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-rw-r--r--diff-lib.c526
1 files changed, 526 insertions, 0 deletions
diff --git a/diff-lib.c b/diff-lib.c
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+++ b/diff-lib.c
@@ -0,0 +1,526 @@
+/*
+ * 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"
+#include "submodule.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->name, ce_namelen(ce)))
+ 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;
+}
+
+/*
+ * Has a file changed or has a submodule new commits or a dirty work tree?
+ *
+ * Return 1 when changes are detected, 0 otherwise. If the DIRTY_SUBMODULES
+ * option is set, the caller does not only want to know if a submodule is
+ * modified at all but wants to know all the conditions that are met (new
+ * commits, untracked content and/or modified content).
+ */
+static int match_stat_with_submodule(struct diff_options *diffopt,
+ const struct cache_entry *ce,
+ struct stat *st, unsigned ce_option,
+ unsigned *dirty_submodule)
+{
+ int changed = ce_match_stat(ce, st, ce_option);
+ if (S_ISGITLINK(ce->ce_mode)) {
+ unsigned orig_flags = diffopt->flags;
+ if (!DIFF_OPT_TST(diffopt, OVERRIDE_SUBMODULE_CONFIG))
+ set_diffopt_flags_from_submodule_config(diffopt, ce->name);
+ if (DIFF_OPT_TST(diffopt, IGNORE_SUBMODULES))
+ changed = 0;
+ else if (!DIFF_OPT_TST(diffopt, IGNORE_DIRTY_SUBMODULES)
+ && (!changed || DIFF_OPT_TST(diffopt, DIRTY_SUBMODULES)))
+ *dirty_submodule = is_submodule_modified(ce->name, DIFF_OPT_TST(diffopt, IGNORE_UNTRACKED_IN_SUBMODULES));
+ diffopt->flags = orig_flags;
+ }
+ return changed;
+}
+
+int run_diff_files(struct rev_info *revs, unsigned int option)
+{
+ int entries, i;
+ int diff_unmerged_stage = revs->max_count;
+ unsigned ce_option = ((option & DIFF_RACY_IS_MODIFIED)
+ ? CE_MATCH_RACY_IS_DIRTY : 0);
+
+ if (option & DIFF_SILENT_ON_REMOVED)
+ handle_deprecated_show_diff_q(&revs->diffopt);
+
+ diff_set_mnemonic_prefix(&revs->diffopt, "i/", "w/");
+
+ if (diff_unmerged_stage < 0)
+ diff_unmerged_stage = 2;
+ entries = active_nr;
+ for (i = 0; i < entries; i++) {
+ struct stat st;
+ unsigned int oldmode, newmode;
+ struct cache_entry *ce = active_cache[i];
+ int changed;
+ unsigned dirty_submodule = 0;
+
+ if (diff_can_quit_early(&revs->diffopt))
+ break;
+
+ if (!ce_path_match(ce, &revs->prune_data))
+ continue;
+
+ if (ce_stage(ce)) {
+ struct combine_diff_path *dpath;
+ struct diff_filepair *pair;
+ unsigned int wt_mode = 0;
+ 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)
+ wt_mode = ce_mode_from_stat(ce, st.st_mode);
+ else {
+ if (changed < 0) {
+ perror(ce->name);
+ continue;
+ }
+ wt_mode = 0;
+ }
+ dpath->mode = wt_mode;
+
+ 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.
