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  1. JDK
  2. JDK-8220041

NullPointerException at jdk.compiler/com.sun.tools.javac.jvm.Code.emitop0

    Details

    • Subcomponent:
    • Resolved In Build:
      b30
    • CPU:
      x86_64
    • OS:
      generic

      Backports

        Description

        A DESCRIPTION OF THE PROBLEM :
        JDK 12 Compiler throws a NullPointerException, while compiling the following code:

        public class LocalVarAndBreakStmtsWithSwitch {

            public Runnable greetings(AgeGroup age) {

                Runnable thread = switch (age) {
                    case KIDS -> () -> System.out.println("Hi!");
                    case TEENS -> {
                        String greetingsFromDB = "";// load value from database
                        // some other complex/ simple processing here
                        break (() -> System.out.println(greetingsFromDB));
                    }
                    default -> () -> System.out.println("Doesn't matter");
                };

                return thread;
            }
            enum AgeGroup {KIDS, TEENS, ADULTS};
        }

        REGRESSION : Last worked in version 12

        STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
        Create a Java class with the following contents:

        public class LocalVarAndBreakStmtsWithSwitch {

            public Runnable greetings(AgeGroup age) {

                Runnable thread = switch (age) {
                    case KIDS -> () -> System.out.println("Hi!");
                    case TEENS -> {
                        String greetingsFromDB = "";// load value from database
                        // some other complex/ simple processing here
                        break (() -> System.out.println(greetingsFromDB));
                    }
                    default -> () -> System.out.println("Doesn't matter");
                };

                return thread;
            }
            enum AgeGroup {KIDS, TEENS, ADULTS};
        }

        EXPECTED VERSUS ACTUAL BEHAVIOR :
        EXPECTED -
        Successful compilation of the class, as per the documentation of switch expressions.
        ACTUAL -
        > javac --release 12 --enable-preview LocalVarAndBreakStmtsWithSwitch.java

        Note: LocalVarAndBreakStmtsWithSwitch.java uses preview language features.
        Note: Recompile with -Xlint:preview for details.
        An exception has occurred in the compiler (12). 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.NullPointerException
                at jdk.compiler/com.sun.tools.javac.jvm.Code.emitop0(Code.java:567)
                at jdk.compiler/com.sun.tools.javac.jvm.Items$LocalItem.load(Items.java:397)
                at jdk.compiler/com.sun.tools.javac.jvm.Gen.genArgs(Gen.java:872)
                at jdk.compiler/com.sun.tools.javac.jvm.Gen.visitApply(Gen.java:1808)
                at jdk.compiler/com.sun.tools.javac.tree.JCTree$JCMethodInvocation.accept(JCTree.java:1709)
                at jdk.compiler/com.sun.tools.javac.jvm.Gen.genExpr(Gen.java:853)
                at jdk.compiler/com.sun.tools.javac.jvm.Gen.visitExec(Gen.java:1702)
                at jdk.compiler/com.sun.tools.javac.tree.JCTree$JCExpressionStatement.accept(JCTree.java:1519)
                at jdk.compiler/com.sun.tools.javac.jvm.Gen.genDef(Gen.java:595)
                at jdk.compiler/com.sun.tools.javac.jvm.Gen.genStat(Gen.java:630)
                at jdk.compiler/com.sun.tools.javac.jvm.Gen.genStat(Gen.java:616)
                at jdk.compiler/com.sun.tools.javac.jvm.Gen.genStats(Gen.java:667)
                at jdk.compiler/com.sun.tools.javac.jvm.Gen.visitBlock(Gen.java:1067)
                at jdk.compiler/com.sun.tools.javac.tree.JCTree$JCBlock.accept(JCTree.java:1026)
                at jdk.compiler/com.sun.tools.javac.jvm.Gen.genDef(Gen.java:595)
                at jdk.compiler/com.sun.tools.javac.jvm.Gen.genStat(Gen.java:630)
                at jdk.compiler/com.sun.tools.javac.jvm.Gen.genMethod(Gen.java:937)
               at jdk.compiler/com.sun.tools.javac.jvm.Gen.visitMethodDef(Gen.java:900)
                at jdk.compiler/com.sun.tools.javac.tree.JCTree$JCMethodDecl.accept(JCTree.java:872)
                at jdk.compiler/com.sun.tools.javac.jvm.Gen.genDef(Gen.java:595)
                at jdk.compiler/com.sun.tools.javac.jvm.Gen.genClass(Gen.java:2345)
                at jdk.compiler/com.sun.tools.javac.main.JavaCompiler.genCode(JavaCompiler.java:756)
                at jdk.compiler/com.sun.tools.javac.main.JavaCompiler.generate(JavaCompiler.java:1635)
                at jdk.compiler/com.sun.tools.javac.main.JavaCompiler.generate(JavaCompiler.java:1603)
                at jdk.compiler/com.sun.tools.javac.main.JavaCompiler.compile(JavaCompiler.java:973)
                at jdk.compiler/com.sun.tools.javac.main.Main.compile(Main.java:311)
                at jdk.compiler/com.sun.tools.javac.main.Main.compile(Main.java:170)
                at jdk.compiler/com.sun.tools.javac.Main.compile(Main.java:57)
                at jdk.compiler/com.sun.tools.javac.Main.main(Main.java:43)

        ---------- BEGIN SOURCE ----------
        Test case not required - the source doesn't compile. NullPointerException is thrown by JDK 12 compiler.
        ---------- END SOURCE ----------

        FREQUENCY : always


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                • Assignee:
                  jlahoda Jan Lahoda
                  Reporter:
                  webbuggrp Webbug Group
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                  • Created:
                    Updated:
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