Internal compiler error triggered by constructor argument or @see in javadoc

[theRealAJR]

Given two simple classes which both reside in src/test of a newly created Java project named Compiler Error with default settings:

package test;

public class SuperClass
{
    public SuperClass()
    {
    }

    public SuperClass(byte[] data)
    {
    }
}

package test;

public class SubClass extends SuperClass
{
    /**
     * @see SuperClass#SuperClass()
     */
    public SubClass(int x)
    {
    }
}

Eclipse produces this error:

Internal compiler error: java.lang.RuntimeException: 
   Internal Error compiling /Compiler Error/src/test/SubClass.java 
     at org.eclipse.jdt.internal.compiler.ProcessTaskManager.processing(ProcessTaskManager.java:139)	
     SubClass.java	/Compiler Error/src/test	line 0	Java Problem

The error disappears when:

• The @see javadoc annotation is removed
• @see SuperClass#SuperClass() is changed to @see SuperClassX#SuperClass()
• @see SuperClass#SuperClass() is changed to @see SuperClass#SuperClassX()
• @see SuperClass#SuperClass() is changed to @see SuperClass#SuperClass
• Parameter int x is removed from the SubClass constructor
• Any or all constructors are removed from SuperClass

The problem first occurred with Eclipse version 2025-09 and is still happening in Eclipse version 2025-12. Eclipse 2025-06 did not show the problem.

[srikanth-sankaran]

Jay, thanks for taking a look (if my understanding of Javadoc ownership is incorrect, please reroute. TIA)

[tosspro]

Seems I have the same compiler error in javadoc and link to the constructor:

public class SSLConfig extends SSLParameters {
	/**
	 * Create object with given SSLContext and new {@link SSLParameters#SSLParameters()}.
	 * 
	 * @param sslContext
	 */
	public SSLConfig(SSLContext sslContext) {
		super();
	}
}

Error on the entire file:

Internal compiler error: java.lang.RuntimeException: Internal Error compiling * at 
org.eclipse.jdt.internal.compiler.ProcessTaskManager.processing(ProcessTaskManager.java:139)

Error dissapear only if remove constructor part in the link tag.

Full unprocessing javadocs also suppresses this error:
Preferences - Java - Compiler - Javadoc - uncheck "Process javadoc comments"

[jarthana]

The trouble happens because Javadoc, while trying to get the constructor from the method scope, is passing the parameters from the declaration. This happens in Javadoc, line no 360 with this code:

MethodBinding superConstructor = methScope.getConstructor(superType, methDecl.binding.parameters, allocationExpr);

But the problem is, the method references here is not related, esp. because the argument from the Javadoc don't match. The simplest fix would be to ignore if it the arguments and parameters don't match in size.

I can draw parallel from ExplicitConstructorCall#resolve() where we similarly leave out the ones that don't match in parameters.

I will post a fix shortly.

[jarthana]

Just for the records, here's the actual cause:

java.lang.NullPointerException: Cannot read the array length because "invArgs" is null
at org.eclipse.jdt.internal.compiler.lookup.Scope.parameterCompatibilityLevel(Scope.java:4967)
at org.eclipse.jdt.internal.compiler.lookup.Scope.computeCompatibleMethod(Scope.java:835)
at org.eclipse.jdt.internal.compiler.lookup.Scope.getConstructor0(Scope.java:2453)
at org.eclipse.jdt.internal.compiler.lookup.Scope.getConstructor(Scope.java:2416)
at org.eclipse.jdt.internal.compiler.ast.Javadoc.resolve(Javadoc.java:365)

This is a new code added by #4251.

Expression[] invArgs = invocation.arguments();
int idx = i < invArgs.length ? i : invArgs.length - 1;

The arguments() can return null, but we seem to have taken care to omit the empty cases in all places, except the one I am fixing now.
@stephan-herrmann If you think we could use a null check here, please let me know. I will add it.