dir.c: refactor is_excluded()

In a similar way to the previous commit, this extracts a new helper
function last_exclude_matching() which returns the last exclude_list
element which matched, or NULL if no match was found.  is_excluded()
becomes a wrapper around this, and just returns 0 or 1 depending on
whether any matching exclude_list element was found.

This allows callers to find out _why_ a given path was excluded,
rather than just whether it was or not, paving the way for a new git
sub-command which allows users to test their exclude lists from the
command line.

Signed-off-by: Adam Spiers <git@adamspiers.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/dir.c b/dir.c
index d1a04136e5a87cfe04172152e8914c96aa541e6b..b9d423452643490536e14a11b9a5cdec696861ab 100644 (file)
--- a/dir.c
+++ b/dir.c
@@ -664,24 +664,44 @@ int is_excluded_from_list(const char *pathname,
        return -1; /* undecided */
 }
 
-static int is_excluded(struct dir_struct *dir, const char *pathname, int *dtype_p)
+/*
+ * Loads the exclude lists for the directory containing pathname, then
+ * scans all exclude lists to determine whether pathname is excluded.
+ * Returns the exclude_list element which matched, or NULL for
+ * undecided.
+ */
+static struct exclude *last_exclude_matching(struct dir_struct *dir,
+                                            const char *pathname,
+                                            int *dtype_p)
 {
        int pathlen = strlen(pathname);
        int st;
+       struct exclude *exclude;
        const char *basename = strrchr(pathname, '/');
        basename = (basename) ? basename+1 : pathname;
 
        prep_exclude(dir, pathname, basename-pathname);
        for (st = EXC_CMDL; st <= EXC_FILE; st++) {
-               switch (is_excluded_from_list(pathname, pathlen,
-                                             basename, dtype_p,
-                                             &dir->exclude_list[st])) {
-               case 0:
-                       return 0;
-               case 1:
-                       return 1;
-               }
+               exclude = last_exclude_matching_from_list(
+                       pathname, pathlen, basename, dtype_p,
+                       &dir->exclude_list[st]);
+               if (exclude)
+                       return exclude;
        }
+       return NULL;
+}
+
+/*
+ * Loads the exclude lists for the directory containing pathname, then
+ * scans all exclude lists to determine whether pathname is excluded.
+ * Returns 1 if true, otherwise 0.
+ */
+static int is_excluded(struct dir_struct *dir, const char *pathname, int *dtype_p)
+{
+       struct exclude *exclude =
+               last_exclude_matching(dir, pathname, dtype_p);
+       if (exclude)
+               return exclude->flags & EXC_FLAG_NEGATIVE ? 0 : 1;
        return 0;
 }