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-rw-r--r--diff-lib.c533
1 files changed, 533 insertions, 0 deletions
diff --git a/diff-lib.c b/diff-lib.c
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index 000000000..ae96c64ca
--- /dev/null
+++ b/diff-lib.c
@@ -0,0 +1,533 @@
+/*
+ * Copyright (C) 2005 Junio C Hamano
+ */
+#include "cache.h"
+#include "quote.h"
+#include "commit.h"
+#include "diff.h"
+#include "diffcore.h"
+#include "revision.h"
+#include "cache-tree.h"
+#include "unpack-trees.h"
+#include "refs.h"
+
+/*
+ * diff-files
+ */
+
+/*
+ * Has the work tree entity been removed?
+ *
+ * Return 1 if it was removed from the work tree, 0 if an entity to be
+ * compared with the cache entry ce still exists (the latter includes
+ * the case where a directory that is not a submodule repository
+ * exists for ce that is a submodule -- it is a submodule that is not
+ * checked out). Return negative for an error.
+ */
+static int check_removed(const struct cache_entry *ce, struct stat *st)
+{
+ if (lstat(ce->name, st) < 0) {
+ if (errno != ENOENT && errno != ENOTDIR)
+ return -1;
+ return 1;
+ }
+ if (has_symlink_leading_path(ce_namelen(ce), ce->name))
+ return 1;
+ if (S_ISDIR(st->st_mode)) {
+ unsigned char sub[20];
+
+ /*
+ * If ce is already a gitlink, we can have a plain
+ * directory (i.e. the submodule is not checked out),
+ * or a checked out submodule. Either case this is not
+ * a case where something was removed from the work tree,
+ * so we will return 0.
+ *
+ * Otherwise, if the directory is not a submodule
+ * repository, that means ce which was a blob turned into
+ * a directory --- the blob was removed!
+ */
+ if (!S_ISGITLINK(ce->ce_mode) &&
+ resolve_gitlink_ref(ce->name, "HEAD", sub))
+ return 1;
+ }
+ return 0;
+}
+
+int run_diff_files(struct rev_info *revs, unsigned int option)
+{
+ int entries, i;
+ int diff_unmerged_stage = revs->max_count;
+ int silent_on_removed = option & DIFF_SILENT_ON_REMOVED;
+ unsigned ce_option = ((option & DIFF_RACY_IS_MODIFIED)
+ ? CE_MATCH_RACY_IS_DIRTY : 0);
+ char symcache[PATH_MAX];
+
+ diff_set_mnemonic_prefix(&revs->diffopt, "i/", "w/");
+
+ if (diff_unmerged_stage < 0)
+ diff_unmerged_stage = 2;
+ entries = active_nr;
+ symcache[0] = '\0';
+ for (i = 0; i < entries; i++) {
+ struct stat st;
+ unsigned int oldmode, newmode;
+ struct cache_entry *ce = active_cache[i];
+ int changed;
+
+ if (DIFF_OPT_TST(&revs->diffopt, QUIET) &&
+ DIFF_OPT_TST(&revs->diffopt, HAS_CHANGES))
+ break;
+
+ if (!ce_path_match(ce, revs->prune_data))
+ continue;
+
+ if (ce_stage(ce)) {
+ struct combine_diff_path *dpath;
+ int num_compare_stages = 0;
+ size_t path_len;
+
+ path_len = ce_namelen(ce);
+
+ dpath = xmalloc(combine_diff_path_size(5, path_len));
+ dpath->path = (char *) &(dpath->parent[5]);
+
+ dpath->next = NULL;
+ dpath->len = path_len;
+ memcpy(dpath->path, ce->name, path_len);
+ dpath->path[path_len] = '\0';
+ hashclr(dpath->sha1);
+ memset(&(dpath->parent[0]), 0,
+ sizeof(struct combine_diff_parent)*5);
+
+ changed = check_removed(ce, &st);
+ if (!changed)
+ dpath->mode = ce_mode_from_stat(ce, st.st_mode);
+ else {
+ if (changed < 0) {
+ perror(ce->name);
+ continue;
+ }
+ if (silent_on_removed)
+ continue;
+ }
+
+ while (i < entries) {
+ struct cache_entry *nce = active_cache[i];
+ int stage;
+
+ if (strcmp(ce->name, nce->name))
+ break;
+
+ /* Stage #2 (ours) is the first parent,
+ * stage #3 (theirs) is the second.
