codegen_t Class Reference

Helper class to generate the initial microcode. More...

#include <hexrays.hpp>

Public Member Functions
virtual merror_t	analyze_prolog (const class qflow_chart_t &fc, const class bitset_t &reachable)=0
	Analyze prolog/epilog of the function to decompile. More...
virtual merror_t	gen_micro ()=0
	Generate microcode for one instruction. More...
virtual mreg_t	load_operand (int opnum, int flags=0)=0
	Generate microcode to load one operand. More...
virtual void	microgen_completed ()
	This method is called when the microcode generation is done. More...
virtual merror_t	prepare_gen_micro ()
	Setup internal data to handle new instruction. More...
virtual mreg_t	load_effective_address (int n, int flags=0)=0
	Generate microcode to calculate the address of a memory operand. More...
virtual bool	store_operand (int n, const mop_t &mop, int flags=0, minsn_t **outins=nullptr)
	Generate microcode to store an operand. More...
minsn_t *	emit (mcode_t code, int width, uval_t l, uval_t r, uval_t d, int offsize)
	Emit one microinstruction. More...
minsn_t *	emit_micro_mvm (mcode_t code, op_dtype_t dtype, uval_t l, uval_t r, uval_t d, int offsize)
	Emit one microinstruction. More...
minsn_t *	emit (mcode_t code, const mop_t *l, const mop_t *r, const mop_t *d)
	Emit one microinstruction. More...

Public Attributes
mba_t *	mba
mblock_t *	mb = nullptr
insn_t	insn
char	ignore_micro = IM_NONE
cdg_insn_iterator_t	ii
size_t	reserved

Detailed Description

Helper class to generate the initial microcode.

Definition at line 5162 of file hexrays.hpp.

Constructor & Destructor Documentation

~codegen_t()

virtual codegen_t::~codegen_t ( )

virtual

Definition at line 5173 of file hexrays.hpp.

Member Function Documentation

analyze_prolog()

virtual merror_t codegen_t::analyze_prolog ( const class qflow_chart_t &  fc, const class bitset_t &  reachable  )

pure virtual

Analyze prolog/epilog of the function to decompile.

If prolog is found, allocate and fill 'mba->pi' structure.

Parameters

fc	flow chart
reachable	bitmap of reachable blocks

Returns

error code

emit() [1/2]

minsn_t * codegen_t::emit	(	mcode_t	code,
		const mop_t *	l,
		const mop_t *	r,
		const mop_t *	d
	)

Emit one microinstruction.

This variant accepts pointers to operands. It is more difficult to use but permits to create virtually any instruction. Operands may be nullptr when it makes sense.

Definition at line 11499 of file hexrays.hpp.

emit() [2/2]

minsn_t * codegen_t::emit	(	mcode_t	code,
		int	width,
		uval_t	l,
		uval_t	r,
		uval_t	d,
		int	offsize
	)

Emit one microinstruction.

The L, R, D arguments usually mean the register number. However, they depend on CODE. For example:

• for m_goto and m_jcnd L is the target address
• for m_ldc L is the constant value to load

  Parameters

  code	instruction opcode
  width	operand size in bytes
  l	left operand
  r	right operand
  d	destination operand
  offsize	for ldx/stx, the size of the offset operand for ldc, operand number of the constant value -1, set the FP instruction (e.g. for m_mov)

  Returns

  created microinstruction. can be nullptr if the instruction got immediately optimized away.

Definition at line 11493 of file hexrays.hpp.

emit_micro_mvm()

minsn_t * codegen_t::emit_micro_mvm	(	mcode_t	code,
		op_dtype_t	dtype,
		uval_t	l,
		uval_t	r,
		uval_t	d,
		int	offsize
	)

Emit one microinstruction.

This variant takes a data type not a size.

Definition at line 5249 of file hexrays.hpp.

gen_micro()

virtual merror_t codegen_t::gen_micro ( )

pure virtual

Generate microcode for one instruction.

The instruction is in INSN

Returns

MERR_OK - all ok MERR_BLOCK - all ok, need to switch to new block MERR_BADBLK - delete current block and continue other error codes are fatal

load_effective_address()

virtual mreg_t codegen_t::load_effective_address ( int  n, int  flags = 0  )

pure virtual

Generate microcode to calculate the address of a memory operand.

Parameters

n	- number of INSN operand
flags	- reserved for future use

Returns

register containing the operand address. mr_none - failed (not a memory operand)

load_operand()

virtual mreg_t codegen_t::load_operand ( int  opnum, int  flags = 0  )

pure virtual

Generate microcode to load one operand.

Parameters

opnum	number of INSN operand
flags	reserved for future use

Returns

register containing the operand.

microgen_completed()

virtual void codegen_t::microgen_completed ( )

virtual

This method is called when the microcode generation is done.

Definition at line 5201 of file hexrays.hpp.

prepare_gen_micro()

virtual merror_t codegen_t::prepare_gen_micro ( )

virtual

Setup internal data to handle new instruction.

This method should be called before calling gen_micro(). Usually gen_micro() is called by the decompiler. You have to call this function explicitly only if you yourself call gen_micro(). The instruction is in INSN

Returns

MERR_OK - all ok other error codes are fatal

Definition at line 5210 of file hexrays.hpp.

References MERR_OK.

store_operand()

virtual bool codegen_t::store_operand ( int  n, const mop_t &  mop, int  flags = 0, minsn_t **  outins = nullptr  )

virtual

Generate microcode to store an operand.

In case of success an arbitrary number of instructions can be generated (and even no instruction if the source and target are the same)

Parameters

n	- number of target INSN operand
mop	- operand to be stored
flags	- reserved for future use
outins	- (OUT) the last generated instruction

Returns

success

Member Data Documentation

ignore_micro

char codegen_t::ignore_micro = IM_NONE

Definition at line 5168 of file hexrays.hpp.

ii

cdg_insn_iterator_t codegen_t::ii

Definition at line 5169 of file hexrays.hpp.

insn

insn_t codegen_t::insn

Definition at line 5167 of file hexrays.hpp.

mb

mblock_t* codegen_t::mb = nullptr

Definition at line 5166 of file hexrays.hpp.

mba

mba_t* codegen_t::mba

Definition at line 5165 of file hexrays.hpp.

reserved

size_t codegen_t::reserved

Definition at line 5170 of file hexrays.hpp.