# AspectJ Ant Tasks

## Introduction

AspectJ contains a compiler, `ajc`, that can be run from Ant. Included in the `aspectjtools.jar` are Ant binaries to support three ways of running the compiler:

1. , a task to run the new AspectJ 1.1 compiler, which supports all the eclipse and ajc options, including incremental mode.

2. , an adapter class to run the new compiler using Javac tasks by setting the build.compiler property

3. , a task to run build scripts compatible with the AspectJ 1.0 tasks

This describes how to install and use the tasks and the adapter. For an example Ant script, see examples/build.xml.

## Installing Ant Tasks

Install Jakarta Ant 1.5.1: Please see the official Jakarta Ant website for more information and the 1.5.1 distribution. This release is source-compatible with Ant 1.3 and Ant 1.4, but the task sources must be compiled with those versions of the Ant libraries to be used under those versions of Ant. Sources are available under the Common Public License v. 1.0 at http://eclipse.org/aspectj.

In Ant, third-party tasks can be declared using a taskdef entry in the build script, to identify the name and classes. When declaring a task, include the `aspectjtools.jar` either in the taskdef classpath or in ${ANT_HOME}/lib where it will be added to the system class path by the ant script. You may specify the task script names directly, or use the "resource" attribute to specify the default names:

      <taskdef
          resource="org/aspectj/tools/ant/taskdefs/aspectjTaskdefs.properties"/>

The current resource file retains the name "ajc" for the Ajc10 task, and uses "iajc" for the AspectJ 1.1 task.

For more information on using Ant, please refer to Jakarta's documentation on integrating user-defined Ant tasks into builds.

## AjcTask (iajc)

This task uses the AspectJ 1.1 compiler ajc. The AspectJ compiler can be used like Javac to compile Java sources, but it can also compile AspectJ sources or weave binary aspects with Java bytecode. It can run in normal "batch" mode or in an "incremental" mode, where it only recompiles files it has to revisit. For more information on ajc, see .

Beyond the normal ajc 1.1 compiler options, this task also supports an experimental option for an incremental "tag" file, and it can copy resources from source directories or input jars to the output jar or directory.

This task is named iajc to avoid conflict with the 1.0 task ajc.

### AjcTask (iajc) Options

The following tables list the supported parameters. For any parameter specified as a Path, a single path can be specified directly as an attribute, multiple paths can be specified using a nested element of the same name, and a common path can be reused by defining it as a global and passing the id to the corresponding {name}ref attribute. See below for more details.

Most attributes and nested elements are optional. The compiler requires that the same version of `aspectjrt.jar` be specified on the classpath, and that some sources be be specified (using one or more of `sourceroots`, `injars`, `inpath`, `argfiles`, and/or `srcdir` (with patterns)). When in incremental mode, only `sourceroots` may be specified.

Boolean parameters default to `false` unless otherwise stated.

#### AjcTask (iajc) options for specifying sources

Attribute | Description
--- | ---
argfiles, argfilesRef () | An argument file contains a list of arguments read by the compiler. Each line is read into one element of the argument array and may include another argfile by reference.
sourceRoots, sourceRootsRef () | Directories containing source files (ending with .java or .aj) to compile.
srcdir () | Base directory of sources to compile, assuming there are . This approach uses the Ant process for matching .java files and is not compatible with incremental mode. Unless using filters to limit the sources included, use sourceroots instead.
injars, injarsRef () | Deprecated - use inpath instead. Read .class files for bytecode weaving from zip files (only).
inpath, inpathRef () | Read .class files for bytecode weaving from directories or zip files (like classpath).
classpath, classpathRef () | The classpath used by the sources being compiled. When compiling aspects, include the same version of the `aspectjrt.jar`.
bootclasspath, bootclasspathRef () | The bootclasspath specifies types to use instead of the invoking VM's when seeking types during compilation.
extDirs, extDirsRef () | The extension directories to use instead of those in the invoking VM when seeking types during compilation.
aspectPath, aspectPathRef () | Similar to classpath, aspectpath contains read-only, binary aspect libraries that are woven into sources but not included in the output. `aspectpath` accepts jar/zip files (but, unlike classpath, not directories).

