Allow compile time CRC calculation (#1016)

* Making crc constexpr for c++14. Allows compile time CRC computation. * Fix syntax when using c++03 or `ETL_FORCE_NO_ADVANCED_CPP` * Remove use of `ETL_FORCE_NO_ADVANCED_CPP` option since it is no longer used. --------- Co-authored-by: Zach O'Brien <[email protected]> Co-authored-by: John Wellbelove <[email protected]>
ETLCPP · Jan 24, 2025 · 14b50c6 · 14b50c6
1 parent 778351a
commit 14b50c6
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Showing 50 changed files with 1,610 additions and 21 deletions.
diff --git a/include/etl/frame_check_sequence.h b/include/etl/frame_check_sequence.h
@@ -107,7 +107,7 @@ namespace etl
     //*************************************************************************
     /// Default constructor.
     //*************************************************************************
-    frame_check_sequence()
+    ETL_CONSTEXPR14 frame_check_sequence() : frame_check()
     {
       reset();
     }
@@ -118,7 +118,7 @@ namespace etl
     /// \param end   End of the range.
     //*************************************************************************
     template<typename TIterator>
-    frame_check_sequence(TIterator begin, const TIterator end)
+    ETL_CONSTEXPR14 frame_check_sequence(TIterator begin, const TIterator end) : frame_check()
     {
       ETL_STATIC_ASSERT(sizeof(typename etl::iterator_traits<TIterator>::value_type) == 1, "Type not supported");
 
@@ -129,7 +129,7 @@ namespace etl
     //*************************************************************************
     /// Resets the FCS to the initial state.
     //*************************************************************************
-    void reset()
+    ETL_CONSTEXPR14 void reset()
     {
       frame_check = policy.initial();
     }
@@ -140,7 +140,7 @@ namespace etl
     /// \param end
     //*************************************************************************
     template<typename TIterator>
-    void add(TIterator begin, const TIterator end)
+    ETL_CONSTEXPR14 void add(TIterator begin, const TIterator end)
     {
       ETL_STATIC_ASSERT(sizeof(typename etl::iterator_traits<TIterator>::value_type) == 1, "Type not supported");
 
@@ -154,31 +154,31 @@ namespace etl
     //*************************************************************************
     /// \param value The uint8_t to add to the FCS.
     //*************************************************************************
-    void add(uint8_t value_)
+    ETL_CONSTEXPR14 void add(uint8_t value_)
     {
       frame_check = policy.add(frame_check, value_);
     }
 
     //*************************************************************************
     /// Gets the FCS value.
     //*************************************************************************
-    value_type value() const
+    ETL_CONSTEXPR14 value_type value() const
     {
       return policy.final(frame_check);
     }
 
     //*************************************************************************
     /// Conversion operator to value_type.
     //*************************************************************************
-    operator value_type () const
+    ETL_CONSTEXPR14 operator value_type () const
     {
       return policy.final(frame_check);
     }
 
     //*************************************************************************
     /// Gets an add_insert_iterator for input.
     //*************************************************************************
-    add_insert_iterator input()
+    ETL_CONSTEXPR14 add_insert_iterator input()
     {
       return add_insert_iterator(*this);
     }

