GNU Make C API - hello world

expand_make.c

#include <stdio.h>
#include <string.h>
#include <gnumake.h>
int plugin_is_GPL_compatible;
#define FUNC_STATIC GMK_FUNC_DEFAULT
#define FUNC_REFLEXIVE GMK_FUNC_NOEXPAND

char *hello()
{
    return (strdup("hello, world\n"));
}

char *say(char const *av0, unsigned int ac, char **av)
{
    return (strdup(*av));
}

int moul_gmk_setup()
{
    gmk_add_function ("hello", &hello, 0, 0, FUNC_STATIC);
    gmk_add_function ("say", &say, 1, 1, FUNC_STATIC);
    return (1);
}

void say_hello()
{
    printf("hello, world\n");
}

Makefile

CC :=		gcc
CFLAGS :=	-fpic
LD :=		$(CC)
LDFLAGS :=	-shared
LDLIBS :=

all:;		@echo $(hello )

say:;		@echo $(say "hello, world")

hello:;		@$(MAKE) --no-print-directory do_hello
ifeq ($(MAKECMDGOALS),do_hello)
-load moul.so(say_hello)
do_hello:;@:
else
-load moul.so
endif

moul.so:	expand_make.c
		$(CC) $(CFLAGS) -o $@ $^ $(LDFLAGS) $(LDLIBS)

.PHONY:		all say hello