#### AjcTask (iajc) options for specifying output

Attribute | Description
--- | ---
destDir | The directory in which to place the generated class files. Only one of `destDir` and `outJar` may be set.
outJar | The zip file in which to place the generated output class files. Only one of `destDir` and `outJar` may be set.
copyInjars | If true, copy all non-.class files from input jar(s) to the output jar or destination directory after the compile (or incremental compile) completes. In forked mode, this copies only after the process completes, not after incremental compiles.
sourceRootCopyFilter | When set, copy all files from the sourceroot directories to the output jar or destination directory except those specified in the filter pattern. The pattern should be compatible with an Ant fileset excludes filter; when using this, most developers pass `**/CVS/*,**/*.java` to exclude any CVS directories or source files.

#### AjcTask (iajc) options for specifying compiler behavior

Attribute | Description
--- | ---
fork | Run process in another VM. This gets the forking classpath either explicitly from a `forkclasspath` entry or by searching the task or system/Ant classpath for the first readable file with a name of the form `aspectj{-}tools{.*}.jar`. When forking you can specify the amount of memory used with `maxmem`. Fork cannot be used in incremental mode, unless using a tag file.
forkclasspath, forkclasspathRef () | Specify the classpath to use for the compiler when forking.
maxmem | The maximum memory to use for the new VM when fork is true. Values should have the same form as accepted by the VM, e.g., "128m".
incremental | incremental mode: Build once, then recompile only required source files when user provides input. Requires that source files be specified only using `sourceroots`. Incompatible with forking.
tagfile | incremental mode: Build once, then recompile only required source files when the tag file is updated, finally exiting when tag file is deleted. Requires that source files be specified only using `sourceroots`.
X | Set experimental option(s), using comma-separated list of accepted options (unlisted here). Options should not contain the leading X. XLint options should be specified using the xlint... entries.
Xnoweave | Experimental option to produce binaries that can only be used as input for the `-injars` or `-inpath` option. Usually aspects are compiled normally and put on the `aspectpath`.

#### AjcTask (iajc) options for specifying compiler side-effects and messages

Attribute | Description
--- | ---
emacssym | If true, emit `.ajesym` symbol files for Emacs support.
verbose | If true, emit compiler status messages during the compile.
Xlistfileargs | If true, emit list of file arguments during the compile (but behaves now like verbose).
version | If true, do not compile - just print AspectJ version.
help | If true, just print help for the command-line compiler.
Xlintwarnings | Same as `xlint:warning`: if true, set default level of all language usage messages to warning.
Xlint | Specify default level of all language usage messages to one of [`error warning ignore`].
XlintFile | Specify property file containing `name:level` associations setting level for language messages emitted during compilation. Any levels set override the default associations in `org/aspectj/weaver/XLintDefault.properties`.
failonerror | If true, throw BuildException to halt build if there are any compiler errors. If false, continue notwithstanding compile errors. Defaults to `true`.
messageHolderClass | Specify a class to use as the message holder for the compile process. The entry must be a fully-qualified name of a class resolveable from the task classpath complying with the `org.aspectj.bridge.IMessageHolder` interface and having a public no-argument constructor.

