Update dependencies to Eclipse 2025-12, replace obsolete target files

[travkin79]

As requested by @jdneo, I prepared a new target platform definition for Eclipse 2025-12 (Eclipse 4.38).

This PR

• adds new targets 2025-12.target (for Eclipse 4.38 and later), 2024-12.target for terminal.tm bundle and Eclipse 4.36 and earlier
• replaces the obsolete target files in Maven build
• updates documentation
• replaces JDK 17 with JDK 21 (since Eclipse 2025-12 requires JDK 21)
• adds a Maven (m2e) launch config for mvn clean verify
• sets projects' encoding to UTF-8
• unifies output folders to target/classes
• fixes a compile error in Eclipse, avoids "OSGi access rules not enforced by classpath access rules, which can lead to classloading errors at runtime." error message

[Copilot]

Pull request overview

Updates the GitHub Copilot for Eclipse build and development setup to target Eclipse 2025-12 (Eclipse 4.38) and Java 21, while removing legacy/obsolete target definitions and the legacy TM-terminal bundle intended for older Eclipse versions.

Changes:

• Introduces a new target definition for Eclipse 2025-12 and updates Tycho/Maven to build against it.
• Migrates bundle execution environments and Eclipse project settings from Java 17 to Java 21; standardizes encodings/output folders.
• Removes obsolete target files and deletes the legacy com.microsoft.copilot.eclipse.ui.terminal.tm bundle.

