etl/test/test_alignment.cpp

/******************************************************************************
The MIT License(MIT)

Embedded Template Library.
https://github.com/ETLCPP/etl
https://www.etlcpp.com

Copyright(c) 2014 John Wellbelove

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files(the "Software"), to deal
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IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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******************************************************************************/

#include "unit_test_framework.h"

#include "etl/alignment.h"
#include "etl/type_traits.h"

#include <type_traits>
#include <utility>
#include <string>
#include <ostream>

#if defined(ETL_COMPILER_MICROSOFT)
  #pragma warning(disable : 4996)
#endif

#ifdef ETL_COMPILER_GCC
  #pragma GCC diagnostic ignored "-Wdeprecated-declarations"
#endif

void f(int)
{
}

// Demonstrator class for etl::typed_storage tests
struct A_t
{
  A_t(uint32_t v_x, uint8_t v_y)
   : x(v_x)
   , y(v_y)
  {
  }

  // Just for test purpose. In production code, etl::typed_storage
  // actually supports the use case of destructors being optimized
  // away since they are not necessary for global objects that are
  // never destroyed
  ~A_t()
  {
    x = 0;
    y = 0;
  }

  // etl::typed_storage helps implementing the use case of becoming
  // independent of the destructor. By deleting the assignment operator,
  // we make sure that the destructor is not linked
  A_t& operator=(const A_t&) = delete;

  bool operator==(const A_t& other) const
  {
    return other.x == x && other.y == y;
  }

  uint32_t x;
  uint8_t y;
};

namespace
{
  SUITE(test_alignment)
  {
    //*************************************************************************
    TEST(test_aligned_storage)
    {
      size_t alignment;
      size_t expected;

      typedef etl::aligned_storage<sizeof(uint16_t), etl::alignment_of<uint32_t>::value>::type storage32_t;
      static storage32_t data32[10];

      alignment = etl::alignment_of<storage32_t>::value;
      expected  = std::alignment_of<uint32_t>::value;

      CHECK_EQUAL(expected, alignment);

      for (int i = 0; i < 10; ++i)
      {
        CHECK_EQUAL(0U, size_t(&data32[1]) % expected);
      }

      etl::aligned_storage<100, 8>::type data9;
      f(static_cast<int>(data9));
    }

    //*************************************************************************
    TEST(test_aligned_storage_conversion_operators)
    {
      typedef etl::aligned_storage<sizeof(uint32_t), etl::alignment_of<uint32_t>::value>::type storage32_t;
      static storage32_t data;

      void* pdata = &data.data;

      uint32_t& ref        = data;
      const uint32_t& cref = data;
      CHECK(&ref  == pdata);
      CHECK(&cref == pdata);

      uint32_t* ptr        = data;
      const uint32_t* cptr = data;
      CHECK(ptr  == pdata);
      CHECK(cptr == pdata);

      uint32_t& ref2        = data.get_reference<uint32_t>();
      const uint32_t& cref2 = data.get_reference<const uint32_t>();
      CHECK(&ref2  == pdata);
      CHECK(&cref2 == pdata);
      
      uint32_t* ptr2        = data.get_address<uint32_t>();
      const uint32_t* cptr2 = data.get_address<const uint32_t>();
      CHECK(ptr2  == pdata);
      CHECK(cptr2 == pdata);
    }

    //*************************************************************************
    TEST(test_aligned_storage_as)
    {
      size_t alignment;
      size_t expected;

      typedef etl::aligned_storage_as<sizeof(uint16_t), uint32_t>::type storage32_t;
      static storage32_t data32[10];

      alignment = etl::alignment_of<storage32_t>::value;
      expected = std::alignment_of<uint32_t>::value;

      CHECK_EQUAL(expected, alignment);

      for (int i = 0; i < 10; ++i)
      {
        CHECK_EQUAL(0U, size_t(&data32[1]) % expected);
      }

      etl::aligned_storage<100, 8>::type data9;
      f(static_cast<int>(data9));
    }

    //*************************************************************************
    TEST(test_is_aligned_tests)
    {
      alignas(uint32_t) char buffer[2U * sizeof(uint32_t)];

      char* p = buffer;

      CHECK_TRUE(etl::is_aligned(p, std::alignment_of<uint32_t>()));
      CHECK_TRUE(etl::is_aligned<alignof(uint32_t)>(p));
      CHECK_TRUE(etl::is_aligned<uint32_t>(p));

