci->merged.clean = 1;
+ if (ci->match_mask == 6) {
+ /* stages[1] == stages[2] */
+ ci->merged.result.mode = ci->stages[1].mode;
+ oidcpy(&ci->merged.result.oid, &ci->stages[1].oid);
+ } else {
+ /* determine the mask of the side that didn't match */
+ unsigned int othermask = 7 & ~ci->match_mask;
+ int side = (othermask == 4) ? 2 : 1;
+
+ ci->merged.result.mode = ci->stages[side].mode;
+ ci->merged.is_null = !ci->merged.result.mode;
+ oidcpy(&ci->merged.result.oid, &ci->stages[side].oid);
+
+ assert(othermask == 2 || othermask == 4);
+ assert(ci->merged.is_null ==
+ (ci->filemask == ci->match_mask));
+ }
+ } else if (ci->filemask >= 6 &&
+ (S_IFMT & ci->stages[1].mode) !=
+ (S_IFMT & ci->stages[2].mode)) {
+ /* Two different items from (file/submodule/symlink) */
+ if (opt->priv->call_depth) {
+ /* Just use the version from the merge base */
+ ci->merged.clean = 0;
+ oidcpy(&ci->merged.result.oid, &ci->stages[0].oid);
+ ci->merged.result.mode = ci->stages[0].mode;
+ ci->merged.is_null = (ci->merged.result.mode == 0);
+ } else {
+ /* Handle by renaming one or both to separate paths. */
+ unsigned o_mode = ci->stages[0].mode;
+ unsigned a_mode = ci->stages[1].mode;
+ unsigned b_mode = ci->stages[2].mode;
+ struct conflict_info *new_ci;
+ const char *a_path = NULL, *b_path = NULL;
+ int rename_a = 0, rename_b = 0;
+
+ new_ci = xmalloc(sizeof(*new_ci));
+
+ if (S_ISREG(a_mode))
+ rename_a = 1;
+ else if (S_ISREG(b_mode))
+ rename_b = 1;
+ else {
+ rename_a = 1;
+ rename_b = 1;
+ }
+
+ path_msg(opt, path, 0,
+ _("CONFLICT (distinct types): %s had different "
+ "types on each side; renamed %s of them so "
+ "each can be recorded somewhere."),
+ path,
+ (rename_a && rename_b) ? _("both") : _("one"));
+
+ ci->merged.clean = 0;
+ memcpy(new_ci, ci, sizeof(*new_ci));
+
+ /* Put b into new_ci, removing a from stages */
+ new_ci->merged.result.mode = ci->stages[2].mode;
+ oidcpy(&new_ci->merged.result.oid, &ci->stages[2].oid);
+ new_ci->stages[1].mode = 0;
+ oidcpy(&new_ci->stages[1].oid, &null_oid);
+ new_ci->filemask = 5;
+ if ((S_IFMT & b_mode) != (S_IFMT & o_mode)) {
+ new_ci->stages[0].mode = 0;
+ oidcpy(&new_ci->stages[0].oid, &null_oid);
+ new_ci->filemask = 4;
+ }
+
+ /* Leave only a in ci, fixing stages. */
+ ci->merged.result.mode = ci->stages[1].mode;
+ oidcpy(&ci->merged.result.oid, &ci->stages[1].oid);
+ ci->stages[2].mode = 0;
+ oidcpy(&ci->stages[2].oid, &null_oid);
+ ci->filemask = 3;
+ if ((S_IFMT & a_mode) != (S_IFMT & o_mode)) {
+ ci->stages[0].mode = 0;
+ oidcpy(&ci->stages[0].oid, &null_oid);
+ ci->filemask = 2;
+ }
+
+ /* Insert entries into opt->priv_paths */
+ assert(rename_a || rename_b);
+ if (rename_a) {
+ a_path = unique_path(&opt->priv->paths,
+ path, opt->branch1);
+ strmap_put(&opt->priv->paths, a_path, ci);
+ }
+
+ if (rename_b)
+ b_path = unique_path(&opt->priv->paths,
+ path, opt->branch2);
+ else
+ b_path = path;
+ strmap_put(&opt->priv->paths, b_path, new_ci);
+
+ if (rename_a && rename_b) {
+ strmap_remove(&opt->priv->paths, path, 0);
+ /*
+ * We removed path from opt->priv->paths. path
+ * will also eventually need to be freed, but
+ * it may still be used by e.g. ci->pathnames.
