Re: [Qemu-devel] [PATCH v8 20/40] qapi: Better error messages for duplicated expressions

[Markus Armbruster]

Eric Blake <address@hidden> writes:

> On 05/05/2015 03:11 AM, Markus Armbruster wrote:
>> Eric Blake <address@hidden> writes:
>> 
>>> The previous commit demonstrated that the generator overlooked
>>> duplicate expressions:
>>> - a complex type or command reusing a built-in type name
>>> - redeclaration of a type name, whether by the same or different
>>> metatype
>>> - redeclaration of a command or event
>>> - collision of a type with implicit 'Kind' enum for a union
>>> - collision with an implicit MAX enum constant
>>>
>>> Since the c_type() function in the generator treats all names
>>> as being in the same namespace, this patch adds a global array
>>> to track all known names and their source, to prevent collisions
>>> before it can cause further problems.  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.
>>>
>
>>> +def add_name(name, info, meta, implicit = False):
>>> +    global all_names
>>> +    if name in all_names:
>>> +        raise QAPIExprError(info,
>>> +                            "%s '%s' is already defined"
>>> +                            %(all_names[name], name))
>> 
>> Let's put a space between binary operator % and its right operand.
>
> I was copying existing examples, but I can easily do a separate followup
> patch that unifies the style of % formatting (or switches to +
> concatenation where that is more legible).

That would be nice.

>>> +    if not implicit and name[-4:] == 'Kind':
>>> +        raise QAPIExprError(info,
>>> +                            "%s '%s' should not end in 'Kind'"
>>> +                            %(meta, name))
>> 
>> Likewise.  Can fix up on commit.
>
> Of course, I'll wait until any of your fixups in the pull request are
> already in place to write such a followup, to minimize rebase churn.

I'm working towards a pull request.  It has the appended cleanups
squashed into this patch and PATCH 40.



diff --git a/scripts/qapi.py b/scripts/qapi.py
index edfaf9e..166b74f 100644
--- a/scripts/qapi.py
+++ b/scripts/qapi.py
@@ -421,10 +421,10 @@ def check_member_clash(expr_info, base_name, data, source 
= ""):
     for key in data.keys():
         if key.startswith('*'):
             key = key[1:]
-        if key in base_members or "*%s" %key in base_members:
+        if key in base_members or "*" + key in base_members:
             raise QAPIExprError(expr_info,
                                 "Member name '%s'%s clashes with base '%s'"
-                                %(key, source, base_name))
+                                % (key, source, base_name))
     if base.get('base'):
         check_member_clash(expr_info, base['base'], data, source)
 
@@ -524,7 +524,7 @@ def check_union(expr, expr_info):
             branch_struct = find_struct(value)
             assert branch_struct
             check_member_clash(expr_info, base, branch_struct['data'],
-                               " of branch '%s'" %key)
+                               " of branch '%s'" % key)
 
         # If the discriminator names an enum type, then all members
         # of 'data' must also be members of the enum type.
@@ -800,11 +800,11 @@ def add_name(name, info, meta, implicit = False):
     if name in all_names:
         raise QAPIExprError(info,
                             "%s '%s' is already defined"
-                            %(all_names[name], name))
+                            % (all_names[name], name))
     if not implicit and name[-4:] == 'Kind':
         raise QAPIExprError(info,
                             "%s '%s' should not end in 'Kind'"
-                            %(meta, name))
+                            % (meta, name))
     all_names[name] = meta
 
 def add_struct(definition, info):