compiling C Funktion for PostgreSQL

Hello,

I have a problem with the postgreSQL Source Code when I compile the fuzzystrmatch.c. I want to try to replace all german umlauts for the soundex algorithm. But when I want to compile the C Code, I get an error on the following line in the fuzzystrmatch.c:

PG_MODULE_MAGIC;

And here is the error I get:

In function 'Pg_magic_func': 'PG_VERSION_NUM' undeclared (first use in function)

The PG_VERSION_NUM is defined in the fmgr.h of the PostgreSQL Source Code:

/* Definition of the magic block structure */
typedef struct
{
    int            len;            /* sizeof(this struct) */
    int            version;        /* PostgreSQL major version */
    int            funcmaxargs;    /* FUNC_MAX_ARGS */
    int            indexmaxkeys;    /* INDEX_MAX_KEYS */
    int            namedatalen;    /* NAMEDATALEN */
} Pg_magic_struct;


/* The actual data block contents */
#define PG_MODULE_MAGIC_DATA \
{ 
    sizeof(Pg_magic_struct), 
    PG_VERSION_NUM / 100, 
    FUNC_MAX_ARGS, 
    INDEX_MAX_KEYS, 
    NAMEDATALEN 
}

Can anyone help me to figure out this problem?

Thanks in advance

Jürgen Ulrich