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https://issues.apache.org/jira/browse/GROOVY-9424?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17051912#comment-17051912
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Vaidotas Valuckas edited comment on GROOVY-9424 at 3/5/20, 8:52 AM:
--------------------------------------------------------------------
It looks like this change
[https://github.com/apache/groovy/commit/cd2b0e42fcf418e16776f34a66ed5cacc7711630#diff-3557aa86d96d4931ca9f64e88bd5f85fR480]
introduced a regression in compiling switch statements with clauses containing
only a break.
A simple reproducer:
{code:java}
int i = 42
switch(i) {
case 1:
break
case 2:
println 2
}
{code}
This yields the following with the latest Groovy 2.5.10-SNAPSHOT:
{code:java}
java.lang.ClassCastException: class
org.codehaus.groovy.ast.stmt.ReturnStatement cannot be cast to class
org.codehaus.groovy.ast.stmt.BlockStatement (org.codehaus.groovy
.ast.stmt.ReturnStatement and org.codehaus.groovy.ast.stmt.BlockStatement are
in unnamed module of loader
org.gradle.internal.classloader.VisitableURLClassLoader @135490 40) at
org.codehaus.groovy.classgen.FinalVariableAnalyzer.fallsThrough(FinalVariableAnalyzer.java:480)
{code}
Adding anything between the first case and break makes it compile again:
{code:java}
int i = 42
switch(i) {
case 1:
true
break
case 2:
println 2
}
{code}
was (Author: rieske):
It looks like this change
[https://github.com/apache/groovy/commit/cd2b0e42fcf418e16776f34a66ed5cacc7711630#diff-3557aa86d96d4931ca9f64e88bd5f85fR480]
introduced a regression in compiling switch statements with clauses containing
only a break.
A simple reproducer:
{code:java}
int i = 42
switch(i) {
case 1:
break
case 2:
println 2
}
{code}
This yields the following with the latest Groovy 2.5.10-SNAPSHOT:
{code:java}
java.lang.ClassCastException: class
org.codehaus.groovy.ast.stmt.ReturnStatement cannot be cast to class
org.codehaus.groovy.ast.stmt.BlockStatement (org.codehaus.groovy
.ast.stmt.ReturnStatement and org.codehaus.groovy.ast.stmt.BlockStatement are
in unnamed module of loader
org.gradle.internal.classloader.VisitableURLClassLoader @135490 40) at
org.codehaus.groovy.classgen.FinalVariableAnalyzer.fallsThrough(FinalVariableAnalyzer.java:480)
{code}
Adding anything between the first case and break makes it compile again:
{code:java}
int i = 42
switch(i) {
case 1:
true
break
case 2:
println 2
}
{code}
> Incorrect handling of final variables within switch
> ---------------------------------------------------
>
> Key: GROOVY-9424
> URL: https://issues.apache.org/jira/browse/GROOVY-9424
> Project: Groovy
> Issue Type: Bug
> Reporter: Daniel Wilmer
> Assignee: Paul King
> Priority: Major
> Fix For: 2.5.10, 3.0.2
>
> Time Spent: 0.5h
> Remaining Estimate: 0h
>
> The following code runs on groovy 2.4.18 but not on groovy 3.0.1.
> {code}
> static void main(String[] args) {
> final String result
> switch (2) {
> case 1: result = "a"; break;
> case 2: result = "b"; break;
> default: result = "x"
> }
> println result
> }
> {code}
> *Error: Groovyc: The variable [result] is declared final but is reassigned.*
> Since we use final in our codebase a lot (although it seems to be ignored by
> groovy 2.4),
> we will have to adjust a lot of places to make our code groovy 3.0 compatible.
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