Bug ID: JDK-8338236 Compile error in cgroup code on Linux when using clang

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JDK 21	JDK 24
21.0.9Fixed	24 b11Fixed

When building with
Ubuntu clang version 14.0.0-1ubuntu1.1

we run into the following compile error  (seen on Linux ppc64le, probably also an error on x86_64) :

/jdk/src/hotspot/os/linux/cgroupV1Subsystem_linux.hpp:65:10: error: 'is_read_only' overrides a member function but is not marked 'override' [-Werror,-Winconsistent-missing-override]
    bool is_read_only() { return _read_only; }
         ^
/jdk/src/hotspot/os/linux/cgroupSubsystem_linux.hpp:108:18: note: overridden virtual function is here
    virtual bool is_read_only() = 0;
                 ^
In file included from /jdk/src/hotspot/os/linux/cgroupSubsystem_linux.cpp:30:
/jdk/src/hotspot/os/linux/cgroupV2Subsystem_linux.hpp:131:54: error: 'memory_controller' overrides a member function but is not marked 'override' [-Werror,-Winconsistent-missing-override]
    CachingCgroupController<CgroupMemoryController>* memory_controller() { return _memory; }
                                                     ^
/jdk/src/hotspot/os/linux/cgroupSubsystem_linux.hpp:235:62: note: overridden virtual function is here
    virtual CachingCgroupController<CgroupMemoryController>* memory_controller() = 0;

A pull request was submitted for review. Branch: master URL: https://git.openjdk.org/jdk21u-dev/pull/1663 Date: 2025-04-16 10:55:45 +0000
01-07-2025
Fix request (21u) - but only for the October release I'd like to port JDK-8338236 to 21u as discussed in: [21u] Backport intention of 8322420: [Linux] cgroup v2: Limits in parent nested control groups are not detected https://mail.openjdk.org/pipermail/jdk-updates-dev/2025-March/042592.html This is a PR 5 of 6 in this series, it has a patch dependency on PR of JDK-8331560. This backport is clean.
17-04-2025
A pull request was submitted for review. Branch: master URL: https://git.openjdk.org/jdk21u-dev/pull/1652 Date: 2025-04-15 13:28:03 +0000
15-04-2025
> Perhaps the warning-enabled-by-default is only true for some more restricted cases, like having a pure virtual with a derived class not annotating the function as either virtual or override According to https://stackoverflow.com/questions/29145476/requiring-virtual-function-overrides-to-use-override-keyword and https://reviews.llvm.org/D82728 "Clang already has -Winconsistent-missing-override, which only warns in the case where there is at least one function already marked override in a class. " the inconsistent-missing-override warning is indeed less "aggressive".
14-08-2024
I'm astonished that these are the only such warnings. Perhaps the warning-enabled-by-default is only true for some more restricted cases, like having a pure virtual with a derived class not annotating the function as either virtual or override?
14-08-2024
The "xyz overrides a member function but is not marked 'override' " warning can be seen both with clang14 (Linux) and clang15 (macOS), even without setting additional warning flags.
14-08-2024
Changeset: 38bd8a36 Branch: master Author: Matthias Baesken <mbaesken@openjdk.org> Date: 2024-08-14 09:52:23 +0000 URL: https://git.openjdk.org/jdk/commit/38bd8a36704a962f0ad1052fd2ec150a61663256
14-08-2024
[~kbarrett] should I try to disable the warning ?
14-08-2024
A pull request was submitted for review. Branch: master URL: https://git.openjdk.org/jdk/pull/20562 Date: 2024-08-13 07:59:11 +0000
13-08-2024

Causes :	JDK-8331560 - Refactor Hotspot container detection code so that subsystem delegates to controllers
Relates :	JDK-8341644 - Compile error in cgroup coding when using toolchain clang