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      1 /*
      2  * Copyright (C) 2016 The Android Open Source Project
      3  *
      4  * Licensed under the Apache License, Version 2.0 (the "License");
      5  * you may not use this file except in compliance with the License.
      6  * You may obtain a copy of the License at
      7  *
      8  *      http://www.apache.org/licenses/LICENSE-2.0
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an "AS IS" BASIS,
     12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13  * See the License for the specific language governing permissions and
     14  * limitations under the License.
     15  */
     16 
     17 #include <shared/nano_endian.h>
     18 
     19 #include <cstdint>
     20 #include <cstring>
     21 
     22 #include <gtest/gtest.h>
     23 #include <shared/array_length.h>
     24 
     25 
     26 template<size_t kByteCount>
     27 static void swapByteTest() {
     28   uint8_t bytes[] = {
     29     0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08,
     30     0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E, 0x0F, 0x10 };
     31   static constexpr uint8_t postSwap[] = {
     32     0x10, 0x0F, 0x0E, 0x0D, 0x0C, 0x0B, 0x0A, 0x09,
     33     0x08, 0x07, 0x06, 0x05, 0x04, 0x03, 0x02, 0x01 };
     34 
     35 #ifdef __clang__
     36   // This static_assert crashes g++, but it's legit and works in clang.
     37   static_assert(arrayLength(bytes) == arrayLength(postSwap),
     38                 "Mismatched arrays");
     39 #endif
     40   static_assert((kByteCount > 0) && (kByteCount <= arrayLength(bytes)),
     41                 "Invalid test");
     42 
     43   constexpr const uint8_t *kExpected =
     44       postSwap + (arrayLength(postSwap) - kByteCount);
     45   nanoapp_testing::swapBytes(bytes, kByteCount);
     46   EXPECT_EQ(0, ::memcmp(bytes, kExpected, kByteCount));
     47 
     48   if (arrayLength(bytes) < kByteCount) {
     49     // Confirm that we didn't modify out of bounds.
     50     EXPECT_EQ(kByteCount + 1, bytes[kByteCount]);
     51   }
     52 }
     53 
     54 
     55 TEST(EndianTest, SwapBytes1) {
     56   swapByteTest<1>();
     57 }
     58 
     59 TEST(EndianTest, SwapBytes2) {
     60   swapByteTest<2>();
     61 }
     62 
     63 TEST(EndianTest, SwapBytes4) {
     64   swapByteTest<4>();
     65 }
     66 
     67 TEST(EndianTest, SwapBytes8) {
     68   swapByteTest<8>();
     69 }
     70 
     71 TEST(EndianTest, SwapBytes16) {
     72   swapByteTest<16>();
     73 }
     74 
     75 
     76 // These tests should work regardless of which endian platform this
     77 // test happens to be built and running on.
     78 
     79 static constexpr uint32_t kValue = UINT32_C(0x04030201);
     80 static constexpr uint8_t kLittleEndianRepresentation[4] = {
     81   0x01, 0x02, 0x03, 0x04 };
     82 
     83 TEST(EndianTest, LittleEndianToHost) {
     84   uint32_t value;
     85   ::memcpy(&value, kLittleEndianRepresentation, sizeof(value));
     86 
     87   value = nanoapp_testing::littleEndianToHost(value);
     88   EXPECT_EQ(kValue, value);
     89 }
     90 
     91 TEST(EndianTest, HostToLittleEndian) {
     92   uint32_t value = kValue;
     93   value = nanoapp_testing::hostToLittleEndian(value);
     94 
     95   const uint8_t *bytes = reinterpret_cast<uint8_t*>(&value);
     96   EXPECT_EQ(0, ::memcmp(kLittleEndianRepresentation, bytes,
     97                         sizeof(kLittleEndianRepresentation)));
     98 }
     99