1 files changed, 19 insertions, 0 deletions
diff --git a/usage.c b/usage.c
index 52c2e9605..4dc5c7763 100644
--- a/usage.c
+++ b/usage.c
@@ -29,12 +29,17 @@ static void error_builtin(const char *err, va_list params)
 	report("error: ", err, params);
 }
 
+static void warn_builtin(const char *warn, va_list params)
+{
+	report("warning: ", warn, params);
+}
 
 /* If we are in a dlopen()ed .so write to a global variable would segfault
  * (ugh), so keep things static. */
 static void (*usage_routine)(const char *err) NORETURN = usage_builtin;
 static void (*die_routine)(const char *err, va_list params) NORETURN = die_builtin;
 static void (*error_routine)(const char *err, va_list params) = error_builtin;
+static void (*warn_routine)(const char *err, va_list params) = warn_builtin;
 
 void set_usage_routine(void (*routine)(const char *err) NORETURN)
 {
@@ -51,6 +56,11 @@ void set_error_routine(void (*routine)(const char *err, va_list params))
 	error_routine = routine;
 }
 
+void set_warn_routine(void (*routine)(const char *warn, va_list params))
+{
+	warn_routine = routine;
+}
+
 
 void usage(const char *err)
 {
@@ -75,3 +85,12 @@ int error(const char *err, ...)
 	va_end(params);
 	return -1;
 }
+
+void warn(const char *warn, ...)
+{
+	va_list params;
+
+	va_start(params, warn);
+	warn_routine(warn, params);
+	va_end(params);
+}