[cfe-users] Porting preprocessor macros to be compatible with clang

[Forumer 4umer via cfe-users]

So a bit more explanation, the macros are used to generate data 
structure and methods and the following definition is used to declare a 
structure:

DEF_STRUCT(namedDate, namedDate, (std::string, name), (std::time_t, 
date))

On visual when I look at preprocessed file I get this (focus on line 
starting with struct namedDate) :

namespace LibTech
{
    namespace DataTypes
    {
       #line 1 "E:\\DEV\\FixMacroOnClang\\DeclareDatatypes.h"
       #line 17 "E:\\DEV\\FixMacroOnClang\\DeclareDatatypes.h"
       #line 12 "E:\\DEV\\FixMacroOnClang\\Protocol.h"
       #line 1 "E:\\DEV\\FixMacroOnClang\\DataTypesDef.h"

struct namedDate{ std::string name; std::time_t date; };

       #line 13 "E:\\DEV\\FixMacroOnClang\\Protocol.h"
       #line 1 "E:\\DEV\\FixMacroOnClang\\DeclareDatatypes.h"
	  #line 1 "E:\\DEV\\FixMacroOnClang\\macro\\UndefDataTypesDef.h"
	  #line 14 "E:\\DEV\\FixMacroOnClang\\DeclareDatatypes.h"
	  #line 17 "E:\\DEV\\FixMacroOnClang\\DeclareDatatypes.h"
	  #line 14 "E:\\DEV\\FixMacroOnClang\\Protocol.h"
    }

}

but when using clang I have this:

namespace LibTech
{
    namespace DataTypes
    {
       # 1 "E:\\DEV\\FixMacroOnClang/DeclareDatatypes.h" 1
       # 12 "E:\\DEV\\FixMacroOnClang/Protocol.h" 2
       # 1 "E:\\DEV\\FixMacroOnClang/DataTypesDef.h" 1

struct namedDate{ PP_GS 2 (TO_FIELD, (std::string, name), (std::time_t, 
date)) };

       # 13 "E:\\DEV\\FixMacroOnClang/Protocol.h" 2
       # 1 "E:\\DEV\\FixMacroOnClang/DeclareDatatypes.h" 1
       # 13 "E:\\DEV\\FixMacroOnClang/DeclareDatatypes.h"
       # 1 "E:\\DEV\\FixMacroOnClang/./macro/UndefDataTypesDef.h" 1
       # 14 "E:\\DEV\\FixMacroOnClang/DeclareDatatypes.h" 2
       # 14 "E:\\DEV\\FixMacroOnClang/Protocol.h" 2
  }
}

as you can see the macros used inside preprocessor.h doesn't work with 
clang I have macro PP_GS and TO_FIELD macros that are not expanded.

I cannot copy/paste all macro definitions because it won't be very easy 
to read but here is how it starts:

#ifndef DEF_ID_BEGIN

//...

#define TO_FIELD(type, name) type name;
#define DEF_STRUCT(type, dataTypeId, ...) struct type{ 
PP_FOREACH_GROUP(TO_FIELD,__VA_ARGS__) };

#else

#include "./macro/UndefDataTypesDef.h"
#undef TO_FIELD

#endif

and inside preprocessor.h

#define PP_PREFIX(Method) PP_##Method
#define PP_SUFFIX(N) N
#define PP_ENTRY(Method,N) PP_PREFIX(Method)PP_SUFFIX(N)
#define PP_CALL_PP_SN( Method, Func, N, ...) PP_ENTRY(Method,N) 
PP_FW(Func, __VA_ARGS__)

#define PP_FOREACH(Func, ...) PP_CALL_PP_SN( S, Func, PP_ARGCOUNT 
PP_FW(__VA_ARGS__), __VA_ARGS__ )
#define PP_FOREACH_GROUP(Func, ...) PP_CALL_PP_SN( GS, Func, PP_ARGCOUNT 
PP_FW(__VA_ARGS__), __VA_ARGS__ )


#define PP_RSEQ_N()\
63 ,62 ,61 ,60 ,\
59 ,58 ,57 ,56 ,55 ,54 ,53 ,52 ,51 ,50 ,\
49 ,48 ,47 ,46 ,45 ,44 ,43 ,42 ,41 ,40 ,\
39 ,38 ,37 ,36 ,35 ,34 ,33 ,32 ,31 ,30 ,\
29 ,28 ,27 ,26 ,25 ,24 ,23 ,22 ,21 ,20 ,\
19 ,18 ,17 ,16 ,15 ,14 ,13 ,12 ,11 ,10 ,\
9,8,7,6,5,4,3,2,1,0

#define PP_ARG_N( \
_1  ,_2  ,_3  ,_4  ,_5  ,_6  ,_7  ,_8  ,_9  ,_10 ,\
_11 ,_12 ,_13 ,_14 ,_15 ,_16 ,_17 ,_18 ,_19 ,_20 ,\
_21 ,_22 ,_23 ,_24 ,_25 ,_26 ,_27 ,_28 ,_29 ,_30 ,\
_31 ,_32 ,_33 ,_34 ,_35 ,_36 ,_37 ,_38 ,_39 ,_40 ,\
_41 ,_42 ,_43 ,_44 ,_45 ,_46 ,_47 ,_48 ,_49 ,_50 ,\
_51 ,_52 ,_53 ,_54 ,_55 ,_56 ,_57 ,_58 ,_59 ,_60 ,\
_61 ,_62 ,_63 ,  N , ...) N

#define PP_FW(...) (__VA_ARGS__)
#define PP_NARG_(...) PP_ARG_N PP_FW(__VA_ARGS__)
#define PP_ARGCOUNT(...) PP_NARG_(__VA_ARGS__,PP_RSEQ_N())

but have a look here to see all the macros: 
https://github.com/vrichomme/FixMacroOnClang/blob/master/preprocessor.h

Maybe one of the problem is with PP_FW(...) but not sure about that...

Thanks