#### AjcTask (iajc) options for specifying Eclipse compiler options

Attribute | Description
--- | ---
nowarn | If true, same as `warn:none`.
deprecation | If true, same as `warn:deprecation`
warn | One or more comma-separated warning specifications from [`constructorName packageDefaultMethod deprecation, maskedCatchBlocks unusedLocals unusedArguments, unusedImports syntheticAccess assertIdentifier`].
debug | If true, same as `debug:lines,vars,source`
debugLevel | One or more comma-separated debug specifications from [`lines vars source`].
PreserveAllLocals | If true, code gen preserves all local variables (for debug purposes).
noimporterror | If true, emit no errors for unresolved imports.
referenceinfo | If true, compute reference info.
log | File to log compiler messages to.
encoding | Default source encoding format (per-file encoding not supported in Ant tasks).
proceedOnError | If true, keep compiling after errors encountered, dumping class files with problem methods.
progress | If true, emit progress (requires log).
time | If true, display speed information.
target | Specify target class file format as one of [`1.1 1.2`]. Defaults to 1.1 class file.
source | Set source compliance level to one of [`1.3 1.4`] (e.g., in 1.4 no assert identifiers and no import from default package). Defaults to 1.3 compliance level.
source | Set source assertion mode to one of [`1.3 1.4`]. Default depends on compliance mode.

### AjcTask matching parameters specified as nested elements

This task forms an implicit FileSet and supports all attributes of `<fileset>` (dir becomes srcdir) as well as the nested `<include>`, `<exclude>`, and `<patternset>` elements. These can be used to specify source files. However, it is better to use `sourceroots` to specify source directories unless using filters to exclude some files from compilation.

### AjcTask Path-like Structures

Some parameters are path-like structures containing one or more elements; these are `sourceroots`, `argfiles`, `injars`, `inpath`, `classpath`, `bootclasspath`, `forkclasspath`, and `aspectpath`. In all cases, these may be specified as nested elements, something like this:

        <iajc {attributes..} />
            <{name}>
                <pathelement path="{first-location}"/>
                <pathelement path="{second-location}"/>
                ...
            <{name}>
            ...
        </iajc>

As with other Path-like structures, they may be defined elsewhere and specified using the refid attribute:

        <path id="aspect.path">
            <pathelement path="${home}/lib/persist.jar"/>
            <pathelement path="${home}/lib/trace.jar"/>
        </path>
        ...
        <iajc {attributes..} />
            <aspectpath refid="aspect.path"/>
            ...
        </iajc>

The task also supports an attribute `{name}ref` for each such parameter. E.g., for `aspectpath`:

        <iajc {attributes..} aspectpathref="aspect.path"/>

### Sample of iajc task

A minimal build script defines the task and runs it, specifying the sources:

    <project name="simple-example" default="compile" >
      <taskdef
          resource="org/aspectj/tools/ant/taskdefs/aspectjTaskdefs.properties">
        <classpath>
          <pathelement location="${home.dir}/tools/aspectj/lib/aspectjtools.jar"/>
        </classpath>
      </taskdef>

      <target name="compile" >
        <iajc sourceroots="${home.dir}/ec/project/src"
            classpath="${home.dir}/tools/aspectj/lib/aspectjrt.jar"/>
      </target>
    </project>

Below is script with most everything in it. The compile process...

1. Runs in incremental mode, recompiling when the user hits return;

2. Reads all the sources from two directories;

3. Reads extrinsic module bytecode as input jar for weaving;

4. Uses a binary aspect library for persistence;

5. Outputs to an application jar; and

6. Copies resources from the input jar and source directories into the application jar.

When this target is built, the compiler will build once and then wait for input from the user. Messages are printed as usual. When the user has quit, then this runs the application.

      <target name="build-test" >
        <iajc outjar="${home.dir}/output/application.jar"
                injars="${home.dir}/build/module.jar"
                copyInjars="true"
                sourceRootCopyFilter="**/CVS/*,**/*.java"
                incremental="true" >
          <sourceroots>
            <pathelement location="${home.dir}/ec/project/src"/>
            <pathelement location="${home.dir}/ec/project/testsrc"/>
          </sourceroots>
          <aspectpath>
            <pathelement location="${home.dir}/ec/int/persist.jar"/>
          </aspectpath>
          <classpath>
            <pathelement location="${home.dir}/tools/aspectj/lib/aspectjrt.jar"/>
          </classpath>
        </iajc>

        <java classname="org.smart.app.Main">
          <classpath>
            <pathelement location="${home.dir}/tools/aspectj/lib/aspectjrt.jar"/>
            <pathelement location="${home.dir}/ec/int/persist.jar"/>
            <pathelement location="${home.dir}/output/application.jar"/>
          </classpath>
        </java>
      </target>

For an example of a build script, see ../examples/build.xml.

