com.google.javascript.jscomp

Class UnreachableCodeElimination

java.lang.Object

com.google.javascript.jscomp.UnreachableCodeElimination

All Implemented Interfaces:

CompilerPass

class UnreachableCodeElimination
extends java.lang.Object
implements CompilerPass

Removes dead code from a parse tree. The kinds of dead code that this pass removes are: - Any code following a return statement, such as the alert call in: if (x) { return; alert('unreachable'); }. - Statements that have no side effects, such as: a.b.MyClass.prototype.propertyName; or true;. That first kind of statement sometimes appears intentionally, so that prototype properties can be annotated using JSDoc without actually being initialized.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
private class	UnreachableCodeElimination.EliminationPass

Field Summary

Fields

Modifier and Type	Field and Description
private boolean	codeChanged
private AbstractCompiler	compiler
private static java.util.logging.Logger	logger
private boolean	removeNoOpStatements

Constructor Summary

Constructors

Constructor and Description
UnreachableCodeElimination(AbstractCompiler compiler, boolean removeNoOpStatements)

Method Summary

Modifier and Type	Method and Description
void	process(Node externs, Node toplevel) 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

logger

private static final java.util.logging.Logger logger

compiler

private final AbstractCompiler compiler

removeNoOpStatements

private final boolean removeNoOpStatements

codeChanged

private boolean codeChanged

Constructor Detail

UnreachableCodeElimination

UnreachableCodeElimination(AbstractCompiler compiler,
                           boolean removeNoOpStatements)

Method Detail

process

public void process(Node externs,
                    Node toplevel)

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

toplevel - Top of JS tree