1 files changed, 26 insertions, 0 deletions
diff --git a/lib/ccan/str/test/compile_fail-isblank.c b/lib/ccan/str/test/compile_fail-isblank.c
new file mode 100644
index 00000000000..f4cb961d740
--- /dev/null
+++ b/lib/ccan/str/test/compile_fail-isblank.c
@@ -0,0 +1,26 @@
+#define CCAN_STR_DEBUG 1
+#include <ccan/str/str.h>
+
+int main(int argc, char *argv[])
+{
+#ifdef FAIL
+#if !HAVE_BUILTIN_TYPES_COMPATIBLE_P || !HAVE_TYPEOF || !HAVE_ISBLANK
+#error We need typeof to check isblank.
+#endif
+	char
+#else
+	unsigned char
+#endif
+		c = argv[0][0];
+
+#ifdef FAIL
+	/* Fake fail on unsigned char platforms. */
+	BUILD_ASSERT((char)255 < 0);
+#endif
+
+#if HAVE_ISBLANK
+	return isblank(c);
+#else
+	return c;
+#endif
+}