xref.hpp File Reference

Functions that deal with cross-references. More...

Classes
struct	xrefblk_t
	Structure to enumerate all xrefs. More...

Macros
#define	XREF_USER   0x20
	User specified xref. More...
#define	XREF_TAIL   0x40
	Reference to tail byte in extrn symbols.
#define	XREF_BASE   0x80
	Reference to the base part of an offset.
#define	XREF_MASK   0x1F
	Mask to get xref type.
#define	XREF_PASTEND   0x100
	Reference is past item. More...
#define	XREF_ALL   0x00
	return all references
#define	XREF_FAR   0x01
	don't return ordinary flow xrefs
#define	XREF_DATA   0x02
	return data references only

Enumerations
enum	cref_t {   fl_U , fl_CF = 16 , fl_CN , fl_JF ,   fl_JN , fl_USobsolete , fl_F }
	CODE xref types. More...
enum	dref_t {   dr_U , dr_O , dr_W , dr_R ,   dr_T , dr_I , dr_S }
	DATA xref types. More...

Functions
idaman char ida_export	xrefchar (char xrtype)
	Get character describing the xref type. More...
idaman bool ida_export	add_cref (ea_t from, ea_t to, cref_t type)
	Create a code cross-reference. More...
idaman bool ida_export	del_cref (ea_t from, ea_t to, bool expand)
	Delete a code cross-reference. More...
idaman bool ida_export	add_dref (ea_t from, ea_t to, dref_t type)
	Create a data cross-reference. More...
idaman void ida_export	del_dref (ea_t from, ea_t to)
	Delete a data cross-reference. More...
Helper functions
Should not be called directly!
idaman bool ida_export	xrefblk_t_first_from (xrefblk_t *, ea_t from, int flags)
idaman bool ida_export	xrefblk_t_next_from (xrefblk_t *)
idaman bool ida_export	xrefblk_t_first_to (xrefblk_t *, ea_t to, int flags)
idaman bool ida_export	xrefblk_t_next_to (xrefblk_t *)
idaman ea_t ida_export	get_first_dref_from (ea_t from)
	Get first data referenced from the specified address. More...
idaman ea_t ida_export	get_next_dref_from (ea_t from, ea_t current)
	Get next data referenced from the specified address. More...
idaman ea_t ida_export	get_first_dref_to (ea_t to)
	Get address of instruction/data referencing to the specified data. More...
idaman ea_t ida_export	get_next_dref_to (ea_t to, ea_t current)
	Get address of instruction/data referencing to the specified data. More...
idaman ea_t ida_export	get_first_cref_from (ea_t from)
	Get first instruction referenced from the specified instruction. More...
idaman ea_t ida_export	get_next_cref_from (ea_t from, ea_t current)
	Get next instruction referenced from the specified instruction. More...
idaman ea_t ida_export	get_first_cref_to (ea_t to)
	Get first instruction referencing to the specified instruction. More...
idaman ea_t ida_export	get_next_cref_to (ea_t to, ea_t current)
	Get next instruction referencing to the specified instruction. More...
Far code references
The following functions are similar to get_{first|next}_cref_{from|to} functions. The only difference is that they don't take into account ordinary flow of execution. Only jump and call xrefs are returned. (fcref means "far code reference")
idaman ea_t ida_export	get_first_fcref_from (ea_t from)
idaman ea_t ida_export	get_next_fcref_from (ea_t from, ea_t current)
idaman ea_t ida_export	get_first_fcref_to (ea_t to)
idaman ea_t ida_export	get_next_fcref_to (ea_t to, ea_t current)
idaman bool ida_export	has_external_refs (func_t *pfn, ea_t ea)
	Does 'ea' have references from outside of 'pfn'?

Detailed Description

Functions that deal with cross-references.

There are 2 types of xrefs: CODE and DATA references. All xrefs are kept in the bTree except ordinary execution flow to the next instruction. Ordinary execution flow to the next instruction is kept in flags (see bytes.hpp)

The source address of a cross-reference must be an item head (is_head) or a structure member id.

Cross-references are automatically sorted.

Macro Definition Documentation

XREF_USER

#define XREF_USER   0x20

User specified xref.

This xref will not be deleted by IDA. This bit should be combined with the existing xref types (cref_t & dref_t) Cannot be used for fl_F xrefs

XREF_PASTEND

#define XREF_PASTEND   0x100

Reference is past item.

This bit may be passed to add_dref() functions but it won't be saved in the database. It will prevent the destruction of eventual alignment directives.

Enumeration Type Documentation

cref_t

enum cref_t

CODE xref types.

Enumerator
fl_U	unknown – for compatibility with old versions. Should not be used anymore.
fl_CF	Call Far This xref creates a function at the referenced location.
fl_CN	Call Near This xref creates a function at the referenced location.
fl_JF	Jump Far.
fl_JN	Jump Near.
fl_USobsolete	User specified (obsolete)
fl_F	Ordinary flow: used to specify execution flow to the next instruction.

dref_t

enum dref_t

DATA xref types.

