Re: [PATCH] regex: not all macOS platforms seem to have REG_ENHANCED

From: Junio C Hamano <gitster@pobox.com>
Date: Mar 20, 2026, 16:50 UTC
Message-ID: <xmqqcy0yfnsb.fsf@gitster.g>
In-Reply-To: <6636e7d2-7a1d-0108-2e62-af27a3ae3cf3@gmx.de>

Johannes Schindelin <Johannes.Schindelin@gmx.de> writes:

> While this lets the build pass, it _does_ change behavior. Where
> previously, EREs were enforced, now BREs are silently enforced.

Enhanced is not about ERE/BRE but yes, you're right. A build that does not support REG_ENHANCED (due to the lack of definition in the header) would compile but without enhanced features like \b, so the "patch" above would not something I want to apply and blamed by macOS users for X-<.

Show 12 quoted lines

> So it might be desirable to instead imitate what `meson.build` does,
> namely define `USE_ENHANCED_BASIC_REGULAR_EXPRESSIONS` on macOS when
> compiling with `clang`.
>
> But that should already be the case:
> https://gitlab.com/git-scm/git/-/blob/v2.53.0/config.mak.uname#L151
>
>> ifeq ($(uname_S),Darwin)
>> [...]
>> 	USE_ENHANCED_BASIC_REGULAR_EXPRESSIONS = YesPlease
>
> So: hmm.

Hmm, indeed.