[Qemu-devel] [PATCH v2 04/14] qapi: better error message for bad enum

[Eric Blake <eblake@redhat.com>]

The previous commit demonstrated that the generator choked if an
enum forgot 'data', and silently ignored an enum where 'data'
was the wrong type.  Fix both cases to give a sane error message.

* scripts/qapi.py (parse_schema): Avoid bad deref.
(check_exprs): Check for array on enums.
* tests/qapi-schema/enum-missing-data.err: Update expected results.
* tests/qapi-schema/enum-wrong-data.*: Likewise.

Signed-off-by: Eric Blake <eblake@redhat.com>
---
 scripts/qapi.py                         | 16 ++++++++++++----
 tests/qapi-schema/enum-missing-data.err |  7 +------
 tests/qapi-schema/enum-wrong-data.err   |  1 +
 tests/qapi-schema/enum-wrong-data.exit  |  2 +-
 tests/qapi-schema/enum-wrong-data.out   |  3 ---
 5 files changed, 15 insertions(+), 14 deletions(-)

diff --git a/scripts/qapi.py b/scripts/qapi.py
index f2c6d1f..1082416 100644
--- a/scripts/qapi.py
+++ b/scripts/qapi.py
@@ -2,7 +2,7 @@
 # QAPI helper library
 #
 # Copyright IBM, Corp. 2011
-# Copyright (c) 2013 Red Hat Inc.
+# Copyright (c) 2013-2014 Red Hat Inc.
 #
 # Authors:
 #  Anthony Liguori <aliguori@us.ibm.com>
@@ -319,10 +319,18 @@ def check_union(expr, expr_info):
 def check_exprs(schema):
     for expr_elem in schema.exprs:
         expr = expr_elem['expr']
+        info = expr_elem['info']
+        members = expr.get('data')
+
         if expr.has_key('union'):
-            check_union(expr, expr_elem['info'])
+            check_union(expr, info)
         if expr.has_key('event'):
-            check_event(expr, expr_elem['info'])
+            check_event(expr, info)
+        if expr.has_key('enum'):
+            if not isinstance(members, list):
+                raise QAPIExprError(info,
+                                    "enum '%s' requires an array for 'data'"
+                                    % expr.get('enum'))

 def parse_schema(input_file):
     try:
@@ -336,7 +344,7 @@ def parse_schema(input_file):
     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'):
diff --git a/tests/qapi-schema/enum-missing-data.err b/tests/qapi-schema/enum-missing-data.err
index 1fec213..4912aab 100644
--- a/tests/qapi-schema/enum-missing-data.err
+++ b/tests/qapi-schema/enum-missing-data.err
@@ -1,6 +1 @@
-Traceback (most recent call last):
-  File "tests/qapi-schema/test-qapi.py", line 19, in <module>
-    exprs = parse_schema(sys.argv[1])
-  File "scripts/qapi.py", line 339, in parse_schema
-    add_enum(expr['enum'], expr['data'])
-KeyError: 'data'
+tests/qapi-schema/enum-missing-data.json:1: enum 'MyEnum' requires an array for 'data'
diff --git a/tests/qapi-schema/enum-wrong-data.err b/tests/qapi-schema/enum-wrong-data.err
index e69de29..857f0bd 100644
--- a/tests/qapi-schema/enum-wrong-data.err
+++ b/tests/qapi-schema/enum-wrong-data.err
@@ -0,0 +1 @@
+tests/qapi-schema/enum-wrong-data.json:1: enum 'MyEnum' requires an array for 'data'
diff --git a/tests/qapi-schema/enum-wrong-data.exit b/tests/qapi-schema/enum-wrong-data.exit
index 573541a..d00491f 100644
--- a/tests/qapi-schema/enum-wrong-data.exit
+++ b/tests/qapi-schema/enum-wrong-data.exit
@@ -1 +1 @@
-0
+1
diff --git a/tests/qapi-schema/enum-wrong-data.out b/tests/qapi-schema/enum-wrong-data.out
index 28d2211..e69de29 100644
--- a/tests/qapi-schema/enum-wrong-data.out
+++ b/tests/qapi-schema/enum-wrong-data.out
@@ -1,3 +0,0 @@
-[OrderedDict([('enum', 'MyEnum'), ('data', OrderedDict([('value', 'str')]))])]
-[{'enum_name': 'MyEnum', 'enum_values': OrderedDict([('value', 'str')])}]
-[]
-- 
1.9.3