java.lang.Assertion在添加带参数的生成方法时由编译器抛出的错误

时间：2017-10-22 12:34:45

标签： java code-generation sun

我正在使用带有注释处理器的内部sun API（com.sun.tools.javac）修改现有类。我可以使用以下代码生成MethodDecl ClassDecl并添加JCTree.JCClassDecl classDecl = ... JCTree.JCMethodDecl methodDecl = ... JCTree[] trees = new JCTree[classDecl.defs.length() + 1]; trees[classDecl.defs.length()] = methodDecl; classDecl.defs = List.from(trees); ：

MethodDecl

这很好用，直到我尝试将参数添加到方法声明中。我使用以下代码生成新的Map<String, Class<?>> paramMap = ... List<JCVariableDecl> parameters = List.from(paramMap.entrySet().stream() .map(e -> treeMaker.VarDef(treeMaker.Modifiers(Flags.PARAMETER), elements.getName(e.getKey()), getType(e.getValue()), null)) .toArray(JCVariableDecl[]::new)); ... JCMethodDecl methodDecl = treeMaker.MethodDef(modifiers, methodName, returnType, genericParameters, parameters, throwables, methodBody, null); ：

An exception has occurred in the compiler (9). Please file a bug against the Java compiler via the Java bug reporting page (http://bugreport.java.com) after checking the Bug Database (http://bugs.java.com) for duplicates. Include your program and the following diagnostic in your report. Thank you.
java.lang.AssertionError
    at jdk.compiler/com.sun.tools.javac.util.Assert.error(Assert.java:155)
    at jdk.compiler/com.sun.tools.javac.util.Assert.check(Assert.java:46)
    at jdk.compiler/com.sun.tools.javac.util.Bits.incl(Bits.java:186)
    at jdk.compiler/com.sun.tools.javac.comp.Flow$AssignAnalyzer.initParam(Flow.java:1931)
    at jdk.compiler/com.sun.tools.javac.comp.Flow$AssignAnalyzer.visitMethodDef(Flow.java:1880)
    at jdk.compiler/com.sun.tools.javac.tree.JCTree$JCMethodDecl.accept(JCTree.java:866)
    at jdk.compiler/com.sun.tools.javac.tree.TreeScanner.scan(TreeScanner.java:49)
    at jdk.compiler/com.sun.tools.javac.comp.Flow$BaseAnalyzer.scan(Flow.java:393)
    at jdk.compiler/com.sun.tools.javac.comp.Flow$AssignAnalyzer.scan(Flow.java:1451)
    at jdk.compiler/com.sun.tools.javac.comp.Flow$AssignAnalyzer.visitClassDef(Flow.java:1822)
    at jdk.compiler/com.sun.tools.javac.tree.JCTree$JCClassDecl.accept(JCTree.java:774)
    at jdk.compiler/com.sun.tools.javac.tree.TreeScanner.scan(TreeScanner.java:49)
    at jdk.compiler/com.sun.tools.javac.comp.Flow$BaseAnalyzer.scan(Flow.java:393)
    at jdk.compiler/com.sun.tools.javac.comp.Flow$AssignAnalyzer.scan(Flow.java:1451)
    at jdk.compiler/com.sun.tools.javac.comp.Flow$AssignAnalyzer.analyzeTree(Flow.java:2521)
    at jdk.compiler/com.sun.tools.javac.comp.Flow$AssignAnalyzer.analyzeTree(Flow.java:2504)
    at jdk.compiler/com.sun.tools.javac.comp.Flow.analyzeTree(Flow.java:212)
    at jdk.compiler/com.sun.tools.javac.main.JavaCompiler.flow(JavaCompiler.java:1389)
    at jdk.compiler/com.sun.tools.javac.main.JavaCompiler.flow(JavaCompiler.java:1363)
    at jdk.compiler/com.sun.tools.javac.main.JavaCompiler.compile(JavaCompiler.java:959)
    at jdk.compiler/com.sun.tools.javac.api.JavacTaskImpl.lambda$doCall$0(JavacTaskImpl.java:100)
    at jdk.compiler/com.sun.tools.javac.api.JavacTaskImpl.handleExceptions(JavacTaskImpl.java:142)
    at jdk.compiler/com.sun.tools.javac.api.JavacTaskImpl.doCall(JavacTaskImpl.java:96)
    at jdk.compiler/com.sun.tools.javac.api.JavacTaskImpl.call(JavacTaskImpl.java:90)
    at org.gradle.api.internal.tasks.compile.JdkJavaCompiler.execute(JdkJavaCompiler.java:49)
    at org.gradle.api.internal.tasks.compile.JdkJavaCompiler.execute(JdkJavaCompiler.java:36)
    at org.gradle.api.internal.tasks.compile.NormalizingJavaCompiler.delegateAndHandleErrors(NormalizingJavaCompiler.java:99)
