RFR: JDK-8323008: filter out any -std* flags added by autoconf from CC/CXX [v2]

[Matthias Baesken]

On Thu, 11 Jan 2024 11:19:01 GMT, Magnus Ihse Bursie <ihse at openjdk.org> wrote:

>> Matthias Baesken has updated the pull request incrementally with one additional commit since the last revision:
>> 
>>   Adjust GREP call
>
> make/autoconf/toolchain.m4 line 395:
> 
>> 393:   # filter out some unwanted additions autoconf may add to CXX; we saw this on macOS with autoconf 2.72
>> 394:   UTIL_GET_NON_MATCHING_VALUES(cxx_filtered, $CXX, -std=c++11 -std=gnu++11)
>> 395:   if test "x$cxx_filtered" != x; then
> 
> Why this test? If CXX is empty, then xcc_filtered will be empty too, right? And if CXX is exactly `-std=c++11`, then this test will render cxx_filter empty too, which will not change CXX -- which I believe is not what you want?

Probably you are right; I think I 'borrowed'  the pattern with the additional` if test` from some other places where UTIL_GET_NON_MATCHING_VALUES is used (e.g. jvm-features.m4).
Should I remove the  test ?

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PR Review Comment: https://git.openjdk.org/jdk/pull/17301#discussion_r1448847359