RFR: JDK-8301493: Replace NULL with nullptr in cpu/aarch64 [v3]

[Thomas Schatzl]

On Tue, 11 Apr 2023 13:22:40 GMT, Johan Sjölen <jsjolen at openjdk.org> wrote:

>> Hi, this PR changes all occurrences of NULL to nullptr for the subdirectory cpu/aarch64. Unfortunately the script that does the change isn't perfect, and so we
>> need to comb through these manually to make sure nothing has gone wrong. I also review these changes but things slip past my eyes sometimes.
>> 
>> Here are some typical things to look out for:
>> 
>> 1. No changes but copyright header changed (probably because I reverted some changes but forgot the copyright).
>> 2. Macros having their NULL changed to nullptr, these are added to the script when I find them. They should be NULL.
>> 3. nullptr in comments and logs. We try to use lower case "null" in these cases as it reads better. An exception is made when code expressions are in a comment.
>> 
>> An example of this:
>> 
>> ```c++
>> // This function returns null
>> void* ret_null();
>> // This function returns true if *x == nullptr
>> bool is_nullptr(void** x);
>> 
>> 
>> Note how `nullptr` participates in a code expression here, we really are talking about the specific value `nullptr`.
>> 
>> Thanks!
>
> Johan Sjölen has updated the pull request with a new target base due to a merge or a rebase. The pull request now contains five commits:
> 
>  - Fix style
>  - Merge remote-tracking branch 'origin/master' into JDK-8301493
>  - Explicitly cast
>  - Fixes
>  -  Replace NULL with nullptr in cpu/aarch64

Remaining `NULL` in

gc/shared/BarrierSetAssembler::check_oop()
codeBuffer_aarch64.cpp/emit_shared_trampolines()
stubGenerator_aarch64.cpp/generate_final_stubs()
vm_version_aarch64.cpp/check_info_file()

-------------

Changes requested by tschatzl (Reviewer).

PR Review: https://git.openjdk.org/jdk/pull/12321#pullrequestreview-1410938066