1:04 p.m.
Version 1 was here:
https://www.redhat.com/archives/libguestfs/2020-April/thread.html#00160
Version 2 side-steps the objections to the first patch by using a
well-formed alternate nbdkit.pc file and running ordinary pkg-config
against it, so any parsing of --cflags etc will be done by pkg-config.
The first patch is essentially the same idea as:
https://github.com/libguestfs/libnbd/commit/dc87a1a6d6918ac5477e1d6b22599...
(which follows on from similar tricks in libguestfs and libvirt).
Rich.
1:04 p.m.
New subject: [PATCH nbdkit 1/2] server: Add pkg-config file to compile against locally compiled nbdkit.
In most cases it is incorrect to use this - pay attention to the note
at the top of the newly added file.
---
.gitignore | 1 +
configure.ac | 1 +
server/local/nbdkit.pc.in | 45 +++++++++++++++++++++++++++++++++++++++
3 files changed, 47 insertions(+)
diff --git a/.gitignore b/.gitignore
index 4f6fcf1b..8c701295 100644
--- a/.gitignore
+++ b/.gitignore
@@ -83,6 +83,7 @@ plugins/*/*.3
/plugins/tar/nbdkit-tar-plugin
/plugins/tmpdisk/default-command.c
/podwrapper.pl
+/server/local/nbdkit.pc
/server/nbdkit
/server/nbdkit.pc
/server/synopsis.c
diff --git a/configure.ac b/configure.ac
index b71d9d8c..17d8d676 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1088,6 +1088,7 @@ AC_CONFIG_FILES([Makefile
filters/truncate/Makefile
filters/xz/Makefile
fuzzing/Makefile
+ server/local/nbdkit.pc
server/Makefile
server/nbdkit.pc
tests/functions.sh
diff --git a/server/local/nbdkit.pc.in b/server/local/nbdkit.pc.in
new file mode 100644
index 00000000..96c33d2f
--- /dev/null
+++ b/server/local/nbdkit.pc.in
@@ -0,0 +1,45 @@
+# nbdkit
+# Copyright (C) 2013-2020 Red Hat Inc.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met:
+#
+# * Redistributions of source code must retain the above copyright
+# notice, this list of conditions and the following disclaimer.
+#
+# * Redistributions in binary form must reproduce the above copyright
+# notice, this list of conditions and the following disclaimer in the
+# documentation and/or other materials provided with the distribution.
+#
+# * Neither the name of Red Hat nor the names of its contributors may be
+# used to endorse or promote products derived from this software without
+# specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY RED HAT AND CONTRIBUTORS ''AS IS'' AND
+# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
+# THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
+# PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL RED HAT OR
+# CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
+# USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+# ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+# OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+# OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+# SUCH DAMAGE.
+
+# This alternate pkg-config file may be used to compile plugins
+# against a locally compiled (but not installed) nbdkit. Note you
+# probably should *not* use this in most cases, since your plugin will
+# may end up containing hard paths to the local nbdkit sources.
+
+prefix=@abs_top_builddir@
+exec_prefix=@abs_top_builddir@
+
+Name: @PACKAGE_NAME@
+Version: @PACKAGE_VERSION@
+Description: A toolkit for creating NBD servers
+Requires:
+Cflags: -I@abs_top_srcdir@/include -I@abs_top_builddir@/include
+Libs:
--
2.18.2
1:08 p.m.
New subject: [PATCH nbdkit 1/2] server: Add pkg-config file to compile against locally compiled nbdkit.
On Thu, Apr 23, 2020 at 07:04:14PM +0100, Richard W.M. Jones wrote:
+# probably should *not* use this in most cases, since your plugin
will
+# may end up containing hard paths to the local nbdkit sources.
"will may" -> "may" in my local copy.
Rich.
--
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
Read my programming and virtualization blog: http://rwmj.wordpress.com
virt-p2v converts physical machines to virtual machines. Boot with a
live CD or over the network (PXE) and turn machines into KVM guests.
http://libguestfs.org/virt-v2v
1:11 p.m.
New subject: [PATCH nbdkit 1/2] server: Add pkg-config file to compile against locally compiled nbdkit.
