[PULL,02/16] meson: move block.syms dependency out of libblock

Commit Message

Paolo Bonzini July 4, 2024, 9:57 a.m. UTC

In order to define libqemuutil symbols that are requested by block modules,
QEMU currently uses a combination of the "link_depends" argument of
libraries (which is propagated into dependencies, but not available in
dependencies) and the "link_args" argument of declare_dependency()
(which _is_ available in static_library, but probably not used for
historical reasons only).

Unfortunately the link_depends will not be propagated into the
"block" dependency if it is defined using
declare_dependency(objects: ...); and it is not possible to
add it directly to the dependency because the keyword argument
simply is not available.

The only solution, in order to switch to defining the dependency
without using "link_whole" (which has problems of its own, see
https://github.com/mesonbuild/meson/pull/8151#issuecomment-754796420),
is unfortunately to add the link_args and link_depends to the
executables directly; fortunately there is just four of them.

It is possible (and I will look into it) to add "link_depends"
to declare_dependency(), but it probably will be a while before
QEMU can use it.

Signed-off-by: Paolo Bonzini <[e-mail]>
---
 meson.build                | 5 +++--
 storage-daemon/meson.build | 1 +
 2 files changed, 4 insertions(+), 2 deletions(-)

Patch

diff --git a/meson.build b/meson.build
index 8909f8c87d9..df9a64302f0 100644
--- a/meson.build
+++ b/meson.build
@@ -3759,12 +3759,10 @@  system_ss.add(migration)
 block_ss = block_ss.apply({})
 libblock = static_library('block', block_ss.sources() + genh,
                           dependencies: block_ss.dependencies(),
-                          link_depends: block_syms,
                           name_suffix: 'fa',
                           build_by_default: false)
 
 block = declare_dependency(link_whole: [libblock],
-                           link_args: '@block.syms',
                            dependencies: [crypto, io])
 
 blockdev_ss = blockdev_ss.apply({})
@@ -4033,10 +4031,13 @@  endif
 
 if have_tools
   qemu_img = executable('qemu-img', [files('qemu-img.c'), hxdep],
+             link_args: '@block.syms', link_depends: block_syms,
              dependencies: [authz, block, crypto, io, qom, qemuutil], install: true)
   qemu_io = executable('qemu-io', files('qemu-io.c'),
+             link_args: '@block.syms', link_depends: block_syms,
              dependencies: [block, qemuutil], install: true)
   qemu_nbd = executable('qemu-nbd', files('qemu-nbd.c'),
+               link_args: '@block.syms', link_depends: block_syms,
                dependencies: [blockdev, qemuutil, gnutls, selinux],
                install: true)
 
diff --git a/storage-daemon/meson.build b/storage-daemon/meson.build
index 46267b63e72..fd5e32f4b28 100644
--- a/storage-daemon/meson.build
+++ b/storage-daemon/meson.build
@@ -8,6 +8,7 @@  if have_tools
   qsd_ss = qsd_ss.apply({})
   qsd = executable('qemu-storage-daemon',
                    qsd_ss.sources(),
+                   link_args: '@block.syms', link_depends: block_syms,
                    dependencies: qsd_ss.dependencies(),
                    install: true)
 endif