I found it, the tricky part was there are so many repos just listed there on their git repo page (http://git.eclipse.org/c/), you kind of have to inspect each page, it is listed under the category "platform", as opposed to all the plugin ID's being listed in alphabetic order:

For org.eclipse.debug.core (where IProcess is), it is here:

http://git.eclipse.org/c/platform/eclipse.platform.debug.git/tree/org.eclipse.debug.core

When you are coding in Eclipse, press CTRL and click on any core Java class name in your source. Eclipse will now show a screen saying you don't have the sources installed. However, in this screen there is a link saying "Attach source...". Click that link and import the src.zip file from your JDK installation directory (src.zip). This should do the trick

In order to see the source codes of JDK in eclipse you should add JDK path instead of JRE to your workspace or for a specific project SDK. I assume you are a developer and you've installed JDK on your system.

To do that:

1. Right click and select Properties (or press Alt+Enter) on your project.
2. From the left tree styled menu select Java Build Path
3. On the right select the Libraries
4. Select the JRE System Library

5. From the right side buttons click on edit, and edit the path from JRE location to points to the JDK location in your file system.

6. Then click on Finish and the OK buttons of all opened dialogs to save the configurations and you set to go.

Hope this would be helpful.

Short answer would be yes.

You can attach source using the properties for a project.

Go to Properties (for the Project) -> Java Build Path -> Libraries

Select the Library you want to attach source/javadoc for and then expand it, you'll see a list like so:

Source Attachment: (none)
Javadoc location: (none)
Native library location: (none)
Access rules: (No restrictions)

Select Javadoc location and then click Edit on the right hahnd side. It should be quite straight forward from there.

First do not use Workbench this is an internal class and must not be used. Use PlatformUI to get the workbench.

IEditorPart editor = PlatformUI.getWorkbench().getActiveWorkbenchWindow().getActivePage().getActiveEditor();

if (editor instanceof ITextEditor)
 {
   ITextEditor textEditor = (ITextEditor)editor;

   IDocumentProvider provider = textEditor.getDocumentProvider();

   IEditorInput input = editor.getEditorInput();

   IDocument document = provider.getDocument(input);

   String text = document.get();

   ...
 }

Note: Not all editors are text editors so this needs to be checked (the ITextEditor instance check above).

The Eclipse SDK ships with Source bundles. These bundles contain the source code used for that version, but you can't really build them to get the IDE. These are shipped so that developers can see / use the source while they're developing their own application.

Depending on what you're trying to do in your research project, these bundles might be enough. For example, if you want to do some analysis techniques or code metrics, you can probably just use these. You can download old SDKs from the archive server.

If this is not enough, and you need to re-create the exact source code that was used for each release, you'll need to clone the Git repositories and checkout the tag associated with Each release. This is going to be complicated since there are about 22 different source repos for the IDE alone. Here is a link to the list of repos.