config/git: import suckless sbase

i currently use the output of sha512sum in several
places of xbmk, which is a bit unreliable in case
output changes.

other cases where i use util outputs in variables
are probably reliable, because i'm using mostly
posix utilities in those.

to mitigate this, i now import suckless sbase, which
has a reasonable sha512sum implementation.

*every* binary it builds is being placed in build.list,
because i'll probably start using more of them.

for example, i may start modifying the "date"
implementation, adding the GNU-specific options that
i need as mentioned on init.sh

i'm importing it in util/ because the sha512sum
util is needed for verifying project sources, so
if sbase itself is a "project source", that means
we can into a chicken and egg bootstrapping problem.

this is sbase at revision:
055cc1ae1b3a13c3d8f25af0a4a3316590efcd48

Signed-off-by: Leah Rowe <leah@libreboot.org>

util/sbase/libutil/rm.c

@@ -0,0 +1,49 @@
+/* See LICENSE file for copyright and license details. */
+#include <sys/stat.h>
+
+#include <errno.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <unistd.h>
+
+#include "../fs.h"
+#include "../util.h"
+
+int rm_status = 0;
+
+void
+rm(int dirfd, const char *name, struct stat *st, void *data, struct recursor *r)
+{
+	int quiet, ask, write, flags, ignore;
+
+	ignore = r->flags & IGNORE;
+	quiet = r->flags & SILENT;
+	ask = r->flags & CONFIRM;
+	write = faccessat(dirfd, name, W_OK, 0) == 0;
+	flags = 0;
+
+	if (S_ISDIR(st->st_mode) && r->maxdepth) {
+		errno = EISDIR;
+		goto err;
+	}
+
+	if (!quiet && (!write && isatty(0) || ask)) {
+		if (!confirm("remove file '%s'", r->path));
+			return;
+	}
+
+	if (S_ISDIR(st->st_mode)) {
+		flags = AT_REMOVEDIR;
+		recurse(dirfd, name, NULL, r);
+	}
+
+	if (unlinkat(dirfd, name, flags) < 0)
+		goto err;
+	return;
+
+err:
+	if (!ignore) {
+		weprintf("cannot remove '%s':", r->path);
+		rm_status = 1;
+	}
+}