On 07/08/2011 04:23 PM, Eric Blake wrote:
On 07/05/2011 10:18 PM, Laine Stump wrote:
I realized that PATCH 10/10 would cause the build to fail if someone did a build --with-qemu but --without-network. I'm squashing the following into the original patch to remedy that.
I'm not really a fan of putting #if all over the place, but this is similar to what's done with WITH_MACVTAP, so at least there's precedence. (This is necessary because this new "backend API" to the network driver isn't called via a pointer table filled in at runtime, as is done with the public API). Would it be any easier to instead guarantee that even when #if WITH_NETWORK is false, those same symbols are available as no-ops to allow compilation to proceed?
That would mean either defining the functions inside qemu, or creating a dummy network module replacement to be built when WITH_NETWORK is false. I like both of those options even less.
+#if WITH_NETWORK /* If appropriate, grab a physical device from the configured * network's pool of devices, or resolve bridge device name * to the one defined in the network definition. */ if (networkAllocateActualDevice(net)< 0) goto error; - +#endif That is, make networkAllocateActualDevice() be a no-op that returns 0 if there is no network support compiled in, and therefore nothing to allocate.
But where would that NOP function live? The natural place for a function called "networkSomething" is in a network driver, but there isn't one.
+++ b/tests/Makefile.am @@ -319,8 +319,11 @@ endif
if WITH_QEMU
-qemu_LDADDS = ../src/libvirt_driver_qemu.la \ - ../src/libvirt_driver_network.la +qemu_LDADDS = ../src/libvirt_driver_qemu.la + +if WITH_NETWORK +qemu_LDADDS += ../src/libvirt_driver_network.la +endif Then again, if you are compiling --without-network, you don't want to link against a library that won't be built. That would imply that any no-op stubs would have to be provided by static inline functions in the header in the no-network case.
Ah, you're doing this mail "On the Road" style (stream of consciousness with no going back to edit), so I'll respond that way too :-) Actually, I like this idea - in bridge_driver.h, I can put the function declrations inside #if WITH_NETWORK, and have a #else clause that contains inlines that return success but do nothing (exactly what is needed). That way the code in qemu won't need #if. I'll do it that way in the next version.