I need to set up an Eclipse project with an additional builder that enhances the Java bytecode produced by an earlier builder (ideally Eclipse's own). I managed to get this builder to run and enhance the Eclipse Java builder output properly but seconds later Eclipse re-runs its Java builder and resets the bytecode back. It does not rerun my enhancement builder.
My setup
Alternatives I tried
Try to remove the Java Builder using the following bit in Gradle script (didn't work - it comes back on its own):
eclipse {
project {
file {
whenMerged { projectFile ->
projectFile.buildCommands.removeAll { it.name == 'org.eclipse.jdt.core.javabuilder' }
}
}
}
}
Tried disabling the Java builder manually and have my bytecode enhancement builder also build the files itself (using Gradle). This stores the following file org.eclipse.jdt.core.javabuilder.launch file with the following content ... but upon restart the builder is re-enabled:
<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<launchConfiguration type="org.eclipse.ant.AntBuilderLaunchConfigurationType">
<booleanAttribute key="org.eclipse.ui.externaltools.ATTR_BUILDER_ENABLED" value="false"/>
<stringAttribute key="org.eclipse.ui.externaltools.ATTR_DISABLED_BUILDER" value="org.eclipse.jdt.core.javabuilder"/>
<mapAttribute key="org.eclipse.ui.externaltools.ATTR_TOOL_ARGUMENTS"/>
<booleanAttribute key="org.eclipse.ui.externaltools.ATTR_TRIGGERS_CONFIGURED" value="true"/>
</launchConfiguration>
I tried (and failed) to find if there is some workspace file (as opposed to project file) being changed (as well) to disable the Java builder.
Questions
Can anyone help? Thanks!
UPDATE Additional details I added 12 builders and made them all append output to the same log file to research. The 12 extra builders are just informational - 4 before the Java Builder, 4 between the Java and the enhancement builder and 4 after the enhancement builder. Each of the 12 run in only one of the four conditions (hence 3x4). They are arranged as follows:
Each of the 12 informational builders writes time, its name and the size of a chosen test class. Unenhanced it is 46243 bytes long. When enhanced it becomes 53338 bytes long.
Here's the log after running "Clean" on this project alone ("Build automatically" is enabled):
20:19:19
1d-during-clean
-rw-r--r-- 1 Learner ...\... 46243 3 Mar 20:10 Test.class
20:19:19
2d-during-clean
-rw-r--r-- 1 Learner ...\... 46243 3 Mar 20:10 Test.class
20:19:20
1c-auto
-rw-r--r-- 1 Learner ...\... 46243 3 Mar 20:10 Test.class
20:19:27
2c-auto
-rw-r--r-- 1 Learner ...\... 46243 3 Mar 20:19 Test.class
Buildfile: /.../some-ant.xml
run-gradle:
[echo] Running Gradle: --parallel :...:enhanceEclipseBytecode
...
[java] > Task :...:enhanceBytecode
[java] Enhanced class: ...Test in ...
...
[java] Enhanced 205 classes.
[java] > Task :...:enhanceEclipseBytecode
[java] BUILD SUCCESSFUL in 15s
[java] 2 actionable tasks: 2 executed
BUILD SUCCESSFUL
Total time: 15 seconds
20:19:44
1c-auto
-rw-r--r-- 1 Learner ...\... 53338 3 Mar 20:19 Test.class
20:19:46
1c-auto
-rw-r--r-- 1 Learner ...\... 46243 3 Mar 20:19 Test.class
20:19:46
2c-auto
-rw-r--r-- 1 Learner ...\... 46243 3 Mar 20:19 Test.class
20:19:46
3b-manual
-rw-r--r-- 1 Learner ...\... 46243 3 Mar 20:19 Test.class
20:19:46
3c-auto
-rw-r--r-- 1 Learner ...\... 46243 3 Mar 20:19 Test.class
20:19:46
3d-during-clean
-rw-r--r-- 1 Learner ...\... 46243 3 Mar 20:19 Test.class
20:19:57
1c-auto
-rw-r--r-- 1 Learner ...\... 46243 3 Mar 20:19 Test.class
20:19:57
2c-auto
-rw-r--r-- 1 Learner ...\... 46243 3 Mar 20:19 Test.class
20:19:57
3b-manual
-rw-r--r-- 1 Learner ...\... 46243 3 Mar 20:19 Test.class
20:19:57
3c-auto
-rw-r--r-- 1 Learner ...\... 46243 3 Mar 20:19 Test.class
20:19:57
3d-during-clean
-rw-r--r-- 1 Learner ...\... 46243 3 Mar 20:19 Test.class
UPDATE 2: Minimum example to reproduce
In that folder create build.grade file with the following content:
buildscript {
repositories {
mavenCentral()
}
dependencies {
classpath 'org.hibernate:hibernate-gradle-plugin:5.4.2.Final'
}
}
plugins {
id 'java'
id 'eclipse'
}
apply plugin: 'org.hibernate.orm'
repositories {
mavenCentral()
}
dependencies {
implementation 'org.hibernate.javax.persistence:hibernate-jpa-2.1-api:1.0.0.Final'
}
hibernate {
sourceSets = [ project.sourceSets.main ]
enhance {
enableLazyInitialization = true;
enableDirtyTracking = true;
enableAssociationManagement = false;
enableExtendedEnhancement = false;
}
}
Create a src/main/java/learner/TestEntity.java in there too as follows:
package learner;
import javax.persistence.*;
@Entity
public class TestEntity {
@Id
@Column(name = "id", nullable = false, updatable = false)
private Long id = null;
@Column(name = "name", columnDefinition = "TEXT")
private String name = null;
public Long getId() {
return id;
}
public void setId(final Long id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(final String name) {
this.name = name;
}
}
Execute gradle compileJava. Open the resulting build/classes/java/main/learner/TestEntity.class binary in an ASCII or hex viewer and observe stuff like $$_hibernate_write_name in there.
bin/main/learner/TestEntity.class and observe none of that.There were a few things I was unclear/wrong about and couldn't find relevant documentation to learn the details. Here's a summary of what needs to be known to get this right (some of which I got right from the get go, but not everything):
full and Auto and Manual builds are called auto and incremental. This means that en enhancement builder has to be set to run on After a "Clean" in addition to Auto Build and Manual Build and should NOT be set to run on *During a "Clean". My mistake was to only set it to run for Auto and Manual builds.build.gradle (containing the enhancer). Since these do not change on most builds, Eclipse chooses not to run the builder. The now obvious 20-20 vision truth is that relevant resources for this builder are the Java builder's output binaries (and build.gradle), not the Java source code. However, this isn' the entirely correct choice (in isolation) either as Eclipse, in our case, ends up in an infinite loop - it thinks that the enhancer changed the binaries and, as it is set to run when binaries changed, runs the build again. We cannot NOT set the relevant resources at all as that seems to mean "everything/anything". The enhancer must be made in such a way to NOT even touch the files that are already enhanced [UPDATE] and that isn't enough. Read on.I still don't definitively know why the informational builders I used to research this have their output appended to the common log file in order that isn't chronological. I can only assume that this has to do with Eclipse's output buffering and periodic writing to these files somehow.
[UPDATE 1]
*.class files are NOT deleted and recreated but rewritten and (b) that their last modified time is changed back to what it was before the enhancement. This seems to trick the Eclipse's modification detection enough to break out of the loop even though the file sizes are different. This is with Eclipse 2019-12 (4.14.0.v20191210-0610) and it may stop working with any update. I hope they fix the infinite build loop defect by then.