    at org.gradle.api.internal.tasks.compile.NormalizingJavaCompiler.execute(NormalizingJavaCompiler.java:52)
    at org.gradle.api.internal.tasks.compile.NormalizingJavaCompiler.execute(NormalizingJavaCompiler.java:37)
    at org.gradle.api.internal.tasks.compile.CleaningJavaCompilerSupport.execute(CleaningJavaCompilerSupport.java:35)
    at org.gradle.api.internal.tasks.compile.CleaningJavaCompilerSupport.execute(CleaningJavaCompilerSupport.java:25)
    at org.gradle.api.tasks.compile.JavaCompile.performCompilation(JavaCompile.java:204)
    at org.gradle.api.tasks.compile.JavaCompile.compile(JavaCompile.java:189)
    at org.gradle.api.tasks.compile.JavaCompile.compile(JavaCompile.java:121)
    at jdk.internal.reflect.GeneratedMethodAccessor170.invoke(Unknown Source)
    at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.base/java.lang.reflect.Method.invoke(Method.java:564)
    at org.gradle.internal.reflect.JavaMethod.invoke(JavaMethod.java:73)
    at org.gradle.api.internal.project.taskfactory.DefaultTaskClassInfoStore$IncrementalTaskAction.doExecute(DefaultTaskClassInfoStore.java:179)
    at org.gradle.api.internal.project.taskfactory.DefaultTaskClassInfoStore$StandardTaskAction.execute(DefaultTaskClassInfoStore.java:135)
    at org.gradle.api.internal.project.taskfactory.DefaultTaskClassInfoStore$StandardTaskAction.execute(DefaultTaskClassInfoStore.java:122)
    at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter$1.run(ExecuteActionsTaskExecuter.java:121)
    at org.gradle.internal.progress.DefaultBuildOperationExecutor$RunnableBuildOperationWorker.execute(DefaultBuildOperationExecutor.java:336)
    at org.gradle.internal.progress.DefaultBuildOperationExecutor$RunnableBuildOperationWorker.execute(DefaultBuildOperationExecutor.java:328)
    at org.gradle.internal.progress.DefaultBuildOperationExecutor.execute(DefaultBuildOperationExecutor.java:199)
    at org.gradle.internal.progress.DefaultBuildOperationExecutor.run(DefaultBuildOperationExecutor.java:110)
    at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter.executeAction(ExecuteActionsTaskExecuter.java:110)
    at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter.executeActions(ExecuteActionsTaskExecuter.java:92)
    at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter.execute(ExecuteActionsTaskExecuter.java:70)
    at org.gradle.api.internal.tasks.execution.SkipUpToDateTaskExecuter.execute(SkipUpToDateTaskExecuter.java:62)
    at org.gradle.api.internal.tasks.execution.ResolveTaskOutputCachingStateExecuter.execute(ResolveTaskOutputCachingStateExecuter.java:54)
    at org.gradle.api.internal.tasks.execution.ValidatingTaskExecuter.execute(ValidatingTaskExecuter.java:58)
    at org.gradle.api.internal.tasks.execution.SkipEmptySourceFilesTaskExecuter.execute(SkipEmptySourceFilesTaskExecuter.java:97)
    at org.gradle.api.internal.tasks.execution.CleanupStaleOutputsExecuter.execute(CleanupStaleOutputsExecuter.java:87)
    at org.gradle.api.internal.tasks.execution.ResolveTaskArtifactStateTaskExecuter.execute(ResolveTaskArtifactStateTaskExecuter.java:52)
    at org.gradle.api.internal.tasks.execution.SkipTaskWithNoActionsExecuter.execute(SkipTaskWithNoActionsExecuter.java:52)
    at org.gradle.api.internal.tasks.execution.SkipOnlyIfTaskExecuter.execute(SkipOnlyIfTaskExecuter.java:54)
    at org.gradle.api.internal.tasks.execution.ExecuteAtMostOnceTaskExecuter.execute(ExecuteAtMostOnceTaskExecuter.java:43)
