52 lines
1.5 KiB
C++
52 lines
1.5 KiB
C++
//===-- Unittests for rand ------------------------------------------------===//
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//
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// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
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// See https://llvm.org/LICENSE.txt for license information.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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//
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//===----------------------------------------------------------------------===//
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#include "src/stdlib/rand.h"
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#include "src/stdlib/srand.h"
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#include "test/UnitTest/Test.h"
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#include <stddef.h>
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TEST(LlvmLibcRandTest, UnsetSeed) {
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static int vals[1000];
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for (size_t i = 0; i < 1000; ++i) {
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int val = LIBC_NAMESPACE::rand();
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ASSERT_GE(val, 0);
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ASSERT_LE(val, RAND_MAX);
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vals[i] = val;
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}
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// The C standard specifies that if 'srand' is never called it should behave
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// as if 'srand' was called with a value of 1. If we seed the value with 1 we
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// should get the same sequence as the unseeded version.
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LIBC_NAMESPACE::srand(1);
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for (size_t i = 0; i < 1000; ++i)
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ASSERT_EQ(LIBC_NAMESPACE::rand(), vals[i]);
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}
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TEST(LlvmLibcRandTest, SetSeed) {
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const unsigned int SEED = 12344321;
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LIBC_NAMESPACE::srand(SEED);
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const size_t NUM_RESULTS = 10;
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int results[NUM_RESULTS];
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for (size_t i = 0; i < NUM_RESULTS; ++i) {
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results[i] = LIBC_NAMESPACE::rand();
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ASSERT_GE(results[i], 0);
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ASSERT_LE(results[i], RAND_MAX);
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}
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// If the seed is set to the same value, it should give the same sequence.
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LIBC_NAMESPACE::srand(SEED);
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for (size_t i = 0; i < NUM_RESULTS; ++i) {
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int val = LIBC_NAMESPACE::rand();
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EXPECT_EQ(results[i], val);
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}
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}
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