Enumerator
dr_U	Unknown – for compatibility with old versions. Should not be used anymore.
dr_O	Offset The reference uses 'offset' of data rather than its value OR The reference appeared because the "OFFSET" flag of instruction is set. The meaning of this type is IDP dependent.
dr_W	Write access.
dr_R	Read access.
dr_T	Text (for forced operands only) Name of data is used in manual operand.
dr_I	Informational (a derived java class references its base class informationally)
dr_S	Reference to enum member (symbolic constant)

Function Documentation

xrefchar()

idaman char ida_export xrefchar

(

char

xrtype

)

Get character describing the xref type.

Parameters

xrtype

combination of Cross-Reference type flags and a cref_t of dref_t value

add_cref()

idaman bool ida_export add_cref	(	ea_t	from,
		ea_t	to,
		cref_t	type
	)

Create a code cross-reference.

Parameters

from	linear address of referencing instruction
to	linear address of referenced instruction
type	cross-reference type

Returns

success

del_cref()

idaman bool ida_export del_cref	(	ea_t	from,
		ea_t	to,
		bool	expand
	)

Delete a code cross-reference.

Parameters

from	linear address of referencing instruction
to	linear address of referenced instruction
expand	policy to delete the referenced instruction 1: plan to delete the referenced instruction if it has no more references. 0: don't delete the referenced instruction even if no more cross-references point to it

Return values

true	if the referenced instruction will be deleted

add_dref()

idaman bool ida_export add_dref	(	ea_t	from,
		ea_t	to,
		dref_t	type
	)

Create a data cross-reference.

Parameters

from	linear address of referencing instruction or data
to	linear address of referenced data
type	cross-reference type

Returns

success (may fail if user-defined xref exists from->to)

del_dref()

idaman void ida_export del_dref	(	ea_t	from,
		ea_t	to
	)

Delete a data cross-reference.

Parameters

from	linear address of referencing instruction or data
to	linear address of referenced data

get_first_dref_from()

idaman ea_t ida_export get_first_dref_from

(

ea_t

from

)

Get first data referenced from the specified address.

Parameters

from	linear address of referencing instruction or data

Returns

linear address of first (lowest) data referenced from the specified address. Return BADADDR if the specified instruction/data doesn't reference to anything.

get_next_dref_from()

idaman ea_t ida_export get_next_dref_from	(	ea_t	from,
		ea_t	current
	)

Get next data referenced from the specified address.

Parameters

from	linear address of referencing instruction or data
current	linear address of current referenced data. This value is returned by get_first_dref_from() or previous call to get_next_dref_from() functions.

Returns

linear address of next data or BADADDR.

get_first_dref_to()

idaman ea_t ida_export get_first_dref_to

(

ea_t

to

)

Get address of instruction/data referencing to the specified data.

Parameters

to	linear address of referencing instruction or data

Returns

BADADDR if nobody refers to the specified data.

get_next_dref_to()

idaman ea_t ida_export get_next_dref_to	(	ea_t	to,
		ea_t	current
	)

Get address of instruction/data referencing to the specified data.

Parameters

to	linear address of referencing instruction or data
current	current linear address. This value is returned by get_first_dref_to() or previous call to get_next_dref_to() functions.

Returns

BADADDR if nobody refers to the specified data.

get_first_cref_from()

idaman ea_t ida_export get_first_cref_from

(

ea_t

from

)

Get first instruction referenced from the specified instruction.

If the specified instruction passes execution to the next instruction then the next instruction is returned. Otherwise the lowest referenced address is returned (remember that xrefs are kept sorted!).

Parameters

from	linear address of referencing instruction

Returns

first referenced address. If the specified instruction doesn't reference to other instructions then returns BADADDR.

get_next_cref_from()

idaman ea_t ida_export get_next_cref_from	(	ea_t	from,
		ea_t	current
	)

Get next instruction referenced from the specified instruction.

Parameters

from	linear address of referencing instruction
current	linear address of current referenced instruction This value is returned by get_first_cref_from() or previous call to get_next_cref_from() functions.

Returns

next referenced address or BADADDR.

get_first_cref_to()

idaman ea_t ida_export get_first_cref_to

(

ea_t

to

)

Get first instruction referencing to the specified instruction.

If the specified instruction may be executed immediately after its previous instruction then the previous instruction is returned. Otherwise the lowest referencing address is returned. (remember that xrefs are kept sorted!).

Parameters

to	linear address of referenced instruction

Returns

linear address of the first referencing instruction or BADADDR.

get_next_cref_to()

idaman ea_t ida_export get_next_cref_to	(	ea_t	to,
		ea_t	current
	)

Get next instruction referencing to the specified instruction.

Parameters

to	linear address of referenced instruction
current	linear address of current referenced instruction This value is returned by get_first_cref_to() or previous call to get_next_cref_to() functions.

Returns

linear address of the next referencing instruction or BADADDR.