xmacro-codegen

01README.md

X-Macros Code Generator in C11

Because we can and the C-preprocessor is wasting CPU cycles anyway

main.c

#include <stdio.h>
#include "obj.h"

int main(void)
{
	struct coordinate a;
	struct blaat b;
	struct big c;

	a.x = 1;
	a.y = 2;
	a.z = 3;

	b.coord = &a;

	OBJ_SERIALIZE(&a);
	OBJ_SERIALIZE(&b);
	OBJ_SERIALIZE(&c);

	return 0;
}

Makefile

CFLAGS:=-Wall -Wextra -std=c11

main: main.c obj.def obj.h
	clang $(CFLAGS) -o main main.c
main.c.pp: main.c obj.def obj.h
	clang $(CFLAGS) -E -P main.c > main.c.pp
test: main
	./main
clean:
	rm -f main main.c.pp

obj.def

#ifndef OBJ_SERIALIZE
#define OBJ_SERIALIZE(x) \
	_Generic((x),                                      \
		       struct big *: big_serialize,        \
		struct coordinate *: coordinate_serialize, \
		     struct blaat *: blaat_serialize,      \
		            uint8_t: obj_serialize_u8,     \
		           uint16_t: obj_serialize_u16,    \
		           uint32_t: obj_serialize_u32     \
	)(x)
#endif

OBJ_DECL(big)
	OBJ_MEMBER(uint8_t,  a)
	OBJ_MEMBER(uint16_t, b)
	OBJ_MEMBER(uint32_t, c)
OBJ_DECL_END()

OBJ_DECL(coordinate)
	OBJ_MEMBER(uint32_t, x)
	OBJ_MEMBER(uint32_t, y)
	OBJ_MEMBER(uint32_t, z)
OBJ_DECL_END()

OBJ_DECL(blaat)
	OBJ_MEMBER(uint16_t, uid)
	OBJ_MEMBER(struct coordinate *, coord)
OBJ_DECL_END()

obj.h

#include <stdint.h>

#ifndef OBJ_H_
#define OBJ_H_

#define OBJ_XSTR(s) OBJ_STR(s)
#define OBJ_STR(s) #s

/* Start with macro declaration */
#ifndef OBJ_PP_DECLARE
#define OBJ_PP_DECLARE
#endif

/* Generate structs */
#define OBJ_DECL(name) \
	struct name {
#define OBJ_MEMBER(type, name) type name;
#define OBJ_DECL_END() \
	};
#include "obj.h"
#include "obj.def"
#include "obj.h"

void obj_serialize_u8(uint8_t v){ (void)v; printf("\t-> %s (%u)\n", __func__, v);}
void obj_serialize_u16(uint16_t v){ (void)v; printf("\t-> %s (%u)\n", __func__, v);}
void obj_serialize_u32(uint32_t v){ (void)v; printf("\t-> %s (%u)\n", __func__, v);}

/* Generate functions */
#define OBJ_DECL(name) \
	void name##_serialize(struct name *val) \
	{ \
		(void)val; \
		if (!val)\
			return;\
\
		printf("func: %s (struct %s)\n", __func__, OBJ_STR(name));
#define OBJ_MEMBER(type, name) \
		printf("\tmember %s %s", OBJ_STR(type), OBJ_STR(name)); \
		OBJ_SERIALIZE(val->name);
#define OBJ_DECL_END() \
	}
#include "obj.h"
#include "obj.def"
#include "obj.h"

#endif

#ifdef OBJ_PP_DECLARE
#	ifndef OBJ_DECL
#		define OBJ_DECL(name)
#	endif
#	ifndef OBJ_MEMBER
#		define OBJ_MEMBER(type, name)
#	endif
#	ifndef OBJ_DECL_END
#		define OBJ_DECL_END()
#	endif
#undef	OBJ_PP_DECLARE
#else
#	ifdef OBJ_DECL
#		undef OBJ_DECL
#	endif
#	ifdef OBJ_MEMBER
#		undef OBJ_MEMBER
#	endif
#	ifdef OBJ_DECL_END
#		undef OBJ_DECL_END
#	endif
#define OBJ_PP_DECLARE
#endif