Package ghidra.app.util.bin.format.dwarf.expression

Class DWARFExpressionEvaluator

java.lang.Object

ghidra.app.util.bin.format.dwarf.expression.DWARFExpressionEvaluator

public class DWARFExpressionEvaluator
extends Object

Evaluates a DWARFExpression.

If an instruction needs a value in a register or memory location, the current DWARFExpressionEvaluator.ValueReader callback will be called to fetch the value. The default implementation is to throw an exception, but future work may plug in a constant propagation callback.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static interface	DWARFExpressionEvaluator.ValueReader

Constructor Summary

Constructors

Constructor	Description
DWARFExpressionEvaluator(DWARFCompilationUnit cu)

Method Summary

Modifier and Type	Method	Description
void	evaluate(byte[] exprBytes)	Executes the instructions found in the expression.
void	evaluate(byte[] exprBytes, long... stackArgs)	Executes the instructions found in the expression.
void	evaluate(DWARFExpression expr)
void	evaluate(DWARFExpression expr, long... stackArgs)	Executes the instructions found in the expression.
DWARFCompilationUnit	getDWARFCompilationUnit()
DWARFExpression	getExpr()
int	getMaxStepCount()
int	getPtrSize()
boolean	hasNext()	Returns true if there are instructions that can be evaluated.
boolean	isEmpty()
Object	peek()	Peek at the top value of the stack.
Object	pop()	Pop the top value off the stack.
long	popLong()	Pop the top value off the stack, and coerce it into a scalar long.
Scalar	popScalar()	Pop the top value off the stack, and coerce it into a scalar.
Varnode	popVarnode()	Pop the top value off the stack, and coerce it into a varnode.
void	push(boolean b)
void	push(long l)
void	push(Address addr)
void	push(Register reg)
void	push(Object val)
void	setExpression(DWARFExpression expr)	Sets the current expression.
void	setFrameBaseStackLocation(int offset)
void	setFrameBaseVal(Varnode frameBaseVal)
void	setMaxStepCount(int maxStepCount)
void	setValReader(DWARFExpressionEvaluator.ValueReader valReader)
boolean	step()	Evaluates the next instruction in the expression.
String	toString()
DWARFExpressionEvaluator.ValueReader	withStaticStackRegisterValues(Integer stackOffset, Integer stackFrameOffset)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Details

DWARFExpressionEvaluator

public DWARFExpressionEvaluator(DWARFCompilationUnit cu)

Method Details

getDWARFCompilationUnit

public DWARFCompilationUnit getDWARFCompilationUnit()

getExpr

public DWARFExpression getExpr()

isEmpty

public boolean isEmpty()

getPtrSize

public int getPtrSize()

setFrameBaseStackLocation

public void setFrameBaseStackLocation(int offset)

setFrameBaseVal

public void setFrameBaseVal(Varnode frameBaseVal)

setValReader

public void setValReader(DWARFExpressionEvaluator.ValueReader valReader)

withStaticStackRegisterValues

public DWARFExpressionEvaluator.ValueReader withStaticStackRegisterValues(Integer stackOffset,
 Integer stackFrameOffset)

getMaxStepCount

public int getMaxStepCount()

setMaxStepCount

public void setMaxStepCount(int maxStepCount)

push

public void push(Address addr)

push

public void push(Register reg)

push

public void push(boolean b)

push

public void push(long l)

push

public void push(Object val)

peek

public Object peek()
            throws DWARFExpressionException

Peek at the top value of the stack.

Returns:

top value of the stack

Throws:

DWARFExpressionException - if stack is empty

pop

public Object pop()
           throws DWARFExpressionException

Pop the top value off the stack.

Returns:

top value of the stack

Throws:

DWARFExpressionException - if stack is empty

popScalar

public Scalar popScalar()
                 throws DWARFExpressionException

Pop the top value off the stack, and coerce it into a scalar.

Returns:

top value of the stack, as a scalar

Throws:

DWARFExpressionException - if stack is empty or value can not be used as a scalar

popVarnode

public Varnode popVarnode()
                   throws DWARFExpressionException

Pop the top value off the stack, and coerce it into a varnode.

Returns:

top value of the stack, as a varnode

Throws:

DWARFExpressionException - if stack is empty or value can not be used as a varnode

popLong

public long popLong()
             throws DWARFExpressionException

Pop the top value off the stack, and coerce it into a scalar long.

Returns:

top value of the stack, as a scalar long

Throws:

DWARFExpressionException - if stack is empty or value can not be used as a long

evaluate

public void evaluate(byte[] exprBytes)
              throws DWARFExpressionException

Executes the instructions found in the expression.

Parameters:

exprBytes - raw bytes of the expression

Throws:

DWARFExpressionException - if error

evaluate

public void evaluate(byte[] exprBytes,
 long... stackArgs)
              throws DWARFExpressionException

Executes the instructions found in the expression.

Parameters:

exprBytes - raw bytes of the expression

stackArgs - any values to push onto the stack before execution

Throws:

DWARFExpressionException - if error

setExpression

public void setExpression(DWARFExpression expr)

Sets the current expression.

Parameters:

expr - DWARFExpression

hasNext

public boolean hasNext()

Returns true if there are instructions that can be evaluated.

Returns:

true if there are instructions that can be evaluated

step

public boolean step()
             throws DWARFExpressionException

Evaluates the next instruction in the expression.

Returns:

true if there are more instructions

Throws:

DWARFExpressionException - if error

evaluate

public void evaluate(DWARFExpression expr,
 long... stackArgs)
              throws DWARFExpressionException

Executes the instructions found in the expression.

Parameters:

expr - DWARFException to evaluate

stackArgs - - pushed 0..N, so stackArgs[0] will be deepest, stackArgs[N] will be topmost.

Throws:

DWARFExpressionException - if error

evaluate

public void evaluate(DWARFExpression expr)
              throws DWARFExpressionException

Throws:

DWARFExpressionException

toString

public String toString()

Overrides:

toString in class Object