RFR: 8369187: Add wrapper for <new> that forbids use of global allocation and deallocation functions [v3]

[Matthias Baesken]

On Sun, 16 Nov 2025 01:10:40 GMT, Kim Barrett <kbarrett at openjdk.org> wrote:

>> 8369187: Add wrapper for <new> that forbids use of global allocation and deallocation functions
>> 
>> Please review this change that adds `cppstdlib/new.hpp` as a wrapper for
>> including `<new>`. All existing inclusions of `<new>` are changed to include
>> the new wrapper.
>> 
>> In additional to including `<new>`, this wrapper also provides deprecation
>> declarations to prevent the use of some facilities by HotSpot code.
>> 
>> However, those deprecations need to be conditionalized to not apply to gtests,
>> so this change also adds a macro definition provided by the build system for
>> use in detecting that a header is being included by a gtest.
>> 
>> Testing: mach5 tier1
>
> Kim Barrett has updated the pull request with a new target base due to a merge or a rebase. The pull request now contains five commits:
> 
>  - Merge branch 'master' into wrap-stdlib-new
>  - poison implicit alloc/dealloc in globalDefinitions
>  - Merge branch 'master' into wrap-stdlib-new
>  - further conditionalize deprecation of hardare interference sizes
>  - add wrapper for <new>

When experimenting with the link time gc  OpenJDK configure option , I notice that the 2  symbols hardware_destructive_interference_size  /  fgrep hardware_constructive_interference_size  are eliminated more then 2000 (!) times from the objects of libjvm  (I enabled verbose priting to see what is eliminated)

fgrep hardware_destructive_interference_size  build.log | wc -l
2681
fgrep hardware_constructive_interference_size  build.log | wc -l
2681


With default settings (no linktime gc)  I see the symbol now in HS (fortunately only 2 times , not 2000+)


strings /linuxx86_64/jdk-opt/images/jdk/lib/server/libjvm.so | grep hardware_constructive_interference_size
_ZSt39hardware_constructive_interference_size
_ZSt39hardware_constructive_interference_size


Was this intended to got into libjvm.so ?

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PR Comment: https://git.openjdk.org/jdk/pull/28250#issuecomment-3760241677