On Thu, Apr 23, 2020 at 07:08:43PM +0100, Richard W.M. Jones wrote:
On Thu, Apr 23, 2020 at 07:04:14PM +0100, Richard W.M. Jones wrote:
> +# probably should *not* use this in most cases, since your plugin will
> +# may end up containing hard paths to the local nbdkit sources.
"will may" -> "may" in my local copy.
Actually in hindsight perhaps this comment/warning is wrong. I was
thinking about the original nbdkit.pc which contains absolute paths to
things like plugindir and filterdir. However firstly this one doesn't
contain these paths, and in any case even if it did they would be
unlikely to end up inside a C plugin.
Rich.
--
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
Read my programming and virtualization blog: http://rwmj.wordpress.com
virt-p2v converts physical machines to virtual machines. Boot with a
live CD or over the network (PXE) and turn machines into KVM guests.
http://libguestfs.org/virt-v2v
2:39 p.m.
New subject: [PATCH nbdkit 1/2] server: Add pkg-config file to compile against locally compiled nbdkit.
On 4/23/20 1:11 PM, Richard W.M. Jones wrote:
On Thu, Apr 23, 2020 at 07:08:43PM +0100, Richard W.M. Jones wrote:
> On Thu, Apr 23, 2020 at 07:04:14PM +0100, Richard W.M. Jones wrote:
>> +# probably should *not* use this in most cases, since your plugin will
>> +# may end up containing hard paths to the local nbdkit sources.
>
> "will may" -> "may" in my local copy.
Actually in hindsight perhaps this comment/warning is wrong. I was
thinking about the original nbdkit.pc which contains absolute paths to
things like plugindir and filterdir. However firstly this one doesn't
contain these paths, and in any case even if it did they would be
unlikely to end up inside a C plugin.
Yeah, the comment is too strong. If --cflags produced
-Dsomedir=/path/to/in-tree, then you indeed would want this sort of
disclaimer, but without that, all you are affecting is the ability to
link against an uninstalled build. There's a chance that your plugin
will only be runnable by the in-tree nbdkit (if it used anything that
the installed nbdkit does not provide or understand), but that's
different than stating that your plugin will have a hard path to the
uninstalled nbdkit sources.
At any rate, once you tweak that sentence, the patch looks good, and
coupled with 2/2, fixed the build for me.
--
Eric Blake, Principal Software Engineer
Red Hat, Inc. +1-919-301-3226
Virtualization: qemu.org | libvirt.org
1:04 p.m.
New subject: [PATCH nbdkit 2/2] golang: Compile against the local nbdkit build, not installed.
When compiling when an older nbdkit is installed, the build would fail
because certain symbols such as .get_ready were not defined:
../../src/libguestfs.org/nbdkit/nbdkit.go:541:8: plugin.get_ready undefined (type
_Ctype_struct_nbdkit_plugin has no field or method get_ready)
This happens because we were using the installed <nbdkit-plugin.h>
rather than the local copy.
We don't want to modify the *.go files themselves as they might be
copied into other projects. Instead we can set PKG_CONFIG_PATH to
point to the local nbdkit.pc which will return the correct CFLAGS.
