+static void run_diff(const char *name,
+ const char *other,
+ struct diff_filespec *one,
+ struct diff_filespec *two,
+ const char *xfrm_msg)
+{
+ const char *pgm = external_diff();
+ if (!pgm &&
+ DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
+ (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
+ /* a filepair that changes between file and symlink
+ * needs to be split into deletion and creation.
+ */
+ struct diff_filespec *null = alloc_filespec(two->path);
+ run_external_diff(NULL, name, other, one, null, xfrm_msg);
+ free(null);
+ null = alloc_filespec(one->path);
+ run_external_diff(NULL, name, other, null, two, xfrm_msg);
+ free(null);
+ }
+ else
+ run_external_diff(pgm, name, other, one, two, xfrm_msg);
+}
+
+void diff_setup(int reverse_diff_)
+{
+ reverse_diff = reverse_diff_;
+}
+
+struct diff_queue_struct diff_queued_diff;
+
+void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
+{
+ if (queue->alloc <= queue->nr) {
+ queue->alloc = alloc_nr(queue->alloc);
+ queue->queue = xrealloc(queue->queue,
+ sizeof(dp) * queue->alloc);
+ }
+ queue->queue[queue->nr++] = dp;
+}
+
+struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
+ struct diff_filespec *one,
+ struct diff_filespec *two)
+{
+ struct diff_filepair *dp = xmalloc(sizeof(*dp));
+ dp->one = one;
+ dp->two = two;
+ dp->score = 0;
+ diff_q(queue, dp);
+ return dp;
+}
+
+void diff_free_filepair(struct diff_filepair *p)
+{
+ diff_free_filespec_data(p->one);
+ diff_free_filespec_data(p->two);
+ free(p);
+}
+
+static void diff_flush_raw(struct diff_filepair *p,
+ int line_termination,
+ int inter_name_termination)
+{
+ int two_paths;
+ char status[10];
+
+ if (line_termination) {
+ const char *err = "path %s cannot be expressed without -z";
+ if (strchr(p->one->path, line_termination) ||
+ strchr(p->one->path, inter_name_termination))
+ die(err, p->one->path);
+ if (strchr(p->two->path, line_termination) ||
+ strchr(p->two->path, inter_name_termination))
+ die(err, p->two->path);
+ }
+
+ switch (p->status) {
+ case 'C': case 'R':
+ two_paths = 1;
+ sprintf(status, "%c%03d", p->status,
+ (int)(0.5 + p->score * 100.0/MAX_SCORE));
+ break;
+ default:
+ two_paths = 0;
+ status[0] = p->status;
+ status[1] = 0;
+ break;
+ }
+ printf(":%06o %06o %s ",
+ p->one->mode, p->two->mode, sha1_to_hex(p->one->sha1));
+ printf("%s %s%c%s",
+ sha1_to_hex(p->two->sha1),
+ status,
+ inter_name_termination,
+ p->one->path);
+ if (two_paths)
+ printf("%c%s", inter_name_termination, p->two->path);
+ putchar(line_termination);
+}
+
+int diff_unmodified_pair(struct diff_filepair *p)
+{
+ /* This function is written stricter than necessary to support
+ * the currently implemented transformers, but the idea is to
+ * let transformers to produce diff_filepairs any way they want,
+ * and filter and clean them up here before producing the output.
+ */
+ struct diff_filespec *one, *two;
+
+ if (DIFF_PAIR_UNMERGED(p))
+ return 0; /* unmerged is interesting */
+
+ one = p->one;
+ two = p->two;
+
+ /* deletion, addition, mode or type change
+ * and rename are all interesting.
+ */
+ if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
+ DIFF_PAIR_MODE_CHANGED(p) ||
+ strcmp(one->path, two->path))
+ return 0;
+
+ /* both are valid and point at the same path. that is, we are
+ * dealing with a change.
