build: disable Groovy invokedynamic for the Grails 8 compile

build-logic/docs-core/build.gradle

@@ -71,6 +71,10 @@ sourceSets {
     }
 }
 
+// docs-core does not apply org.apache.grails.buildsrc.compile. Keep the same
+// Grails 8 default (indy off) as CompilePlugin. See #15293.
+apply from: layout.projectDirectory.file('../../gradle/groovy-indy.gradle')
+
 def docFilesJar = tasks.register('docFilesJar', Jar)
 docFilesJar.configure {Jar it ->
     it.description = 'Package up files used for generating documentation.'

build-logic/plugins/build.gradle

@@ -57,6 +57,10 @@ tasks.named('test') {
     useJUnitPlatform()
 }
 
+// This project compiles CompilePlugin itself, so it cannot apply that plugin.
+// Keep the same Grails 8 default (indy off) as CompilePlugin. See #15293.
+apply from: layout.projectDirectory.file('../../gradle/groovy-indy.gradle')
+
 gradlePlugin {
     plugins {
         register('compilePlugin') {

build-logic/plugins/src/main/groovy/org/apache/grails/buildsrc/CompilePlugin.groovy

@@ -35,6 +35,7 @@ import org.gradle.api.tasks.compile.JavaCompile
 import org.gradle.api.tasks.javadoc.Javadoc
 import org.gradle.external.javadoc.StandardJavadocDocletOptions
 
+import static org.apache.grails.buildsrc.GradleUtils.lookupProperty
 import static org.apache.grails.buildsrc.GradleUtils.lookupPropertyByType
 
 @CompileStatic
@@ -107,6 +108,12 @@ class CompilePlugin implements Plugin<Project> {
                 it.groovyOptions.encoding = StandardCharsets.UTF_8.name()
                 // Preserve method parameter names in Groovy/Java classes for IDE parameter hints & bean reflection metadata.
                 it.groovyOptions.parameters = true
+                // Grails 8 keeps invokedynamic off. Groovy 5's compiler default is indy=true,
+                // which is a large runtime regression for dynamic Groovy (see #15293). Modules
+                // that do not apply the Grails Gradle plugin would otherwise inherit that
+                // default. Grails 9 / Groovy 6 can flip this. CI can still opt in with
+                // -PgrailsIndy=true (same property as grails-extension-gradle-config.gradle).
+                it.groovyOptions.optimizationOptions.put('indy', lookupProperty(project, 'grailsIndy', false))
                 // encoding needs to be the same since it's different across platforms
                 it.options.encoding = StandardCharsets.UTF_8.name()
                 it.options.fork = true

build-logic/plugins/src/test/groovy/org/apache/grails/buildsrc/CompilePluginSpec.groovy

@@ -0,0 +1,103 @@
+/*
+ *  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
+ *
+ *    https://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 org.apache.grails.buildsrc
+
+import org.gradle.testkit.runner.GradleRunner
+import org.gradle.testkit.runner.TaskOutcome
+import spock.lang.Specification
+import spock.lang.TempDir
+
+import java.nio.file.Path
+
+class CompilePluginSpec extends Specification {
+
+    @TempDir
+    Path testProjectDir
+
+    def setup() {
+        testProjectDir.resolve('settings.gradle').toFile().text = ''
+        testProjectDir.resolve('.asf.yaml').toFile().text = ''
+        def configScript = testProjectDir.resolve('gradle/groovy-compile-configscript.groovy').toFile()
+        configScript.parentFile.mkdirs()
+        configScript.text = ''
+        testProjectDir.resolve('build.gradle').toFile().text = """
+            plugins {
+                id 'groovy'
+                id 'org.apache.grails.buildsrc.compile'
+            }
+
+            ext {
+                javaVersion = 21
+                grailsVersion = '8.0.0-SNAPSHOT'
+                formattedBuildDate = '2026-01-01'
+            }
+
+            repositories {
+                mavenCentral()
+            }
+
+            tasks.register('printIndy') {
+                def compileTask = tasks.named('compileGroovy', org.gradle.api.tasks.compile.GroovyCompile)
+                def testCompileTask = tasks.named('compileTestGroovy', org.gradle.api.tasks.compile.GroovyCompile)
+                doLast {
+                    println "MAIN_INDY=\${compileTask.get().groovyOptions.optimizationOptions.indy}"
+                    println "TEST_INDY=\${testCompileTask.get().groovyOptions.optimizationOptions.indy}"
+                }
+            }
+        """
+    }
+
+    def "disables invokedynamic on GroovyCompile tasks by default"() {
+        when:
+        def result = runPrintIndy()
+
+        then:
+        result.task(':printIndy').outcome == TaskOutcome.SUCCESS
+        result.output.contains('MAIN_INDY=false')
+        result.output.contains('TEST_INDY=false')
+    }
+
+    def "enables invokedynamic when grailsIndy is true"() {
+        when:
+        def result = runPrintIndy('-PgrailsIndy=true')
+
+        then:
+        result.task(':printIndy').outcome == TaskOutcome.SUCCESS
+        result.output.contains('MAIN_INDY=true')
+        result.output.contains('TEST_INDY=true')
+    }
+
+    def "trims whitespace when parsing grailsIndy"() {
+        when:
+        def result = runPrintIndy('-PgrailsIndy= true ')
+
+        then:
+        result.task(':printIndy').outcome == TaskOutcome.SUCCESS
+        result.output.contains('MAIN_INDY=true')
+        result.output.contains('TEST_INDY=true')
+    }
+
+    private def runPrintIndy(String... extraArgs) {
+        GradleRunner.create()
+                .withProjectDir(testProjectDir.toFile())
+                .withArguments(['printIndy', '--stacktrace'] + (extraArgs as List))
+                .withPluginClasspath()
+                .build()
+    }
+}

