r218006 - Sema: Diagnose undefined structs used as Microsoft anonymous structs

[jahanian]

Thank you for clarifying.
- Fariborz

On Sep 18, 2014, at 9:41 AM, David Majnemer <david.majnemer at gmail.com> wrote:

> Yes, this change was done intentionally to be compatible with their behavior:
> 
> Microsoft (R) C/C++ Optimizing Compiler Version 19.00.22013.1 for x64
> Copyright (C) Microsoft Corporation.  All rights reserved.
> 
> anon.c
> anon.c(2): error C2027: use of undefined type 'undefined'
> anon.c(2): note: see declaration of 'undefined'
> 
> 
> 
> On Thu, Sep 18, 2014 at 9:38 AM, jahanian <fjahanian at apple.com> wrote:
> 
> On Sep 18, 2014, at 9:33 AM, jahanian <fjahanian at apple.com> wrote:
> 
>> 
>> On Sep 17, 2014, at 5:42 PM, David Majnemer <david.majnemer at gmail.com> wrote:
>> 
>>> Author: majnemer
>>> Date: Wed Sep 17 19:42:05 2014
>>> New Revision: 218006
>>> 
>>> URL: http://llvm.org/viewvc/llvm-project?rev=218006&view=rev
>>> Log:
>>> Sema: Diagnose undefined structs used as Microsoft anonymous structs
>>> 
>>> Previously, we would not mark structs containing anonymous structs as
>>> invalid.  Later, horrific things would occur when trying to determine
>>> the size of the parent record.
>>> 
>>> Instead, require the struct to be a complete type when used as an
>>> anonymous struct.  Mark both the anonymous field for the struct and the
>>> parent context as invalid (this is similar to what we do when a struct
>>> contains a field with an incomplete type.)
>> 
>> 
>> Thank you David for working on this. Will this test case continue to work without error. This was the behavior before:
>> 
>> struct anon_fault {
>> 	struct undefined;
>> };
>> 
>> struct undefined {
>>   int ii;
>> };
>> 
>> int main()
>> {
>>   return sizeof(struct anon_fault);
>> }
>> 
> 
> We get the error with your patch:
> 
> t.c:2:2: error: field has incomplete type 'struct undefined'
> t.c:2:9: note: forward declaration of 'struct undefined'
>         struct undefined;
>                ^
> I am not familiar with details of microsoft’s anonymous structs. Is this the expected behavior?
> 
> - Thanks, Fariborz
> 
> 
> 
> 

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.llvm.org/pipermail/cfe-commits/attachments/20140918/064598d8/attachment.html>