IDA Help: Xrefs

//      See sample file xrefs.idc to learn to use these functions.

//      Flow types (combine with XREF_USER!):
#define fl_CF   16              // Call Far
#define fl_CN   17              // Call Near
#define fl_JF   18              // jumpto Far
#define fl_JN   19              // jumpto Near
#define fl_F    21              // Ordinary flow

#define XREF_USER 32            // All user-specified xref types
                                // must be combined with this bit

// Mark exec flow 'from' 'to'
success add_cref(long from, long to, long flowtype);

// Unmark exec flow 'from' 'to'
// undef - make 'to' undefined if no
//        more references to it
// returns 1 - planned to be made undefined
long del_cref(long from, long to, int undef);

// The following functions include the ordinary flows:
// (the ordinary flow references are returned first)

// Get first code xref from 'from'
long get_first_cref_from(long From);

// Get next code xref from
long get_next_cref_from(long from, long current);

// Get first code xref to 'to'
long get_first_cref_to(long to);

// Get next code xref to 'to'
long get_next_cref_to(long to, long current);

// The following functions don't take into account the ordinary flows:
long get_first_fcref_from(long from);
long get_next_fcref_from(long from, long current);
long get_first_fcref_to(long to);
long get_next_fcref_to(long to, long current);

// Data reference types (combine with XREF_USER!):
#define dr_O    1                       // Offset
#define dr_W    2                       // Write
#define dr_R    3                       // Read
#define dr_T    4                       // Text (names in manual operands)
#define dr_I    5                       // Informational

// Create Data Ref
success add_dref(long From, long to, long dreftype);

// Unmark Data Ref
void del_dref(long from, long to);

// Get first data xref from 'from'
long get_first_dref_from(long from);
long get_next_dref_from(long From, long current);

// Get first data xref to 'to'
long get_first_dref_to(long to);
long get_next_dref_to(long to, long current);

// returns type of the last xref
// obtained by get_first_.../get_next_...
// functions. Return values
// are fl_... or dr_...
long get_xref_type();