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frame.hpp File Reference

Routines to manipulate function stack frames, stack variables, register variables and local labels. More...

Classes

struct  stkpnt_t
 
struct  stkpnts_t
 
struct  regvar_t
 A register variable allows the user to rename a general processor register to a meaningful name. More...
 
struct  xreflist_entry_t
 An xref to an argument or variable located in a function's stack frame. More...
 

Macros

#define STKVAR_VALID_SIZE   0x0001
 x.dtyp contains correct variable type (for insns like 'lea' this bit must be off). More...
 
#define REGVAR_ERROR_OK   0
 all ok
 
#define REGVAR_ERROR_ARG   (-1)
 function arguments are bad
 
#define REGVAR_ERROR_RANGE   (-2)
 the definition range is bad
 
#define REGVAR_ERROR_NAME   (-3)
 the provided name(s) can't be accepted
 

Typedefs

typedef qvector< xreflist_entry_txreflist_t
 vector of xrefs to variables in a function's stack frame
 

Enumerations

enum  frame_part_t { FPC_ARGS , FPC_RETADDR , FPC_SAVREGS , FPC_LVARS }
 Parts of a frame.
 

Functions

idaman bool ida_export add_frame (func_t *pfn, sval_t frsize, ushort frregs, asize_t argsize)
 Add function frame. More...
 
idaman bool ida_export del_frame (func_t *pfn)
 Delete a function frame. More...
 
idaman bool ida_export set_frame_size (func_t *pfn, asize_t frsize, ushort frregs, asize_t argsize)
 Set size of function frame. More...
 
idaman asize_t ida_export get_frame_size (const func_t *pfn)
 Get full size of a function frame. More...
 
idaman int ida_export get_frame_retsize (const func_t *pfn)
 Get size of function return address. More...
 
idaman void ida_export get_frame_part (range_t *range, const func_t *pfn, frame_part_t part)
 Get offsets of the frame part in the frame. More...
 
ea_t frame_off_args (const func_t *pfn)
 Get starting address of arguments section.
 
ea_t frame_off_retaddr (const func_t *pfn)
 Get starting address of return address section.
 
ea_t frame_off_savregs (const func_t *pfn)
 Get starting address of saved registers section.
 
ea_t frame_off_lvars (const func_t *pfn)
 Get start address of local variables section.
 
idaman struc_t *ida_export get_frame (const func_t *pfn)
 Get pointer to function frame. More...
 
struc_tget_frame (ea_t ea)
 Get pointer to function frame. More...
 
sval_t soff_to_fpoff (func_t *pfn, uval_t soff)
 Convert struct offsets into fp-relative offsets. More...
 
idaman bool ida_export update_fpd (func_t *pfn, asize_t fpd)
 Update frame pointer delta. More...
 
idaman bool ida_export set_purged (ea_t ea, int nbytes, bool override_old_value)
 Set the number of purged bytes for a function or data item (funcptr). More...
 
idaman ea_t ida_export get_func_by_frame (tid_t frame_id)
 Get function by its frame id. More...
 
idaman member_t *ida_export get_frame_member_by_id (qstring *out_mname, struc_t **out_fptr, tid_t mid)
 Check if the specified member id points to a frame member.
 
idaman member_t *ida_export get_stkvar (sval_t *actval, const insn_t &insn, const op_t &x, sval_t v)
 Get pointer to stack variable. More...
 
idaman bool ida_export add_stkvar (const insn_t &insn, const op_t &x, sval_t v, int flags)
 Automatically add stack variable if doesn't exist. More...
 
idaman bool ida_export define_stkvar (func_t *pfn, const char *name, sval_t off, flags64_t flags, const opinfo_t *ti, asize_t nbytes)
 Define/redefine a stack variable. More...
 
idaman ssize_t ida_export build_stkvar_name (qstring *buf, const func_t *pfn, sval_t v)
 Build automatic stack variable name. More...
 
idaman ea_t ida_export calc_stkvar_struc_offset (func_t *pfn, const insn_t &insn, int n)
 Calculate offset of stack variable in the frame structure. More...
 
idaman int ida_export delete_wrong_frame_info (func_t *pfn, bool idaapi should_reanalyze(const insn_t &insn))
 Find and delete wrong frame info. More...
 
idaman void ida_export free_regvar (struct regvar_t *v)
 
idaman int ida_export add_regvar (func_t *pfn, ea_t ea1, ea_t ea2, const char *canon, const char *user, const char *cmt)
 Define a register variable. More...
 