    at org.gradle.api.internal.tasks.execution.CatchExceptionTaskExecuter.execute(CatchExceptionTaskExecuter.java:34)
    at org.gradle.execution.taskgraph.DefaultTaskGraphExecuter$EventFiringTaskWorker$1.run(DefaultTaskGraphExecuter.java:248)
    at org.gradle.internal.progress.DefaultBuildOperationExecutor$RunnableBuildOperationWorker.execute(DefaultBuildOperationExecutor.java:336)
    at org.gradle.internal.progress.DefaultBuildOperationExecutor$RunnableBuildOperationWorker.execute(DefaultBuildOperationExecutor.java:328)
    at org.gradle.internal.progress.DefaultBuildOperationExecutor.execute(DefaultBuildOperationExecutor.java:199)
    at org.gradle.internal.progress.DefaultBuildOperationExecutor.run(DefaultBuildOperationExecutor.java:110)
    at org.gradle.execution.taskgraph.DefaultTaskGraphExecuter$EventFiringTaskWorker.execute(DefaultTaskGraphExecuter.java:241)
    at org.gradle.execution.taskgraph.DefaultTaskGraphExecuter$EventFiringTaskWorker.execute(DefaultTaskGraphExecuter.java:230)
    at org.gradle.execution.taskgraph.DefaultTaskPlanExecutor$TaskExecutorWorker.processTask(DefaultTaskPlanExecutor.java:123)
    at org.gradle.execution.taskgraph.DefaultTaskPlanExecutor$TaskExecutorWorker.access$200(DefaultTaskPlanExecutor.java:79)
    at org.gradle.execution.taskgraph.DefaultTaskPlanExecutor$TaskExecutorWorker$1.execute(DefaultTaskPlanExecutor.java:104)
    at org.gradle.execution.taskgraph.DefaultTaskPlanExecutor$TaskExecutorWorker$1.execute(DefaultTaskPlanExecutor.java:98)
    at org.gradle.execution.taskgraph.DefaultTaskExecutionPlan.execute(DefaultTaskExecutionPlan.java:625)
    at org.gradle.execution.taskgraph.DefaultTaskExecutionPlan.executeWithTask(DefaultTaskExecutionPlan.java:580)
    at org.gradle.execution.taskgraph.DefaultTaskPlanExecutor$TaskExecutorWorker.run(DefaultTaskPlanExecutor.java:98)
    at org.gradle.execution.taskgraph.DefaultTaskPlanExecutor.process(DefaultTaskPlanExecutor.java:59)
    at org.gradle.execution.taskgraph.DefaultTaskGraphExecuter.execute(DefaultTaskGraphExecuter.java:128)
    at org.gradle.execution.SelectedTaskExecutionAction.execute(SelectedTaskExecutionAction.java:37)
    at org.gradle.execution.DefaultBuildExecuter.execute(DefaultBuildExecuter.java:37)
    at org.gradle.execution.DefaultBuildExecuter.access$000(DefaultBuildExecuter.java:23)
    at org.gradle.execution.DefaultBuildExecuter$1.proceed(DefaultBuildExecuter.java:43)
    at org.gradle.execution.DryRunBuildExecutionAction.execute(DryRunBuildExecutionAction.java:46)
    at org.gradle.execution.DefaultBuildExecuter.execute(DefaultBuildExecuter.java:37)
    at org.gradle.execution.DefaultBuildExecuter.execute(DefaultBuildExecuter.java:30)
    at org.gradle.initialization.DefaultGradleLauncher$ExecuteTasks.run(DefaultGradleLauncher.java:314)
    at org.gradle.internal.progress.DefaultBuildOperationExecutor$RunnableBuildOperationWorker.execute(DefaultBuildOperationExecutor.java:336)
    at org.gradle.internal.progress.DefaultBuildOperationExecutor$RunnableBuildOperationWorker.execute(DefaultBuildOperationExecutor.java:328)
    at org.gradle.internal.progress.DefaultBuildOperationExecutor.execute(DefaultBuildOperationExecutor.java:199)
    at org.gradle.internal.progress.DefaultBuildOperationExecutor.run(DefaultBuildOperationExecutor.java:110)
    at org.gradle.initialization.DefaultGradleLauncher.runTasks(DefaultGradleLauncher.java:204)
    at org.gradle.initialization.DefaultGradleLauncher.doBuildStages(DefaultGradleLauncher.java:134)