+ */
+ stage = ce_stage(nce);
+ if (2 <= stage) {
+ int mode = nce->ce_mode;
+ num_compare_stages++;
+ hashcpy(dpath->parent[stage-2].sha1, nce->sha1);
+ dpath->parent[stage-2].mode = ce_mode_from_stat(nce, mode);
+ dpath->parent[stage-2].status =
+ DIFF_STATUS_MODIFIED;
+ }
+
+ /* diff against the proper unmerged stage */
+ if (stage == diff_unmerged_stage)
+ ce = nce;
+ i++;
+ }
+ /*
+ * Compensate for loop update
+ */
+ i--;
+
+ if (revs->combine_merges && num_compare_stages == 2) {
+ show_combined_diff(dpath, 2,
+ revs->dense_combined_merges,
+ revs);
+ free(dpath);
+ continue;
+ }
+ free(dpath);
+ dpath = NULL;
+
+ /*
+ * Show the diff for the 'ce' if we found the one
+ * from the desired stage.
+ */
+ diff_unmerge(&revs->diffopt, ce->name, 0, null_sha1);
+ if (ce_stage(ce) != diff_unmerged_stage)
+ continue;
+ }
+
+ if (ce_uptodate(ce))
+ continue;
+
+ changed = check_removed(ce, &st);
+ if (changed) {
+ if (changed < 0) {
+ perror(ce->name);
+ continue;
+ }
+ if (silent_on_removed)
+ continue;
+ diff_addremove(&revs->diffopt, '-', ce->ce_mode,
+ ce->sha1, ce->name);
+ continue;
+ }
+ changed = ce_match_stat(ce, &st, ce_option);
+ if (!changed) {
+ ce_mark_uptodate(ce);
+ if (!DIFF_OPT_TST(&revs->diffopt, FIND_COPIES_HARDER))
+ continue;
+ }
+ oldmode = ce->ce_mode;
+ newmode = ce_mode_from_stat(ce, st.st_mode);
+ diff_change(&revs->diffopt, oldmode, newmode,
+ ce->sha1, (changed ? null_sha1 : ce->sha1),
+ ce->name);
+
+ }
+ diffcore_std(&revs->diffopt);
+ diff_flush(&revs->diffopt);
+ return 0;
+}
+
+/*
+ * diff-index
+ */
+
+struct oneway_unpack_data {
+ struct rev_info *revs;
+ char symcache[PATH_MAX];
+};
+
+/* A file entry went away or appeared */
+static void diff_index_show_file(struct rev_info *revs,
+ const char *prefix,
+ struct cache_entry *ce,
+ const unsigned char *sha1, unsigned int mode)
+{
+ diff_addremove(&revs->diffopt, prefix[0], mode,
+ sha1, ce->name);
+}
+
+static int get_stat_data(struct cache_entry *ce,
+ const unsigned char **sha1p,
+ unsigned int *modep,
+ int cached, int match_missing,
+ struct oneway_unpack_data *cbdata)
+{
+ const unsigned char *sha1 = ce->sha1;
+ unsigned int mode = ce->ce_mode;
+
+ if (!cached) {
+ int changed;
+ struct stat st;
+ changed = check_removed(ce, &st);
+ if (changed < 0)
+ return -1;
+ else if (changed) {
+ if (match_missing) {
+ *sha1p = sha1;
+ *modep = mode;
+ return 0;
+ }
+ return -1;
+ }
+ changed = ce_match_stat(ce, &st, 0);
+ if (changed) {
+ mode = ce_mode_from_stat(ce, st.st_mode);
+ sha1 = null_sha1;
+ }
+ }
+
+ *sha1p = sha1;
+ *modep = mode;
+ return 0;
+}
+
+static void show_new_file(struct oneway_unpack_data *cbdata,
+ struct cache_entry *new,
+ int cached, int match_missing)
+{
+ const unsigned char *sha1;
+ unsigned int mode;
+ struct rev_info *revs = cbdata->revs;
+
+ /*
+ * New file in the index: it might actually be different in
+ * the working copy.
