java - 调试内部编译器错误 (Java) 以查找有问题的源代码

Question

由于 JDK 错误，我设法编写了一些在使用 JDK 1.8.0_131 编译期间导致错误的代码。我可以仅用几行代码重现该问题，但我找不到在我的项目中哪里使用了导致错误的模式。

我的目标是找出我项目中的哪些代码导致了这个错误，并应用解决方法。

发布与复制

JDK-8074381 bug report 中概述了该问题并且只需几行代码即可复制。

public class Test {
  public interface Foo<L> extends Function<Number, String> {
    String apply(Number p);
  }
  private static final Foo CRASH = p -> "This will crash javac 1.8.0_131";
}

当使用非参数化的 lambda 而不是非参数化的内部类(根据我认为的语言规范，这两者都应该有效)时，问题就会显现出来。所以

private static final Foo INNER = new Foo<Object>() {
  @Override
  public String apply(final Number p) {
    return "This will not crash javac 1.8.0_131";
  }
};

工作正常。有问题的堆栈跟踪开始(为了您的理智而被截断):

An exception has occurred in the compiler (1.8.0_131). 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 com.sun.tools.javac.util.Assert.error(Assert.java:126)
        at com.sun.tools.javac.util.Assert.check(Assert.java:45)
        at com.sun.tools.javac.code.Types.functionalInterfaceBridges(Types.java:659)
        at com.sun.tools.javac.comp.LambdaToMethod$LambdaAnalyzerPreprocessor$TranslationContext.<init>(LambdaToMethod.java:1770)
        at com.sun.tools.javac.comp.LambdaToMethod$LambdaAnalyzerPreprocessor$LambdaTranslationContext.<init>(LambdaToMethod.java:1853)
        at com.sun.tools.javac.comp.LambdaToMethod$LambdaAnalyzerPreprocessor.analyzeLambda(LambdaToMethod.java:1337)
        at com.sun.tools.javac.comp.LambdaToMethod$LambdaAnalyzerPreprocessor.visitLambda(LambdaToMethod.java:1322)
        at com.sun.tools.javac.tree.JCTree$JCLambda.accept(JCTree.java:1624)
        at com.sun.tools.javac.tree.TreeTranslator.translate(TreeTranslator.java:58)
        at com.sun.tools.javac.tree.TreeTranslator.visitVarDef(TreeTranslator.java:153)

识别

我知道 this issue is fixed in JDK9 ，但是这个项目要求我使用 JDK 8。

因此，与其更新到 JDK9，我还需要找出该项目中的哪些代码产生了错误。这是我尝试过的。

1. 我的第一个想法是检查发生此错误时正在编译的文件。但是，遇到错误时，我不知道如何检查正在编译哪个源文件。如果可能的话，这些信息会很有帮助。

2. 我的第二个想法是对我的所有 代码进行正则表达式搜索，以查找任何类型参数化接口(interface)或扩展通用接口(interface)的接口(interface)。这些搜索都没有产生明显匹配问题产生代码的代码——没有未使用的泛型(在示例中将 interface Foo<L> 更改为 interface Foo 将解决问题)。 因此，我认为对编译器内部实际导致此错误的原因有更深入的了解，可能有助于识别负责的代码段，因为它可能会扩大我的搜索标准。 (对于一个完全不同的问题，我也有可能得到一个具有完全相同堆栈跟踪的错误，但这对我来说似乎不太可能，我不确定我从哪里开始，有什么想法吗？)

我认为最值得的是能够检查编译器日志或其他东西来检查出现此问题时正在编译的内容。有什么想法吗？

谢谢。

Answer 1

我注意到错误报告有一个包含类信息的 .out 文件。第一个引用点是遵循 How to file a JDK Bug Report .

javac 命令有一个-verbose 选项。 我使用错误报告的类进行了尝试，它写了这个输出:

