Merge #13580: build: Detect if char equals int8_t

49d1f4c Detect if char equals int8_t (Chun Kuan Lee)

Pull request description:

  Probably fixes #13576. I'm not able to test this. @stacepellegrino, can you test this?

Tree-SHA512: b750e00e11e6b6f6341fec668ec2254cc101c8ebdd4878f320d6cb3b07cf326761146e4ceff0b6405b7e503ff64c093a8274bd524a097e2c49382dc296972c4f

Author: laanwj

configure.ac

@@ -808,6 +808,14 @@ 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)]
+)
+
 # Check for reduced exports
 if test x$use_reduce_exports = xyes; then
   AX_CHECK_COMPILE_FLAG([-fvisibility=hidden],[RE_CXXFLAGS="-fvisibility=hidden"],

src/serialize.h

@@ -189,7 +189,9 @@ template<typename X> const X& ReadWriteAsHelper(const X& x) { return x; }
         SerializationOp(s, CSerActionUnserialize());                  \
     }
 
+#ifndef CHAR_EQUALS_INT8
 template<typename Stream> inline void Serialize(Stream& s, char a    ) { ser_writedata8(s, a); } // TODO Get rid of bare char
+#endif
 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); }
 template<typename Stream> inline void Serialize(Stream& s, int16_t a ) { ser_writedata16(s, a); }
@@ -205,7 +207,9 @@ template<typename Stream, int N> inline void Serialize(Stream& s, const unsigned
 template<typename Stream> inline void Serialize(Stream& s, const Span<const unsigned char>& span) { s.write(CharCast(span.data()), span.size()); }
 template<typename Stream> inline void Serialize(Stream& s, const Span<unsigned char>& span) { s.write(CharCast(span.data()), span.size()); }
 
+#ifndef CHAR_EQUALS_INT8
 template<typename Stream> inline void Unserialize(Stream& s, char& a    ) { a = ser_readdata8(s); } // TODO Get rid of bare char
+#endif
 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); }
 template<typename Stream> inline void Unserialize(Stream& s, int16_t& a ) { a = ser_readdata16(s); }