[Switch Expression] NPE in StackMapFrameCodeStream.recordExpressionType

[rfcom]

java.lang.NullPointerException: Cannot read field "id" because "typeBinding" is null
	at org.eclipse.jdt.internal.compiler.codegen.StackMapFrameCodeStream.recordExpressionType(StackMapFrameCodeStream.java:175)
	at org.eclipse.jdt.internal.compiler.ast.SwitchStatement.generateCode(SwitchStatement.java:933)
	at org.eclipse.jdt.internal.compiler.ast.SwitchExpression.generateCode(SwitchExpression.java:331)
	at org.eclipse.jdt.internal.compiler.ast.Statement.generateArguments(Statement.java:443)
	at org.eclipse.jdt.internal.compiler.ast.AllocationExpression.generateCode(AllocationExpression.java:217)
	at org.eclipse.jdt.internal.compiler.ast.ReturnStatement.generateCode(ReturnStatement.java:214)
	at org.eclipse.jdt.internal.compiler.ast.AbstractMethodDeclaration.generateCode(AbstractMethodDeclaration.java:358)
	at org.eclipse.jdt.internal.compiler.ast.AbstractMethodDeclaration.generateCode(AbstractMethodDeclaration.java:292)
	at org.eclipse.jdt.internal.compiler.ast.TypeDeclaration.generateCode(TypeDeclaration.java:759)
	at org.eclipse.jdt.internal.compiler.ast.TypeDeclaration.generateCode(TypeDeclaration.java:803)
	at org.eclipse.jdt.internal.compiler.ast.QualifiedAllocationExpression.generateCode(QualifiedAllocationExpression.java:250)
	at org.eclipse.jdt.internal.compiler.ast.ReturnStatement.generateCode(ReturnStatement.java:214)
	at org.eclipse.jdt.internal.compiler.ast.AbstractMethodDeclaration.generateCode(AbstractMethodDeclaration.java:358)
	at org.eclipse.jdt.internal.compiler.ast.AbstractMethodDeclaration.generateCode(AbstractMethodDeclaration.java:292)
	at org.eclipse.jdt.internal.compiler.ast.TypeDeclaration.generateCode(TypeDeclaration.java:759)
	at org.eclipse.jdt.internal.compiler.ast.TypeDeclaration.generateCode(TypeDeclaration.java:829)
	at org.eclipse.jdt.internal.compiler.ast.CompilationUnitDeclaration.generateCode(CompilationUnitDeclaration.java:414)
	at org.eclipse.jdt.internal.compiler.Compiler.process(Compiler.java:915)
	at org.eclipse.jdt.internal.compiler.ProcessTaskManager.run(ProcessTaskManager.java:145)
	at java.base/java.lang.Thread.run(Thread.java:833)

https://git.eclipse.org/r/plugins/gitiles/jdt/eclipse.jdt.core/+/master/org.eclipse.jdt.core/compiler/org/eclipse/jdt/internal/compiler/codegen/StackMapFrameCodeStream.java

	@Override
	public void recordExpressionType(TypeBinding typeBinding, int delta, boolean adjustStackDepth) {
		if (adjustStackDepth) {
			// optimized goto
			// the break label already adjusted the stack depth (-1 or -2 depending on the return type)
			// we need to adjust back to what it was
			switch (typeBinding.id) {
				case TypeIds.T_long:
				case TypeIds.T_double:
					this.stackDepth += 2;
					break;
				case TypeIds.T_void:
					break;
				default:
					this.stackDepth++;
					break;
			}
		}
	}

[srikanth-sankaran]

Stack trace is somewhat useful - but a reproducible test case will be very welcome.

[iloveeclipse]

@rfcom : could you please attach the source code that shows the problem?

@srikanth-sankaran : I assume something you will address anyway during switch refactoring work, right? The code in question that fails with NPE is very old, probably not a recent regression.

[srikanth-sankaran]

@rfcom : could you please attach the source code that shows the problem?

@srikanth-sankaran : I assume something you will address anyway during switch refactoring work, right? The code in question that fails with NPE is very old, probably not a recent regression.

Yes, I will follow up.

[srikanth-sankaran]

StackMapFrameCodeStream.recordExpressionType is dead! Long live StackMapFrameCodeStream.recordExpressionType! 😀

This was part of the ad-hoc stack size computation that #2171 attempts to eliminate with a streamlined and structured stack size tracking across branch arcs.

The method where the NPE is reported doesn't exist anymore and so the problem has been incinerated.

Closing as fixed by #2171