1 //===-- Unittests for stpncpy ---------------------------------------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 
9 #include "src/__support/CPP/ArrayRef.h"
10 #include "src/string/stpncpy.h"
11 #include "utils/UnitTest/Test.h"
12 #include <stddef.h> // For size_t.
13 
14 class LlvmLibcStpncpyTest : public __llvm_libc::testing::Test {
15 public:
16   void check_stpncpy(__llvm_libc::cpp::MutableArrayRef<char> dst,
17                      const __llvm_libc::cpp::ArrayRef<char> src, size_t n,
18                      const __llvm_libc::cpp::ArrayRef<char> expected,
19                      size_t expectedCopied) {
20     // Making sure we don't overflow buffer.
21     ASSERT_GE(dst.size(), n);
22     // Making sure stpncpy returns a pointer to the end of dst.
23     ASSERT_EQ(__llvm_libc::stpncpy(dst.data(), src.data(), n),
24               dst.data() + expectedCopied);
25     // Expected must be of the same size as dst.
26     ASSERT_EQ(dst.size(), expected.size());
27     // Expected and dst are the same.
28     for (size_t i = 0; i < expected.size(); ++i)
29       ASSERT_EQ(expected[i], dst[i]);
30   }
31 };
32 
33 TEST_F(LlvmLibcStpncpyTest, Untouched) {
34   char dst[] = {'a', 'b'};
35   const char src[] = {'x', '\0'};
36   const char expected[] = {'a', 'b'};
37   check_stpncpy(dst, src, 0, expected, 0);
38 }
39 
40 TEST_F(LlvmLibcStpncpyTest, CopyOne) {
41   char dst[] = {'a', 'b'};
42   const char src[] = {'x', 'y'};
43   const char expected[] = {'x', 'b'}; // no \0 is appended
44   check_stpncpy(dst, src, 1, expected, 1);
45 }
46 
47 TEST_F(LlvmLibcStpncpyTest, CopyNull) {
48   char dst[] = {'a', 'b'};
49   const char src[] = {'\0', 'y'};
50   const char expected[] = {'\0', 'b'};
51   check_stpncpy(dst, src, 1, expected, 0);
52 }
53 
54 TEST_F(LlvmLibcStpncpyTest, CopyPastSrc) {
55   char dst[] = {'a', 'b'};
56   const char src[] = {'\0', 'y'};
57   const char expected[] = {'\0', '\0'};
58   check_stpncpy(dst, src, 2, expected, 0);
59 }
60 
61 TEST_F(LlvmLibcStpncpyTest, CopyTwoNoNull) {
62   char dst[] = {'a', 'b'};
63   const char src[] = {'x', 'y'};
64   const char expected[] = {'x', 'y'};
65   check_stpncpy(dst, src, 2, expected, 2);
66 }
67 
68 TEST_F(LlvmLibcStpncpyTest, CopyTwoWithNull) {
69   char dst[] = {'a', 'b'};
70   const char src[] = {'x', '\0'};
71   const char expected[] = {'x', '\0'};
72   check_stpncpy(dst, src, 2, expected, 1);
73 }
74