[Qemu-devel] [PATCH 6/9] qapi.py: Fix schema parser to check syntax systematically

[Markus Armbruster <armbru@redhat.com>]

Fixes at least the following parser bugs:

* accepts any token in place of a colon

* treats comma as optional

* crashes when closing braces or brackets are missing

Signed-off-by: Markus Armbruster <armbru@redhat.com>
---
 scripts/qapi.py                       | 40 ++++++++++++++++++++++++++---------
 tests/qapi-schema/missing-colon.err   |  1 +
 tests/qapi-schema/missing-colon.exit  |  2 +-
 tests/qapi-schema/missing-colon.out   |  3 ---
 tests/qapi-schema/missing-comma.err   |  1 +
 tests/qapi-schema/missing-comma.exit  |  2 +-
 tests/qapi-schema/missing-comma.out   |  3 ---
 tests/qapi-schema/unclosed-object.err |  2 +-
 8 files changed, 35 insertions(+), 19 deletions(-)

diff --git a/scripts/qapi.py b/scripts/qapi.py
index f72a0e3..a7feccb 100644
--- a/scripts/qapi.py
+++ b/scripts/qapi.py
@@ -91,24 +91,42 @@ class QAPISchema:
 
     def get_members(self):
         expr = OrderedDict()
-        while self.tok != '}':
+        if self.tok == '}':
+            self.accept()
+            return expr
+        if self.tok != "'":
+            raise QAPISchemaError(self, 'Expected string or "}"')
+        while True:
             key = self.val
             self.accept()
-            self.accept()        # :
+            if self.tok != ':':
+                raise QAPISchemaError(self, 'Expected ":"')
+            self.accept()
             expr[key] = self.get_expr()
-            if self.tok == ',':
+            if self.tok == '}':
                 self.accept()
-        self.accept()
-        return expr
+                return expr
+            if self.tok != ',':
+                raise QAPISchemaError(self, 'Expected "," or "}"')
+            self.accept()
+            if self.tok != "'":
+                raise QAPISchemaError(self, 'Expected string')
 
     def get_values(self):
         expr = []
-        while self.tok != ']':
+        if self.tok == ']':
+            self.accept()
+            return expr
+        if not self.tok in [ '{', '[', "'" ]:
+            raise QAPISchemaError(self, 'Expected "{", "[", "]" or string')
+        while True:
             expr.append(self.get_expr())
-            if self.tok == ',':
+            if self.tok == ']':
                 self.accept()
-        self.accept()
-        return expr
+                return expr
+            if self.tok != ',':
+                raise QAPISchemaError(self, 'Expected "," or "]"')
+            self.accept()
 
     def get_expr(self):
         if self.tok == '{':
@@ -117,9 +135,11 @@ class QAPISchema:
         elif self.tok == '[':
             self.accept()
             expr = self.get_values()
-        else:
+        elif self.tok == "'":
             expr = self.val
             self.accept()
+        else:
+            raise QAPISchemaError(self, 'Expected "{", "[" or string')
         return expr
 
 def parse_schema(fp):
diff --git a/tests/qapi-schema/missing-colon.err b/tests/qapi-schema/missing-colon.err
index e69de29..9f2a355 100644
--- a/tests/qapi-schema/missing-colon.err
+++ b/tests/qapi-schema/missing-colon.err
@@ -0,0 +1 @@
+<stdin>:1:10: Expected ":"
diff --git a/tests/qapi-schema/missing-colon.exit b/tests/qapi-schema/missing-colon.exit
index 573541a..d00491f 100644
--- a/tests/qapi-schema/missing-colon.exit
+++ b/tests/qapi-schema/missing-colon.exit
@@ -1 +1 @@
-0
+1
diff --git a/tests/qapi-schema/missing-colon.out b/tests/qapi-schema/missing-colon.out
index e67068c..e69de29 100644
--- a/tests/qapi-schema/missing-colon.out
+++ b/tests/qapi-schema/missing-colon.out
@@ -1,3 +0,0 @@
-[OrderedDict([('enum', None), ('data', ['good', 'bad', 'ugly'])])]
-[None]
-[]
diff --git a/tests/qapi-schema/missing-comma.err b/tests/qapi-schema/missing-comma.err
index e69de29..b0121b5 100644
--- a/tests/qapi-schema/missing-comma.err
+++ b/tests/qapi-schema/missing-comma.err
@@ -0,0 +1 @@
+<stdin>:2:3: Expected "," or "}"
diff --git a/tests/qapi-schema/missing-comma.exit b/tests/qapi-schema/missing-comma.exit
index 573541a..d00491f 100644
--- a/tests/qapi-schema/missing-comma.exit
+++ b/tests/qapi-schema/missing-comma.exit
@@ -1 +1 @@
-0
+1
diff --git a/tests/qapi-schema/missing-comma.out b/tests/qapi-schema/missing-comma.out
index e3bd904..e69de29 100644
--- a/tests/qapi-schema/missing-comma.out
+++ b/tests/qapi-schema/missing-comma.out
@@ -1,3 +0,0 @@
-[OrderedDict([('enum', 'Status'), ('data', ['good', 'bad', 'ugly'])])]
-['Status']
-[]
diff --git a/tests/qapi-schema/unclosed-object.err b/tests/qapi-schema/unclosed-object.err
index f9a9c2a..cc11626 100644
--- a/tests/qapi-schema/unclosed-object.err
+++ b/tests/qapi-schema/unclosed-object.err
@@ -1 +1 @@
-Crashed: <type 'exceptions.IndexError'>
+<stdin>:1:19: Expected "," or "]"
-- 
1.7.11.7