javac Lib.java -verbose
[parsing started RegularFileObject[Lib.java]]
[parsing completed 26ms]
[search path for source files: .]
[search path for class files: /Library/Java/JavaVirtualMachines/jdk1.8.0_92.jdk/Contents/Home/jre/lib/resources.jar,/Library/Java/JavaVirtualMachines/jdk1.8.0_92.jdk/Contents/Home/jre/lib/rt.jar,/Library/Java/JavaVirtualMachines/jdk1.8.0_92.jdk/Contents/Home/jre/lib/sunrsasign.jar,/Library/Java/JavaVirtualMachines/jdk1.8.0_92.jdk/Contents/Home/jre/lib/jsse.jar,/Library/Java/JavaVirtualMachines/jdk1.8.0_92.jdk/Contents/Home/jre/lib/jce.jar,/Library/Java/JavaVirtualMachines/jdk1.8.0_92.jdk/Contents/Home/jre/lib/charsets.jar,/Library/Java/JavaVirtualMachines/jdk1.8.0_92.jdk/Contents/Home/jre/lib/jfr.jar,/Library/Java/JavaVirtualMachines/jdk1.8.0_92.jdk/Contents/Home/jre/classes,/Library/Java/JavaVirtualMachines/jdk1.8.0_92.jdk/Contents/Home/jre/lib/ext/cldrdata.jar,/Library/Java/JavaVirtualMachines/jdk1.8.0_92.jdk/Contents/Home/jre/lib/ext/dnsns.jar,/Library/Java/JavaVirtualMachines/jdk1.8.0_92.jdk/Contents/Home/jre/lib/ext/jaccess.jar,/Library/Java/JavaVirtualMachines/jdk1.8.0_92.jdk/Contents/Home/jre/lib/ext/jfxrt.jar,/Library/Java/JavaVirtualMachines/jdk1.8.0_92.jdk/Contents/Home/jre/lib/ext/localedata.jar,/Library/Java/JavaVirtualMachines/jdk1.8.0_92.jdk/Contents/Home/jre/lib/ext/nashorn.jar,/Library/Java/JavaVirtualMachines/jdk1.8.0_92.jdk/Contents/Home/jre/lib/ext/sunec.jar,/Library/Java/JavaVirtualMachines/jdk1.8.0_92.jdk/Contents/Home/jre/lib/ext/sunjce_provider.jar,/Library/Java/JavaVirtualMachines/jdk1.8.0_92.jdk/Contents/Home/jre/lib/ext/sunpkcs11.jar,/Library/Java/JavaVirtualMachines/jdk1.8.0_92.jdk/Contents/Home/jre/lib/ext/zipfs.jar,/System/Library/Java/Extensions/AppleScriptEngine.jar,/System/Library/Java/Extensions/dns_sd.jar,/System/Library/Java/Extensions/j3daudio.jar,/System/Library/Java/Extensions/j3dcore.jar,/System/Library/Java/Extensions/j3dutils.jar,/System/Library/Java/Extensions/jai_codec.jar,/System/Library/Java/Extensions/jai_core.jar,/System/Library/Java/Extensions/mlibwrapper_jai.jar,/System/Library/Java/Extensions/MRJToolkit.jar,/System/Library/Java/Extensions/vecmath.jar,.]
[loading ZipFileIndexFileObject[/Library/Java/JavaVirtualMachines/jdk1.8.0_92.jdk/Contents/Home/lib/ct.sym(META-INF/sym/rt.jar/java/util/List.class)]]
[loading ZipFileIndexFileObject[/Library/Java/JavaVirtualMachines/jdk1.8.0_92.jdk/Contents/Home/lib/ct.sym(META-INF/sym/rt.jar/java/util/function/Predicate.class)]]
[loading ZipFileIndexFileObject[/Library/Java/JavaVirtualMachines/jdk1.8.0_92.jdk/Contents/Home/lib/ct.sym(META-INF/sym/rt.jar/java/lang/Object.class)]]
[loading ZipFileIndexFileObject[/Library/Java/JavaVirtualMachines/jdk1.8.0_92.jdk/Contents/Home/lib/ct.sym(META-INF/sym/rt.jar/java/lang/Class.class)]]
[loading ZipFileIndexFileObject[/Library/Java/JavaVirtualMachines/jdk1.8.0_92.jdk/Contents/Home/lib/ct.sym(META-INF/sym/rt.jar/java/lang/SuppressWarnings.class)]]
[loading ZipFileIndexFileObject[/Library/Java/JavaVirtualMachines/jdk1.8.0_92.jdk/Contents/Home/lib/ct.sym(META-INF/sym/rt.jar/java/lang/annotation/Annotation.class)]]
[loading ZipFileIndexFileObject[/Library/Java/JavaVirtualMachines/jdk1.8.0_92.jdk/Contents/Home/lib/ct.sym(META-INF/sym/rt.jar/java/lang/String.class)]]
[loading ZipFileIndexFileObject[/Library/Java/JavaVirtualMachines/jdk1.8.0_92.jdk/Contents/Home/lib/ct.sym(META-INF/sym/rt.jar/java/lang/annotation/Target.class)]]
[loading ZipFileIndexFileObject[/Library/Java/JavaVirtualMachines/jdk1.8.0_92.jdk/Contents/Home/lib/ct.sym(META-INF/sym/rt.jar/java/lang/annotation/ElementType.class)]]
[loading ZipFileIndexFileObject[/Library/Java/JavaVirtualMachines/jdk1.8.0_92.jdk/Contents/Home/lib/ct.sym(META-INF/sym/rt.jar/java/lang/annotation/Retention.class)]]
[loading ZipFileIndexFileObject[/Library/Java/JavaVirtualMachines/jdk1.8.0_92.jdk/Contents/Home/lib/ct.sym(META-INF/sym/rt.jar/java/lang/annotation/RetentionPolicy.class)]]
[checking Lib]
[loading ZipFileIndexFileObject[/Library/Java/JavaVirtualMachines/jdk1.8.0_92.jdk/Contents/Home/lib/ct.sym(META-INF/sym/rt.jar/java/io/Serializable.class)]]
[loading ZipFileIndexFileObject[/Library/Java/JavaVirtualMachines/jdk1.8.0_92.jdk/Contents/Home/lib/ct.sym(META-INF/sym/rt.jar/java/lang/AutoCloseable.class)]]
An exception has occurred in the compiler (1.8.0_92). 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

鉴于它打印出 Checking Lib 并且在编译时失败，这使它成为查找源文件的有用工具。所以你应该能够在详细模式下编译你的项目，并且它会在这个错误的第一个实例中失败(我认为)