+ */
+ if (one->sha1_valid && two->sha1_valid &&
+ !memcmp(one->sha1, two->sha1, sizeof(one->sha1)))
+ return 1; /* no change */
+ if (!one->sha1_valid && !two->sha1_valid)
+ return 1; /* both look at the same file on the filesystem. */
+ return 0;
+}
+
+static void diff_flush_patch(struct diff_filepair *p)
+{
+ const char *name, *other;
+ char msg_[PATH_MAX*2+200], *msg;
+
+ if (diff_unmodified_pair(p))
+ return;
+
+ name = p->one->path;
+ other = (strcmp(name, p->two->path) ? p->two->path : NULL);
+ if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
+ (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
+ return; /* no tree diffs in patch format */
+
+ switch (p->status) {
+ case 'C':
+ sprintf(msg_,
+ "similarity index %d%%\n"
+ "copy from %s\n"
+ "copy to %s\n",
+ (int)(0.5 + p->score * 100.0/MAX_SCORE),
+ p->one->path, p->two->path);
+ msg = msg_;
+ break;
+ case 'R':
+ sprintf(msg_,
+ "similarity index %d%%\n"
+ "rename old %s\n"
+ "rename new %s\n",
+ (int)(0.5 + p->score * 100.0/MAX_SCORE),
+ p->one->path, p->two->path);
+ msg = msg_;
+ break;
+ default:
+ msg = NULL;
+ }
+
+ if (DIFF_PAIR_UNMERGED(p))
+ run_diff(name, NULL, NULL, NULL, NULL);
+ else
+ run_diff(name, other, p->one, p->two, msg);
+}
+
+int diff_needs_to_stay(struct diff_queue_struct *q, int i,
+ struct diff_filespec *it)
+{
+ /* If it will be used in later entry (either stay or used
+ * as the source of rename/copy), we need to copy, not rename.
+ */
+ while (i < q->nr) {
+ struct diff_filepair *p = q->queue[i++];
+ if (!DIFF_FILE_VALID(p->two))
+ continue; /* removed is fine */
+ if (strcmp(p->one->path, it->path))
+ continue; /* not relevant */
+
+ /* p has its src set to *it and it is not a delete;
+ * it will be used for in-place change, rename/copy,
+ * or just stays there. We cannot rename it out.
+ */
+ return 1;
+ }
+ return 0;
+}
+
+int diff_queue_is_empty(void)
+{
+ struct diff_queue_struct *q = &diff_queued_diff;
+ int i;
+ for (i = 0; i < q->nr; i++)
+ if (!diff_unmodified_pair(q->queue[i]))
+ return 0;
+ return 1;
+}
+
+#if DIFF_DEBUG
+void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
+{
+ fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
+ x, one ? : "",
+ s->path,
+ DIFF_FILE_VALID(s) ? "valid" : "invalid",
+ s->mode,
+ s->sha1_valid ? sha1_to_hex(s->sha1) : "");
+ fprintf(stderr, "queue[%d] %s size %lu flags %d\n",
+ x, one ? : "",
+ s->size, s->xfrm_flags);
+}
+
+void diff_debug_filepair(const struct diff_filepair *p, int i)
+{
+ diff_debug_filespec(p->one, i, "one");
+ diff_debug_filespec(p->two, i, "two");
+ fprintf(stderr, "score %d, status %c\n",
+ p->score, p->status ? : '?');
+}
+
+void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
+{
+ int i;
+ if (msg)
+ fprintf(stderr, "%s\n", msg);
+ fprintf(stderr, "q->nr = %d\n", q->nr);
+ for (i = 0; i < q->nr; i++) {
+ struct diff_filepair *p = q->queue[i];
+ diff_debug_filepair(p, i);
+ }
+}
+#endif
+
+static void diff_resolve_rename_copy(void)
+{
+ int i, j;
+ struct diff_filepair *p, *pp;
+ struct diff_queue_struct *q = &diff_queued_diff;
+
+ /* This should not depend on the ordering of things. */
+
+ diff_debug_queue("resolve-rename-copy", q);
+
+ for (i = 0; i < q->nr; i++) {
+ p = q->queue[i];
+ p->status = 0; /* undecided */
+ if (DIFF_PAIR_UNMERGED(p))
+ p->status = 'U';
+ else if (!DIFF_FILE_VALID((p)->one))
+ p->status = 'N';
+ else if (!DIFF_FILE_VALID((p)->two)) {
+ /* Deletion record should be omitted if there
+ * are rename/copy entries using this one as
+ * the source. Then we can say one of them
+ * is a rename and the rest are copies.
