From: Eli Schwartz <eschwartz@gentoo.org>
Date: Tue, 15 Jul 2025 14:22:07 GMT
Subject: Re: [PATCH v3] meson: disable PCRE2 dependency by default in macOS
Message-ID: <a0faa9b9-3c65-44c9-97e0-bcf2af053f5e@gentoo.org>
In-Reply-To: <CAPUEspjCbi0U6HYxEvpqMW9FPLn98VMePDTNfadQbt_9GHsZsw@mail.gmail.com>

On 7/15/25 8:01 AM, Carlo Arenas wrote:
> On Mon, Jul 14, 2025 at 6:55 PM Eli Schwartz <eschwartz@gentoo.org> wrote:
>>
>> Please double-check my work, that this compiler.has_header() is
>> sufficient on your reproducer system to detect and disable the
>> non-working feature.
> 
> it is indeed all that was needed, abd makes me wonder
> if a future version of dependency() shouldn't have a "has_header"
> parameter like the one used in find_libray() to allow for this
> validation to happen internally and fallback as needed.


It's... possible, I suppose, but usually not needed unless a distributor
doesn't respond to reports that their OS is broken. Which well, fair
enough, happens. :)

Another possibility is to add a quirk to meson's underlying python code.
If pcre2 is searched, and the platform is darwin, also check the header.
You'll need a small override in mesonbuild/dependencies/*.py, like:


class PCRE2PkgConfigDependency(PkgConfigDependency):
    def __init__(...):
        super().__init__(...)
        if is_darwin:
            self.is_found = check_that_header()


> Posted a v4 with your code and modifications to still allow a
> fallback to the wrap.


Thanks. :)

-- 
Eli Schwartz