1// Check that a qsort() comparator that calls qsort() works as expected
2// RUN: %clangxx -O2 %s -o %t
3// RUN: %run %t 2>&1 | FileCheck %s
4
5#include <stdio.h>
6#include <stdlib.h>
7
8struct Foo {
9 int array[2];
10};
11int global_array[12] = {7, 11, 9, 10, 1, 2, 4, 3, 6, 5, 8, 12};
12
13#define array_size(x) (sizeof(x) / sizeof(x[0]))
14
15int ascending_compare_ints(const void *a, const void *b) {
16 return *(const int *)a - *(const int *)b;
17}
18
19int descending_compare_ints(const void *a, const void *b) {
20 // Add another qsort() call to check more than one level of recursion
21 qsort(base: global_array, array_size(global_array), size: sizeof(int), compar: &ascending_compare_ints);
22 return *(const int *)b - *(const int *)a;
23}
24
25int sort_and_compare(const void *a, const void *b) {
26 struct Foo *f1 = (struct Foo *)a;
27 struct Foo *f2 = (struct Foo *)b;
28 printf(format: "sort_and_compare({%d, %d}, {%d, %d})\n", f1->array[0], f1->array[1],
29 f2->array[0], f2->array[1]);
30 // Call qsort from within qsort() to check that interceptors handle this case:
31 qsort(base: &f1->array, array_size(f1->array), size: sizeof(int), compar: &descending_compare_ints);
32 qsort(base: &f2->array, array_size(f2->array), size: sizeof(int), compar: &descending_compare_ints);
33 // Sort by second array element:
34 return f1->array[1] - f2->array[1];
35}
36
37int main() {
38 // Note: 16 elements should be large enough to trigger a recursive qsort() call.
39 struct Foo qsortArg[16] = {
40 {1, 99},
41 {2, 3},
42 {17, 5},
43 {8, 6},
44 {11, 4},
45 {3, 3},
46 {16, 17},
47 {7, 9},
48 {21, 12},
49 {32, 23},
50 {13, 8},
51 {99, 98},
52 {41, 42},
53 {42, 43},
54 {44, 45},
55 {0, 1},
56 };
57 // Sort the individual arrays in descending order and the over all struct
58 // Foo array in ascending order of the second array element.
59 qsort(base: qsortArg, array_size(qsortArg), size: sizeof(qsortArg[0]), compar: &sort_and_compare);
60
61 printf(format: "Sorted result:");
62 for (const auto &f : qsortArg) {
63 printf(format: " {%d,%d}", f.array[0], f.array[1]);
64 }
65 printf(format: "\n");
66 // CHECK: Sorted result: {1,0} {99,1} {3,2} {3,3} {11,4} {17,5} {8,6} {9,7} {13,8} {21,12} {17,16} {32,23} {42,41} {43,42} {45,44} {99,98}
67 printf(format: "Sorted global_array:");
68 for (int i : global_array) {
69 printf(format: " %d", i);
70 }
71 printf(format: "\n");
72 // CHECK: Sorted global_array: 1 2 3 4 5 6 7 8 9 10 11 12
73}
74

source code of compiler-rt/test/sanitizer_common/TestCases/Posix/recursion-in-qsort.cpp