[PULL 26/37] qapi: Improve reporting of lexical errors

[Markus Armbruster <armbru@redhat.com>]

Show text up to next structural character, whitespace, or quote
character instead of just the first character.

Forgotten quotes now get reported like "Stray 'command'" instead of
"Stray 'c'".

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20190914153506.2151-9-armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
---
 scripts/qapi/common.py             | 6 +++++-
 tests/qapi-schema/bad-type-int.err | 2 +-
 tests/qapi-schema/funny-word.err   | 2 +-
 3 files changed, 7 insertions(+), 3 deletions(-)

diff --git a/scripts/qapi/common.py b/scripts/qapi/common.py
index 142ab276ff..b3383b17ef 100644
--- a/scripts/qapi/common.py
+++ b/scripts/qapi/common.py
@@ -559,7 +559,11 @@ class QAPISchemaParser(object):
                 self.line += 1
                 self.line_pos = self.cursor
             elif not self.tok.isspace():
-                raise QAPIParseError(self, "Stray '%s'" % self.tok)
+                # Show up to next structural, whitespace or quote
+                # character
+                match = re.match('[^[\\]{}:,\\s\'"]+',
+                                 self.src[self.cursor-1:])
+                raise QAPIParseError(self, "Stray '%s'" % match.group(0))
 
     def get_members(self):
         expr = OrderedDict()
diff --git a/tests/qapi-schema/bad-type-int.err b/tests/qapi-schema/bad-type-int.err
index 2021fda5d1..9b2c12c1eb 100644
--- a/tests/qapi-schema/bad-type-int.err
+++ b/tests/qapi-schema/bad-type-int.err
@@ -1 +1 @@
-tests/qapi-schema/bad-type-int.json:3:13: Stray '1'
+tests/qapi-schema/bad-type-int.json:3:13: Stray '123'
diff --git a/tests/qapi-schema/funny-word.err b/tests/qapi-schema/funny-word.err
index 18aedb4a99..af92fe2551 100644
--- a/tests/qapi-schema/funny-word.err
+++ b/tests/qapi-schema/funny-word.err
@@ -1 +1 @@
-tests/qapi-schema/funny-word.json:1:3: Stray 'c'
+tests/qapi-schema/funny-word.json:1:3: Stray 'command'
-- 
2.21.0