com.google.gwt.dev.jjs.impl

Class Devirtualizer

java.lang.Object

com.google.gwt.dev.jjs.impl.Devirtualizer

public class Devirtualizer
extends Object

Devirtualization is the process of converting virtual method calls on instances that might be a JSO, a string or and array (like "obj.doFoo();") to static calls (like "SomeClass.doFoo__devirtual$(obj)). This transformation is done on arrays, strings and JSOs virtual method calls; as this objects do not have the virtual methods in their prototypes. The static version is a trampoline that decides how to dispatch the method. See https://code.google.com/p/google-web-toolkit/wiki/OverlayTypes for why this is done for JSOs.
To complete the transformation:

• 1. methods that need to be devirtualized must be turned into static functions.
• 2. all method calls to the original functions must be rerouted either to the new static version or to a static dispatcher trampoline function that is created by this pass.

These trampolines are created whether a call to the function exists for separate compiled modules to work. In a globally optimized build unused ones are pruned away.
This transform may NOT be run multiple times; it will create ever-expanding replacement expressions.

Field Summary

Fields

Modifier and Type	Field and Description
protected Map<JMethod,JMethod>	devirtualMethodByMethod Maps each Object instance methods (ie, Object.equals(Object)) onto its corresponding devirtualizing method.

Method Summary

Modifier and Type	Method and Description
static void	exec(JProgram program)
static boolean	isGetClassDevirtualized(JProgram program, JType type) Returns true if getClass() is devirtualized for type; used in ReplaceGetClassOverrides to avoid replacing getClass() methods that need trampolines.

Methods inherited from class java.lang.Object

equals, finalize, getClass, hashCode, toString

Field Detail

devirtualMethodByMethod

protected Map<JMethod,JMethod> devirtualMethodByMethod

Maps each Object instance methods (ie, Object.equals(Object)) onto its corresponding devirtualizing method.

Method Detail

exec

public static void exec(JProgram program)

isGetClassDevirtualized

public static boolean isGetClassDevirtualized(JProgram program,
                                              JType type)

Returns true if getClass() is devirtualized for type; used in ReplaceGetClassOverrides to avoid replacing getClass() methods that need trampolines.