+ * So, store it in another string-list for now.
+ */
+ string_list_append(&opt->priv->paths_to_free,
+ path);
+ }
+
+ /*
+ * Do special handling for b_path since process_entry()
+ * won't be called on it specially.
+ */
+ strmap_put(&opt->priv->conflicted, b_path, new_ci);
+ record_entry_for_tree(dir_metadata, b_path,
+ &new_ci->merged);
+
+ /*
+ * Remaining code for processing this entry should
+ * think in terms of processing a_path.
+ */
+ if (a_path)
+ path = a_path;
+ }
+ } else if (ci->filemask >= 6) {
+ /* Need a two-way or three-way content merge */
+ struct version_info merged_file;
+ unsigned clean_merge;
+ struct version_info *o = &ci->stages[0];
+ struct version_info *a = &ci->stages[1];
+ struct version_info *b = &ci->stages[2];
+
+ clean_merge = handle_content_merge(opt, path, o, a, b,
+ ci->pathnames,
+ opt->priv->call_depth * 2,
+ &merged_file);
+ ci->merged.clean = clean_merge &&
+ !ci->df_conflict && !ci->path_conflict;
+ ci->merged.result.mode = merged_file.mode;
+ ci->merged.is_null = (merged_file.mode == 0);
+ oidcpy(&ci->merged.result.oid, &merged_file.oid);
+ if (clean_merge && ci->df_conflict) {
+ assert(df_file_index == 1 || df_file_index == 2);
+ ci->filemask = 1 << df_file_index;
+ ci->stages[df_file_index].mode = merged_file.mode;
+ oidcpy(&ci->stages[df_file_index].oid, &merged_file.oid);
+ }
+ if (!clean_merge) {
+ const char *reason = _("content");
+ if (ci->filemask == 6)
+ reason = _("add/add");
+ if (S_ISGITLINK(merged_file.mode))
+ reason = _("submodule");
+ path_msg(opt, path, 0,
+ _("CONFLICT (%s): Merge conflict in %s"),
+ reason, path);
+ }
+ } else if (ci->filemask == 3 || ci->filemask == 5) {
+ /* Modify/delete */
+ const char *modify_branch, *delete_branch;
+ int side = (ci->filemask == 5) ? 2 : 1;
+ int index = opt->priv->call_depth ? 0 : side;
+
+ ci->merged.result.mode = ci->stages[index].mode;
+ oidcpy(&ci->merged.result.oid, &ci->stages[index].oid);
+ ci->merged.clean = 0;
+
+ modify_branch = (side == 1) ? opt->branch1 : opt->branch2;
+ delete_branch = (side == 1) ? opt->branch2 : opt->branch1;
+
+ if (ci->path_conflict &&
+ oideq(&ci->stages[0].oid, &ci->stages[side].oid)) {
+ /*
+ * This came from a rename/delete; no action to take,
+ * but avoid printing "modify/delete" conflict notice
+ * since the contents were not modified.
+ */
+ } else {
+ path_msg(opt, path, 0,
+ _("CONFLICT (modify/delete): %s deleted in %s "
+ "and modified in %s. Version %s of %s left "
+ "in tree."),
+ path, delete_branch, modify_branch,
+ modify_branch, path);
+ }
+ } else if (ci->filemask == 2 || ci->filemask == 4) {
+ /* Added on one side */
+ int side = (ci->filemask == 4) ? 2 : 1;
+ ci->merged.result.mode = ci->stages[side].mode;
+ oidcpy(&ci->merged.result.oid, &ci->stages[side].oid);
+ ci->merged.clean = !ci->df_conflict && !ci->path_conflict;
+ } else if (ci->filemask == 1) {
+ /* Deleted on both sides */
+ ci->merged.is_null = 1;
+ ci->merged.result.mode = 0;
+ oidcpy(&ci->merged.result.oid, &null_oid);
+ ci->merged.clean = !ci->path_conflict;
+ }
+
+ /*
+ * If still conflicted, record it separately. This allows us to later
+ * iterate over just conflicted entries when updating the index instead
+ * of iterating over all entries.
