On Tue, 1 Jul 2025 12:25:04 GMT, Anton Artemov <d...@openjdk.org> wrote:
> Hi, please consider the following changes:
>
> this PR addresses the issue of stringop-overflow warnings produced by GCC.
> The compiler does think that the thread pointer returned by
> `JavaThread::current()` can be null, though it cant. The thread pointer ends
> up being an argument in `__atomic_load`, and the compiler reports the warning
> related to argument of that method.
>
> The patch adds a hint to the compiler by means of `__builtin_unreachable()`
> intrinsic, which tells the compiler that certain piece of code will never be
> reached (case of thread pointer being null). This solves the issue.
>
> Tested in tiers 1-3 and GHA.
src/hotspot/share/jvmci/jvmciCodeInstaller.cpp line 929:
> 927: if (thread == nullptr) {
> 928: // This is to prevent --stringop-overflow warning from GCC on
> linux/fastdebug.
> 929: // GCC does believe that JavaThread::current() can return nullptr,
`does believe` -> `believes`
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PR Review Comment: https://git.openjdk.org/jdk/pull/26067#discussion_r2179510064
