RFR: 8291917: Windows - Dump error diagnostics when runtime libraries fail to load [v3]

[Julian Waters]

On Sat, 6 Aug 2022 11:36:44 GMT, Thomas Stuefe <stuefe at openjdk.org> wrote:

>> The only non Windows code that uses the `DLL_ERROR4` macro is Unix's java_md_common.c, where it reports the same `JVM_FindClassFromBootLoader` issue that Windows also does, and the shared args.c when a file cannot be found by path:
>> 
>> static JLI_List expandArgFile(const char *arg) {
>>     JLI_List rv;
>>     struct stat st;
>>     FILE *fptr = fopen(arg, "r");
>> 
>>     /* arg file cannot be opened */
>>     if (fptr == NULL || fstat(fileno(fptr), &st) != 0) {
>>         JLI_ReportMessage(CFG_ERROR6, arg);
>>         exit(1);
>>     } else {
>>         if (st.st_size > MAX_ARGF_SIZE) {
>>             JLI_ReportMessage(CFG_ERROR10, MAX_ARGF_SIZE);
>>             exit(1);
>>         }
>>     }
>> 
>>     rv = readArgFile(fptr);
>> 
>>     /* error occurred reading the file */
>>     if (rv == NULL) {
>>         JLI_ReportMessage(DLL_ERROR4, arg);
>>         exit(1);
>>     }
>>     fclose(fptr);
>> 
>>     return rv;
>> }
>> 
>> 
>> In any case, the only thing that would change would be "Error: loading:" to "Error: Failed to load" as the prefix of the message, which semantically is the same whatever the context may be, just a small change I thought that would look better whenever the macro is used
>
> You also have one use where the VM does a GetProcAddress on windows. "Failed to load" feels wrong for a failed dlsym. But "Error loading" is not much better either, I admit.
> 
> In general, the smaller and focused you keep changes, the easier they are to review and the better they are down-portable if that should be needed. I usually try to do aesthetic changes in separate RFEs. In this change, if you want to fix the display of additional diagnostic info, I'd just do that.

Agreed, will split this part into another RFE (initially didn't do this because such a change felt too trivial for an entire entry in the JBS), but I do feel like waiting for more opinions on what the prefix should be changed to before doing that

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PR: https://git.openjdk.org/jdk/pull/9749