+ */
+ if (!ci->merged.clean)
+ strmap_put(&opt->priv->conflicted, path, ci);
+ record_entry_for_tree(dir_metadata, path, &ci->merged);
+}
+
+static void process_entries(struct merge_options *opt,
+ struct object_id *result_oid)
+{
+ struct hashmap_iter iter;
+ struct strmap_entry *e;
+ struct string_list plist = STRING_LIST_INIT_NODUP;
+ struct string_list_item *entry;
+ struct directory_versions dir_metadata = { STRING_LIST_INIT_NODUP,
+ STRING_LIST_INIT_NODUP,
+ NULL, 0 };
+
+ if (strmap_empty(&opt->priv->paths)) {
+ oidcpy(result_oid, opt->repo->hash_algo->empty_tree);
+ return;
+ }
+
+ /* Hack to pre-allocate plist to the desired size */
+ ALLOC_GROW(plist.items, strmap_get_size(&opt->priv->paths), plist.alloc);
+
+ /* Put every entry from paths into plist, then sort */
+ strmap_for_each_entry(&opt->priv->paths, &iter, e) {
+ string_list_append(&plist, e->key)->util = e->value;
+ }
+ plist.cmp = string_list_df_name_compare;
+ string_list_sort(&plist);
+
+ /*
+ * Iterate over the items in reverse order, so we can handle paths
+ * below a directory before needing to handle the directory itself.
+ *
+ * This allows us to write subtrees before we need to write trees,
+ * and it also enables sane handling of directory/file conflicts
+ * (because it allows us to know whether the directory is still in
+ * the way when it is time to process the file at the same path).
+ */
+ for (entry = &plist.items[plist.nr-1]; entry >= plist.items; --entry) {
+ char *path = entry->string;
+ /*
+ * NOTE: mi may actually be a pointer to a conflict_info, but
+ * we have to check mi->clean first to see if it's safe to
+ * reassign to such a pointer type.
+ */
+ struct merged_info *mi = entry->util;
+
+ write_completed_directory(opt, mi->directory_name,
+ &dir_metadata);
+ if (mi->clean)
+ record_entry_for_tree(&dir_metadata, path, mi);
+ else {
+ struct conflict_info *ci = (struct conflict_info *)mi;
+ process_entry(opt, path, ci, &dir_metadata);
+ }
+ }
+
+ if (dir_metadata.offsets.nr != 1 ||
+ (uintptr_t)dir_metadata.offsets.items[0].util != 0) {
+ printf("dir_metadata.offsets.nr = %d (should be 1)\n",
+ dir_metadata.offsets.nr);
+ printf("dir_metadata.offsets.items[0].util = %u (should be 0)\n",
+ (unsigned)(uintptr_t)dir_metadata.offsets.items[0].util);
+ fflush(stdout);
+ BUG("dir_metadata accounting completely off; shouldn't happen");
+ }
+ write_tree(result_oid, &dir_metadata.versions, 0,
+ opt->repo->hash_algo->rawsz);
+ string_list_clear(&plist, 0);
+ string_list_clear(&dir_metadata.versions, 0);
+ string_list_clear(&dir_metadata.offsets, 0);
+}
+
+/*** Function Grouping: functions related to merge_switch_to_result() ***/
+
+static int checkout(struct merge_options *opt,
+ struct tree *prev,
+ struct tree *next)
+{
+ /* Switch the index/working copy from old to new */
+ int ret;
+ struct tree_desc trees[2];
+ struct unpack_trees_options unpack_opts;
+
+ memset(&unpack_opts, 0, sizeof(unpack_opts));
+ unpack_opts.head_idx = -1;
+ unpack_opts.src_index = opt->repo->index;
+ unpack_opts.dst_index = opt->repo->index;
+
+ setup_unpack_trees_porcelain(&unpack_opts, "merge");
+
+ /*
+ * NOTE: if this were just "git checkout" code, we would probably
+ * read or refresh the cache and check for a conflicted index, but
+ * builtin/merge.c or sequencer.c really needs to read the index
+ * and check for conflicted entries before starting merging for a
+ * good user experience (no sense waiting for merges/rebases before
+ * erroring out), so there's no reason to duplicate that work here.
