qapi: Lift error reporting from QAPISchema.__init__() to callers

Backports commit 181feaf3555136dd7883e2434c4498ca1939bf1a from qemu

qemu/scripts/qapi-gen.py

@@ -8,7 +8,7 @@ from __future__ import print_function
 import argparse
 import re
 import sys
-from qapi.common import QAPISchema
+from qapi.common import QAPIError, QAPISchema
 from qapi.types import gen_types
 from qapi.visit import gen_visit
 # Unicorn: commented out
@@ -40,7 +40,11 @@ def main(argv):
               file=sys.stderr)
         sys.exit(1)
 
-    schema = QAPISchema(args.schema)
+    try:
+        schema = QAPISchema(args.schema)
+    except QAPIError as err:
+        print(err, file=sys.stderr)
+        exit(1)
 
     gen_types(schema, args.output_dir, args.prefix, args.builtins)
     gen_visit(schema, args.output_dir, args.prefix, args.builtins)

qemu/scripts/qapi/common.py

@@ -16,7 +16,6 @@ import errno
 import os
 import re
 import string
-import sys
 try:
     from collections import OrderedDict
 except:
@@ -1468,19 +1467,15 @@ class QAPISchemaEvent(QAPISchemaEntity):
 
 class QAPISchema(object):
     def __init__(self, fname):
-        try:
-            parser = QAPISchemaParser(open(fname, 'r'))
-            exprs = check_exprs(parser.exprs)
-            self.docs = parser.docs
-            self._entity_dict = {}
-            self._predefining = True
-            self._def_predefineds()
-            self._predefining = False
-            self._def_exprs(exprs)
-            self.check()
-        except QAPIError as err:
-            print(err, file=sys.stderr)
-            exit(1)
+        parser = QAPISchemaParser(open(fname, 'r'))
+        exprs = check_exprs(parser.exprs)
+        self.docs = parser.docs
+        self._entity_dict = {}
+        self._predefining = True
+        self._def_predefineds()
+        self._predefining = False
+        self._def_exprs(exprs)
+        self.check()
 
     def _def_entity(self, ent):
         # Only the predefined types are allowed to not have info