use Boost.Endian for endianness

Author: grisumbras

CMakeLists.txt

@@ -78,6 +78,7 @@ function(boost_json_setup_properties target)
             Boost::container_hash
             Boost::core
             Boost::describe
+            Boost::endian
             Boost::mp11
             Boost::system
             Boost::throw_exception

include/boost/json/detail/charconv/detail/fast_float/ascii_number.hpp

@@ -8,6 +8,7 @@
 #ifndef BOOST_JSON_DETAIL_CHARCONV_DETAIL_FASTFLOAT_ASCII_NUMBER_HPP
 #define BOOST_JSON_DETAIL_CHARCONV_DETAIL_FASTFLOAT_ASCII_NUMBER_HPP
 
+#include <boost/endian/conversion.hpp>
 #include <boost/json/detail/charconv/detail/fast_float/float_common.hpp>
 #include <cctype>
 #include <cstdint>
@@ -46,10 +47,7 @@ uint64_t read_u64(const char *chars) {
   }
   uint64_t val;
   ::memcpy(&val, chars, sizeof(uint64_t));
-#ifdef BOOST_JSON_BIG_ENDIAN
-  // Need to read as-if the number was in little-endian order.
-  val = byteswap(val);
-#endif
+  endian::little_to_native_inplace(val);
   return val;
 }
 
@@ -63,10 +61,7 @@ void write_u64(uint8_t *chars, uint64_t val) {
     }
     return;
   }
-#ifdef BOOST_JSON_BIG_ENDIAN
-  // Need to read as-if the number was in little-endian order.
-  val = byteswap(val);
-#endif
+  endian::native_to_little_inplace(val);
   ::memcpy(chars, &val, sizeof(uint64_t));
 }
 

include/boost/json/detail/config.hpp

@@ -234,24 +234,6 @@
 # endif
 #endif
 
-
-#if ! defined(BOOST_JSON_BIG_ENDIAN) && ! defined(BOOST_JSON_LITTLE_ENDIAN)
-// Copied from Boost.Endian
-# if defined(__BYTE_ORDER__) && defined(__ORDER_LITTLE_ENDIAN__) && __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
-#  define BOOST_JSON_LITTLE_ENDIAN
-# elif defined(__BYTE_ORDER__) && defined(__ORDER_BIG_ENDIAN__) && __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
-#  define BOOST_JSON_BIG_ENDIAN
-# elif defined(__LITTLE_ENDIAN__)
-#  define BOOST_JSON_LITTLE_ENDIAN
-# elif defined(__BIG_ENDIAN__)
-#  define BOOST_JSON_BIG_ENDIAN
-# elif defined(_MSC_VER) || defined(__i386__) || defined(__x86_64__)
-#  define BOOST_JSON_LITTLE_ENDIAN
-# else
-#  error The Boost.JSON library could not determine the endianness of this platform. Define either BOOST_JSON_BIG_ENDIAN or BOOST_JSON_LITTLE_ENDIAN.
-# endif
-#endif
-
 #if defined(__cpp_constinit) && __cpp_constinit >= 201907L
 # define BOOST_JSON_CONSTINIT constinit
 #elif defined(__has_cpp_attribute) && defined(__clang__)

include/boost/json/detail/sse2.hpp

@@ -327,6 +327,7 @@ inline uint64_t parse_unsigned( uint64_t r, char const * p, std::size_t n ) noex
 #else
         uint32_t v;
         std::memcpy( &v, p, 4 );
+        endian::native_to_little_inplace(v);
 
         v -= 0x30303030;
 
@@ -335,11 +336,7 @@ inline uint64_t parse_unsigned( uint64_t r, char const * p, std::size_t n ) noex
         unsigned w2 = (v >> 16) & 0xFF;
         unsigned w3 = (v >> 24);
 
-#ifdef BOOST_JSON_BIG_ENDIAN
-        r = (((r * 10 + w3) * 10 + w2) * 10 + w1) * 10 + w0;
-#else
         r = (((r * 10 + w0) * 10 + w1) * 10 + w2) * 10 + w3;
-#endif
 #endif
         p += 4;
         n -= 4;

include/boost/json/detail/utf8.hpp

@@ -10,6 +10,7 @@
 #ifndef BOOST_JSON_DETAIL_UTF8_HPP
 #define BOOST_JSON_DETAIL_UTF8_HPP
 
+#include <boost/endian/conversion.hpp>
 #include <boost/json/detail/config.hpp>
 
 #include <cstddef>
@@ -26,12 +27,7 @@ load_little_endian(void const* p)
 {
     std::uint32_t v = 0;
     std::memcpy(&v, p, N);
-#ifdef BOOST_JSON_BIG_ENDIAN
-    v = ((v & 0xFF000000) >> 24) |
-        ((v & 0x00FF0000) >>  8) |
-        ((v & 0x0000FF00) <<  8) |
-        ((v & 0x000000FF) << 24);
-#endif
+    endian::little_to_native_inplace(v);
     return v;
 }
 

test/cmake-subdir/CMakeLists.txt

@@ -18,6 +18,7 @@ add_subdirectory(../../../container       boostorg/container)
 add_subdirectory(../../../container_hash  boostorg/container_hash)
 add_subdirectory(../../../core            boostorg/core)
 add_subdirectory(../../../describe        boostorg/describe)
+add_subdirectory(../../../endian          boostorg/endian)
 add_subdirectory(../../../intrusive       boostorg/intrusive)
 add_subdirectory(../../../json            boostorg/json)
 add_subdirectory(../../../move            boostorg/move)