str: add STR_MAX_CHARS().

[ccan] / ccan / str / test / compile_fail-STR_MAX_CHARS.c

diff --git a/ccan/str/test/compile_fail-STR_MAX_CHARS.c b/ccan/str/test/compile_fail-STR_MAX_CHARS.c
new file mode 100644 (file)
index 0000000..74448c1
--- /dev/null
+++ b/ccan/str/test/compile_fail-STR_MAX_CHARS.c
@@ -0,0 +1,23 @@
+#include <ccan/str/str.h>
+
+struct s {
+       int val;
+};
+
+int main(int argc, char *argv[])
+{
+       struct s
+#ifdef FAIL
+#if !HAVE_TYPEOF
+       #error We need typeof to check STR_MAX_CHARS.
+#endif
+#else
+       /* A pointer is OK. */
+               *
+#endif
+               val;
+       char str[STR_MAX_CHARS(val)];
+
+       str[0] = '\0';
+       return str[0] ? 0 : 1;
+}