Checking inputs before running dependent tasks - ant

I've got a Ant build script which I need to compile part of my project (it links into a third-party build system for the JavaScript libraries we use).
I want to wrap Gradle around this, so I've imported the Ant build, and I can successfully invoke the Ant targets via Gradle. I've even added input and output checking to the targets, so that they won't run if they don't need to
The Ant targets have setup work that they do - mostly importing configurations and settings. They do this via a dependency on an init target, which takes about 4-5 seconds to run. What I would like to do is prevent that init target running if the inputs on the main task have been satisfied.
Any suggestions?
Example Ant build script (build.xml):
<?xml version="1.0" encoding="utf-8"?>
<project name="MyProject" default="build">
<target name="init" />
<target name="build" depends="init">
<echo message="hello" file="output.txt" />
</target>
</project>
Example Gradle script to go with it (build.gradle):
ant.importBuild 'build.xml'
build {
inputs.dir file('src')
outputs.file file('output.txt')
}
Ideally, when I run gradle build, I don't want init to run if build is up-to-date.
Any suggestions?

The up-to-date check for build will only happen after init has run. What you can do is to declare the same inputs for init, and if it has no file outputs, outputs.upToDateWhen { true }. Perhaps this meets your needs.

Related

Jenkins AntExec plugin not working with ant contrib

I have latest Jenkins running on Windows 2003 server.
Under, manage Jenkins:
I have IBM JDK set
I have ant: org.apache.ant_1.7.1.v20100518-1145 set as ant home
I have Jenkins AntExec plug in installed.
I have ant-contrib-0.6.jar inside anthome/lib.
I created a job, and added a build step, Execute Apache Ant, and I have this:
<echo> java home = ${JAVA_HOME}</echo>
<taskdef resource="net/sf/antcontrib/antlib.xml"/>
<project name="Test">
<description> Sample bulid file </description>
<target name="first">
<echo message="The first five letters of the alphabet are:"/>
<antcontrib:for list="a,b,c,d,e" param="letter">
<sequential>
<echo>Letter #{letter}</echo>
</sequential>
</antcontrib:for>
</target>
</project>
when I run build, it fails.
antexec_build.xml:
[echo] ant home = ${ANT_HOME}
[echo] java home = ${JAVA_HOME}
BUILD FAILED
C:\Program Files (x86)\Jenkins\jobs\MCSOWelcome\workspace\antexec_build.xml:13: Problem: failed to create task or type project
Cause: The name is undefined.
Action: Check the spelling.
Action: Check that any custom tasks/types have been declared.
Action: Check that any <presetdef>/<macrodef> declarations have taken place.
I have tried many different things, no luck. Please suggest
AntExec comes bundled with AntContrib. You do not need to add or define it. On the contrary, to disable it, you need to open 2 Advanced... dialogs before you get the option.
What you need to do though, is use antcontrib namespace.
For example, to use for, type:
<antcontrib:for>
I ran into the same problem (I got the same error message: Problem: failed to create task or type project), although I didn't use <antcontrib:for> tag.
If you type some code to the Script source field at the Project configuration > Execute Apache Ant, the plugin doesn't use it as an entire Ant script file, but it inserts into a template script. It appears if you choose to keep the buildfile (Advanced view at Execute Ant Build step). In this case the generated antexec_build.xml Ant script will not be deleted from the Workspace of the Project after the build.
The issue is reproducable with this simple script typed in Script source:
<project>
</project>
The generated antexec_build.xml:
<?xml version="1.0" encoding="utf-8"?>
<project default="antexec_build.xml" xmlns:antcontrib="antlib:net.sf.antcontrib" basedir=".">
<!-- Read additional properties -->
<property file="antexec_build.xml.properties"/>
<!-- Make environment variables accesible via ${env.VARIABLE} by default -->
<property environment="env"/>
<target name="antexec_build.xml">
<!-- Default target entered in the first textarea - begin -->
<project>
</project>
<!-- Default target entered in the first textarea - end -->
</target>
</project>
So that, a solution would be that only include the Ant script that you intend to insert into the <target></target> tag.

