serialization: replace char-is-int8_t autoconf detection with c++20 concept

This removes the only remaining autoconf macro in our serialization code,
so it can now be used trivially and safely out-of-tree.
This commit is contained in:
Cory Fields 2024-02-26 19:52:14 +00:00
parent 4d7d7fd123
commit ad7584d8b6
2 changed files with 10 additions and 18 deletions

View file

@ -1174,14 +1174,6 @@ AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[#include <sys/types.h>
[ AC_MSG_RESULT([no])]
)
AC_MSG_CHECKING([for if type char equals int8_t])
AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[#include <stdint.h>
#include <type_traits>]],
[[ static_assert(std::is_same<int8_t, char>::value, ""); ]])],
[ AC_MSG_RESULT([yes]); AC_DEFINE([CHAR_EQUALS_INT8], [1], [Define this symbol if type char equals int8_t]) ],
[ AC_MSG_RESULT([no])]
)
AC_MSG_CHECKING([for fdatasync])
AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[#include <unistd.h>]],
[[ fdatasync(0); ]])],

View file

@ -6,10 +6,6 @@
#ifndef BITCOIN_SERIALIZE_H
#define BITCOIN_SERIALIZE_H
#if defined(HAVE_CONFIG_H)
#include <config/bitcoin-config.h>
#endif
#include <attributes.h>
#include <compat/assumptions.h> // IWYU pragma: keep
#include <compat/endian.h>
@ -17,6 +13,7 @@
#include <span.h>
#include <algorithm>
#include <concepts>
#include <cstdint>
#include <cstring>
#include <ios>
@ -263,9 +260,14 @@ const Out& AsBase(const In& x)
// i.e. anything that supports .read(Span<std::byte>) and .write(Span<const std::byte>)
//
// clang-format off
#ifndef CHAR_EQUALS_INT8
template <typename Stream> void Serialize(Stream&, char) = delete; // char serialization forbidden. Use uint8_t or int8_t
#endif
// Typically int8_t and char are distinct types, but some systems may define int8_t
// in terms of char. Forbid serialization of char in the typical case, but allow it if
// it's the only way to describe an int8_t.
template<class T>
concept CharNotInt8 = std::same_as<T, char> && !std::same_as<T, int8_t>;
template <typename Stream, CharNotInt8 V> void Serialize(Stream&, V) = delete; // char serialization forbidden. Use uint8_t or int8_t
template <typename Stream> void Serialize(Stream& s, std::byte a) { ser_writedata8(s, uint8_t(a)); }
template<typename Stream> inline void Serialize(Stream& s, int8_t a ) { ser_writedata8(s, a); }
template<typename Stream> inline void Serialize(Stream& s, uint8_t a ) { ser_writedata8(s, a); }
@ -279,9 +281,7 @@ template <typename Stream, BasicByte B, int N> void Serialize(Stream& s, const B
template <typename Stream, BasicByte B, std::size_t N> void Serialize(Stream& s, const std::array<B, N>& a) { s.write(MakeByteSpan(a)); }
template <typename Stream, BasicByte B> void Serialize(Stream& s, Span<B> span) { s.write(AsBytes(span)); }
#ifndef CHAR_EQUALS_INT8
template <typename Stream> void Unserialize(Stream&, char) = delete; // char serialization forbidden. Use uint8_t or int8_t
#endif
template <typename Stream, CharNotInt8 V> void Unserialize(Stream&, V) = delete; // char serialization forbidden. Use uint8_t or int8_t
template <typename Stream> void Unserialize(Stream& s, std::byte& a) { a = std::byte{ser_readdata8(s)}; }
template<typename Stream> inline void Unserialize(Stream& s, int8_t& a ) { a = ser_readdata8(s); }
template<typename Stream> inline void Unserialize(Stream& s, uint8_t& a ) { a = ser_readdata8(s); }