### Programmatically handling compiler messages

Users may specify a message holder to which the compiler will pass all messages as they are generated. This will override all of the normal message printing, but does not prevent the task from failing if exceptions were thrown or if failonerror is true and the compiler detected errors in the sources.

Handling messages programmatically could be useful when using the compiler to verify code. If aspects consist of declare [error|warning], then the compiler can act to detect invariants in the code being processed. For code to compare expected and actual messages, see the AspectJ testing module (which is not included in the binary distribution).

## Ajc11CompilerAdapter (javac)

This CompilerAdapter can be used in javac task calls by setting the `build.compiler` property. This enables users to to easily switch between the Javac and AspectJ compilers. However, the Javac task's pruning of source files prevents the adapter from doing a correct compile in some cases, so use AjcTask where possible.

### Sample of compiler adapter

To build using the adapter, put the `aspectjtools.jar` on the system/ant classpath (e.g., in `${ANT_HOME}/lib`) and define the `build.compiler` property as the fully-qualified name of the class, `org.aspectj.tools.ant.taskdefs.Ajc11CompilerAdapter`.

The AspectJ compiler should run for any compile using the Javac task (for options, see the Ant documentation for the Javac task). For example, the call below passes all out-of-date source files in the `src/org/aspectj` subdirectories to the `ajc` command along with the destination directory:

    -- command:

        cp aspectj1.1/lib/aspectjtools.jar ant/lib
        ant/bin/ant -Dbuild.compiler=org.aspectj.tools.ant.taskdefs.Ajc11CompilerAdapter ...

    -- task invocation in the build script:

      <javac srcdir="src" includes="org/aspectj/**/*.java" destdir="dest" />

To pass ajc-specific arguments, use a compilerarg entry.

    -- command

      Ant -Dbuild.compiler=org.aspectj.tools.ant.taskdefs.Ajc11CompilerAdapter

    -- build script

      <property name="ajc"
                  value="org.aspectj.tools.ant.taskdefs.Ajc11CompilerAdapter"/>

      <javac srcdir="src" includes="org/aspectj/**/*.java" destdir="dest" >
        <compilerarg compiler="${ajc}" line="-argfile src/args.lst"/>
      <javac/>

### Compiler adapter compilerarg options

The adapter supports any ajc command-line option passed using compilerarg, as well as the following options available only in AjcTask. Find more details on the following options in .

- `-Xmaxmem`: set maximum memory for forking (also settable in javac).

- `-Xlistfileargs`: list file arguments (also settable in javac).

- `-Xfailonerror`: throw BuildException on compiler error (also settable in javac).

- `-Xmessageholderclass`: specify fully-qualified name of class to use as the message holder.

- `-Xcopyinjars`: copy resources from any input jars to output (default behavior since 1.1.1)

- `-Xsourcerootcopyfilter {filter}`: copy resources from source directories to output (minus files specified in filter)

- `-Xtagfile {file}`: use file to control incremental compilation

- `-Xsrcdir {dir}`: add to list of ajc source roots (all source files will be included).

Special considerations when using Javac and compilerarg:

- The names above may differ slightly from what you might expect from AjcTask; use these forms when specifying compilerarg.

- By default the adapter will mimic the Javac task's copying of resource files by specifying `"**/CVS/*,**/*.java,**/*.aj"` for the sourceroot copy filter. To change this behavior, supply your own value (e.g., `"**/*"` to copy nothing).

- Warning - define the system property `build.compiler.clean` to compile all files, when available. Javac prunes the source file list of "up-to-date" source files based on the timestamps of corresponding .class files, and will not compile if no sources are out of date. This is wrong for ajc which requires all the files for each compile and which may refer indirectly to sources using argument files.

