RFR: 8328536: javac - crash on unknown type referenced in yield statement

[Chen Liang]

On Tue, 19 Mar 2024 17:49:32 GMT, Hannes Greule <hgreule at openjdk.org> wrote:

> Pasting  e.g.
> 
> I m(I i, int x) {
>    return switch (x) {
>         default -> i;
>    };
> }
> 
> in jshell will cause a crash if `I` is not declared already. This comes down to javac not creating an error type for the value of the (implicit) yield from the switch.
> 
> Javac will not crash but swallow the exception, and create a file containing the command line options.
> 
> I first thought about just checking for null of the type here https://github.com/openjdk/jdk/blob/9ca4ae3d3b746f1d75036d189ff98f02b73b948f/src/jdk.compiler/share/classes/com/sun/tools/javac/comp/Attr.java#L1640 but after a closer look, the `checkIdInternal` method seems a better fit, as it also updates the type normally.

test/langtools/jdk/jshell/ToolSimpleTest.java line 1:

> 1: /*

You should add the bug id in the test header.

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PR Review Comment: https://git.openjdk.org/jdk/pull/18383#discussion_r1542127628