RFR: JDK-8165946: buildjdk logic is incomplete when separate sysroots needed

[gary.adams at oracle.com]

I'll add the extra check before pushing.

         if test "x$BUILD_SYSROOT" = x; then

796         BUILD_SYSROOT="$BUILD_DEVKIT_SYSROOT"

fi

Before there was a devkit option it was common to set sysroot and toolchain
path separately. I don't know if the overlap precedence was ever specified.

On 9/14/16 4:39 AM, Erik Joelsson wrote:
> Hello,
>
> Looks ok for now.
>
> I think that for completeness, the --with-build-sysroot option should 
> also override a sysroot set by the build-devkit, but it's not that 
> important.
>
> /Erik
>
> On 2016-09-13 14:19, Gary Adams wrote:
>> When the buildjdk logic was added to the jdk9 build system, it did 
>> not completely
>> cover the use cases required in the mobile/dev builds. We have been 
>> working around
>> this issue using a prebuilt macosx buildjdk with the --with-build-jdk 
>> autoconf option.
>> This is an awkward workaround, because the buildjdk had to be new 
>> enough to match the
>> requirements of the repos being built. e.g. jdk9 b132 included some 
>> newer command line
>> option in the jmod and jlink command build step.
>>
>> This fix is a more permanent solution adding a --with-build-sysroot 
>> option to allow
>> an explicit reference to the sysroot to use on the build system. A 
>> similar call already exists
>> when --with-devkit and --with-build-devkit are used.
>>
>>    JIRA: https://bugs.openjdk.java.net/browse/JDK-8165946
>>    Webrev: http://cr.openjdk.java.net/~gadams/8165946/wevrev.00/
>>
>> This is an interim fix in the mobile/dev repos. Many of the platform 
>> specific checks will need to
>> be addressed before they can be targeted for the mainstream repos.
>>
>> Here's an example of how this would be used for an ios-arm64 build :
>>
>>
>> export 
>> IOS_SDK_PATH=/Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS.sdk
>> export 
>> MACOSX_SDK_PATH=/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.11.sdk
>> ...
>> configure \
>> ...
>>     --with-sys-root=${IOS_SDK_PATH} \
>>     --with-build-sysroot=${MACOSX_SDK_PATH}
>>
>>
>