com.google.javascript.jscomp

Class VariableVisibilityAnalysis

java.lang.Object

com.google.javascript.jscomp.VariableVisibilityAnalysis

All Implemented Interfaces:

CompilerPass

class VariableVisibilityAnalysis
extends java.lang.Object
implements CompilerPass

An analysis pass that determines the visibility of variables -- that is, whether a variable is truly local, a local captured by an inner scope, a parameter, or a global variable. SideEffectsAnalysis uses this class to partition a potentially infinite number of concrete storage locations into a (small) finite number of abstract storage locations based on a variable's storage visibility.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
(package private) static class	VariableVisibilityAnalysis.VariableVisibility

Field Summary

Fields

Modifier and Type	Field and Description
private AbstractCompiler	compiler
private java.util.Map<Node,VariableVisibilityAnalysis.VariableVisibility>	visibilityByDeclaringNameNode Maps the declaring name node for a variable to that variable's visibility.

Constructor Summary

Constructors

Constructor and Description
VariableVisibilityAnalysis(AbstractCompiler compiler)

Method Summary

Modifier and Type	Method and Description
VariableVisibilityAnalysis.VariableVisibility	getVariableVisibility(Node declaringNameNode) Returns the visibility of of a variable, given that variable's declaring name node.
void	process(Node externs, Node root) Determines the visibility class for each variable in root.
private static boolean	variableIsParameter(Var variable) Returns true if the variable is a formal parameter.

Methods inherited from class java.lang.Object

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

Field Detail

compiler

private AbstractCompiler compiler

visibilityByDeclaringNameNode

private java.util.Map<Node,VariableVisibilityAnalysis.VariableVisibility> visibilityByDeclaringNameNode

Maps the declaring name node for a variable to that variable's visibility.

Constructor Detail

VariableVisibilityAnalysis

public VariableVisibilityAnalysis(AbstractCompiler compiler)

Method Detail

getVariableVisibility

public VariableVisibilityAnalysis.VariableVisibility getVariableVisibility(Node declaringNameNode)

Returns the visibility of of a variable, given that variable's declaring name node. The name node's parent must be one of:

    Token.VAR (for a variable declaration)
    Token.FUNCTION (for a function declaration)
    Token.PARAM_LIST (for a function formal parameter)
 

The returned visibility will be one of:

    LOCAL_VARIABLE : the variable is a local variable used only in its
        declared scope
    CAPTURED_LOCAL_VARIABLE : A local variable that is used in a capturing
        closure
     PARAMETER_VARIABLE : the variable is a formal parameter
     GLOBAL_VARIABLE : the variable is declared in the global scope
  

Parameters:

declaringNameNode - The name node for a declaration.

process

public void process(Node externs,
                    Node root)

Determines the visibility class for each variable in root.

Specified by:

process in interface CompilerPass

Parameters:

externs - Top of external JS tree

root - Top of JS tree

variableIsParameter

private static boolean variableIsParameter(Var variable)

Returns true if the variable is a formal parameter.