Flatten GNU Make directory structure

third_party/make/xconcat-filename.c

@@ -0,0 +1,42 @@
+/* clang-format off */
+/* Construct a full filename from a directory and a relative filename.
+   Copyright (C) 2001-2004, 2006-2020 Free Software Foundation, Inc.
+
+   This program is free software: you can redistribute it and/or modify it
+   under the terms of the GNU General Public License as published by the
+   Free Software Foundation; either version 3 of the License, or any
+   later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
+
+/* Written by Bruno Haible <haible@clisp.cons.org>.  */
+
+#include "third_party/make/config.h"
+
+/* Specification.  */
+#include "third_party/make/concat-filename.h"
+
+#include "third_party/make/xalloc.h"
+
+/* Concatenate a directory filename, a relative filename and an optional
+   suffix.  The directory may end with the directory separator.  The second
+   argument may not start with the directory separator (it is relative).
+   Return a freshly allocated filename.  */
+char *
+xconcatenated_filename (const char *directory, const char *filename,
+                        const char *suffix)
+{
+  char *result;
+
+  result = concatenated_filename (directory, filename, suffix);
+  if (result == NULL)
+    xalloc_die ();
+
+  return result;
+}