RFR: JDK-8301072: Replace NULL with nullptr in share/oops/ [v2]

[David Holmes]

On Fri, 27 Jan 2023 13:42:43 GMT, Johan Sjölen <jsjolen at openjdk.org> wrote:

>> Hi, this PR changes all occurrences of NULL to nullptr for the subdirectory share/oops/. 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 incrementally with one additional commit since the last revision:
> 
>   Do stefank's fixes

Looks good. Thanks!

src/hotspot/share/oops/method.hpp line 794:

> 792: 
> 793:   // Use checked_resolve_jmethod_id() in situations where the caller
> 794:   // should provide a valid jmethodID, but might not. null is returned

Nit: Null (as it starts a sentence)

src/hotspot/share/oops/oop.hpp line 263:

> 261:   // Like "forward_to", but inserts the forwarding pointer atomically.
> 262:   // Exactly one thread succeeds in inserting the forwarding pointer, and
> 263:   // this call returns "null" for that thread; any other thread has the

Nit: null should not be in quotes

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

Marked as reviewed by dholmes (Reviewer).

PR: https://git.openjdk.org/jdk/pull/12186