Using "antcall" in included ant files

I have a shared ant script b.ant which internally use antcall. It calculates a property that the client scripts use. I use include instead of import client scripts to avoid unintentional overwriting of targets, but this gives me a problem with the antcall.
When using include all targets in b are prefixes, and depends attributes in b are updated accordingly. This is however not true for antcall. Is there a there are way to handle this, i.e. make antcall always call the "local" ant target?
I can workaround this by using import, but then I'll get all the overwrite problems. It is not possible to use depends instead of antcall.
Example files
I have two files:
a.ant
<project>
<include file="b.ant" as="b" />
<target name="test-depends" depends="b.depend">
<echo>${calculated-property}</echo>
</target>
<target name="test-call" depends="b.call">
<echo>${calculated-property}</echo>
</target>
</project>
b.ant
<project>
<target name="depend" depends="some-target">
<property name="calculated-property" value="Hello World"/>
</target>
<target name="call">
<antcall target="some-target" inheritrefs="true"/>
<property name="calculated-property" value="Hello World"/>
</target>
<target name="some-target"/>
</project>
Example output
Calling test-depend works as expected but test-call fails with this output:
b.call:
BUILD FAILED
D:\ws\rambo2\ws-dobshl\ant-test\b.ant:6: The following error occurred while executing this line:
Target "some-target" does not exist in the project "null".
Total time: 258 milliseconds
Ant is a dependency matrix specification language. Usually a bunch of <antcall/>, <ant/>, <include/> and <import/> is a sign of a poorly written build script. It's a developer trying to force Ant to act like a programming language.
For developer, it makes sense to break up a program into smaller files. Even Python and Perl scripts can benefit from this. However, breaking up an Ant build script usually causes problems. We had a developer who went through every project and broke up all the build.xml files into six or seven separate build files in order to improve the process. It basically broke the whole Ant dependency mechanism. To fix it, he then tossed in a bunch of <ant/> calls and <include> tasks. In the end, it meant that each target was called between 12 to 20 times.
Not using <import/> and <antcall/> isn't a hard and fast rule. But, I've been using Ant for years and rarely ever used these mechanisms. When I do, it's usually for a shared build file that multiple projects will use (which sounds like what you have) but instead of defining targets in my shared build file, I define macros. This eliminates the target namespace issues that you are having, and the macros work better because they act more like Ant tasks. This is especially true with the introduction of <local/> in Ant 1.8.
See if you can restructure the shared build file into using <macrodef/> instead of targets. It will make it much easier to include your shared build file.
Give a name to the <project> in b.ant and then change the target of the <antcall>:
<project name="b"> <!-- Give the project a name -->
<target name="depend" depends="some-target">
<property name="calculated-property" value="In b.depend"/>
</target>
<target name="call">
<!-- Specify the name of the project containing the target -->
<antcall target="b.some-target" inheritrefs="true"/>
<property name="calculated-property" value="In b.call"/>
</target>
<target name="some-target"/>
</project>
The result of ant -f a.ant test-call:
b.call:
b.some-target:
test-call:
[echo] In b.call
BUILD SUCCESSFUL
With the changes to b.ant, the <include> in a.ant can be simplified by removing the as attribute:
<include file="b.ant" />

Dependent targets executed twice if two targets in command line

I have an Ant build file with dependencies as follow:
<target name="resolve">
....
</target>
<target name="compile" depends="resolve">
....
</target>
<target name="ship" depends="compile">
....
</target>
When invoking only the ship target with ant ship, only needed target are executed in the right order: [resolve>compile>ship].
The issue is when directly invoking two targets on the command line.
By executing ant compile ship, the output is [resolve > compile > resolve > compile > ship]. I cannot understand the logic chosen to execute some dependencies twice.
How can I force Ant to never execute a target twice ? With a very complex build file, I cannot always run the intended command with a single target.

