llvm/libc/test/src/stdlib/qsort_r_test.cpp

//===-- Unittests for qsort_r ---------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//

#include "src/stdlib/qsort_r.h"

#include "test/UnitTest/Test.h"

#include <stdlib.h>

static int int_compare_count(const void *l, const void *r, void *count_arg) { … }

TEST(LlvmLibcQsortRTest, SortedArray) { … }

TEST(LlvmLibcQsortRTest, ReverseSortedArray) { … }

// The following test is intended to mimic the CPP library pattern of having a
// comparison function that takes a specific type, which is passed to a library
// that then needs to sort an array of that type. The library can't safely pass
// the comparison function to qsort because a function that takes const T*
// being cast to a function that takes const void* is undefined behavior. The
// safer pattern is to pass a type erased comparator that calls into the typed
// comparator to qsort_r.

struct PriorityVal { … };

static int compare_priority_val(const PriorityVal *l, const PriorityVal *r) { … }

template <typename T>
static int type_erased_comp(const void *l, const void *r,
                            void *erased_func_ptr) { … }

TEST(LlvmLibcQsortRTest, SafeTypeErasure) { … }