idaman regvar_t *ida_export find_regvar (func_t *pfn, ea_t ea1, ea_t ea2, const char *canon, const char *user)
 Find a register variable definition (powerful version). More...
 
regvar_tfind_regvar (func_t *pfn, ea_t ea, const char *canon)
 Find a register variable definition. More...
 
bool has_regvar (func_t *pfn, ea_t ea)
 Is there a register variable definition? More...
 
idaman int ida_export rename_regvar (func_t *pfn, regvar_t *v, const char *user)
 Rename a register variable. More...
 
idaman int ida_export set_regvar_cmt (func_t *pfn, regvar_t *v, const char *cmt)
 Set comment for a register variable. More...
 
idaman int ida_export del_regvar (func_t *pfn, ea_t ea1, ea_t ea2, const char *canon)
 Delete a register variable definition. More...
 
idaman bool ida_export add_auto_stkpnt (func_t *pfn, ea_t ea, sval_t delta)
 Add automatic SP register change point. More...
 
idaman bool ida_export add_user_stkpnt (ea_t ea, sval_t delta)
 Add user-defined SP register change point. More...
 
idaman bool ida_export del_stkpnt (func_t *pfn, ea_t ea)
 Delete SP register change point. More...
 
idaman sval_t ida_export get_spd (func_t *pfn, ea_t ea)
 Get difference between the initial and current values of ESP. More...
 
idaman sval_t ida_export get_effective_spd (func_t *pfn, ea_t ea)
 Get effective difference between the initial and current values of ESP. More...
 
idaman sval_t ida_export get_sp_delta (func_t *pfn, ea_t ea)
 Get modification of SP made at the specified location. More...
 
idaman bool ida_export set_auto_spd (func_t *pfn, ea_t ea, sval_t new_spd)
 Add such an automatic SP register change point so that at EA the new cumulative SP delta (that is, the difference between the initial and current values of SP) would be equal to NEW_SPD. More...
 
idaman bool ida_export recalc_spd (ea_t cur_ea)
 Recalculate SP delta for an instruction that stops execution. More...
 
idaman bool ida_export recalc_spd_for_basic_block (func_t *pfn, ea_t cur_ea)
 Recalculate SP delta for the current instruction. More...
 
idaman void ida_export build_stkvar_xrefs (xreflist_t *out, func_t *pfn, const member_t *mptr)
 Fill 'out' with a list of all the xrefs made from function 'pfn', to the argument or variable 'mptr' in 'pfn's stack frame. More...
 

Detailed Description

Routines to manipulate function stack frames, stack variables, register variables and local labels.

The frame is represented as a structure:

  +------------------------------------------------+
  | function arguments                             |
  +------------------------------------------------+
  | return address (isn't stored in func_t)        |
  +------------------------------------------------+
  | saved registers (SI, DI, etc - func_t::frregs) |
  +------------------------------------------------+ <- typical BP
  |                                                |  |
  |                                                |  | func_t::fpd
  |                                                |  |
  |                                                | <- real BP
  | local variables (func_t::frsize)               |
  |                                                |
  |                                                |
  +------------------------------------------------+ <- SP

To access the structure of a function frame, use:

Function Documentation

◆ add_frame()

idaman bool ida_export add_frame ( func_t pfn,
sval_t  frsize,
ushort  frregs,
asize_t  argsize 
)

Add function frame.

Parameters
pfnpointer to function structure
frsizesize of function local variables
frregssize of saved registers
argsizesize of function arguments range which will be purged upon return. this parameter is used for __stdcall and __pascal calling conventions. for other calling conventions please pass 0.
Return values
1ok
0failed (no function, frame already exists)

◆ del_frame()

idaman bool ida_export del_frame ( func_t pfn)

Delete a function frame.

Parameters
pfnpointer to function structure
Returns
success

◆ set_frame_size()

idaman bool ida_export set_frame_size ( func_t pfn,
asize_t  frsize,
ushort  frregs,
asize_t  argsize 
)

Set size of function frame.

Note: The returned size may not include all stack arguments. It does so only for __stdcall and __fastcall calling conventions. To get the entire frame size for all cases use get_struc_size(get_frame(pfn)).

Parameters
pfnpointer to function structure
frsizesize of function local variables
frregssize of saved registers
argsizesize of function arguments that will be purged from the stack upon return
Returns
success

◆ get_frame_size()

idaman asize_t ida_export get_frame_size ( const func_t pfn)

Get full size of a function frame.

This function takes into account size of local variables + size of saved registers + size of return address + number of purged bytes. The purged bytes correspond to the arguments of the functions with __stdcall and __fastcall calling conventions.