  To work around this, set the global property `build.compiler.clean`. This tells the compiler adapter to delete all .class files in the destination directory and re-execute the javac task so javac can recalculate the list of source files. e.g.,

        Ant -Dbuild.compiler=org.aspectj.tools.ant.taskdefs.Ajc11CompilerAdapter
            -Dbuild.compiler.clean=anything ...

  Caveats to consider when using this global `build.compiler.clean` property:

  1. If javac believes there are no out-of-date source files, then the adapter is never called and cannot clean up, and the "compile" will appear to complete successfully though it did nothing.

  2. Cleaning will makes stepwise build processes fail if they depend on the results of the prior compilation being in the same directory, since cleaning deletes all .class files.

  3. This clean process only permits one compile process at a time for each destination directory because it tracks recursion by writing a tag file to the destination directory.

  4. When running incrementally, the clean happens only before the initial compile.

## Ajc10 (ajc)

This task handles the same arguments as those used by the AspectJ 1.0 task. This should permit those with existing build scripts using the Ajc Ant task to continue using the same scripts when compiling with 1.1. This will list any use of options no longer supported in 1.1 (e.g., `lenient, strict, workingdir, preprocess, usejavac`,...), and does not provide access to the new features of AspectJ 1.1. (Developers using AspectJ 1.1 only should upgrade their scripts to use AjcTask instead.)

### Ajc10 (ajc) Options

Most attributes and nested elements are optional. The compiler requires that the same version of `aspectjrt.jar` be specified on the classpath, and that some sources be be specified (using one or more of `argfiles` and `srcdir` (with patterns)).

Boolean parameters default to `false` unless otherwise stated.

#### AjcTask (ajc) options for specifying sources

Attribute | Description
--- | ---
srcdir | The base directory of the java files. See
destdir | The target directory for the output .class files
includes | Comma-separated list of patterns of files that must be included. No files are included when omitted.
includesfile | The path to a file containing include patterns.
excludes | Comma-separated list of patterns of files that must be excluded. No files (except default excludes) are excluded when omitted.
excludesfile | The path to a file containing exclude patterns.
defaultexcludes | If true, then default excludes are used. Default excludes are used when omitted (i.e., defaults to `true`).
classpath, classpathref | The classpath to use, optionally given as a reference to a classpath Path element defined elsewhere.
bootclasspath, bootclasspathref | The bootclasspath to use, optionally given as a reference to a bootclasspath Path element defined elsewhere.
extdirs | Paths to directories containting installed extensions.
debug | If true, emit debug info in the .class files.
deprecation | If true, emit messages about use of deprecated API.
verbose | Emit compiler status messages during the compile.
version | Emit version information and quit.
failonerror | If true, throw BuildException to halt build if there are any compiler errors. If false, continue notwithstanding compile errors. Defaults to `true`.
source | Value of -source option - ignored unless `1.4`.

#### Parameters ignored by the old ajc taskdef, but now supported or buggy

Attribute | Description | Supported?
--- | --- | ---
encoding | Default encoding of source files. | yes
optimize | Whether source should be compiled with optimization. | yes?
target | Generate class files for specific VM version, one of [`1.1 1.2`]. | yes
depend | Enables dependency-tracking. | no
includeAntRuntime | Whether to include the Ant run-time libraries. | no
includeJavaRuntime | Whether to include the run-time libraries from the executing VM. | no
threads | Multi-threaded compilation | no

The following table shows that many of the unique parameters in AspectJ 1.0 are no longer supported.

#### Parameters unique to ajc

Attribute | Description
--- | ---
X | comma-delimited list of extended (-X...) options, entered without -X (e.g., `X="lint"` for -Xlint).
emacssym | Generate symbols for Emacs IDE support.
argfiles | A comma-delimited list of argfiles that contain a line-delimited list of source file paths (absolute or relative to the argfile).

#### argfiles - argument list files

An argument file is a file (usually `{file}.lst`) containing a list of source file paths (absolute or relative to the argfile). You can use it to specify all source files to be compiled, which ajc requires to avoid searching every possible source file in the source path when building aspects. If you specify an argfile to the ajc task, it will not include all files in any specified source directory (which is the default behavior for the Javac task when no includes are specified). Conversely, if you specify excludes, they will be removed from the list of files compiled even if they were specified in an argument file.