diff --git a/include/etl/private/crc_implementation.h b/include/etl/private/crc_implementation.h
@@ -163,7 +163,7 @@ namespace etl
     // Accumulator_Bits > Chunk_Bits
     // Not Reflected
     template <typename TAccumulator, size_t Accumulator_Bits, size_t Chunk_Bits, uint8_t Chunk_Mask, bool Reflect>
-    static
+    static ETL_CONSTEXPR14
     typename etl::enable_if<(Accumulator_Bits > Chunk_Bits) && !Reflect, TAccumulator>::type
       crc_update_chunk(TAccumulator crc, uint8_t value, const TAccumulator table[])
     {
@@ -181,7 +181,7 @@ namespace etl
     // Accumulator_Bits > Chunk_Bits
     // Reflected
     template <typename TAccumulator, size_t Accumulator_Bits, size_t Chunk_Bits, uint8_t Chunk_Mask, bool Reflect>
-    static
+    static ETL_CONSTEXPR14
     typename etl::enable_if<(Accumulator_Bits > Chunk_Bits) && Reflect, TAccumulator>::type
       crc_update_chunk(TAccumulator crc, uint8_t value, const TAccumulator table[])
     {
@@ -199,7 +199,7 @@ namespace etl
     // Accumulator_Bits == Chunk_Bits
     // Not Reflected
     template <typename TAccumulator, size_t Accumulator_Bits, size_t Chunk_Bits, uint8_t Chunk_Mask, bool Reflect>
-    static
+    static ETL_CONSTEXPR14
     typename etl::enable_if<(Accumulator_Bits == Chunk_Bits) && !Reflect, TAccumulator>::type
       crc_update_chunk(TAccumulator crc, uint8_t value, const TAccumulator table[])
     {
@@ -216,7 +216,7 @@ namespace etl
     // Accumulator_Bits == Chunk_Bits
     // Reflected
     template <typename TAccumulator, size_t Accumulator_Bits, size_t Chunk_Bits, uint8_t Chunk_Mask, bool Reflect>
-    static
+    static ETL_CONSTEXPR14
     typename etl::enable_if<(Accumulator_Bits == Chunk_Bits) && Reflect, TAccumulator>::type
       crc_update_chunk(TAccumulator crc, uint8_t value, const TAccumulator table[])
     {
@@ -241,16 +241,21 @@ namespace etl
     struct crc_table<TAccumulator, Accumulator_Bits, Chunk_Bits, Chunk_Mask, Polynomial, Reflect, 4U>
     {
       //*************************************************************************
+#if !ETL_USING_CPP11
       TAccumulator add(TAccumulator crc, uint8_t value) const
       {
+#endif
         static ETL_CONSTANT TAccumulator table[4U] =
         {
           crc_table_entry<TAccumulator, Accumulator_Bits, Polynomial, Reflect, 0U, Chunk_Bits>::value,
           crc_table_entry<TAccumulator, Accumulator_Bits, Polynomial, Reflect, 1U, Chunk_Bits>::value,
           crc_table_entry<TAccumulator, Accumulator_Bits, Polynomial, Reflect, 2U, Chunk_Bits>::value,
           crc_table_entry<TAccumulator, Accumulator_Bits, Polynomial, Reflect, 3U, Chunk_Bits>::value
         };
-
+#if ETL_USING_CPP11
+      ETL_CONSTEXPR14 TAccumulator add(TAccumulator crc, uint8_t value) const
+      {
+#endif
         if ETL_IF_CONSTEXPR(Reflect)
         {
           crc = crc_update_chunk<TAccumulator, Accumulator_Bits, Chunk_Bits, Chunk_Mask, Reflect>(crc, value, table);
@@ -269,15 +274,21 @@ namespace etl
         return crc;
       }
     };
+#if ETL_USING_CPP11
+    template <typename TAccumulator, size_t Accumulator_Bits, size_t Chunk_Bits, uint8_t Chunk_Mask, TAccumulator Polynomial, bool Reflect>
+    ETL_CONSTANT TAccumulator crc_table<TAccumulator, Accumulator_Bits, Chunk_Bits, Chunk_Mask, Polynomial, Reflect, 4U>::table[4U];
+#endif
 
     //*********************************
     // Table size of 16.
     template <typename TAccumulator, size_t Accumulator_Bits, size_t Chunk_Bits, uint8_t Chunk_Mask, TAccumulator Polynomial, bool Reflect>
     struct crc_table<TAccumulator, Accumulator_Bits, Chunk_Bits, Chunk_Mask, Polynomial, Reflect, 16U>
     {
       //*************************************************************************
+#if !ETL_USING_CPP11
       TAccumulator add(TAccumulator crc, uint8_t value) const
       {
+#endif
         static ETL_CONSTANT TAccumulator table[16U] =
         {
           crc_table_entry<TAccumulator, Accumulator_Bits, Polynomial, Reflect, 0U, Chunk_Bits>::value,
@@ -297,7 +308,10 @@ namespace etl
           crc_table_entry<TAccumulator, Accumulator_Bits, Polynomial, Reflect, 14U, Chunk_Bits>::value,
           crc_table_entry<TAccumulator, Accumulator_Bits, Polynomial, Reflect, 15U, Chunk_Bits>::value
         };
-
+#if ETL_USING_CPP11
+      ETL_CONSTEXPR14 TAccumulator add(TAccumulator crc, uint8_t value) const
+      {
+#endif
         if ETL_IF_CONSTEXPR(Reflect)
         {
           crc = crc_update_chunk<TAccumulator, Accumulator_Bits, Chunk_Bits, Chunk_Mask, Reflect>(crc, value, table);
@@ -312,16 +326,22 @@ namespace etl
         return crc;
       }
     };
+#if ETL_USING_CPP11
+    template <typename TAccumulator, size_t Accumulator_Bits, size_t Chunk_Bits, uint8_t Chunk_Mask, TAccumulator Polynomial, bool Reflect>
+    ETL_CONSTANT TAccumulator crc_table<TAccumulator, Accumulator_Bits, Chunk_Bits, Chunk_Mask, Polynomial, Reflect, 16U>::table[16U];
+#endif
 
