1 files changed, 78 insertions, 0 deletions
diff --git a/src/basic/sort-util.h b/src/basic/sort-util.h
new file mode 100644
index 0000000..45f05bb
--- /dev/null
+++ b/src/basic/sort-util.h
@@ -0,0 +1,78 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+#pragma once
+
+#include <stdlib.h>
+
+#include "macro.h"
+
+/* This is the same as glibc's internal __compar_d_fn_t type. glibc exports a public comparison_fn_t, for the
+ * external type __compar_fn_t, but doesn't do anything similar for __compar_d_fn_t. Let's hence do that
+ * ourselves, picking a name that is obvious, but likely enough to not clash with glibc's choice of naming if
+ * they should ever add one. */
+typedef int (*comparison_userdata_fn_t)(const void *, const void *, void *);
+
+void *xbsearch_r(const void *key, const void *base, size_t nmemb, size_t size,
+                 comparison_userdata_fn_t compar, void *arg);
+
+#define typesafe_bsearch_r(k, b, n, func, userdata)                     \
+        ({                                                              \
+                const typeof((b)[0]) *_k = k;                           \
+                int (*_func_)(const typeof((b)[0])*, const typeof((b)[0])*, typeof(userdata)) = func; \
+                (typeof((b)[0])*) xbsearch_r((const void*) _k, (b), (n), sizeof((b)[0]), (comparison_userdata_fn_t) _func_, userdata); \
+        })
+
+/**
+ * Normal bsearch requires base to be nonnull. Here were require
+ * that only if nmemb > 0.
+ */
+static inline void* bsearch_safe(const void *key, const void *base,
+                                 size_t nmemb, size_t size, comparison_fn_t compar) {
+        if (nmemb <= 0)
+                return NULL;
+
+        assert(base);
+        return bsearch(key, base, nmemb, size, compar);
+}
+
+#define typesafe_bsearch(k, b, n, func)                                 \
+        ({                                                              \
+                const typeof((b)[0]) *_k = k;                           \
+                int (*_func_)(const typeof((b)[0])*, const typeof((b)[0])*) = func; \
+                (typeof((b)[0])*) bsearch_safe((const void*) _k, (b), (n), sizeof((b)[0]), (comparison_fn_t) _func_); \
+        })
+
+/**
+ * Normal qsort requires base to be nonnull. Here were require
+ * that only if nmemb > 0.
+ */
+static inline void _qsort_safe(void *base, size_t nmemb, size_t size, comparison_fn_t compar) {
+        if (nmemb <= 1)
+                return;
+
+        assert(base);
+        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]), (comparison_fn_t) _func_); \
+        })
+
+static inline void qsort_r_safe(void *base, size_t nmemb, size_t size, comparison_userdata_fn_t compar, void *userdata) {
+        if (nmemb <= 1)
+                return;
+
+        assert(base);
+        qsort_r(base, nmemb, size, compar, userdata);
+}
+
+#define typesafe_qsort_r(p, n, func, userdata)                          \
+        ({                                                              \
+                int (*_func_)(const typeof((p)[0])*, const typeof((p)[0])*, typeof(userdata)) = func; \
+                qsort_r_safe((p), (n), sizeof((p)[0]), (comparison_userdata_fn_t) _func_, userdata); \
+        })
+
+int cmp_int(const int *a, const int *b);