Ant: "Duplicated project name in import" with imported build file

I have several build files which all import the same base build file, like this:
base.xml:
<project name="base">
<!-- does not define a 'build' target -->
</project>
buildA.xml:
<project name="buildA">
<import file="base.xml" />
<target name="build">
<ant antfile="buildB.xml" target="build"
inheritall="false" inheritrefs="false" />
</target>
</project>
buildB.xml:
<project name="buildB">
<import file="base.xml" />
<target name="build">
...snip...
</target>
</project>
(Module A depends on module B.)
Now, the above calling of B's build target from buildA.xml gives the following error:
Duplicated project name in import. Project base defined first in buildA.xml and again in buildB.xml
Since both buildA.xml and buildB.xml inherit the same base.xml, this seems unavoidable.
How could I get rid of this error?
Based on sudocode's answer, I solved the problem. Because the absolute path to base.xml is different in both cases, Ant does not recognize it as the same file. Even though inheritAll is set to false, the context of the calling task is preserved and this causes the name clash.
To solve this, one can omit the name attribute from base.xml. Since Ant 1.8, the import task has an attribute as, which can be used to reference base targets when the base project is nameless. If you don't override any targets, you can use include instead of import. I'm on 1.7, so that does not help me.
For previous versions of Ant, you can go through an exec call to prevent proliferation of the Ant context entirely (then you get two running Ant instances). Better yet, find a way to import the exact same base.xml (with the same absolute path) in both files.
Are you using Ant 1.6? This resolved Ant bug looks like the same issue.
EDIT
I tried to reproduce the dir structure you refer to in your recent comment.
./base.xml
./buildA
./buildA/buildA.xml
./buildB
./buildB/buildB.xml
And amended the build files accordingly, e.g.
<project name="buildA">
<import file="../base.xml"/>
<target name="build">
<ant antfile="../buildB/buildB.xml" target="build" inheritall="false" inheritrefs="false"/>
</target>
</project>
I still get no build error for the following with ant 1.8.2 or 1.7.1:
ant -f buildA/buildA.xml build

How to solve "Cause: the class org.apache.tools.ant.taskdefs.optional.junit.JUnitTask was not found." while running "ant test"?

I have a target named test and I want to do some tests.
I put here the important parts in build.xml. It includes:
<property name='lib.dir' value='lib' />
<path id='classpath'>
<fileset dir="${lib.dir}" includes="**/*.jar" />
</path>
And I have put the junit.jar and ant-junit.jar(is it a must?) in the lib directory.
However, if I run
ant test.
The output error is:
test:
BUILD FAILED
/home/xiaohan/EclipseWorkSpace/AntTest/build.xml:82: Problem: failed to create task or type junit
Cause: the class org.apache.tools.ant.taskdefs.optional.junit.JUnitTask was not found.
This looks like one of Ant's optional components.
Action: Check that the appropriate optional JAR exists in
-/usr/share/ant/lib
-/home/xiaohan/.ant/lib
-a directory added on the command line with the -lib argument
Do not panic, this is a common problem.
The commonest cause is a missing JAR.
This is not a bug; it is a configuration problem
Additionally, if I put the two jar files in /usr/share/ant/lib with the $ANT_HOME set, it still does not work.
Really thanks for any hints
In my case (using Mint, based on Debian)
sudo apt-get install ant-optional
was the only thing that worked.
The issue was solved on RHEL-based systems once ant-junit was installed:
$ sudo yum install ant-junit
<property name='lib.dir' value='lib' />
<path id='classpath'>
<fileset dir="${lib.dir}" includes="**/*.jar" />
</path>
this has nothing to do with Ant classpath itself. It is properties you can use in your tasks. You have to put jars to the suggested dirs or add command line argument.
Try running it like this:
ant -lib /path/to/the/ant-junit.jar/ test
I was seeing this message because I had missed to include the ant-junit.jar from my IDE's Classpath, e.g. in Eclipse > Right click on your project > Run as > Run Configurations.. > Classpath (tab) > Ensure the ant-junit.jar is there.
When you run JUnit tasks, you must make sure both your classpath that was used for your builds, and the path for the junit jars are added to your classpath.
I prefer to put the junit jars inside my project, so others don't have to install them in their machines for my build to work. I would install them in ${basedir}/antlib/junit
I use ${basedir}/antlib to store all the various Ant build related jars such as the Ant-Contrib jars, JaCoCo, Findbugs, etc. Since this is inside my project, a checkout will always include these jars and the build will work for everyone:
<classpath id="junit.path">
<fileset dir="${basedir}/antlib/junit"/>
</classpath>
This will create a path that contains your JUnit jars. Now to compile your junit tests:
<javac dest="${target.dir}/test-classes"
src=${src.test.java}">
<classpath refid="javac.classpath"/> <!-- Your main build classpath -->
<classpath refid="junit.path"/> <!-- Your JUnit classpath -->
<classpath path="${main.destdir}"/> <!-- These the classes you've built-->
Note that placing the JUnit jars in $ANT_HOME/lib main not work because it depends whether <javac> has includeAntRuntime set or not. It's always highly recommended not to have this set in order to make your build more platform independent.
Also remember to include that junit.path in your <junit> task too.

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