RFR: 8286562: GCC 12 reports some compiler warnings [v9]

[Yasumasa Suenaga]

On Thu, 26 May 2022 03:48:31 GMT, Kim Barrett <kbarrett at openjdk.org> wrote:

>> Yasumasa Suenaga has updated the pull request incrementally with two additional commits since the last revision:
>> 
>>  - Change Array::data() implementation
>>  - Avoid stringop-overflow warning in jfrTraceIdBits.inline.hpp
>
> src/java.base/unix/native/libjli/java_md_common.c line 133:
> 
>> 131: 
>> 132:     snprintf_result = JLI_Snprintf(name, sizeof(name), "%s%c%s", indir, FILE_SEPARATOR, cmd);
>> 133:     if ((snprintf_result < 0) && (snprintf_result >= (int)sizeof(name))) {
> 
> That should be `||` rather than `&&`.

Good catch! I fixed it in new commit.

> src/java.base/unix/native/libjli/java_md_common.c line 135:
> 
>> 133:     if ((snprintf_result < 0) && (snprintf_result >= (int)sizeof(name))) {
>> 134:       return 0;
>> 135:     }
> 
> Pre-existing: It seems odd that this returns `0` above and below, rather than returning `NULL`.  I think there are one or two other places in this file that are similarly using literal `0` for a null pointer, though others are using `NULL`.  Something to report and clean up separately from this change.

I was wondering about that too.
I use `NULL` at L134, and have filed it as [JDK-8287363](https://bugs.openjdk.java.net/browse/JDK-8287363). I will work for it after this issue.

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PR: https://git.openjdk.java.net/jdk/pull/8646