Parameters
pfnpointer to function structure, may be nullptr
Returns
size of frame in bytes or zero

◆ get_frame_retsize()

idaman int ida_export get_frame_retsize ( const func_t pfn)

Get size of function return address.

Parameters
pfnpointer to function structure, can't be nullptr

◆ get_frame_part()

idaman void ida_export get_frame_part ( range_t range,
const func_t pfn,
frame_part_t  part 
)

Get offsets of the frame part in the frame.

Parameters
rangepointer to the output buffer with the frame part start/end(exclusive) offsets, can't be nullptr
pfnpointer to function structure, can't be nullptr
partframe part

◆ get_frame() [1/2]

idaman struc_t *ida_export get_frame ( const func_t pfn)

Get pointer to function frame.

Parameters
pfnpointer to function structure

◆ get_frame() [2/2]

struc_t * get_frame ( ea_t  ea)
inline

Get pointer to function frame.

Parameters
eaany address in the function

◆ soff_to_fpoff()

sval_t soff_to_fpoff ( func_t pfn,
uval_t  soff 
)
inline

Convert struct offsets into fp-relative offsets.

This function converts the offsets inside the struc_t object into the frame pointer offsets (for example, EBP-relative).

◆ update_fpd()

idaman bool ida_export update_fpd ( func_t pfn,
asize_t  fpd 
)

Update frame pointer delta.

Parameters
pfnpointer to function structure
fpdnew fpd value. cannot be bigger than the local variable range size.
Returns
success

◆ set_purged()

idaman bool ida_export set_purged ( ea_t  ea,
int  nbytes,
bool  override_old_value 
)

Set the number of purged bytes for a function or data item (funcptr).

This function will update the database and plan to reanalyze items referencing the specified address. It works only for processors with PR_PURGING bit in 16 and 32 bit modes.

Parameters
eaaddress of the function of item
nbytesnumber of purged bytes
override_old_valuemay overwrite old information about purged bytes
Returns
success

◆ get_func_by_frame()

idaman ea_t ida_export get_func_by_frame ( tid_t  frame_id)

Get function by its frame id.

Warning
this function works only with databases created by IDA > 5.6
Parameters
frame_idid of the function frame
Returns
start address of the function or BADADDR

◆ get_stkvar()

idaman member_t *ida_export get_stkvar ( sval_t actval,
const insn_t insn,
const op_t x,
sval_t  v 
)

Get pointer to stack variable.

Parameters
actvalactual value used to fetch stack variable this pointer may point to 'v'
insnthe instruction
xreference to instruction operand
vimmediate value in the operand (usually x.addr)
Returns
nullptr or ptr to stack variable

◆ add_stkvar()

idaman bool ida_export add_stkvar ( const insn_t insn,
const op_t x,
sval_t  v,
int  flags 
)

Automatically add stack variable if doesn't exist.

Processor modules should use insn_t::create_stkvar().

Parameters
insnthe instruction
xreference to instruction operand
vimmediate value in the operand (usually x.addr)
flagsAdd stkvar flags
Returns
success

◆ define_stkvar()

idaman bool ida_export define_stkvar ( func_t pfn,
const char *  name,
sval_t  off,
flags64_t  flags,
const opinfo_t ti,
asize_t  nbytes 
)

Define/redefine a stack variable.

Parameters
pfnpointer to function
namevariable name, nullptr means autogenerate a name
offoffset of the stack variable in the frame. negative values denote local variables, positive - function arguments.
flagsvariable type flags (byte_flag() for a byte variable, for example)
tiadditional type information (like offsets, structs, etc)
nbytesnumber of bytes occupied by the variable
Returns
success

◆ build_stkvar_name()

idaman ssize_t ida_export build_stkvar_name ( qstring buf,
const func_t pfn,
sval_t  v 
)

Build automatic stack variable name.

Parameters
bufpointer to buffer
pfnpointer to function (can't be nullptr!)
vvalue of variable offset
Returns
length of stack variable name or -1

◆ calc_stkvar_struc_offset()

idaman ea_t ida_export calc_stkvar_struc_offset ( func_t pfn,
const insn_t insn,
int  n 
)

Calculate offset of stack variable in the frame structure.

Parameters
pfnpointer to function (can't be nullptr!)
insnthe instruction
n0..UA_MAXOP-1 operand number -1 if error, return BADADDR
Returns
BADADDR if some error (issue a warning if stack frame is bad)

◆ delete_wrong_frame_info()

idaman int ida_export delete_wrong_frame_info ( func_t pfn,
bool idaapi   should_reanalyzeconst insn_t &insn 
)

Find and delete wrong frame info.

