[GR-66205] Native images don't print "Helpful NullPointerExceptions" (JEP 358)

[zakkak]

Describe the issue
JVM prints:

Exception in thread "main" java.lang.NullPointerException: Cannot invoke "String.length()" because "HelloWorld.name" is null
	at HelloWorld.main(HelloWorld.java:6)

while the corresponding native image prints:

Exception in thread "main" java.lang.NullPointerException
	at HelloWorld.main(HelloWorld.java:6)

Steps to reproduce the issue

cat > HelloWorld.java <<EOF                                                                                                                                                                     
public class HelloWorld {

    static final String name = null;

    public static void main(String[] args) {
        System.out.println("Hello world! " + name.length());
    }

}
EOF
javac HelloWorld.java
java HelloWorld
native-image -cp ./ HelloWorld
./helloworld

Describe GraalVM and your environment:

• GraalVM version (latest snapshot builds can be found here), or commit id if built from source: a5ce3a7
• JDK major version: 24+3
• OS: Fedora 40
• Architecture: AMD64

More details
Originally reported in quarkusio/quarkus#43274

[zakkak]

FWIW in order to "fix" this, substratevm should implement

graal/substratevm/src/com.oracle.svm.core/src/com/oracle/svm/core/jdk/JavaLangSubstitutions.java

Lines 607 to 611 in bd969aa

	@Substitute
	@SuppressWarnings("static-method")
	private String getExtendedNPEMessage() {
	return null;
	}

[zapster]

Hey @zakkak! Back when this feature was added to the JDK, we consciously decided against supporting it. Implementing it would require a lot of metadata (comparable to full deoptimization infos required for run-time compilation in native image), which would grow the image size significantly. Since it is only a quality-of-life feature, we don't plan on adding support. That said, we are open for external contributions of someone really wants this feature, as long as it is optional and has no impact on the default image size and maintainability of the code base.

[zakkak]

Thanks for the clarification @zapster