build.gradle

@@ -109,6 +109,8 @@ final class ActiveProcessorCountArgumentProvider implements CommandLineArgumentP
 
 subprojects {
 
+    apply from: rootProject.layout.projectDirectory.file('gradle/groovy-indy.gradle')
+
     tasks.withType(Test).configureEach { testTask ->
         testTask.jvmArgumentProviders.add(new ActiveProcessorCountArgumentProvider(
                 Runtime.runtime.availableProcessors(), gradle.startParameter.maxWorkerCount))

gradle/grails-extension-gradle-config.gradle

@@ -35,7 +35,9 @@ grails {
     // Allow CI to toggle Groovy invokedynamic (indy) via -PgrailsIndy=true
     // This enables testing functional tests with both indy enabled and disabled.
     // See: https://github.com/apache/grails-core/issues/15321
+    // Framework modules that do not apply this plugin inherit the same default
+    // from org.apache.grails.buildsrc.compile (CompilePlugin).
     if (project.hasProperty('grailsIndy')) {
-        indy = Boolean.parseBoolean(project.property('grailsIndy') as String)
+        indy = project.property('grailsIndy').toString().trim().toBoolean()
     }
 }

gradle/groovy-indy.gradle

@@ -0,0 +1,34 @@
+/*
+ *  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
+ *
+ *    https://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.
+ */
+
+// Grails 8 keeps invokedynamic off. Groovy 5's compiler default is indy=true,
+// which is a large runtime regression for dynamic Groovy (see #15293).
+// Applied from each independent build (grails-core, grails-gradle, grails-forge)
+// so modules that never apply the Grails Gradle plugin still inherit this.
+// Grails 9 / Groovy 6 can flip the default. CI can still opt in with -PgrailsIndy=true.
+boolean grailsIndyEnabled = false
+if (project.hasProperty('grailsIndy')) {
+    grailsIndyEnabled = project.property('grailsIndy').toString().trim().toBoolean()
+}
+
+project.pluginManager.withPlugin('groovy') {
+    project.tasks.withType(org.gradle.api.tasks.compile.GroovyCompile).configureEach { compileTask ->
+        compileTask.groovyOptions.optimizationOptions.indy = grailsIndyEnabled
+    }
+}

grails-databinding-core/src/main/groovy/grails/databinding/SimpleDataBinder.groovy

@@ -29,6 +29,7 @@ import groovy.transform.CompileStatic
 import groovy.transform.TypeCheckingMode
 import groovy.xml.slurpersupport.GPathResult
 import org.codehaus.groovy.reflection.CachedMethod
+import org.codehaus.groovy.runtime.InvokerHelper
 
 import grails.databinding.converters.FormattedValueConverter
 import grails.databinding.converters.ValueConverter
@@ -430,12 +431,24 @@ class SimpleDataBinder implements DataBinder {
         try {
             instance = referencedType.getDeclaredConstructor().newInstance()
         } catch (NoSuchMethodException | IllegalAccessException ignored) {
-            return referencedType.newInstance(values)
+            return newInstanceFromMapArguments(referencedType, values)
         }
         bind(instance, new SimpleMapDataBindingSource(values), listener)
         instance
     }
 