+ */
+
+ /* 2-way merge to the new branch */
+ unpack_opts.update = 1;
+ unpack_opts.merge = 1;
+ unpack_opts.quiet = 0; /* FIXME: sequencer might want quiet? */
+ unpack_opts.verbose_update = (opt->verbosity > 2);
+ unpack_opts.fn = twoway_merge;
+ if (1/* FIXME: opts->overwrite_ignore*/) {
+ unpack_opts.dir = xcalloc(1, sizeof(*unpack_opts.dir));
+ unpack_opts.dir->flags |= DIR_SHOW_IGNORED;
+ setup_standard_excludes(unpack_opts.dir);
+ }
+ parse_tree(prev);
+ init_tree_desc(&trees[0], prev->buffer, prev->size);
+ parse_tree(next);
+ init_tree_desc(&trees[1], next->buffer, next->size);
+
+ ret = unpack_trees(2, trees, &unpack_opts);
+ clear_unpack_trees_porcelain(&unpack_opts);
+ dir_clear(unpack_opts.dir);
+ FREE_AND_NULL(unpack_opts.dir);
+ return ret;
+}
+
+static int record_conflicted_index_entries(struct merge_options *opt,
+ struct index_state *index,
+ struct strmap *paths,
+ struct strmap *conflicted)
+{
+ struct hashmap_iter iter;
+ struct strmap_entry *e;
+ int errs = 0;
+ int original_cache_nr;
+
+ if (strmap_empty(conflicted))
+ return 0;
+
+ original_cache_nr = index->cache_nr;
+
+ /* Put every entry from paths into plist, then sort */
+ strmap_for_each_entry(conflicted, &iter, e) {
+ const char *path = e->key;
+ struct conflict_info *ci = e->value;
+ int pos;
+ struct cache_entry *ce;
+ int i;
+
+ VERIFY_CI(ci);
+
+ /*
+ * The index will already have a stage=0 entry for this path,
+ * because we created an as-merged-as-possible version of the
+ * file and checkout() moved the working copy and index over
+ * to that version.
+ *
+ * However, previous iterations through this loop will have
+ * added unstaged entries to the end of the cache which
+ * ignore the standard alphabetical ordering of cache
+ * entries and break invariants needed for index_name_pos()
+ * to work. However, we know the entry we want is before
+ * those appended cache entries, so do a temporary swap on
+ * cache_nr to only look through entries of interest.
+ */
+ SWAP(index->cache_nr, original_cache_nr);
+ pos = index_name_pos(index, path, strlen(path));
+ SWAP(index->cache_nr, original_cache_nr);
+ if (pos < 0) {
+ if (ci->filemask != 1)
+ BUG("Conflicted %s but nothing in basic working tree or index; this shouldn't happen", path);
+ cache_tree_invalidate_path(index, path);
+ } else {
+ ce = index->cache[pos];
+
+ /*
+ * Clean paths with CE_SKIP_WORKTREE set will not be
+ * written to the working tree by the unpack_trees()
+ * call in checkout(). Our conflicted entries would
+ * have appeared clean to that code since we ignored
+ * the higher order stages. Thus, we need override
+ * the CE_SKIP_WORKTREE bit and manually write those
+ * files to the working disk here.
+ *
+ * TODO: Implement this CE_SKIP_WORKTREE fixup.
