[libvirt] [python PATCH] build: make it easier to backport event ids
Eric Blake
eblake at redhat.com
Thu Jan 15 03:08:16 UTC 2015
In some cases, it is very easy for downstream distros to backport
enum values without requiring a .so bump. Keying the conditional
code off of the upstream version where the enum value was added
is not ideal, because downstream then has to patch that the feature
is available in their build that still reports an earlier version
number. For example, if RHEL 7 backports events from 1.2.11 into
a build based on 1.2.8, building the python bindings would warn:
libvirt-override.c: In function ‘libvirt_virConnectDomainEventRegisterAny’:
libvirt-override.c:6653:5: warning: enumeration value ‘VIR_DOMAIN_EVENT_ID_TUNABLE’ not handled in switch [-Wswitch]
switch ((virDomainEventID) eventID) {
^
libvirt-override.c:6653:5: warning: enumeration value ‘VIR_DOMAIN_EVENT_ID_AGENT_LIFECYCLE’ not handled in switch [-Wswitch]
The solution is simple - use feature-based probes instead of
version probes. Since we already scrape the XML API document of
whatever libvirt build we are binding, and that XML already
documents any downstream enum additions, we can use those as the
features for gating conditional compilation.
* generator.py (enum): Track event id names.
(buildStubs): Output define wrappers for events.
* libvirt-override.c
(libvirt_virConnectDomainEventBalloonChangeCallback)
(libvirt_virConnectDomainEventPMSuspendDiskCallback)
(libvirt_virConnectDomainEventDeviceRemovedCallback)
(libvirt_virConnectDomainEventTunableCallback)
(libvirt_virConnectDomainEventAgentLifecycleCallback)
(libvirt_virConnectDomainEventRegisterAny): Use them.
Signed-off-by: Eric Blake <eblake at redhat.com>
---
I mentioned this idea on the list a while back, and finally
got time to code it up in a much nicer way than my initial
attempt that would have polluted libvirt.h proper.
https://www.redhat.com/archives/libvir-list/2014-October/msg00186.html
I'm relatively weak at python, and welcome to suggestions on how
to avoid the long line in generator.py (maybe a regex match on
VIR_.*_EVENT_ID_, but what's the canonical way to write that in
python?)
generator.py | 11 +++++++++--
libvirt-override.c | 46 +++++++++++++++++++++++-----------------------
2 files changed, 32 insertions(+), 25 deletions(-)
diff --git a/generator.py b/generator.py
index cf044c9..4fd6d55 100755
--- a/generator.py
+++ b/generator.py
@@ -9,6 +9,7 @@ qemu_functions = {}
enums = {} # { enumType: { enumConstant: enumValue } }
lxc_enums = {} # { enumType: { enumConstant: enumValue } }
qemu_enums = {} # { enumType: { enumConstant: enumValue } }
+event_ids = []
import os
import sys
@@ -219,6 +220,8 @@ def lxc_function(name, desc, ret, args, file, module, cond):
def enum(type, name, value):
if type not in enums:
enums[type] = {}
+ if name.startswith('VIR_DOMAIN_EVENT_ID_') or name.startswith('VIR_NETWORK_EVENT_ID_'):
+ event_ids.append(name)
if value == 'VIR_TYPED_PARAM_INT':
value = 1
elif value == 'VIR_TYPED_PARAM_UINT':
@@ -910,10 +913,10 @@ def buildStubs(module, api_xml):
wrapper_file = "build/%s.c" % module
include = open(header_file, "w")
- include.write("/* Generated */\n\n")
+ include.write("/* Generated by generator.py */\n\n")
export = open(export_file, "w")
- export.write("/* Generated */\n\n")
+ export.write("/* Generated by generator.py */\n\n")
wrapper = open(wrapper_file, "w")
wrapper.write("/* Generated by generator.py */\n\n")
@@ -943,6 +946,10 @@ def buildStubs(module, api_xml):
# Write C pointer conversion functions.
for classname in primary_classes:
print_c_pointer(classname, wrapper, export, include)
+ # Write define wrappers around event id enums
+ include.write("\n")
+ for event_id in event_ids:
+ include.write("#define %s %s\n" % (event_id, event_id))
include.close()
export.close()
diff --git a/libvirt-override.c b/libvirt-override.c
index e51c44d..88cb527 100644
--- a/libvirt-override.c
+++ b/libvirt-override.c
@@ -4,7 +4,7 @@
* entry points where an automatically generated stub is
* unpractical
*
- * Copyright (C) 2005, 2007-2014 Red Hat, Inc.
