com.google.javascript.jscomp

Class NameBasedDefinitionProvider

java.lang.Object

com.google.javascript.jscomp.NameBasedDefinitionProvider

All Implemented Interfaces:

CompilerPass

Direct Known Subclasses:

DefinitionUseSiteFinder

public class NameBasedDefinitionProvider
extends Object
implements CompilerPass

Simple name-based definition gatherer that implements DefinitionProvider.

It treats all variable writes as happening in the global scope and treats all objects as capable of having the same set of properties. The current implementation only handles definitions whose right hand side is an immutable value or function expression. All complex definitions are treated as unknowns.

This definition simply uses the variable name to determine a new definition site so potentially it could return multiple definition sites for a single variable. Although we could use the type system to make this more accurate, in practice after disambiguate properties has run, names are unique enough that this works well enough to accept the performance gain.

Field Summary

Fields

Modifier and Type	Field and Description
protected boolean	allowComplexFunctionDefs
protected AbstractCompiler	compiler
protected Map<Node,com.google.javascript.jscomp.DefinitionSite>	definitionNodeByDefinitionSite
protected Set<Node>	definitionNodes
protected boolean	hasProcessBeenRun
protected com.google.common.collect.Multimap<String,com.google.javascript.jscomp.DefinitionsRemover.Definition>	nameDefinitionMultimap

Constructor Summary

Constructors

Constructor and Description
NameBasedDefinitionProvider(AbstractCompiler compiler, boolean allowComplexFunctionDefs)

Method Summary

Modifier and Type	Method and Description
com.google.javascript.jscomp.DefinitionSite	getDefinitionForFunction(Node function)
Collection<com.google.javascript.jscomp.DefinitionSite>	getDefinitionSites() Returns the collection of definition sites found during traversal.
Collection<com.google.javascript.jscomp.DefinitionsRemover.Definition>	getDefinitionsReferencedAt(Node useSite) Returns a collection of definitions that characterize the possible values of a variable or property.
protected static String	getSimplifiedName(Node node) Extract a name from a node.
void	process(Node externs, Node source) Process the JS with root node root.

Methods inherited from class java.lang.Object

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

Field Detail

nameDefinitionMultimap

protected final com.google.common.collect.Multimap<String,com.google.javascript.jscomp.DefinitionsRemover.Definition> nameDefinitionMultimap

definitionNodeByDefinitionSite

protected final Map<Node,com.google.javascript.jscomp.DefinitionSite> definitionNodeByDefinitionSite

definitionNodes

protected final Set<Node> definitionNodes

compiler

protected final AbstractCompiler compiler

allowComplexFunctionDefs

protected final boolean allowComplexFunctionDefs

hasProcessBeenRun

protected boolean hasProcessBeenRun

Constructor Detail

NameBasedDefinitionProvider

public NameBasedDefinitionProvider(AbstractCompiler compiler,
                                   boolean allowComplexFunctionDefs)

Method Detail

process

public void process(Node externs,
                    Node source)

Description copied from interface: CompilerPass

Process the JS with root node root. Can modify the contents of each Node tree

Specified by:

process in interface CompilerPass

Parameters:

externs - Top of external JS tree

source - Top of JS tree

getDefinitionsReferencedAt

public Collection<com.google.javascript.jscomp.DefinitionsRemover.Definition> getDefinitionsReferencedAt(Node useSite)

Returns a collection of definitions that characterize the possible values of a variable or property. If information is unavailable or incomplete, return null. This function should never return an empty collection.

Returns:

non-empty definition collection, or null.

getSimplifiedName

protected static String getSimplifiedName(Node node)

Extract a name from a node. In the case of GETPROP nodes, replace the namespace or object expression with "this" for simplicity and correctness at the expense of inefficiencies due to higher chances of name collisions.

TODO(user) revisit. it would be helpful to at least use fully qualified names in the case of namespaces. Might not matter as much if this pass runs after CollapseProperties.

getDefinitionSites

public Collection<com.google.javascript.jscomp.DefinitionSite> getDefinitionSites()

Returns the collection of definition sites found during traversal.

Returns:

definition site collection.

getDefinitionForFunction

public com.google.javascript.jscomp.DefinitionSite getDefinitionForFunction(Node function)