+ */
+
+ /*
+ * Mark this cache entry for removal and instead add
+ * new stage>0 entries corresponding to the
+ * conflicts. If there are many conflicted entries, we
+ * want to avoid memmove'ing O(NM) entries by
+ * inserting the new entries one at a time. So,
+ * instead, we just add the new cache entries to the
+ * end (ignoring normal index requirements on sort
+ * order) and sort the index once we're all done.
+ */
+ ce->ce_flags |= CE_REMOVE;
+ }
+
+ for (i = MERGE_BASE; i <= MERGE_SIDE2; i++) {
+ struct version_info *vi;
+ if (!(ci->filemask & (1ul << i)))
+ continue;
+ vi = &ci->stages[i];
+ ce = make_cache_entry(index, vi->mode, &vi->oid,
+ path, i+1, 0);
+ add_index_entry(index, ce, ADD_CACHE_JUST_APPEND);
+ }
+ }
+
+ /*
+ * Remove the unused cache entries (and invalidate the relevant
+ * cache-trees), then sort the index entries to get the conflicted
+ * entries we added to the end into their right locations.
+ */
+ remove_marked_cache_entries(index, 1);
+ QSORT(index->cache, index->cache_nr, cmp_cache_name_compare);
+
+ return errs;
+}
+
void merge_switch_to_result(struct merge_options *opt,
struct tree *head,
struct merge_result *result,
int update_worktree_and_index,
int display_update_msgs)
{
- die("Not yet implemented");
+ assert(opt->priv == NULL);
+ if (result->clean >= 0 && update_worktree_and_index) {
+ struct merge_options_internal *opti = result->priv;
+
+ if (checkout(opt, head, result->tree)) {
+ /* failure to function */
+ result->clean = -1;
+ return;
+ }
+
+ if (record_conflicted_index_entries(opt, opt->repo->index,
+ &opti->paths,
+ &opti->conflicted)) {
+ /* failure to function */
+ result->clean = -1;
+ return;
+ }
+ }
+
+ if (display_update_msgs) {
+ struct merge_options_internal *opti = result->priv;
+ struct hashmap_iter iter;
+ struct strmap_entry *e;
+ struct string_list olist = STRING_LIST_INIT_NODUP;
+ int i;
+
+ /* Hack to pre-allocate olist to the desired size */
+ ALLOC_GROW(olist.items, strmap_get_size(&opti->output),
+ olist.alloc);
+
+ /* Put every entry from output into olist, then sort */
+ strmap_for_each_entry(&opti->output, &iter, e) {
+ string_list_append(&olist, e->key)->util = e->value;
+ }
+ string_list_sort(&olist);
+
+ /* Iterate over the items, printing them */
+ for (i = 0; i < olist.nr; ++i) {
+ struct strbuf *sb = olist.items[i].util;
+
+ printf("%s", sb->buf);
+ }
+ string_list_clear(&olist, 0);
+
+ /* Also include needed rename limit adjustment now */
+ diff_warn_rename_limit("merge.renamelimit",
+ opti->renames.needed_limit, 0);
+ }
+
merge_finalize(opt, result);
}
void merge_finalize(struct merge_options *opt,
struct merge_result *result)
{
- die("Not yet implemented");
+ struct merge_options_internal *opti = result->priv;
+
+ assert(opt->priv == NULL);
+
+ clear_or_reinit_internal_opts(opti, 0);
+ FREE_AND_NULL(opti);
+}
+
+/*** Function Grouping: helper functions for merge_incore_*() ***/
+
+static inline void set_commit_tree(struct commit *c, struct tree *t)
+{
+ c->maybe_tree = t;
+}
+
+static struct commit *make_virtual_commit(struct repository *repo,
+ struct tree *tree,
+ const char *comment)
+{
+ struct commit *commit = alloc_commit_node(repo);
+
+ set_merge_remote_desc(commit, comment, (struct object *)commit);
+ set_commit_tree(commit, tree);
+ commit->object.parsed = 1;
+ return commit;
+}
+
+static void merge_start(struct merge_options *opt, struct merge_result *result)
+{
+ /* Sanity checks on opt */
+ assert(opt->repo);
+
+ assert(opt->branch1 && opt->branch2);
+
+ assert(opt->detect_directory_renames >= MERGE_DIRECTORY_RENAMES_NONE &&
+ opt->detect_directory_renames <= MERGE_DIRECTORY_RENAMES_TRUE);
+ assert(opt->rename_limit >= -1);
+ assert(opt->rename_score >= 0 && opt->rename_score <= MAX_SCORE);
+ assert(opt->show_rename_progress >= 0 && opt->show_rename_progress <= 1);
+
+ assert(opt->xdl_opts >= 0);
+ assert(opt->recursive_variant >= MERGE_VARIANT_NORMAL &&
+ opt->recursive_variant <= MERGE_VARIANT_THEIRS);
+
+ /*
+ * detect_renames, verbosity, buffer_output, and obuf are ignored
+ * fields that were used by "recursive" rather than "ort" -- but
+ * sanity check them anyway.