    at org.gradle.initialization.DefaultGradleLauncher.executeTasks(DefaultGradleLauncher.java:109)
    at org.gradle.internal.invocation.GradleBuildController$1.call(GradleBuildController.java:78)
    at org.gradle.internal.invocation.GradleBuildController$1.call(GradleBuildController.java:75)
    at org.gradle.internal.work.DefaultWorkerLeaseService.withLocks(DefaultWorkerLeaseService.java:152)
    at org.gradle.internal.invocation.GradleBuildController.doBuild(GradleBuildController.java:100)
    at org.gradle.internal.invocation.GradleBuildController.run(GradleBuildController.java:75)
    at org.gradle.tooling.internal.provider.runner.BuildModelActionRunner.run(BuildModelActionRunner.java:53)
    at org.gradle.launcher.exec.ChainingBuildActionRunner.run(ChainingBuildActionRunner.java:35)
    at org.gradle.launcher.exec.ChainingBuildActionRunner.run(ChainingBuildActionRunner.java:35)
    at org.gradle.tooling.internal.provider.ValidatingBuildActionRunner.run(ValidatingBuildActionRunner.java:32)
    at org.gradle.launcher.exec.RunAsBuildOperationBuildActionRunner$1.run(RunAsBuildOperationBuildActionRunner.java:43)
    at org.gradle.internal.progress.DefaultBuildOperationExecutor$RunnableBuildOperationWorker.execute(DefaultBuildOperationExecutor.java:336)
    at org.gradle.internal.progress.DefaultBuildOperationExecutor$RunnableBuildOperationWorker.execute(DefaultBuildOperationExecutor.java:328)
    at org.gradle.internal.progress.DefaultBuildOperationExecutor.execute(DefaultBuildOperationExecutor.java:199)
    at org.gradle.internal.progress.DefaultBuildOperationExecutor.run(DefaultBuildOperationExecutor.java:110)
    at org.gradle.launcher.exec.RunAsBuildOperationBuildActionRunner.run(RunAsBuildOperationBuildActionRunner.java:40)
    at org.gradle.tooling.internal.provider.SubscribableBuildActionRunner.run(SubscribableBuildActionRunner.java:51)
    at org.gradle.launcher.exec.InProcessBuildActionExecuter.execute(InProcessBuildActionExecuter.java:47)
    at org.gradle.launcher.exec.InProcessBuildActionExecuter.execute(InProcessBuildActionExecuter.java:30)
    at org.gradle.launcher.exec.BuildTreeScopeBuildActionExecuter.execute(BuildTreeScopeBuildActionExecuter.java:39)
    at org.gradle.launcher.exec.BuildTreeScopeBuildActionExecuter.execute(BuildTreeScopeBuildActionExecuter.java:25)
    at org.gradle.tooling.internal.provider.ContinuousBuildActionExecuter.execute(ContinuousBuildActionExecuter.java:80)
    at org.gradle.tooling.internal.provider.ContinuousBuildActionExecuter.execute(ContinuousBuildActionExecuter.java:53)
    at org.gradle.tooling.internal.provider.ServicesSetupBuildActionExecuter.execute(ServicesSetupBuildActionExecuter.java:57)
    at org.gradle.tooling.internal.provider.ServicesSetupBuildActionExecuter.execute(ServicesSetupBuildActionExecuter.java:32)
    at org.gradle.tooling.internal.provider.GradleThreadBuildActionExecuter.execute(GradleThreadBuildActionExecuter.java:36)
    at org.gradle.tooling.internal.provider.GradleThreadBuildActionExecuter.execute(GradleThreadBuildActionExecuter.java:25)
    at org.gradle.tooling.internal.provider.ParallelismConfigurationBuildActionExecuter.execute(ParallelismConfigurationBuildActionExecuter.java:43)
    at org.gradle.tooling.internal.provider.ParallelismConfigurationBuildActionExecuter.execute(ParallelismConfigurationBuildActionExecuter.java:29)
    at org.gradle.tooling.internal.provider.StartParamsValidatingActionExecuter.execute(StartParamsValidatingActionExecuter.java:64)
    at org.gradle.tooling.internal.provider.StartParamsValidatingActionExecuter.execute(StartParamsValidatingActionExecuter.java:29)
