chord.analyses.alias
Class CtxtsAnalysis

java.lang.Object
  chord.project.analyses.JavaAnalysis
      chord.analyses.alias.CtxtsAnalysis

All Implemented Interfaces:

ITask

public class CtxtsAnalysis
extends JavaAnalysis

Analysis for pre-computing abstract contexts.

The goal of this analysis is to translate client-specified inputs concerning the desired kind of context sensitivity into relations that are subsequently consumed by context-sensitive may alias and call graph analyses.

This analysis allows:

• each method to be analyzed using a different kind of context sensitivity (one of context insensitivity, k-CFA, k-object-sensitivity, and copy-context-sensitivity),
• each local variable to be analyzed context sensitively or insensitively, and
• a different 'k' value to be used for each object allocation site and method call site.

This analysis can be called multiple times and in each invocation it can incorporate feedback from a client to adjust the precision of the points-to information and call graph computed subsequently by the may alias and call graph analyses. Clients can indicate in each invocation:

• Which methods must be analyzed context sensitively (in addition to those already being analyzed context sensitively in the previous invocation of this analysis) and using what kind of context sensitivity; the remaining methods will be analyzed context insensitively (that is, in the lone 'epsilon' context)
• Which local variables of reference type must be analyzed context sensitively (in addition to those already being analyzed context sensitively in the previous invocation of this analysis); the remaining ones will be analyzed context insensitively (that is, their points-to information will be tracked in the lone 'epsilon' context).
• The object alocation sites and method call sites whose 'k' values must be incremented (over those used in the previous invocation of this analysis).

Recognized system properties:

• chord.ctxt.kind: the kind of context sensitivity to use for each method (and all its locals). It may be 'ci' (context insensitive) or 'cs' (k-CFA).
• chord.inst.ctxt.kind: the kind of context sensitivity to use for each instance method (and all its locals). It may be 'ci' (context insensitive), 'cs' (k-CFA), or 'co' (k-object-sensitive).
• chord.stat.ctxt.kind: the kind of context sensitivity to use for each static method (and all its locsals). It may be one of 'ci' (context insensitive), 'cs' (k-CFA), or 'cc' (copy-context-sensitive).
• chord.kobj.k and chord.kcfa.k: the 'k' value to use for each object allocation site and each method call site, respectively.

This analysis outputs the following domains and relations:

• C: domain containing all abstract contexts
• CC: relation containing each pair (c,c2) such that c2 is all but the last element of context c
• CH: relation containing each (c,h) such that object allocation site h is the last element of abstract context c
• CI: relation containing each (c,i) such that call site i is the last element of abstract context c
• CVC: relation containing each (c,v,o) such that local v might point to object o in context c of its declaring method.
• CFC: relation containing each (o1,f,o2) such that instance field f of object o1 might point to object o2
• FC: relation containing each (f,o) such that static field f may point to object o
• CICM: relation containing each (c,i,c2,m) if invocation i in context c can reach method 2 (in context c2)
• rootCM: relation containing each (c,m) such that method m is an entry method in context c
• reachableCM: relation containing each (c,m) such that method m can be called in context c

Author:

Mayur Naik (mhn@cs.stanford.edu)

Field Summary

static int	CTXTCPY
static int	CTXTINS
static int[]	global_kcfaValue
static int[]	global_kobjValue
static int	KCFASEN
static int	KOBJSEN

Fields inherited from class chord.project.analyses.JavaAnalysis

consumes, controls, name, produces

Constructor Summary

CtxtsAnalysis()

Method Summary

static java.lang.String	getCspaKind()
void	run() Executes this analysis in a "classic" project.

Methods inherited from class chord.project.analyses.JavaAnalysis

getName, run, setName, toString

Methods inherited from class java.lang.Object

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

Field Detail

CTXTINS

public static final int CTXTINS

See Also:

Constant Field Values

KOBJSEN

public static final int KOBJSEN

See Also:

Constant Field Values

KCFASEN

public static final int KCFASEN

See Also:

Constant Field Values

CTXTCPY

public static final int CTXTCPY

See Also:

Constant Field Values

global_kobjValue

public static int[] global_kobjValue

global_kcfaValue

public static int[] global_kcfaValue

Constructor Detail

CtxtsAnalysis

public CtxtsAnalysis()

Method Detail

run

public void run()

Description copied from interface: ITask

Executes this analysis in a "classic" project. This method must usually not be called directly. The correct way to call it is to call ClassicProject.runTask(String) or ClassicProject.runTask(ITask), providing this analysis either by its name or its object.

Specified by:

run in interface ITask

Overrides:

run in class JavaAnalysis

getCspaKind

public static java.lang.String getCspaKind()