RFR: 8247396: PCH should be disabled for opt-size feature with clang after JDK-8246751

[jiefu(傅杰)]

Hi Erik,

Thanks for your review and valuable comments.

Updated: http://cr.openjdk.java.net/~jiefu/8247396/webrev.01/

Please review it and give me some adviece.

Thanks a lot.
Best regards,
Jie

On 2020/6/11, 8:37 PM, "Erik Joelsson" <erik.joelsson at oracle.com> wrote:

    I agree with the assessment, but I think the disabling should happen in 
    configure. That way the configure log can accurately tell the user why 
    it was disabled. This can be done by just adding another elif in 
    BPERF_SETUP_PRECOMPILED_HEADERS. To check for a jvm feature in 
    configure, you can use JVM_FEATURES_IS_ACTIVE(opt-size).
    
    /Erik
    
    On 2020-06-11 02:25, jiefu(傅杰) wrote:
    > Hi all,
    >
    > JBS:    https://bugs.openjdk.java.net/browse/JDK-8247396
    > Webrev: http://cr.openjdk.java.net/~jiefu/8247396/webrev.00/
    >
    > -O3 is used for clang on MacOS after JDK-8246751.
    > But it breaks the builds of VMs with opt-size feature when PCH is enabled.
    >
    > The reason is that the PCH was built with -Os while some other files were built with -O3, which causes an error with clang.
    > It would be better to disable the PCH for opt-size builds.
    >
    > Thanks a lot.
    > Best regards,
    > Jie