    at org.gradle.tooling.internal.provider.SessionFailureReportingActionExecuter.execute(SessionFailureReportingActionExecuter.java:59)
    at org.gradle.tooling.internal.provider.SessionFailureReportingActionExecuter.execute(SessionFailureReportingActionExecuter.java:44)
    at org.gradle.tooling.internal.provider.SetupLoggingActionExecuter.execute(SetupLoggingActionExecuter.java:45)
    at org.gradle.tooling.internal.provider.SetupLoggingActionExecuter.execute(SetupLoggingActionExecuter.java:30)
    at org.gradle.launcher.daemon.server.exec.ExecuteBuild.doBuild(ExecuteBuild.java:67)
    at org.gradle.launcher.daemon.server.exec.BuildCommandOnly.execute(BuildCommandOnly.java:36)
    at org.gradle.launcher.daemon.server.api.DaemonCommandExecution.proceed(DaemonCommandExecution.java:120)
    at org.gradle.launcher.daemon.server.exec.WatchForDisconnection.execute(WatchForDisconnection.java:37)
    at org.gradle.launcher.daemon.server.api.DaemonCommandExecution.proceed(DaemonCommandExecution.java:120)
    at org.gradle.launcher.daemon.server.exec.ResetDeprecationLogger.execute(ResetDeprecationLogger.java:26)
    at org.gradle.launcher.daemon.server.api.DaemonCommandExecution.proceed(DaemonCommandExecution.java:120)
    at org.gradle.launcher.daemon.server.exec.RequestStopIfSingleUsedDaemon.execute(RequestStopIfSingleUsedDaemon.java:34)
    at org.gradle.launcher.daemon.server.api.DaemonCommandExecution.proceed(DaemonCommandExecution.java:120)
    at org.gradle.launcher.daemon.server.exec.ForwardClientInput$2.call(ForwardClientInput.java:74)
    at org.gradle.launcher.daemon.server.exec.ForwardClientInput$2.call(ForwardClientInput.java:72)
    at org.gradle.util.Swapper.swap(Swapper.java:38)
    at org.gradle.launcher.daemon.server.exec.ForwardClientInput.execute(ForwardClientInput.java:72)
    at org.gradle.launcher.daemon.server.api.DaemonCommandExecution.proceed(DaemonCommandExecution.java:120)
    at org.gradle.launcher.daemon.server.exec.LogAndCheckHealth.execute(LogAndCheckHealth.java:55)
    at org.gradle.launcher.daemon.server.api.DaemonCommandExecution.proceed(DaemonCommandExecution.java:120)
    at org.gradle.launcher.daemon.server.exec.LogToClient.doBuild(LogToClient.java:62)
    at org.gradle.launcher.daemon.server.exec.BuildCommandOnly.execute(BuildCommandOnly.java:36)
    at org.gradle.launcher.daemon.server.api.DaemonCommandExecution.proceed(DaemonCommandExecution.java:120)
    at org.gradle.launcher.daemon.server.exec.EstablishBuildEnvironment.doBuild(EstablishBuildEnvironment.java:82)
    at org.gradle.launcher.daemon.server.exec.BuildCommandOnly.execute(BuildCommandOnly.java:36)
    at org.gradle.launcher.daemon.server.api.DaemonCommandExecution.proceed(DaemonCommandExecution.java:120)
    at org.gradle.launcher.daemon.server.exec.StartBuildOrRespondWithBusy$1.run(StartBuildOrRespondWithBusy.java:50)
    at org.gradle.launcher.daemon.server.DaemonStateCoordinator$1.run(DaemonStateCoordinator.java:295)
    at org.gradle.internal.concurrent.ExecutorPolicy$CatchAndRecordFailures.onExecute(ExecutorPolicy.java:63)
    at org.gradle.internal.concurrent.ManagedExecutorImpl$1.run(ManagedExecutorImpl.java:46)
    at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1167)
    at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:641)
    at org.gradle.internal.concurrent.ThreadFactoryImpl$ManagedThreadRunnable.run(ThreadFactoryImpl.java:55)
    at java.base/java.lang.Thread.run(Thread.java:844)

