Re: How to get autoconf to respect CC="gcc -std=c89"?

[Zack Weinberg]

On Wed, Oct 11, 2023, at 9:34 AM, Evgeny Grin wrote:
> On 11.10.2023 16:29, Bob Friesenhahn wrote:
>> The problem is that Autoconf is defeating the recipient's freedom to
>> select the compilation settings used.
>>
>> The person who is compiling the software should be able to specify
>> the parameters to use used.
>
> It works, actually. ./configure CC=gcc CFLAGS=-std=c89
>
> C99 check would fail, compiler would be accepted as C89-compatible.

This only works if both configure.ac and all the Makefiles have been
written "correctly".  I put "correctly" in quotes because, yes, it *is*
how you should write them, and it *is* what you get if you aren't trying
to do anything complicated -- but if you *do* need to do something
complicated, it is very easy to break this property by accident and
without noticing.  And I don't think everything you need to do to avoid
breaking it is documented, so we can't even claim that we warned people.

zw