Found with -Wmissing-prototypes:
src/hlua_fcn.c:53:5: fatal error: no previous prototype for function 'hlua_checkboolean' [-Wmissing-prototypes]
int hlua_checkboolean(lua_State *L, int index)
^
src/hlua_fcn.c:53:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
int hlua_checkboolean(lua_State *L, int index)
^
static
1 error generated.
#include <haproxy/cli-t.h>
#include <haproxy/errors.h>
#include <haproxy/hlua-t.h>
+#include <haproxy/hlua_fcn.h>
#include <haproxy/http.h>
#include <haproxy/net_helper.h>
#include <haproxy/pattern-t.h>