Reviewed changes

Copilot reviewed 66 out of 66 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
target-tm-terminal.target	Removed obsolete TM-terminal target definition.
target-terminal.target	Removed obsolete terminal target definition.
target-platforms/2025-12.target	Added new Eclipse 2025-12 target platform definition (incl. Orbit deps).
pom.xml	Drops legacy TM-terminal module and points Tycho at the new 2025-12 target + JavaSE-21.
launch/Verify Copilot for Eclipse.launch	Adds an m2e launch config for mvn clean verify.
launch/plugin_debug_configuration.launch	Updates PDE launch JRE from Java 17 to Java 21.
CONTRIBUTING.md	Updates dev prerequisites and target-platform guidance to 2025-12 / Java 21.
com.microsoft.copilot.eclipse.ui/META-INF/MANIFEST.MF	Bumps BREE to JavaSE-21.
com.microsoft.copilot.eclipse.ui/build.properties	Normalizes source/output folder entries.
com.microsoft.copilot.eclipse.ui/.settings/org.eclipse.jdt.core.prefs	Updates compiler settings to Java 21.
com.microsoft.copilot.eclipse.ui/.settings/org.eclipse.core.resources.prefs	Sets project encoding to UTF-8.
com.microsoft.copilot.eclipse.ui/.classpath	Updates JRE container to JavaSE-21 and marks it as modular.
com.microsoft.copilot.eclipse.ui.test/META-INF/MANIFEST.MF	Bumps BREE to JavaSE-21.
com.microsoft.copilot.eclipse.ui.test/build.properties	Normalizes source/output folder entries.
com.microsoft.copilot.eclipse.ui.test/.settings/org.eclipse.jdt.core.prefs	Updates compiler settings to Java 21.
com.microsoft.copilot.eclipse.ui.test/.settings/org.eclipse.core.resources.prefs	Sets project encoding to UTF-8.
com.microsoft.copilot.eclipse.ui.test/.classpath	Updates JRE container to JavaSE-21 and marks it as modular.
com.microsoft.copilot.eclipse.ui.terminal/pom.xml	Switches Tycho target file to the new 2025-12 target.
com.microsoft.copilot.eclipse.ui.terminal/META-INF/MANIFEST.MF	Bumps BREE to JavaSE-21.
com.microsoft.copilot.eclipse.ui.terminal/build.properties	Unifies output folder to target/classes/.
com.microsoft.copilot.eclipse.ui.terminal/.settings/org.eclipse.jdt.core.prefs	Updates compiler settings to Java 21.
com.microsoft.copilot.eclipse.ui.terminal/.settings/org.eclipse.core.resources.prefs	Sets project encoding to UTF-8.
com.microsoft.copilot.eclipse.ui.terminal/.classpath	Updates JRE container to JavaSE-21 and marks it as modular.
com.microsoft.copilot.eclipse.ui.terminal.tm/src/com/microsoft/copilot/eclipse/ui/terminal/tm/RunInTerminalTool.java	Removes legacy TM-terminal implementation.
com.microsoft.copilot.eclipse.ui.terminal.tm/pom.xml	Removes legacy bundle’s Maven module definition.
com.microsoft.copilot.eclipse.ui.terminal.tm/OSGI-INF/component.xml	Removes DS component definition for legacy bundle.
com.microsoft.copilot.eclipse.ui.terminal.tm/META-INF/MANIFEST.MF	Removes OSGi manifest for legacy bundle.
com.microsoft.copilot.eclipse.ui.terminal.tm/build.properties	Removes PDE build properties for legacy bundle.
com.microsoft.copilot.eclipse.ui.terminal.tm/.settings/org.eclipse.m2e.core.prefs	Removes legacy module m2e settings.
com.microsoft.copilot.eclipse.ui.terminal.tm/.settings/org.eclipse.jdt.core.prefs	Removes legacy module Java compiler settings.
com.microsoft.copilot.eclipse.ui.terminal.tm/.project	Removes legacy Eclipse project metadata.
com.microsoft.copilot.eclipse.ui.terminal.tm/.classpath	Removes legacy module classpath metadata.
com.microsoft.copilot.eclipse.ui.terminal.tm/.checkstyle	Removes legacy module Checkstyle metadata.
com.microsoft.copilot.eclipse.ui.jobs/META-INF/MANIFEST.MF	Bumps BREE to JavaSE-21.
com.microsoft.copilot.eclipse.ui.jobs/build.properties	Unifies output folder to target/classes/.
com.microsoft.copilot.eclipse.ui.jobs/.settings/org.eclipse.jdt.core.prefs	Updates compiler settings to Java 21 (and forbiddenReference severity).
com.microsoft.copilot.eclipse.ui.jobs/.settings/org.eclipse.core.resources.prefs	Sets project encoding to UTF-8.
com.microsoft.copilot.eclipse.ui.jobs/.classpath	Updates JRE container to JavaSE-21 and marks it as modular.
com.microsoft.copilot.eclipse.terminal.api/META-INF/MANIFEST.MF	Bumps BREE to JavaSE-21.
com.microsoft.copilot.eclipse.terminal.api/build.properties	Unifies output folder to target/classes/.
com.microsoft.copilot.eclipse.terminal.api/.settings/org.eclipse.jdt.core.prefs	Updates compiler settings to Java 21.
com.microsoft.copilot.eclipse.terminal.api/.settings/org.eclipse.core.resources.prefs	Sets project encoding to UTF-8.
com.microsoft.copilot.eclipse.terminal.api/.classpath	Updates JRE container to JavaSE-21 and marks it as modular.
com.microsoft.copilot.eclipse.swtbot.test/META-INF/MANIFEST.MF	Bumps BREE to JavaSE-21.
com.microsoft.copilot.eclipse.swtbot.test/build.properties	Normalizes source/output folder entries.
com.microsoft.copilot.eclipse.swtbot.test/.settings/org.eclipse.jdt.core.prefs	Updates compiler settings to Java 21.
com.microsoft.copilot.eclipse.swtbot.test/.settings/org.eclipse.core.resources.prefs	Sets project encoding to UTF-8.
com.microsoft.copilot.eclipse.swtbot.test/.classpath	Updates JRE container to JavaSE-21 and marks it as modular.
com.microsoft.copilot.eclipse.core/META-INF/MANIFEST.MF	Bumps BREE to JavaSE-21 (and touches exported package metadata).
com.microsoft.copilot.eclipse.core/build.properties	Normalizes source/output folder entries.
com.microsoft.copilot.eclipse.core/.settings/org.eclipse.jdt.core.prefs	Updates compiler settings to Java 21 and related codegen/debug prefs.
com.microsoft.copilot.eclipse.core/.settings/org.eclipse.core.resources.prefs	Sets project encoding to UTF-8.
com.microsoft.copilot.eclipse.core/.classpath	Updates JRE container to JavaSE-21 and marks it as modular.
com.microsoft.copilot.eclipse.core.test/META-INF/MANIFEST.MF	Bumps BREE to JavaSE-21.
com.microsoft.copilot.eclipse.core.test/build.properties	Normalizes source/output folder entries.
com.microsoft.copilot.eclipse.core.test/.settings/org.eclipse.jdt.core.prefs	Updates compiler settings to Java 21.
com.microsoft.copilot.eclipse.core.test/.settings/org.eclipse.core.resources.prefs	Sets project encoding to UTF-8.
com.microsoft.copilot.eclipse.core.test/.classpath	Updates JRE container to JavaSE-21 and marks it as modular.
com.microsoft.copilot.eclipse.core.agent.win32/META-INF/MANIFEST.MF	Bumps fragment BREE to JavaSE-21.
com.microsoft.copilot.eclipse.core.agent.macosx.x64/META-INF/MANIFEST.MF	Bumps fragment BREE to JavaSE-21.
com.microsoft.copilot.eclipse.core.agent.macosx.aarch64/META-INF/MANIFEST.MF	Bumps fragment BREE to JavaSE-21.
com.microsoft.copilot.eclipse.core.agent.linux.x64/META-INF/MANIFEST.MF	Bumps fragment BREE to JavaSE-21.
com.microsoft.copilot.eclipse.core.agent.linux.aarch64/META-INF/MANIFEST.MF	Bumps fragment BREE to JavaSE-21.
base.target	Removes the previous base target definition.
.github/workflows/ci.yml	Updates CI to use JDK 21.
.github/copilot-instructions.md	Updates repo instructions to reference the new target + Java 21 baseline.