     //*********************************
     // Table size of 256.
     template <typename TAccumulator, size_t Accumulator_Bits, size_t Chunk_Bits, uint8_t Chunk_Mask, TAccumulator Polynomial, bool Reflect>
     struct crc_table<TAccumulator, Accumulator_Bits, Chunk_Bits, Chunk_Mask, Polynomial, Reflect, 256U>
     {
       //*************************************************************************
+#if !ETL_USING_CPP11
       TAccumulator add(TAccumulator crc, uint8_t value) const
       {
-        static ETL_CONSTANT TAccumulator table[256U] =
+#endif
+        static ETL_CONSTANT TAccumulator table[256U]=
         {
           crc_table_entry<TAccumulator, Accumulator_Bits, Polynomial, Reflect, 0U, Chunk_Bits>::value,
           crc_table_entry<TAccumulator, Accumulator_Bits, Polynomial, Reflect, 1U, Chunk_Bits>::value,
@@ -580,13 +600,20 @@ namespace etl
           crc_table_entry<TAccumulator, Accumulator_Bits, Polynomial, Reflect, 254U, Chunk_Bits>::value,
           crc_table_entry<TAccumulator, Accumulator_Bits, Polynomial, Reflect, 255U, Chunk_Bits>::value
         };
+#if ETL_USING_CPP11
+      ETL_CONSTEXPR14 TAccumulator add(TAccumulator crc, uint8_t value) const
+      {
+#endif
 
         crc = crc_update_chunk<TAccumulator, Accumulator_Bits, Chunk_Bits, Chunk_Mask, Reflect>(crc, value, table);
 
         return crc;
       }
     };
-
+#if ETL_USING_CPP11
+    template <typename TAccumulator, size_t Accumulator_Bits, size_t Chunk_Bits, uint8_t Chunk_Mask, TAccumulator Polynomial, bool Reflect>
+    ETL_CONSTANT TAccumulator crc_table<TAccumulator, Accumulator_Bits, Chunk_Bits, Chunk_Mask, Polynomial, Reflect, 256U>::table[256U];
+#endif
     //*****************************************************************************
     // CRC Policies.
     //*****************************************************************************
@@ -615,7 +642,7 @@ namespace etl
       }
 
       //*************************************************************************
-      accumulator_type final(accumulator_type crc) const
+      ETL_CONSTEXPR accumulator_type final(accumulator_type crc) const
       {
         return crc ^ TCrcParameters::Xor_Out;
       }
@@ -643,7 +670,7 @@ namespace etl
       }
 
       //*************************************************************************
-      accumulator_type final(accumulator_type crc) const
+      ETL_CONSTEXPR accumulator_type final(accumulator_type crc) const
       {
         return crc ^ TCrcParameters::Xor_Out;
       }
@@ -671,7 +698,7 @@ namespace etl
       }
 
       //*************************************************************************
-      accumulator_type final(accumulator_type crc) const
+      ETL_CONSTEXPR accumulator_type final(accumulator_type crc) const
       {
         return crc ^ TCrcParameters::Xor_Out;
       }
@@ -691,7 +718,7 @@ namespace etl
     //*************************************************************************
     /// Default constructor.
     //*************************************************************************
-    crc_type()
+    ETL_CONSTEXPR14 crc_type()
     {
       this->reset();
     }
@@ -702,7 +729,7 @@ namespace etl
     /// \param end   End of the range.
     //*************************************************************************
     template<typename TIterator>
-    crc_type(TIterator begin, const TIterator end)
+    ETL_CONSTEXPR14 crc_type(TIterator begin, const TIterator end)
     {
       this->reset();
       this->add(begin, end);

diff --git a/test/test_crc16.cpp b/test/test_crc16.cpp
@@ -127,6 +127,17 @@ namespace
       CHECK_EQUAL(0xBB3DU, crc);
     }
 
