[GROOVY-10225] Unexpected NullPointerException during the "instruction selection" phase

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 4.0.0-beta-2
• Component/s: Static Type Checker
• Assignee: Eric Milles
• Reporter: Thodoris Sotiropoulos
• Created: 13/Sep/21 09:13
• Updated: 03/Feb/22 22:32
• Resolved: 27/Sep/21 22:11

Description

The following program

class Foo<Z> {
  final Z foo(Z x) {
    null;
  }
}
final class Bar<Y> {  final Foo<Y> bar() {
    new Foo<>()
  }
}
class Main {
  static final <F_O extends Number, F_X extends F_O> void test() {
    final F_X x = (F_X) null
    (new Bar<F_O>()).bar().foo(((false) ? x : (F_X) null))
  }
}

crashes the compiler and produces the following stacktrace

>>> a serious error occurred: BUG! exception in phase 'instruction selection' in source unit 'test.groovy' unexpected NullPointerException
>>> stacktrace:
BUG! exception in phase 'instruction selection' in source unit 'test.groovy' unexpected NullPointerException
        at org.codehaus.groovy.control.CompilationUnit$IPrimaryClassNodeOperation.doPhaseOperation(CompilationUnit.java:930)
        at org.codehaus.groovy.control.CompilationUnit.processPhaseOperations(CompilationUnit.java:654)
        at org.codehaus.groovy.control.CompilationUnit.compile(CompilationUnit.java:631)
        at org.codehaus.groovy.control.CompilationUnit.compile(CompilationUnit.java:607)
        at org.codehaus.groovy.tools.FileSystemCompiler.compile(FileSystemCompiler.java:311)
        at org.codehaus.groovy.tools.FileSystemCompiler.doCompilation(FileSystemCompiler.java:240)
        at org.codehaus.groovy.tools.FileSystemCompiler.commandLineCompile(FileSystemCompiler.java:165)
        at org.codehaus.groovy.tools.FileSystemCompiler.commandLineCompileWithErrorHandling(FileSystemCompiler.java:205)
        at org.codehaus.groovy.tools.FileSystemCompiler.main(FileSystemCompiler.java:189)
Caused by: java.lang.NullPointerException
        at org.codehaus.groovy.transform.stc.StaticTypeCheckingVisitor.resolvePlaceholdersFromImplicitTypeHints(StaticTypeCheckingVisitor.java:5439)
        at org.codehaus.groovy.transform.stc.StaticTypeCheckingVisitor.visitMethodCallExpression(StaticTypeCheckingVisitor.java:3596)
        at org.codehaus.groovy.transform.sc.StaticCompilationVisitor.visitMethodCallExpression(StaticCompilationVisitor.java:414)
        at org.codehaus.groovy.ast.expr.MethodCallExpression.visit(MethodCallExpression.java:77)
        at org.codehaus.groovy.ast.CodeVisitorSupport.visitExpressionStatement(CodeVisitorSupport.java:117)
        at org.codehaus.groovy.ast.ClassCodeVisitorSupport.visitExpressionStatement(ClassCodeVisitorSupport.java:204)
        at org.codehaus.groovy.transform.stc.StaticTypeCheckingVisitor.visitExpressionStatement(StaticTypeCheckingVisitor.java:2169)
        at org.codehaus.groovy.ast.stmt.ExpressionStatement.visit(ExpressionStatement.java:41)
        at org.codehaus.groovy.ast.CodeVisitorSupport.visitBlockStatement(CodeVisitorSupport.java:86)
        at org.codehaus.groovy.ast.ClassCodeVisitorSupport.visitBlockStatement(ClassCodeVisitorSupport.java:168)
        at org.codehaus.groovy.transform.stc.StaticTypeCheckingVisitor.visitBlockStatement(StaticTypeCheckingVisitor.java:3992)
        at org.codehaus.groovy.ast.stmt.BlockStatement.visit(BlockStatement.java:70)
        at org.codehaus.groovy.ast.ClassCodeVisitorSupport.visitClassCodeContainer(ClassCodeVisitorSupport.java:142)
        at org.codehaus.groovy.ast.ClassCodeVisitorSupport.visitConstructorOrMethod(ClassCodeVisitorSupport.java:115)
        at org.codehaus.groovy.transform.stc.StaticTypeCheckingVisitor.visitConstructorOrMethod(StaticTypeCheckingVisitor.java:2602)
        at org.codehaus.groovy.ast.ClassCodeVisitorSupport.visitMethod(ClassCodeVisitorSupport.java:110)
        at org.codehaus.groovy.transform.stc.StaticTypeCheckingVisitor.startMethodInference(StaticTypeCheckingVisitor.java:2591)
        at org.codehaus.groovy.transform.stc.StaticTypeCheckingVisitor.visitMethod(StaticTypeCheckingVisitor.java:2565)
        at org.codehaus.groovy.transform.sc.StaticCompilationVisitor.visitMethod(StaticCompilationVisitor.java:239)
        at org.codehaus.groovy.ast.ClassNode.visitMethods(ClassNode.java:1131)
        at org.codehaus.groovy.ast.ClassNode.visitContents(ClassNode.java:1124)
        at org.codehaus.groovy.ast.ClassCodeVisitorSupport.visitClass(ClassCodeVisitorSupport.java:52)
        at org.codehaus.groovy.transform.stc.StaticTypeCheckingVisitor.visitClass(StaticTypeCheckingVisitor.java:436)
        at org.codehaus.groovy.transform.sc.StaticCompilationVisitor.visitClass(StaticCompilationVisitor.java:197)
        at org.codehaus.groovy.transform.sc.StaticCompileTransformation.visit(StaticCompileTransformation.java:68)
        at org.codehaus.groovy.control.customizers.ASTTransformationCustomizer.call(ASTTransformationCustomizer.groovy:298)
        at org.codehaus.groovy.control.CompilationUnit$IPrimaryClassNodeOperation.doPhaseOperation(CompilationUnit.java:925)
 

Tested against master