RFR: 8314275: Incorrect stepping in switch [v2]

[Vicente Romero]

On Thu, 8 Feb 2024 14:57:16 GMT, Aggelos Biboudis <abimpoudis at openjdk.org> wrote:

>> In code like the one below, the observable effect was that if the user debugs the following method, `multiply` called with `1`, the debugger steps from line 4 to line 6 (instead of 7) giving the impression that line 6 is going to be executed. The reason is that the `LineNumberTable` did not include an entry at the end of the `switch` mapping the statement that follows, to bytecode.
>> 
>> 
>> 1 private static double multiply(Integer i) { 
>> 2   double cr = 15;                              
>> 3    cr = switch (i) {                            
>> 4        case 1 -> cr * 1;                       
>> 5        case 2 -> cr * 2;                      
>> 6        default -> cr * 4;                     
>> 7    };                                           
>> 8    return cr;                              
>> 9 }
>
> Aggelos Biboudis has updated the pull request with a new target base due to a merge or a rebase. The incremental webrev excludes the unrelated changes brought in by the merge/rebase. The pull request contains two additional commits since the last revision:
> 
>  - Merge branch 'master' into fix-#8314275
>  - 8314275: Incorrect stepping in switch

looks good, just a minor comment

src/jdk.compiler/share/classes/com/sun/tools/javac/jvm/Gen.java line 1433:

> 1431: 
> 1432:             // Emit line position for the end of the switch
> 1433:             code.statBegin(TreeInfo.endPos(swtch));

shouldn't this change affect already existing tests like: RuleSwitchBreaks.java in the same folder: test/langtools/tools/javac/classfiles/attributes/LineNumberTable/?

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Marked as reviewed by vromero (Reviewer).

PR Review: https://git.openjdk.org/jdk/pull/17772#pullrequestreview-1870690309
PR Review Comment: https://git.openjdk.org/jdk/pull/17772#discussion_r1483253681