You can use incremental compilation
to decrease the time it takes to compile an application or component
library with the application compilers. When incremental compilation
is enabled, the compiler inspects changes to the bytecode between
revisions and only recompiles the section of bytecode that has changed.
These sections of bytecode are also referred to as compilation units.
You enable incremental compilation by setting the incremental option
to true, as the following example shows:
mxmlc -incremental=true MyApp.mxml
Incremental compilation means that the compiler inspects your
code, determines which parts of the application are affected by
your changes, and only recompiles the newer classes and assets.
The Flex compilers generate many compilation units that do not change
between compilation cycles. It is possible that when you change
one part of your application, the change might not have any effect
on the bytecode of another.
As part of the incremental compilation process, the compiler
generates a cache file that lists the compilation units of your
application and information on your application’s structure. This
file is located in the same directory as the file that you are compiling.
For example, if my application is called MyApp.mxml, the cache file
is called MyApp.mxml.cache. This file helps the compiler determine
which parts of your application must be recompiled. One way to force
a complete recompile is to delete the cache file from the directory.
Incremental compilation can help reduce compile time on small
applications, but you achieve the biggest gains on larger applications.
The default value of the incremental compiler
option is true for the Flash Builder application
compiler. For the mxmlc command-line compiler, the default is false.