[travkin79]

Fixed

[travkin79]

Change undone

[travkin79]

I see, we also need to remove the obsolete dynamic loading of the terminal bundles. I'll continue with that tomorrow.

[jdneo]

Wait, is removing the tm bundle a required step for this task?

[iloveeclipse]

Wait, is removing the tm bundle a required step for this task?

Why is this a problem? Of course one can try to use old tm. terminal bundles with "modern" 4.38 Eclipse (I believe it would still work, but I didn't tried it), but what is the point doing so? Benefit is that we finally can get all the dependencies explicitly defined before installation, so the "modern" terminal bundles can be automatically installed along the Copilot plugin, and we don't need to have extra p2 code in Copilot which tries to installs the "right" terminal fragment on second startup.

[travkin79]

Wait, is removing the tm bundle a required step for this task?

Hello @jdneo,
Short answer: No, removing the tm bundle is not a required step.

I thought, the terminal.tm bundle was only needed because of copilot's support for Eclipse versions below 4.37. If we move to the oldest supported Eclipse version 4.38 (2025-12), we no longer need that. So we can (don't have to) remove that obsolete bundle and also the complex terminal bundle loading mechanics that are no longer needed. That would make the code significantly less complex and even the target definition file does no longer need to be splitten into a common base.target plus two different target files for the different terminal bundles. The plug-in dependencies would become obvious and would simplify installation processes. Thus, I fully agree with @iloveeclipse.

I could also separate introducing the new target from removing the tm bundle in two different PRs if you like.

[jdneo]

I tend to avoid removing the tm bundle at current stage, if it is not necessary.

There still quite a lot users using eclipse lower than 4.38, if we remove the tm bundle support, they will lose all the updates and fixes.

[travkin79]

I tend to avoid removing the tm bundle at current stage, if it is not necessary.

There still quite a lot users using eclipse lower than 4.38, if we remove the tm bundle support, they will lose all the updates and fixes.

Hi @jdneo,
I adapted this PR accordingly.

In case you're interested in seeing how removing terminal.tm bundle and obsolete code for dynamically loading the terminal bundles would look like take a look at this branch: https://github.com/travkin79/copilot-for-eclipse/tree/drop-tm-bundle.

In this PR, terminal.tm bundle is built using 2024-12.target, but it seems, all tests (including those running in CI) are using 2025-12.target (similar to using target-terminal.target in main branch). If you want to explicitly test with multiple targets, you might want to adopt the multi-target approach from TM4E project.

[iloveeclipse]

There still quite a lot users using eclipse lower than 4.38

Hmm. If 4.38 is in the target, how do you want to check compatibility with older releases? This would imply extra tests with older target platforms covering all used Eclipse API's are compatible with older versions.

Anyway, would it be easier to only require new versions of lsp4j/lsp4e, because AFAIK they can be changed/installed (almost) independently on used Eclipse SDK version.