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2021-10-31 21:20:46 +02:00

75 lines
2.0 KiB
C++

#ifndef __BACKTRACK_HPP__
#define __BACKTRACK_HPP__
#include <pro.h>
#include <idp.hpp>
enum btsource_t
{
BT_NONE = 0,
BT_STACK,
BT_A,
BT_X,
BT_Y,
BT_DP
};
/**
* Walk instructions up, and try and determine what's the
* (size * 8)-bits value we're looking for.
*
* For example, let's assume we have the following sequence
* of instructions:
* .05:8001 PHK
* .05:8002 PLB
* We'll call:
* backtrack_value(0x58002, 1, BT_STACK).
*
* A more complex example is this:
* .C0:0024 A2 00 00 LDX #0
* .C0:0027 DA PHX
* .C0:0028 2B PLD
* .C0:0029 7B TDC
* .C0:002A 48 PHA
* .C0:002B AB PLB
* We'll call:
* backtrack_value(0xc0002b, 1, BT_STACK), which will call
* backtrack_value(0xc0002a, 1, BT_A), which will call
* backtrack_value(0xc00029, 1, BT_D), which will call
* backtrack_value(0xc00028, 2, BT_STACK), which will call
* backtrack_value(0xc00027, 2, BT_X), which has an immediate value that we can use. Bingo.
*
* Backtracking will, of course, stop if we hit the top
* of a function, as it doesn't make much sense to keep
* moving up.
*
* from_ea : The address from which we'll be analyzing up.
* size : The size, in bytes, of the data we're looking for.
* source : The register/stack that holds the value.
*
* returns : The value.
*/
int32 backtrack_value(ea_t from_ea, uint8 size, btsource_t source);
/**
* Walk instructions up, until an instruction with the given type
* is found.
*
* Backtracking will, of course, stop if we hit the top
* of a function, as it doesn't make much sense to keep
* moving up.
*
* from_ea : The address from which we'll be analyzing up.
* itype : The instruction type.
*
* returns : The address of the found instruction, or BADADDR
* if not found.
*/
ea_t backtrack_prev_ins(ea_t from_ea, m65_itype_t itype);
#endif