+ */
+ assert(opt->detect_renames >= -1 &&
+ opt->detect_renames <= DIFF_DETECT_COPY);
+ assert(opt->verbosity >= 0 && opt->verbosity <= 5);
+ assert(opt->buffer_output <= 2);
+ assert(opt->obuf.len == 0);
+
+ assert(opt->priv == NULL);
+
+ /* Default to histogram diff. Actually, just hardcode it...for now. */
+ opt->xdl_opts = DIFF_WITH_ALG(opt, HISTOGRAM_DIFF);
+
+ /* Initialization of opt->priv, our internal merge data */
+ opt->priv = xcalloc(1, sizeof(*opt->priv));
+
+ /*
+ * Although we initialize opt->priv->paths with strdup_strings=0,
+ * that's just to avoid making yet another copy of an allocated
+ * string. Putting the entry into paths means we are taking
+ * ownership, so we will later free it. paths_to_free is similar.
+ *
+ * In contrast, conflicted just has a subset of keys from paths, so
+ * we don't want to free those (it'd be a duplicate free).
+ */
+ strmap_init_with_options(&opt->priv->paths, NULL, 0);
+ strmap_init_with_options(&opt->priv->conflicted, NULL, 0);
+ string_list_init(&opt->priv->paths_to_free, 0);
+
+ /*
+ * keys & strbufs in output will sometimes need to outlive "paths",
+ * so it will have a copy of relevant keys. It's probably a small
+ * subset of the overall paths that have special output.
+ */
+ strmap_init(&opt->priv->output);
+}
+
+/*** Function Grouping: merge_incore_*() and their internal variants ***/
+
+/*
+ * Originally from merge_trees_internal(); heavily adapted, though.
+ */
+static void merge_ort_nonrecursive_internal(struct merge_options *opt,
+ struct tree *merge_base,
+ struct tree *side1,
+ struct tree *side2,
+ struct merge_result *result)
+{
+ struct object_id working_tree_oid;
+
+ if (collect_merge_info(opt, merge_base, side1, side2) != 0) {
+ /*
+ * TRANSLATORS: The %s arguments are: 1) tree hash of a merge
+ * base, and 2-3) the trees for the two trees we're merging.
+ */
+ err(opt, _("collecting merge info failed for trees %s, %s, %s"),
+ oid_to_hex(&merge_base->object.oid),
+ oid_to_hex(&side1->object.oid),
+ oid_to_hex(&side2->object.oid));
+ result->clean = -1;
+ return;
+ }
+
+ result->clean = detect_and_process_renames(opt, merge_base,
+ side1, side2);
+ process_entries(opt, &working_tree_oid);
+
+ /* Set return values */
+ result->tree = parse_tree_indirect(&working_tree_oid);
+ /* existence of conflicted entries implies unclean */
+ result->clean &= strmap_empty(&opt->priv->conflicted);
+ if (!opt->priv->call_depth) {
+ result->priv = opt->priv;
+ opt->priv = NULL;
+ }
+}
+
+/*
+ * Originally from merge_recursive_internal(); somewhat adapted, though.
