qapi: Unit tests for visitor-based serialization

Currently we test our visitors individually, and seperately for input
vs. output. This is useful for validating internal representations
against the native C types and vice-versa, and other visitor-specific
testing, but it doesn't cover the potential use-case of using visitor
pairs for serialization/deserialization very well, and makes it
hard to easily extend the coverage for different C types / boundary
conditions.

To cover that we add a set of unit tests that takes a number of native C
values, passes them into an output visitor, extracts the values with an
input visitor, then compares the result to the original.

Plugging in new visitors to the test harness only requires a user to
implement the SerializeOps interface and add it to a list.
Signed-off-by: NMichael Roth <mdroth@linux.vnet.ibm.com>
Signed-off-by: NAndreas Färber <afaerber@suse.de>

tests/Makefile

@@ -13,6 +13,7 @@ check-unit-y += tests/test-qmp-commands$(EXESUF)
 check-unit-y += tests/test-string-input-visitor$(EXESUF)
 check-unit-y += tests/test-string-output-visitor$(EXESUF)
 check-unit-y += tests/test-coroutine$(EXESUF)
+check-unit-y += tests/test-visitor-serialization$(EXESUF)
 
 check-block-$(CONFIG_POSIX) += tests/qemu-iotests-quick.sh
 
@@ -31,7 +32,7 @@ test-obj-y = tests/check-qint.o tests/check-qstring.o tests/check-qdict.o \
 	tests/test-coroutine.o tests/test-string-output-visitor.o \
 	tests/test-string-input-visitor.o tests/test-qmp-output-visitor.o \
 	tests/test-qmp-input-visitor.o tests/test-qmp-input-strict.o \
-	tests/test-qmp-commands.o
+	tests/test-qmp-commands.o tests/test-visitor-serialization.o
 
 test-qapi-obj-y =  $(qobject-obj-y) $(qapi-obj-y) $(tools-obj-y)
 test-qapi-obj-y += tests/test-qapi-visit.o tests/test-qapi-types.o
@@ -64,6 +65,7 @@ tests/test-qmp-output-visitor$(EXESUF): tests/test-qmp-output-visitor.o $(test-q
 tests/test-qmp-input-visitor$(EXESUF): tests/test-qmp-input-visitor.o $(test-qapi-obj-y)
 tests/test-qmp-input-strict$(EXESUF): tests/test-qmp-input-strict.o $(test-qapi-obj-y)
 tests/test-qmp-commands$(EXESUF): tests/test-qmp-commands.o tests/test-qmp-marshal.o $(test-qapi-obj-y)
+tests/test-visitor-serialization$(EXESUF): tests/test-visitor-serialization.o $(test-qapi-obj-y)
 
 tests/rtc-test$(EXESUF): tests/rtc-test.o $(trace-obj-y)
 tests/m48t59-test$(EXESUF): tests/m48t59-test.o $(trace-obj-y)