libc/test/src/string/stpncpy_test.cpp

   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/span.h"
  10 #include "src/string/stpncpy.h"
  11 #include "test/UnitTest/Test.h"
  12 #include <stddef.h> // For size_t.
  13
  14 class LlvmLibcStpncpyTest : public LIBC_NAMESPACE::testing::Test {
  15 public:
  16   void check_stpncpy(LIBC_NAMESPACE::cpp::span<char> dst,
  17                      const LIBC_NAMESPACE::cpp::span<const char> src, size_t n,
  18                      const LIBC_NAMESPACE::cpp::span<const 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(LIBC_NAMESPACE::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 }