RFR: 8352533: Report useful IOExceptions when jspawnhelper fails [v4]

[Aleksey Shipilev]

On Tue, 6 May 2025 10:56:54 GMT, Thomas Stuefe <stuefe at openjdk.org> wrote:

>> Aleksey Shipilev 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 six additional commits since the last revision:
>> 
>>  - Add bug ID
>>  - Merge branch 'master' into JDK-8352533-jspawnhelper-ioexceptions
>>  - Pull message into a field
>>  - Test cases
>>  - Merge branch 'master' into JDK-8352533-jspawnhelper-ioexceptions
>>  - Initial fix
>>    
>>    Good spawnhelper failure message
>>    
>>    Trying tests
>>    
>>    Print helper message on all IOExceptions
>>    
>>    Final
>
> src/java.base/unix/native/libjava/ProcessImpl_md.c line 348:
> 
>> 346:     }
>> 347:     /* ASCII Decimal representation uses 2.4 times as many bits as binary. */
>> 348:     fmtsize = sizeof(IOE_FORMAT) + strlen(internalErrorDetail) + strlen(detail) + 3 * sizeof(errnum);
> 
> Suggestion:
> 
>     fmtsize = sizeof(IOE_FORMAT) + 3 * sizeof(errnum) + strlen(detail) +  strlen(internalErrorDetail) + 1;
> 
> ... just to appease my OCD.

Right. Will be done in new commit.

> src/java.base/unix/native/libjava/ProcessImpl_md.c line 351:
> 
>> 349:     errmsg = NEW(char, fmtsize);
>> 350:     if (errmsg == NULL)
>> 351:         return;
> 
> Preexisting: seems to be weird to just quietly swallow the allocation error.

Yes. I am guessing the allocation error here means we are likely unable to allocate the `IOException` later on. History shows this check was added by JDK-8008118 -- and it looks only to please the static analysis tools. So I left this unchanged.

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PR Review Comment: https://git.openjdk.org/jdk/pull/24149#discussion_r2086340557
PR Review Comment: https://git.openjdk.org/jdk/pull/24149#discussion_r2086340234