qapi: Better error messages for bad enums
The previous commit demonstrated that the generator had several
flaws with less-than-perfect enums:
- an enum that listed the same string twice (or two variant
strings that map to the same C enumerator) ended up generating
an invalid C enum
- because the generator adds a _MAX terminator to each enum,
the use of an enum member 'max' can also cause this clash
- if an enum omits 'data', the generator left a python stack
trace rather than a graceful message
- an enum that used a non-array 'data' was silently accepted by
the parser
- an enum that used non-string members in the 'data' member
was silently accepted by the parser
Add check_enum to cover these situations, and update testcases
to match. While valid .json files won't trigger any of these
cases, we might as well be nicer to developers that make a typo
while trying to add new QAPI code.
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
diff --git a/scripts/qapi.py b/scripts/qapi.py
index 20ee505..3ce8c33 100644
--- a/scripts/qapi.py
+++ b/scripts/qapi.py
@@ -311,13 +311,37 @@
# Todo: add checking for values. Key is checked as above, value can be
# also checked here, but we need more functions to handle array case.
+def check_enum(expr, expr_info):
+ name = expr['enum']
+ members = expr.get('data')
+ values = { 'MAX': '(automatic)' }
+
+ if not isinstance(members, list):
+ raise QAPIExprError(expr_info,
+ "Enum '%s' requires an array for 'data'" % name)
+ for member in members:
+ if not isinstance(member, str):
+ raise QAPIExprError(expr_info,
+ "Enum '%s' member '%s' is not a string"
+ % (name, member))
+ key = _generate_enum_string(member)
+ if key in values:
+ raise QAPIExprError(expr_info,
+ "Enum '%s' member '%s' clashes with '%s'"
+ % (name, member, values[key]))
+ values[key] = member
+
def check_exprs(schema):
for expr_elem in schema.exprs:
expr = expr_elem['expr']
- if expr.has_key('union'):
- check_union(expr, expr_elem['info'])
- if expr.has_key('event'):
- check_event(expr, expr_elem['info'])
+ info = expr_elem['info']
+
+ if expr.has_key('enum'):
+ check_enum(expr, info)
+ elif expr.has_key('union'):
+ check_union(expr, info)
+ elif expr.has_key('event'):
+ check_event(expr, info)
def parse_schema(input_file):
try:
@@ -331,7 +355,7 @@
for expr_elem in schema.exprs:
expr = expr_elem['expr']
if expr.has_key('enum'):
- add_enum(expr['enum'], expr['data'])
+ add_enum(expr['enum'], expr.get('data'))
elif expr.has_key('union'):
add_union(expr)
elif expr.has_key('type'):