+ */
+ if (get_stat_data(new, &sha1, &mode, cached, match_missing, cbdata) < 0)
+ return;
+
+ diff_index_show_file(revs, "+", new, sha1, mode);
+}
+
+static int show_modified(struct oneway_unpack_data *cbdata,
+ struct cache_entry *old,
+ struct cache_entry *new,
+ int report_missing,
+ int cached, int match_missing)
+{
+ unsigned int mode, oldmode;
+ const unsigned char *sha1;
+ struct rev_info *revs = cbdata->revs;
+
+ if (get_stat_data(new, &sha1, &mode, cached, match_missing, cbdata) < 0) {
+ if (report_missing)
+ diff_index_show_file(revs, "-", old,
+ old->sha1, old->ce_mode);
+ return -1;
+ }
+
+ if (revs->combine_merges && !cached &&
+ (hashcmp(sha1, old->sha1) || hashcmp(old->sha1, new->sha1))) {
+ struct combine_diff_path *p;
+ int pathlen = ce_namelen(new);
+
+ p = xmalloc(combine_diff_path_size(2, pathlen));
+ p->path = (char *) &p->parent[2];
+ p->next = NULL;
+ p->len = pathlen;
+ memcpy(p->path, new->name, pathlen);
+ p->path[pathlen] = 0;
+ p->mode = mode;
+ hashclr(p->sha1);
+ memset(p->parent, 0, 2 * sizeof(struct combine_diff_parent));
+ p->parent[0].status = DIFF_STATUS_MODIFIED;
+ p->parent[0].mode = new->ce_mode;
+ hashcpy(p->parent[0].sha1, new->sha1);
+ p->parent[1].status = DIFF_STATUS_MODIFIED;
+ p->parent[1].mode = old->ce_mode;
+ hashcpy(p->parent[1].sha1, old->sha1);
+ show_combined_diff(p, 2, revs->dense_combined_merges, revs);
+ free(p);
+ return 0;
+ }
+
+ oldmode = old->ce_mode;
+ if (mode == oldmode && !hashcmp(sha1, old->sha1) &&
+ !DIFF_OPT_TST(&revs->diffopt, FIND_COPIES_HARDER))
+ return 0;
+
+ diff_change(&revs->diffopt, oldmode, mode,
+ old->sha1, sha1, old->name);
+ return 0;
+}
+
+/*
+ * This turns all merge entries into "stage 3". That guarantees that
+ * when we read in the new tree (into "stage 1"), we won't lose sight
+ * of the fact that we had unmerged entries.
+ */
+static void mark_merge_entries(void)
+{
+ int i;
+ for (i = 0; i < active_nr; i++) {
+ struct cache_entry *ce = active_cache[i];
+ if (!ce_stage(ce))
+ continue;
+ ce->ce_flags |= CE_STAGEMASK;
+ }
+}
+
+/*
+ * This gets a mix of an existing index and a tree, one pathname entry
+ * at a time. The index entry may be a single stage-0 one, but it could
+ * also be multiple unmerged entries (in which case idx_pos/idx_nr will
+ * give you the position and number of entries in the index).
+ */
+static void do_oneway_diff(struct unpack_trees_options *o,
+ struct cache_entry *idx,
+ struct cache_entry *tree)
+{
+ struct oneway_unpack_data *cbdata = o->unpack_data;
+ struct rev_info *revs = cbdata->revs;
+ int match_missing, cached;
+
+ /*
+ * Backward compatibility wart - "diff-index -m" does
+ * not mean "do not ignore merges", but "match_missing".
+ *
+ * But with the revision flag parsing, that's found in
+ * "!revs->ignore_merges".
+ */
+ cached = o->index_only;
+ match_missing = !revs->ignore_merges;
+
+ if (cached && idx && ce_stage(idx)) {
+ if (tree)
+ diff_unmerge(&revs->diffopt, idx->name, idx->ce_mode, idx->sha1);
+ return;
+ }
+
+ /*
+ * Something added to the tree?
+ */
+ if (!tree) {
+ show_new_file(cbdata, idx, cached, match_missing);
+ return;
+ }
+
+ /*
+ * Something removed from the tree?
+ */
+ if (!idx) {
+ diff_index_show_file(revs, "-", tree, tree->sha1, tree->ce_mode);
+ return;
+ }
+
+ /* Show difference between old and new */
+ show_modified(cbdata, tree, idx, 1, cached, match_missing);
+}
+
+static inline void skip_same_name(struct cache_entry *ce, struct unpack_trees_options *o)
+{
+ int len = ce_namelen(ce);
+ const struct index_state *index = o->src_index;
+
+ while (o->pos < index->cache_nr) {
+ struct cache_entry *next = index->cache[o->pos];
+ if (len != ce_namelen(next))
+ break;
+ if (memcmp(ce->name, next->name, len))
+ break;
+ o->pos++;
+ }
+}
+
+/*
+ * The unpack_trees() interface is designed for merging, so
+ * the different source entries are designed primarily for
+ * the source trees, with the old index being really mainly
+ * used for being replaced by the result.
