scale.alias
Class AliasAnalysis

java.lang.Object
  scale.alias.AliasAnalysis

Direct Known Subclasses:

ShapiroHorowitz, Steensgaard

public abstract class AliasAnalysis
extends java.lang.Object

A class for computing aliases among variables.

$Id: AliasAnalysis.java,v 1.18 2005-02-07 21:27:10 burrill Exp $

Copyright 2008 by the Scale Compiler Group,
Department of Computer Science
University of Massachusetts,
Amherst MA. 01003, USA
All Rights Reserved.

Field Summary

static boolean	classTrace True if traces are to be performed.
protected boolean	trace

Constructor Summary

AliasAnalysis()

Method Summary

abstract void	addrAssign(AliasVar lhs, AliasVar addr) Compute aliases for the assignment of an address (x = &y).
abstract AliasVar	addVariable(Declaration decl) Add a variable into the the analyzer.
abstract AliasVar	addVariable(Declaration decl, AliasVar v) Add a variable into the analyzer and use some of the information from an existing alias variable.
abstract void	assignPtr(AliasVar ptr, AliasVar rhs) Compute aliases for assigning to a pointer (*x = y).
abstract void	functionCall(AliasVar lhs, AliasVar func, Vector<AliasVar> args) Compute aliases caused by a function call.
abstract void	functionDef(AliasVar func, Vector<AliasVar> params, AliasVar retval) Compute aliases for the formal parameters and return value of a function definition.
abstract void	heapAssign(AliasVar lhs) Compute aliases for assigning dynamically allocated memory.
abstract boolean	isContextSensitive() Return true if the analysis is context sensitive.
abstract boolean	isFlowSensitive() Return true if the analysis is flow sensitive.
abstract boolean	isInterProcedural() Return true if the analysis is interprocedural.
abstract void	opAssign(AliasVar lhs, Vector<AliasVar> opnds) Compute alias for an operation (x = op(y1,…,yN)).
abstract void	ptrAssign(AliasVar lhs, AliasVar ptr) Compute aliases for a pointer assignment (x = *y).
abstract void	simpleAssign(AliasVar lhs, AliasVar rhs) Compute aliases for assignment statement (x = y).

Methods inherited from class java.lang.Object

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

Field Detail

classTrace

public static boolean classTrace

True if traces are to be performed.

trace

protected boolean trace

Constructor Detail

AliasAnalysis

public AliasAnalysis()

Method Detail

isFlowSensitive

public abstract boolean isFlowSensitive()

Return true if the analysis is flow sensitive. That is, does the analysis care about statement order.

Returns:

true if the analysis is flow sensitive.

isContextSensitive

public abstract boolean isContextSensitive()

Return true if the analysis is context sensitive. That is, does the analysis care about function call context.

Returns:

true if the analysis is context sensitive.

isInterProcedural

public abstract boolean isInterProcedural()

Return true if the analysis is interprocedural. An analysis that is not interprocedural must make very simplifying assumptions at procedure calls. Note - by definition, a flow and context sensitive analysis is interprocedural.

addVariable

public abstract AliasVar addVariable(Declaration decl)

Add a variable into the the analyzer.

Parameters:

decl - is the name of the variable.

Returns:

the alias variable that represents the varaible.

addVariable

public abstract AliasVar addVariable(Declaration decl,
                                     AliasVar v)

Add a variable into the analyzer and use some of the information from an existing alias variable.

Returns:

the alias variable that represents the varaible.

simpleAssign

public abstract void simpleAssign(AliasVar lhs,
                                  AliasVar rhs)

Compute aliases for assignment statement (x = y).

Parameters:

lhs - the left hand side of the assignment (lvalue).

rhs - the righ hand side of the assignment (rvalue).

addrAssign

public abstract void addrAssign(AliasVar lhs,
                                AliasVar addr)

Compute aliases for the assignment of an address (x = &y).

Parameters:

lhs - is the left hand side of the assignment (lvalue).

addr - is the right hand side of the assignment (the address).

ptrAssign

public abstract void ptrAssign(AliasVar lhs,
                               AliasVar ptr)

Compute aliases for a pointer assignment (x = *y).

Parameters:

lhs - is the left hand side of the assignment.

ptr - is the right hand side of the assignment (the pointer).

opAssign

public abstract void opAssign(AliasVar lhs,
                              Vector<AliasVar> opnds)

Compute alias for an operation (x = op(y1,…,yN)).

Parameters:

lhs - is the left hand side of the assignment.

opnds - is the list of arguments of the operation.

heapAssign

public abstract void heapAssign(AliasVar lhs)

Compute aliases for assigning dynamically allocated memory.

Parameters:

lhs - is the left hand side of the assignment.

assignPtr

public abstract void assignPtr(AliasVar ptr,
                               AliasVar rhs)

Compute aliases for assigning to a pointer (*x = y).

Parameters:

ptr - the pointer representing the left hand side of the assignment.

rhs - the right hand side of the assignment.

functionDef

public abstract void functionDef(AliasVar func,
                                 Vector<AliasVar> params,
                                 AliasVar retval)

Compute aliases for the formal parameters and return value of a function definition.

Parameters:

func - the alias variable representing the function.

params - the alias variables representing the list of parameters.

retval - the alias variables representing the return value.

functionCall

public abstract void functionCall(AliasVar lhs,
                                  AliasVar func,
                                  Vector<AliasVar> args)

Compute aliases caused by a function call.

Parameters:

lhs - the alias variables representing the value returned by the function call.

func - the alias variables representing the function.

args - alias variables representing the arguments.