+ */
+ pair = diff_unmerge(&revs->diffopt, ce->name);
+ if (wt_mode)
+ pair->two->mode = wt_mode;
+ if (ce_stage(ce) != diff_unmerged_stage)
+ continue;
+ }
+
+ if (ce_uptodate(ce) || ce_skip_worktree(ce))
+ continue;
+
+ /* If CE_VALID is set, don't look at workdir for file removal */
+ changed = (ce->ce_flags & CE_VALID) ? 0 : check_removed(ce, &st);
+ if (changed) {
+ if (changed < 0) {
+ perror(ce->name);
+ continue;
+ }
+ diff_addremove(&revs->diffopt, '-', ce->ce_mode,
+ ce->sha1, !is_null_sha1(ce->sha1),
+ ce->name, 0);
+ continue;
+ }
+ changed = match_stat_with_submodule(&revs->diffopt, ce, &st,
+ ce_option, &dirty_submodule);
+ if (!changed && !dirty_submodule) {
+ 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),
+ !is_null_sha1(ce->sha1), (changed ? 0 : !is_null_sha1(ce->sha1)),
+ ce->name, 0, dirty_submodule);
+
+ }
+ diffcore_std(&revs->diffopt);
+ diff_flush(&revs->diffopt);
+ return 0;
+}
+
+/*
+ * diff-index
+ */
+
+/* A file entry went away or appeared */
+static void diff_index_show_file(struct rev_info *revs,
+ const char *prefix,
+ const struct cache_entry *ce,
+ const unsigned char *sha1, int sha1_valid,
+ unsigned int mode,
+ unsigned dirty_submodule)
+{
+ diff_addremove(&revs->diffopt, prefix[0], mode,
+ sha1, sha1_valid, ce->name, dirty_submodule);
+}
+
+static int get_stat_data(const struct cache_entry *ce,
+ const unsigned char **sha1p,
+ unsigned int *modep,
+ int cached, int match_missing,
+ unsigned *dirty_submodule, struct diff_options *diffopt)
+{
+ const unsigned char *sha1 = ce->sha1;
+ unsigned int mode = ce->ce_mode;
+
+ if (!cached && !ce_uptodate(ce)) {
+ 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 = match_stat_with_submodule(diffopt, ce, &st,
+ 0, dirty_submodule);
+ 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 rev_info *revs,
+ const struct cache_entry *new,
+ int cached, int match_missing)
+{
+ const unsigned char *sha1;
+ unsigned int mode;
+ unsigned dirty_submodule = 0;
+
+ /*
+ * New file in the index: it might actually be different in
+ * the working tree.
+ */
+ if (get_stat_data(new, &sha1, &mode, cached, match_missing,
+ &dirty_submodule, &revs->diffopt) < 0)
+ return;
+
+ diff_index_show_file(revs, "+", new, sha1, !is_null_sha1(sha1), mode, dirty_submodule);
+}
+
+static int show_modified(struct rev_info *revs,
+ const struct cache_entry *old,
+ const struct cache_entry *new,
+ int report_missing,
+ int cached, int match_missing)
+{
+ unsigned int mode, oldmode;
+ const unsigned char *sha1;
+ unsigned dirty_submodule = 0;
+
+ if (get_stat_data(new, &sha1, &mode, cached, match_missing,
+ &dirty_submodule, &revs->diffopt) < 0) {
+ if (report_missing)
+ diff_index_show_file(revs, "-", old,
+ old->sha1, 1, old->ce_mode, 0);
+ 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) && !dirty_submodule &&
+ !DIFF_OPT_TST(&revs->diffopt, FIND_COPIES_HARDER))
+ return 0;
+
+ diff_change(&revs->diffopt, oldmode, mode,
+ old->sha1, sha1, 1, !is_null_sha1(sha1),
+ old->name, 0, dirty_submodule);
+ return 0;
+}
+
+/*
+ * 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,
+ const struct cache_entry *idx,
+ const struct cache_entry *tree)
+{
+ struct rev_info *revs = o->unpack_data;
+ int match_missing, cached;
+
+ /* if the entry is not checked out, don't examine work tree */
+ cached = o->index_only ||
+ (idx && ((idx->ce_flags & CE_VALID) || ce_skip_worktree(idx)));
+ /*
+ * 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".
+ */
+ match_missing = !revs->ignore_merges;
+
+ if (cached && idx && ce_stage(idx)) {
+ struct diff_filepair *pair;
+ pair = diff_unmerge(&revs->diffopt, idx->name);
+ if (tree)
+ fill_filespec(pair->one, tree->sha1, 1, tree->ce_mode);
+ return;
+ }
+
+ /*
+ * Something added to the tree?
