This is an automated email from the ASF dual-hosted git repository. paulk-asert pushed a commit to branch GROOVY_5_0_X in repository https://gitbox.apache.org/repos/asf/groovy.git
commit 1c49437ba60d0594550a00950aed2f69bdbd13ce Author: Paul King <[email protected]> AuthorDate: Tue Jul 14 10:16:27 2026 +1000 GROOVY-12154: box primitive lambda param when the target SAM param is a reference type A @CompileStatic lambda declaring a primitive parameter (e.g. (int a) -> ...) against a generic functional interface (e.g. Function<Integer,Integer>) compiled cleanly but threw at runtime: java.lang.invoke.LambdaConversionException: int is not a subtype of class java.lang.Object AbstractFunctionalInterfaceWriter.convertParameterType always emitted a primitive implementation-method parameter when the lambda declared a primitive, ignoring the target (functional-interface) parameter type. But LambdaMetafactory links against the erased SAM signature (Object) and will not unbox to a primitive, so the implementation method must accept the boxed type when the SAM parameter is a reference type. It stays primitive only when the SAM parameter is itself primitive (e.g. IntUnaryOperator), preserving GROOVY-9790. Backport of 86c6648d1e from master. --- .../asm/sc/AbstractFunctionalInterfaceWriter.java | 16 ++- src/test/groovy/bugs/Groovy12154.groovy | 112 +++++++++++++++++++++ 2 files changed, 123 insertions(+), 5 deletions(-) diff --git a/src/main/java/org/codehaus/groovy/classgen/asm/sc/AbstractFunctionalInterfaceWriter.java b/src/main/java/org/codehaus/groovy/classgen/asm/sc/AbstractFunctionalInterfaceWriter.java index ceb280c43b..d2017a76b1 100644 --- a/src/main/java/org/codehaus/groovy/classgen/asm/sc/AbstractFunctionalInterfaceWriter.java +++ b/src/main/java/org/codehaus/groovy/classgen/asm/sc/AbstractFunctionalInterfaceWriter.java @@ -116,12 +116,18 @@ public interface AbstractFunctionalInterfaceWriter { ClassNode type; if (isPrimitiveType(parameterType)) { - if (!isPrimitiveType(inferredType)) { - // The non-primitive type and primitive type are not allowed to mix since Java 9+ - // java.lang.invoke.LambdaConversionException: Type mismatch for instantiated parameter 0: class java.lang.Integer is not a subtype of int - type = getUnwrapper(inferredType).getPlainNodeReference(false); + // The lambda parameter is declared with a primitive type; reduce the inferred type to it. + ClassNode primitive = isPrimitiveType(inferredType) ? inferredType : getUnwrapper(inferredType); + if (isPrimitiveType(targetType)) { + // The functional-interface parameter is itself primitive, so the implementation method + // stays primitive (GROOVY-9790: otherwise "Integer is not a subtype of int"). + type = primitive.getPlainNodeReference(false); } else { - type = inferredType.getPlainNodeReference(false); + // GROOVY-12154: the functional-interface parameter is a reference type, so the + // implementation method must accept the BOXED type -- LambdaMetafactory links against + // the erased SAM signature (Object) and will not unbox to a primitive + // (java.lang.invoke.LambdaConversionException: int is not a subtype of class java.lang.Object). + type = getWrapper(primitive).getPlainNodeReference(); } } else if (isPrimitiveType(inferredType)) { // GROOVY-9790: bootstrap method initialization exception raised when lambda parameter type is wrong diff --git a/src/test/groovy/bugs/Groovy12154.groovy b/src/test/groovy/bugs/Groovy12154.groovy new file mode 100644 index 0000000000..489439a7d7 --- /dev/null +++ b/src/test/groovy/bugs/Groovy12154.groovy @@ -0,0 +1,112 @@ +/* + * Licensed to the Apache Software Foundation (ASF) under one + * or more contributor license agreements. See the NOTICE file + * distributed with this work for additional information + * regarding copyright ownership. The ASF licenses this file + * to you under the Apache License, Version 2.0 (the + * "License"); you may not use this file except in compliance + * with the License. You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, + * software distributed under the License is distributed on an + * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY + * KIND, either express or implied. See the License for the + * specific language governing permissions and limitations + * under the License. + */ +package bugs + +import org.junit.jupiter.api.Test + +import static groovy.test.GroovyAssert.assertScript + +final class Groovy12154 { + + // A lambda with a primitive-typed parameter targeting a generic functional interface used to + // compile cleanly but throw at runtime (LambdaConversionException: int is not a subtype of + // class java.lang.Object), because the implementation method kept the primitive parameter type + // while LambdaMetafactory links against the erased (reference) SAM signature. + + @Test + void testPrimitiveParamTargetingGenericSam() { + assertScript ''' + import java.util.function.Function + @groovy.transform.CompileStatic + class T { + Function<Integer, Integer> f = (int a) -> a * 2 + Integer m() { f.apply(5) } + } + assert new T().m() == 10 + ''' + } + + @Test + void testMultiplePrimitiveParamsTargetingGenericSam() { + assertScript ''' + import java.util.function.BiFunction + @groovy.transform.CompileStatic + class T { + BiFunction<Integer, Integer, Integer> f = (int a, int b) -> a + b + List m() { [f.apply(1, 2), f.apply(5, 5)] } + } + assert new T().m() == [3, 10] + ''' + } + + @Test + void testPrimitiveParamWithDefaultTargetingGenericSam() { + assertScript ''' + import java.util.function.BiFunction + @groovy.transform.CompileStatic + class T { + BiFunction<Integer, Integer, Integer> f = (int a, int b = 10) -> a + b + List m() { [f.apply(1, 2), f.apply(5, 5)] } + } + assert new T().m() == [3, 10] + ''' + } + + @Test + void testLongPrimitiveParamTargetingGenericSam() { + assertScript ''' + import java.util.function.Function + @groovy.transform.CompileStatic + class T { + Function<Long, Long> f = (long a) -> a * 2L + Long m() { f.apply(5L) } + } + assert new T().m() == 10L + ''' + } + + // Regressions: a primitive-parameter functional interface must still use a primitive impl param. + + @Test + void testPrimitiveParamTargetingPrimitiveSam() { + assertScript ''' + import java.util.function.IntUnaryOperator + @groovy.transform.CompileStatic + class T { + IntUnaryOperator f = (int a) -> a * 2 + int m() { f.applyAsInt(5) } + } + assert new T().m() == 10 + ''' + } + + @Test + void testUntypedAndBoxedParamsUnaffected() { + assertScript ''' + import java.util.function.Function + @groovy.transform.CompileStatic + class T { + Function<Integer, Integer> u = (a) -> a * 2 + Function<Integer, Integer> b = (Integer a) -> a * 2 + List m() { [u.apply(5), b.apply(5)] } + } + assert new T().m() == [10, 10] + ''' + } +}