Namely, we delete:

  • unreferenced stack variable definitions
  • references to dead stack variables (i.e. operands displayed in red) these operands will be untyped and most likely displayed in hex. We also plan to reanalyze instruction with the stack frame references
    Parameters
    pfnpointer to the function
    should_reanalyzecallback to determine which instructions to reanalyze
    Returns
    number of deleted definitions

◆ add_auto_stkpnt()

idaman bool ida_export add_auto_stkpnt ( func_t pfn,
ea_t  ea,
sval_t  delta 
)

Add automatic SP register change point.

Parameters
pfnpointer to the function. may be nullptr.
ealinear address where SP changes. usually this is the end of the instruction which modifies the stack pointer ( insn_t::ea+ insn_t::size)
deltadifference between old and new values of SP
Returns
success

◆ add_user_stkpnt()

idaman bool ida_export add_user_stkpnt ( ea_t  ea,
sval_t  delta 
)

Add user-defined SP register change point.

Parameters
ealinear address where SP changes
deltadifference between old and new values of SP
Returns
success

◆ del_stkpnt()

idaman bool ida_export del_stkpnt ( func_t pfn,
ea_t  ea 
)

Delete SP register change point.

Parameters
pfnpointer to the function. may be nullptr.
ealinear address
Returns
success

◆ get_spd()

idaman sval_t ida_export get_spd ( func_t pfn,
ea_t  ea 
)

Get difference between the initial and current values of ESP.

Parameters
pfnpointer to the function. may be nullptr.
ealinear address of the instruction
Returns
0 or the difference, usually a negative number. returns the sp-diff before executing the instruction.

◆ get_effective_spd()

idaman sval_t ida_export get_effective_spd ( func_t pfn,
ea_t  ea 
)

Get effective difference between the initial and current values of ESP.

This function returns the sp-diff used by the instruction. The difference between get_spd() and get_effective_spd() is present only for instructions like "pop [esp+N]": they modify sp and use the modified value.

Parameters
pfnpointer to the function. may be nullptr.
ealinear address
Returns
0 or the difference, usually a negative number

◆ get_sp_delta()

idaman sval_t ida_export get_sp_delta ( func_t pfn,
ea_t  ea 
)

Get modification of SP made at the specified location.

Parameters
pfnpointer to the function. may be nullptr.
ealinear address
Returns
0 if the specified location doesn't contain a SP change point. otherwise return delta of SP modification.

◆ set_auto_spd()

idaman bool ida_export set_auto_spd ( func_t pfn,
ea_t  ea,
sval_t  new_spd 
)

Add such an automatic SP register change point so that at EA the new cumulative SP delta (that is, the difference between the initial and current values of SP) would be equal to NEW_SPD.

Parameters
pfnpointer to the function. may be nullptr.
ealinear address of the instruction
new_spdnew value of the cumulative SP delta
Returns
success

◆ recalc_spd()

idaman bool ida_export recalc_spd ( ea_t  cur_ea)

Recalculate SP delta for an instruction that stops execution.

The next instruction is not reached from the current instruction. We need to recalculate SP for the next instruction.

This function will create a new automatic SP register change point if necessary. It should be called from the emulator (emu.cpp) when auto_state == AU_USED if the current instruction doesn't pass the execution flow to the next instruction.

Parameters
cur_ealinear address of the current instruction
Return values
1new stkpnt is added
0nothing is changed

◆ recalc_spd_for_basic_block()

idaman bool ida_export recalc_spd_for_basic_block ( func_t pfn,
ea_t  cur_ea 
)

Recalculate SP delta for the current instruction.

The typical code snippet to calculate SP delta in a proc module is:

if ( may_trace_sp() && pfn != nullptr )
  if ( !recalc_spd_for_basic_block(pfn, insn.ea) )
    trace_sp(pfn, insn);

where trace_sp() is a typical name for a function that emulates the SP change of an instruction.

Parameters
pfnpointer to the function
cur_ealinear address of the current instruction
Return values
truethe cumulative SP delta is set
falsethe instruction at CUR_EA passes flow to the next instruction. SP delta must be set as a result of emulating the current instruction.

◆ build_stkvar_xrefs()

idaman void ida_export build_stkvar_xrefs ( xreflist_t out,
func_t pfn,
const member_t mptr 
)

Fill 'out' with a list of all the xrefs made from function 'pfn', to the argument or variable 'mptr' in 'pfn's stack frame.

Parameters
outthe list of xrefs to fill.
pfnthe function to scan.
mptrthe argument/variable in pfn's stack frame.