RFR: 8366777: Build fails unknown pseudo-op with old AS on linux-aarch64 [v18]

[Erik Joelsson]

On Fri, 12 Sep 2025 16:28:00 GMT, Erik Joelsson <erikj at openjdk.org> wrote:

>> Oh, and also, you can extract a common:
>> 
>> AC_MSG_RESULT([$AARCH64_SVE_AVAILABLE])
>> 
>> after the compile test. This lets you get rid of the else block completely, and it makes it clear that the AC_MSG_CHECKING is always terminated. (Apart from being shorter)
>
>> You are not supposed to both provide AVAILABLE and CHECK_AVAILABLE. Also, if you do setup CHECK_AVAILABLE you should always provide a value to the AVAILABLE variable; now you don't have an else clause for the cpu and toolchain tests. Also, CHECK_AVAILABLE was designed for small and simple tests; this is so long it becames hard to read.
>> 
>> Instead I suggest the following: Start by setting AARCH64_SVE_AVAILABLE to false. Then do the code that is currently in the CHECK_AVAILABLE block, but replace the assignment to AVAILABLE with an assignment to AARCH64_SVE_AVAILABLE. (Where it is true, since you defaulted it to false you can skip that line).
>> 
>> Then, finally, you can do like this:
>> 
>> ```
>>  UTIL_ARG_ENABLE(NAME: aarch64-sve, DEFAULT: auto,
>>     RESULT: AARCH64_SVE_ENABLED,
>>     DESC: [Use SVE when compiling libsleef],
>>     AVAILABLE: $AARCH64_SVE_AVAILABLE)
>> ```
> 
> Here is the code evaluating AVAILABLE:
> 
> 
>   # Check if the option is available
>   AVAILABLE=ARG_AVAILABLE
>   # Run the available check block (if any), which can overwrite AVAILABLE.
>   ARG_CHECK_AVAILABLE
> 
> Which is why I interpreted it as ok to supply both AVAILABLE as a default and AVAILABLE_CHECK.
> 
> Also I don't agree that this is too big to be inline. I think it's perfectly readable.

The issue with using the AVAILABLE variable in `AC_MSG_RESULT` is that it has the values true/false not yes/no, which is the common output for results of configure tests.

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PR Review Comment: https://git.openjdk.org/jdk/pull/27073#discussion_r2344827094