+ *
+ * For diffing, the index is more important, and we only have a
+ * single tree.
+ *
+ * We're supposed to return how many index entries we want to skip.
+ *
+ * This wrapper makes it all more readable, and takes care of all
+ * the fairly complex unpack_trees() semantic requirements, including
+ * the skipping, the path matching, the type conflict cases etc.
+ */
+static int oneway_diff(struct cache_entry **src, struct unpack_trees_options *o)
+{
+ struct cache_entry *idx = src[0];
+ struct cache_entry *tree = src[1];
+ struct oneway_unpack_data *cbdata = o->unpack_data;
+ struct rev_info *revs = cbdata->revs;
+
+ if (idx && ce_stage(idx))
+ skip_same_name(idx, o);
+
+ /*
+ * Unpack-trees generates a DF/conflict entry if
+ * there was a directory in the index and a tree
+ * in the tree. From a diff standpoint, that's a
+ * delete of the tree and a create of the file.
+ */
+ if (tree == o->df_conflict_entry)
+ tree = NULL;
+
+ if (ce_path_match(idx ? idx : tree, revs->prune_data))
+ do_oneway_diff(o, idx, tree);
+
+ return 0;
+}
+
+int run_diff_index(struct rev_info *revs, int cached)
+{
+ struct object *ent;
+ struct tree *tree;
+ const char *tree_name;
+ struct unpack_trees_options opts;
+ struct tree_desc t;
+ struct oneway_unpack_data unpack_cb;
+
+ mark_merge_entries();
+
+ ent = revs->pending.objects[0].item;
+ tree_name = revs->pending.objects[0].name;
+ tree = parse_tree_indirect(ent->sha1);
+ if (!tree)
+ return error("bad tree object %s", tree_name);
+
+ unpack_cb.revs = revs;
+ unpack_cb.symcache[0] = '\0';
+ memset(&opts, 0, sizeof(opts));
+ opts.head_idx = 1;
+ opts.index_only = cached;
+ opts.merge = 1;
+ opts.fn = oneway_diff;
+ opts.unpack_data = &unpack_cb;
+ opts.src_index = &the_index;
+ opts.dst_index = NULL;
+
+ init_tree_desc(&t, tree->buffer, tree->size);
+ if (unpack_trees(1, &t, &opts))
+ exit(128);
+
+ diff_set_mnemonic_prefix(&revs->diffopt, "c/", cached ? "i/" : "w/");
+ diffcore_std(&revs->diffopt);
+ diff_flush(&revs->diffopt);
+ return 0;
+}
+
+int do_diff_cache(const unsigned char *tree_sha1, struct diff_options *opt)
+{
+ struct tree *tree;
+ struct rev_info revs;
+ int i;
+ struct cache_entry **dst;
+ struct cache_entry *last = NULL;
+ struct unpack_trees_options opts;
+ struct tree_desc t;
+ struct oneway_unpack_data unpack_cb;
+
+ /*
+ * This is used by git-blame to run diff-cache internally;
+ * it potentially needs to repeatedly run this, so we will
+ * start by removing the higher order entries the last round
+ * left behind.
+ */
+ dst = active_cache;
+ for (i = 0; i < active_nr; i++) {
+ struct cache_entry *ce = active_cache[i];
+ if (ce_stage(ce)) {
+ if (last && !strcmp(ce->name, last->name))
+ continue;
+ cache_tree_invalidate_path(active_cache_tree,
+ ce->name);
+ last = ce;
+ ce->ce_flags |= CE_REMOVE;
+ }
+ *dst++ = ce;
+ }
+ active_nr = dst - active_cache;
+
+ init_revisions(&revs, NULL);
+ revs.prune_data = opt->paths;
+ tree = parse_tree_indirect(tree_sha1);
+ if (!tree)
+ die("bad tree object %s", sha1_to_hex(tree_sha1));
+
+ unpack_cb.revs = &revs;
+ unpack_cb.symcache[0] = '\0';
+ memset(&opts, 0, sizeof(opts));
+ opts.head_idx = 1;
+ opts.index_only = 1;
+ opts.merge = 1;
+ opts.fn = oneway_diff;
+ opts.unpack_data = &unpack_cb;
+ opts.src_index = &the_index;
+ opts.dst_index = &the_index;
+
+ init_tree_desc(&t, tree->buffer, tree->size);
+ if (unpack_trees(1, &t, &opts))
+ exit(128);
+ return 0;
+}
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