74 lines · cpp
1// Check that a qsort() comparator that calls qsort() works as expected2// RUN: %clangxx -O2 %s -o %t3// RUN: %run %t 2>&1 | FileCheck %s4 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 recursion21 qsort(global_array, array_size(global_array), sizeof(int), &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("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(&f1->array, array_size(f1->array), sizeof(int), &descending_compare_ints);32 qsort(&f2->array, array_size(f2->array), sizeof(int), &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 struct58 // Foo array in ascending order of the second array element.59 qsort(qsortArg, array_size(qsortArg), sizeof(qsortArg[0]), &sort_and_compare);60 61 printf("Sorted result:");62 for (const auto &f : qsortArg) {63 printf(" {%d,%d}", f.array[0], f.array[1]);64 }65 printf("\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("Sorted global_array:");68 for (int i : global_array) {69 printf(" %d", i);70 }71 printf("\n");72 // CHECK: Sorted global_array: 1 2 3 4 5 6 7 8 9 10 11 1273}74