Fixes: commit 1ff44288ae1cf95428283e252edd9474c3fe3b55
Thanks: Dan Berrangé, Eric Blake
---
plugins/golang/Makefile.am | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/plugins/golang/Makefile.am b/plugins/golang/Makefile.am
index f189184c..d8d19b7a 100644
--- a/plugins/golang/Makefile.am
+++ b/plugins/golang/Makefile.am
@@ -66,18 +66,21 @@ noinst_DATA = \
examples/dump-plugin/nbdkit-godump-plugin.so: \
$(plugin_sources) examples/dump-plugin/dumpplugin.go
cd examples/dump-plugin && \
+ PKG_CONFIG_PATH="$(abs_builddir)/server/local" \
GOPATH="$(abs_builddir)" \
$(GOLANG) build -o nbdkit-godump-plugin.so -buildmode=c-shared
examples/minimal/nbdkit-gominimal-plugin.so: \
$(plugin_sources) examples/minimal/minimal.go
cd examples/minimal && \
+ PKG_CONFIG_PATH="$(abs_builddir)/server/local" \
GOPATH="$(abs_builddir)" \
$(GOLANG) build -o nbdkit-gominimal-plugin.so -buildmode=c-shared
examples/ramdisk/nbdkit-goramdisk-plugin.so: \
$(plugin_sources) examples/ramdisk/ramdisk.go
cd examples/ramdisk && \
+ PKG_CONFIG_PATH="$(abs_builddir)/server/local" \
GOPATH="$(abs_builddir)" \
$(GOLANG) build -o nbdkit-goramdisk-plugin.so -buildmode=c-shared
@@ -87,6 +90,7 @@ check_DATA = test/nbdkit-gotest-plugin.so
test/nbdkit-gotest-plugin.so: $(plugin_sources) test/test.go
cd test && \
+ PKG_CONFIG_PATH="$(abs_builddir)/server/local" \
GOPATH="$(abs_builddir)" \
$(GOLANG) build -o nbdkit-gotest-plugin.so -buildmode=c-shared
--
2.18.2
1:22 p.m.
New subject: [PATCH nbdkit 2/2] golang: Compile against the local nbdkit build, not installed.
On 4/23/20 1:04 PM, Richard W.M. Jones wrote:
When compiling when an older nbdkit is installed, the build would
fail
because certain symbols such as .get_ready were not defined:
../../src/libguestfs.org/nbdkit/nbdkit.go:541:8: plugin.get_ready undefined (type
_Ctype_struct_nbdkit_plugin has no field or method get_ready)
This happens because we were using the installed <nbdkit-plugin.h>
rather than the local copy.
We don't want to modify the *.go files themselves as they might be
copied into other projects. Instead we can set PKG_CONFIG_PATH to
point to the local nbdkit.pc which will return the correct CFLAGS.
Fixes: commit 1ff44288ae1cf95428283e252edd9474c3fe3b55
Thanks: Dan Berrangé, Eric Blake
---
plugins/golang/Makefile.am | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/plugins/golang/Makefile.am b/plugins/golang/Makefile.am
index f189184c..d8d19b7a 100644
--- a/plugins/golang/Makefile.am
+++ b/plugins/golang/Makefile.am
@@ -66,18 +66,21 @@ noinst_DATA = \
examples/dump-plugin/nbdkit-godump-plugin.so: \
$(plugin_sources) examples/dump-plugin/dumpplugin.go
cd examples/dump-plugin && \
+ PKG_CONFIG_PATH="$(abs_builddir)/server/local" \
Shouldn't this be more like:
PKG_CONFIG_PATH="$(abs_builddir)/server/local$${PKG_CONFIG_PATH:-:$$PKG_CONFIG_PATH}"
so as to preserve any inherited override locations for other .pc files
that might also be needed by cgo?
--
Eric Blake, Principal Software Engineer
Red Hat, Inc. +1-919-301-3226
Virtualization: qemu.org | libvirt.org
1:06 p.m.
On Thu, Apr 23, 2020 at 07:04:13PM +0100, Richard W.M. Jones wrote:
Version 1 was here:
https://www.redhat.com/archives/libguestfs/2020-April/thread.html#00160
Version 2 side-steps the objections to the first patch by using a
well-formed alternate nbdkit.pc file and running ordinary pkg-config
against it, so any parsing of --cflags etc will be done by pkg-config.
The first patch is essentially the same idea as:
https://github.com/libguestfs/libnbd/commit/dc87a1a6d6918ac5477e1d6b22599...
(which follows on from similar tricks in libguestfs and libvirt).
For both patches
Reviewed-by: Daniel P. Berrangé <berrange(a)redhat.com>
Regards,
Daniel
--
|: https://berrange.com -o- https://www.flickr.com/photos/dberrange :|
|: https://libvirt.org -o- https://fstop138.berrange.com :|
|: https://entangle-photo.org -o- https://www.instagram.com/dberrange :|
1598
days inactive
1598
days old
7 comments
3 participants
participants (3)
-
Daniel P. Berrangé -
Eric Blake -
Richard W.M. Jones