RFR: 8337976: Insufficient error recovery in parser for switch inside class body

[Vicente Romero]

On Fri, 9 Aug 2024 14:57:21 GMT, Jan Lahoda <jlahoda at openjdk.org> wrote:

> Consider this code:
> 
> public class T9999999 {
>     switch (0) { default: }
> }
> 
> 
> When trying to compile this, javac crashes:
> 
> 
> $ .../jdk-22/bin/javac -XDdev /tmp/T9999999.java
> /tmp/T9999999.java:2: error: switch expression does not have any result expressions
>     switch (0) { default: } f;
>     ^
> 1 error
> An exception has occurred in the compiler (22.0.1-internal). Please file a bug against the Java compiler via the Java bug reporting page (https://bugreport.java.com/) after checking the Bug Database (https://bugs.java.com/) for duplicates. Include your program, the following diagnostic, and the parameters passed to the Java compiler in your report. Thank you.
> java.lang.AssertionError: Unexpected tree: switch (0) {
> default:
> 
> } with kind: SWITCH_EXPRESSION within: switch (0) {
> default:
> 
> } with kind: SWITCH_EXPRESSION
>         at jdk.compiler/com.sun.tools.javac.util.Assert.error(Assert.java:162)
>         at jdk.compiler/com.sun.tools.javac.comp.Attr$TypeAnnotationsValidator.validateAnnotatedType(Attr.java:5881)
>         at jdk.compiler/com.sun.tools.javac.comp.Attr$TypeAnnotationsValidator.visitVarDef(Attr.java:5727)
>         at jdk.compiler/com.sun.tools.javac.tree.JCTree$JCVariableDecl.accept(JCTree.java:1022)
>         at jdk.compiler/com.sun.tools.javac.tree.TreeScanner.scan(TreeScanner.java:50)
>         at jdk.compiler/com.sun.tools.javac.comp.Attr$TypeAnnotationsValidator.visitClassDef(Attr.java:5780)
>         at jdk.compiler/com.sun.tools.javac.tree.JCTree$JCClassDecl.accept(JCTree.java:814)
>         at jdk.compiler/com.sun.tools.javac.comp.Attr.validateTypeAnnotations(Attr.java:5677)
>         at jdk.compiler/com.sun.tools.javac.code.TypeAnnotations.lambda$validateTypeAnnotationsSignatures$1(TypeAnnotations.java:144)
>         at jdk.compiler/com.sun.tools.javac.comp.Annotate.flush(Annotate.java:200)
>         at jdk.compiler/com.sun.tools.javac.comp.Annotate.unblockAnnotations(Annotate.java:144)
>         at jdk.compiler/com.sun.tools.javac.comp.Annotate.enterDone(Annotate.java:157)
>         at jdk.compiler/com.sun.tools.javac.main.JavaCompiler.enterDone(JavaCompiler.java:1827)
>         at jdk.compiler/com.sun.tools.javac.main.JavaCompiler.enterTrees(JavaCompiler.java:1081)
>         at jdk.compiler/com.sun.tools.javac.main.JavaCompiler.compile(JavaCompiler.java:947)
>         at jdk.compiler/com.sun.tools.javac.main.Main.compile(Main.java:319)
>         at jdk.compiler/com.sun.tools.javac.main.Main.compile(Main.java:178)
>         at jdk.compiler/com.sun.tools.javac.Main.compile(...

src/jdk.compiler/share/classes/com/sun/tools/javac/parser/JavacParser.java line 4923:

> 4921:     private boolean isDefiniteStatementStartToken() {
> 4922:         return switch (token.kind) {
> 4923:             case IF, WHILE, DO, SWITCH, RETURN, TRY, FOR, ASSERT, BREAK,

should `yield`, `synchronized` be included?

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PR Review Comment: https://git.openjdk.org/jdk/pull/20526#discussion_r1711849240