unused and set but not used variable warnings when building with toolchain clang on Linux

[Magnus Ihse Bursie]

On 2024-10-07 16:45, Baesken, Matthias wrote:

> Hi, I came across  some warnings as errors today when trying to build 
>  on Linux with toolchain  clang     (clang 15 on USE Linux)  :
>
> jdk/src/jdk.jpackage/share/native/common/Log.cpp:46:28: error: unused 
> variable 'defaultLogLevel' [-Werror,-Wunused-const-variable]
>
>     const Logger::LogLevel defaultLogLevel = Logger::LOG_TRACE;
>
> jdk/src/jdk.hotspot.agent/linux/native/libsaproc/symtab.c:359:11: 
> error: variable 'rslt' set but not used 
> [-Werror,-Wunused-but-set-variable]
>
>       int rslt;
>
> Should we adjust the coding ?
>
I'd say this sounds like the first hand choice: If the compiler is 
indeed correct and this is dead code, remove it!


> Or somehow silence / remove this warning ?
>
> I wonder where this comes from, last time I built with clang  on Linux 
> I did not see those …
>

Unused code warnings in the JDK code base typically appears only for 
debug or release builds, or some other #ifdef guards.

Neither Oracle CI nor GHA builds with clang on Linux on a regular basis. 
I don't know if anyone else is doing it either. So that combination 
typically bitrots over time.

/Magnus


> Best regards, Matthias
>
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