FPO_DATA

The FPO_DATA structure represents the stack frame layout for a function on an x86 computer when frame pointer omission (FPO) optimization is used. The structure is used to locate the base of the call frame.

typedef struct _FPO_DATA {
    DWORD ulOffStart; 
    DWORD cbProcSize; 
    DWORD cdwLocals; 
    WORD cdwParams;  
    WORD cbProlog : 8; 
    WORD cbRegs   : 3; 
    WORD fHasSEH  : 1; 
    WORD fUseBP   : 1; 
    WORD reserved : 1; 
    WORD cbFrame  : 2; 
} FPO_DATA, *PFPO_DATA;

Members

ulOffStart

Offset of the first byte of the function code.

cbProcSize

Number of bytes in the function.

cdwLocals

Number of local variables, in DWORDs.

cdwParams

Size of the parameters, in DWORDs.

cbProlog

Number of bytes in the function prolog code.

cbRegs

Number of registers saved.

fHasSEH

Indicates whether the function uses structured exception handling.

fUseBP

Indicates whether the EBP register has been allocated.

reserved

Reserved for future use.

cbFrame

Indicates the frame type.

Type	Meaning
FRAME_FPO	FPO frame
FRAME_TRAP	Trap frame
FRAME_TSS	TSS frame
FRAME_NONFPO	Non-FPO frame

Requirements

  Windows NT/2000: Requires Windows NT 4.0 or later.
  Windows 95/98: Requires Windows 95 or later. Available as a redistributable for Windows 95.
  Header: Declared in Winnt.h; include Windows.h.

See Also

Image Help Library Overview, ImageHlp Structures, FunctionTableAccessProc, STACKFRAME, SymFunctionTableAccess