+ * Copyright (C) 2005, 2007-2015 Red Hat, Inc.
*
* Daniel Veillard <veillard at redhat.com>
*/
@@ -6346,7 +6346,7 @@ libvirt_virConnectDomainEventPMSuspendCallback(virConnectPtr conn ATTRIBUTE_UNUS
}
-#if LIBVIR_CHECK_VERSION(0, 10, 0)
+#ifdef VIR_DOMAIN_EVENT_ID_BALLOON_CHANGE
static int
libvirt_virConnectDomainEventBalloonChangeCallback(virConnectPtr conn ATTRIBUTE_UNUSED,
virDomainPtr dom,
@@ -6398,9 +6398,9 @@ libvirt_virConnectDomainEventBalloonChangeCallback(virConnectPtr conn ATTRIBUTE_
LIBVIRT_RELEASE_THREAD_STATE;
return ret;
}
-#endif /* LIBVIR_CHECK_VERSION(0, 10, 0) */
+#endif /* VIR_DOMAIN_EVENT_ID_BALLOON_CHANGE */
-#if LIBVIR_CHECK_VERSION(1, 0, 0)
+#ifdef VIR_DOMAIN_EVENT_ID_PMSUSPEND_DISK
static int
libvirt_virConnectDomainEventPMSuspendDiskCallback(virConnectPtr conn ATTRIBUTE_UNUSED,
virDomainPtr dom,
@@ -6452,9 +6452,9 @@ libvirt_virConnectDomainEventPMSuspendDiskCallback(virConnectPtr conn ATTRIBUTE_
LIBVIRT_RELEASE_THREAD_STATE;
return ret;
}
-#endif /* LIBVIR_CHECK_VERSION(1, 0, 0) */
+#endif /* VIR_DOMAIN_EVENT_ID_PMSUSPEND_DISK */
-#if LIBVIR_CHECK_VERSION(1, 1, 1)
+#ifdef VIR_DOMAIN_EVENT_ID_DEVICE_REMOVED
static int
libvirt_virConnectDomainEventDeviceRemovedCallback(virConnectPtr conn ATTRIBUTE_UNUSED,
virDomainPtr dom,
@@ -6504,9 +6504,9 @@ libvirt_virConnectDomainEventDeviceRemovedCallback(virConnectPtr conn ATTRIBUTE_
LIBVIRT_RELEASE_THREAD_STATE;
return ret;
}
-#endif /* LIBVIR_CHECK_VERSION(1, 1, 1) */
+#endif /* VIR_DOMAIN_EVENT_ID_DEVICE_REMOVED */
-#if LIBVIR_CHECK_VERSION(1, 2, 9)
+#ifdef VIR_DOMAIN_EVENT_ID_TUNABLE
static int
libvirt_virConnectDomainEventTunableCallback(virConnectPtr conn ATTRIBUTE_UNUSED,
virDomainPtr dom,
@@ -6564,9 +6564,9 @@ libvirt_virConnectDomainEventTunableCallback(virConnectPtr conn ATTRIBUTE_UNUSED
return ret;
}
-#endif /* LIBVIR_CHECK_VERSION(1, 2, 9) */
+#endif /* VIR_DOMAIN_EVENT_ID_TUNABLE */
-#if LIBVIR_CHECK_VERSION(1, 2, 11)
+#ifdef VIR_DOMAIN_EVENT_ID_AGENT_LIFECYCLE
static int
libvirt_virConnectDomainEventAgentLifecycleCallback(virConnectPtr conn ATTRIBUTE_UNUSED,
virDomainPtr dom,
@@ -6618,7 +6618,7 @@ libvirt_virConnectDomainEventAgentLifecycleCallback(virConnectPtr conn ATTRIBUTE
return ret;
}
-#endif /* LIBVIR_CHECK_VERSION(1, 2, 11) */
+#endif /* VIR_DOMAIN_EVENT_ID_AGENT_LIFECYCLE */
static PyObject *
