[Qemu-devel] [PATCH V5 08/10] qapi script: do not allow string discriminator

[Wenchao Xia <xiawenc@linux.vnet.ibm.com>]

Signed-off-by: Wenchao Xia <xiawenc@linux.vnet.ibm.com>
---
 docs/qapi-code-gen.txt |    8 +++-----
 scripts/qapi-visit.py  |    6 ++++++
 2 files changed, 9 insertions(+), 5 deletions(-)

diff --git a/docs/qapi-code-gen.txt b/docs/qapi-code-gen.txt
index a2e7921..c92add9 100644
--- a/docs/qapi-code-gen.txt
+++ b/docs/qapi-code-gen.txt
@@ -123,11 +123,9 @@ And it looks like this on the wire:
 
 Flat union types avoid the nesting on the wire. They are used whenever a
 specific field of the base type is declared as the discriminator ('type' is
-then no longer generated). The discriminator can be a string field or a
-predefined enum field. If it is a string field, a hidden enum type will be
-generated as "[UNION_NAME]Kind". If it is an enum field, a compile time check
-will be done to verify the correctness. It is recommended to use an enum field.
-The above example can then be modified as follows:
+then no longer generated). The discriminator should be a predefined enum field,
+and a compile time check will be done to verify the correctness. The above
+example can then be modified as follows:
 
  { 'enum': 'BlockdevDriver', 'data': [ 'raw', 'qcow2' ] }
  { 'type': 'BlockdevCommonOptions',
diff --git a/scripts/qapi-visit.py b/scripts/qapi-visit.py
index 3240921..efa7ec3 100644
--- a/scripts/qapi-visit.py
+++ b/scripts/qapi-visit.py
@@ -280,6 +280,12 @@ def generate_visit_union(expr):
         # Use the predefined enum type as discriminator
         ret = ""
         discriminator_type_name = enum_define['enum_name']
+    elif discriminator:
+        # Do not allow string discriminator
+        sys.stderr.write("Discriminator '%s' is not a pre-defined enum "
+                         "type\n" %
+                         discriminator)
+        sys.exit(1)
     else:
         # There will always be a discriminator in the C switch code, by default it
         # is an enum type generated silently as "'%sKind' % (name)"
-- 
1.7.1