RFR: 8348207: Linux PPC64 PCH build broken after JDK-8347909 [v2]

[Martin Doerr]

On Fri, 24 Jan 2025 14:58:24 GMT, Matthias Baesken <mbaesken at openjdk.org> wrote:

>> The Linux PPC64 PCH build was broken after JDK-8347909.
>> Build error
>> 
>> * For target hotspot_variant-server_libjvm_objs_sharedRuntimeTrans.o:
>> cc1plus: error: /jdk25_opt/hotspot/variant-server/libjvm/objs/precompiled/precompiled.hpp.gch: created and used with differing settings of '-mpower8-fusion-sign' [-Werror=invalid-pch]
>> cc1plus: error: one or more PCH files were found, but they were invalid
>> <command-line>: fatal error: precompiled.hpp: No such file or directory
>> 
>> * For target hotspot_variant-server_libjvm_objs_sharedRuntimeTrig.o:
>> cc1plus: error: /jdk25_opt/hotspot/variant-server/libjvm/objs/precompiled/precompiled.hpp.gch: created and used with differing settings of '-mpower8-fusion-sign' [-Werror=invalid-pch]
>> cc1plus: error: one or more PCH files were found, but they were invalid
>> <command-line>: fatal error: precompiled.hpp: No such file or directory
>> 
>> 
>> There was a mismatch of the build settings of  precompiled.hpp.gch and these 2 compilation units leading to this error;  the PCH build exclusion of these 2 files did not work.
>
> Matthias Baesken has updated the pull request incrementally with one additional commit since the last revision:
> 
>   adjust gcc PCH exclusion on ppc64le

A couple of things could be revisited like the `OPT_SPEED_SRC`. But, this PR to fix the build still looks good to me.

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

Marked as reviewed by mdoerr (Reviewer).

PR Review: https://git.openjdk.org/jdk/pull/23268#pullrequestreview-2572953500