From 961c23bd227db449039af8208733ac5927b8bf0f Mon Sep 17 00:00:00 2001 From: Lennart Poettering Date: Tue, 27 Mar 2018 14:56:29 +0200 Subject: util: introduce typesafe_qsort(), a typesafe version of qsort()/qsort_safe() It does two things: 1. It derives the element size from the array argument type 2. It derives the right type for the function from the array argument type Using this macro call should make the invocations of qsort() quite a bit safer. --- src/basic/util.h | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/src/basic/util.h b/src/basic/util.h index 4a81243cc..825f04235 100644 --- a/src/basic/util.h +++ b/src/basic/util.h @@ -111,6 +111,14 @@ static inline void qsort_safe(void *base, size_t nmemb, size_t size, comparison_ qsort(base, nmemb, size, compar); } +/* A wrapper around the above, but that adds typesafety: the element size is automatically derived from the type and so + * is the prototype for the comparison function */ +#define typesafe_qsort(p, n, func) \ + ({ \ + int (*_func_)(const typeof(p[0])*, const typeof(p[0])*) = func; \ + qsort_safe((p), (n), sizeof((p)[0]), (__compar_fn_t) _func_); \ + }) + /** * Normal memcpy requires src to be nonnull. We do nothing if n is 0. */ -- cgit v1.2.3