编译时我得到以下stacktrace：

List.nil()

当我用public void incl(int x) { Assert.check(currentState != BitsState.UNKNOWN); Assert.check(x >= 0); // <-- this line sizeTo((x >>> wordshift) + 1); bits[x >>> wordshift] = bits[x >>> wordshift] | (1 << (x & wordmask)); currentState = BitsState.NORMAL; } 替换参数时，此代码编译完美，这就是为什么我认为问题与参数有关。

以下代码抛出了异常：

visitMethodDef

Flow被调用（来自//important part in method visitMethodDef for (List<JCVariableDecl> l = tree.params; l.nonEmpty(); l = l.tail) { JCVariableDecl def = l.head; scan(def); Assert.check((def.sym.flags() & PARAMETER) != 0, "Method parameter without PARAMETER flag"); /* If we are executing the code from Gen, then there can be * synthetic or mandated variables, ignore them. */ initParam(def); } 类）：

initParam

调用protected void initParam(JCVariableDecl def) { inits.incl(def.sym.adr); uninits.excl(def.sym.adr); } ：

sym.adr

因此，如果我理解正确，参数的Symbol是＆lt; 0.手动创建adr并将MethodDecl#toString字段设置为大于0的值不起作用。

生成的代码（public static java.lang.String test(java.lang.String arg) { System.out.println("Running test method!"); return new java.lang.String("Hello!"); } ）有效：

java.lang.AssertionError

总结一下：在使用参数编译生成的方法时抛出nodelist = doc.getElementsByTagName("TwilioToken"); ，我不确定如何修复它。

6 个答案:

答案 0 :(得分：4)

我设法通过创建一个MethodSymbol获取生成的函数参数，使用TreeMaker :: MethodDef（MethodSymbol，JCTree.JCBlock）创建一个新的JCTree.JCMethodDecl，并迭代参数设置他们的adr为0（这是被接受的，@ Piotr Wilkin提到的规范中没有任何内容让我相信这不应该是有效的。）

// maker is a TreeMaker instance
// sym is a Symbol.MethodSymbol instance
// body is a JCTree.JCBlock instance
JCTree.JCMethodDecl decl = maker.MethodDef(sym, body);
decl.params.forEach(p -> {
    p.sym.adr = 0;
});

我认为这是有效的原因，因为javac不会尝试创建新符号（因为已经存在），而VarSymbols（JCTree.JCVariableDecl的sym字段）是可变的。此外，搜索javac代码几乎没有尝试覆盖它。

答案 1 :(得分：3)

实际上，Symbol类的JavaDoc会告诉您adr字段的用途：

The variable's address. Used for different purposes during flow analysis, translation and code generation. Flow analysis: If this is a blank final or local variable, its sequence number. Translation: If this is a private field, its access number. Code generation: If this is a local variable, its logical slot number.