+ */
+ if (!tree) {
+ show_new_file(revs, idx, cached, match_missing);
+ return;
+ }
+
+ /*
+ * Something removed from the tree?
+ */
+ if (!idx) {
+ diff_index_show_file(revs, "-", tree, tree->sha1, 1, tree->ce_mode, 0);
+ return;
+ }
+
+ /* Show difference between old and new */
+ show_modified(revs, tree, idx, 1, cached, match_missing);
+}
+
+/*
+ * 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 advance o->pos to skip what we have already processed.
+ *
+ * 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(const struct cache_entry * const *src,
+ struct unpack_trees_options *o)
+{
+ const struct cache_entry *idx = src[0];
+ const struct cache_entry *tree = src[1];
+ struct rev_info *revs = o->unpack_data;
+
+ /*
+ * 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);
+ if (diff_can_quit_early(&revs->diffopt)) {
+ o->exiting_early = 1;
+ return -1;
+ }
+ }
+
+ return 0;
+}
+
+static int diff_cache(struct rev_info *revs,
+ const unsigned char *tree_sha1,
+ const char *tree_name,
+ int cached)
+{
+ struct tree *tree;
+ struct tree_desc t;
+ struct unpack_trees_options opts;
+
+ tree = parse_tree_indirect(tree_sha1);
+ if (!tree)
+ return error("bad tree object %s",
+ tree_name ? tree_name : sha1_to_hex(tree_sha1));
+ memset(&opts, 0, sizeof(opts));
+ opts.head_idx = 1;
+ opts.index_only = cached;
+ opts.diff_index_cached = (cached &&
+ !DIFF_OPT_TST(&revs->diffopt, FIND_COPIES_HARDER));
+ opts.merge = 1;
+ opts.fn = oneway_diff;
+ opts.unpack_data = revs;
+ opts.src_index = &the_index;
+ opts.dst_index = NULL;
+ opts.pathspec = &revs->diffopt.pathspec;
+ opts.pathspec->recursive = 1;
+
+ init_tree_desc(&t, tree->buffer, tree->size);
+ return unpack_trees(1, &t, &opts);
+}
+
+int run_diff_index(struct rev_info *revs, int cached)
+{
+ struct object_array_entry *ent;
+
+ ent = revs->pending.objects;
+ if (diff_cache(revs, ent->item->sha1, ent->name, cached))
+ exit(128);
+
+ diff_set_mnemonic_prefix(&revs->diffopt, "c/", cached ? "i/" : "w/");
+ diffcore_fix_diff_index(&revs->diffopt);
+ diffcore_std(&revs->diffopt);
+ diff_flush(&revs->diffopt);
+ return 0;
+}
+
+int do_diff_cache(const unsigned char *tree_sha1, struct diff_options *opt)
+{
+ struct rev_info revs;
+
+ init_revisions(&revs, NULL);
+ copy_pathspec(&revs.prune_data, &opt->pathspec);
+ revs.diffopt = *opt;
+
+ if (diff_cache(&revs, tree_sha1, NULL, 1))
+ exit(128);
+ return 0;
+}
+
+int index_differs_from(const char *def, int diff_flags)
+{
+ struct rev_info rev;
+ struct setup_revision_opt opt;
+
+ init_revisions(&rev, NULL);
+ memset(&opt, 0, sizeof(opt));
+ opt.def = def;
+ setup_revisions(0, NULL, &rev, &opt);
+ DIFF_OPT_SET(&rev.diffopt, QUICK);
+ DIFF_OPT_SET(&rev.diffopt, EXIT_WITH_STATUS);
+ rev.diffopt.flags |= diff_flags;
+ run_diff_index(&rev, 1);
+ if (rev.pending.alloc)
+ free(rev.pending.objects);
+ return (DIFF_OPT_TST(&rev.diffopt, HAS_CHANGES) != 0);
+}