[pacman-dev] [PATCH 2/5] meson.build: Fix detection of symbols

[Emil Velikov]

On Mon, 19 Apr 2021 at 08:10, Allan McRae <allan at archlinux.org> wrote:
>
> On 17/4/21 1:45 pm, Mark Weiman wrote:
> > This patch changes the behavior of meson to define configuration options
> > *only* when the symbol checked is present. Currently, it defines all of
> > them in config.h whether the symbol exists or not and the code that
> > looks for it doesn't check the macro's value, but whether it's defined.
> >
>
> Remember back when we used autotools and all this just worked!  :D
>
> Patch looks good to me.
>
Food for thought:

Usually the more robust approach is to always set the respective
defines to 0/1 and evaluate them directly (aka #if HAVE_).
In addition one could set -Werror=undef in the build to catch any issues.

This will produce clear traces with potential issues, while #if
defined will silently fallback to the "other" path.
If people are OK with the above, I will follow-up with some patches.

Note: above suggestion is not meant to dismiss the original patch.

-Emil