它的默认值是-1，它基本上是null的基本类型，因此您在语义上（虽然不是技术上）获得NullPointerException。您需要根据上述文档填写参数位置（也可能是一些逆向工程，因为您正在使用内部API）。

答案 2 :(得分：1)

上述解决方案无法解决我的问题。

要解决此问题，我们需要使用 TreeMaker.Param（），而不是 TreeMaker.VarDef（）。 这是对我有帮助的解决方案：

错误的解决方案： 

return treeMaker.MethodDef(
            modifiers,
            elementUtils.getName(methodName),
            treeMaker.Type(new Type.JCVoidType()),
            List.nil(),
            List.of(treeMaker.VarDef(treeMaker.Modifiers(0), paramName, treeMaker.Type(type), null)),
            List.nil(),
            body,
            null
    );

工作解决方案： 

return treeMaker.MethodDef(
                modifiers,
                elementUtils.getName(methodName),
                treeMaker.Type(new Type.JCVoidType()),
                List.nil(),
                List.of(treeMaker.Param(paramName, type, null)),
                List.nil(),
                body,
                null
        );

答案 3 :(得分：1)

我遵循了@fashare2015 的想法。这是我的代码

public static JCTree.JCMethodDecl createSetMethod(JCTree.JCVariableDecl field) {
    JCTree.JCFieldAccess thisX = TreeMaker.Select(TreeMaker.Ident(NameApi.fromString("this")), field.name);
    JCTree.JCAssign assign = TreeMaker.Assign(thisX, TreeMaker.Ident(field.name));
    JCTree.JCExpression methodType = TreeMaker.Type(new Type.JCVoidType());
    JCTree.JCBlock methodBody = TreeMaker.Block(0, List.of(TreeMaker.Exec(assign)));
    Name methodName = NameApi.fromString(StringUtils.generateMethodName("set", field.getName().toString()));
    JCTree.JCVariableDecl param = TreeMaker.VarDef(TreeMaker.Modifiers(Flags.PARAMETER), field.name, field.vartype, null);
    param.pos = field.pos; // <---- This lines I used
    
    return TreeMaker.MethodDef(TreeMaker.Modifiers(Flags.PUBLIC), methodName, methodType,
            List.nil(), List.of(param), List.nil(), methodBody, null);
}

我使用 JDK 版本 14。

你可以在这里拉我的演示：link

答案 4 :(得分：0)

阅读javac的源代码后，我终于找到了解决方法。

关键是sym.adr的值为-1，然后将其由newVar()分配：

// Flow$AssignAnalyzer
void newVar(JCVariableDecl varDecl) {
    ...
    sym.adr = nextadr;
}

但是只有newVar()是visitVarDef()时，tree.sym才被trackable调用：

// Flow$AssignAnalyzer
public void visitVarDef(JCVariableDecl tree) {
    ...
    boolean track = trackable(tree.sym);
    if (track && tree.sym.owner.kind == MTH) {
        newVar(tree);
    }
    ...
}
// Flow$AssignAnalyzer
protected boolean trackable(VarSymbol sym) {
    return
        sym.pos >= startPos &&
        ((sym.owner.kind == MTH ||
        isFinalUninitializedField(sym)));
}

因此，我们在生成方法时应确保sym.pos >= startPos为真。

最后，我们应该像这样调用TreeMaker.pos之前仔细设置TreeMaker.MethodDef()：

// ensure the current pos is valid
treeMaker.at(jcClassDecl.pos);

treeMaker.MethodDef(...);

答案 5 :(得分：0)

我找到了解决办法：

在执行create getter方法之前，添加以下代码：

treeMaker.pos = jcVariableDecl.pos;

例如：

//add this code ，redefine the position of parameters in the syntax tree:

treeMaker.pos = jcVariableDecl.pos;

treeMaker.MethodDef(treeMaker.Modifiers(Flags.PUBLIC),
        getNewMethodName(jcVariableDecl.getName(), "set"),
        methodType,
        List.nil(),
        parameters,
        List.nil(),
        block,
        null);
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