Re: How to link new libraries when building emacs

[Elijah G]

On Tue, Apr 2, 2024 at 11:52 PM Po Lu <luangruo@yahoo.com> wrote:
>
> Elijah G <eg642616@gmail.com> writes:
>
> > Hello, i don't know if this is a good place to ask this, i'm building
> > emacs with an additional library (exactly d2d1.h), however i'm getting
> > errors that library isn't linking, I have been looking for how to
> > solve it, but nothing, even i've tried searching in commits about
> > other libraries imported but I ended up getting lost. So If anyone
> > knows I would greatly appreciate it.
>
> Unless this library exists in Windows 9X, merely linking with the
> library will not suffice; it must be dynamically loaded, and its
> functions avoided on systems that predate their introduction.  Grepping
> for "LoadLibrary" should return plenty of examples.
>

Thank you, I thought I had to modify autoconf files to import the library
like libjansson or windows.h, I'll test it.

> Also, reading
>
>   https://github.com/apitrace/dxsdk/blob/master/Include/d2d1.h
>
> d2d1 is also a C++ library, while Emacs headers expect a C compiler and
> probably cannot be made to compile otherwise without substantial effort
> and creating a new burden on the rest of us, so it's not possible to
> make use of its functionality unless we decide to require a C++ compiler
> for the MS Windows port, and even then not without restricting calls to
> C++ functions in files isolated from Emacs facilities which in turn
> export C interfaces to such functionality.  I'm not confident that
> MinGW's C++ ABI is stable enough to support loading C++ libraries at
> runtime either.
>

I don't know if there are already libraries in emacs that also are C++,
I'm trying to get support for color emojis in the NT port and the only library
that I know allows this is d2d1.h, I needed to test if it's possible with
msys2 mingw tools.

> > Also I would like to know where the font display source is stored,
>
> It's divided among w32font.c, w32uniscribe.c and hbfont.c, AFAIK.
>

Thanks.

> Finally, emacs-devel@gnu.org is a far more suitable venue for questions
> regarding Emacs development.

Thanks, I think I'll resend this to emacs-devel@gnu.org to know more
about this.