Re: QEMU build error with --disable-qcow1

[Paolo Bonzini <pbonzini@redhat.com>]

On 28/08/20 18:34, Thomas Huth wrote:
> 
> Linking target qemu-nbd
> libblock.fa(block_qcow2-threads.c.o): In function `qcow2_zlib_compress':
> /tmp/qemu-test/../../home/thuth/devel/qemu/block/qcow2-threads.c:101:
> undefined reference to `deflateInit2_'
> /tmp/qemu-test/../../home/thuth/devel/qemu/block/qcow2-threads.c:116:
> undefined reference to `deflate'
> /tmp/qemu-test/../../home/thuth/devel/qemu/block/qcow2-threads.c:123:
> undefined reference to `deflateEnd'
> libblock.fa(block_qcow2-threads.c.o): In function `qcow2_zlib_decompress':
> /tmp/qemu-test/../../home/thuth/devel/qemu/block/qcow2-threads.c:152:
> undefined reference to `inflateInit2_'
> /tmp/qemu-test/../../home/thuth/devel/qemu/block/qcow2-threads.c:157:
> undefined reference to `inflate'
> /tmp/qemu-test/../../home/thuth/devel/qemu/block/qcow2-threads.c:169:
> undefined reference to `inflateEnd'
> etc.
> 
> Not sure whether this is due to the recent conversion to meson, or a
> recent change to that file ... anybody got a clue what's going on here?

It's a missing zlib dependency for the qcow2 files:

diff --git a/block/meson.build b/block/meson.build
index 4dbbfe60b4..a3e56b7cd1 100644
--- a/block/meson.build
+++ b/block/meson.build
@@ -40,9 +40,9 @@ block_ss.add(files(
   'vmdk.c',
   'vpc.c',
   'write-threshold.c',
-), zstd)
+), zstd, zlib)

-block_ss.add(when: [zlib, 'CONFIG_QCOW1'], if_true: files('qcow.c'))
+block_ss.add(when: 'CONFIG_QCOW1', if_true: files('qcow.c'))
 block_ss.add(when: 'CONFIG_VDI', if_true: files('vdi.c'))
 block_ss.add(when: 'CONFIG_CLOOP', if_true: files('cloop.c'))
 block_ss.add(when: 'CONFIG_BOCHS', if_true: files('bochs.c'))

(and then it becomes redundant for qcow1).  I'll send a formal patch
shortly.

Paolo