The compiler also accepts arguments that are not source files, but the IDE support for such files varies, and Javac does not support them. Be sure to include exactly one argument on each line.

### Ajc10 parameters specified as nested elements

This task forms an implicit FileSet and supports all attributes of `<fileset>` (dir becomes srcdir) as well as the nested `<include>`, `<exclude>`, and `<patternset>` elements. These can be used to specify source files.

`ajc`'s `srcdir`, `classpath`, `bootclasspath`, `extdirs`, and `jvmarg` attributes are path-like structures and can also be set via nested `<src>`, `<classpath>`, `<bootclasspath>`, `<extdirs>`, and `<jvmargs>` elements, respectively.

### Sample of ajc task

Following is a declaration for the ajc task and a sample invocation that uses the ajc compiler to compile the files listed in `default.lst` into the dest dir:

    <project name="example" default="compile" >
      <taskdef name="ajc"
        classname="org.aspectj.tools.ant.taskdefs.Ajc10" >
        <!-- declare classes needed to run the tasks and tools -->
        <classpath>
          <pathelement location="${home.dir}/tools/aspectj/lib/aspectjtools.jar"/>
        </classpath>
      </taskdef>

      <target name="compile" >
        <mkdir dir="dest" />
        <ajc destdir="dest" argfiles="default.lst" >
          <!-- declare classes needed to compile the target files -->
          <classpath>
            <pathelement location="${home.dir}/tools/aspectj/lib/aspectjrt.jar"/>
          </classpath>
        </ajc>
      </target>
    </project>

This build script snippet

    		  <ajc srcdir="${src}"
    		       destdir="${build}"
    		       argfiles="demo.lst"
    		  />

compiles all .java files specified in the demo.lst and stores the .class files in the ${build} directory. Unlike the Javac task, the includes attribute is empty by default, so only those files specified in demo.lst are included.

This next example

    		  <ajc srcdir="${src}"
    		       destdir="${build}"
    		       includes="spacewar/*,coordination/*"
    		       excludes="spacewar/Debug.java"
    		  />

compiles .java files under the `${src}` directory in the spacewar and coordination packages, and stores the .class files in the `${build}` directory. All source files under spacewar/ and coordination/ are used, except Debug.java.

See ../examples/build.xml for an example build script.

## Isolating problems running the Ant tasks

If you have problems with the tasks not solved by the documentation, please try to see if you have the same problems when running ajc directly on the command line.

- If the problem occurs on the command line also, then the problem is not in the task. (It may be in the tools; please send bug reports.)

- If the problem does not occur on the command line, then it may lie in the parameters you are supplying in Ant or in the task's handling of them.

- If the build script looks correct and the problem only occurs when building from Ant, then please send a report (including your build file, if possible).

### Known issues with the Ant tasks

For the most up-to-date information on known problems, see the bug database for unresolved compiler bugs or taskdef bugs .

When running Ant build scripts under Eclipse 2.x variants, you will get a VerifyError because the Eclipse Ant support fails to isolate the Ant runtime properly. To run in this context, set up iajc to fork (and use forkclasspath). Eclipse 3.0 will fork Ant processes to avoid problems like this.

Memory and forking: Users email most often about the ajc task running out of memory. This is not a problem with the task; some compiles take a lot of memory, often more than similar compiles using javac.

Forking is now supported in both the and , and you can set the maximum memory available. You can also not fork and increase the memory available to Ant (see the Ant documentation, searching for ANT_OPTS, the variable they use in their scripts to pass VM options, e.g., ANT_OPTS=-Xmx128m).

### Ant task questions and bugs

For questions, you can send email to aspectj-users@dev.eclipse.org. (Do join the list to participate!) We also welcome any bug reports, patches, and features; you can submit them to the bug database at http://bugs.eclipse.org/bugs using the AspectJ product and Ant component.