+#if ETL_USING_CPP14
+    //*************************************************************************
+    TEST(test_crc16_16_constexpr)
+    {
+      constexpr char data[] = "123456789";
+      constexpr uint16_t crc = etl::crc16_t16(data, data + 9);
+
+      CHECK_EQUAL(0xBB3DU, crc);
+    }
+#endif
+
     //*************************************************************************
     TEST(test_crc16_16_add_values)
     {
@@ -199,6 +210,17 @@ namespace
       CHECK_EQUAL(0xBB3DU, crc);
     }
 
+#if ETL_USING_CPP14
+    //*************************************************************************
+    TEST(test_crc16_4_constexpr)
+    {
+      constexpr char data[] = "123456789";
+      constexpr uint16_t crc = etl::crc16_t4(data, data + 9);
+
+      CHECK_EQUAL(0xBB3DU, crc);
+    }
+#endif
+
     //*************************************************************************
     TEST(test_crc16_4_add_values)
     {

diff --git a/test/test_crc16_a.cpp b/test/test_crc16_a.cpp
@@ -55,6 +55,17 @@ namespace
       CHECK_EQUAL(0xBF05U, crc);
     }
 
+#if ETL_USING_CPP14
+    //*************************************************************************
+    TEST(test_crc16_a_constexpr)
+    {
+      constexpr char data[] = "123456789";
+      constexpr uint16_t crc = etl::crc16_a(data, data + 9);
+
+      CHECK_EQUAL(0xBF05U, crc);
+    }
+#endif
+
     //*************************************************************************
     TEST(test_crc16_a_add_values)
     {
@@ -127,6 +138,17 @@ namespace
       CHECK_EQUAL(0xBF05U, crc);
     }
 
+#if ETL_USING_CPP14
+    //*************************************************************************
+    TEST(test_crc16_a_16_constexpr)
+    {
+      constexpr char data[] = "123456789";
+      constexpr uint16_t crc = etl::crc16_a_t16(data, data + 9);
+
+      CHECK_EQUAL(0xBF05U, crc);
+    }
+#endif
+
     //*************************************************************************
     TEST(test_crc16_a_16_add_values)
     {
@@ -199,6 +221,17 @@ namespace
       CHECK_EQUAL(0xBF05U, crc);
     }
 
+#if ETL_USING_CPP14
+    //*************************************************************************
+    TEST(test_crc16_a_4_constexpr)
+    {
+      constexpr char data[] = "123456789";
+      constexpr uint16_t crc = etl::crc16_a_t4(data, data + 9);
+
+      CHECK_EQUAL(0xBF05U, crc);
+    }
+#endif
+
     //*************************************************************************
     TEST(test_crc16_a_4_add_values)
     {

diff --git a/test/test_crc16_arc.cpp b/test/test_crc16_arc.cpp
@@ -55,6 +55,17 @@ namespace
       CHECK_EQUAL(0xBB3DU, crc);
     }
 
+#if ETL_USING_CPP14
+    //*************************************************************************
+    TEST(test_crc16_arc_constexpr)
+    {
+      constexpr char data[] = "123456789";
+      constexpr uint16_t crc = etl::crc16_arc(data, data + 9);
+
+      CHECK_EQUAL(0xBB3DU, crc);
+    }
+#endif
+
     //*************************************************************************
     TEST(test_crc16_arc_add_values)
     {
@@ -127,6 +138,17 @@ namespace
       CHECK_EQUAL(0xBB3DU, crc);
     }
 
+#if ETL_USING_CPP14
+    //*************************************************************************
+    TEST(test_crc16_arc_16_constexpr)
+    {
+      constexpr char data[] = "123456789";
+      constexpr uint16_t crc = etl::crc16_arc_t16(data, data + 9);
+
+      CHECK_EQUAL(0xBB3DU, crc);
+    }
+#endif
+
     //*************************************************************************
     TEST(test_crc16_arc_16_add_values)
     {
@@ -199,6 +221,17 @@ namespace
       CHECK_EQUAL(0xBB3DU, crc);
     }
 
+#if ETL_USING_CPP14
+    //*************************************************************************
+    TEST(test_crc16_arc_4_constexpr)
+    {
+      constexpr char data[] = "123456789";
+      constexpr uint16_t crc = etl::crc16_arc_t4(data, data + 9);
+
+      CHECK_EQUAL(0xBB3DU, crc);
+    }
+#endif
+
     //*************************************************************************
     TEST(test_crc16_arc_4_add_values)
     {