@@ -6676,9 +6676,9 @@ libvirt_virConnectDomainEventRegisterAny(ATTRIBUTE_UNUSED PyObject *self,
cb = VIR_DOMAIN_EVENT_CALLBACK(libvirt_virConnectDomainEventGenericCallback);
break;
case VIR_DOMAIN_EVENT_ID_BLOCK_JOB:
-#if LIBVIR_CHECK_VERSION(1, 2, 6)
+#ifdef VIR_DOMAIN_EVENT_ID_BLOCK_JOB_2
case VIR_DOMAIN_EVENT_ID_BLOCK_JOB_2:
-#endif /* LIBVIR_CHECK_VERSION(1, 2, 6) */
+#endif /* VIR_DOMAIN_EVENT_ID_BLOCK_JOB_2 */
cb = VIR_DOMAIN_EVENT_CALLBACK(libvirt_virConnectDomainEventBlockJobCallback);
break;
case VIR_DOMAIN_EVENT_ID_DISK_CHANGE:
@@ -6693,31 +6693,31 @@ libvirt_virConnectDomainEventRegisterAny(ATTRIBUTE_UNUSED PyObject *self,
case VIR_DOMAIN_EVENT_ID_PMSUSPEND:
cb = VIR_DOMAIN_EVENT_CALLBACK(libvirt_virConnectDomainEventPMSuspendCallback);
break;
-#if LIBVIR_CHECK_VERSION(0, 10, 0)
+#ifdef VIR_DOMAIN_EVENT_ID_BALLOON_CHANGE
case VIR_DOMAIN_EVENT_ID_BALLOON_CHANGE:
cb = VIR_DOMAIN_EVENT_CALLBACK(libvirt_virConnectDomainEventBalloonChangeCallback);
break;
-#endif /* LIBVIR_CHECK_VERSION(0, 10, 0) */
-#if LIBVIR_CHECK_VERSION(1, 0, 0)
+#endif /* VIR_DOMAIN_EVENT_ID_BALLOON_CHANGE */
+#ifdef VIR_DOMAIN_EVENT_ID_PMSUSPEND_DISK
case VIR_DOMAIN_EVENT_ID_PMSUSPEND_DISK:
cb = VIR_DOMAIN_EVENT_CALLBACK(libvirt_virConnectDomainEventPMSuspendDiskCallback);
break;
-#endif /* LIBVIR_CHECK_VERSION(1, 0, 0) */
-#if LIBVIR_CHECK_VERSION(1, 1, 1)
+#endif /* VIR_DOMAIN_EVENT_ID_PMSUSPEND_DISK */
+#ifdef VIR_DOMAIN_EVENT_ID_DEVICE_REMOVED
case VIR_DOMAIN_EVENT_ID_DEVICE_REMOVED:
cb = VIR_DOMAIN_EVENT_CALLBACK(libvirt_virConnectDomainEventDeviceRemovedCallback);
break;
-#endif /* LIBVIR_CHECK_VERSION(1, 1, 1) */
-#if LIBVIR_CHECK_VERSION(1, 2, 9)
+#endif /* VIR_DOMAIN_EVENT_ID_DEVICE_REMOVED */
+#ifdef VIR_DOMAIN_EVENT_ID_TUNABLE
case VIR_DOMAIN_EVENT_ID_TUNABLE:
cb = VIR_DOMAIN_EVENT_CALLBACK(libvirt_virConnectDomainEventTunableCallback);
break;
-#endif /* LIBVIR_CHECK_VERSION(1, 2, 9) */
-#if LIBVIR_CHECK_VERSION(1, 2, 11)
+#endif /* VIR_DOMAIN_EVENT_ID_TUNABLE */
+#ifdef VIR_DOMAIN_EVENT_ID_AGENT_LIFECYCLE
case VIR_DOMAIN_EVENT_ID_AGENT_LIFECYCLE:
cb = VIR_DOMAIN_EVENT_CALLBACK(libvirt_virConnectDomainEventAgentLifecycleCallback);
break;
-#endif /* LIBVIR_CHECK_VERSION(1, 2, 11) */
+#endif /* VIR_DOMAIN_EVENT_ID_AGENT_LIFECYCLE */
case VIR_DOMAIN_EVENT_ID_LAST:
break;
}
--
2.1.0
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