      ++p;
      CHECK_FALSE(etl::is_aligned(p, std::alignment_of<uint32_t>()));
      CHECK_FALSE(etl::is_aligned<alignof(uint32_t)>(p));
      CHECK_FALSE(etl::is_aligned<uint32_t>(p));
    }

    //*************************************************************************
    TEST(test_is_aligned_tests_const)
    {
      alignas(uint32_t) const char buffer[2U * sizeof(uint32_t)] = {0, 1};

      const char* p = buffer;

      CHECK_TRUE(etl::is_aligned(p, std::alignment_of<const uint32_t>()));
      CHECK_TRUE(etl::is_aligned<alignof(const uint32_t)>(p));
      CHECK_TRUE(etl::is_aligned<const uint32_t>(p));

      ++p;
      CHECK_FALSE(etl::is_aligned(p, std::alignment_of<const uint32_t>()));
      CHECK_FALSE(etl::is_aligned<alignof(const uint32_t)>(p));
      CHECK_FALSE(etl::is_aligned<const uint32_t>(p));
    }

    //*************************************************************************
    TEST(test_type_with_alignment)
    {
      CHECK_EQUAL(1,  alignof(etl::type_with_alignment_t<1>));
      CHECK_EQUAL(2,  alignof(etl::type_with_alignment_t<2>));
      CHECK_EQUAL(4,  alignof(etl::type_with_alignment_t<4>));
      CHECK_EQUAL(8,  alignof(etl::type_with_alignment_t<8>));
      CHECK_EQUAL(16, alignof(etl::type_with_alignment_t<16>));
      CHECK_EQUAL(32, alignof(etl::type_with_alignment_t<32>));
      CHECK_EQUAL(64, alignof(etl::type_with_alignment_t<64>));
    }

    //*************************************************************************
    TEST(test_typed_storage)
    {
      etl::typed_storage<A_t> a;
      CHECK_FALSE(a.has_value());

      // Construct in place.
      etl::typed_storage<A_t> b(789, 10);  
      CHECK_TRUE(b.has_value());
      CHECK_EQUAL(b->x, 789);
      CHECK_EQUAL(b->y, 10);
      
      // Create in place.
      auto& ref = a.create(123, 4);
      CHECK_TRUE(a.has_value());

      CHECK_EQUAL(a->x, 123);
      CHECK_EQUAL(a->y, 4);

      CHECK_EQUAL(ref.x, 123);
      CHECK_EQUAL(ref.y, 4);

      CHECK_TRUE(*a == ref);

      // Destroy
      CHECK_TRUE(a.has_value());
      a.destroy();
      CHECK_FALSE(a.has_value());
    }

    //*************************************************************************
    TEST(test_typed_storage_ext)
    {
      alignas(A_t) char buffer1[sizeof(A_t)] = {0};
      alignas(A_t) char buffer2[sizeof(A_t)] = {0};

      // Construct.
      etl::typed_storage_ext<A_t> a(buffer1);
      CHECK_FALSE(a.has_value());

      // Construct in place.
      etl::typed_storage_ext<A_t> b(buffer2, 789, 10);
      CHECK_TRUE(b.has_value());
      CHECK_EQUAL(b->x, 789);
      CHECK_EQUAL(b->y, 10);

      // Create in place.
      auto& ref = a.create(123, 4);  
      CHECK_EQUAL(ref.x, 123);
      CHECK_EQUAL(ref.y, 4);

      CHECK_TRUE(a.has_value());
      CHECK_EQUAL(a->x, 123);
      CHECK_EQUAL(a->y, 4);
      CHECK_TRUE(*a == ref);

      // Swap
      etl::swap(a, b);
      CHECK_TRUE(a.has_value());
      CHECK_EQUAL(a->x, 789);
      CHECK_EQUAL(a->y, 10);

      CHECK_TRUE(b.has_value());
      CHECK_EQUAL(b->x, 123);
      CHECK_EQUAL(b->y, 4);

      // Move contruct
      etl::typed_storage_ext<A_t> c(etl::move(a));
      CHECK_FALSE(a.has_value());
      CHECK_TRUE(c.has_value());
      CHECK_EQUAL(c->x, 789);
      CHECK_EQUAL(c->y, 10);

      // Destroy
      CHECK_TRUE(c.has_value());
      c.destroy();
      CHECK_FALSE(c.has_value());
    }
  };
}