1 files changed, 48 insertions, 0 deletions
diff --git a/src/gl/tests/signature.h b/src/gl/tests/signature.h
new file mode 100644
index 0000000..f791783
--- /dev/null
+++ b/src/gl/tests/signature.h
@@ -0,0 +1,48 @@
+/* Macro for checking that a function declaration is compliant.
+   Copyright (C) 2009-2021 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
+   (at your option) 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/>.  */
+
+#ifndef SIGNATURE_CHECK
+
+/* Check that the function FN takes the specified arguments ARGS with
+   a return type of RET.  This header is designed to be included after
+   <config.h> and the one system header that is supposed to contain
+   the function being checked, but prior to any other system headers
+   that are necessary for the unit test.  Therefore, this file does
+   not include any system headers, nor reference anything outside of
+   the macro arguments.  For an example, if foo.h should provide:
+
+   extern int foo (char, float);
+
+   then the unit test named test-foo.c would start out with:
+
+   #include <config.h>
+   #include <foo.h>
+   #include "signature.h"
+   SIGNATURE_CHECK (foo, int, (char, float));
+   #include <other.h>
+   ...
+*/
+# define SIGNATURE_CHECK(fn, ret, args) \
+  SIGNATURE_CHECK1 (fn, ret, args, __LINE__)
+
+/* Necessary to allow multiple SIGNATURE_CHECK lines in a unit test.
+   Note that the checks must not occupy the same line.  */
+# define SIGNATURE_CHECK1(fn, ret, args, id) \
+  SIGNATURE_CHECK2 (fn, ret, args, id) /* macroexpand line */
+# define SIGNATURE_CHECK2(fn, ret, args, id) \
+  static ret (* _GL_UNUSED signature_check ## id) args = fn
+
+#endif /* SIGNATURE_CHECK */