1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
|
/// @file
/// @brief `qsort` with carried along context
/// @ingroup cgraph_utils
///
/// The non-standard `qsort_r`, Windows’ `qsort_s`, and C11’s `qsort_s` provide
/// a `qsort` alternative with an extra state parameter. Unfortunately none of
/// these are easily usable portably in Graphviz. This header implements an
/// alternative that hopefully is.
#pragma once
#include <assert.h>
#include <stdlib.h>
static _Thread_local int (*gv_sort_compar)(const void *, const void *, void *);
static _Thread_local void *gv_sort_arg;
static inline int gv_sort_compar_wrapper(const void *a, const void *b) {
assert(gv_sort_compar != NULL && "no comparator set in gv_sort");
return gv_sort_compar(a, b, gv_sort_arg);
}
/// `qsort` with an extra state parameter, ala `qsort_r`
static inline void gv_sort(void *base, size_t nmemb, size_t size,
int (*compar)(const void *, const void *, void *),
void *arg) {
assert(gv_sort_compar == NULL && gv_sort_arg == NULL &&
"unsupported recursive call to gv_sort");
gv_sort_compar = compar;
gv_sort_arg = arg;
if (nmemb > 1) {
qsort(base, nmemb, size, gv_sort_compar_wrapper);
}
gv_sort_compar = NULL;
gv_sort_arg = NULL;
}
|
