[GROOVY-10344] STC crashes when bound has two wildcard types as type arguments

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 4.0.0-beta-1
• Fix Version/s: 4.0.0-beta-2, 2.5.18, 3.0.12
• Component/s: Static compilation, Static Type Checker
• Assignee: Eric Milles
• Reporter: Stefanos Chaliasos
• Created: 03/Nov/21 16:22
• Updated: 18/Jul/22 16:50
• Resolved: 04/Nov/21 16:37

Description

I have the following Groovy program.

@groovy.transform.CompileStatic
class Main {
  public static final void main() {
    final def x = ((B) null).foo(new A<>(), new A<>())
  }
}

class A<O, S> {}

interface B {
  abstract <F_P extends A<? extends Number, ? extends Number>> void foo(F_P y, F_P z)
}

Actual Behavior

The compiler crashes with the following stacktrace

>>> a serious error occurred: BUG! exception in phase 'instruction selection' in source unit 'Main.groovy' Expected earlier checking to detect generics parameter arity mismatch
Expected: A<O,S>
Supplied: A<F_P extends A<? extends java.lang.Number, ? extends java.lang.Number>>
>>> stacktrace:
BUG! exception in phase 'instruction selection' in source unit 'Main.groovy' Expected earlier checking to detect generics parameter arity mismatch
Expected: A<O,S>
Supplied: A<F_P extends A<? extends java.lang.Number, ? extends java.lang.Number>>
        at org.codehaus.groovy.ast.tools.GenericsUtils.extractPlaceholders(GenericsUtils.java:195)
        at org.codehaus.groovy.ast.tools.GenericsUtils.extractPlaceholders(GenericsUtils.java:146)
        at org.codehaus.groovy.ast.GenericsType.compareGenericsWithBound(GenericsType.java:368)
        at org.codehaus.groovy.ast.GenericsType.checkGenerics(GenericsType.java:292)
        at org.codehaus.groovy.ast.GenericsType.isCompatibleWith(GenericsType.java:244)
        at org.codehaus.groovy.transform.stc.StaticTypeCheckingSupport.applyGenericsConnections(StaticTypeCheckingSupport.java:1622)
        at org.codehaus.groovy.transform.stc.StaticTypeCheckingSupport.inferenceCheck(StaticTypeCheckingSupport.java:1528)
        at org.codehaus.groovy.transform.stc.StaticTypeCheckingSupport.typeCheckMethodsWithGenerics(StaticTypeCheckingSupport.java:1467)
        at org.codehaus.groovy.transform.stc.StaticTypeCheckingSupport.typeCheckMethodsWithGenerics(StaticTypeCheckingSupport.java:1415)
        at org.codehaus.groovy.transform.stc.StaticTypeCheckingVisitor.typeCheckMethodsWithGenericsOrFail(StaticTypeCheckingVisitor.java:5712)
        at org.codehaus.groovy.transform.stc.StaticTypeCheckingVisitor.visitMethodCallExpression(StaticTypeCheckingVisitor.java:3524)
        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.transform.stc.StaticTypeCheckingVisitor.visitBinaryExpression(StaticTypeCheckingVisitor.java:791)
        at org.codehaus.groovy.ast.CodeVisitorSupport.visitDeclarationExpression(CodeVisitorSupport.java:335)
        at org.codehaus.groovy.ast.ClassCodeVisitorSupport.visitDeclarationExpression(ClassCodeVisitorSupport.java:154)
        at org.codehaus.groovy.ast.expr.DeclarationExpression.visit(DeclarationExpression.java:89)
        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:2190)
        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:3935)
        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:2596)
        at org.codehaus.groovy.ast.ClassCodeVisitorSupport.visitMethod(ClassCodeVisitorSupport.java:110)
        at org.codehaus.groovy.transform.stc.StaticTypeCheckingVisitor.startMethodInference(StaticTypeCheckingVisitor.java:2585)
        at org.codehaus.groovy.transform.stc.StaticTypeCheckingVisitor.visitMethod(StaticTypeCheckingVisitor.java:2559)
        at org.codehaus.groovy.transform.sc.StaticCompilationVisitor.visitMethod(StaticCompilationVisitor.java:239)
        at org.codehaus.groovy.ast.ClassNode.visitMethods(ClassNode.java:1134)
        at org.codehaus.groovy.ast.ClassNode.visitContents(ClassNode.java:1127)
        at org.codehaus.groovy.ast.ClassCodeVisitorSupport.visitClass(ClassCodeVisitorSupport.java:52)
        at org.codehaus.groovy.transform.stc.StaticTypeCheckingVisitor.visitClass(StaticTypeCheckingVisitor.java:438)
        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.transform.ASTTransformationVisitor.visitClass(ASTTransformationVisitor.java:146)
        at org.codehaus.groovy.transform.ASTTransformationVisitor.lambda$addPhaseOperations$2(ASTTransformationVisitor.java:229)
        at org.codehaus.groovy.control.CompilationUnit$IPrimaryClassNodeOperation.doPhaseOperation(CompilationUnit.java:911)
        at org.codehaus.groovy.control.CompilationUnit.processPhaseOperations(CompilationUnit.java:653)
        at org.codehaus.groovy.control.CompilationUnit.compile(CompilationUnit.java:630)
        at org.codehaus.groovy.control.CompilationUnit.compile(CompilationUnit.java:609)
        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)

Comment

javac rejects the equivalent Java program because it cannot infer the type for variable x. I'm not sure if groovyc could infer the type of this variable.

Affected Version

master (commit: cee45d768bb65d1254a61a6dd4ce3c6a1f2ee3ca ).