libc/test/src/string/memmove_test.cpp

   1 //===-- Unittests for memmove ---------------------------------------------===//
   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/string/memmove.h"
  10
  11 #include "memory_utils/memory_check_utils.h"
  12 #include "src/__support/CPP/span.h"
  13 #include "test/UnitTest/MemoryMatcher.h"
  14 #include "test/UnitTest/Test.h"
  15
  16 using __llvm_libc::cpp::array;
  17 using __llvm_libc::cpp::span;
  18
  19 namespace __llvm_libc {
  20
  21 TEST(LlvmLibcMemmoveTest, MoveZeroByte) {
  22   char Buffer[] = {'a', 'b', 'y', 'z'};
  23   const char Expected[] = {'a', 'b', 'y', 'z'};
  24   void *const Dst = Buffer;
  25   void *const Ret = __llvm_libc::memmove(Dst, Buffer + 2, 0);
  26   EXPECT_EQ(Ret, Dst);
  27   ASSERT_MEM_EQ(Buffer, testing::MemoryView(Expected));
  28 }
  29
  30 TEST(LlvmLibcMemmoveTest, DstAndSrcPointToSameAddress) {
  31   char Buffer[] = {'a', 'b'};
  32   const char Expected[] = {'a', 'b'};
  33   void *const Dst = Buffer;
  34   void *const Ret = __llvm_libc::memmove(Dst, Buffer, 1);
  35   EXPECT_EQ(Ret, Dst);
  36   ASSERT_MEM_EQ(Buffer, testing::MemoryView(Expected));
  37 }
  38
  39 TEST(LlvmLibcMemmoveTest, DstStartsBeforeSrc) {
  40   // Set boundary at beginning and end for not overstepping when
  41   // copy forward or backward.
  42   char Buffer[] = {'z', 'a', 'b', 'c', 'z'};
  43   const char Expected[] = {'z', 'b', 'c', 'c', 'z'};
  44   void *const Dst = Buffer + 1;
  45   void *const Ret = __llvm_libc::memmove(Dst, Buffer + 2, 2);
  46   EXPECT_EQ(Ret, Dst);
  47   ASSERT_MEM_EQ(Buffer, testing::MemoryView(Expected));
  48 }
  49
  50 TEST(LlvmLibcMemmoveTest, DstStartsAfterSrc) {
  51   char Buffer[] = {'z', 'a', 'b', 'c', 'z'};
  52   const char Expected[] = {'z', 'a', 'a', 'b', 'z'};
  53   void *const Dst = Buffer + 2;
  54   void *const Ret = __llvm_libc::memmove(Dst, Buffer + 1, 2);
  55   EXPECT_EQ(Ret, Dst);
  56   ASSERT_MEM_EQ(Buffer, testing::MemoryView(Expected));
  57 }
  58
  59 // e.g. `Dst` follow `src`.
  60 // str: [abcdefghij]
  61 //      [__src_____]
  62 //      [_____Dst__]
  63 TEST(LlvmLibcMemmoveTest, SrcFollowDst) {
  64   char Buffer[] = {'z', 'a', 'b', 'z'};
  65   const char Expected[] = {'z', 'b', 'b', 'z'};
  66   void *const Dst = Buffer + 1;
  67   void *const Ret = __llvm_libc::memmove(Dst, Buffer + 2, 1);
  68   EXPECT_EQ(Ret, Dst);
  69   ASSERT_MEM_EQ(Buffer, testing::MemoryView(Expected));
  70 }
  71
  72 TEST(LlvmLibcMemmoveTest, DstFollowSrc) {
  73   char Buffer[] = {'z', 'a', 'b', 'z'};
  74   const char Expected[] = {'z', 'a', 'a', 'z'};
  75   void *const Dst = Buffer + 2;
  76   void *const Ret = __llvm_libc::memmove(Dst, Buffer + 1, 1);
  77   EXPECT_EQ(Ret, Dst);
  78   ASSERT_MEM_EQ(Buffer, testing::MemoryView(Expected));
  79 }
  80
  81 // Adapt CheckMemmove signature to op implementation signatures.
  82 static inline void Adaptor(cpp::span<char> dst, cpp::span<char> src,
  83                            size_t size) {
  84   __llvm_libc::memmove(dst.begin(), src.begin(), size);
  85 }
  86
  87 TEST(LlvmLibcMemmoveTest, SizeSweep) {
  88   static constexpr int kMaxSize = 400;
  89   static constexpr int kDenseOverlap = 15;
  90   using LargeBuffer = array<char, 2 * kMaxSize + 1>;
  91   LargeBuffer Buffer;
  92   Randomize(Buffer);
  93   for (int Size = 0; Size < kMaxSize; ++Size)
  94     for (int Overlap = -1; Overlap < Size;) {
  95       ASSERT_TRUE(CheckMemmove<Adaptor>(Buffer, Size, Overlap));
  96       // Prevent quadratic behavior by skipping offset above kDenseOverlap.
  97       if (Overlap > kDenseOverlap)
  98         Overlap *= 2;
  99       else
 100         ++Overlap;
 101     }
 102 }
 103
 104 } // namespace __llvm_libc