portability: check for qsort_r which does not match POSIX-next definitionfix/portability-broken-qsort-r

FreeBSD (and also Darwin) introduced its own qsort_r, which has different
semantics than the one slated for inclusion in POSIX.  Add a portability
thunk to deal with translating between implementations.

1 files changed, 26 insertions, 0 deletions

diff --git a/portability/stdlib.h b/portability/stdlib.h
index 6254c7c..d213ae7 100644
--- a/portability/stdlib.h
+++ b/portability/stdlib.h
@@ -1,3 +1,4 @@
+#pragma once
 #include_next <stdlib.h>
 
 #ifdef NEED_QSORT_R
@@ -5,3 +6,28 @@ void qsort_r(void *base, size_t nmemb, size_t size,
 	int (*compar)(const void *, const void *, void *),
 	void *arg);
 #endif
+
+#ifdef HAVE_BROKEN_QSORT_R
+struct __apk_qsort_r_compat_arg {
+	int (*compar)(const void *, const void *, void *);
+	void *arg;
+};
+
+static inline int __apk_qsort_r_compar_compat(void *arg, const void *a, const void *b)
+{
+	struct __apk_qsort_r_compat_arg *compat_arg = arg;
+	return compat_arg->compar(a, b, compat_arg->arg);
+}
+
+static inline void __apk_qsort_r(void *base, size_t nmemb, size_t size,
+				 int (*compar)(const void *, const void *, void *),
+				 void *arg)
+{
+	struct __apk_qsort_r_compat_arg compat_arg = {
+		.compar = compar,
+		.arg = arg,
+	};
+	qsort_r(base, nmemb, size, &compat_arg, __apk_qsort_r_compar_compat);
+}
+#define qsort_r(...) __apk_qsort_r(__VA_ARGS__)
+#endif