Re: [RFC PATCH] migration: Add missing dependency on GNUTLS

["Daniel P. Berrangé" <berrange@redhat.com>]

On Tue, Jun 15, 2021 at 10:39:08AM +0100, Peter Maydell wrote:
> On Mon, 14 Jun 2021 at 06:28, Philippe Mathieu-Daudé <f4bug@amsat.org> wrote:
> >
> > Commit 7de2e856533 made migration/qemu-file-channel.c include
> > "io/channel-tls.h" but forgot to add the new GNUTLS dependency
> > on Meson, leading to build failure on OSX:
> >
> >   [2/35] Compiling C object libmigration.fa.p/migration_qemu-file-channel.c.o
> >   FAILED: libmigration.fa.p/migration_qemu-file-channel.c.o
> >   cc -Ilibmigration.fa.p -I. -I.. -Iqapi [ ... ] -o libmigration.fa.p/migration_qemu-file-channel.c.o -c ../migration/qemu-file-channel.c
> >   In file included from ../migration/qemu-file-channel.c:29:
> >   In file included from include/io/channel-tls.h:26:
> >   In file included from include/crypto/tlssession.h:24:
> >   include/crypto/tlscreds.h:28:10: fatal error: 'gnutls/gnutls.h' file not found
> >   #include <gnutls/gnutls.h>
> >            ^~~~~~~~~~~~~~~~~
> >   1 error generated.
> >
> > Reported-by: Stefan Weil <sw@weilnetz.de>
> > Resolves: https://gitlab.com/qemu-project/qemu/-/issues/407
> > Fixes: 7de2e856533 ("yank: Unregister function when using TLS migration")
> > Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
> 
> Is there really no way to get Meson to handle this kind
> of thing properly (ie "just put all the include paths in the CFLAGS
> for every compilation") rather than requiring us to add dependency
> markers all over the meson.build files every time we add some
> extra #include somewhere ? This is demonstrably horribly fragile
> the way we have it at the moment :-(

A better way to fix this might be to figure out a change to make the
crypto struct definitions be private in the .c file, since the public
callers should not need to see them. That would let us remove the
#include for gnutls from the header.

Regards,
Daniel
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