+ */
+ p->status = 'D';
+ for (j = 0; j < q->nr; j++) {
+ pp = q->queue[j];
+ if (!strcmp(pp->one->path, p->one->path) &&
+ strcmp(pp->one->path, pp->two->path)) {
+ p->status = 'X';
+ break;
+ }
+ }
+ }
+ else if (DIFF_PAIR_TYPE_CHANGED(p))
+ p->status = 'T';
+
+ /* from this point on, we are dealing with a pair
+ * whose both sides are valid and of the same type, i.e.
+ * either in-place edit or rename/copy edit.
+ */
+ else if (strcmp(p->one->path, p->two->path)) {
+ /* See if there is somebody else anywhere that
+ * will keep the path (either modified or
+ * unmodified). If so, we have to be a copy,
+ * not a rename. In addition, if there is
+ * some other rename or copy that comes later
+ * than us that uses the same source, we
+ * have to be a copy, not a rename.
+ */
+ for (j = 0; j < q->nr; j++) {
+ pp = q->queue[j];
+ if (strcmp(pp->one->path, p->one->path))
+ continue;
+ if (!strcmp(pp->one->path, pp->two->path)) {
+ if (DIFF_FILE_VALID(pp->two)) {
+ /* non-delete */
+ p->status = 'C';
+ break;
+ }
+ continue;
+ }
+ /* pp is a rename/copy ... */
+ if (i < j) {
+ /* ... and comes later than us */
+ p->status = 'C';
+ break;
+ }
+ }
+ if (!p->status)
+ p->status = 'R';
+ }
+ else if (memcmp(p->one->sha1, p->two->sha1, 20) ||
+ p->one->mode != p->two->mode)
+ p->status = 'M';
+ else
+ /* this is a "no-change" entry */
+ p->status = 'X';
+ }
+ diff_debug_queue("resolve-rename-copy done", q);
+}
+
+void diff_flush(int diff_output_style, int resolve_rename_copy)
+{
+ struct diff_queue_struct *q = &diff_queued_diff;
+ int i;
+ int line_termination = '\n';
+ int inter_name_termination = '\t';
+
+ if (diff_output_style == DIFF_FORMAT_MACHINE)
+ line_termination = inter_name_termination = 0;
+ if (resolve_rename_copy)
+ diff_resolve_rename_copy();
+
+ for (i = 0; i < q->nr; i++) {
+ struct diff_filepair *p = q->queue[i];
+ if ((diff_output_style == DIFF_FORMAT_NO_OUTPUT) ||
+ (p->status == 'X'))
+ continue;
+ if (p->status == 0)
+ die("internal error in diff-resolve-rename-copy");
+ switch (diff_output_style) {
+ case DIFF_FORMAT_PATCH:
+ diff_flush_patch(p);
+ break;
+ case DIFF_FORMAT_HUMAN:
+ case DIFF_FORMAT_MACHINE:
+ diff_flush_raw(p, line_termination,
+ inter_name_termination);
+ break;
+ }
+ }
+ for (i = 0; i < q->nr; i++)
+ diff_free_filepair(q->queue[i]);
+ free(q->queue);
+ q->queue = NULL;
+ q->nr = q->alloc = 0;
+}
+