+    /**
+     * Invoke a {@code Map} constructor without calling Groovy's
+     * {@code Class.newInstance(Map)}. Under {@code @CompileStatic} with
+     * invokedynamic disabled that extension is not selected, so nested
+     * objects with only a Map constructor are left unbound.
+     */
+    protected Object newInstanceFromMapArguments(Class referencedType, Map values) {
+        // Pass an Object[] so CompileStatic cannot treat the Map as named
+        // arguments or coerce it to a multi-arg constructor signature.
+        InvokerHelper.invokeConstructorOf(referencedType, new Object[] { values })
+    }
+
     @CompileStatic(TypeCheckingMode.SKIP)
     protected initializeArray(obj, String propertyName, Class arrayType, int index) {
         Object[] array = obj[propertyName]

grails-datamapping-core/src/main/groovy/org/grails/datastore/gorm/GormStaticApi.groovy

@@ -377,15 +377,20 @@ class GormStaticApi<D> extends AbstractGormApi<D> implements GormAllOperations<D
 
     @Override
     Integer count() {
-        log.debug('GormStaticApi.count() called for {}', persistentClass.name)
+        // Capture the @Slf4j logger before entering the SessionCallback. With
+        // invokedynamic off (Grails 8 default), log.debug(...) inside that
+        // closure is dispatched through methodMissing as a dynamic finder on
+        // the persistent class (MissingMethodException: debug).
+        def logger = log
+        logger.debug('GormStaticApi.count() called for {}', persistentClass.name)
         Integer result = execute({ Session session ->
             def query = session.createQuery(persistentClass)
             query.projections().count()
             def res = query.singleResult()
-            log.debug('Query singleResult returned {}', res)
+            logger.debug('Query singleResult returned {}', res)
             res instanceof Number ? ((Number)res).intValue() : 0
         } as SessionCallback<Integer>)
-        log.debug('count() result is {}', result)
+        logger.debug('count() result is {}', result)
         return result
     }
 

grails-datamapping-core/src/test/groovy/org/grails/datastore/gorm/GormStaticApiSpec.groovy

@@ -100,6 +100,17 @@ class GormStaticApiSpec extends Specification {
         api.executeQualified(ConnectionSource.DEFAULT, { Session session -> 'ran' }) == 'ran'
     }
 
+    void "count() does not dispatch log.debug through methodMissing"() {
+        given:
+        def api = new GormStaticApi(GormStaticApiThing, datastore, [])
+
+        when:
+        Integer n = api.count()
+
+        then:
+        n == 0
+    }
+
     void "getGormDynamicFinders returns the finders the api was constructed with"() {
         given:
         def finder = Stub(org.grails.datastore.gorm.finders.FinderMethod)

grails-forge/build.gradle

@@ -83,6 +83,8 @@ allprojects {
 }
 
 subprojects {
+    apply from: rootProject.layout.projectDirectory.file('../gradle/groovy-indy.gradle')
+
     configurations.configureEach {
         resolutionStrategy {
             def cacheHours = isCiBuild || isReproducibleBuild ? 0 : 24

grails-gradle/build.gradle

@@ -72,6 +72,8 @@ final class ActiveProcessorCountArgumentProvider implements CommandLineArgumentP
 }
 
 subprojects {
+    apply from: rootProject.layout.projectDirectory.file('../gradle/groovy-indy.gradle')
+
     tasks.withType(Test).configureEach { testTask ->
         testTask.jvmArgumentProviders.add(new ActiveProcessorCountArgumentProvider(
                 Runtime.runtime.availableProcessors(), gradle.startParameter.maxWorkerCount))

grails-test-suite-persistence/src/test/groovy/grails/web/databinding/GrailsWebDataBinderSpec.groovy

@@ -2163,7 +2163,8 @@ class SecureMapConstructorValue implements Validateable {
 
     SecureMapConstructorValue(Map values) {
         name = values.name
-        admin = values.admin as boolean
+        // Groovy 5 without invokedynamic throws on `null as boolean`.
+        admin = Boolean.TRUE.equals(values.admin)
     }
 
     static constraints = {

grails-web-databinding/src/main/groovy/grails/web/databinding/GrailsWebDataBinder.groovy

@@ -641,7 +641,8 @@ class GrailsWebDataBinder extends SimpleDataBinder {
             if (value instanceof Map) {
                 if (isBindAllIncludeList(includeList) ||
                         !DataBindingUtils.isDenyByDefaultEnabled()) {
-                    return referencedType.newInstance(filterUnbindableMapConstructorArguments(referencedType, (Map) value))
+                    return newInstanceFromMapArguments(referencedType,
+                            filterUnbindableMapConstructorArguments(referencedType, (Map) value))
                 }
                 if (DataBindingUtils.isGeneratedBindingIncludeList(bindingIncludeList.get())) {
                     warnAboutMissingNoArgConstructor(referencedType)