+ */
+static void merge_ort_internal(struct merge_options *opt,
+ struct commit_list *merge_bases,
+ struct commit *h1,
+ struct commit *h2,
+ struct merge_result *result)
+{
+ struct commit_list *iter;
+ struct commit *merged_merge_bases;
+ const char *ancestor_name;
+ struct strbuf merge_base_abbrev = STRBUF_INIT;
+
+ if (!merge_bases) {
+ merge_bases = get_merge_bases(h1, h2);
+ /* See merge-ort.h:merge_incore_recursive() declaration NOTE */
+ merge_bases = reverse_commit_list(merge_bases);
+ }
+
+ merged_merge_bases = pop_commit(&merge_bases);
+ if (merged_merge_bases == NULL) {
+ /* if there is no common ancestor, use an empty tree */
+ struct tree *tree;
+
+ tree = lookup_tree(opt->repo, opt->repo->hash_algo->empty_tree);
+ merged_merge_bases = make_virtual_commit(opt->repo, tree,
+ "ancestor");
+ ancestor_name = "empty tree";
+ } else if (merge_bases) {
+ ancestor_name = "merged common ancestors";
+ } else {
+ strbuf_add_unique_abbrev(&merge_base_abbrev,
+ &merged_merge_bases->object.oid,
+ DEFAULT_ABBREV);
+ ancestor_name = merge_base_abbrev.buf;
+ }
+
+ for (iter = merge_bases; iter; iter = iter->next) {
+ const char *saved_b1, *saved_b2;
+ struct commit *prev = merged_merge_bases;
+
+ opt->priv->call_depth++;
+ /*
+ * When the merge fails, the result contains files
+ * with conflict markers. The cleanness flag is
+ * ignored (unless indicating an error), it was never
+ * actually used, as result of merge_trees has always
+ * overwritten it: the committed "conflicts" were
+ * already resolved.
+ */
+ saved_b1 = opt->branch1;
+ saved_b2 = opt->branch2;
+ opt->branch1 = "Temporary merge branch 1";
+ opt->branch2 = "Temporary merge branch 2";
+ merge_ort_internal(opt, NULL, prev, iter->item, result);
+ if (result->clean < 0)
+ return;
+ opt->branch1 = saved_b1;
+ opt->branch2 = saved_b2;
+ opt->priv->call_depth--;
+
+ merged_merge_bases = make_virtual_commit(opt->repo,
+ result->tree,
+ "merged tree");
+ commit_list_insert(prev, &merged_merge_bases->parents);
+ commit_list_insert(iter->item,
+ &merged_merge_bases->parents->next);
+
+ clear_or_reinit_internal_opts(opt->priv, 1);
+ }
+
+ opt->ancestor = ancestor_name;
+ merge_ort_nonrecursive_internal(opt,
+ repo_get_commit_tree(opt->repo,
+ merged_merge_bases),
+ repo_get_commit_tree(opt->repo, h1),
+ repo_get_commit_tree(opt->repo, h2),
+ result);
+ strbuf_release(&merge_base_abbrev);
+ opt->ancestor = NULL; /* avoid accidental re-use of opt->ancestor */
}
void merge_incore_nonrecursive(struct merge_options *opt,
struct tree *side2,
struct merge_result *result)
{
- die("Not yet implemented");
+ assert(opt->ancestor != NULL);
+ merge_start(opt, result);
+ merge_ort_nonrecursive_internal(opt, merge_base, side1, side2, result);
}
void merge_incore_recursive(struct merge_options *opt,
struct commit *side2,
struct merge_result *result)
{
- die("Not yet implemented");
+ /* We set the ancestor label based on the merge_bases */
+ assert(opt->ancestor == NULL);
+
+ merge_start(opt, result);
+ merge_ort_internal(opt, merge_bases, side1, side2, result);
}
projects / thirdparty / git.git / blobdiff