Re: [PATCH-for-8.0] block/dmg: Ignore C99 prototype declaration mismatch from <lzfse.h>

[Stefan Weil]

Am 27.03.23 um 23:09 schrieb Paolo Bonzini:

Il lun 27 mar 2023, 20:58 Philippe Mathieu-Daudé <philmd@linaro.org> ha scritto:

> The warning can also be suppressed if the build uses `-isystem
> /opt/homebrew/include` instead of `-I/opt/homebrew/include` as I just
> have tested.

Is that option added by QEMU's configure or meson.build? Or is it added by homebrew? The fact that /opt/homebrew/include it isn't considered a system seems to be a homebrew decision.

IIUC by design meson only allows including *relative* directories,
and manage the system ones:
https://mesonbuild.com/Include-directories.html

That's for includes that are part of QEMU.

Meson has as_system for dependency objects (https://mesonbuild.com/Reference-manual_returned_dep.html) but lzfse doesn't have a .pc file, its detection has to be done by hand.

Paolo

> If we can find a solution how to implement that I thing it would look
> nicer. Technically the patch looks good.
>
> Reviewed-by: Stefan Weil <sw@weilnetz.de>

Thanks!

Typically I configure the build on macOS with `./configure --extra-cflags=-I/opt/homebrew/include --extra-ldflags=-L/opt/homebrew/lib --disable-werror`. With that configuration I get the two warnings for lzfse.h.

When I use `./configure '--extra-cflags=-isystem /opt/homebrew/include' --extra-ldflags=-L/opt/homebrew/lib --disable-werror` instead, I get no compiler warnings (and `--disable-werror` could be ommitted).

So at least for macOS with Homebrew in /opt/homebrew (M1 / M2 Macs) the patch is not needed when the right configure options (`--extra-cflags`) were used.

Stefan